顔写真

タカタ マサキ
高田 昌樹
Masaki Takata
所属
国際放射光イノベーション・スマート研究センター 基幹研究部門 機能情報計測スマートラボ
職名
教授
学位
  • 理学博士(広島大学)

  • 理学修士(広島大学)

e-Rad 研究者番号
60197100
Researcher ID

経歴 13

  • 2020年7月 ~ 継続中
    東北大学 国際放射光イノベーション・スマート研究センター 教授

  • 2017年 ~ 継続中
    (一財)光科学イノベーションセンター 理事長

  • 2015年7月 ~ 継続中
    東北大学 総長特別補佐(研究担当)

  • 2015年4月 ~ 継続中
    東北大学 多元物質科学研究所 教授

  • 2016年10月 ~ 2017年3月
    九州大学 先導物質化学研究所 客員教授

  • 2010年4月 ~ 2015年3月
    特定国立研究開発法人理化学研究所 放射光科学総合研究センター 副センター長

  • 2007年4月 ~ 2015年3月
    東京大学 大学院新領域創成科学研究科 客員教授

  • 2006年4月 ~ 2015年3月
    特定国立研究開発法人理化学研究所 放射光科学総合研究センター 主任研究員

  • 2003年10月 ~ 2006年3月
    公益財団法人高輝度光科学研究センター 主席研究員

  • 1999年8月 ~ 2003年9月
    名古屋大学 大学院工学研究科 助教授

  • 2000年4月 ~ 2002年3月
    公益財団法人豊田理化学研究所 研究員

  • 1997年4月 ~ 1999年7月
    島根大学 総合理工学部 助教授

  • 1987年4月 ~ 1997年3月
    名古屋大学 工学部 助手

︎全件表示 ︎最初の5件までを表示

学歴 2

  • 広島大学 大学院理学研究科 物性学専攻

    1982年4月 ~ 1987年3月

  • 広島大学 理学部 物性学科

    1978年4月 ~ 1982年3月

委員歴 18

  • 日本放射光学会 評議員

    2019年10月 ~ 継続中

  • ESRF Science Advisory Committee

    2018年 ~ 継続中

  • Royal Society of Chemistry Fellow

    2014年10月 ~ 継続中

  • International Union of Crystallography Executive Committee Member

    2014年9月 ~ 継続中

  • 日本放射光学会 評議員

    2010年10月 ~ 2015年9月

  • 日本結晶学会 評議員

    2013年4月 ~ 2015年3月

  • ESRF Science Advisory Committee

    2013年 ~ 2015年

  • 日本結晶学会 評議員

    2006年4月 ~ 2012年3月

  • 日本結晶学会 編集幹事

    2008年4月 ~ 2010年3月

  • 日本放射光学会 評議員

    2007年1月 ~ 2008年12月

  • 日本放射光学会 庶務幹事

    2005年1月 ~ 2006年12月

  • 日本結晶学会 編集幹事

    2004年4月 ~ 2006年3月

  • 日本結晶学会 庶務幹事

    2004年4月 ~ 2006年3月

  • 日本結晶学会 評議員

    1999年4月 ~ 2005年3月

  • 日本放射光学会 行事幹事

    2003年1月 ~ 2004年12月

  • 日本放射光学会 評議員

    2003年1月 ~ 2004年12月

  • 日本結晶学会 広報幹事

    2000年4月 ~ 2004年3月

  • 日本放射光学会 編集委員

    2000年4月 ~ 2002年3月

︎全件表示 ︎最初の5件までを表示

所属学協会 6

  • 応用物理学会

  • フラーレン・ナノチューブ・グラフェン学会

  • 日本金属学会

  • 日本放射光学会

  • 日本結晶学会

  • 日本物理学会

︎全件表示 ︎最初の5件までを表示

研究キーワード 5

  • 電子密度解析

  • 構造物性科学

  • 次世代放射光

  • マキシマムエントロピー法

  • 粉末X線回折

研究分野 4

  • ナノテク・材料 / 結晶工学 /

  • ナノテク・材料 / 応用物性 /

  • 自然科学一般 / 磁性、超伝導、強相関系 /

  • 自然科学一般 / 半導体、光物性、原子物理 /

受賞 8

  1. 令和3年度錯体化学会「貢献賞」

    2021年9月 錯体化学会 放射光科学と最大エントロピー法による錯体構造化学の革新

  2. 令和元年度 手島精一記念研究賞 研究論文賞

    2020年2月 東京工業大学

  3. Fellow of the Royal Society of Chemistry

    2014年 Royal Society of Chemistry

  4. 科学技術賞(研究部門)

    2013年4月 文部科学大臣 微量粉末から物質の機能を可視化する放射光構造科学の研究

  5. 第34回応用物理学会論文賞

    2012年9月 応用物理学会

  6. ひょうごSPring-8賞

    2004年10月 (財)ひょうご科学技術協会 新機軸の粉末回折法の開発による物質科学への貢献

  7. 日本物理学会第6回論文賞

    2001年3月 日本物理学会

  8. 日本結晶学会賞

    1998年11月 日本結晶学会 X線回折法による金属内包フラーレンの構造研究

︎全件表示 ︎最初の5件までを表示

論文 611

  1. 社会課題解決に貢献する次世代放射光施設ナノテラス

    高田 昌樹

    応用物理 93 (1) 5-11 2024年1月

    DOI: 10.11470/oubutsu.93.1_5  

  2. X 線は電子のプローブである- 放射光科学と最大エントロピー法による錯体構造化学の革新-

    高田昌樹

    79 101-105 2022年7月

    DOI: 10.4019/bjscc.79.100  

  3. Hydrogen bonding propagated phase separation in quasi-epitaxial single crystals: a Pd-Br molecular insulator

    Takefumi Yoshida, Shinya Takaishi, Laurent Guérin, Tatsuhiro Kojima, Hiroyoshi Ohtsu, Masaki Kawano, Tatsuya Miyamoto, Hiroshi Okamoto, Kenichi Kato, Masaki Takata, Yuka Hosomi, Shoji Yoshida, Hidemi Shigekawa, Hisaaki Tanaka, Shin-ichi Kuroda, Hiroaki Iguchi, Brian Breedlove, Zhao-Yang Li, Masahiro Yamashita

    2022年5月11日

    出版者・発行元:Research Square Platform {LLC}

    DOI: 10.21203/rs.3.rs-1579855/v1  

  4. Measuring the shock stage of Itokawa and asteroid regolith grains by electron backscattered diffraction, optical petrography, and synchrotron X‐ray diffraction

    Michael Zolensky, James Martinez, Scott Sitzman, Takashi Mikouchi, Kenji Hagiya, Kazumasa Ohsumi, Mutsumi Komatsu, Tomoki Nakamura, Atsushi Takenouchi, Haruka Ono, Hikari Hasegawa, Kotaro Higashi, Yasuko Terada, Naoto Yagi, Masaki Takata, Hikaru Ozawa, Yuta Taki, Yuta Yamatsuta, Arashi Hirata, Ayaka Kurokawa, Shoki Yamaguchi

    Meteoritics & Planetary Science 57 (5) 1060-1078 2022年5月

    出版者・発行元:Wiley

    DOI: 10.1111/maps.13808  

    ISSN:1086-9379

    eISSN:1945-5100

  5. Metagenomic mining and structure-function studies of a hyper-thermostable cellobiohydrolase from hot spring sediment

    Migiwa Takeda, Seiki Baba, Jiro Okuma, Yoshitsugu Hirose, Asuka Nishimura, Masaki Takata, Kohei Oda, Daisuke Shibata, Takashi Kumasaka, Yasuhiro Kondo

    Communications Biology 5 (1) 2022年3月22日

    出版者・発行元:Springer Science and Business Media LLC

    DOI: 10.1038/s42003-022-03195-1  

    eISSN:2399-3642

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    Abstract Enzymatic breakdown is an attractive cellulose utilisation method with a low environmental load. Its high temperature operation could promote saccharification and lower contamination risk. Here we report a hyper-thermostable cellobiohydrolase (CBH), named HmCel6A and its variant HmCel6A-3SNP that were isolated metagenomically from hot spring sediments and expressed in Escherichia coli. They are classified into glycoside hydrolases family 6 (GH6). HmCel6A-3SNP had three amino acid replacements to HmCel6A (P88S/L230F/F414S) and the optimum temperature at 95 °C, while HmCel6A did it at 75 °C. Crystal structure showed conserved features among GH6, a (β/α)<sub>8</sub>-barrel core and catalytic residues, and resembles TfCel6B, a bacterial CBH II of Thermobifida fusca, that had optimum temperature at 60 °C. From structure-function studies, we discuss unique structural features that allow the enzyme to reach its high thermostability level, such as abundance of hydrophobic and charge-charge interactions, characteristic metal bindings and disulphide bonds. Moreover, structure and surface plasmon resonance analysis with oligosaccharides suggested that the contribution of an additional tryptophan located at the tunnel entrance could aid in substrate recognition and thermostability. These results may help to design efficient enzymes and saccharification methods for cellulose working at high temperatures.

  6. 次世代放射光施設の特徴と利活用に向けた取り組み

    原田 昌彦, 高田 昌樹, 村松 淳司

    オレオサイエンス 22 (2) 55-60 2022年

    出版者・発行元:公益社団法人 日本油化学会

    DOI: 10.5650/oleoscience.22.55  

    ISSN:1345-8949

    eISSN:2187-3461

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    東北大学キャンパス内に,2024年度の共用開始を目指して,次世代放射光施設が建設されています。既に基本建屋はほぼ完成し,加速器の設置が始まっています。食品,農学関係で用途の多い軟X線領域でSPring-8を100倍ともいわれる輝度のX線を利用できることが最大の特長です。それに加え,大学や一般財団法人が放射光利用をサポートする「コアリション・システム」も既存放射光施設にはない特徴であり,これらが産官学連携や学術研究に大きく貢献することが期待されます。本稿では,このような次世代放射光施設の特徴と,主に食・農領域における利活用の可能性について概説します。

  7. Complex Structural Disorder in a Polar Orthorhombic Perovskite Observed through the Maximum Entropy Method/Rietveld Technique

    Alicia María Manjón-Sanz, T. Wesley Surta, Pranab Mandal, Alex J. Corkett, Hongjun Niu, Eiji Nishibori, Masaki Takata, John Bleddyn Claridge, Matthew J. Rosseinsky

    Chemistry of Materials 34 (1) 29-42 2021年12月22日

    出版者・発行元:American Chemical Society (ACS)

    DOI: 10.1021/acs.chemmater.1c01979  

    ISSN:0897-4756

    eISSN:1520-5002

  8. Mechanism of Elastic Properties of Biodegradable Poly[(R)-3-Hydroxybutyrate-co-4-hydroxybutyrate] Films Revealed by Synchrotron Radiation 査読有り

    Yuki Kawamura, Hongyi Gan, Taizo Kabe, Akira Maehara, Satoshi Kimura, Takaaki Hikima, Masaki Takata, Tadahisa Iwata

    ACS Omega 6 (11) 7387-7393 2021年3月23日

    出版者・発行元:American Chemical Society (ACS)

    DOI: 10.1021/acsomega.0c05662  

    ISSN:2470-1343

    eISSN:2470-1343

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    Reversible elastic films of biobased and biodegradable poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate] [P(3HB-co-4HB)] were prepared by uniaxial drawing procedures. Mechanical properties and highly ordered film structures were investigated by tensile testing and both static-state and in situ wide-angle X-ray diffraction and small-angle X-ray scattering with synchrotron radiation during stretching and relaxing. Despite the crystalline nature of the polymers, the elongation at break of these films was greater than 1500%. Reversible elasticity was achieved after the first 10 times of uniaxial stretching. X-ray measurement results indicated that on stretching, beta-form molecular chains with a planar zigzag conformation were introduced from molecular chains with random coils in the amorphous regions between alpha-form lamellar crystals. Notably, the orientation of the alpha-form lamellar crystals increased after relaxation of the molecular chains with a planar zigzag conformation (beta-form) between the lamellar crystals (alpha-form). Reversible elastic properties were regenerated by a planar zigzag conformation between the lamellar crystals, the extension of molecular chains in lamellar crystals by the rotation of molecular conformation, and changes in the degree of orientation of the lamellar crystals.

  9. High‐Density Frenkel Defects as Origin of N‐Type Thermoelectric Performance and Low Thermal Conductivity in Mg 3 Sb 2 ‐Based Materials 査読有り

    Tsutomu Kanno, Hiromasa Tamaki, Masato Yoshiya, Hiroshi Uchiyama, Sachiko Maki, Masaki Takata, Yuzuru Miyazaki

    Advanced Functional Materials 31 (13) 2008469-2008469 2021年3月

    出版者・発行元:Wiley

    DOI: 10.1002/adfm.202008469  

    ISSN:1616-301X

    eISSN:1616-3028

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    Mg3Sb2-based intermetallic compounds with exceptionally high thermoelectric performance exhibit unconventional n-type dopability and anomalously low thermal conductivity, attracting much attention to the underlying mechanisms. To date, investigations have been limited to first-principle calculations and thermodynamic analysis of defect formation, and detailed experimental analysis on crystal structure and phonon modes has not been achieved. Here, a synchrotron X-ray diffraction study clarifies that, against a previous view of a simple crystal structure with a small unit cell, Mg3Sb2 is inherently a heavily disordered material with Frenkel defects, charge-neutral defect complexes of cation vacancies and interstitials. Ionic charge neutrality preserved in Mg3Sb2 is responsible for exotic n-type dopability, which is unachievable for other Zintl phase materials. The thermal conductivity of Mg3Sb2 exhibits deviation from the standard T−1 temperature dependency with strongly limited phonon transport due to a strain field. Inelastic X-ray scattering measurement reveals enhanced phonon scattering induced by disorder. The results will draw renewed attention to crystal defects and disorder as means to explore new high-performance thermoelectric materials.

  10. Changing the structural and physical properties of 3-arm star poly(δ-valerolactone)s by a branch-point design 査読有り

    Hibiki Ogiwara, Fumitaka Ishiwari, Tadahiro Kimura, Yukihiro Yamashita, Takashi Kajitani, Atsuki Sugimoto, Masatoshi Tokita, Masaki Takata, Takanori Fukushima

    Chemical Communications 57 (32) 3901-3904 2021年3月

    出版者・発行元:Royal Society of Chemistry (RSC)

    DOI: 10.1039/d1cc01092a  

    ISSN:1359-7345

    eISSN:1364-548X

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    <p>This study provides an answer to the question of whether polymer properties can be modulated by the design of branching points.</p>

  11. 9,9'-bi(xanthene)-type hexaphenylethane derivatives as advanced organic electrochromic systems

    Takanori Suzuki, Yusuke Ishigaki, Masaki Takata, Jun Ichi Nishida, Takanori Fukushima

    Heterocycles 102 (3) 419-450 2020年9月8日

    DOI: 10.3987/REV-20-938  

    ISSN:0385-5414

    eISSN:1881-0942

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    9-Phenylxanthenyl radical can undergo facile C-C bond formation at C9-position when the two units of the radical are connected at C2'-positions to give stable intramolecular dimer (1), which is a clamped hexaphenylethane derivative with an elongated C-C bond. The newly formed bond in 1 can be cleaved easily upon two-electron oxidation to give bis(9-xanthenylium)-type dication (22+), from which the diradical is generated upon two-electron reduction. This review account describes the dynamic redox ("dyrex") pair of colorless 1 and yellow-orange 22+, which provides a versatile scaffold to develop multi-functional electrochromic systems. Both of 1 and 22+ are sterically challenged molecules and thus adopt characteristic skewed geometries. Electrochiroptical response was realized by suppressing the chiral inversion of helicity in 1 and axial chirality in 22+ whereas redox-induced fluorescence switching was attained by attaching the fluorophore whose emission is quenched by xanthenylium in 22+ but not by spiro(xanthene) unit in 1. By the molecular design that allows intramolecular chiral transmission, the spectral changes were also induced by the external stimuli (e.g. heat, pH) other than redox input, which made it possible to construct less well-explored multi-input-multi-output response systems. More advanced functions could be endowed, such as chiral redox memory or reversible O2-storage, by further modification of the prototype.

  12. Dynamic observation of MoSiBTiC alloy phase transitions using in situ ultrahigh-temperature X-ray diffraction measurement 査読有り

    Hiroyuki Fukuyama, Makoto Ohtsuka, Ryogo Sawada, Haruki Nakashima, Yasuo Ohishi, Naohisa Hirao, Masaki Takata, Kyosuke Yoshimi

    Materialia 13 100867-100867 2020年9月

    出版者・発行元:Elsevier BV

    DOI: 10.1016/j.mtla.2020.100867  

    ISSN:2589-1529

    eISSN:2589-1529

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    In situ ultrahigh-temperature XRD measurement of a MoSiBTiC alloy was carried out using a laser-heated diamond anvil cell and synchrotron radiation. This technique revealed the complicated dynamic behavior of phase transitions in the MoSiBTiC alloy on heating above 1950 degrees C. The MoSiBTiC alloy initially consisted of Mo solid solution (Moss), Mo5B2Si (T-2), TiC, Mo2B, Mo3Si, and Mo2C phases. The Mo2B, Mo3Si, and Mo2C phases disappeared on heating at similar to 1647 degrees C. The Moss grains coarsened during heating and the Moss, TiC, and T-2 phases were present > 1950 degrees C. The obtained results verified the solidification pathway of the MoSiBTiC alloy. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of Acta Materialia Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

  13. Highly Transparent and Tough Filler Composite Elastomer Inspired by the Cornea 査読有り

    Kenta Watanabe, Eiji Miwa, Fumio Asai, Takahiro Seki, Kenji Urayama, Tomotaka Nakatani, So Fujinami, Taiki Hoshino, Masaki Takata, Chang Liu, Koichi Mayumi, Kohzo Ito, Yukikazu Takeoka

    ACS Materials Letters 2 (4) 325-330 2020年4月

    DOI: 10.1021/acsmaterialslett.9b00520  

    eISSN:2639-4979

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    © 2020 American Chemical Society. We propose a strategy to develop a colorless, transparent, and tough composite elastomer inspired by the cornea, which is the transparent front portion of the eyeball. The composite elastomer, in which 34 vol »% hard silica particles with a uniform particle size are dispersed as a filler in a low-crosslinking polymer network exhibits a fracture energy that is ∼13.5 times higher than that of a system without the silica particles. This strategy also makes the elastomer optically transparent, because the light scattered by each silica particle that forms an ordered structure in the polymer network is cancelled by interference. This research may pave the way for the development of optically transparent and durable materials for applications such as advanced medical devices and soft robots.

  14. Precise Synthesis of a Homogeneous Thermoresponsive Polymer Network Composed of Four-Branched Star Polymers with a Narrow Molecular Weight Distribution 査読有り

    Yuumi Okaya, Yuto Jochi, Takahiro Seki, Kotaro Satoh, Masami Kamigaito, Taiki Hoshino, Tomotaka Nakatani, So Fujinami, Masaki Takata, Yukikazu Takeoka

    Macromolecules 53 (1) 374-386 2020年1月14日

    DOI: 10.1021/acs.macromol.9b01616  

    ISSN:0024-9297

    eISSN:1520-5835

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    © 2019 American Chemical Society. In this study, the synthesis of a star-shaped polymer with a narrow molecular weight distribution and subsequent formation of a homogeneous polymer network composed of the star-shaped polymer were realized by combining single-electron transfer living radical polymerization, click reaction, and amide bond formation with a condensing agent, which are toolized reactions. First, a 4-armed star polymer consisting of N-isopropylacrylamide was synthesized by living radical polymerization using N,N′-ethylenebis (2,2-dichloroacetamide) as a 4-branched initiator. By this polymerization method, a terminal Cl 4-branched star poly(N-isopropylacrylamide) (PNIPA) with a narrow molecular weight distribution could be obtained, but it was found that the reaction activity of the polymer terminal was lost in the process of purification and isolation. Therefore, after obtaining the terminal Cl 4-branched star PNIPA by living radical polymerization, an azide reaction was carried out in one pot without purification and isolation of the star-shaped polymer. As a result, the azide group was successfully introduced to all ends of the star-shaped polymer. By introducing a carboxyl group or an amino group into the 4-branched star polymer with azide groups using a click reaction, two types of 4-branched star polymers with different end groups were obtained. Equal amounts of both 4-branched star polymers were mixed at a polymer concentration equal to or higher than the overlapping concentration, and as a result of forming an amide bond with a condensing agent, a polymer gel was obtained. The swelling behaviors of the polymer gel indicate that almost no unreacted carboxyl group or amino group was present in the obtained polymer gel. That is, it was found that both 4-branched star polymers reacted efficiently to form a polymer network. In addition, structural observation of the polymer network by the small-angle X-ray scattering method showed that a polymer gel consisting of a network of uniform size was obtained. As mentioned above, we succeeded in constructing a polymer gel consisting of a homogeneous network structure using a temperature-responsive 4-branched star polymer as the building block. The living radical polymerization method, the click reaction, and the amide formation by condensation reaction used in this study can be applied not only to the NIPA used here but also to various other monomers. If the construction of a precise network structure is realized by many polymers and the relation with the functional expression derived from the structure is clarified, it will be possible to design the network structure in accordance with the usage of the polymer gel.

  15. Morphological changes of hydrophobic matrix and hydrophilic ionomers in water-swollen perfluorinated sulfonic acid membranes detected using small-angle X-ray scattering 査読有り

    So Fujinami, Taiki Hoshino, Tomotaka Nakatani, Tatsuya Miyajima, Takaaki Hikima, Masaki Takata

    Polymer 180 2019年10月10日

    DOI: 10.1016/j.polymer.2019.121699  

    ISSN:0032-3861

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    © 2019 Elsevier Ltd Time-resolved small-angle X-ray scattering (SAXS) was employed to examine the hydration dynamics of perfluorinated sulfonic acid membranes in contact with liquid water. Following thermal pretreatment of the membranes, a peak corresponding to the fluorocarbon polymer backbones was clearly observed in the SAXS profiles, in addition to a peak corresponding to the ionomer clusters consisting of hydrophilic side chains and water molecules. The variation of these two peaks was monitored with a frame time as low as 21 ms, which permitted the successful capture of the subsecond dynamics of water uptake by 25 and 50 μm thick membranes. The dynamics of the initial rapid water uptake were well reproduced using Fick's equation, although the thinner sample exhibited a smaller diffusion coefficient. This result suggests that the surface resistance influences the diffusion of water into the membrane. The initial rapid water absorption was followed by the slow and continuous reconstruction of the polymer structure. The measured dynamics of the two peaks indicated that, during this long-term reconstruction, the increase in the ionomer volume became slower and the fusion of clusters was the dominant factor responsible for increasing the ionomer spacing.

  16. The Next Generation 3GeV Synchrotron Radiation Facility Project in Japan 招待有り 査読有り

    TAKATA MASAKI, MAKI SACHIKO, KANIE KIYOSHI, WATANABE MASASHI, ABUKAWA TADASHI, YASHIRO WATARU, TAKAHASHI YUKIO, FUKUYAMA HIROYUKI, MURAMATSU ATSUSHI, UTSUMI WATARU, TANAKA HITOSHI, NISHIMORI NOBUYUKI, TAKAHASHI MASAMITSU, Kado Masataka

    AAPPS Bulletin 29 (5) 26-30 2019年10月

  17. Crystal structures and crystalline elastic modulus of paramylon esters 査読有り

    Hongyi Gan, Taizo Kabe, Satoshi Kimura, Takaaki Hikima, Masaki Takata, Tadahisa Iwata

    Polymer 172 7-12 2019年5月20日

    DOI: 10.1016/j.polymer.2019.03.002  

    ISSN:0032-3861

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    © 2019 Elsevier Ltd Paramylon is a β-1,3-glucan photosynthesized by Euglena. In this study, the four paramylon ester derivatives, paramylon propionate (PaPr), paramylon butyrate (PaBu), paramylon valerate (PaVa), paramylon hexanoate (PaHe), were prepared and their crystal structures were determined by wide-angle X-ray diffraction. All of the reflections are indexed to a hexagonal crystal system and all of the molecular chains have five-fold screw symmetry along the molecular axes, despite of the different side-chain lengths of the ester groups. The crystal lattice parameters increase with increasing of side-chain length of the ester groups. The crystalline elastic modulus of PaPr, PaBu, and PaVa parallel to the fiber axis (E l ) were determined by time-resolved X-ray diffraction at SPring-8, which is a large synchrotron radiation facility. The crystalline elastic modulus of PaPr, PaBu, and PaVa are 2.5, 1.9, and 1.0 GPa, respectively. The decreasing E l values are mainly caused by increasing of cross-sectional area of the molecular chains, which is affected by the side-chain length. The E l values of the paramylon esters are one-tenth those of previously reported cellulose esters. This seems to be because of the different helical structure of the backbone chain.

  18. In Situ Tracking of Dynamic NO Capture through a Crystal-to-Crystal Transformation from a Gate-Open-Type Chain Porous Coordination Polymer to a NO-Adducted Discrete Isomer 査読有り

    Jun Zhang, Wataru Kosaka, Susumu Kitagawa, Masaki Takata, Hitoshi Miyasaka

    Chemistry - A European Journal 25 (12) 3020-3031 2019年2月26日

    DOI: 10.1002/chem.201805833  

    ISSN:0947-6539

    eISSN:1521-3765

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    © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Optimal control of gas adsorption properties in metal–organic frameworks (MOFs) or porous coordination polymers (PCPs) remains a great challenge in the field of materials science. An efficient strategy to capture electron-acceptor-type gas molecules such as nitrogen monooxide (NO) is to use host–guest interactions by utilizing electron-donor-type MOFs/PCPs as host frameworks. Herein, we focus on a highly electron-donating chain compound by using the paddlewheel-type [Ru 2II,II ] complex [Ru 2 (2,4,5-Me 3 PhCO 2 ) 4 ] (2,4,5-Me 3 PhCO 2− =2,4,5-trimethylbenzoate) with the phenazine (phz) linker: [Ru 2 (2,4,5-Me 3 PhCO 2 ) 4 (phz)] (1). Compound 1 exhibited a specific gated adsorption for NO under gas pressures greater than 60 kPa at 121 K, which finally resulted in approximately seven molar equivalents being taken up at 100 kPa followed by four molar equivalents remaining under vacuum at 121 K; its Rh isomorph (2) with weaker donation ability was inactive for NO. When the sample of 1⊃4 NO was heated to room temperature, the compound underwent a crystal-to-crystal phase transition to give [Ru 2 (2,4,5-Me 3 PhCO 2 ) 4 (NO) 2 ](phz) (1-NO), involving a post-synthetic nitrosylation on the [Ru 2 ] unit, accompanied by an eventful site-exchange with phz. This drastic event, which is dependent on the NO pressure, temperature, and time, was coherently monitored by using several different in situ techniques, revealing that the stabilization of NO molecules in nanosized pores dynamically and stepwisely occurred with the support of strong electronic/magnetic host–guest interactions.

  19. Chiral crystal-like droplets displaying unidirectional rotational sliding 査読有り

    Takashi Kajitani, Kyuri Motokawa, Atsuko Kosaka, Yoshiaki Shoji, Rie Haruki, Daisuke Hashizume, Takaaki Hikima, Masaki Takata, Koji Yazawa, Ken Morishima, Mitsuhiro Shibayama, Takanori Fukushima

    Nature Materials 18 (3) 266-272 2019年1月

    DOI: 10.1038/s41563-018-0270-7  

    ISSN:1476-1122

    eISSN:1476-4660

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    © 2019, The Author(s), under exclusive licence to Springer Nature Limited. The self-assembly of organic molecules into supramolecular materials with structural ordering beyond the nanometre scale is challenging. Here, we report the spontaneous self-assembly of a chiral discotic triphenylene derivative into millimetre-sized droplets. The structure of the droplets is characterized by high positional and orientational ordering and a three-dimensional integrity similar to that of single crystals. Notwithstanding, these assemblies slide when placed on a vertical substrate demonstrating their fluid nature. X-ray imaging shows that during the sliding process the internal crystal-like structure is maintained and that the droplets undergo clockwise or counterclockwise unidirectional rotation, depending on the chirality of their molecular components. Rheological measurements suggest that this rotational behaviour might result from the distinct yield stress between the (R)- and (S)-enantiomers. Overall, our findings demonstrate that molecular chirality can determine the movement direction of a supramolecular structure, thus expanding the fundamental understanding of the structure and dynamics of soft materials.

  20. Structural Modulations in the Intermediate Phase of Antiferroelectric PbHfO3 査読有り

    Hideshi Fujishita, Kenichi Kato, Eiji Nishibori, Masaki Takata, Makoto Sakata, Susumu Katano

    Journal of the Physical Society of Japan 87 (12) 124603-124603 2018年12月15日

    出版者・発行元:Physical Society of Japan

    DOI: 10.7566/jpsj.87.124603  

    ISSN:0031-9015

    eISSN:1347-4073

  21. Rewriting the phase diagram of a diamagnetic liquid crystal by a magnetic field 査読有り

    Fatin Hajjaj, Takashi Kajitani, Hiroyuki Ohsumi, Yoshikazu Tanaka, Kenichi Kato, Masaki Takata, Hideaki Kitazawa, Taka hisa Arima, Takuzo Aida, Takanori Fukushima

    Nature Communications 9 (1) 2018年12月1日

    DOI: 10.1038/s41467-018-06976-7  

    eISSN:2041-1723

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    © 2018, The Author(s). Magnetic fields have been considered to only interact with organic materials non-destructively, leaving their fundamental structures unaffected, even when a strong magnetic field generated from a superconducting magnet is applied. Here we report an unprecedented observation that a liquid-crystalline mesophase of a diamagnetic molecular assembly with an orthorhombic or a cubic structure is formed selectively in the absence or presence of a strong magnetic field. The constituent molecule is a triphenylene derivative carrying six imidazolium bromide-terminated alkyl side chains and exhibits a cubic, orthorhombic, or hexagonal columnar mesophase when complexed with an appropriate amount of lanthanum(III) bromide. Thermal processing of the La3+-containing liquid-crystalline assembly in the presence of a 10-tesla magnetic field resulted in a phase diagram, in which the orthorhombic phase is completely replaced with the cubic phase. The discovery of this magneto-induced phase-selection offers an insight into the interactions between magnetic fields and organic material.

  22. Terminal Functionalization with a Triptycene Motif That Dramatically Changes the Structural and Physical Properties of an Amorphous Polymer 査読有り

    Fumitaka Ishiwari, Gen Okabe, Hibiki Ogiwara, Takashi Kajitani, Masatoshi Tokita, Masaki Takata, Takanori Fukushima

    Journal of the American Chemical Society 140 (41) 13497-13502 2018年10月17日

    DOI: 10.1021/jacs.8b09242  

    ISSN:0002-7863

    eISSN:1520-5126

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    © Copyright 2018 American Chemical Society. A surprising terminal-group effect on the structural and physical properties of an amorphous polymer is reported. We recently demonstrated that triptycene derivatives with substituents at the 1,8,13-positions show specific self-assembly behavior, enabling the formation of a well-defined "2D + 1D" structure based on nested hexagonal packing of the triptycenes. Upon terminal functionalization with a 1,8-substituted triptycene (1,8-Trip), a liquid polymer, polydimethylsiloxane (PDMS, Mn = 18-24 kDa), turned into a highly viscous solid that exhibits birefringence at 25 °C. Small-angle and wide-angle X-ray scattering measurements revealed that the resulting telechelic PDMS assembles into a 2D + 1D structure, where layers of PDMS domains, formed between 2D assemblies of the triptycene termini, stack into a 1D multilayer structure with a layer spacing of 18-20 nm. Because of this structuring, the complex viscosity of the telechelic PDMS was dramatically enhanced, providing a value 4 orders of magnitude greater than that of the original PDMS. Remarkably, the structural and physical properties of PDMS were hardly changed upon terminal functionalization with another regioisomer of triptycene (1,4-Trip), which differs only in the substitution pattern.

  23. Electron-transporting foldable alternating copolymers of perylenediimide and flexible macromolecular chains 査読有り

    Tsuneaki Sakurai, Naomi Orito, Shusaku Nagano, Kenichi Kato, Masaki Takata, Shu Seki

    Materials Chemistry Frontiers 2 (4) 718-729 2018年

    DOI: 10.1039/c7qm00616k  

    eISSN:2052-1537

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    This journal is © The Royal Society of Chemistry and the Chinese Chemical Society 2018 Tuning the electrical conductivity of conjugated macromolecules by nanostructure ordering plays a key role in developing carrier transporting materials applicable to flexible organic electronic devices. Alternating copolymers of perylene-3,4,9,10-tetracarboxylic acid diimide (PDI) and flexible macromonomers, poly(dimethylsiloxane) (PDMS), poly(ethylene glycol) (PEG), or poly(propylene glycol) (PPG), were synthesized via simple polycondensation reactions between 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) and bis-amine-terminated corresponding macromonomers. Dynamic traces of absorption and fluorescence spectra of the series of alternating copolymers, with the indication of PDI chromophores, suggested the more foldable nature in tetrahydrofuran of the PDMS-based polymer than of the PEG- and PPG-based polymers. The folding capability of these polymers in solution was confirmed by fluorescence spectra and the absolute fluorescence quantum efficiency values. In the solid films, the condensed state of the polymers showed X-ray diffraction patterns of periodic structures, which depend on the type of macromolecular chains: PEG showed a highly crystallized state in contrast to the slightly crystalline PDI molecules in the PDMS and PPG-based polymers. Photoconductivity upon ultraviolet excitation has been screened by noncontact microwave measurements, and the mobility of electrons has also been characterized based on the kinetic traces of radical anions on the PDI chromophores. The negligible optical absorption observed from the PDMS-based polymers revealed the lowest photocarrier generation yield among the prepared polymers. The observed low conductivity for the PDMS-based, most foldable polymers possibly results from a lower photo-charge generation yield and thermal fluctuations of the flexible PDMS chains. The PEG-based polymer marked the largest electron mobility of 0.2 cm 2 V 1 s 1 , reflecting the highly crystalline nature of the PEG chains.

  24. Effect of Molecular Weight on Physical and Crystallization Properties of UHMW-poly [<i>(R)</i>-3-hydroxybutyrate-<i>co-(R)</i>-3-hydroxyhexanoate] 査読有り

    Taizo Kabe, Takashi Sugiura, Takaaki Hikima, Masaki Takata, Tadahisa Iwata

    Journal of Fiber Science and Technology 74 (1) 30-39 2018年

    出版者・発行元:Society of Fiber Science and Technology Japan

    DOI: 10.2115/fiberst.2018-0005  

    ISSN:0037-9875

    eISSN:2189-7654

  25. Donor/Acceptor Segregated π-Stacking Arrays by Use of Shish-Kebab-Type Polymeric Backbones: Highly Conductive Discotic Blends of Phthalocyaninatopolysiloxanes and Perylenediimides 査読有り

    Tsuneaki Sakurai, Satoru Yoneda, Shugo Sakaguchi, Kenichi Kato, Masaki Takata, Shu Seki

    Macromolecules 50 (23) 9265-9275 2017年12月12日

    DOI: 10.1021/acs.macromol.7b02020  

    ISSN:0024-9297

    eISSN:1520-5835

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    © 2017 American Chemical Society. Construction of large-area electron donor-acceptor (D-A) interfaces and hole/electron pathways is important for photoconducting and photovoltaic functions. Although blends of D- and A-type discotic π-systems have a possibility to realize one-dimensional charge carrier pathways as well as heterointerfaces, D-A segregated structures are difficult to develop by self-assembly because they are entropically unfavored structures. Here we report the use of shish-kebab-type hole-transporting discotic columns fixed by a self-threading polysiloxane chain and approach to such segregated nanostructures. Electron-donor/acceptor blends of soluble phthalocyaninatopolysiloxanes (Poly-SiPcs) and perylenedicarboximides (PDIs) were prepared, and their photoconductive property was investigated. Although Poly-SiPc1 shows a photoinduced charge separation with PDI1 analogous to the corresponding monomeric phthalocyanines (SiPc1 and H2Pc1), the Poly-SiPc1/PDI1 system displays a remarkably larger photoconductivity than SiPc1/PDI1 and H2Pc1/PDI1, which mostly results from the presence of hole-transporting pathways with the mobility μh,1D ∼ 0.1 cm2 V-1 s-1 in Poly-SiPc1 along the polysiloxane covalent bonds even upon mixing with PDI1. When π-stackable PDI2 is used instead of PDI1, X-ray diffraction analysis disclosed obvious signs of π-stacking periodicities for both Pc and PDI planes in the mixture, indicating the presence of donor-acceptor segregated domains of columnar structures. As a result, photoexcitation of Poly-SiPc1/PDI2 generates highly mobile holes and electrons, leading to the observation of a much larger conductivity.

  26. Optical and Structural Properties of ESIPT Inspired HBT-Fluorene Molecular Aggregates and Liquid Crystals 査読有り

    Vikas S. Padalkar, Yusuke Tsutsui, Tsuneaki Sakurai, Daisuke Sakamaki, Norimitsu Tohnai, Kenichi Kato, Masaki Takata, Tomoyuki Akutagawa, Ken Ichi Sakai, Shu Seki

    Journal of Physical Chemistry B 121 (45) 10407-10416 2017年11月16日

    DOI: 10.1021/acs.jpcb.7b08073  

    ISSN:1520-6106

    eISSN:1520-5207

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    © 2017 American Chemical Society. In bulk materials, positional isomers not only help in understanding how slight difference in molecular structure alters the crystal packing and optical properties, but also play a key role in developing new type of materials for functional applications. A detailed study on the photophysical properties of fluorene-HBT positional isomers in solution and in the solid state providing a molecular level understanding of the factors which influence fluorescence behavior is reported. Two molecules Ia and IIa were synthesized by Suzuki coupling reaction and their photophysical properties were compared to positional isomers Ib and IIb. Crystal structure analyses and density functional theory (DFT) computation studies were performed to understand structure-properties relation and the results reveal that changing substitution pattern has a marked influence on their packing modes and luminescence properties. Strong noncovalent interactions in the solid state hamper the excited state intramolecular proton transfer (ESIPT) process which causes fluorescence quenching in the solid state (Ia and IIa = φf, 28-40%; Ib and IIb = φf, 55-67%). Compounds show solvent-responsive and aggregation induced emission (AIE) properties. Bent structures of Ia with double and symmetric substitution of ESIPT motifs exhibit particularly unique condensed phase upon heating, confirmed as a nematic liquid crystalline phase, and this is the first report on the ESIPT and AIE active liquid crystalline materials with a banana-shaped molecule.

  27. Synthesis, properties and molecular conformation of paramylon ester derivatives 査読有り

    Hongyi Gan, Yukiko Enomoto, Taizo Kabe, Daisuke Ishii, Takaaki Hikima, Masaki Takata, Tadahisa Iwata

    Polymer Degradation and Stability 145 142-149 2017年11月

    DOI: 10.1016/j.polymdegradstab.2017.05.011  

    ISSN:0141-3910

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    © 2017 Elsevier Ltd Paramylon, which is a β-(1,3)-D-glucan photosynthesized by Euglena, was chemically modified by esterification. Various paramylon triesters with different alkyl chain lengths (carbon numbers 2–12) were successfully prepared. All of the paramylon triesters have higher thermal degradation temperatures than that of neat paramylon. Moreover, it was found that the paramylon triesters with C2–C6 alkyl chains are crystalline polymers with melting temperatures from 281 °C to 114 °C, and those with C8–C12 alkyl chains are amorphous polymers, confirmed by both DSC and X-ray diffraction analysis. Paramylon triesters with C3–C12 alkyl chains could shape self-sustaining films by both solvent-casting and melt-quench methods with high optical transmittance and sufficient tensile strength or elongation at break. Thermal and mechanical properties of paramylon triesters can be controlled freely from hard to soft by substituted acyl length. In the cases of the crystalline paramylon triesters, highly oriented and crystallized films could be fabricated by the thermally stretched method, and their tensile strengths have been obviously improved. Well-oriented X-ray fiber diagrams of the stretched and crystallized films suggest that all of the paramylon triesters have rare 5-fold helix conformation of molecular chains in crystal.

  28. Successive Dimensional Transition in (TMTTF)2PF6 Revealed by Synchrotron X-ray Diffraction 査読有り

    Shunsuke Kitou, Tatsuya Fujii, Tadashi Kawamoto, Naoyuki Katayama, Sachiko Maki, Eiji Nishibori, Kunihisa Sugimoto, Masaki Takata, Toshikazu Nakamura, Hiroshi Sawa

    Physical Review Letters 119 (6) 2017年8月7日

    DOI: 10.1103/PhysRevLett.119.065701  

    ISSN:0031-9007

    eISSN:1079-7114

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    © 2017 American Physical Society. A quasi-one-dimensional organic charge-transfer salt (TMTTF)2PF6 undergoes a multistep phase transition as the temperature decreases. One of these transitions is called a "structureless transition," and these detailed structures were unknown for many years. With synchrotron x-ray diffraction, we observed a slight structural difference owing to the effect of charge-order transition between two TMTTF molecules in a dimer, which corresponds to the charge transfer δCO=0.20e. The two-dimensional Wigner crystallization was determined from an electron density analysis using core differential Fourier synthesis. Furthermore, we found that the ground state due to tetramerization, called the spin Peierls phase, is a three-dimensional transition with interchain correlation.

  29. Effect of monomeric composition on the thermal, mechanical and crystalline properties of poly[(R)-lactate-co-(R)-3-hydroxybutyrate] 査読有り

    Daisuke Ishii, Kenji Takisawa, Ken'ichiro Matsumoto, Toshihiko Ooi, Takaaki Hikima, Masaki Takata, Seiichi Taguchi, Tadahisa Iwata

    Polymer 122 169-173 2017年7月28日

    DOI: 10.1016/j.polymer.2017.06.039  

    ISSN:0032-3861

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    © 2017 Elsevier Ltd Poly[(R)-lactate-co-(R)-3-hydroxybutyrate] [P(LA-co-3HB)] is a biobased polyester with flexible properties efficiently synthesized by engineered Escherichia coli. Here, we aimed at optimizing the monomeric composition of the copolymer in terms of its flexibility, and elucidating structural features contributing to their mechanical properties. The LA fraction was successfully regulated in the range of 6–66 mol% by combination of metabolic and enzyme engineering approaches. The copolymers with higher LA fraction showed decreasing melting point from 160 to 125 °C, but increasing glass transition temperature from 7 to 27 °C. Crystallinity of the as-cast film, that was mainly attributed to the crystallization of 3HB unit, also decreased with the increasing LA fraction. Owing to the combined effect of these parameters, the highest elongation to break (approximately 400%), which is comparable to that of polyethylene, was obtained for the copolymers with middle range LA fraction (33 mol%). The high flexibility was maintained in most of the copolymers. Notably, P(21mol%LA-co-3HB) retained its high elongation at break (about 300%) even after storage under ambient condition for 5 months. These results demonstrate that introduction of LA units into the polymer chain effectively and stably inhibited the crystallization of 3HB units.

  30. Enhanced ferromagnetic transition temperature induced by a microscopic structural rearrangement in the diluted magnetic semiconductor Ge1−xMnxTe 査読有り

    M. Kriener, T. Nakajima, Y. Kaneko, A. Kikkawa, D. Hashizume, K. Kato, M. Takata, T. Arima, Y. Tokura, Y. Taguchi

    Physical Review B 95 224418 2017年6月15日

    出版者・発行元:American Physical Society (APS)

    DOI: 10.1103/physrevb.95.224418  

    ISSN:2469-9950

    eISSN:2469-9969

  31. Visualization of Individual Images in Patterned Organic-Inorganic Multilayers Using GISAXS-CT 査読有り

    Hiroki Ogawa, Yukihiro Nishikawa, Mikihito Takenaka, Akihiko Fujiwara, Yohei Nakanishi, Yoshinobu Tsujii, Masaki Takata, Toshiji Kanaya

    Langmuir 33 (19) 4675-4681 2017年5月16日

    DOI: 10.1021/acs.langmuir.7b00691  

    ISSN:0743-7463

    eISSN:1520-5827

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    © 2017 American Chemical Society. Using grazing-incidence small-angle scattering (GISAXS) with computed tomography (CT), we have individually reconstructed the spatial distribution of a thin gold (Au) layer buried under a thin poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) layer. Owing to the difference between total reflection angles of Au and PS-b-P2VP, the scattering profiles for Au nanoparticles and self-assembled nanostructures of PS-b-P2VP could be independently obtained by changing the X-ray angle of incidence. Reconstruction of scattering profiles allows one to separately characterize spatial distributions in Au and PS-b-P2VP nanostructures.

  32. Detailed Structural Analysis of a Self-Assembled Vesicular Amphiphilic NCN-Pincer Palladium Complex by Using Wide-Angle X-Ray Scattering and Molecular Dynamics Calculations 査読有り

    Go Hamasaka, Tsubasa Muto, Yoshimichi Andoh, Kazushi Fujimoto, Kenichi Kato, Masaki Takata, Susumu Okazaki, Yasuhiro Uozumi

    Chemistry - A European Journal 23 (6) 1291-1298 2017年1月26日

    DOI: 10.1002/chem.201603494  

    ISSN:0947-6539

    eISSN:1521-3765

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    © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Wide-angle X-ray scattering experiments and all-atomistic molecular dynamics calculations were performed to elucidate the detailed structure of bilayer vesicles constructed by self-assembly of an amphiphilic palladium NCN-pincer complex. We found an excellent agreement between the experimental and calculated X-ray spectra, and between the membrane thickness determined from a TEM image and that calculated from an electron-density profile, which indicated that the calculated structure was highly reliable. The analysis of the simulated bilayer structure showed that in general the membrane was softer than other phospholipid bilayer membranes. In this bilayer assemblage, the degree of alignment of complex molecules in the bilayer membrane was quite low. An analysis of the electron-density profile shows that the bilayer assemblage contains a space through which organic molecules can exit. Furthermore, the catalytically active center is near this space and is easily accessible by organic molecules, which permits the bilayer membrane to act as a nanoreactor. The free energy of permeation of water through the bilayer membrane of the amphiphilic complex was 12 kJ mol−1, which is much lower than that for phospholipid bilayer membranes in general. Organic molecules are expected to pass though the bilayer membrane. The self-assembled vesicles were shown to be catalytically active in a Miyaura–Michael reaction in water.

  33. First-Principles Calculation, Synthesis, and Catalytic Properties of Rh-Cu Alloy Nanoparticles 査読有り

    Tokutaro Komatsu, Hirokazu Kobayashi, Kohei Kusada, Yoshiki Kubota, Masaki Takata, Tomokazu Yamamoto, Syo Matsumura, Katsutoshi Sato, Katsutoshi Nagaoka, Hiroshi Kitagawa

    Chemistry - A European Journal 23 (1) 57-60 2017年1月1日

    DOI: 10.1002/chem.201604286  

    ISSN:0947-6539

    eISSN:1521-3765

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    © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim The first synthesis of pure Rh1−xCux solid-solution nanoparticles is reported. In contrast to the bulk state, the solid-solution phase was stable up to 750 °C. Based on facile density-functional calculations, we made a prediction that the catalytic activity of Rh1−xCux can be maintained even with 50 at % replacement of Rh with Cu. The prediction was confirmed for the catalytic activities on CO and NOx conversions.

  34. Material deformation by using new 3GeV synchrotron light source

    Tadashi Abukawa, Wataru Yashiro, Takeo Ejima, Masashi Watanabe, Nobuyuki Nishimori, Sadao Miura, Hiroyuki Hama, Masaki Takata

    Proceedings of the International Display Workshops 1 584-586 2017年

    ISSN:1883-2490

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    © 2017 Proceedings of the International Display Workshops. All rights reserved. Synchrotron Radiation (SR) facilities around the world have been recognized as premier research tool for Nano Technology as well as industrial application including display device technology. A SR facility, Synchrotron Light in Tohoku, Japan (SLiT-J), has been projected since 2011. Current status and perspectives are being presented.

  35. Observation of constraint surface dynamics of polystyrene thin films by functionalization of a silsesquioxane cage 査読有り

    Taiki Hoshino, Shiki Nojima, Masanao Sato, Tomoyasu Hirai, Yuji Higaki, So Fujinami, Daiki Murakami, Shigesaburo Ogawa, Hiroshi Jinnai, Atsushi Takahara, Masaki Takata

    Polymer 105 487-499 2016年11月22日

    DOI: 10.1016/j.polymer.2016.08.040  

    ISSN:0032-3861

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    © 2016 Elsevier Ltd The surface dynamics of polyhedral oligomeric silsesquioxane (POSS)-functionalized polystyrene (PS-POSS) thin films above the glass transition temperature were studied by grazing-incidence X-ray photon correlation spectroscopy in order to elucidate the effects of POSS at the end of the polystyrene chains. Much slower fluctuations were observed in the surface of PS-POSS thin films than in the polystyrene thin films, despite the negligible difference in their bulk viscosity. Quantitative analysis based on fluctuation-dissipation theorem indicated that there is a high-viscosity layer at the surface of the PS-POSS films, and that the substrate interface originated from POSS segregation.

  36. Regulation of NO uptake in flexible Ru dimer chain compounds with highly electron donating dopants 査読有り

    Jun Zhang, Wataru Kosaka, Hiroki Fukunaga, Susumu Kitagawa, Masaki Takata, Hitoshi Miyasaka

    Inorganic Chemistry 55 (22) 12085-12092 2016年11月21日

    DOI: 10.1021/acs.inorgchem.6b02349  

    ISSN:0020-1669

    eISSN:1520-510X

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    © 2016 American Chemical Society. On-demand design of porous frameworks for selective capture of specific gas molecules, including toxic gas molecules such as nitric oxide (NO), is a very important theme in the research field of molecular porous materials. Herein, we report the achievement of highly selective NO adsorption through chemical doping in a framework (i.e., solid solution approach): the highly electron donating unit [Ru2(o-OMePhCO2)4] (o-OMePhCO2- = o-anisate) was transplanted into the structurally flexible chain framework [Ru2(4-Cl-2-OMePhCO2)4(phz)] (0; 4-Cl-2-OMePhCO2- = 4-chloro-o-anisate and phz = phenazine) to obtain a series of doped compounds, [{Ru2(4-Cl-2-OMePhCO2)4}1-x{Ru2(o-OMePhCO2)4}x(phz)] (x = 0.34, 0.44, 0.52, 0.70, 0.81, 0.87), with [Ru2(o-OMePhCO2)4(phz)] (1) as x = 1. The original compound 1 was made purely from a "highly electron donating unit" but had no adsorption capability for gases because of its nonporosity. Meanwhile, the partial transplant of the electronically advantageous [Ru2(o-OMePhCO2)4] unit with x = 0.34-0.52 in 0 successfully enhanced the selective adsorption capability of NO in an identical structurally flexible framework; an uptake at 95 kPa that was 1.7-3 mol/[Ru2] unit higher than that of the original 0 compound was achieved (121 K). The solid solution approach is an efficient means of designing purposeful porous frameworks.

  37. 放射光が拓く高分子材料の可視化技術

    高田 昌樹

    高分子 65 (11) 626-627 2016年11月

  38. Thermodynamically Anchoring-Frustrated Surface to Trigger Bulk Discontinuous Orientational Transition 査読有り

    Satoshi Aya, Yuji Sasaki, Hideo Takezoe, Ken Ishikawa, Kenji Ema, Takaaki Hikima, Masaki Takata, Fumito Araoka

    Langmuir 32 (41) 10545-10550 2016年10月18日

    DOI: 10.1021/acs.langmuir.6b03112  

    ISSN:0743-7463

    eISSN:1520-5827

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    © 2016 American Chemical Society. Surface-specific liquid crystal (LC) nanostructures provide a unique platform for studying surface-wetting phenomena and also for technological applications. The most important studies on LC properties are related to bulk alignment, surface anchoring, and so on. Here, we study an LC system with a nematic liquid crystal (NLC) on a perfluoropolymer-coated substrate, in which a discontinuous bulk orientational transition has recently been found. Using free-energy analysis based on experimental results of the newly-conducted grazing-incidence X-ray diffraction (GI-XRD) measurements, we have confirmed a thermodynamic growth process of smectic liquid crystalline wetting nanosheets on the surface and successfully explained that a frustrated surface of planar and vertical anchoring states accompanied by an elastic energy cost kinetically triggers the bulk reorientation in the first-order manner. This interfacial bottom-up process may offer a general insight into how interfacial hierarchical molecular architectures alter the bulk properties of matter thermodynamically.

  39. Co-crystallization phenomena in biosynthesized isotactic poly[(R)-lactate-co-(R)-2-hydroxybutyrate]s with various lactate unit ratios 査読有り

    Taizo Kabe, Ken'ichiro Matsumoto, Satsuki Terai, Takaaki Hikima, Masaki Takata, Masahiro Miyake, Seiichi Taguchi, Tadahisa Iwata

    Polymer Degradation and Stability 132 137-144 2016年10月1日

    DOI: 10.1016/j.polymdegradstab.2016.03.005  

    ISSN:0141-3910

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    © 2016 Elsevier Ltd Poly[(R)-lactate-co-(R)-2-hydroxybutyrate], which is biosynthesized as a random co-polyester by microbial organisms, with various ratios of lactic acid (LA) to hydroxybutyrate monomers has been isothermally crystallized to investigate its thermal properties and crystal structure changes. Differential scanning calorimetry on the isothermally crystallized samples detected endothermic peaks due to the melting of the crystals at all LA unit ratios. Melting temperatures of the copolymers increased from ca. 107 °C–146 °C as the LA unit ratio increased. Glass transition temperatures also increased from 24 °C to 44 °C with increasing LA unit ratio. A melting temperature was observed even at LA unit ratios around 50%. Wide-angle X-ray measurements also revealed that co-crystallization occurred at all samples, including at LA unit ratios of ca. 50%. Despite of “jumping” phenomena many co-crystallizable random copolymers having, the lattice constants changed “linearly” from resembling poly[(R)-lactate] to poly[(R)-2-hydroxybutyrate] depending on the LA unit ratio. This unique co-crystallization behavior is discussed in detail.

  40. Supramolecular Scaffold for Tailoring the Two-Dimensional Assembly of Functional Molecular Units into Organic Thin Films 査読有り

    Franco King Chi Leung, Fumitaka Ishiwari, Takashi Kajitani, Yoshiaki Shoji, Takaaki Hikima, Masaki Takata, Akinori Saeki, Shu Seki, Yoichi M.A. Yamada, Takanori Fukushima

    Journal of the American Chemical Society 138 (36) 11727-11733 2016年9月14日

    DOI: 10.1021/jacs.6b05513  

    ISSN:0002-7863

    eISSN:1520-5126

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    © 2016 American Chemical Society. Tailoring structurally anisotropic molecular assemblies while controlling their orientation on solid substrates is an important subject for advanced technologies that use organic thin films. Here we report a supramolecular scaffold based on tripodal triptycene assemblies, which enables functional molecular units to assemble into a highly oriented, multilayered two-dimensional (2D) structure on solid substrates. The triptycene building block carries an ethynyl group and three flexible side chains at the 10- and 1,8,13-positions, respectively. These bridgehead-substituted tripodal triptycenes self-assembled on solid substrates to form a well-defined "2D hexagonal + 1D lamellar" structure, which developed parallel to the surface of the substrates. Remarkably, the assembling properties of the triptycene building blocks, particularly for a derivative with tri(oxyethylene)-containing side chains, were not impaired when the alkyne terminal was functionalized with a large molecular unit such as C60, which is comparable in diameter to the triptycene framework. Consequently, thin films with a multilayered 2D assembly of the C60 unit were obtained. Flash-photolysis time-resolved microwave conductivity (FP-TRMC) measurements revealed that the C60 film exhibits highly anisotropic charge-transport properties. Bridgehead-substituted tripodal triptycenes may provide a versatile supramolecular scaffold for tailoring the 2D assembly of molecular units into a highly oriented thin film, and in turn for exploiting the full potential of anisotropic molecular functions.

  41. Upgrade of beamline BL25SU for soft x-ray imaging and spectroscopy of solid using nano- and micro-focused beams at SPring-8 査読有り

    Yasunori Senba, Haruhiko Ohashi, Yoshinori Kotani, Tetsuya Nakamura, Takayuki Muro, Takuo Ohkochi, Naruki Tsuji, Hikaru Kishimoto, Takanori Miura, Masayuki Tanaka, Masahiro Higashiyama, Sunao Takahashi, Yasuhide Ishizawa, Tomohiro Matsushita, Yukito Furukawa, Toru Ohata, Nobuteru Nariyama, Kunikazu Takeshita, Toyohiko Kinoshita, Akihiko Fujiwara, Masaki Takata, Shunji Goto

    AIP Conference Proceedings 1741 030044 2016年7月27日

    DOI: 10.1063/1.4952867  

    ISSN:0094-243X

    eISSN:1551-7616

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    © 2016 Author(s). Substantial upgrades have been made to the beamline BL25SU at SPring-8 for soft X-ray imaging and spectroscopy of solid-state materials. The upgraded beamline consists of two branches: a micro-beam branch with high energy resolution, and a nano-beam branch with small angular divergence. The beamline has been available for use since October 2014, following a half year commissioning period. We present here the beamline performance parameters, including resolving power, photon flux, and focused beam size, which are consistent with designed specifications.

  42. Effect of Cholesterol on the Interaction of Cytochrome P450 Substrate Drug Chlorzoxazone with the Phosphatidylcholine Bilayer 査読有り

    Ayumi Yamada, Nobutaka Shimizu, Takaaki Hikima, Masaki Takata, Toshihide Kobayashi, Hiroshi Takahashi

    Biochemistry 55 (28) 3888-3898 2016年7月19日

    DOI: 10.1021/acs.biochem.6b00286  

    ISSN:0006-2960

    eISSN:1520-4995

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    © 2016 American Chemical Society. Many drugs are oxidized by membrane protein cytochrome P450 (CYP) enzymes during their metabolism process. CYPs are located mainly in endoplasmic reticulum (ER) membranes. Recent studies have suggested that CYP substrate drugs first bind the lipid bilayers of ER membranes and then the drugs reach the active site of CYP by way of an access channel. The entrance of the channel is located in the hydrophobic regions of the lipid bilayers. One of the features of the ER membrane is a cholesterol content that is lower than those of other biomembranes. In this study, the cholesterol concentration dependence of the interaction of a CYP substrate drug, chlorzoxazone (CZX), with model membranes composed of phosphatidylcholine (PC) and cholesterol was examined via differential scanning calorimetry (DSC), UV-visible spectroscopy, and X-ray diffraction. Experimental results indicated that CZX can bind to pure PC bilayers in the absence of cholesterol and that, by contrast, a high cholesterol concentration (30-50 mol %) tends to prevent CZX from binding to PC bilayers. Interestingly, the effect of cholesterol on the binding and insertion of CZX was biphasic. In the case of palmitoyloleoylphosphatidylcholine (POPC) bilayers containing 5-10 mol % cholesterol, the CZX's binding and penetration into the bilayer were found to be greater than those with pure POPC bilayers. The concentration of 5-10 mol % nearly corresponds to the cholesterol concentration of ER membranes. The low cholesterol contents (12-20 mol %) of ER membranes might be the most suitable for the CYP drug metabolism process in ER membranes.

  43. Investigating thermal properties of and melting-induced structural changes in cold-drawn P(3HB) films with α- And β-structures using real-time X-ray measurements and high-speed DSC 査読有り

    Taizo Kabe, Toshihisa Tanaka, Hironori Marubayashi, Takaaki Hikima, Masaki Takata, Tadahisa Iwata

    Polymer 93 181-188 2016年6月14日

    DOI: 10.1016/j.polymer.2016.04.028  

    ISSN:0032-3861

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    © 2016 Elsevier Ltd. All rights reserved. In this study, we prepared two types of drawn films of poly[(R)-3-hydroxybutyrate], a microbial polyester: those containing only α-crystals and those containing both α- and β-crystals. Real-time wide-angle X-ray diffraction (WAXD) and real-time small-angle X-ray scattering (SAXS) measurements were performed during heating using synchrotron X-rays, along with high-speed differential scanning calorimetry (DSC), to measure the melting temperature of the β-crystals, which were present in a small amount. The changes induced in the highly ordered structure of the films were also observed. Based on the results of the real-time WAXD measurements, the melting temperature of the β-crystals was found to vary from 90 °C to 130 °C. The results of high-speed DSC supported these results. The real-time SAXS measurements allowed the changes in the highly order structure of the films to be observed. A model to explain the changes in the highly order structure is constructed based on the obtained results.

  44. Superionic Conduction in Co-Vacant P2-Na<inf>x</inf>CoO<inf>2</inf> Created by Hydrogen Reductive Elimination 査読有り

    Kenichi Kato, Hidetaka Kasai, Akihiro Hori, Masaki Takata, Hiroshi Tanaka, Susumu Kitagawa, Akira Kobayashi, Nobuki Ozawa, Momoji Kubo, Hidekazu Arikawa, Tatsuya Takeguchi, Masaaki Sadakiyo, Miho Yamauchi

    Chemistry - An Asian Journal 11 (10) 1537-1541 2016年5月20日

    DOI: 10.1002/asia.201600370  

    ISSN:1861-4728

    eISSN:1861-471X

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    © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. The layered P2-NaxMO2 (M: transition metal) system has been widely recognized as electronic or mixed conductor. Here, we demonstrate that Co vacancies in P2-NaxCoO2 created by hydrogen reductive elimination lead to an ionic conductivity of 0.045 S cm-1 at 25 °C. Using in situ synchrotron X-ray powder diffraction and Raman spectroscopy, the composition of the superionic conduction phase is evaluated to be Na0.61(H3O)0.18Co0.93O2. Electromotive force measurements as well as molecular dynamics simulations indicate that the ion conducting species is proton rather than hydroxide ion. The fact that the Co-stoichiometric compound Nax(H3O)yCoO2 does not exhibit any significant ionic conductivity proves that Co vacancies are essential for the occurrence of superionic conductivity. Migration routes: Nax(H3O)yCo1-δO2 obtained by hydrogen reductive elimination has been found to exhibit superionic conductivity at room temperature. Disordered structures observed at the Na sites 1 and 3 imply the diffusion channels of conducting ion species. In molecular dynamics simulations using the experimental model, H and O delivered from H3O appear to migrate between the sites 2 and 3 and 1 and 2, respectively, forming a double honeycombed sublattice.

  45. Crystal Polymorphism of Curdlan Propionate: 6-Fold versus 5-Fold Helices 査読有り

    Hironori Marubayashi, Kazuyori Yukinaka, Yukiko Enomoto-Rogers, Takaaki Hikima, Masaki Takata, Tadahisa Iwata

    ACS Macro Letters 5 (5) 607-611 2016年5月17日

    DOI: 10.1021/acsmacrolett.6b00186  

    eISSN:2161-1653

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    © 2016 American Chemical Society. The molecular and crystal structures of curdlan propionate (CDPr) were examined by the X-ray fiber diffraction methods combined with energy calculations. CDPr forms two different crystal structures (CDPr forms I and II) depending on annealing conditions: solvent-annealing yields CDPr form I, whereas thermal-annealing gives CDPr form II. In CDPr form I, the 6/1 helix is packed in the hexagonal unit cell with a = b = 1.154 nm, and c (fiber axis) = 2.287 nm. In the case of CDPr form II, the 5/1 helix is packed in the pseudohexagonal cell with a = b = 1.175 nm, and c (fiber axis) = 1.859 nm. The crystal transition from CDPr forms I to II occurs by thermal-annealing at temperatures ≥ 160 °C.

  46. Heat-treatment-induced switching of magnetic states in the doped polar semiconductor Ge<inf>1-x</inf>Mn<inf>x</inf>Te 査読有り

    M. Kriener, T. Nakajima, Y. Kaneko, A. Kikkawa, X. Z. Yu, N. Endo, K. Kato, M. Takata, T. Arima, Y. Tokura, Y. Taguchi

    Scientific Reports 6 2016年5月10日

    DOI: 10.1038/srep25748  

    eISSN:2045-2322

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    Cross-control of a material property - manipulation of a physical quantity (e.g., magnetisation) by a nonconjugate field (e.g., electrical field) - is a challenge in fundamental science and also important for technological device applications. It has been demonstrated that magnetic properties can be controlled by electrical and optical stimuli in various magnets. Here we find that heat-treatment allows the control over two competing magnetic phases in the Mn-doped polar semiconductor GeTe. The onset temperatures T c of ferromagnetism vary at low Mn concentrations by a factor of five to six with a maximum Tc ≈ 180 K, depending on the selected phase. Analyses in terms of synchrotron x-ray diffraction and energy dispersive x-ray spectroscopy indicate a possible segregation of the Mn ions, which is responsible for the high-T c phase. More importantly, we demonstrate that the two states can be switched back and forth repeatedly from either phase by changing the heat-treatment of a sample, thereby confirming magnetic phase-change-memory functionality.

  47. Direct Observation on Spin-Coating Process of PS-b-P2VP Thin Films 査読有り

    Hiroki Ogawa, Mikihito Takenaka, Tsukasa Miyazaki, Akihiko Fujiwara, Byeongdu Lee, Keisuke Shimokita, Eiji Nishibori, Masaki Takata

    Macromolecules 49 (9) 3471-3477 2016年5月10日

    DOI: 10.1021/acs.macromol.6b00049  

    ISSN:0024-9297

    eISSN:1520-5835

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    © 2016 American Chemical Society. We studied the structural development of symmetric poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) block copolymers during spin-coating using in situ grazing incidence small-angle X-ray scattering (GISAXS) measurements. During the spin-coating process, after the formation of the micelles in dilute solution, the selective solvent induced two kinds of the morphological transition. First, the disordered spherical micelles were transformed into a BCC lattice of spheres of which the (110) plane was oriented perpendicularly to the substrate surface. Second, further evaporation induced a transition from spheres on the BCC lattice into cylindrical structures. The orientation of the cylinders perpendicular to the substrate surface was induced by solvent convection perpendicular to the substrate, which occurs during rapid solvent evaporation. After this transition, vitrification of PS and P2VP prevented any further transition from cylinders to the more thermodynamically stable lamellar structures, as are generally observed as the bulk equilibrium state.

  48. Inside Cover: Superionic Conduction in Co-Vacant P2-NaxCoO2 Created by Hydrogen Reductive Elimination (Chem. Asian J. 10/2016) 査読有り

    Kenichi Kato, Hidetaka Kasai, Akihiro Hori, Masaki Takata, Hiroshi Tanaka, Susumu Kitagawa, Akira Kobayashi, Nobuki Ozawa, Momoji Kubo, Hidekazu Arikawa, Tatsuya Takeguchi, Masaaki Sadakiyo, Miho Yamauchi

    Chemistry – An Asian Journal 11 (10) 1465 2016年5月

    DOI: 10.1002/asia.201600589  

  49. SPring-8 BL36XU: Catalytic Reaction Dynamics for Fuel Cells 査読有り

    O Sekizawa, T Uruga, Y Takagi, K Nitta, K Kato, H Tanida, K Uesugi, M Hoshino, E Ikenaga, K Takeshita, S Takahashi, M Sano, H Aoyagi, A Watanabe, N Nariyama, H Ohashi, H Yumoto, T Koyama, Y Senba, T Takeuchi, Y Furukawa, T Ohata, T Matsushita, Y Ishizawa, T Kudo, H Kimura, H Yamazaki, T Tanaka, T Bizen, T Seike, S Goto, H Ohno, M Takata, H Kitamura, T Ishikawa, M Tada, T Yokoyama, Y Iwasawa

    Journal of Physics: Conference Series 712 012142-012142 2016年5月

    出版者・発行元:IOP Publishing

    DOI: 10.1088/1742-6596/712/1/012142  

    ISSN:1742-6588

    eISSN:1742-6596

  50. Crystalline coordination framework endowed with dynamic gate-opening behaviour by being downsized to a thin film 査読有り

    Shun Sakaida, Kazuya Otsubo, Osami Sakata, Chulho Song, Akihiko Fujiwara, Masaki Takata, Hiroshi Kitagawa

    Nature Chemistry 8 (4) 377-383 2016年4月

    DOI: 10.1038/nchem.2469  

    ISSN:1755-4330

    eISSN:1755-4349

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    © 2016 Macmillan Publishers Limited. All rights reserved. The fabrication of porous coordination frameworks in thin-film forms has been investigated intensively with a view to using their structural response to external stimuli and guests for potential nanotechnological applications, for example as membranes for gas separation. Here we report a coordination framework that exhibits a dynamic guest-sorption behaviour in a nanometre-sized thin-film form (16 nm thick), yet shows no guest uptake in the bulk. Highly oriented crystalline thin films of this coordination framework - which consists of interdigitated two-dimensional layers of {Fe(py)2[Pt(CN)4]} (py, pyridine) - were fabricated through liquid-phase layer-by-layer synthesis. The resulting thin film exhibited a clear guest uptake with a structural transformation of the gate-opening type as characterized by in situ X-ray diffraction. Increasing the film's thickness markedly suppressed this behaviour. We envisage that such a crystal-downsizing effect may be observed with other coordination frameworks, and may be of use to develop functional materials, for example, for switching or sensing devices.

  51. An Adsorbate Discriminatory Gate Effect in a Flexible Porous Coordination Polymer for Selective Adsorption of CO2 over C2H2 査読有り

    Maw Lin Foo, Ryotaro Matsuda, Yuh Hijikata, Rajamani Krishna, Hiroshi Sato, Satoshi Horike, Akihiro Hori, Jingui Duan, Yohei Sato, Yoshiki Kubota, Masaki Takata, Susumu Kitagawa

    Journal of the American Chemical Society 138 (9) 3022-3030 2016年3月9日

    DOI: 10.1021/jacs.5b10491  

    ISSN:0002-7863

    eISSN:1520-5126

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    © 2016 American Chemical Society. The adsorptive separation of C2H2 and CO2 via porous materials is nontrivial due to the close similarities of their boiling points and kinetic diameters. In this work, we describe a new flexible porous coordination polymer (PCP) [Mn(bdc)(dpe)] (H2bdc = 1,4-benzenedicarboxylic acid, dpe = 1,2-di(4-pyridyl)ethylene) having zero-dimensional pores, which shows an adsorbate discriminatory gate effect. The compound shows gate opening type abrupt adsorption for C2H2 but not for CO2, leading to an appreciable selective adsorption of CO2 over C2H2 at near ambient temperature (273 K). The origin of this unique selectivity, as unveiled by in situ adsorption-X-ray diffraction experiments and density functional theory calculations, is due to vastly different orientations between the phenylene ring of bdc and each gas in the nanopores. The structural change by photochemical transformation of this PCP via [2 + 2] photodimerization leads to the removal of inverse CO2/C2H2 selectivity, verifying the mechanism of the guest discriminatory gate effect.

  52. Orthorhombic distortion and orbital order in the vanadium spinel FeV2 O4 査読有り

    S. Kawaguchi, H. Ishibashi, S. Nishihara, S. Mori, J. Campo, F. Porcher, O. Fabelo, K. Sugimoto, J. Kim, K. Kato, M. Takata, H. Nakao, Y. Kubota

    Physical Review B 93 (2) 2016年1月13日

    DOI: 10.1103/PhysRevB.93.024108  

    ISSN:2469-9950

    eISSN:2469-9969

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    © 2016 American Physical Society. Using synchrotron and neutron diffraction measurements, we find a low-temperature orthorhombic phase in vanadium spinel FeV2O4. The orbital order of V3+ ions with tetragonal normal modes occurs at 68 K, and this leads to an appearance of the pseudotetragonal phase at a noncollinear ferrimagnetic transition temperature. Below the magnetic transition temperature, unconventional behavior of the orbital state of Fe2+ ions accompanied by the emergence of the orthorhombic phase was observed by using the normal mode analysis. We have also studied the structural properties of orbitally diluted materials. The orthorhombic phase, which is significantly affected by the other ions, is intrinsic in FeV2O4. We suggest the orthorhombic phase is strongly related with the double orbital states of Fe2+ and V3+ ions.

  53. 21aCC-8 構造解析から見たGe_<1-x>Mn_xTeの強磁性転移温度T_cの増大の起源

    クリーナー M., 中島 多朗, 金子 良夫, 吉川 明子, 橋爪 大輔, 加藤 健一, 高田 昌樹, 有馬 孝尚, 田口 康二郎, 十倉 好紀

    日本物理学会講演概要集 71 1239-1239 2016年

    出版者・発行元:一般社団法人日本物理学会

    DOI: 10.11316/jpsgaiyo.71.1.0_1239  

    ISSN:2189-079X

  54. 19pAQ-5 単結晶X線回折実験におけるマルチドメインを持つLaTiO_3の精密構造解析手法の開発

    菅原 健人, 樋口 貴文, 澤 博, 杉本 邦久, 高田 昌樹, 有馬 孝尚, 田口 康二郎, 十倉 好紀

    日本物理学会講演概要集 71 2673-2673 2016年

    出版者・発行元:一般社団法人日本物理学会

    DOI: 10.11316/jpsgaiyo.71.1.0_2673  

    ISSN:2189-079X

  55. Epitaxy-driven nanostructure formation in polymer blend thin films containing regioregular poly(3-hexylthiophene) 査読有り

    Hirotaka Ejima, Kazuhiro Ogita, Midori Yamamoto, Sono Sasaki, Takaaki Hikima, Masaki Takata, Naoko Yoshie

    Chemistry Letters 45 (6) 604-606 2016年

    DOI: 10.1246/cl.160068  

    ISSN:0366-7022

    eISSN:1348-0715

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    © 2016 The Chemical Society of Japan. Epitaxial crystallization onto a directionally crystallizable organic solvent, 1,3,5-trichlorobenzene, was applied to polymer blends containing regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) and either polystyrene (PS) or regiorandom poly(3-dodecylthiophene-2,5-diyl) (P3DDT). Well-ordered lamellae-inlamella and dots-in-lamella structures were observed for P3HT/PS and P3HT/P3DDT, respectively. P3HT/PS gave more-discernible lamellar nanopatterns than did P3HT/P3DDT, owing to miscibility differences. Grazing-incidence wide-angle X-ray diffraction analysis, and polarized UV-visible absorption spectroscopy revealed that the P3HT crystalline lamellae were oriented edge-on in the thin films. Polymer blend nanostructures were also obtained when a third component, phenyl-C61-butyric acid methyl ester, was present, thus demonstrating the potential of this strategy for engineering the nanostructure of the active layers in P3HT-based electronic devices.

  56. A new approach for the facile preparation of metal-organic framework composites directly contacting with metal nanoparticles through arc plasma deposition 査読有り

    Masaaki Sadakiyo, Shotaro Yoshimaru, Hidetaka Kasai, Kenichi Kato, Masaki Takata, Miho Yamauchi

    Chemical Communications 52 (54) 8385-8388 2016年

    DOI: 10.1039/c6cc02729f  

    ISSN:1359-7345

    eISSN:1364-548X

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    © The Royal Society of Chemistry 2016. The arc plasma deposition (APD) method is first applied to prepare metal-organic framework (MOF) composites loading metal nanoparticles having a direct contact with the MOF. We demonstrate the detailed growth mechanism of metal particles on the MOFs and the applicability of the APD for various combinations of metals and MOFs.

  57. Preferential formation of columnar mesophases via peripheral modification of discotic π-systems with immiscible side chain pairs 査読有り

    Tsuneaki Sakurai, Yusuke Tsutsui, Kenichi Kato, Masaki Takata, Shu Seki

    Journal of Materials Chemistry C 4 (7) 1490-1496 2016年

    DOI: 10.1039/c6tc00021e  

    ISSN:2050-7534

    eISSN:2050-7526

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    © The Royal Society of Chemistry 2016. When sufficient volume of dodecyl chains are attached at one imide position of a perylenediimide (PDI) or naphthalenediimide (NDI) core and triethyleneglycol (TEG) chains on the other side, the resulting molecules PDIC12/TEGG0, PDIC12/TEGG1, and NDIC12/TEGG0 self-assemble into a rectangular columnar mesophase with p2mg symmetry, forming hydrophobic/hydrophilic nano-segregation of side chains. The driving force of PDIC12/TEGG0 to form preferentially the rectangular columnar mesophase is given by the immiscibility between the side chain pairs - exclusion of other phases such as cubic, crystalline and amorphous phases, where thermodynamically unstable contacts between hydrophobic and hydrophilic chains considerably take place. In contrast, this preference is less found in the analogous molecules decorated with either dodecyl or TEG chains at both termini. PDIC12/C12G0 and PDITEG/TEGG0 form a hexagonal columnar mesophase because of the optimized chain/core volume. However, if the side chain volume grows, PDITEG/TEGG1 does not form a mesophase but undergoes a soft crystalline-isotropic phase transition, while PDIC12/C12G1 was revealed to destabilize its columnar mesophase but forms a micellar cubic phase. NDIC12/C12G0 resulted in a strong crystallization, while NDITEG/TEGG0 formed amorphous liquid. The molecular design strategy using immiscible side chain pairs potentially enables a variety of π-systems to stack up to form a columnar phase rather than other ordered phases, regardless of the chain/core volume balance.

  58. A significant change in selective adsorption behaviour for ethanol by flexibility control through the type of central metals in a metal-organic framework 査読有り

    Masaaki Sadakiyo, Teppei Yamada, Kenichi Kato, Masaki Takata, Hiroshi Kitagawa

    Chemical Science 7 (2) 1349-1356 2016年

    DOI: 10.1039/c5sc03325j  

    ISSN:2041-6520

    eISSN:2041-6539

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    © 2016 The Royal Society of Chemistry. Closed-open structural transformations in flexible metal-organic frameworks (MOFs) are of interest for potential applications such as separation, because of their complete selectivity for the adsorption of specific guest molecules. Here, we report the control of the adsorption behaviour in a series of flexible MOFs, (H2dab)[M2(ox)3] (H2dab = 1,4-diammoniumbutane, M = Fe, Co, Ni, Zn, or Mg), having different central metals with analogous crystal structures. We found that a significant change in the selective adsorption behaviour for EtOH over MeCHO and MeCN is caused by the type of central metals, without changes in the crystal structures of all phases (except the Ni compound). A systematic study of adsorption measurements and structural analyses of the analogous MOFs reveals for the first time that the framework flexibility around the central metals of MOFs is truly related to the selective adsorption behaviour.

  59. Structural disorder, anisotropic micro-strain and cation vacancies in thermo-electric lead chalcogenides 査読有り

    Sebastian Christensen, Niels Bindzus, Mattia Sist, Masaki Takata, Bo Brummerstedt Iversen

    Physical Chemistry Chemical Physics 18 (23) 15874-15883 2016年

    DOI: 10.1039/c6cp01730d  

    ISSN:1463-9076

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    © 2016 the Owner Societies. Thermoelectric materials can interconvert heat and electricity, and the extraordinary thermoelectric properties of lead chalcogenides (PbX, X = S, Se, Te) attract immense scientific interest. A key topic is the role of the cation in reaching a very low thermal conductivity necessary for efficient energy conversion. Here we present new structural insights about the deceptively simple rock-salt lead chalcogenides through a comparative multi-temperature synchrotron powder X-ray diffraction study. For the first time, the presence of anisotropic microstrain broadening as well as lead vacancies are quantified for all three compounds. The microstrain implies extended breakage of cubic symmetry as a sign of the incipient ferroelectric nature of PbX. The degree of microstrain is correlated to the transition pressure of a symmetry reducing phase transition, and this trend can be explained by anion mediated s-p hybridization on lead. The observed number of vacancies is greatest for PbS (4-8%), but two samples of PbS show different cation occupancy, and thus sample-dependent vacancies might be the property that unifies conflicting results reported for PbX. Gram-Charlier analysis identifies a local non-spherical distribution of Pb; however, model unbiased maximum entropy analysis indicates that any static displacement of Pb, if present, is less than 0.2 Å at 100 K.

  60. Electronic phase transition in hollandite titanates BaxTi8 O16+δ 査読有り

    R. Murata, T. Sato, T. Okuda, Y. Horibe, H. Tsukasaki, S. Mori, N. Yamaguchi, K. Sugimoto, S. Kawaguchi, M. Takata, T. Katsufuji

    Physical Review B - Condensed Matter and Materials Physics 92 (22) 2015年12月14日

    DOI: 10.1103/PhysRevB.92.220408  

    ISSN:1098-0121

    eISSN:1550-235X

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    © 2015 American Physical Society. We studied the physical properties of hollandite titanates, BaxTi8O16+δ, which have double chains of edge-sharing TiO6 octahedra with d electrons in the t2g states. We found that there is an electronic phase transition at ∼220 K, at which various properties exhibit anomalies. This phase transition is characterized by a modulation in the TiO6 chains and a spectral weight transfer of over 2 eV in the optical conductivity spectrum, which are presumably caused by charge and orbital ordering of the Ti t2g electrons.

  61. Chemically Locked Bicelles with High Thermal and Kinetic Stability 査読有り

    Ryoichi Matsui, Masataka Ohtani, Kuniyo Yamada, Takaaki Hikima, Masaki Takata, Takashi Nakamura, Hiroyuki Koshino, Yasuhiro Ishida, Takuzo Aida

    Angewandte Chemie - International Edition 54 (45) 13284-13288 2015年11月1日

    DOI: 10.1002/anie.201506781  

    ISSN:1433-7851

    eISSN:1521-3773

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    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. In situ polymerization of a bicellar mixture composed of a phospholipid and polymerizable surfactants afforded unprecedented stable bicelles. The polymerized composite showed an aligned phase over a wide thermal range (25 to >90°C) with excellent 2H quadrupole splitting of the solvent signal, thus implying versatility as an alignment medium for NMR studies. Crosslinking of the surfactants also brought favorable effects on the kinetic stability and alignment morphology of the bicelles. This system could thus offer a new class of scaffolds for biomembrane models.

  62. Unusual Strong Incommensurate Modulation in a Tungsten-Bronze-Type Relaxor PbBiNb<inf>5</inf>O<inf>15</inf> 査読有り

    Kun Lin, Zhengyang Zhou, Laijun Liu, Hongqiang Ma, Jun Chen, Jinxia Deng, Junliang Sun, Li You, Hidetaka Kasai, Kenichi Kato, Masaki Takata, Xianran Xing

    Journal of the American Chemical Society 137 (42) 13468-13471 2015年10月28日

    DOI: 10.1021/jacs.5b08230  

    ISSN:0002-7863

    eISSN:1520-5126

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    © 2015 American Chemical Society. Pb- or Bi-based perovskite oxides have been widely studied and used because of their large ferroelectric polarization features induced by stereochemically active 6s2 lone pair electrons. It is intriguing whether this effect could exist in other related systems. Herein, we designed and synthesized a mixed Pb and Bi A site polar compound, PbBiNb5O15, with the TTB framework. The as-synthesized material turns out to be a relaxor with weak macroscopic ferroelectricity but adopts strong local polarizations. Whats more, unusual five orders of incommensurate satellite reflections with strong intensities were observed under the electron diffraction, suggesting that the modulation is highly developed with large amplitudes. The structural modulation was solved with a (3 + 1)D superspace group using high-resolution synchrotron radiation combined with anomalous dispersion X-ray diffraction technique to distinguish Pb from Bi. We show that the strong modulation mainly originates from lone-pair driven Pb2+-Bi3+ ordering in the large pentagonal caves, which can suppress the local polarization in x-y plane in long ranges. Moreover, the as-synthesized ceramics display strong relaxor ferroelectric feature with transition temperature near room temperature and moderate dielectric properties, which could be functionalized to be electromechanical device materials.

  63. Thermoresponsive actuation enabled by permittivity switching in an electrostatically anisotropic hydrogel 査読有り

    Youn Soo Kim, Mingjie Liu, Yasuhiro Ishida, Yasuo Ebina, Minoru Osada, Takayoshi Sasaki, Takaaki Hikima, Masaki Takata, Takuzo Aida

    Nature Materials 14 (10) 1002-1007 2015年10月24日

    DOI: 10.1038/nmat4363  

    ISSN:1476-1122

    eISSN:1476-4660

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    Electrostatic repulsion, long used for attenuating surface friction, is not typically employed for the design of bulk structural materials. We recently developed a hydrogel with a layered structure consisting of cofacially oriented electrolyte nanosheets. Because this unusual geometry imparts a large anisotropic electrostatic repulsion to the hydrogel interior, the hydrogel resisted compression orthogonal to the sheets but readily deformed along parallel shear. Building on this concept, here we show a hydrogel actuator that operates by modulating its anisotropic electrostatics in response to changes of electrostatic permittivity associated with a lower critical solution temperature transition. In the absence of substantial water uptake and release, the distance between the nanosheets rapidly expands and contracts on heating and cooling, respectively, so that the hydrogel lengthens and shortens significantly, even in air. An L-shaped hydrogel with an oblique nanosheet configuration can thus act as a unidirectionally proceeding actuator that operates without the need for external physical biases.

  64. Side Chain-Directed Assembly of Large Discotic π-Conjugated Molecules: Toward Tuning and Stabilization of Mesophases 査読有り

    Yusuke Tsutsui, Tsuneaki Sakurai, Kenichi Kato, Masaki Takata, Shu Seki

    Journal of Photopolymer Science and Technology 28 (4) 583-587 2015年10月5日

    DOI: 10.2494/photopolymer.28.583  

    ISSN:0914-9244

    eISSN:1349-6336

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    © 2015 SPST. A representatiπe π-conjugated motif, perylenediimide (PDI), when functionalized with taper-shaped semi-fluoroalkyl chains at one of its imide positions, self-assembled into various ordered phase structures depending on the type of side chains at the other imide position. Asymmetrical substitution by semi-fluoroalkyl/alkyl chains allowed the PDI molecule to form a rectangular columnar liquid crystalline mesophase while semi-fluoroalkyl/ triethyleneglycol-substitution resulted in a lamellar-packed crystalline mesophase. In both mesophases, the immiscible nature of superhydrophobic/hydrophobic or superhydrophobic/hydrophilic segments works as the major droving force to lead semi-fluoroalkyl/alkyl or semi-fluoroalkyl/oxyethyleneglycol nano-domains, resulting in high stability of the mesophases with the wide temperature range over 100ºC. The compound decorated with tapered semi-fluoroalkyl chains at the both imide positions exhibited complicated crystalline ordered phases with high thermal stability.

  65. Observation of an Orientation Change in Highly Oriented Layer-by-Layer Films of a Ruthenium Complex upon Oxidation Reaction 査読有り

    Katsuhiko Kanaizuka, Sono Sasaki, Takuya Nakabayashi, Hiroyasu Masunaga, Hiroki Ogawa, Takaaki Hikima, Masaki Takata, Masa Aki Haga

    Langmuir 31 (38) 10327-10330 2015年9月29日

    DOI: 10.1021/acs.langmuir.5b02679  

    ISSN:0743-7463

    eISSN:1520-5827

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    © 2015 American Chemical Society. Layer-by-layer films composed of redox-active ruthenium dimer and Zr(IV) ions were fabricated on an indium tin oxide electrode. The fabricating behavior was monitored by cyclic voltammetry and UV-vis absorption spectral measurements. The orientation of the film was also monitored by grazing-incidence small-angle and wide-angle X-ray scattering (GISAXS) measurements, and it has been clarified that this film has a crystalline structure. The peaks obtained by GISAXS were changed upon oxidation reaction, which indicates that a change in the orientation of the ruthenium dimer occurred in the film.

  66. The Role of a Three Dimensionally Ordered Defect Sublattice on the Acidity of a Sulfonated Metal-Organic Framework 査読有り

    Jared M. Taylor, Tokutaro Komatsu, Shun Dekura, Kazuya Otsubo, Masaki Takata, Hiroshi Kitagawa

    Journal of the American Chemical Society 137 (35) 11498-11506 2015年9月9日

    DOI: 10.1021/jacs.5b07267  

    ISSN:0002-7863

    eISSN:1520-5126

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    © 2015 American Chemical Society. Understanding the role that crystal imperfections or defects play on the physical properties of a solid material is important for any application. In this report, the highly unique crystal structure of the metal-organic framework (MOF) zirconium 2-sulfoterephthalate is presented. This MOF contains a large number of partially occupied ligand and metal cluster sites which directly affect the physical properties of the material. The partially occupied ligand positions give rise to a continuum of pore sizes within this highly porous MOF, supported by N<inf>2</inf> gas sorption and micropore analysis. Furthermore, this MOF is lined with sulfonic acid groups, implying a high proton concentration in the pore, but defective zirconium clusters are found to be effective proton trapping sites, which was investigated by a combination of AC impedance analysis to measure the proton conductivity and DFT calculations to determine the solvation energies of the protons in the pore. Based on the calculations, methods to control the pK<inf>a</inf> of the clusters and improve the conductivity by saturating the zirconium clusters with strong acids were utilized, and a 5-fold increase in proton conductivity was achieved using these methods. High proton conductivity of 5.62 × 10<sup>-3</sup> S cm<sup>-1</sup> at 95% relative humidity and 65 °C could be achieved, with little change down to 40% relative humidity at room temperature.

  67. Revisit: High resolution charge density study of α-rhombohedral boron using third-generation SR data at SPring-8 査読有り

    Eiji Nishibori, Hiroshi Hyodo, Kaoru Kimura, Masaki Takata

    Solid State Sciences 47 27-31 2015年9月1日

    DOI: 10.1016/j.solidstatesciences.2015.02.007  

    ISSN:1293-2558

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    © 2015 Elsevier Masson SAS. Experimental charge density of α-rhombohedral boron (α-B<inf>12</inf>) by a Maximum entropy method (MEM) has been re-investigated using the high resolution powder diffraction data measured at third-generation synchrotron radiation (SR) source, SPring-8. The present MEM charge density has many discrepancies from the previous MEM charge densities reported by Fujimori et al. and Hosoi et al. The data-resolution dependence of the MEM charge density was investigated using the present data. We found that diffraction data with d > 0.4 Å resolution range were needed to reveal qualitative bonding nature of α-B<inf>12</inf> at 100 K. The peculiar bonding natures, such as a bend B-B bond and a propeller-shaped bond, which were found in the previous studies have disappeared by using d > 0.4 Å data. The bonding nature of MEM charge density using the full data with d > 0.327 Å d-spacing range is well agreed with those of theoretical calculations. The present study suggests that resolution test is important for an accurate charge density study of boron related materials.

  68. Use of extension-deformation-based crystallisation of silk fibres to differentiate their functions in nature 査読有り

    Keiji Numata, Hiroyasu Masunaga, Takaaki Hikima, Sono Sasaki, Kazuhide Sekiyama, Masaki Takata

    Soft Matter 11 (31) 6335-6342 2015年8月21日

    DOI: 10.1039/c5sm00757g  

    ISSN:1744-683X

    eISSN:1744-6848

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    © The Royal Society of Chemistry 2015. β-Sheet crystals play an important role in determining the stiffness, strength, and optical properties of silk and in the exhibition of silk-type-specific functions. It is important to elucidate the structural changes that occur during the stretching of silk fibres to understand the functions of different types of fibres. Herein, we elucidate the initial crystallisation behaviour of silk molecules during the stretching of three types of silk fibres using synchrotron radiation X-ray analysis. When spider dragline silk was stretched, it underwent crystallisation and the alignment of the β-sheet crystals became disordered initially but was later recovered. On the other hand, silkworm cocoon silk did not exhibit further crystallisation, whereas capture spiral silk was predominantly amorphous. Structural analyses showed that the crystallisation of silks following extension deformation has a critical effect on their mechanical and optical properties. These findings should aid the production of artificial silk fibres and facilitate the development of silk-inspired functional materials.

  69. Ferroelectric-like metallic state in electron doped BaTiO<inf>3</inf> 査読有り

    J. Fujioka, A. Doi, D. Okuyama, D. Morikawa, T. Arima, K. N. Okada, Y. Kaneko, T. Fukuda, H. Uchiyama, D. Ishikawa, A. Q.R. Baron, K. Kato, M. Takata, Y. Tokura

    Scientific Reports 5 2015年8月20日

    DOI: 10.1038/srep13207  

    eISSN:2045-2322

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    We report that a ferroelectric-like metallic state with reduced anisotropy of polarization is created by the doping of conduction electrons into BaTiO 3, on the bases of x-ray/electron diffraction and infrared spectroscopic experiments. The crystal structure is heterogeneous in nanometer-scale, as enabled by the reduced polarization anisotropy. The enhanced infrared intensity of soft phonon along with the resistivity reduction suggests the presence of unusual electron-phonon coupling, which may be responsible for the emergent ferroelectric structure compatible with metallic state.

  70. Hybrid materials of Ni NP@MOF prepared by a simple synthetic method 査読有り

    Megumi Mukoyoshi, Hirokazu Kobayashi, Kohei Kusada, Mikihiro Hayashi, Teppei Yamada, Mitsuhiko Maesato, Jared M. Taylor, Yoshiki Kubota, Kenichi Kato, Masaki Takata, Tomokazu Yamamoto, Syo Matsumura, Hiroshi Kitagawa

    Chemical Communications 51 (62) 12463-12466 2015年8月11日

    DOI: 10.1039/c5cc04663g  

    ISSN:1359-7345

    eISSN:1364-548X

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    © The Royal Society of Chemistry 2015. We demonstrate a novel, simple synthetic method for metal (Ni) NPs in a MOF using the partial thermal decomposition of nickel(II) 2,5-dihydroxyterephthalate (Ni-MOF-74). The Ni NPs inside the Ni-MOF-74 are several nanometers in size, and the size can be precisely controlled by the heating conditions.

  71. Preparation of solid-solution type Fe-Co nanoalloys by synchronous deposition of Fe and Co using dual arc plasma guns 査読有り

    Masaaki Sadakiyo, Minako Heima, Tomokazu Yamamoto, Syo Matsumura, Masashi Matsuura, Satoshi Sugimoto, Kenichi Kato, Masaki Takata, Miho Yamauchi

    Dalton Transactions 44 (36) 15764-15768 2015年8月10日

    DOI: 10.1039/c5dt02815a  

    ISSN:1477-9226

    eISSN:1477-9234

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    © The Royal Society of Chemistry. We succeeded in the efficient preparation of well-dispersed Fe-Co nanoalloys (NAs) using the arc plasma deposition method. Synchronous shots of dual arc plasma guns were applied to a carbon support to prepare the solid-solution type Fe-Co NAs having an approximately 1 : 1 atomic ratio. The alloy structures with and without a reductive thermal treatment under a hydrogen atmosphere were examined using X-ray powder diffraction, scanning transmission electron microscopy (STEM) combined with energy-dispersive X-ray analysis, high resolution STEM, and magnetic measurements, suggesting that highly crystalline spherical particles of ordered B2-type Fe-Co NAs form by the thermal treatment of the deposited grains.

  72. Structural Basis for Polymer Packing and Solvation Properties of the Organogermanium Crystalline Polymer Propagermanium and Its Derivatives 査読有り

    Nobuhiro Mizuno, Eiji Nishibori, Mitsuru Oka, Takahito Jomori, Masaki Takata, Takashi Kumasaka

    Journal of Pharmaceutical Sciences 104 (8) 2482-2488 2015年8月1日

    DOI: 10.1002/jps.24486  

    ISSN:0022-3549

    eISSN:1520-6017

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    © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:2482-2488. Of organogermanium compounds known to have an immunostimulatory action, propagermanium [PGe; 3-oxygermylpropionic acid polymer, (C3H5GeO3.5)n] is the only one used as a pharmaceutical agent, to treat the hepatitis B virus in Japan. However, because of lack of information about its structure, PGe has been confused with a polymeric solid, repagermanium (RGe, Ge-132, poly-trans-[(2-carboxyethyl) germasesquioxane], (C18H30Ge6O21)n), which has the same essential formula as PGe. To clarify this issue, the structure of PGe was analyzed using X-ray diffraction (XRD). PGe has a polymeric ladder-shaped structure of a concatenated eight-membered ring composed of Ge £ O bonds, which is clearly distinguished from the infinite sheet structure in RGe. Moreover, we observed temperature or moisture-dependent transformations among these compounds using powder XRD. For instance, PGe was easily dissolved in water, and transformed to RGe by exposure to water vapor, but transformed into another straight-chain structure when exposed to aqueous solution. As a result of these findings, PGe was indicated to have labile polymer packing against RGe. These characteristics of PGe may affect pharmaceutical properties such as respective stability and solubility, which indicate its unique impact on physiological activity.

  73. Coordination nano-space as stage of hydrogen ortho–para conversion 査読有り

    Takashi Kosone, Akihiro Hori, Eiji Nishibori, Yoshiki Kubota, Akio Mishima, Masaaki Ohba, Hiroshi Tanaka, Kenichi Kato, Jungeun Kim, José Antonio Real, Susumu Kitagawa, Masaki Takata

    Royal Society Open Science 2 (7) 150006-150006 2015年7月

    出版者・発行元:The Royal Society

    DOI: 10.1098/rsos.150006  

    eISSN:2054-5703

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    The ability to design and control properties of nano-sized space in porous coordination polymers (PCPs) would provide us with an ideal stage for fascinating physical and chemical phenomena. We found an interconversion of nuclear-spin isomers for hydrogen molecule H <sub>2</sub> adsorbed in a Hofmann-type PCP, {Fe(pz)[Pd(CN) <sub>4</sub> ]} (pz=pyrazine), by the temperature dependence of Raman spectra. The ortho (o)–para (p) conversion process of H <sub>2</sub> is forbidden for an isolated molecule. The charge density study using synchrotron radiation X-ray diffraction reveals the electric field generated in coordination nano-space. The present results corroborate similar findings observed on different systems and confirm that o–p conversion can occur on non-magnetic solids and that electric field can induce the catalytic hydrogen o–p conversion.

  74. Distinct Substrate Effect on the Reversibility of the Metal-Insulator Transitions in Electrolyte-Gated VO2Thin Films 査読有り

    Masaki Nakano, Daisuke Okuyama, Keisuke Shibuya, Masaichiro Mizumaki, Hiroyuki Ohsumi, Masaro Yoshida, Masaki Takata, Masashi Kawasaki, Yoshinori Tokura, Takahisa Arima, Yoshihiro Iwasa

    Advanced Electronic Materials 1 (7) 1500093-1500093 2015年7月

    出版者・発行元:Wiley

    DOI: 10.1002/aelm.201500093  

    ISSN:2199-160X

    eISSN:2199-160X

  75. Metal-Organic Nanotube with Helical and Propeller-Chiral Motifs Composed of a C<inf>10</inf>-Symmetric Double-Decker Nanoring 査読有り

    Hiroshi Yamagishi, Takahiro Fukino, Daisuke Hashizume, Tadashi Mori, Yoshihisa Inoue, Takaaki Hikima, Masaki Takata, Takuzo Aida

    Journal of the American Chemical Society 137 (24) 7628-7631 2015年6月24日

    DOI: 10.1021/jacs.5b04386  

    ISSN:0002-7863

    eISSN:1520-5126

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    © 2015 American Chemical Society. Coassembly of an achiral ferrocene-cored tetratopic pyridyl ligand (FcL) with AgBF4 in CH2Cl2/MeCN (7:3 v/v) containing chiral Bu4N+ (+)- or (-)-menthylsulfate (MS∗-) results in the formation of an "optically active" metal-organic nanotube (FcNT) composed of a C10-symmetric double-decker nanoring featuring 10 FcL units and 20 Ag+ ions. The circular dichroism spectrum of FcNT along with its 2D X-ray diffraction (2D XRD) pattern indicates that the constituent metal-organic nanorings in FcNT stack one-handed helically on top of each other. A crystal structure of the dimeric double-decker model complex (Ag2(FcL′)2) from a ditopic ferrocene ligand (FcL′) and AgBF4 allowed for confirming the binding of MS∗- onto the Ag+ center of the complex. The results of detailed spectroscopic studies indicate that in its double-decker aromatic arrays, FcNT possibly possesses propeller-chiral twists in addition to the helically chiral structure, where the former is considerably more dynamic than the latter. Notably, both chiral structural motifs responded nonlinearly to an enantiomeric excess of MS∗- (majority rule) though with no stereochemical influence on one another.

  76. Rational synthesis of organic thin films with exceptional long-range structural integrity 査読有り

    Noriya Seiki, Yoshiaki Shoji, Takashi Kajitani, Fumitaka Ishiwari, Atsuko Kosaka, Takaaki Hikima, Masaki Takata, Takao Someya, Takanori Fukushima

    Science 348 (6239) 1122-1126 2015年6月5日

    DOI: 10.1126/science.aab1391  

    ISSN:0036-8075

    eISSN:1095-9203

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    Highly oriented, domain-boundary-free organic thin films could find use in various high-performance organic materials and devices. However, even with state-of-the-art supramolecular chemistry, it is difficult to construct organic thin films with structural integrity in a size regime beyond the micrometer length scale. We show that a space-filling design, relying on the two-dimensional (2D) nested hexagonal packing of a particular type of triptycene, enables the formation of large-area molecular films with long-range 2D structural integrity up to the centimeter length scale by vacuum evaporation, spin-coating, and cooling from the isotropic liquid of the triptycene. X-ray diffraction analysis and microscopic observations reveal that triptycene molecules form a completely oriented 2D (hexagonal triptycene array) + 1D (layer stacking) structure, which is key for the long-range propagation of structural order.

  77. Photoalignment of an azobenzene-based chromonic liquid crystal dispersed in triacetyl cellulose: Single-layer alignment films with an exceptionally high order parameter 査読有り

    Masaki Matsumori, Ayami Takahashi, Yasushi Tomioka, Takaaki Hikima, Masaki Takata, Takashi Kajitani, Takanori Fukushima

    ACS Applied Materials and Interfaces 7 (21) 11074-11078 2015年6月3日

    DOI: 10.1021/acsami.5b02577  

    ISSN:1944-8244

    eISSN:1944-8252

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    © 2015 American Chemical Society. Single-layer thin alignment films of dye molecules are of growing importance, particularly for state-of-the-art LCD technology. Here we show that a sequential process involving the photoalignment and humidification of a chromonic liquid crystalline azobenzene (brilliant yellow; BY) dispersed in a triacetyl cellulose (TAC) matrix gives a thin alignment film with an exceptionally high order parameter (0.81). Spectroscopic and X-ray diffraction analyses of a BY/TAC composite film in each alignment process revealed that brief humidification triggers restructuring of the BY assembly from 1D nematic-like order to anisotropic 2D columnar order, resulting in the dramatic increase in the order parameter.

  78. Morphotropic phase boundary in the Pb-Free (1 - X)BiTi<inf>3/8</inf>Fe<inf>2/8</inf>Mg<inf>3/8</inf>O<inf>3</inf>-xCaTiO<inf>3</inf> System: Tetragonal polarization and enhanced electromechanical properties 査読有り

    Pranab Mandal, Alicia Manjõn-Sanz, Alex J. Corkett, Tim P. Comyn, Karl Dawson, Timothy Stevenson, James Bennett, Leonard F. Henrichs, Andrew J. Bell, Eiji Nishibori, Masaki Takata, Marco Zanella, Michelle R. Dolgos, Umut Adem, Xinming Wan, Michael J. Pitcher, Simon Romani, T. Thao Tran, P. Shiv Halasyamani, John B. Claridge, Matthew J. Rosseinsky

    Advanced Materials 27 (18) 2883-2889 2015年5月13日

    DOI: 10.1002/adma.201405452  

    ISSN:0935-9648

    eISSN:1521-4095

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    © 2015 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Lead-free bismuth-based perovskite oxides with polarization directed along the [001]p primitive perovskite unit cell edge, analogous to tetragonal PbTiO3, are synthesized at ambient pressure. Enhanced piezoelectric properties, large polarizations, and high depolarization temperatures are observed in the wide morphotropic phase boundary region formed with a rhombohedral phase, with up to 92.5% Bi on the perovskite A site.

  79. All-In–All-Out Magnetic Domains: X-Ray Diffraction Imaging and Magnetic Field Control 査読有り

    Samuel Tardif, Soshi Takeshita, Hiroyuki Ohsumi, Jun-ichi Yamaura, Daisuke Okuyama, Zenji Hiroi, Masaki Takata, Taka-hisa Arima

    Physical Review Letters 114 (14) 147205-147205 2015年4月8日

    出版者・発行元:American Physical Society (APS)

    DOI: 10.1103/physrevlett.114.147205  

    ISSN:0031-9007

    eISSN:1079-7114

  80. Evaluation of the intrinsic charge carrier transporting properties of linear- and bent-shaped π-extended benzo-fused thieno[3,2-b]thiophenes 査読有り

    Yusuke Tsutsui, Tsuneaki Sakurai, Sojiro Minami, Koji Hirano, Tetsuya Satoh, Wakana Matsuda, Kenichi Kato, Masaki Takata, Masahiro Miura, Shu Seki

    Physical Chemistry Chemical Physics 17 (15) 9624-9628 2015年4月

    DOI: 10.1039/c5cp00785b  

    ISSN:1463-9076

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    © the Owner Societies 2015. The intrinsic charge carrier transporting properties of two isomeric linear- and bent-shaped 7-ring benzo-fused thieno[3,2-b] thiophenes and their octyl-substituted analogues were newly investigated using flash-photolysis (FP-) and field-induced (FI-) time-resolved microwave conductivity (TRMC) techniques. FP-TRMC study in the solid state revealed that octyl-substitution potentially improved the photoconductivity due to the enhanced crystalline lamellar packing. After this screening process, local-scale hole mobilities at the thienoacene-poly(methylmethacrylate) insulator interfaces were precisely recorded using FI-TRMC, reaching up to 4.5 cm2 V-1 s-1 for the linear-shaped non-alkylated thienoacene. The combination of FP- and FI-TRMC measurements provides a rapid and quantitative evaluation scheme even for a variety of compounds with some issues in the processing conditions, leading to the optimized structure of the compounds used as active (interfacial) layers in practical electronic devices. This journal is

  81. X-ray induced lock-in transition of cycloidal magnetic order in a multiferroic perovskite manganite 査読有り

    Y. Yamasaki, H. Nakao, Y. Murakami, T. Nakajima, A. Lafuente Sampietro, H. Ohsumi, M. Takata, T. Arima, Y. Tokura

    Physical Review B - Condensed Matter and Materials Physics 91 (10) 100403(R)-100403(R) 2015年3月24日

    DOI: 10.1103/PhysRevB.91.100403  

    ISSN:1098-0121

    eISSN:1550-235X

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    © 2015 American Physical Society. We report the x-ray photoexcitation effects on cycloidal magnetic order in a multiferroic perovskite-type manganite Gd0.5Tb0.5MnO3. The material exhibits a competition between the P(electricpolarization)||a ferroelectric state with the commensurate (C) ab-plane cycloidal and the P||c ferroelectric state with the incommensurate (IC) bc-plane cycloidal spin structure. The phase transition between these two phases can be induced by an application of a magnetic field. We found that the x-ray irradiation can induce the bidirectional and persistent phase transition between IC and C phases. The nonresonant x-ray magnetic diffraction revealed that both the initial and the x-ray induced phases have the bc-plane cycloidal magnetic structure, whereas the magnetic wave number varies between IC and C. The x-ray induced bc-plane cycloidal C phase is thus the hidden multiferroic phase in the Gd1-xTbxMnO3 system, which does not show up with the application of any static field.

  82. One-step hydrothermal synthesis of V<inf>1-x</inf>W<inf>x</inf>O<inf>2</inf>(M/R) nanorods with superior doping efficiency and thermochromic properties 査読有り

    Ru Chen, Lei Miao, Haoliang Cheng, Eiji Nishibori, Chengyan Liu, Toru Asaka, Yuji Iwamoto, Masaki Takata, Sakae Tanemura

    Journal of Materials Chemistry A 3 (7) 3726-3738 2015年2月21日

    DOI: 10.1039/c4ta05559d  

    ISSN:2050-7488

    eISSN:2050-7496

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    © The Royal Society of Chemistry 2015. Pure phase V1-xWxO2(M/R) nanorods with superb metal-insulator transition properties were obtained in tungsten (W)-doped level ranges from 0.5 to 2.0 at% using a one-step hydrothermal treatment without additional annealing steps. The assured level of W doping greatly promotes the grain growth of pure phase vanadium oxide (VO2)(M/R) and simultaneously the phase transition temperature (Tc) is depressed as much as 103°C per at% W for the V1-xWxO2 nanorods when x = 1.0-2.0 at%. After mixing the pure phase VO2(M) (W-doped 0.5 at%, phase transition at 47°C) nanorods with acrylic resin, the integrated visible transmission of the VO2 composite coating on glass is up to 60.6% and the integrated solar modulation efficiency is up to 10.3%. These results mean that the superior thermochromic property will greatly favor the practical application of VO2-based smart windows.

  83. Luminescence of fusion materials of polymeric chain-structured lanthanide complexes 査読有り

    Saki Sato, Ayumi Ishii, Chisaki Yamada, Junguen Kim, Chul Ho Song, Akihiko Fujiwara, Masaki Takata, Miki Hasegawa

    Polymer Journal 47 (2) 195-200 2015年2月7日

    DOI: 10.1038/pj.2014.88  

    ISSN:0032-3896

    eISSN:1349-0540

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    © 2015 The Society of Polymer Science, Japan (SPSJ) All rights reserved. Polymeric chain-structured complexes were prepared with helical lanthanide complexes (LnL; Ln=Eu III, Tb III, Gd III) and benzene-dicarboxylate derivatives (benzene-1,4-dicarboxylate (bdc), 2-aminoterephtalate (atpa) and 2-hydoloxyterephtalate (htpa)), which show some noteworthy physicochemical properties, photoluminescence and thermal stabilities. The complex EuL-bdc shows bright luminescence originating from Eu III by UV excitation. The emission color can be tuned by mixing with TbL. The structures of these chain complexes were clarified with synchrotron X-ray powder diffraction measurements. The derivation of the linker moiety (bdc, atpa or htpa) was found to affect the intermetal energy transfer from Tb III to Eu III.

  84. Remarkable oxygen intake/release of BaYMn<inf>2</inf>O<inf>5+δ</inf> viewed from high-temperature crystal structure 査読有り

    Teruki Motohashi, Taira Takahashi, Makoto Kimura, Yuji Masubuchi, Shinichi Kikkawa, Yoshiki Kubota, Yoji Kobayashi, Hiroshi Kageyama, Masaki Takata, Susumu Kitagawa, Ryotaro Matsuda

    Journal of Physical Chemistry C 119 (5) 2356-2363 2015年2月5日

    DOI: 10.1021/jp511648b  

    ISSN:1932-7447

    eISSN:1932-7455

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    © 2015 American Chemical Society. Crystal structure of double-perovskite type BaYMn2O5+δ was studied by high-temperature synchrotron X-ray diffraction (SXRD) under precisely controlled oxygen pressure to gain deeper understanding of the remarkable oxygen intake/release capability of this oxide. The in situ SXRD analysis at 750 °C revealed that this oxide undergoes a distinct structural change upon lowering oxygen pressure, from a slightly oxygen-deficient "δ = 1" phase (BaYMn2O5.89; P(O2) = 103 Pa) to an oxygen-vacancy ordered "δ = 0.5" phase (BaYMn2O5.51; P(O2) = 10 Pa). The BaYMn2O5.89 structure (orthorhombic Cmmm) involves statistical distribution of oxygen vacancies within the yttrium plane. Meanwhile, the BaYMn2O5.51 structure (orthorhombic Icma) contains arrays of pyramidal MnO5 and octahedral MnO6 forming an alternate ordering, which is stabilized by a particular Mn3+ orbital ordering with collective displacements of Y3+ arrays. Thus, the discontinuous change in the oxygen content can be attributed to the structural reconstruction with oxygen/vacancy redistribution accompanied by yttrium displacement organization.

  85. Mapping the complete bonding network in KBH<inf>4</inf> using the combined power of powder diffraction and maximum entropy method 査読有り

    Niels Bindzus, Fausto Cargnoni, Carlo Gatti, Bo Richter, Torben R. Jensen, Masaki Takata, Bo B. Iversen

    Computational and Theoretical Chemistry 1053 245-253 2015年2月1日

    DOI: 10.1016/j.comptc.2014.09.014  

    ISSN:2210-271X

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    © 2014 Elsevier B.V. The combined power of the maximum entropy method (MEM) and synchrotron powder X-ray diffraction (SPXRD) is exerted to accurately reconstruct the electron density distribution (EDD) of the hydrogen storage material, KBH4. Its crystal structure features thermally activated disorder among the BH4- moieties, and weak secondary bonding effects occupy a key role in determining the energetic barrier for this dynamical effect. The MEM reconstruction is meticulously optimised and inspected for errors, in what may be envisaged as a general manual for this kind of studies. The successful outcome constitutes an experimental EDD of cutting-edge quality, from which atomic charges and the complete bonding network are mapped by topological descriptors. Remarkably, the chemical insights even extend to the delicate interplay of closed-shell bonding in excellent correspondence with ab initio and two-channel MEM calculations. For the current class of functional materials, access to such subtle electronic features is essential for the fundamental understanding of hydrogen desorption pathways.

  86. Translation of the assembling trajectory by preorganisation: A study of the magnetic properties of 1D polymeric unpaired electrons immobilised on a discrete nanoscopic scaffold 査読有り

    Vakayil K. Praveen, Yohei Yamamoto, Takanori Fukushima, Yoshihide Tsunobuchi, Koji Nakabayashi, Shin Ichi Ohkoshi, Kenichi Kato, Masaki Takata, Takuzo Aida

    Chemical Communications 51 (7) 1206-1209 2015年1月25日

    DOI: 10.1039/c4cc08942a  

    ISSN:1359-7345

    eISSN:1364-548X

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    © The Royal Society of Chemistry 2015. A nitronyl nitroxide (NN)-appended hexabenzocoronene (HBCNN), when allowed to coassemble with bis(hexafluoroacetylacetonato)cobalt(ii), forms a coaxial nanotubular architecture featuring NN-Co(ii) coordinated copolymer chains immobilised on the outer and inner nanotube surfaces. Upon lowering the temperature, this nanotube has enhanced magnetic susceptibility below 10 K. This journal is

  87. High tensile strength fiber of poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] processed by two-step drawing with intermediate annealing 査読有り

    Taizo Kabe, Chizuru Hongo, Toshihisa Tanaka, Takaaki Hikima, Masaki Takata, Tadahisa Iwata

    Journal of Applied Polymer Science 132 (2) 2015年1月10日

    出版者・発行元:Wiley

    DOI: 10.1002/app.41258  

    ISSN:0021-8995

    eISSN:1097-4628

  88. 19pCD-8 BaV_<10>O_<15>の三量体相転移と高温相の異常

    梶田 倫正, 波多野 慶, 池田 裕明, 蘆澤 美佐, 能上 絢香, 金 廷恩, 高田 昌樹, 勝藤 拓郎

    日本物理学会講演概要集 70 2204-2204 2015年

    出版者・発行元:一般社団法人日本物理学会

    DOI: 10.11316/jpsgaiyo.70.2.0_2204  

    ISSN:2189-079X

  89. 18pCH-10 極性半導体Ge_<1-x>Mn_xTe の磁気相図

    クリーナー M., 中島 多朗, 金子 良夫, 吉川 明子, 于 秀珍, 橋爪 大輔, 加藤 健一, 高田 昌樹, 遠藤 徳明, 有馬 孝尚, 十倉 好紀, 田口 康二郎

    日本物理学会講演概要集 70 951-951 2015年

    出版者・発行元:一般社団法人日本物理学会

    DOI: 10.11316/jpsgaiyo.70.2.0_951  

    ISSN:2189-079X

  90. 1B01 ディスク状分子からなる複雑な三次元構造(液晶化学・材料,口頭発表,2015年日本液晶学会討論会)

    梶谷 孝, 本川 究理, 橋爪 大輔, 高田 昌樹, 福島 孝典

    日本液晶学会討論会講演予稿集 2015 _1B01-1_-_1B01-2 2015年

    出版者・発行元:日本液晶学会

    DOI: 10.11538/ekitou.2015.0__1B01  

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    Triphenylene has been the most representative discotic mesogen. In particular, hexaalkoxytriphenylene has been used for designing many columnar liquid crystalline (LC) materials. Recently, we developed a new triphenylene-based mesogen having six carboxylic ester groups. We found that this mesogen, when modified with paraffinic side chains, can self-assemble to form a hexagonal columnar assembly with an exceptionally wide-range 2D lattice correlation. Furthermore, by virtue of the strong intercolumnar dipole-dipole interaction, the LC triphenylenes spontaneously align homeotropically on a wide variety of solid substrates. More recently, we found that the LC triphenylenes, when bearing certain ionic functionality at the terminal of each paraffinic side chain, assemble into an unprecedented complex three-dimensional architecture.

  91. Element-selective visualization for materials science using synchrotron X-ray two-wavelength anomalous powder diffraction data

    Nishibori Eiji, Takata Masaki

    Transactions of the Materials Research Society of Japan 40 (2) 165-168 2015年

    出版者・発行元:The Materials Research Society of Japan

    DOI: 10.14723/tmrsj.40.165  

    ISSN:1382-3469

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    Algorithms for determining the element-selective charge density are developed using two-wavelength anomalous synchrotron X-ray powder diffraction (MAPD) data. We have reported that an algorithm of element-selective charge density study from three wavelengths MAPD using near K absorption edge. The present study, we developed an algorithm from two wavelengths MAPD using near L<sub>III</sub> absorption edge. The method is employed in order to investigate a large anharmonic thermal vibration of Gold atom in Gold metal complex, Au(tmdt)<sub>2</sub> (tmdt: trimethylene- tetrathiafulvalene-dithiolate).

  92. An anisotropic hydrogel with electrostatic repulsion between cofacially aligned nanosheets 査読有り

    Mingjie Liu, Yasuhiro Ishida, Yasuo Ebina, Takayoshi Sasaki, Takaaki Hikima, Masaki Takata, Takuzo Aida

    Nature 517 (7532) 68-72 2015年1月1日

    DOI: 10.1038/nature14060  

    ISSN:0028-0836

    eISSN:1476-4687

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    © 2015 Macmillan Publishers Limited. Machine technology frequently putsmagnetic or electrostatic repulsive forces to practical use, as inmaglev trains, vehicle suspensions or non-contact bearings1,2. Incontrast, materials designoverwhelmingly focuses on attractive interactions, such as in the many advanced polymer-based composites, where inorganic fillers interact with a polymer matrix toimprovemechanical properties. However, articular cartilage strikingly illustrates how electrostatic repulsion can be harnessed to achieve unparalleled functional efficiency: it permits virtually frictionless mechanical motion within joints, even under high compression3,4. Here we describe a composite hydrogel with anisotropic mechanical properties dominated by electrostatic repulsion between negatively charged unilamellar titanatenanosheets5 embedded within it.Crucial to the behaviour of this hydrogel is the serendipitous discovery of cofacial nanosheet alignment in aqueous colloidal dispersions subjected to a strong magnetic field, which maximizes electrostatic repulsion6 andthereby induces a quasi-crystalline structural ordering7,8 overmacroscopic length scales and with uniformly large face-to-face nanosheet separation.We fix this transiently induced structural order by transforming the dispersion into a hydrogel9,10 using light-triggered in situ vinyl polymerization11. The resultant hydrogel, containing charged inorganic structures that align cofacially in amagnetic flux12-19, deforms easily under shear forces applied parallel to the embedded nanosheets yet resists compressive forces applied orthogonally. We anticipate that the concept of embedding anisotropic repulsive electrostatics within a composite material, inspired by articular cartilage, will open up new possibilities for developing soft materials with unusual functions.

  93. Visualizing patterned thin films by grazing-incidence small-angle X-ray scattering coupled with computed tomography 査読有り

    Hiroki Ogawa, Yukihiro Nishikawa, Akihiko Fujiwara, Mikihito Takenaka, Yi Chin Wang, Toshiji Kanaya, Masaki Takata

    Journal of Applied Crystallography 48 1645-1650 2015年

    DOI: 10.1107/S1600576715016684  

    ISSN:0021-8898

    eISSN:1600-5767

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    © 2015 International Union of Crystallography. Images of the spatial distribution of nanostructures in thin films were successfully reconstructed by grazing-incidence small-angle X-ray scattering (GISAXS) coupled with computed tomography (CT) measurements. As a model sample of inhomogeneous thin films, a thin film was patterned with four characters (F, B, S and L) consisting of nanoparticles of gold (Au), platinum (Pt), Au/Pt and Pt/Au, respectively, on a silicon substrate. The characters each produced respective two-dimensional GISAXS images which reflect the nanoparticle structures and their correlations in the thin film. The application of the GISAXS-CT technique to the characteristic scattering GISAXS intensity of each component enables one to reconstruct the images of each character independently. Moreover, it was found that the patterned images could be reconstructed even from very weak scattered intensities at higher q positions and the diffuse intensities. These results indicate that the GISAXS-CT method is a powerful tool to obtain distinct reconstruction images detailing the particle size, shape and surface roughness.

  94. Systematic studies on side-chain structures of phthalocyaninato-polysiloxanes: Polymerization and self-assembling behaviors 査読有り

    Satoru Yoneda, Tsuneaki Sakurai, Toru Nakayama, Kenichi Kato, Masaki Takata, Shu Seki

    Journal of Porphyrins and Phthalocyanines 19 (1-3) 160-170 2015年1月1日

    DOI: 10.1142/S1088424614501053  

    ISSN:1088-4246

    eISSN:1099-1409

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    © 2015 World Scientific Publishing Company. A series of dihydroxysilicon phthalocyanines having soluble side chains were synthesized and their bulk-state polymerization capability was investigated. Detailed spectroscopic study of the obtained phthalocyaninato-polysiloxanes revealed that strong electron donating ability and small steric hindrance of the peripheral substituents are the dominant factors to afford high-molecular weight polymers. The polymers show the behaviors of columnar liquid crystal (LC), which is clarified by the presence of clear X-ray diffraction patterns with a hexagonal lattice and birefringent textures in polarized optical microscopy. Because of the siloxane covalent bonds through central silicon atoms, phthalocyaninato-polysiloxanes accommodate one-dimensional phthalocyanine arrays with strong π-electronic couplings, thus exhibiting colmnar LC property even for the derivatives carrying short peripheral chains and leading to the relatively higher density of π-electron systems in the materials. This tendency is different from typical discotic small molecules that require optimum side chain structures for LC formation.

  95. Crystallization behaviors of poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate]/poly(ethylene glycol) graft TEMPO-oxidized cellulose nanofiber blends

    Jiaqi Zhang, Shuji Fujizawa, Akira Isogai, Takaaki Hikima, Masaki Takata, Tadahisa Iwata

    Polymer Degradation and Stability 110 529-536 2014年12月

    DOI: 10.1016/j.polymdegradstab.2014.09.022  

    ISSN:0141-3910

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    © 2014 Elsevier Ltd. To accelerate the crystallization rate of poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate] [P(3HB-co-4HB)] that is a microbial and biodegradable polyester, poly(ethylene glycol) graft TEMPO-oxidized cellulose nanofiber (PEG-TOCN) was blended as a nucleating agent. The PEG was only blended and confirmed the effect on the difference between PEG-TOCN and PEG in all samples. The non-isothermal crystallization and isothermal crystallization behaviors of P(3HB-co-4HB) with three kinds of different 4HB contents blended with PEG-TOCN or PEG were investigated by differential scanning calorimeter, wide-angle X-ray diffraction, polarizing microscope and tensile test. The crystallization half time (t1/2) was drastically decreased by blended with PEG-TOCN, indicating that the crystallization rate was accelerated in all cases. The POM images showed that the PEG-TOCN worked effectively to increase both the growth rate and amounts of spherulites of P(3HB-co-4HB). In addition, the crystallinity of PEG-TOCN blending samples was higher than that of non-blended samples in all cases.

  96. Continuous control of optical gaps in quasi-one-dimensional bromide-bridged platinum complexes by utilizing chemical pressure

    Shohei Kumagai, Hiroaki Iguchi, Shinya Takaishi, Brian K. Breedlove, Masahiro Yamashita, Hiroyuki Matsuzaki, Hiroshi Okamoto, Kenichi Kato, Masaki Takata

    Inorganic Chemistry 53 (21) 11764-11769 2014年11月3日

    DOI: 10.1021/ic502071u  

    ISSN:0020-1669

    eISSN:1520-510X

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    © 2014 American Chemical Society. The optical gap in a series of bromo-bridged platinum chain complexes, [Pt(en)2Br](Cn-Y)2·H2O (en = ethylenediamine; Cn-Y = dialkyl sulfosuccinate; n = the number of carbon atoms), was controlled by using chemical pressure. From the single-crystal structure, [Pt(en)2Br](C6-Y)2·H2O is in a mixed-valence state at 200 K. In addition, Pt-Pt distances decreased with an increase in n or with a decrease in the temperature. Continuous decreases in the optical gaps upon cooling were observed for n = 5, 7. The smallest gap of 1.20 eV was observed for n = 7 at 50 K. For n = 12, the complex was still in a mixed-valence state at 5 K, although the Pt-Pt distance was quite short. This is probably because of the energetic mismatch between 5dz2 orbitals of the Pt ions and 4pz orbitals of the Br ions.

  97. An ordered bcc CuPd nanoalloy synthesised via the thermal decomposition of Pd nanoparticles covered with a metal-organic framework under hydrogen gas

    Guangqin Li, Hirokazu Kobayashi, Kohei Kusada, Jared M. Taylor, Yoshiki Kubota, Kenichi Kato, Masaki Takata, Tomokazu Yamamoto, Syo Matsumura, Hiroshi Kitagawa

    Chemical Communications 50 (89) 13750-13753 2014年10月14日

    DOI: 10.1039/c4cc05941g  

    ISSN:1359-7345

    eISSN:1364-548X

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    Presented here is the synthesis of an ordered bcc copper-palladium nanoalloy, via the decomposition of a Pd nanoparticle@metal-organic framework composite material. In situ XRD measurements were performed in order to understand the mechanism of the decomposition process. This result gives a further perspective into the synthesis of new nanomaterials via metal-organic framework decomposition. © 2014 Partner Organisations.

  98. 2,6-Diphenyl- and -distyryl-capped 3,7-dialkoxybenzo[1,2-b:4,5-b′]dithiophenes and their dithieno-annulated higher homologs: Structural phase transition with enhanced charge carrier mobility

    Sojiro Minami, Marina Ide, Koji Hirano, Tetsuya Satoh, Tsuneaki Sakurai, Kenichi Kato, Masaki Takata, Shu Seki, Masahiro Miura

    Physical Chemistry Chemical Physics 16 (35) 18805-18812 2014年8月13日

    DOI: 10.1039/c4cp03002h  

    ISSN:1463-9076

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    Synthesis of the title benzo[1,2-b:4,5-b′]dithiophenes was achieved using 2-ethylhexyl 3,7-dihydroxybenzo[1,2-b:4,5-b′]dithiophene-2,6-dicarboxylate as the common starting material. The effect of the introduction of phenyl and styryl groups as well as thieno-annulation to the benzo[1,2-b:4,5-b′]dithiophene core on π-conjugation was estimated by means of absorption and emission spectrometry and cyclic voltammetry. The phase behaviours of the compounds were also observed by differential scanning calorimetry and the dithieno-annulated higher homologs were found to show a solid-solid (crystalline-crystalline) phase transition. Then, intrinsic charge carrier mobilities in the π-systems were measured by the flash-photolysis time-resolved microwave conductivity (FP-TRMC) method and the values were in the range of 0.04-0.17 cm2 V-1 s-1. Remarkably, the thieno-annulated and phenyl-capped derivative showed a temperature/phase-dependent hole mobility profile with 3-fold increment in the second crystalline phase above 100 °C. © the Partner Organisations 2014.

  99. Hydrogen storage in Pd nanocrystals covered with a metal-organic framework

    Guangqin Li, Hirokazu Kobayashi, Jared M. Taylor, Ryuichi Ikeda, Yoshiki Kubota, Kenichi Kato, Masaki Takata, Tomokazu Yamamoto, Shoichi Toh, Syo Matsumura, Hiroshi Kitagawa

    Nature Materials 13 (8) 802-806 2014年8月

    DOI: 10.1038/nmat4030  

    ISSN:1476-1122

    eISSN:1476-4660

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    Hydrogen is an essential component in many industrial processes. As a result of the recent increase in the development of shale gas, steam reforming of shale gas has received considerable attention as a major source of H 2, and the more efficient use of hydrogen is strongly demanded. Palladium is well known as a hydrogen-storage metal and an effective catalyst for reactions related to hydrogen in a variety of industrial processes. Here, we present remarkably enhanced capacity and speed of hydrogen storage in Pd nanocrystals covered with the metal-organic framework (MOF) HKUST-1 (copper(II) 1,3,5- benzenetricarboxylate). The Pd nanocrystals covered with the MOF have twice the storage capacity of the bare Pd nanocrystals. The significantly enhanced hydrogen storage capacity was confirmed by hydrogen pressure-composition isotherms and solid-state deuterium nuclear magnetic resonance measurements. The speed of hydrogen absorption in the Pd nanocrystals is also enhanced by the MOF coating. © 2014 Macmillan Publishers Limited. All rights reserved.

  100. Shape-dependent hydrogen-storage properties in Pd nanocrystals: Which does hydrogen prefer, octahedron (111) or cube (100)?

    Guangqin Li, Hirokazu Kobayashi, Shun Dekura, Ryuichi Ikeda, Yoshiki Kubota, Kenichi Kato, Masaki Takata, Tomokazu Yamamoto, Syo Matsumura, Hiroshi Kitagawa

    Journal of the American Chemical Society 136 (29) 10222-10225 2014年7月23日

    DOI: 10.1021/ja504699u  

    ISSN:0002-7863

    eISSN:1520-5126

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    Pd octahedrons and cubes enclosed by {111} and {100} facets, respectively, have been synthesized for investigation of the shape effect on hydrogen-absorption properties. Hydrogen-storage properties were investigated using in situ powder X-ray diffraction, in situ solid-state 2H NMR and hydrogen pressure-composition isotherm measurements. With these measurements, it was found that the exposed facets do not affect hydrogen-storage capacity; however, they significantly affect the absorption speed, with octahedral nanocrystals showing the faster response. The heat of adsorption of hydrogen and the hydrogen diffusion pathway were suggested to be dominant factors for hydrogen-absorption speed. Furthermore, in situ solid-state 2H NMR detected for the first time the state of 2H in a solid-solution (Pd + H) phase of Pd nanocrystals at rt. © 2014 American Chemical Society.

  101. Synchrotron X-ray powder diffraction and convergent beam electron diffraction studies on the cubic phase of MgV<inf>2</inf>O<inf>4</inf> spinel

    Seiji Niitaka, Soyeon Lee, Yoshifumi Oshima, Kenichi Kato, Daisuke Hashizume, Masaki Takata, Hidenori Takagi

    Journal of Solid State Chemistry 215 184-188 2014年7月

    DOI: 10.1016/j.jssc.2014.03.037  

    ISSN:0022-4596

    eISSN:1095-726X

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    The A V2O4 (A=Mg2+, Zn2+, Cd2+) spinels are three-dimensional spin-1 frustrated systems with orbital degree of freedom, which have been known to possess intriguing orbital states causing releases of spin frustration at low temperatures. We have performed synchrotron X-ray and convergent beam electron diffraction measurements for one of these vanadates, MgV2O4 in order to clarify its crystal structure in the high temperature cubic phase, which is regarded as an important starting point for understanding the details of the low temperature phase. We have successfully observed that the [001] zone axis convergent beam electron diffraction pattern exhibits 4mm symmetry, suggesting the space group of Fd3̄m in the cubic MgV2O4. It has also been demonstrated that the crystal structure of the cubic MgV 2O4 contains VO6 octahedra elongated along the threefold rotation axis. Based on our results, we discuss the orbital states of MgV2O4 as well as the other spinel vanadates. © 2014 Elsevier Inc.

  102. About the international year of crystallography 2014: Pioneers of polymer structural chemistry in Japan

    Masaki Takata

    Kobunshi 63 (7) 446 2014年7月

    ISSN:0454-1138

  103. Magnetically induced anisotropic orientation of graphene oxide locked by in situ hydrogelation

    Linlin Wu, Masataka Ohtani, Masaki Takata, Akinori Saeki, Shu Seki, Yasuhiro Ishida, Takuzo Aida

    ACS Nano 8 (5) 4640-4649 2014年5月27日

    DOI: 10.1021/nn5003908  

    ISSN:1936-0851

    eISSN:1936-086X

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    A general method to prepare polymer gels containing anisotropically oriented graphene oxide (GO) or reduced graphene oxide (RGO) was developed, by using the magnetically induced orientation of GO. Under a magnetic field, an aqueous dispersion of GO was gelated by in situ cross-linking polymerization of an acryl monomer and a cross-linker. In the resultant hydrogel, the orientation of GO was retained even in the absence of the magnetic field, because the gel network trapped GO via noncovalent interactions and efficiently suppressed the structural relaxation of GO. The locked structure enabled quantitative investigation on the magnetic orientation of GO using 2D small-Angle X-ray scattering, which revealed that GO nanosheets orient parallel to the magnetic field with an order parameter of up to 0.80. Systematic studies with varying gelation conditions indicate that the present method can afford a wide range of GO-hybridized anisotropic materials, in terms of GO alignment direction, sample shape, and GO concentration. Also by virtue of the locked structure, the orientation of GO in the hydrogel was well preserved throughout the in situ chemical reduction of GO, yielding an RGO-hybridized anisotropic hydrogel, as well as the conversion of the hydrogel into organo- and ionogels through the replacement of the internal water with solvents. As a preliminary demonstration of the present method for practical application, a polymer-composite film containing RGO oriented vertical to the film surface was prepared, and its anisotropically enhanced electroconductivity along the orientation direction of RGO was confirmed by the flash-photolysis time-resolved microwave conductivity measurement. © 2014 American Chemical Society.

  104. Advanced Soft Material Beamline Consortium at SPring-8 (FSBL)

    Atsushi Takahara, Toshiro Takeda, Toshiji Kanaya, Nobuaki Kido, Kazuo Sakurai, Hiroyasu Masunaga, Hiroki Ogawa, Masaki Takata

    Synchrotron Radiation News 27 (3) 19-23 2014年5月1日

    DOI: 10.1080/08940886.2014.908759  

    ISSN:0894-0886

    eISSN:1931-7344

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    Soft materials, such as polymers and fibers, are key industries in Japan and play a significant role in our daily lives [1-3]. These materials also contribute to our modern society in a wide range of applications, such as in aircrafts and automobiles, and in a diverse variety of medical, electronic, and optical devices. In the future, it is expected that polymer science and technology will continue to expand and play an important role in research related to the environment [4], energy science [5], green technology [6], and biotechnology [7]. Copyright Taylor & Francis.

  105. Microporous structures having phenylene fin: Significance of substituent groups for rotational linkers in coordination polymers

    Ryotaro Matsuda, Wataru Kosaka, Ryo Kitaura, Yoshiki Kubota, Masaki Takata, Susumu Kitagawa

    Microporous and Mesoporous Materials 189 83-90 2014年5月1日

    DOI: 10.1016/j.micromeso.2013.10.029  

    ISSN:1387-1811

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    Microporous coordination polymers having various shaped apertures were synthesized and crystallographically characterized using substituted terephthalate ligands. The substituents exert a notable influence on the channel size and shape depending on the orientations and disordering of the phenylene units such as a fin. This is a new aspect of porous coordination polymers, which would provide important information for a precise design of the micropore. © 2013 Elsevier Ltd. All rights reserved.

  106. Hierarchical dielectric orders in layered ferroelectrics Bi2SiO5

    Younghun Kim, Jungeun Kim, Akihiko Fujiwara, Hiroki Taniguchi, Sungwng Kim, Hiroshi Tanaka, Kunihisa Sugimoto, Kenichi Kato, Mitsuru Itoh, Hideo Hosono, Masaki Takata

    IUCrJ 1 160-164 2014年4月

    DOI: 10.1107/S2052252514008008  

    eISSN:2052-2525

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    © © John C.H. Spence 2014. Electric dipole engineering is now an emerging technology for high electron-mobility transistors, ferroelectric random access memory and multiferroic devices etc. Although various studies to provide insight into dipole moment behaviour, such as phase transition, order and disorder states, have been reported, macroscopic spontaneous polarization has been mainly discussed so far. Here, visualization of the electric dipole arrangement in layered ferroelectrics Bi2SiO5 by means of combined analysis of maximum entropy charge density and electrostatic potential distribution analysis based on synchrotron radiation X-ray powder diffraction data is reported. It was found that the hierarchical dipole orders, the weak-ferroelectric and ferroelectric configurations, were observed in the Bi2O2 and the SiO3 layers, respectively, and the ferrielectric configuration was realised by the interlayer interaction. This discovery provides a new method to visualize the local polarization in ferroelectric materials.

  107. Evidence of electronic polarization of the As ion in the superconducting phase of F-doped LaFeAsO

    Jungeun Kim, Akihiko Fujiwara, Tomohiro Sawada, Younghun Kim, Kunihisa Sugimoto, Kenichi Kato, Hiroshi Tanaka, Motoyuki Ishikado, Shin Ichi Shamoto, Masaki Takata

    IUCrJ 1 155-159 2014年4月

    DOI: 10.1107/S2052252514005636  

    eISSN:2052-2525

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    © © John C.H. Spence 2014. Understanding the nature of superconductivity in iron-based compounds is essential in the development of new strategies to increase T c. Using a charge density analysis based on synchrotron radiation X-ray powder diffraction data, we found that the charge carriers only accumulated in the iron layer of the superconducting phase of LaFeAsO1-x F x at low temperatures. Analysis of the electrostatic potential distribution revealed the concerted enhancement of the electronic polarization of the As ions and the carrier redistribution. This suggests that the enhanced electronic polarization of the As ion plays an important role in inducing high T c superconductivity, and that the polaron concept, which has been previously regarded as an untenable mechanism, should be reconsidered for the description of the iron-arsenide superconducting phase.

  108. Hydrogen-induced structural transformation of AuCu nanoalloys probed by synchrotron X-ray diffraction techniques

    M. Yamauchi, K. Okubo, T. Tsukuda, K. Kato, M. Takata, S. Takeda

    Nanoscale 6 (8) 4067-4071 2014年4月

    DOI: 10.1039/c3nr06327e  

    ISSN:2040-3364

    eISSN:2040-3372

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    In situ X-ray diffraction measurements reveal that the transformation of a AuCu nanoalloy from a face-centered-cubic to an L10 structure is accelerated under a hydrogen atmosphere. The structural transformation rate for the AuCu nanoalloy under hydrogen above 433 K was found to be 100 times faster than that in a vacuum, which is the first quantitative observation of hydrogen-induced ordering of nanoalloys. © the Partner Organisations 2014.

  109. Evolution of magnetic and structural transitions and enhancement of magnetocaloric effect in Fe1-xMnx V2 O4

    D. Choudhury, T. Suzuki, D. Okuyama, D. Morikawa, K. Kato, M. Takata, K. Kobayashi, R. Kumai, H. Nakao, Y. Murakami, M. Bremholm, B. B. Iversen, T. Arima, Y. Tokura, Y. Taguchi

    Physical Review B - Condensed Matter and Materials Physics 89 (10) 2014年3月31日

    DOI: 10.1103/PhysRevB.89.104427  

    ISSN:1098-0121

    eISSN:1550-235X

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    Magnetic, structural, and magnetocaloric properties have been investigated for a solid-solution system, Fe1-xMnxV2O4 (0.0≤x≤1.0) with a spinel structure. As orbital-active Fe2+ ions are partially substituted with orbital-inactive Mn2+ ions, various interactions, such as the Jahn-Teller interaction, spin-orbit coupling, and the exchange interaction, compete with each other, giving rise to a rich magnetic and structural phase diagram. The magnetocaloric effect exhibits two peaks as a function of temperature for x≤0.9, associated with a higher-temperature ferrimagnetic transition, and with a lower-temperature concomitant spin-canting and orbital-ordering (mostly lattice-structural) transition of the V site. The large magnetocaloric effect as observed in MnV2O4 can thus be attributed to the sum of the entropy changes upon the merged phase transition at TN1∼TN2. © 2014 American Physical Society.

  110. Effect of offstoichiometry on the physical properties of Sr<inf>2</inf>VO<inf>4</inf>

    Takashi Ueno, Jungeun Kim, Masaki Takata, Takuro Katsufuji

    Journal of the Physical Society of Japan 83 (3) 2014年3月15日

    DOI: 10.7566/JPSJ.83.034708  

    ISSN:0031-9015

    eISSN:1347-4073

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    ©2014 The Physical Society of Japan. We studied the physical properties of Sr2 VO4 with a K2 NiF4 structure in polycrystalline forms synthesized under various different conditions. We found that stoichiometric samples or those with nominal hole doping into the d1 state of the V ion exhibit insulating behavior with an antiferromagnetic interaction between V moments, whereas those with nominal electron doping exhibit metallic conduction and ferromagnetic interaction. A structural phase transition at Tc ∼ 100 K, which is likely to be associated with the orbital ordering of the V4+ ion, is observed only in the former sample exhibiting a sharp drop in the magnetic susceptibility at the same temperature, whereas no structural anomaly was observed for the sample exhibiting a cusp in the magnetic susceptibility at ∼50 K.

  111. Magnetic structure of the conductive triangular-lattice antiferromagnet PdCrO 2

    Hiroshi Takatsu, Gwilherm Nénert, Hiroaki Kadowaki, Hideki Yoshizawa, Mechthild Enderle, Shingo Yonezawa, Yoshiteru Maeno, Jungeun Kim, Naruki Tsuji, Masaki Takata, Yang Zhao, Mark Green, Collin Broholm

    Physical Review B - Condensed Matter and Materials Physics 89 (10) 2014年3月11日

    DOI: 10.1103/PhysRevB.89.104408  

    ISSN:1098-0121

    eISSN:1550-235X

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    We performed neutron single-crystal and synchrotron x-ray powder diffraction experiments in order to investigate the magnetic and crystal structures of the conductive layered triangular-lattice antiferromagnet PdCrO2 with a putative spin chirality, which contributes to an unconventional anomalous Hall effect. We revealed that the ground-state magnetic structure is a commensurate and nearly coplanar 120â̂̃ spin structure. The 120â̂̃ planes in different Cr layers seem to tilt with one another, leading to a small noncoplanarity. Such a small but finite noncoplanar stacking of the 120â̂̃ planes gives rise to a finite scalar spin chirality, which may be responsible for the unconventional nature of the Hall effect of PdCrO2. © 2014 American Physical Society.

  112. Solid solution alloy nanoparticles of immiscible Pd and Ru elements neighboring on Rh: Changeover of the thermodynamic behavior for hydrogen storage and enhanced co-oxidizing ability

    Kohei Kusada, Hirokazu Kobayashi, Ryuichi Ikeda, Yoshiki Kubota, Masaki Takata, Shoichi Toh, Tomokazu Yamamoto, Syo Matsumura, Naoya Sumi, Katsutoshi Sato, Katsutoshi Nagaoka, Hiroshi Kitagawa

    Journal of the American Chemical Society 136 (5) 1864-1871 2014年2月5日

    DOI: 10.1021/ja409464g  

    ISSN:0002-7863

    eISSN:1520-5126

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    PdxRu1-x solid solution alloy nanoparticles were successfully synthesized over the whole composition range through a chemical reduction method, although Ru and Pd are immiscible at the atomic level in the bulk state. From the XRD measurement, it was found that the dominant structure of PdxRu1-x changes from fcc to hcp with increasing Ru content. The structures of PdxRu1-x nanoparticles in the Pd composition range of 30-70% consisted of both solid solution fcc and hcp structures, and both phases coexist in a single particle. In addition, the reaction of hydrogen with the PdxRu1-x nanoparticles changed from exothermic to endothermic as the Ru content increased. Furthermore, the prepared PdxRu1-x nanoparticles demonstrated enhanced CO-oxidizing catalytic activity; Pd0.5Ru0.5 nanoparticles exhibit the highest catalytic activity. This activity is much higher than that of the practically used CO-oxidizing catalyst Ru and that of the neighboring Rh, between Ru and Pd. © 2014 American Chemical Society.

  113. Design and synthesis of hydroxide ion-conductive metal-organic frameworks based on salt inclusion

    Masaaki Sadakiyo, Hidetaka Kasai, Kenichi Kato, Masaki Takata, Miho Yamauchi

    Journal of the American Chemical Society 136 (5) 1702-1705 2014年2月5日

    DOI: 10.1021/ja410368j  

    ISSN:0002-7863

    eISSN:1520-5126

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    We demonstrate a metal-organic framework (MOF) design for the inclusion of hydroxide ions. Salt inclusion method was applied to an alkaline-stable ZIF-8 (ZIF = zeolitic imidazolate framework) to introduce alkylammonium hydroxides as ionic carriers. We found that tetrabutylammonium salts are immobilized inside the pores by a hydrophobic interaction between the alkyl groups of the salt and the framework, which significantly increases the hydrophilicity of ZIF-8. Furthermore, ZIF-8 including the salt exhibited a capacity for OH- ion exchange, implying that freely exchangeable OH- ions are present in the MOF. ZIF-8 containing OH- ions showed an ionic conductivity of 2.3 × 10-8 S cm-1 at 25 C, which is 4 orders of magnitude higher than that of the blank ZIF-8. This is the first example of an MOF-based hydroxide ion conductor. © 2014 American Chemical Society.

  114. High CO<inf>2</inf>/N<inf>2</inf>/O<inf>2</inf>/CO separation in a chemically robust porous coordination polymer with low binding energy

    Jingui Duan, Masakazu Higuchi, Rajamani Krishna, Tomokazu Kiyonaga, Yosuke Tsutsumi, Yohei Sato, Yoshiki Kubota, Masaki Takata, Susumu Kitagawa

    Chemical Science 5 (2) 660-666 2014年2月

    DOI: 10.1039/c3sc52177j  

    ISSN:2041-6520

    eISSN:2041-6539

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    Porous coordination polymers (PCPs), constructed from organic linkers and metal ions, can provide special pore environments for selective CO2 capture. Although many PCPs have been reported, a rational design for identifying PCPs that adsorb CO2 molecules with a low binding energy, high separation ability and high chemical stability remains a great challenge. Here, we propose and validate, experimentally and computationally, a new PCP, [La(BTN)DMF]·guest (PCP-1⊃guest), that has a large aromatic organic surface and a low binding energy for high CO2 separation from four-gas mixtures (CO2-N2-O2-CO) at ambient temperature. In addition, it shows good water and chemical stability; in particular, it is stable from pH = 2 to 12 at 100 °C, which is unprecedented for carboxylate-based PCPs. © 2014 The Royal Society of Chemistry.

  115. Transition of spherulite morphology in a crystalline/crystalline binary blend of biodegradable microbial polyesters

    Taizo Kabe, Tomoko Sato, Ken Ichi Kasuya, Takaaki Hikima, Masaki Takata, Tadahisa Iwata

    Polymer 55 (1) 271-277 2014年1月14日

    DOI: 10.1016/j.polymer.2013.11.038  

    ISSN:0032-3861

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    Crystalline/crystalline binary blend films of microbial polyesters composed of poly[(R)-3-hydroxybutyrate-co-(R)-3hydroxyhexanoate] (P(3HB-co-3HH)) and poly[(R)-3-hydroxybutyrate] (P(3HB)) that exhibit a morphological change are prepared by solvent casting. Differential scanning calorimetry measurements indicate that P(3HB-co-3HH) and P(3HB) are miscible for all blend ratios because a single glass transition temperature is observed. Polarization optical microscopy is used to investigate the transition of spherulite morphology and measure the radial growth rate of spherulites in the blend films. P(3HB-co-3HH) and P(3HB) contain positive spherulites, whereas in the binary blends, spherulite morphology changes from positive to negative. This change is related to the different growth rates of P(3HB-co-3HH) and P(3HB) lamellar crystals. Partial enzymatic degradation of the film surfaces reveals that the lamellar crystals of negative spherulites are oriented both perpendicular and parallel to the radial direction of spherulites. A new growth mechanism for spherulites in crystalline/crystalline blends is constructed from the results obtained for the blend films. © 2013 Elsevier Ltd. All rights reserved.

  116. Gate-tunable gigantic lattice deformation in VO<inf>2</inf>

    D. Okuyama, M. Nakano, S. Takeshita, H. Ohsumi, S. Tardif, K. Shibuya, T. Hatano, H. Yumoto, T. Koyama, H. Ohashi, M. Takata, M. Kawasaki, T. Arima, Y. Tokura, Y. Iwasa

    Applied Physics Letters 104 (2) 2014年1月13日

    DOI: 10.1063/1.4861901  

    ISSN:0003-6951

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    We examined the impact of electric field on crystal lattice of vanadium dioxide (VO2) in a field-effect transistor geometry by in-situ synchrotron x-ray diffraction measurements. Whereas the c-axis lattice parameter of VO2 decreases through the thermally induced insulator-to-metal phase transition, the gate-induced metallization was found to result in a significant increase of the c-axis length by almost 1% from that of the thermally stabilized insulating state. We also found that this gate-induced gigantic lattice deformation occurs even at the thermally stabilized metallic state, enabling dynamic control of c-axis lattice parameter by more than 1% at room temperature. © 2014 AIP Publishing LLC.

  117. Spin and orbital contributions to magnetically ordered moments in 5 d layered perovskite Sr2 IrO4

    S. Fujiyama, H. Ohsumi, K. Ohashi, D. Hirai, B. J. Kim, T. Arima, M. Takata, H. Takagi

    Physical Review Letters 112 (1) 2014年1月10日

    DOI: 10.1103/PhysRevLett.112.016405  

    ISSN:0031-9007

    eISSN:1079-7114

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    The ratio of orbital (L) and spin (S) contributions to the magnetically ordered moments of a 5d transition metal oxide, Sr2IrO4 was evaluated by nonresonant magnetic x-ray diffraction. We applied an improved experimental setting that minimized the experimental error, in which we varied only the linear polarization of incident x ray at a fixed scattering angle. Strong polarization dependence of the intensity of magnetic diffraction was observed, from which we conclude that the ordered moments contain substantial contribution from the orbital degree of freedom with the ratio of YLY/YSY∼5.0, evidencing the pronounced effect of spin-orbit coupling. The obtained ratio is close to, but slightly larger than the expected value for the ideal Jeff=1/2 moment of a spin-orbital Mott insulator, |YJ1/2|Lz|J1/2Y|/|YJ1/2|Sz|J1/2Y|=4, which cannot be accounted for by the redistribution of orbital components within the t2g bands associated with the elongation of the IrO6 octahedra. © 2014 American Physical Society.

  118. RISING beamline (BL28XU) for rechargeable battery analysis

    H. Tanida, K. Fukuda, H. Murayama, Y. Orikasa, H. Arai, Y. Uchimoto, E. Matsubara, T. Uruga, K. Takeshita, S. Takahashi, M. Sano, H. Aoyagi, A. Watanabe, N. Nariyama, H. Ohashi, H. Yumoto, T. Koyama, Y. Senba, T. Takeuchi, Y. Furukawa, T. Ohata, T. Matsushita, Y. Ishizawa, T. Kudo, H. Kimura, H. Yamazaki, T. Tanaka, T. Bizen, T. Seike, S. Goto, H. Ohno, M. Takata, H. Kitamura, T. Ishikawa, T. Ohta, Z. Ogumi

    Journal of Synchrotron Radiation 21 (1) 268-272 2014年1月

    DOI: 10.1107/S1600577513025733  

    ISSN:0909-0495

    eISSN:1600-5775

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    The newly installed BL28XU beamline at SPring-8 is dedicated to in situ structural and electronic analysis of rechargeable batteries. It supports the time range (1 ms to 100 s) and spatial range (1 μm to 1 mm) needed for battery analysis. Electrochemical apparatus for battery charging and discharging are available in experimental hutches and in a preparation room. Battery analysis can be carried out efficiently and effectively using X-ray diffraction, X-ray absorption fine-structure analysis and hard X-ray photoelectron spectroscopy. Here, the design and performance of the beamline are described, and preliminary results are presented.© 2014 International Union of Crystallography.

  119. Mineralogy and crystallography of some itokawa particles returned by the hayabusa asteroidal sample return mission

    Takashi Mikouchi, Mutsumi Komatsu, Kenji Hagiya, Kazumasa Ohsumi, Michael E. Zolensky, Viktor Hoffmann, James Martinez, Rupert Hochleitner, Melanie Kaliwoda, Yasuko Terada, Naoto Yagi, Masaki Takata, Wataru Satake, Yuya Aoyagi, Atsushi Takenouchi, Yuzuru Karouji, Masayuki Uesugi, Toru Yada

    Earth, Planets and Space 66 (1) 2014年

    DOI: 10.1186/1880-5981-66-82  

    ISSN:1343-8832

    eISSN:1880-5981

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    © 2014 Mikouchi et al.; licensee Springer. We studied seven Itokawa particles provided by the Japan Aerospace Exploration Agency (JAXA) as first International Announcement of Opportunity (AO) study mainly using electron and synchrotron radiation X-ray beam techniques. All the analyzed particles were collected from the first-touchdown site and composed of olivine and plagioclase with traces of Ca phosphate and chromite, and do not contain pyroxenes. Optical microscopy of these particles shows minor undulatory extinction of olivine and plagioclase, suggesting minor shock metamorphism (shock stage: S2). The electron microprobe analysis shows that olivine is Fo 70-73 and plagioclase is An 13-10 Or 5-7 . The synchrotron radiation X-ray diffraction (SR-XRD) analysis of olivine crystals gives cell dimensions of a = 4.708 to 4.779 Å, b = 10.271 to 10.289 Å, c = 6.017 to 6.024 Å, corresponding to the Fo content of Fo ~70 by Vegard's law. This composition matches the result obtained by the electron microprobe analysis. The olivine compositions of the analyzed particles are consistent with those of LL chondrites. The cell dimensions of two plagioclase crystals (a = 8.180 to 8.194 Å, b = 12.53 to 12.893 Å, c = 7.125 to 7.23 Å, α = 92.6° to 93.00°, β = 116.36° to 116.75°, γ = 90.03° to 90.17°) indicate that their equilibration temperatures are 800°C ± 10°C. This temperature is near the peak metamorphic temperature recorded by equilibrated ordinary chondrites. The size of plagioclase crystals and the homogeneity of olivine compositions indicate that their petrologic type is ≥5. We also analyzed plagioclase by SR iron X-ray absorption near-edge structure (SR-XANES) and found that its Fe 3+ /(Fe 2+ + Fe 3+ ) ratio is approximately 0.5. Such high Fe 3+ abundance indicates the formation under a relatively oxidizing environment. Thus, all these analyses have reconfirmed that the Itokawa particles returned by the Hayabusa spacecraft are very weakly shocked equilibrated LL chondrites, which matches the results of the preliminary examination team.

  120. Electronic and local crystal structures of the ZrNiSn Half-Heusler thermoelectric material

    Hidetoshi Miyazaki, Teruaki Nakano, Manabu Inukai, Kazuo Soda, Yudai Izumi, Takayuki Muro, Jungeun Kim, Masaki Takata, Masaharu Matsunami, Shin Ichi Kimura, Yoichi Nishino

    Materials Transactions 55 (8) 1209-1214 2014年

    DOI: 10.2320/matertrans.E-M2014803  

    ISSN:1345-9678

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    ©2014 The Japan Institute of Metals and Materials. We investigated the electronic and local crystal structures of the sintered half-Heusler ZrNiSn alloy by synchrotron radiation photoemission spectroscopy (SR-PES), synchrotron radiation X-ray powder diffraction (SR-XRD) measurements, and electronic band structure calculations to clarify mechanisms leading to improvements in the thermoelectric properties of materials. In contrast to the predicted semiconductor-like electronic structure, the SR-PES results show a pseudo-gap at the Fermi level, and the SR-XRD analysis reveals an interstitial Ni disorder in the half-Heusler structure. An improvement in the thermoelectric properties can be achieved by material design based on the pseudo-gap electronic structure of half-Heusler ZrNiSn-based alloys.

  121. Self-accelerating CO sorption in a soft nanoporous crystal

    Hiroshi Sato, Wataru Kosaka, Ryotaro Matsuda, Akihiro Hori, Yuh Hijikata, Rodion V. Belosludov, Shigeyoshi Sakaki, Masaki Takata, Susumu Kitagawa

    Science 343 (6167) 167-170 2014年

    DOI: 10.1126/science.1246423  

    ISSN:0036-8075

    eISSN:1095-9203

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    Carbon monoxide (CO) produced in many large-scale industrial oxidation processes is difficult to separate from nitrogen (N2), and afterward, CO is further oxidized to carbon dioxide. Here, we report a soft nanoporous crystalline material that selectively adsorbs CO with adaptable pores, and we present crystallographic evidence that CO molecules can coordinate with copper(II) ions. The unprecedented high selectivity was achieved by the synergetic effect of the local interaction between CO and accessible metal sites and a global transformation of the framework. This transformable crystalline material realized the separation of CO from mixtures with N2, a gas that is the most competitive to CO. The dynamic and efficient molecular trapping and releasing system is reminiscent of sophisticated biological systems such as heme proteins.

  122. Manipulation of discrete nanostructures by selective modulation of noncovalent forces

    Takahiro Fukino, Hyunho Joo, Yuki Hisada, Maiko Obana, Hiroshi Yamagishi, Takaaki Hikima, Masaki Takata, Norifumi Fujita, Takuzo Aida

    Science 344 (6183) 499-504 2014年

    DOI: 10.1126/science.1252120  

    ISSN:0036-8075

    eISSN:1095-9203

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    Covalent organic synthesis commonly uses the strategy of selective bond cleavage and formation. If a similar approach can be applied stepwisely to noncovalent synthesis, more exotic or challenging nanostructures might become achievable. Here, we report that ferrocene-based tetratopic pyridyl ligands, which can dynamically change their geometry by means of thermal rotation of their cyclopentadienyl rings in solution, assemble with AgBF4 into discrete metal-organic nanotubes with large and uniform diameters. The nanotubes can be cut into metal-organic nanorings through selective attenuation of the inter-nanoring interaction via ferrocene oxidation. The resultant nanorings can be transferred onto inorganic substrates electrostatically or allowed to reassemble to form the original nanotube by the reductive neutralization of their oxidized ferrocene units.

  123. First in situ NMR observation of hydrogen adsorbed inside [Cu<inf>3</inf>(btc)<inf>2</inf>] at ambient temperature and pressure

    Shun Dekura, Hirokazu Kobayashi, Guangqin Li, Ryuichi Ikeda, Yoshiki Kubota, Masaki Takata, Hiroshi Kitagawa

    Chemistry Letters 43 (8) 1363-1364 2014年

    DOI: 10.1246/cl.140404  

    ISSN:0366-7022

    eISSN:1348-0715

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    © 2014 The Chemical Society of Japan. We report the first in situ NMR observation of 2H2adsorbed inside [Cu3(btc)2] (HKUST-1; btc: benzenetricarboxylate) at ambient temperature and pressure. Hydrogen adsorption behavior was investigated by hydrogen sorption analysis and in situ solid-state 2HNMR under controlled 2H2gas pressure. Although HKUST-1 adsorbed very little amount of H2at 303 K, we could successfully observe the 2H2signal inside HKUST-1 in the NMR spectra. Furthermore, the NMR signal demonstrated that HKUST-1 interacts with H2molecules even at ambient temperature and hydrogen pressure.

  124. Coordination programming in the design of porous coordination polymers: Tuning of the electronic activity of frameworks for selective nitrogen monoxide trapping

    Wataru Kosaka, Kayo Yamagishi, Ryotaro Matsuda, Susumu Kitagawa, Masaki Takata, Hitoshi Miyasaka

    Chemistry Letters 43 (6) 890-892 2014年

    DOI: 10.1246/cl.140190  

    ISSN:0366-7022

    eISSN:1348-0715

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    A change of building block from [Ru2II, II (p-FPhCO2)4] to [Ru2II, II (4-F-2-OMe PhCO2)4] in a phenazine (phz)-bridged [Ru2II, II] chain compound led to a high selectivity toward nitrogen monoxide (NO) in the adsorption characteristics. High selectivity was observed despite the fact that electronically negative sites that enable close contact with NO molecules are not present in the pores, in contrast to [Ru2II, II (4-Cl-2-OMePhCO2)4 (phz)], which also exhibited selective NO adsorption. © 2014 The Chemical Society of Japan.

  125. A-type antiferro-orbital ordering with I4<inf>1</inf>/a symmetry and geometrical frustration in the spinel vanadate MgV<inf>2</inf>O<inf>4</inf>

    S. Niitaka, H. Ohsumi, K. Sugimoto, S. Lee, Y. Oshima, K. Kato, D. Hashizume, T. Arima, M. Takata, H. Takagi

    Physical Review Letters 111 (26) 2013年12月26日

    DOI: 10.1103/PhysRevLett.111.267201  

    ISSN:0031-9007

    eISSN:1079-7114

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    We conduct a detailed structural analysis of the S=1 pyrochlore antiferromagnet MgV2O4, which exhibits an antiferromagnetic ordering marginally at TN=40 K, triggered by a structural transition from cubic to tetragonal symmetry at TS=62 K, using high resolution synchrotron x-ray diffraction and convergent beam electron diffraction. We reveal that the tetragonal phase below TS has the symmetry of I41/a and that the distortion pattern of VO6 octahedra is consistent with A-type antiferro-orbital ordering with alternating stacking of layers with yz/xy orbital chains and zx/xy orbital chains along the tetragonal c axis. This implies that an anisotropic coupling of V moments produced by the orbital ordering below TS primarily brings about the antiferromagnetic ordering. © 2013 American Physical Society.

  126. Erratum: Two-dome structure in electron-doped iron arsenide superconductors (Nature Communications (2012) 3 (943) DOI: 10.1038/ncomms1913)

    Soshi Iimura, Satoru Matsuishi, Hikaru Sato, Taku Hanna, Yoshinori Muraba, Sung Wng Kim, Jung Eun Kim, Masaki Takata, Hideo Hosono

    Nature Communications 4 2013年12月20日

    DOI: 10.1038/ncomms4058  

    eISSN:2041-1723

  127. Propeller-shaped fused oligothiophenes: A remarkable effect of the topology of sulfur atoms on columnar stacking

    Qi Xiao, Tsuneaki Sakurai, Takahiro Fukino, Kouki Akaike, Yoshihito Honsho, Akinori Saeki, Shu Seki, Kenichi Kato, Masaki Takata, Takuzo Aida

    Journal of the American Chemical Society 135 (49) 18268-18271 2013年12月11日

    DOI: 10.1021/ja4092769  

    ISSN:0002-7863

    eISSN:1520-5126

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    Propeller-shaped regioisomers of fused oligothiophenes F9Tendo, F9Tanti, and F9Texo were successfully synthesized. DFT calculations indicated that their core parts are distorted from planarity due to intramolecular steric repulsions involving large sulfur atoms. In contrast with soft crystalline F9Tanti and F9Texo, F9Tendo self-assembles into a hexagonal columnar liquid crystal (Colh LC), displaying a clear X-ray diffraction (XRD) due to its stacked π-conjugated core. In each LC column, well-organized intermolecular S-S contacts are developed triple-helically along the columnar axis with a helical pitch of 4.04 nm. Among LC semiconductors reported to date, Colh LC F9T endo displays a top-class charge-carrier mobility (0.18 cm 2 V-1 s-1) with a distinct ambipolar character featuring well-balanced hole and electron mobilities. A thin film, prepared by mixing F9Tendo with soluble fullerene PCBM, shows a photovoltaic response, when the fullerene content is large enough to compensate a small absorptivity of F9Tendo for visible light. © 2013 American Chemical Society.

  128. Selective NO trapping in the pores of chain-type complex assemblies based on electronically activated paddlewheel-type [Ru<inf>2</inf><sup>II,II</sup>]/ [Rh<inf>2</inf><sup>II,II</sup>] dimers

    Wataru Kosaka, Kayo Yamagishi, Akihiro Hori, Hiroshi Sato, Ryotaro Matsuda, Susumu Kitagawa, Masaki Takata, Hitoshi Miyasaka

    Journal of the American Chemical Society 135 (49) 18469-18480 2013年12月11日

    DOI: 10.1021/ja4076056  

    ISSN:0002-7863

    eISSN:1520-5126

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    The design of porous materials that undergo selective adsorption of a specific molecule is a critical issue in research on porous coordination polymers or metal-organic frameworks. For the purpose of the selective capture of molecules possessing an electron-acceptor character such as nitric oxide (NO), one-dimensional chain compounds possessing a high donor character have been synthesized using 4-chloroanisate-bridged paddlewheel-type dimetal(II, II) complexes with M = Ru and Rh and phenazine (phz) as the chain linker: [M 2(4-Cl-2-OMePhCO2)4(phz)]·n(CH 2Cl2) (M = Ru, 1; Rh, 2). These compounds are isostructural and are composed of chains with a [-{M2}-phz-] repeating unit and CH2Cl2 occupying the void space between the chains. Compounds 1 and 2 change to a new phase (1-dry and 2-dry) upon evacuating the crystallization solvent (CH2Cl2) and almost lose their pores in the drying process: no void space in 1-dry and 31.8 Å3, corresponding to 2.9% of the cell volume, in 2-dry. Nevertheless, the compounds show a unique gas accommodation ability. Accompanied by a structural transformation (i.e., the first gate-opening) at low pressures of <10 kPa, both compounds show a typical physisorption isotherm for O 2 (90 K) and CO2 (195 K), with the adsorption amount of ca. 2-4 gas molecules per [M2] unit. In addition, the adsorption isotherm for NO (121 K) involves the first gate-opening followed by a second gate-opening anomaly at NO pressures of ≈52 kPa for 1-dry and ≈21 kPa for 2-dry. At the first gate-opening, the absorbed amount of NO is ca. 4 molecules per [M2] unit, and then it reaches 8.4 and 6.3 for 1-dry and 2-dry, respectively, at 95 kPa. Only the isotherm for NO exhibits hysteresis in the desorption process, and some of the NO molecules are trapped in pores even after evacuating at 121 K, although it recovers to the original dried sample on heating to room temperature. The adsorbed NO molecules accrue a significant electron donation from the host framework even in the [Rh2] derivative, indicating that such simple porous compounds with electron-donor characteristics are useful for the selective adsorption of NO. © 2013 American Chemical Society.

  129. Guest responsivity of a two-dimensional coordination polymer incorporating a cholesterol-based co-ligand

    Kazuki Kajitani, Tomomi Koshiyama, Akihiro Hori, Ryo Ohtani, Akio Mishima, Kohei Torikai, Makoto Ebine, Tohru Oishi, Masaki Takata, Susumu Kitagawa, Masaaki Ohba

    Dalton Transactions 42 (45) 15893-15897 2013年12月7日

    DOI: 10.1039/c3dt51465j  

    ISSN:1477-9226

    eISSN:1477-9234

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    To implement specific guest responsivity, a hydrophobic cholesterol-based co-ligand, cholest-5-en-3-yl-4-isonicotinate (Cholpy), was incorporated into a two-dimensional Hofmann-type Co(ii)Ni(ii) coordination polymer. The chemically programmed structure successfully demonstrated the unique guest response with remarkable chromatic changes. © 2013 The Royal Society of Chemistry.

  130. Trilayer-cubic core-shell structure of PbS/EuS nanocrystals revealed by the combination of the synchrotron small-angle X-ray scattering method and energy-dispersive X-ray spectroscopy

    Hiroyasu Masunaga, Hiroki Ogawa, Takuya Nakashima, Tsuyoshi Kawai, Takaaki Hikima, Masaki Takata, Sono Sasaki

    Dalton Transactions 42 (45) 16216-16221 2013年12月7日

    DOI: 10.1039/c3dt51710a  

    ISSN:1477-9226

    eISSN:1477-9234

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    Multilayer nanostructure analysis has been carried out for core-shell PbS/EuS nanocrystals by the combination of the synchrotron small-angle X-ray scattering (SAXS) method and energy-dispersive X-ray spectroscopy (EDS). SAXS patterns of a dilute hexane solution of the PbS/EuS nanocrystals were measured at a high signal-to-noise ratio by using synchrotron radiation. Initial structure models used for SAXS data analyses were obtained from EDS images of the particle where Eu and O atoms are localized only in the shell part of a quasi-cubic particle and, on the other hand, Pb and S atoms in the core. By simulating the intensity of SAXS using multilayer-cubic models with various core-shell electron density distributions, it was found that the particle structure was explained approximately as a trilayer-cubic model having the PbS core and the EuS/Eu2O3 shell. The diagonal length of the cubic particle was ca. 9.4 nm and the estimated thicknesses of EuS and Eu 2O3 layers in the shell were ca. 1.9 and 2.9 nm at maximum, respectively. © 2013 The Royal Society of Chemistry.

  131. High-precision spin coater for a synchrotron radiation in situ GISAXS system: For the investigation of formation mechanisms of self-assembled structures in polymer thin films

    Hiroki Ogawa, Tsukasa Miyazaki, Keisuke Shimokita, Akihiko Fujiwara, Mikihito Takenaka, Tatsuya Yamada, Yasunori Sugihara, Masaki Takata

    Journal of Applied Crystallography 46 (6) 1610-1615 2013年12月

    DOI: 10.1107/S0021889813024151  

    ISSN:0021-8898

    eISSN:1600-5767

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    A high-precision spin-coater system has been developed for the investigation of formation mechanisms of self-assembled structures in polymer thin films. The spin coater was designed to have small axial deflection (<2.6μm at the maximum speed of 2000rmin-1) during rotation in order to maintain the relative position with respect to the incident X-ray beam, and to be compact (70mm) in height to facilitate incorporation into an in situ synchrotron radiation grazing-incidence small-angle X-ray scattering (GISAXS) system. The first results of simultaneous measurements on the morphology and film thickness of a triblock copolymer with time resolution of 64ms during thin-film formation at 2000rmin-1 provide indispensable information for understanding the vertically grown lamellar structure on the film surface. © 2013 International Union of Crystallography Printed in Singapore - all rights reserved.

  132. Direct evidence of cation disorder in thermoelectric lead chalcogenides PbTe and PbS

    Sofie Kastbjerg, Niels Bindzus, Martin Søndergaard, Simon Johnsen, Nina Lock, Mogens Christensen, Masaki Takata, Mark A. Spackman, Bo Brummerstedt Iversen

    Advanced Functional Materials 23 (44) 5477-5483 2013年11月26日

    DOI: 10.1002/adfm.201300722  

    ISSN:1616-301X

    eISSN:1616-3028

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    The extraordinary thermoelectric properties of lead chalcogenides have attracted huge interest in part due to their unexpected low thermal conductivity. Here, it is shown that anharmonicity and large cation disorder are present in both PbTe and PbS, based on elaborate charge density visualization using synchrotron powder X-ray diffraction (SPXRD) data analyzed with the maximum entropy method (MEM). In both systems, the cation disorder increases with increasing temperature, whereas the Te/S anions appear to be centered on the expected lattice positions. Even at the lowest temperatures of 105 K, the lead ion is on average displaced by ≈0.2 Å from the rock-salt lattice position, creating a strong phonon scattering mechanism. These findings provide a clue to understanding the excellent thermoelectric performance of crystals with atomic disorder. The SPXRD-MEM approach can be applied in general opening up for widespread characterization of subtle structural features in crystals with unusual properties. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  133. Phase-change nanodot material for an optical memory

    Noboru Yamada, Rie Kojima, Kazuya Hisada, Takashi Mihara, Akio Tsuchino, Norihito Fujinoki, Masahiro Birukawa, Toshiyuki Matsunaga, Nobuhiro Yasuda, Yoshimitsu Fukuyama, Kiminori Ito, Yoshihito Tanaka, Shigeru Kimura, Masaki Takata

    Advanced Optical Materials 1 (11) 820-826 2013年11月

    DOI: 10.1002/adom.201300201  

    eISSN:2195-1071

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    A sputtered phase-change material, Ge10Sb90, processed into dots with a height and diameter of 50 nm, shows rapid crystallization triggered by 300 ps laser excitation. Crystallization takes place with a short time delay of approximately 70 ns for a sample with Sb seed layers. The delay becomes just 15-20 ns when a NiCr layer is provided to control the heating-cooling profile. The nanodot sample requires less energy for crystallization, with a large optical change equivalent to that of the blanket film. These results demonstrate that the nanodot phase-change material could be a possible candidate for next-generation "green" optical storage. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  134. Comparative study of X-ray charge-density data on CoSb<inf>3</inf>

    Mette Stokkebro Schmøkel, Lasse Bjerg, Finn Krebs Larsen, Jacob Overgaard, Simone Cenedese, Mogens Christensen, Georg K.H. Madsen, Carlo Gatti, Eiji Nishibori, Kunihisa Sugimoto, Masaki Takata, Bo Brummerstedt Iversen

    Acta Crystallographica Section A: Foundations of Crystallography 69 (6) 570-582 2013年11月

    DOI: 10.1107/S0108767313024458  

    ISSN:0108-7673

    eISSN:1600-5724

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    CoSb3 is an example of a highly challenging case for experimental charge-density analysis due to the heavy elements (suitability factor of ∼0.01), the perfect crystallinity and the high symmetry of the compound. It is part of a family of host-guest structures that are potential candidates for use as high-performance thermoelectric materials. Obtaining and analysing accurate charge densities of the undoped host structure potentially can improve the understanding of the thermoelectric properties of this family of materials. In a previous study, analysis of the electron density gave a picture of covalent Co-Sb and Sb-Sb interactions together with relatively low atomic charges based on state-of-the-art experimental and theoretical data. In the current study, several experimental X-ray diffraction data sets collected on the empty CoSb3 framework are compared in order to probe the experimental requirements for obtaining data of high enough quality for charge-density analysis even in the case of very unsuitable crystals. Furthermore, the quality of the experimental structure factors is tested by comparison with theoretical structure factors obtained from periodic DFT calculations. The results clearly show that, in the current study, the data collected on high-intensity, high-energy synchrotron sources and very small crystals are superior to data collected at conventional sources, and in fact necessary for a meaningful charge-density study, primarily due to greatly diminished effects of extinction and absorption which are difficult to correct for with sufficient accuracy. © 2013 International Union of Crystallography Printed in Singapore - all rights reserved.

  135. Biobased copolymers composed of l -lactic acid and side-chain-substituted lactic acids: Synthesis, properties, and solid-state structure

    Hironori Marubayashi, Shigeo Asai, Takaaki Hikima, Masaki Takata, Tadahisa Iwata

    Macromolecular Chemistry and Physics 214 (22) 2546-2561 2013年11月

    DOI: 10.1002/macp.201300406  

    ISSN:1022-1352

    eISSN:1521-3935

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    Various biobased copolyesters composed of l-lactic acid (LLA) and side-chain-substituted lactic acids (SLAs) with high molecular weight and LLA-rich composition are synthesized by direct solution polycondensation. Glycolic acid, 2-hydroxyisobutyric acid, (S)-2-hydroxy-3-methylbutanoic acid (LVOH), and (S)-2-hydroxy-4-methylpentanoic acid (LLOH) are chosen as SLAs. Wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) reveal that the substituent size of the SLAs determines whether or not SLA units are included in crystallites of the LLA sequences. Unlike poly(l-lactic acid), tensile necking is seen in the copolymers with 2 mol% LVOH and with 6 mol% LLOH. Enzymatic degradation is accelerated with increasing SLA content. Especially for 6 mol% LLOH, the SLA introduction improves both the mechanical properties and the enzymatic degradability. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  136. Anomalous lattice shrink of a single CeO<inf>2</inf>submicrometer particle in an optical trap

    Yoshimitsu Fukuyama, Nobuhiro Yasuda, Shigeru Kimura, Masaki Takata

    Journal of the Physical Society of Japan 82 (11) 2013年11月

    DOI: 10.7566/JPSJ.82.114608  

    ISSN:0031-9015

    eISSN:1347-4073

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    Anomalous lattice shrink is observed in a single submicrometer-sized CeO2particle with X-ray diffraction using an optical-trap sample holder. A CeO2particle 380 nm in size is successfully levitated with radiation pressure force exerted by counterpropagating laser beams and irradiated by a high-flux focused synchrotron radiation beam. The diffraction pattern of a single particle is consistent with that of CeO2but the lattice shrink approaches 1.22% of the lattice constant of a particle assemblage. © 2013 The Physical Society of Japan.

  137. O -phenylene octamers as surface modifiers for homeotropic columnar ordering of discotic liquid crystals

    Takashi Kajitani, Yuki Suna, Atsuko Kosaka, Terutsune Osawa, Shigenori Fujikawa, Masaki Takata, Takanori Fukushima, Takuzo Aida

    Journal of the American Chemical Society 135 (39) 14564-14567 2013年10月2日

    DOI: 10.1021/ja4087853  

    ISSN:0002-7863

    eISSN:1520-5126

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    Large-area homeotropic columnar ordering of π-conjugated discotic liquid crystals (LCs) is crucial for certain device applications but generally hard to achieve. Here we report polymeric o-phenylene octamer poly-1 and its monomer 1 as the first surface modifiers for homeotropic columnar order of a variety of discotic LCs up to a macroscopic length scale. Their octameric o-phenylene parts are known to fold helically into a cylinder that is reminiscent of a π-stacked column of discotic LCs. Through-view X-ray diffraction patterns of 1 suggested that this molecule adheres to the glass substrate and directs its cylindrical axis perpendicular to the glass surface. This "face-on" orientation likely nucleates the homeotropic columnar order of discotic LC materials. © 2013 American Chemical Society.

  138. Dynamical crossover between hyperdiffusion and subdiffusion of polymer-grafted nanoparticles in a polymer matrix

    Taiki Hoshino, Daiki Murakami, Yoshihito Tanaka, Masaki Takata, Hiroshi Jinnai, Atsushi Takahara

    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 88 (3) 2013年9月10日

    DOI: 10.1103/PhysRevE.88.032602  

    ISSN:1539-3755

    eISSN:1550-2376

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    The dynamical behavior of polystyrene-grafted silica nanoparticles dispersed in an atactic polystyrene matrix was studied using x-ray photon correlation spectroscopy. The time-autocorrelation functions were subjected to fitting analyses based on continuous-time random walk models. The nanoparticles exhibited non-Brownian behavior, and as the temperature increased, the crossover from hyperdiffusion to subdiffusion occurred at 1.25Tg, where T g is the glass transition temperature of the matrix polystyrene. Hyperdiffusive behavior is caused by the dynamical heterogeneity of the polymer matrix associated with the glass transition. When the temperature was higher than 1.25Tg, the interaction of the grafted polymers with the polymer matrix became relatively significant, and caused a dramatic change in the dynamical behavior of the nanoparticles. © 2013 American Physical Society.

  139. Electronic polarization in KNbO<inf>3</inf> visualized by synchrotron radiation powder diffraction

    Shoto Kawamura, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, Nao Taniguchi, Hiroshi Tanaka, Sachiko Maki, Masaki Takata, Satoshi Wada

    Japanese Journal of Applied Physics 52 (9 PART2) 2013年9月

    DOI: 10.7567/JJAP.52.09KF04  

    ISSN:0021-4922

    eISSN:1347-4065

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    Electron charge density studies of a potassium niobate KNbO3 perovskite-type crystal have been carried out by analyzing synchrotron radiation X-ray powder diffraction data using a combination of the Rietveld method and the maximum entropy method. The crystal structures of the cubic, tetragonal, orthorhombic, and rhombohedral phases are accurately analyzed associated with the successive ferroelectric phase transitions by taking the multicomponent structures in the ferroelectric phases into account. The electrostatic potential analyses reveal the emergence of electronic polarization arising from the anisotropic covalent bonding on the Nb and O atoms, while no significant electronic polarization is detected on the isolated K ion. Thus, the spontaneous polarization is caused by the ionic displacements of the constituent atoms and the imbalance of the hybrid atomic orbitals on the Nb-O bonding. © 2013 The Japan Society of Applied Physics.

  140. Three-dimensional near-surface imaging of chirality domains with circularly polarized X-rays

    Hiroyuki Ohsumi, Akihisa Tokuda, Soshi Takeshita, Masaki Takata, Motohiro Suzuki, Naomi Kawamura, Yusuke Kousaka, Jun Akimitsu, Taka Hisa Arima

    Angewandte Chemie - International Edition 52 (33) 8718-8721 2013年8月12日

    DOI: 10.1002/anie.201303023  

    ISSN:1433-7851

    eISSN:1521-3773

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    Imaging of chirality domains: Resonant circularly polarized X-ray diffraction distinguishes crystalline enantiomers (see picture). Control of the penetration depth and microfocusing of X-rays leads to a new visualization technique of the three-dimensional chirality-domain morphology, providing support to the increasing demand for the improvement of inorganic chiral crystal engineering. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  141. Perfectly ordered two-dimensional layer structures found in some endohedral metallofullerenes

    Sachiko Maki, Eiji Nishibori, Yutaka Kitamura, Ryo Kitaura, Masayuki Ishihara, Takayuki Aono, Shinobu Aoyagi, Masaki Takata, Makoto Sakata, Hisanori Shinohara

    Crystal Growth and Design 13 (8) 3632-3636 2013年8月7日

    DOI: 10.1021/cg400615j  

    ISSN:1528-7483

    eISSN:1528-7505

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    A two-dimensional (2D) arrangement of metallofullerenes for both M@C 82 (isomer I) (M = Y, La, Ce, Pr) and (M2C y)@C82 (isomer III) (M = Er, y = 0, 2; M = Sc, y = 2) is crystallized with a 1:2 fullerene/toluene molecular ratio. The determined crystal is a 2D layered structure, which is composed of metallofullerene layers sandwiched by the toluene layers. Although the M@C82(I) arrangement in a 1:1 crystal is almost identical to that of (M2C y)@C82(III), the M@C82(I) arrangement in a 1:2 crystal is different from (M2Cy)@C82(III). It is found that the difference of the molecular arrangement strongly correlates with an orientation of metallofullerenes in a 2D layer. Our findings suggest the existence of a subtle but important interaction between the confined atoms/molecules and the solvent molecules/toluene through the carbon cage, which leads to a guiding principle of crystallization control with a solvent ingredient for metallofullerenes. © 2013 American Chemical Society.

  142. Spin-dependent molecular orientation of O<inf>2</inf>-O<inf>2</inf> dimer formed in the nanoporous coordination polymer

    Akihiro Hori, Tatsuo C. Kobayashi, Yoshiki Kubota, Akira Matsuo, Koichi Kindo, Jungeun Kim, Kenichi Kato, Masaki Takata, Hirotoshi Sakamoto, Ryotaro Matsuda, Susumu Kitagawa

    Journal of the Physical Society of Japan 82 (8) 2013年8月

    DOI: 10.7566/JPSJ.82.084703  

    ISSN:0031-9015

    eISSN:1347-4073

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    In a model system of an O2-O2 dimer confined in the nanopores of Cu-1,4-cyclohexanedicarboxylic acid, the molecular orientation associated with the spin state was observed by precise synchrotron radiation structure analysis. The obtained charge density level structures revealed that the molecular orientation varied with increasing temperature, coupling with the spin states of the O2-O2 dimer. The magnetic properties previously reported were consistently explained by the S = 1 dimer model taking into account the molecular arrangements. The obtained gap parameters are different from those of the O2-O2 dimer confined in the nanopores of Cu-2,3-pyrazinedicarboxylate-pyrazine, which is explained by the pore deformation due to the adsorption, depending on the pore size and/or flexibility of the coordination polymer. © 2013 The Physical Society of Japan.

  143. Ferroelectricity driven by twisting of silicate tetrahedral chains

    Hiroki Taniguchi, Akihide Kuwabara, Jungeun Kim, Younghun Kim, Hiroki Moriwake, Sungwng Kim, Takuya Hoshiyama, Tsukasa Koyama, Shigeo Mori, Masaki Takata, Hideo Hosono, Yoshiyuki Inaguma, Mitsuru Itoh

    Angewandte Chemie - International Edition 52 (31) 8088-8092 2013年7月29日

    DOI: 10.1002/anie.201302188  

    ISSN:1433-7851

    eISSN:1521-3773

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    A lead-free ferroelectric: The occurrence of ferroelectricity is demonstrated in a silicate-based compound (Bi2SiO5, see picture), by direct observation of polarization switching. The mechanism of ferroelectricity in Bi2SiO5 has been studied by Raman scattering, transmission electron microscopy, X-ray powder diffraction, and first-principles calculations. The observed ferroelectricity stems from twisting of the one-dimensional SiO4 tetrahedral chain. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  144. 1,4-Bis[2-(4-ferrocenylphenyl)-ethynyl]anthraquinone from synchrotron X-ray powder diffraction

    Maki Sachiko, Eiji Nishibori, Shinobu Aoyagi, Makoto Sakata, Masaki Takata, Mio Kondo, Masaki Murata, Ryota Sakamoto, Hiroshi Nishihara

    Acta Crystallographica Section C: Crystal Structure Communications 69 (7) 696-703 2013年7月

    DOI: 10.1107/S0108270113013978  

    ISSN:0108-2701

    eISSN:1600-5759

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    The title compound, [Fe2(C5H5) 2(C40H22O2)] or 1,4-(FcPh) 2Aq [where FcPh is 2-(4-ferrocenylphenyl)ethynyl and Aq is anthraquinone], was synthesized in an attempt to obtain a new solvent-incorporating porous material with a large void space. Thermodynamic data for 1,4-(FcPh)2Aq show a phase transition at approximately 430 K. The crystal structure of solvent-free 1,4-(FcPh)2Aq was determined at temperatures of 90, 300 and 500 K using synchrotron powder diffraction data. A direct-space method using a genetic algorithm was employed for structure solution. Charge densities calculated from observed structure factors by the maximum entropy method were employed for model improvement. The final models were obtained through multistage Rietveld refinements. In both phases, the structures of which differ only subtly, the planar Aq fragments are stacked alternately in opposite orientations, forming a one-dimensional column. The FcPh arms lie between the stacks and fill the remaining space, leaving no voids. C - H⋯π interactions between the Ph and Fc fragments mediate crystal packing and stabilization. © 2013 International Union of Crystallography.

  145. Growing Partnership Asia-Oceania: Initiative by AOFSRR

    Masaki Takata

    Synchrotron Radiation News 26 (4) 39-41 2013年7月

    DOI: 10.1080/08940886.2013.812450  

    ISSN:0894-0886

    eISSN:1931-7344

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    No matter the location, it is particularly important to achieve sustainable and efficient access to a synchrotron radiation (SR) facility in order for there to be rapid progress in science and technology. Asia-Oceania is now a vibrant and thriving area in terms of making feasible a broad expansion of access to SR facility services and laying the foundation for more competitive industrial science and future economic growth to which SR science can contribute. Recently, SR facilities have started to pop up, one after another, in the Asia-Oceania region. To enhance global cooperation for SR research in this region, the AOFSRR (Asia-Oceania Forum for Synchrotron Radiation Research) was established by Australia, China, South Korea, Singapore, Taiwan, Thailand, and Japan in 2006. The objective of the AOFSRR is to organize a general framework of collaboration for the development of science and technology of mutual benefit to advancing the research goals and promoting comprehensive cooperation in synchrotron radiation research in the Asia-Oceania region. © 2013 Copyright Taylor and Francis Group, LLC.

  146. MEMによるターゲット構造可視化法の開発 : タンパク質を封じ込めた人工カプセルの合成と構造決定

    水野 伸宏, 藤田 大士, 佐藤 宗太, 熊坂 崇, 藤田 誠, 高田 昌樹

    日本結晶学会誌 55 (3) 211-217 2013年6月30日

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.55.211  

    ISSN:0369-4585

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    Proteins, sophisticated biological macromolecules, are being expected to use a wide variety of applications in the fields of industry, drug discovery and so on. However, it is now limited due to their structural instability. We first achieved to enclose the protein ubiquitin within the precisely-structured artificial capsules utilizing self-assembly process. This molecule is quite stable in various physicochemical environments. Moreover, to prove the existence of the flexible protein structure within the capsule, we developed a crystallographic method using histogram analysis of MEM electron-density(H-MED). This method might be useful to identify flexible structures which are difficult to construct atomic models.

  147. Highly enhanced thermal stability of Zn<inf>4</inf>Sb<inf>3</inf> nanocomposites

    Hao Yin, Simon Johnsen, Kasper Andersen Borup, Kenichi Kato, Masaki Takata, Bo Brummerstedt Iversen

    Chemical Communications 49 (58) 6540-6542 2013年6月25日

    DOI: 10.1039/c3cc42340a  

    ISSN:1359-7345

    eISSN:1364-548X

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    The effects of nano-sized TiO2 and ZnO ceramic inclusions on the high temperature stability of Zn4Sb3 have been studied using multi-temperature synchrotron powder X-ray diffraction. Samples with 9 nm TiO2 nanoinclusions exhibit remarkable stability after three heating cycles to 625 K. © 2013 The Royal Society of Chemistry.

  148. System of laser pump and synchrotron radiation probe microdiffraction to investigate optical recording process

    Nobuhiro Yasuda, Yoshimitsu Fukuyama, Shigeru Kimura, Kiminori Ito, Yoshihito Tanaka, Hitoshi Osawa, Toshiyuki Matsunaga, Rie Kojima, Kazuya Hisada, Akio Tsuchino, Masahiro Birukawa, Noboru Yamada, Koji Sekiguchi, Kazuhiko Fujiie, Osamu Kawakubo, Masaki Takata

    Review of Scientific Instruments 84 (6) 2013年6月

    DOI: 10.1063/1.4807858  

    ISSN:0034-6748

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    We have developed a system of laser-pump and synchrotron radiation probe microdiffraction to investigate the phase-change process on a nanosecond time scale of Ge2Sb2Te5 film embedded in multi-layer structures, which corresponds to real optical recording media. The measurements were achieved by combining (i) the pump-laser system with a pulse width of 300 ps, (ii) a highly brilliant focused microbeam with wide peak-energy width (ΔE/E ∼ 2%) made by focusing helical undulator radiation without monochromatization, and (iii) a precise sample rotation stage to make repetitive measurements. We successfully detected a very weak time-resolved diffraction signal by using this system from 100-nm-thick Ge2Sb 2Te5 phase-change layers. This enabled us to find the dependence of the crystal-amorphous phase change process of the Ge 2Sb2Te5 layers on laser power. © 2013 AIP Publishing LLC.

  149. Element-selective charge density visualization of endohedral metallofullerenes using synchrotron X-ray multi-wavelength anomalous powder diffraction data

    Sachiko Maki, Eiji Nishibori, Daisuke Kawaguchi, Makoto Sakata, Masaki Takata, Takashi Inoue, Hisanori Shinohara

    Journal of Applied Crystallography 46 (3) 649-655 2013年6月

    DOI: 10.1107/S002188981300592X  

    ISSN:0021-8898

    eISSN:1600-5767

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    An algorithm for determining the element-selective charge density has been developed using the maximum entropy method (MEM), Rietveld analysis and synchrotron X-ray multi-wavelength anomalous powder diffraction data. This article describes in detail both experimental and analytical aspects of the developed method. A structural study of yttrium mono-metallofullerene, Y@C82, 1:1 co-crystallized with toluene using the present technique is reported in order to demonstrate the applicability of the method even when only medium resolution data are available (d > 1.32Å). Element-selective MEM charge density maps, computed from synchrotron X-ray powder diffraction data collected at three distinct wavelengths around the yttrium K-absorption edge (∼0.727A), are employed for determining three crystallographic sites of the disordered yttrium. © 2013 International Union of Crystallography.

  150. Structural properties in incommensurately modulated spinel compound CuV<inf>2</inf>S<inf>4</inf>

    Shogo Kawaguchi, Hiroki Ishibashi, Naruki Tsuji, Jungeun Kim, Kenichi Kato, Masaki Takata, Yoshiki Kubota

    Journal of the Physical Society of Japan 82 (6) 2013年6月

    DOI: 10.7566/JPSJ.82.064603  

    ISSN:0031-9015

    eISSN:1347-4073

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    We have studied the incommensurate crystal structure of the spinel compound CuV2S4 at low temperatures using the synchrotron powder diffraction technique. The powder diffraction pattern at 70K shows that the splitting of the fundamental 800 reflection peak and the weak superlattice reflections with a modulation vector q ̃ 3/4[110] due to the structural phase transition at 90K were observed. It is found that the crystal structure at 70K has an orthorhombic unit cell with the superspace-group Imm2(0β0) with a modulation vector q = 0.7391(5)b*. By Rietveld analysis including the incommensurate modulation along the b-axis, large static atomic displacements were found at the positions of V atoms, suggesting that V atoms play an important role in a charge-density wave (CDW) transition. The atomic displacements indicate that V1 atoms at the 4c site form dimers along the a-axis, suggesting that a commensurate CDW forms along the a-axis. Furthermore, the V2 atoms at the 4d site tend to approach V1 dimers, giving rise to the formation of V clusters such as trimers and tetramer-like clusters. The arrangements of V clusters form a pattern along the b-axis with a period of nearly four fundamental cells, which may induce the formation of an incommensurate CDW along the b-axis. © 2013 The Physical Society of Japan.

  151. Resonant X-ray diffraction study of the strongly spin-orbit-coupled mott insulator CaIrO<inf>3</inf>

    Kenya Ohgushi, Jun Ichi Yamaura, Hiroyuki Ohsumi, Kunihisa Sugimoto, Soshi Takeshita, Akihisa Tokuda, Hidenori Takagi, Masaki Takata, Taka Hisa Arima

    Physical Review Letters 110 (21) 2013年5月24日

    DOI: 10.1103/PhysRevLett.110.217212  

    ISSN:0031-9007

    eISSN:1079-7114

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    We performed resonant x-ray diffraction experiments at the L absorption edges for the post-perovskite-type compound CaIrO3 with a (t 2g)5 electronic configuration. By observing the magnetic signals, we could clearly see that the magnetic structure was a striped ordering with an antiferromagnetic moment along the c axis and that the wave function of a t 2g hole is strongly spin-orbit entangled, the Jeff=1/2 state. The observed spin arrangement is consistent with theoretical work predicting a unique superexchange interaction in the Jeff=1/2 state and points to the universal importance of the spin-orbit coupling in Ir oxides, independent of the octahedral connectivity and lattice topology. We also propose that nonmagnetic resonant scattering is a powerful tool for unraveling an orbital state even in a metallic iridate. © 2013 American Physical Society.

  152. Strong magnetic-dielectric-lattice coupling in transition metal hydroxyhalides and ferroelectric response in rhombohedral Co<inf>2</inf>(OD) <inf>3</inf>X (X=Cl, Br)

    X. G. Zheng, M. Fujihala, S. Kitajima, M. Maki, K. Kato, M. Takata, C. N. Xu

    Physical Review B - Condensed Matter and Materials Physics 87 (17) 2013年5月13日

    DOI: 10.1103/PhysRevB.87.174102  

    ISSN:1098-0121

    eISSN:1550-235X

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    Hydroxyl salts of the type M2(OH)3X, and M(OH)X, where M represents a transition metal ion and X represents a halogen ion, widely exist as minerals and were recently reported to be geometrically frustrated magnets. Here, we report the finding of ferroelectric response in them. First, we observed strong magnetic-lattice-dielectric couplings in all of them as witnessed during their magnetic transitions at low temperatures. Secondly, we identified apparent ferroelectric responses in the deuterated hydroxyl salts of high crystal symmetries, i.e., rhombohedral Co2(OD)3Cl and Co2(OD)3Br, at high temperatures of 220-230 K through an isotope effect. The present work shows that multiferroicity may be a potentially universal phenomenon in magnetic hydroxyl salts. Meanwhile, it provides the first link between magnetic geometric frustration and hydrogen-bonded soft-mode ferroelectrics. © 2013 American Physical Society.

  153. Electronic phase transition and an anomalous ordered phase in Ba <inf>2</inf>Ti<inf>13</inf>O<inf>22</inf> with 3d1 ions on a triangle-based lattice

    K. Takayama, T. Koyama, S. Mori, K. Kato, M. Takata, J. Fujioka, Y. Tokura, J. Miyazaki, T. Katsufuji

    Physical Review Letters 110 (19) 2013年5月7日

    DOI: 10.1103/PhysRevLett.110.196405  

    ISSN:0031-9007

    eISSN:1079-7114

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    We found that Ba2Ti13O22 with Ti3 + (3d1) ions on a triangle-based lattice exhibits a phase transition at Tc∼200 K, below which the increase of electrical resistivity and decrease of magnetic susceptibility were observed. Transmission electron microscopy and optical reflectivity measurements indicate that the low-temperature phase of the present compound shares characteristics in common with a charge-density-wave state with remnant carriers, although a commensurate wave vector of the modulation and a linear temperature dependence of the magnetic susceptibility below Tc suggest an exotic ordered state. © 2013 American Physical Society.

  154. 静電ポテンシャル解析による構造物性相関研究 : ケージ内ゲスト原子の運動がもたらす熱伝導の低下の理解

    谷垣 勝己, 藤原 明比古, 杉本 邦久, 田中 宏志, 高田 昌樹

    日本結晶学会誌 55 (2) 142-147 2013年4月30日

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.55.142  

    ISSN:0369-4585

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    A successful example of visualization of quantitative structure-property relationship, relation between the anomalous distribution/dynamics of the guest atom "rattling" and the reduction of thermal conductivity in type-I clathrates, is introduced. We found that the area governed by the weakly bounded guest atom in the cage can be extracted using trace of electrostaticpotential local-minimum (EPLM). The area normalized by the size of guest atom, rattling factor, corresponds to degree of rattling, and thermal conductivity decreases with an increase of the rattling factor. The electrostatic potential distribution analysis will be a powerful tool to visualize quantitative structure-property relationship in many kinds of materials in which the novel properties originate from polarization, uneven distribution of electrons etc.

  155. Improvements and considerations for size distribution retrieval from small-angle scattering data by Monte Carlo methods

    Brian R. Pauw, Jan Skov Pedersen, Samuel Tardif, Masaki Takata, Bo B. Iversen

    Journal of Applied Crystallography 46 (2) 365-371 2013年4月

    DOI: 10.1107/S0021889813001295  

    ISSN:0021-8898

    eISSN:1600-5767

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    Monte Carlo (MC) methods, based on random updates and the trial-and-error principle, are well suited to retrieve form-free particle size distributions from small-angle scattering patterns of non-interacting low-concentration scatterers such as particles in solution or precipitates in metals. Improvements are presented to existing MC methods, such as a non-ambiguous convergence criterion, nonlinear scaling of contributions to match their observability in a scattering measurement, and a method for estimating the minimum visibility threshold and uncertainties on the resulting size distributions. Copyright © International Union of Crystallography 2013.

  156. Accurate measurements of intrinsic scattering from window materials by use of a vacuum camera

    Hiroyasu Masunaga, Kazuo Sakurai, Isamu Akiba, Kazuki Ito, Masaki Takata

    Journal of Applied Crystallography 46 (2) 577-579 2013年4月

    DOI: 10.1107/S0021889813002628  

    ISSN:0021-8898

    eISSN:1600-5767

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    The intrinsic scattering from eight window materials commonly used at synchrotron facilities has been evaluated in the range 0.07 < q < 4 nm-1 by the use of a vacuum camera. Poly(oxydiphenylene- pyromellitimide) film, a polyimide film widely used as a window material for vacuum chambers, gave rise to two peaks at q = 0.8 and 4 nm-1. Poly(ether-ether-ketone) gave no Bragg peaks, although the background scattering was relatively high over the entire q range. When natural mica, synthetic mica, quartz glass, beryllium, silicon nitride and silicon carbide were compared, synthetic mica showed the lowest scattering in the range 0.6 < q < 5 nm-1, indicating that it is the most suitable window material for this q range. Copyright © International Union of Crystallography 2013.

  157. Complex orbital state stabilized by strong spin-orbit coupling in a metallic iridium oxide IrO<inf>2</inf>

    Yasuyuki Hirata, Kenya Ohgushi, Jun Ichi Yamaura, Hiroyuki Ohsumi, Soshi Takeshita, Masaki Takata, Taka Hisa Arima

    Physical Review B - Condensed Matter and Materials Physics 87 (16) 2013年4月

    DOI: 10.1103/PhysRevB.87.161111  

    ISSN:1098-0121

    eISSN:1550-235X

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    Resonant x-ray diffraction experiments were performed for the metallic iridium oxide IrO2. We observed anisotropic tensor of susceptibility (ATS) scattering, the spectrum of which shows a sharp contrast between the L3 and L2 edges. At the L3 edge, resonance excitations were clearly observed from the core 2p orbitals to both the 5d t2g and eg orbitals. In contrast, the resonance mode associated with 5d t2g orbitals was indiscernible at the L 2 edge. This contrasting behavior indicates that Ir 5d t2g orbitals are fairly close to the Jeff=1/2 state due to the strong spin-orbit coupling in 5d transition-metal ions, as in the Mott insulator Sr2IrO4. Our results clearly demonstrate that ATS scattering is a useful probe for investigating complex orbital states in a metallic material, where novel phenomena such as the spin Hall effect are expected. © 2013 American Physical Society.

  158. Enhanced magnetization in highly crystalline and atomically mixed bcc Fe-Co nanoalloys prepared by hydrogen reduction of oxide composites

    Md Jafar Sharif, Miho Yamauchi, Shoichi Toh, Syo Matsumura, Shin Ichiro Noro, Kenichi Kato, Masaki Takata, Tatsuya Tsukuda

    Nanoscale 5 (4) 1489-1493 2013年2月21日

    DOI: 10.1039/c2nr33467d  

    ISSN:2040-3364

    eISSN:2040-3372

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    FexCo100-x nanoalloys (NAs) with 20 ≤ x ≤ 80 were prepared by hydrogen reduction of Fe-Co oxide nano-composites, which were composed of mixed phases (or domains) of Fe2O3 and CoO. In situ X-ray diffraction (XRD) measurements using synchrotron radiation clearly showed development of a solid-solution Fe-Co phase by hydrogen reduction from the oxide composites. High-resolution transmission electron microscopy (TEM), high-angle annular dark-field scanning TEM and powder XRD revealed that Fe-Co NAs form a single crystal structure and the two elements are mixed homogeneously. The saturation magnetization depends on the size and metal composition and shows the highest value (250 emu g-1) for the Fe 70Co30 NA in the size range of 30-55 nm, which is comparable to that of the Fe70Co30 bulk alloy (245 emu g-1). This high magnetization is attributable to high crystallinity and homogeneous mixing of constituent atoms, which are attained by thermal treatment of oxide phases under a hydrogen atmosphere. © 2013 The Royal Society of Chemistry.

  159. π-Conjugated nickel bis(dithiolene) complex nanosheet

    Tetsuya Kambe, Ryota Sakamoto, Ken Hoshiko, Kenji Takada, Mariko Miyachi, Ji Heun Ryu, Sono Sasaki, Jungeun Kim, Kazuo Nakazato, Masaki Takata, Hiroshi Nishihara

    Journal of the American Chemical Society 135 (7) 2462-2465 2013年2月20日

    DOI: 10.1021/ja312380b  

    ISSN:0002-7863

    eISSN:1520-5126

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    A π-conjugated nanosheet comprising planar nickel bis(dithiolene) complexes was synthesized by a bottom-up method. A liquid-liquid interfacial reaction using benzenehexathiol in the organic phase and nickel(II) acetate in the aqueous phase produced a semiconducting bulk material with a thickness of several micrometers. Powder X-ray diffraction analysis revealed that the crystalline portion of the bulk material comprised a staggered stack of nanosheets. A single-layer nanosheet was successfully realized using a gas-liquid interfacial reaction. Atomic force microscopy and scanning tunneling microscopy confirmed that the π-conjugated nanosheet was single-layered. Modulation of the oxidation state of the nanosheet was possible using chemical redox reactions. © 2013 American Chemical Society.

  160. Crystal structure and anisotropic c-f hybridization in CeT <inf>2</inf>Al<inf>10</inf> (T = Ru, Fe)

    Masafumi Sera, Daiki Tanaka, Hiroshi Tanida, Chikako Moriyoshi, Mayuko Ogawa, Yoshihiro Kuroiwa, Takashi Nishioka, Masahiro Matsumura, Jungeun Kim, Naruki Tsuji, Masaki Takata

    Journal of the Physical Society of Japan 82 (2) 2013年2月

    DOI: 10.7566/JPSJ.82.024603  

    ISSN:0031-9015

    eISSN:1347-4073

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    We have performed the investigation of the charge density distribution of CeT2Al10 (T = Ru, Fe) and the crystal structure parameters of LnT2Al10. The lattice parameters of a-, b-, and c-axes exhibit the anisotropic contraction when Ru is replaced by Fe in LnT 2Al10, different from the isotropic contraction simply expected from the smaller ionic radius of Fe than Ru. The contraction is larger in the a- and c-axes than in the b-axis. This anisotropic contraction of the YbFe2Al10-type crystal structure originates from the zigzag degree of the zigzag chain formed by T and Al bond along the a- and c-axes are larger than that along the b-axis. The lattice parameters of CeT 2Al10 (T = Ru, Fe) exhibit the anisotropic deviation from the lanthanide contraction. The deviation is largest in the a-axis and is very small in the b-axis. Both the characteristic YbFe2Al 10-type crystal structure and the anisotropic deviation towards the intermediate valence indicate that the largest c-f hybridization along the a-axis plays the important role and is associated with the unusual antiferromagnetic order in CeT2Al10 (T = Ru, Os). Copyright © 2013 The Physical Society of Japan.

  161. Modulation of the interlayer structures and magnetic behavior of 2D spin-crossover coordination polymers [Fe<sup>II</sup>(L)<inf>2</inf>Pt <sup>II</sup>(CN)<inf>4</inf>]

    Ryo Ohtani, Masashi Arai, Hisayoshi Ohba, Akihiro Hori, Masaki Takata, Susumu Kitagawa, Masaaki Ohba

    European Journal of Inorganic Chemistry (5-6) 738-744 2013年2月

    DOI: 10.1002/ejic.201201204  

    ISSN:1434-1948

    eISSN:1099-0682

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    Two 2D Hofmann-type spin-crossover coordination polymers, [Fe(stpy) 2Pt(CN) 4]·0.5MeOH (stpy = 4-styrylpyridine; 1) and [Fe(pep) 2Pt(CN) 4] {pep = 4-(2-phenylethyl)pyridine; 2}, have been prepared by using long co-ligands with different flexibilities. These compounds form 3D interdigitate structures based on 2D layers extended by Pt-CN-Fe linkages with different interlayer structures depending on the nature of the axial co-ligand. The stpy co-ligand forms one-directional π-π networks between the layers, whereas pep forms twodirectional π-π networks as a result of its perpendicularly twisted structure. Coordination polymer 1 exhibits a half-spin transition with Tc ↓ = 106 K and Tc ↑ = 110 K. In contrast, coordination polymer 2 shows a sharp, two-step spin transition in the temperature range 184-236 K. The difference in spintransition behavior is discussed in terms of the interlayer packing structure. © 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  162. Pushing X-ray electron densities to the limit: Thermoelectric CoSb <inf>3</inf>

    Mette Stokkebro Schmøkel, Lasse Bjerg, Jacob Overgaard, Finn Krebs Larsen, Georg Kent Hellerup Madsen, Kunihisa Sugimoto, Masaki Takata, Bo Brummerstedt Iversen

    Angewandte Chemie - International Edition 52 (5) 1503-1506 2013年1月28日

    DOI: 10.1002/anie.201206065  

    ISSN:1433-7851

    eISSN:1521-3773

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    A big challenge: The experimental electron density of CoSb3 was determined based on short-wavelength single-crystal synchrotron data (10 K), thereby giving a view of covalently bonded Co and Sb atoms that carry only small negative and positive charges, respectively. This result contradicts the conventional view of the electrostatic properties of the structure used in thermoelectric studies. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  163. CO<inf>2</inf> superabsorption in a paddlewheel-type Ru dimer chain compound: Gate-open performance dependent on inter-chain interactions

    Wataru Kosaka, Kayo Yamagishi, Hiroki Yoshida, Ryotaro Matsuda, Susumu Kitagawa, Masaki Takata, Hitoshi Miyasaka

    Chemical Communications 49 (16) 1594-1596 2013年1月24日

    DOI: 10.1039/c2cc36153a  

    ISSN:1359-7345

    eISSN:1364-548X

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    A porous one-dimensional coordination chain compound, [Ru2(p-F-PhCO2)4(phz)] (1′; p-F-PhCO2− = para -fluorobenzoate; phz = phenazine) derived by drying its nitrobenzene-solvated compound, specifically adsorbs CO2 at 195 K in a stepwise sorption manner. © 2013 The Royal Society of Chemistry.

  164. A structural diagnostics diagram for metallofullerenes encapsulating metal carbides and nitrides

    Sachiko Maki, Eiji Nishibori, Ikuya Terauchi, Masayuki Ishihara, Shinobu Aoyagi, Makoto Sakata, Masaki Takata, Hisashi Umemoto, Takashi Inoue, Hisanori Shinohara

    Journal of the American Chemical Society 135 (2) 918-923 2013年1月16日

    DOI: 10.1021/ja311070v  

    ISSN:0002-7863

    eISSN:1520-5126

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    Systematic structural studies of 24 different kinds of endohedral metallofullerenes, MxC2n (M = La, Y, Sc, Lu, Ti, Eu, Er, Hf, Sc3N; 34 ≤ n ≤ 43), as 1:1 cocrystals with solvent toluene molecules have been carried out using synchrotron radiation powder diffraction. Thirteen of the 24 molecular structures, including five metal carbides, one metal nitride endohedral fullerene, and one hollow fullerene, have been determined by a combination of the maximum entropy method and Rietveld refinement of the X-ray diffraction data obtained. We have found that the volume for one fullerene and one toluene molecule depends linearly on the number of carbon atoms in the fullerene cage. Fifteen different kinds of metal carbide endohedral fullerenes have been identified, which can be structurally characterized from the obtained lattice constants using only this linear dependence. The linear dependence found in the present study provides a metallofullerene diagnostics diagram that may have universal importance for structural characterization of the so-called cluster endohedral fullerenes. © 2012 American Chemical Society.

  165. Amphiphilic design of a discotic liquid-crystalline molecule for dipole manipulation: Hierarchical columnar assemblies with a 2D superlattice structure

    Ming Che Yeh, Yu Lou Su, Mei Chun Tzeng, Chi Wi Ong, Takashi Kajitani, Hideo Enozawa, Masaki Takata, Yoshiko Koizumi, Akinori Saeki, Shu Seki, Takanori Fukushima

    Angewandte Chemie - International Edition 52 (3) 1031-1034 2013年1月14日

    DOI: 10.1002/anie.201207708  

    ISSN:1433-7851

    eISSN:1521-3773

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    A liquid-crystalline dibenzophenazine that was forced to adopt a head-to-head stacking arrangement to generate a large dipole moment adapted to this stacking by hierarchical assembly into a 2D hexagonal superlattice (see picture). Thus, the net dipole and the contact area between immiscible side chains were minimized. Homeotropic alignment of the assembly on glass gave rise to directional charge transport. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  166. 28aEB-7 バナジウムスピネル酸化物FeV_2O_4の軌道希釈効果(パイロクロア系,領域8(強相関系分野:高温超伝導,強相関f電子系など))

    河口 彰吾, 石橋 広記, 三木 郁也, 金 廷恩, 加藤 健一, 高田 昌樹, 久保田 佳基

    日本物理学会講演概要集 68.2.3 584 2013年

    出版者・発行元:一般社団法人 日本物理学会

    DOI: 10.11316/jpsgaiyo.68.2.3.0_584_2  

    eISSN:2189-0803

  167. &lt;span class=&quot;aps-inline-formula&quot;&gt;&lt;math display=&quot;inline&quot;&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;-Type Antiferro-Orbital Ordering with &lt;span class=&quot;aps-inline-formula&quot;&gt;&lt;math display=&quot;inline&qu 査読有り

    Niitaka S, Ohsumi H, Sugimoto K, Lee S, Oshima Y, Kato K, Hashizume D, Arima T, Takata M, Takagi H

    Physical Review Letters 111 (26) 267201 2013年

    DOI: 10.1103/PhysRevLett.111.267201  

  168. Experimental station for multiscale surface structural analyses of soft-material films at SPring-8 via a GISWAX/GIXD/XR-integrated system

    Hiroki Ogawa, Hiroyasu Masunaga, Sono Sasaki, Shunji Goto, Takashi Tanaka, Takamitsu Seike, Sunao Takahashi, Kunikazu Takeshita, Nobuteru Nariyama, Haruhiko Ohashi, Toru Ohata, Yukito Furukawa, Tomohiro Matsushita, Yasuhide Ishizawa, Naoto Yagi, Masaki Takata, Hideo Kitamura, Atsushi Takahara, Kazuo Sakurai, Kohji Tashiro, Toshiji Kanaya, Yoshiyuki Amemiya, Kazuyuki Horie, Mikihito Takenaka, Hiroshi Jinnai, Hiroshi Okuda, Isamu Akiba, Isao Takahashi, Katsuhiro Yamamoto, Masamichi Hikosaka, Shinichi Sakurai, Yuya Shinohara, Yasunori Sugihara, Akihiko Okada

    Polymer Journal 45 (1) 109-116 2013年1月

    DOI: 10.1038/pj.2012.194  

    ISSN:0032-3896

    eISSN:1349-0540

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    To gain a better understanding of the function of soft-material thin films, one should investigate the multiscale structural information from the surface roughness down to the atomically truncated structures at microarea. To achieve such an integrated investigation, a new experimental system has been launched by coupling with the measurement techniques, which include grazing incidence small/wide-angle X-ray scattering (GISWAXS) and grazing incidence X-ray diffraction (GIXD), as well as X-ray reflectivity (XR), at the BL03XU beamline of SPring-8. The high brilliance and low divergence beam allows the surface and interface structure measurements from the angstrom to the micrometer scale using a soller-slit system for proper optimization of measurement precision. A typical structural analysis of the soft-material film was performed to evaluate the practical performance and specifications of the experimental system. © 2013 The Society of Polymer Science, Japan (SPSJ) All rights reserved.

  169. New XAFS beamline for structural and electronic dynamics of nanoparticle catalysts in fuel cells under operating conditions

    O. Sekizawa, T. Uruga, M. Tada, K. Nitta, K. Kato, H. Tanida, K. Takeshita, S. Takahashi, M. Sano, H. Aoyagi, A. Watanabe, N. Nariyama, H. Ohashi, H. Yumoto, T. Koyama, Y. Senba, T. Takeuchi, Y. Furukawa, T. Ohata, T. Matsushita, Y. Ishizawa, T. Kudo, H. Kimura, H. Yamazaki, T. Tanaka, T. Bizen, T. Seike, S. Goto, H. Ohno, M. Takata, H. Kitamura, T. Ishikawa, T. Yokoyama, Y. Iwasawa

    Journal of Physics: Conference Series 430 (1) 2013年

    DOI: 10.1088/1742-6596/430/1/012020  

    ISSN:1742-6588

    eISSN:1742-6596

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    We are currently constructing a new X-ray absorption fine structure (XAFS) beamline BL36XU at SPring-8 dedicated for the structural and electronic analysis of the dynamic events on polymer electrolyte fuel cell (PEFC) cathode catalysts for the development of next-generation PEFCs. To investigate the cathode catalyst nanoparticles in PEFCs under the operating conditions, the beamline is designed to provide time- and spatially resolved XAFS techniques having a time resolution of 100 μs, spatial resolution of 200 nm, and depth resolution of 1 μm. We report the outline and design of the new beamline.

  170. A hard X-ray nanospectroscopy station at SPring-8 BL39XU

    M. Suzuki, N. Kawamura, M. Mizumaki, Y. Terada, T. Uruga, A. Fujiwara, H. Yamazaki, H. Yumoto, T. Koyama, Y. Senba, T. Takeuchi, H. Ohashi, N. Nariyama, K. Takeshita, H. Kimura, T. Matsushita, Y. Furukawa, T. Ohata, Y. Kondo, J. Ariake, J. Richter, P. Fons, O. Sekizawa, N. Ishiguro, M. Tada, S. Goto, M. Yamamoto, M. Takata, T. Ishikawa

    Journal of Physics: Conference Series 430 (1) 2013年

    DOI: 10.1088/1742-6596/430/1/012017  

    ISSN:1742-6588

    eISSN:1742-6596

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    We upgraded the hard X-ray spectroscopy beamline BL39XU at SPring-8 by installing Kirkpatrick-Baez mirrors to equip it with submicron-focusing capability. At the new experimental end-station located 74 m from the undulator source, an X-ray nanoprobe with a size of 120 x 100 nm2 has become available at 5-16 keV. This upgrade is fully compatible with the X-ray polarization tunability and helicity-switching between right- and left-circular polarizations; these are unique features of the beamline, which is equipped with a diamond X-ray phase retarder. A spatial resolution of ≈100 nm for X-ray absorption fine structure and X-ray magnetic circular dichroism (XMCD) spectroscopy has been achieved. We show a magnetization reversal process of an individual magnetic dot in bit-patterned perpendicular recording media using element-specific XMCD magnetization measurements to demonstrate the performance of the new station.

  171. Development of fast scanning microscopic XAFS measurement system

    T. Tsuji, T. Uruga, K. Nitta, N. Kawamura, M. Mizumaki, M. Suzuki, O. Sekizawa, N. Ishiguro, M. Tada, H. Ohashi, H. Yamazaki, H. Yumoto, T. Koyama, Y. Senba, T. Takeuchi, Y. Terada, N. Nariyama, K. Takeshita, A. Fujiwara, S. Goto, M. Yamamoto, M. Takata, T. Ishikawa

    Journal of Physics: Conference Series 430 (1) 2013年

    DOI: 10.1088/1742-6596/430/1/012019  

    ISSN:1742-6588

    eISSN:1742-6596

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    We have developed a fast scanning microscopic X-ray absorption fine-structure (XAFS) measurement system using a 100-300 nm focused X-ray beam at the BL39XU nano-scale analysis station at SPring-8. This system provides two-dimensional XAFS images constructed from X-ray fluorescence (XRF) images measured by fast continuous 2-dimensional scanning at all XAFS measurement energies. High-quality XAFS spectra at each position were obtained by correcting shift in the XRF images. We applied our proposed method to measuring single catalyst particles, and succeeded in measuring the microscopic x-ray absorption near-edge structure (XANES) images that were 2-4 μm square with a spatial resolution of 300 nm.

  172. Stable delivery of nano-beams for advanced nano-scale analyses

    Haruhiko Ohashi, Hiroshi Yamazaki, Hirokatsu Yumoto, Takahisa Koyama, Yasunori Senba, Tomoyuki Takeuchi, Yasuko Terada, Motohiro Suzuki, Naomi Kawamura, Masaichiro Mizumaki, Nobuteru Nariyama, Kunikazu Takeshita, Akihiko Fujiwara, Tomoya Uruga, Shunji Goto, Masaki Yamamoto, Masaki Takata, Tetsuya Ishikawa

    Journal of Physics: Conference Series 425 (PART 5) 2013年

    DOI: 10.1088/1742-6596/425/5/052018  

    ISSN:1742-6588

    eISSN:1742-6596

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    Advanced nano-scale analyses such as X-ray absorption fine structure (XAFS), X-ray magnetic circular dichroism (XMCD) spectroscopy and X-ray fluorescence (XRF) with a ∼100 nm spatial resolution have been routinely conducted by upgrading two X-ray beamlines BL37XU and BL39XU at SPring-8. The focusing beam size can be varied from 50 nm to 2 μm and high flux achieved at 1012 photons/s/0.01% b.w. with the beam size of 300 × 300 nm2 (full width at half maximum) at 12 keV. © 2013 IOP Publishing Ltd.

  173. Improvement in stability of SPring-8 X-ray monochromators with cryogenic-cooled silicon crystals

    Hiroshi Yamazaki, Haruhiko Ohashi, Yasunori Senba, Tomoyuki Takeuchi, Yasuhiro Shimizu, Masayuki Tanaka, Yasuhisa Matsuzaki, Hikaru Kishimoto, Takanori Miura, Yasuko Terada, Motohiro Suzuki, Hiroo Tajiri, Shunji Goto, Masaki Yamamoto, Masaki Takata, Tetsuya Ishikawa

    Journal of Physics: Conference Series 425 (PART 5) 2013年

    DOI: 10.1088/1742-6596/425/5/052001  

    ISSN:1742-6588

    eISSN:1742-6596

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    SPring-8 standard double-crystal monochromators cooled with liquid nitrogen are being improved for providing a stable supply of intense nanometer-focused X-ray beams. The instability originates from the vibration and thermal deformations of the various stages of the monochromators: the former is caused by turbulent flow of the liquid nitrogen, and the latter is mainly due to unwanted cooling from the liquid nitrogen. A low-vibration flexible tube was devised to stabilize the coolant flow by covering the corrugations of the flexible tube with an alumina fiber textile. To achieve thermal insulation, we inserted a machinable ceramic block and a copper plate between the cooled crystal holder and the stages; the temperature of the copper plate was controlled to within ±0.01 °C using a sheet heater and a proportional-integral-derivative current controller. As a result, the vibration was reduced from 1 to 0.15 in terms of the misalignment angle between the two crystals, and a vertical focus size of 230 nm was achieved by demagnification projection of the real light source onto the focal plane. The angular instability due to the thermal deformation was suppressed to a rate of less than 0.2/h. Furthermore, we discuss ongoing improvements for further stabilization. © 2013 IOP Publishing Ltd.

  174. Modulation of Spin-Crossover Behavior in an Elongated and Flexible Hofmann-Type Porous Coordination Polymer

    Ryo Ohtani, Masashi Arai, Akihiro Hori, Masaki Takata, Shinji Kitao, Makoto Seto, Susumu Kitagawa, Masaaki Ohba

    Journal of Inorganic and Organometallic Polymers and Materials 23 (1) 104-110 2013年1月

    DOI: 10.1007/s10904-012-9747-z  

    ISSN:1574-1443

    eISSN:1574-1451

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    Three porous coordination polymers {Fe(dpa)[Pt(CN)4]·G·nH2O} (1-G; dpa = 1,2-di(4-pyridyl)ethane, G = dpa, bibenzyl (bbz) and stilbene (stb)) have been prepared by using a long and flexible ligand dpa. These compounds formed analogous 3-D elongated Hofmann-type frameworks based on 2-D planar layers extended by Pt-CN-Fe linkages with dpa as flexible pillar ligands. 1-dpa showed a characteristic three-step spin transition (ST) in the temperature range 180-240 K. The ST behavior was reversibly modulated by dehydration and hydration processes in keeping with the three steps. 1-bbz and 1-stb exhibited a gradual three-step ST over the range 80-200 K and an abrupt ST with Tc = 163 K. The guest-dependent cooperativity of the ST behavior is discussed by considering the flexibility of the framework and guest molecules. © 2012 Springer Science+Business Media, LLC.

  175. Thermal gradient effect on the dynamical behavior of nanoparticles observed using X-ray photon correlation spectroscopy

    Taiki Hoshino, Daiki Murakami, Kiminori Ito, Yoshihito Tanaka, Sono Sasaki, Masaki Takata, Hiroshi Jinnai, Atsushi Takahara

    Polymer Journal 45 (1) 94-99 2013年1月

    DOI: 10.1038/pj.2012.193  

    ISSN:0032-3896

    eISSN:1349-0540

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    The effects of a thermal gradient on the dynamical behavior of nanoparticles dispersed in a polymer matrix were studied using X-ray photon correlation spectroscopy. Polystyrene (PS)-grafted silica nanoparticles (SiNPs-PS), which are nanoparticles dispersed in a PS matrix controlled at temperatures above the glass transition temperature, were used in this study. Anisotropic motions of the SiNPs-PS were observed when the sample was kept in a conventional capillary tube, whereas isotropic motion was observed when the sample was kept in a newly designed cell with a low thermal flow, demonstrating the importance of the thermal gradient on the dynamical behavior of the SiNPs-PS. © 2013 The Society of Polymer Science, Japan (SPSJ) All rights reserved.

  176. Ligand-based solid solution approach to stabilisation of sulphonic acid groups in porous coordination polymer Zr <inf>6</inf>O <inf>4</inf>(OH) <inf>4</inf>(BDC) <inf>6</inf> (UiO-66)

    Maw Lin Foo, Satoshi Horike, Tomohiro Fukushima, Yuh Hijikata, Yoshiki Kubota, Masaki Takata, Susumu Kitagawa

    Dalton Transactions 41 (45) 13791-13794 2012年12月7日

    DOI: 10.1039/c2dt31195j  

    ISSN:1477-9226

    eISSN:1477-9234

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    By adopting a ligand-based solid solution approach, the sulphonic acid functional group can be successfully incorporated into a porous coordination polymer with UiO-66 structure type. Zr 6O 4(OH) 4(BDC-SO 3H) 1.1(BDC) 4.9 possesses enhanced heat of adsorption for carbon dioxide and acetone compared to Zr 6O 4(OH) 4(BDC) 6. © 2012 The Royal Society of Chemistry.

  177. Study of argon gas adsorption in ordered mesoporous mfi zeolite framework

    Hae Sung Cho, Keiichi Miyasaka, Hyungjun Kim, Yoshiki Kubota, Masaki Takata, Susumu Kitagawa, Ryong Ryoo, Osamu Terasaki

    Journal of Physical Chemistry C 116 (48) 25300-25308 2012年12月6日

    DOI: 10.1021/jp306268d  

    ISSN:1932-7447

    eISSN:1932-7455

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    An ordered mesoporous MFI zeolite material (Meso-MFI) was prepared by using CMK-type mesoporous carbons as a hard template. The Meso-MFI exhibits both structural and adsorption differences compared to the conventional bulk MFI zeolite. To study the argon (Ar) adsorption process in Meso-MFI, an in situ gas adsorption powder X-ray diffraction (XRD) analysis was performed using synchrotron X-ray source. Structural rearrangement of the mesoporous MFI zeolite upon Ar adsorption at low temperature (83 K) was intensively studied together with Ar adsorption process in Meso-MFI. We observed that a structural transition of the Meso-MFI zeolite framework from monoclinic (P21/n) to orthorhombic (Pnma) occurred at around 126 Pa at 83 K. Positions of Ar atoms are determined as a function of the Ar gas pressure through Rietveld refinement of powder XRD data. Ar atoms are observed at straight channels, sinusoidal channels, and the intersection of these channels at low pressure. As gas pressure increases, Ar atoms in the pore intersection are pulled off from the intersection toward the straight and sinusoidal channels. The pore shape of the straight channel is changed accordingly with the amount of adsorbed Ar atoms within the pores from circular to oval. These results indicate that Ar adsorption induces not only continuous rearrangement of framework atoms but also symmetry change in the Meso-MFI. A molecular simulation study combined with Rietveld refinement of in situ XRD data provided a full understanding of the adsorption process of Ar in Meso-MFI. © 2012 American Chemical Society.

  178. Weak antiferromagnetism of J <inf>eff</inf>=12 band in bilayer iridate Sr <inf>3</inf>Ir <inf>2</inf>O <inf>7</inf>

    S. Fujiyama, K. Ohashi, H. Ohsumi, K. Sugimoto, T. Takayama, T. Komesu, M. Takata, T. Arima, H. Takagi

    Physical Review B - Condensed Matter and Materials Physics 86 (17) 2012年11月16日

    DOI: 10.1103/PhysRevB.86.174414  

    ISSN:1098-0121

    eISSN:1550-235X

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    The antiferromagnetic structure of Sr 3Ir 2O 7, the bilayer analog of a spin-orbital Mott insulator Sr 2IrO 4, was revealed by resonant magnetic x-ray diffraction. Contrasting intensities of the magnetic diffraction at the Ir L III and L II edges show a J eff=1/2 character of the magnetic moment as is argued in Sr 2IrO 4. The magnitude of moment, however, was found to be smaller than that of Sr 2IrO 4 by a factor of 5 to 6, implying that Sr 3Ir 2O 7 is no longer a Mott insulator but a weak antiferromagnet. An evident change of the temperature dependence of the resistivity at T N, from almost temperature-independent resistivity to insulating, strongly suggests that the emergent weak magnetism controls the charge gap. The magnetic structure was found to be an out-of-plane collinear antiferromagnetic ordering in contrast to the in-plane canted antiferromagnetism in Sr 2IrO 4, originating from the strong bilayer antiferromagnetic coupling. © 2012 American Physical Society.

  179. X-ray photon correlation spectroscopy using a fast pixel array detector with a grid mask resolution enhancer

    Taiki Hoshino, Moriya Kikuchi, Daiki Murakami, Yoshiko Harada, Koji Mitamura, Kiminori Ito, Yoshihito Tanaka, Sono Sasaki, Masaki Takata, Hiroshi Jinnai, Atsushi Takahara

    Journal of Synchrotron Radiation 19 (6) 988-993 2012年11月

    DOI: 10.1107/S0909049512038769  

    ISSN:0909-0495

    eISSN:1600-5775

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    The performance of a fast pixel array detector with a grid mask resolution enhancer has been demonstrated for X-ray photon correlation spectroscopy (XPCS) measurements to investigate fast dynamics on a microscopic scale. A detecting system, in which each pixel of a single-photon-counting pixel array detector, PILATUS, is covered by grid mask apertures, was constructed for XPCS measurements of silica nanoparticles in polymer melts. The experimental results are confirmed to be consistent by comparison with other independent experiments. By applying this method, XPCS measurements can be carried out by customizing the hole size of the grid mask to suit the experimental conditions, such as beam size, detector size and sample-to-detector distance. © 2012 International Union of Crystallography Printed in Singapore-all rights reserved.

  180. Orbital structures in spinel vanadates AV<inf>2</inf>O<inf>4</inf> (A = Fe, Mn)

    Y. Nii, H. Sagayama, T. Arima, S. Aoyagi, R. Sakai, S. Maki, E. Nishibori, H. Sawa, K. Sugimoto, H. Ohsumi, M. Takata

    Physical Review B - Condensed Matter and Materials Physics 86 (12) 2012年9月28日

    DOI: 10.1103/PhysRevB.86.125142  

    ISSN:1098-0121

    eISSN:1550-235X

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    Spinel FeV2O4 exhibits successive structural phase transitions, reflecting the interplay between the Fe2+ (3d6) and V3+ (3d2) ions, both of which have orbital and spin degrees of freedom. The temperature-dependent orbital shapes of Fe2+ and V3 + were investigated by means of single-crystal structure analysis, and were compared with those in MnV2O4, where only the V3+ ions are Jahn-Teller active. The highest-temperature transition from the cubic to the high-temperature tetragonal phase was driven by a ferroic Fe2+ 3z2-r2 orbital order (OO). At 110 K, where the ferrimagnetic transition takes place, the magnetic order modified the orbital shape through intratomic spin-orbit coupling, causing an orthorhombic distortion. The V3 + orbital order (V-OO) contributed to the lowest temperature transition from the orthorhombic to the low-temperature tetragonal phase. The V-OO in FeV2O4 was qualitatively different from that in MnV2O4. We propose that ferro-OO contains a complex orbital in FeV2O4 in contrast to the V-OO of real orbitals observed in MnV2O4. © 2012 American Physical Society.

  181. Toward ultralow-bandgap liquid crystalline semiconductors: Use of triply fused metalloporphyrin trimer-pentamer as extra-large π-extended mesogenic motifs

    Seiya Tanaka, Tsuneaki Sakurai, Yoshihito Honsho, Akinori Saeki, Shu Seki, Kenichi Kato, Masaki Takata, Atsuhiro Osuka, Takuzo Aida

    Chemistry - A European Journal 18 (34) 10554-10561 2012年8月20日

    DOI: 10.1002/chem.201201101  

    ISSN:0947-6539

    eISSN:1521-3765

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    In contrast with their dimeric homologue, triply fused zinc porphyrin trimer-pentamer, as extra-large π-extended mesogens, assemble into columnar liquid crystals (LCs) when combined with 3,4,5-tri(dodecyloxy)phenyl side groups (3 P Zn-5 P Zn, Figure 1). Their LC mesophases develop over a wide temperature range, namely, 41-280 °C (on heating) for 5 P Zn, and all adopt an oblique columnar geometry, typically seen in columnar LC materials involving strong mesogenic interactions. These LC materials are characterized by their wide light-absorption windows from the entire visible region up to a near infrared (NIR) region. Such ultralow-bandgap LC materials are chemically stable and serve as hole transporters, in which 5 P Zn gives the largest charge carrier mobility (2.4×10 -2 cm V -1 s -1) among the series. Despite a big dimensional difference, they coassemble without phase separation, in which the resultant LC materials display essentially no deterioration of the intrinsic conducting properties. Low bandgap: Triply fused zinc porphyrin trimer-pentamers serve as extra-large π-extended mesogens for the formation of ultralow bandgap columnar liquid-crystalline (LC) semiconductors with very wide LC mesophase temperature ranges and light-absorption windows (see figure). The mobility of pentramer is roughly one order of magnitude greater than that of dimeric reference. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  182. Discotic ionic liquid crystals of triphenylene as dispersants for orienting single-walled carbon nanotubes

    Jeongho Jay Lee, Akihisa Yamaguchi, Md Akhtarul Alam, Yohei Yamamoto, Takanori Fukushima, Kenichi Kato, Masaki Takata, Norifumi Fujita, Takuzo Aida

    Angewandte Chemie - International Edition 51 (34) 8490-8494 2012年8月20日

    DOI: 10.1002/anie.201203284  

    ISSN:1433-7851

    eISSN:1521-3773

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    Orient and conduct: Triphenylene-based discotic ionic liquid crystals (ILCs) with six imidazolium ion pendants can disperse pristine single-walled carbon nanotubes (SWNTs). When the ILC is columnarly assembled, doping with SWNTs results in macroscopic homeotropic columnar orientation. Combination of shear and annealing treatments gives rise to three different orientation states, which determine the anisotropy of electrical conduction

  183. Modular design of domain assembly in porous coordination polymer crystals via reactivity-directed crystallization process

    Tomohiro Fukushima, Satoshi Horike, Hirokazu Kobayashi, Masahiko Tsujimoto, Seiji Isoda, Maw Lin Foo, Yoshiki Kubota, Masaki Takata, Susumu Kitagawa

    Journal of the American Chemical Society 134 (32) 13341-13347 2012年8月15日

    DOI: 10.1021/ja303588m  

    ISSN:0002-7863

    eISSN:1520-5126

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    The mesoscale design of domain assembly is crucial for controlling the bulk properties of solids. Herein, we propose a modular design of domain assembly in porous coordination polymer crystals via exquisite control of the kinetics of the crystal formation process. Employing precursors of comparable chemical reactivity affords the preparation of homogeneous solid-solution type crystals. Employing precursors of distinct chemical reactivity affords the preparation of heterogeneous phase separated crystals. We have utilized this reactivity-directed crystallization process for the facile synthesis of mesoscale architecture which are either solid-solution or phase-separated type crystals. This approach can be also adapted to ternary phase-separated type crystals from one-pot reaction. Phase-separated type frameworks possess unique gas adsorption properties that are not observed in single-phasic compounds. The results shed light on the importance of crystal formation kinetics for control of mesoscale domains in order to create porous solids with unique cooperative functionality. © 2012 American Chemical Society.

  184. Design of flexible lewis acidic sites in porous coordination polymers by using the viologen moiety

    Masakazu Higuchi, Kohei Nakamura, Satoshi Horike, Yuh Hijikata, Nobuhiro Yanai, Tomohiro Fukushima, Jungeun Kim, Kenichi Kato, Masaki Takata, Daisuke Watanabe, Shinji Oshima, Susumu Kitagawa

    Angewandte Chemie - International Edition 51 (33) 8369-8372 2012年8月13日

    DOI: 10.1002/anie.201203834  

    ISSN:1433-7851

    eISSN:1521-3773

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    Charged up: A novel porous coordination polymer with a charged organic surface (COS) comprising a zwitterionic organic linker, viologen, has been synthesized. The COS shows strong Lewis acidity accompanied with flexibility, and the isosteric heat of H2 adsorption is 9.5 kJ mol-1, which is comparable to that of open metal sites (OMSs). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  185. A stand-alone mesoporous crystal structure model from in situ X-ray diffraction: Nitrogen adsorption on 3 D cagelike mesoporous silica SBA-16

    Keiichi Miyasaka, Hiroko Hano, Yoshiki Kubota, Yangzheng Lin, Ryong Ryoo, Masaki Takata, Susumu Kitagawa, Alexander V. Neimark, Osamu Terasaki

    Chemistry - A European Journal 18 (33) 10300-10311 2012年8月13日

    DOI: 10.1002/chem.201201398  

    ISSN:0947-6539

    eISSN:1521-3765

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    We present a modeling scheme to analyze cagelike silica mesoporous crystals based on in situ X-ray diffraction (XRD) data collected during gas adsorption-desorption (physisorption) processes. Nitrogen physisorption on a silica mesoporous crystal of SBA-16 was directly monitored by using synchrotron in situ powder XRD measurements conducted at SPring-8. SBA-16 is a well-ordered mesoporous silica in which three-dimensional interconnected cagelike primary mesopores are located at the body-centered cubic lattice points. In addition, the surrounding silica matrix contains random microporous and mesoporous intrawall porosities that are significantly influential to the diffusion properties, and thus important to be quantified for this media. The in situ XRD data exhibits seven Bragg reflections throughout the measurements, and the present method allows one to obtain the maximal and stand-alone information about the pore structure (for example, the mesopore size, the matrix density, the intrawall porosity, and pore surface roughness) together with the nitrogen film evolution in the primary mesopores and the intrawall pore-filling in the silica matrix. We furthermore observe a macroscopic amount of nitrogen adsorbed assuming the density of the fluid, and confirm that the XRD "isotherm" recalculated from the analysis result is consistent with the conventional nitrogen isotherm on a semi-quantitative level; however, these results suggest that the intrawall pores would have a greater contribution to the adsorption than considered based on the conventional isotherm analyses. The present method is readily extendable to any ordered mesopores wrapped by the wall matrix containing a certain intrawall porosity. Trapped in a cage: From gas adsorption in situ X-ray diffraction analysis, a self-consistent modeling scheme was established dedicated to the pore wall structure of ordered large cagelike mesopores surrounded by a silica matrix that contains the intrawall random porosity. From limited diffraction information from SBA-16, nitrogen fluid evolution in mesopores and the intrawall pore filling in the matrix are systematically traced, and eventually essential pore structure parameters are successfully quantified. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  186. Wide-range 2D lattice correlation unveiled for columnarly assembled triphenylene hexacarboxylic esters

    Terutsune Osawa, Takashi Kajitani, Daisuke Hashizume, Hiroyuki Ohsumi, Sono Sasaki, Masaki Takata, Yoshiko Koizumi, Akinori Saeki, Shu Seki, Takanori Fukushima, Takuzo Aida

    Angewandte Chemie - International Edition 51 (32) 7990-7993 2012年8月6日

    DOI: 10.1002/anie.201203077  

    ISSN:1433-7851

    eISSN:1521-3773

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    Dipole bridge: Liquid-crystalline (LC) triphenylenes (see picture) self-assemble columnarly into a hexagonal geometry with a wide-range 2D lattice correlation, for which distal and proximal dipole-dipole interactions are considered responsible. By virtue of the strong intercolumnar interaction, the LC columns of the triphenylene can spontaneously align homeotropically on the 12 different substrates examined (POM=polarized optical microscopy). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  187. Nanosize-induced drastic drop in equilibrium hydrogen pressure for hydride formation and structural stabilization in Pd-Rh solid-solution alloys

    Hirokazu Kobayashi, Hitoshi Morita, Miho Yamauchi, Ryuichi Ikeda, Hiroshi Kitagawa, Yoshiki Kubota, Kenichi Kato, Masaki Takata, Shoichi Toh, Syo Matsumura

    Journal of the American Chemical Society 134 (30) 12390-12393 2012年8月1日

    DOI: 10.1021/ja305031y  

    ISSN:0002-7863

    eISSN:1520-5126

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    We have synthesized and characterized homogeneous solid-solution alloy nanoparticles of Pd and Rh, which are immiscible with each other in the equilibrium bulk state at around room temperature. The Pd-Rh alloy nanoparticles can absorb hydrogen at ambient pressure and the hydrogen pressure of Pd-Rh alloys for hydrogen storage is dramatically decreased by more than 4 orders of magnitude from the corresponding pressure in the metastable bulk state. The solid-solution state is still maintained in the nanoparticles even after hydrogen absorption/desorption, in contrast to the metastable bulks which are separated into Pd and Rh during the process. © 2012 American Chemical Society.

  188. Effect of functional groups in MIL-101 on water sorption behavior

    George Akiyama, Ryotaro Matsuda, Hiroshi Sato, Akihiro Hori, Masaki Takata, Susumu Kitagawa

    Microporous and Mesoporous Materials 157 89-93 2012年7月15日

    DOI: 10.1016/j.micromeso.2012.01.015  

    ISSN:1387-1811

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    Four MIL-101-type porous coordination polymers were synthesized containing different substituents (-H, -NO 2, -NH 2, -SO 3H) in the ligand and their water sorption properties were investigated. All of the compounds adsorbed huge amounts of water (ca. 0.8-1.2 g g -1) and the adsorbed water can be released at relatively low temperatures (ca. 353 K). In addition, the trapping pressure of water adsorption was found to be controlled by changing the substituents, varying the hydrophobicity of the functional groups. © 2011 Elsevier Inc. All rights reserved.

  189. Two-dimensional heisenberg behavior of J <inf>eff</inf>=1/2 isospins in the paramagnetic state of the spin-orbital mott insulator Sr <inf>2</inf>IrO <inf>4</inf>

    S. Fujiyama, H. Ohsumi, T. Komesu, J. Matsuno, B. J. Kim, M. Takata, T. Arima, H. Takagi

    Physical Review Letters 108 (24) 2012年6月15日

    DOI: 10.1103/PhysRevLett.108.247212  

    ISSN:0031-9007

    eISSN:1079-7114

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    The dynamical correlations of J eff=1/2 isospins in the paramagnetic state of spin-orbital Mott insulator Sr 2IrO 4 were revealed by resonant magnetic x-ray diffuse scattering. We found a two-dimensional antiferromagnetic fluctuation with a large in-plane correlation length exceeding 100 lattice spacings at even 20 K above the magnetic ordering temperature. In marked contrast to the naive expectation of the strong magnetic anisotropy associated with an enhanced spin-orbit coupling, we discovered an isotropic isospin correlation that is well described by the two-dimensional S=1/2 quantum Heisenberg model. The estimated antiferromagnetic coupling constant as large as J∼0.1eV that is comparable to the small Mott gap (<0.5eV) points out the weak and marginal Mott character of this spin-orbital entangled system. © 2012 American Physical Society.

  190. Tetrahedral magnetic order and the metal-insulator transition in the pyrochlore lattice of Cd <inf>2</inf>Os <inf>2</inf>O <inf>7</inf>

    J. Yamaura, K. Ohgushi, H. Ohsumi, T. Hasegawa, I. Yamauchi, K. Sugimoto, S. Takeshita, A. Tokuda, M. Takata, M. Udagawa, M. Takigawa, H. Harima, T. Arima, Z. Hiroi

    Physical Review Letters 108 (24) 2012年6月13日

    DOI: 10.1103/PhysRevLett.108.247205  

    ISSN:0031-9007

    eISSN:1079-7114

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    Cd 2Os 2O 7 shows a peculiar metal-insulator transition at 227 K with magnetic ordering in a frustrated pyrochlore lattice, but its magnetic structure in the ordered state and the transition origin are yet uncovered. We observed a commensurate magnetic peak by resonant x-ray scattering in a high-quality single crystal. X-ray diffraction and Raman scattering experiments confirmed that the transition is not accompanied with any spatial symmetry breaking. We propose a noncollinear all-in-all-out spin arrangement on the tetrahedral network made of Os atoms. Based on this we suggest that the transition is not caused by the Slater mechanism as believed earlier but by an alternative mechanism related to the formation of the specific tetrahedral magnetic order on the pyrochlore lattice in the presence of strong spin-orbit interactions. © 2012 American Physical Society.

  191. The roles of the Ge-Te core network and the Sb-Te pseudo network during rapid nucleation-dominated crystallization of amorphous Ge <inf>2</inf>Sb <inf>2</inf>Te <inf>5</inf>

    Koji Ohara, Lászlõ Temleitner, Kunihisa Sugimoto, Shinji Kohara, Toshiyuki Matsunaga, Lászlõ Pusztai, Masayoshi Itou, Hiroyuki Ohsumi, Rie Kojima, Noboru Yamada, Takeshi Usuki, Akihiko Fujiwara, Masaki Takata

    Advanced Functional Materials 22 (11) 2251-2257 2012年6月6日

    DOI: 10.1002/adfm.201102940  

    ISSN:1616-301X

    eISSN:1616-3028

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    Ge 2Sb 2Te 5 (GST) has demonstrated its outstanding importance among rapid phase-change (PC) materials, being applied for optical and electrical data storage for over three decades. The mechanism of nanosecond phase change in GST, which is vital for its application, has long been disputed: various, quite diverse scenarios have been proposed on the basis of various experimental and theoretical approaches. Nevertheless, one central question still remains unanswered: why is amorphous GST stable at room temperature for long time while it can rapidly transform to the crystalline phase at high temperature? Here it is revealed for the first time, by modelling the amorphous structure based on synchrotron radiation anomalous X-ray scattering data, that germanium and tellurium atoms form a "core" Ge-Te network with ring formation. It is also suggested that the Ge-Te network can stabilize the amorphous phase at room temperature and can persist in the crystalline phase. On the other hand, antimony does not contribute to ring formation but constitutes a "pseudo" network with tellurium, in which the characteristic Sb-Te distance is somewhat longer than the covalent Sb-Te bond distance. This suggests that the Sb-Te pseudo network may act as a precursor to forming critical nuclei during the crystallization process. The findings conclude that the Ge-Te core network is responsible for the outstanding stability and rapid phase change of the amorphous phase while the Sb-Te pseudo network is responsible for triggering critical nucleation. In the rapid phase change material Ge 2Sb 2Te 5, the Ge-Te core network stabilizes the amorphous phase at room temperature. This network is also present in the crystalline phase, thus enabling rapid phase change. The Sb-Te pseudo network, defined by atoms that are somewhat further apart than the covalent Sb-Te distance, is responsible for triggering critical nucleation. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  192. Comment on "new structural picture of the Ge <inf>2</inf>Sb <inf>2</inf>Te <inf>5</inf> phase-change alloy"

    P. Fons, A. V. Kolobov, J. Tominaga, S. Kohara, M. Takata, T. Matsunaga, N. Yamada, S. Bokoch

    Physical Review Letters 108 (23) 2012年6月4日

    DOI: 10.1103/PhysRevLett.108.239603  

    ISSN:0031-9007

    eISSN:1079-7114

  193. Emergent phenomena in perovskite-type manganites

    Y. Taguchi, H. Sakai, D. Okuyama, S. Ishiwata, J. Fujioka, T. Fukuda, D. Hashizume, F. Kagawa, Y. Takahashi, R. Shimano, Y. Tokunaga, Y. Kaneko, A. Nakao, H. Nakao, Y. Murakami, K. Sugimoto, M. Takata, K. Yamauchi, S. Picozzi, A. Q.R. Baron, T. Arima, Y. Tokura

    Physica B: Condensed Matter 407 (11) 1685-1688 2012年6月1日

    DOI: 10.1016/j.physb.2012.01.006  

    ISSN:0921-4526

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    Perovskite-type manganites exhibit various interesting phenomena arising from complex interplay among spin, charge, orbital, and lattice degrees of freedom. One such example is the keen competition between phases with different spin/charge/orbital orders. Keen competition between antiferromagnetic metal and orbital-ordered insulator is found in the slightly electron-doped regime near Mn 4 state which is stabilized by the high oxygen-pressure condition. Another one is the emergence of ferroelectricity either induced by the magnetic ordering or independently of the magnetic ordering. As the respective examples, perovskite-type YMnO 3 and Sr 1-xBa xMnO 3 are discussed. In the YMnO 3, the ferroelectric lattice distortion associated with the E-type spin order is observed for the first time. Displacement-type ferroelectricity with off-center magnetic ions is discovered for Sr 0.5Ba 0.5MnO 3, which shows both large polarization value and strong coupling between ferroelectricity and magnetism. © 2012 Elsevier B.V. All rights reserved.

  194. A long-lived photo-induced metastable state of linkage isomerization accompanied with a spin transition

    Chou Fu Sheu, Che Hsiu Shih, Kunihisa Sugimoto, Bing Ming Cheng, Masaki Takata, Yu Wang

    Chemical Communications 48 (46) 5715-5717 2012年5月14日

    DOI: 10.1039/c2cc31326j  

    ISSN:1359-7345

    eISSN:1364-548X

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    In addition to the generally observed LIESST phenomenon, polymorph D of trans-[FeII(abpt)2(NCS)2] exhibits a long-lived photo-induced metastable state through linkage isomerization accompanied with a spin crossover transition, which is stable up to 108 K. © 2012 The Royal Society of Chemistry.

  195. Refinement of position resolution in two-dimensional X-ray detector based on μ-PIC gaseous detector

    K. Hattori, J. D. Parker, C. Ida, K. Ito, H. Kubo, K. Miuchi, T. Tanimori, M. Takata

    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 674 1-7 2012年5月11日

    DOI: 10.1016/j.nima.2012.01.043  

    ISSN:0168-9002

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    We have successfully refined the position resolution of a two-dimensional X-ray photon-counting detector based on the micro-pixel gas chamber (μ-PIC) by measuring the charge distribution of an X-ray interaction without the use of analog-to-digital converters (ADCs). By updating the logic of the Field Programmable Gate Arrays (FPGAs) included in the data acquisition system, we were able to acquire the pulse widths, or time-above-threshold of the μ-PIC signals, by measuring both the leading and trailing edges of the digital signals. By using the measured widths to estimate the peak of the charge distribution, the position resolution of our detector was improved to σ=93.3±2.8μm from a value of σ=229.5±6.8μm found using the FPGA logic of the previous system. This represents an improvement of nearly 60%. © 2012 Elsevier B.V. All rights reserved.

  196. Ferroelectric columnar liquid crystal featuring confined polar groups within core-shell architecture

    Daigo Miyajima, Fumito Araoka, Hideo Takezoe, Jungeun Kim, Kenichi Kato, Masaki Takata, Takuzo Aida

    Science 336 (6078) 209-213 2012年4月

    DOI: 10.1126/science.1217954  

    ISSN:0036-8075

    eISSN:1095-9203

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    Ferroelectric liquid crystals are materials that have a remnant and electrically invertible polar order. Columnar liquid crystals with a ferroelectric nature have potential use in ultrahigh-density memory devices, if electrical polarization occurs along the columnar axis. However, columnar liquid crystals having an axial nonzero polarization at zero electric field and its electrical invertibility have not been demonstrated. Here, we report a ferroelectric response for a columnar liquid crystal adopting a core-shell architecture that accommodates an array of polar cyano groups confined by a hydrogen-bonded amide network with an optimal strength. Under an applied electric field, both columns and core cyano groups align unidirectionally, thereby developing an extremely large macroscopic remnant polarization.

  197. Quantitative relation between structure and thermal conductivity in type-I clathrates X <inf>8</inf>Ga <inf>16</inf>Ge <inf>30</inf> (X = Sr, Ba) based on electrostatic-potential analysis

    Akihiko Fujiwara, Kunihisa Sugimoto, Che Hsiu Shih, Hiroshi Tanaka, Jun Tang, Yoichi Tanabe, Jingtao Xu, Satoshi Heguri, Katsumi Tanigaki, Masaki Takata

    Physical Review B - Condensed Matter and Materials Physics 85 (14) 2012年4月

    DOI: 10.1103/PhysRevB.85.144305  

    ISSN:1098-0121

    eISSN:1550-235X

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    In order to quantitatively characterize the effect of motion of the guest atom in type-I clathrates X 8Ga 16Ge 30 (X = Sr, Ba) on thermal conductivity, electrostatic potential in the crystal was visualized by synchrotron radiation x-ray diffraction. The obtained electrostatic potential clearly exhibited structural aspects of the guest atom, rattling, which is considered as a cause of suppression of thermal conductivity κ. The parameterized degree of rattling "rattling factor," f R, being defined as a volume ratio of the electrostatic interaction region of the guest atom to the spherical volume estimated by the covalent radius of the guest atom, was found to well classify κ. The κ monotonously decreases with increasing the f R. Consequently, f R was judged as a better criterion to explore high-performance thermoelectric system of the clathrates. © 2012 American Physical Society.

  198. Physical and structural effects of adding ultrahigh-molecular-weight poly[(R)-3-hydroxybutyrate] to wild-type poly[(R)-3-hydroxybutyrate]

    Taizo Kabe, Takeharu Tsuge, Ken Ichi Kasuya, Akio Takemura, Takaaki Hikima, Masaki Takata, Tadahisa Iwata

    Macromolecules 45 (4) 1858-1865 2012年2月28日

    DOI: 10.1021/ma202285c  

    ISSN:0024-9297

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    Blend films containing wild-type poly[(R)-3-hydroxybutyrate]] (P(3HB)) and ultrahigh-molecular-weight P(3HB) (UHMW-P(3HB)) (compositions of 5/95 and 10/90 w/w) were prepared by solvent-casting and subsequent cold-drawing. The thermal properties, crystallization behavior, mechanical properties, and highly ordered structure of the blend films were analyzed by differential scanning calorimetry, polarized optical microscopy, a tensile test, and wide- and small-angle X-ray diffraction measurements with synchrotron radiation. The maximum radial growth rate of spherulites and corresponding temperature were identical for films of different composition. However, the half-time of crystallization of the blend films was shorter than that of P(3HB) because UHMW-P(3HB) behaves as a nucleating agent. The tensile strength, Young's modulus, and elongation at break of a 5/95 blend film after cold-drawing to 12 times of the original length were 242 MPa, 1.50 GPa, and 88%, respectively, which are higher than those of an UHMW-P(3HB) cold-drawn film and similar to those of common plastic films as poly(ethylene terephthalate). The wide-angle X-ray diffraction results indicated that the cold-drawn films with high tensile strength contained both 2 1 helix (α-form) and planar zigzag (β-form) conformations. Addition of a small amount of UHMW-P(3HB) to P(3HB) caused the β-form to appear in blend films at a high drawing ratio. A mechanism for forming β-form crystals in the blend films is proposed. Enzymatic degradation of the cold-drawn blend films is demonstrated using polyhydroxybutyrate depolymerase, suggesting that the rate of enzymatic degradation can be controlled by addition of UHMW-P(3HB). © 2012 American Chemical Society.

  199. Segregated and alternately stacked donor/acceptor nanodomains in tubular morphology tailored with zinc porphyrin-C <inf>60</inf> amphiphilic dyads: Clear geometrical effects on photoconduction

    Richard Charvet, Yohei Yamamoto, Takayuki Sasaki, Jungeun Kim, Kenichi Kato, Masaki Takata, Akinori Saeki, Shu Seki, Takuzo Aida

    Journal of the American Chemical Society 134 (5) 2524-2527 2012年2月8日

    DOI: 10.1021/ja211334k  

    ISSN:0002-7863

    eISSN:1520-5126

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    Amphiphilic zinc porphyrin (P Zn; electron donor, D)-fullerene (C 60; electron acceptor, A) dyads 2 and 3, bearing an identical hydrophilic wedge with triethylene glycol chains but different linkers between the P Zn and C 60 units, self-assemble into nanotubes with essentially different dimensional and geometrical features from one another. The nanotube from dyad 2 with an ester linker consists of a bilayer wall formed with coaxially segregated D and A nanodomains along the tube axis (coaxial D-A heterojunction), thereby displaying explicit photoconductivity with ambipolar carrier transport properties. In contrast, the nanotube from dyad 3 with a rigid arylacetylene linker consists of a monolayer wall with an alternate geometry of D/A stacking, resulting in poor photoconducting outputs. Such a geometrical difference also significantly affects the photovoltaic properties. © 2012 American Chemical Society.

  200. Structural analysis and superconductivity of CeFeAsO <inf>1-x</inf>H <inf>x</inf>

    Satoru Matsuishi, Taku Hanna, Yoshinori Muraba, Sung Wng Kim, Jung Eun Kim, Masaki Takata, Shin Ich Shamoto, Ronald I. Smith, Hideo Hosono

    Physical Review B - Condensed Matter and Materials Physics 85 (1) 2012年1月19日

    DOI: 10.1103/PhysRevB.85.014514  

    ISSN:1098-0121

    eISSN:1550-235X

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    We performed the neutron powder diffraction (NPD) and synchrotron x-ray diffraction measurements on CeFeAsO 1-x(D,H) x (x = 0.0 - 0.48) as a representative of 1111-type family of iron-based superconductors LnFeAsO 1-xH x (Ln = lanthanoid). Deuterated and hydrogenated samples (CeFeAsO 1-xD x and CeFeAsO 1-xH x) were synthesized by the solid-state reaction of a metal oxide, arsenides, and a hydride and a deuteride source under an applied pressure of 2 GPa. No distinct differences were found between the structural and superconducting properties of the hydride and deuteride samples. Rietveld analyses of the NPD patterns demonstrated that deuterium exclusively substitutes on the oxygen sites in the 1111-type structures according to the nominal composition. Bulk superconductivity was observed over a wide x region (0.1 < x < 0.4) and the superconducting dome had a rather flat shape with a maximum T c = 47 K at around x = 0.25. It was concluded from density functional theory calculations and comparison with the superconducting dome of the fluorine-substituted system that the charge state of the hydrogen substituting the oxygen sites was -1. The relationship between the lattice parameter a and T c in our samples prepared from metal hydrides is almost the same as that reported previously for samples prepared from cerium hydroxide. These results strongly suggest that H - ions exclusively occupy the oxygen sites in both samples, regardless of the hydrogen species in the starting material. © 2012 American Physical Society.

  201. Evaluation of the influence of ionization states and spacers in the thermotropic phase behaviour of amino acid-based cationic lipids and the transfection efficiency of their assemblies

    Satya Ranjan Sarker, Satoshi Arai, Motohide Murate, Hiroshi Takahashi, Masaki Takata, Toshihide Kobayashi, Shinji Takeoka

    International Journal of Pharmaceutics 422 (1-2) 364-373 2012年1月17日

    DOI: 10.1016/j.ijpharm.2011.10.044  

    ISSN:0378-5173

    eISSN:1873-3476

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    The influence of both the ionization states and the hydrocarbon chain spacer of a series of amino acid-based cationic lipids was evaluated in terms of gene delivery efficiency and cytotoxicity to the COS-7 cell line and compared with that of Lipofectamine™ 2000. We synthesized a series of amino acid-based cationic lipids with different ionization states (i.e., -NH 2, -NH 3+Cl - or -NH 3+TFA -) in the lysine head group and different hydrocarbon chain spacers (i.e., 0, 3, 5 or 7 carbon atoms) between the hydrophilic head group and hydrophobic moieties. In the 3-carbon series, the cationic assemblies formed a micellar structure in the presence of -NH 3+Cl - and a vesicular structure both in the presence of -NH 2 and -NH 3+TFA -. Differential scanning calorimetry (DSC) data revealed a significantly lower (8.1°C) gel-to-liquid crystalline phase transition temperature for cationic assemblies bearing -NH 3+TFA - when compared to their -NH 2 counterparts. Furthermore, the zeta potential of cationic assemblies having -NH 3+TFA - in the hydrophilic head group was maximum followed by -NH 3+Cl - and -NH 2 irrespective of their hydrocarbon chain spacer length. The gene delivery efficiency in relation to the ionization states of the hydrophilic head group was as follows: -NH 3+TFA - > -NH 3+Cl - > -NH 2. © 2011 Elsevier B.V.

  202. Multistep crystallization process involving sequential formations of density fluctuations, "intermediate structures", and lamellar crystallites: Poly(3-hydroxybutyrate) As investigated by time-resolved synchrotron SAXS and WAXD

    Longhai Guo, Nicolas Spegazzini, Harumi Sato, Takeji Hashimoto, Hiroyasu Masunaga, Sono Sasaki, Masaki Takata, Yukihiro Ozaki

    Macromolecules 45 (1) 313-328 2012年1月10日

    DOI: 10.1021/ma201475t  

    ISSN:0024-9297

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    We explored the isothermal crystallization process of poly(3- hydroxybutyrate) by means of simultaneous measurements of time-resolved wide-angle X-ray diffraction (tr-WAXD) and small-angle X-ray scattering (tr-SAXS) methods. The tr-WAXD analyses involve not only (1) a precise analysis of the integral widths but also the analyses such as (2) two-dimensional correlation spectroscopy (2D-COS) and (3) multivariate curve resolution-alternating least squares (MCR-ALS). The tr-SAXS analyses involve not only (4) the conventional one-dimensional correlation function analysis but also the analyses such as (5) 2D-COS between tr-SAXS and tr-WAXD profiles and (6) 2D-COS of tr-SAXS profiles themselves. These analyses elucidated a multistep crystallization process as classified by region I to III in order of the increasing time. In region I, the density fluctuations are first built up in the amorphous matrix, and then the density-rich regions locally develop "intermediate structures" having the mesomorphic orders between pure amorphous melts and pure crystals [lamellar crystallites (LC)], which then grow into layers of the intermediate structures [defined as mesomorphic layers (ML)] with the long spacings. These results were elucidated by analysis (5) and (6). In region II, LC start to be created from ML, which was elucidated by analysis (1) to (4), and both of the weight fractions of ML (X inter) and LC (X crys) increase with time [analysis (3)]. In region III, X inter and X crys decreases and increases with time, respectively [analysis (3)], because the transformation form ML to LC dominates the transformation from the density fluctuations to ML. The WAXD profiles due to ML in region I was identified by analysis (1), while those in regions II and III were identified by analysis (3). © 2011 American Chemical Society.

  203. Two-dome structure in electron-doped iron arsenide superconductors

    Soshi Iimura, Satoru Matuishi, Hikaru Sato, Taku Hanna, Yoshinori Muraba, Sung Wng Kim, Jung Eun Kim, Masaki Takata, Hideo Hosono

    Nature Communications 3 2012年

    DOI: 10.1038/ncomms1913  

    eISSN:2041-1723

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    Iron arsenide superconductors based on the material LaFeAsO 1-x F x are characterized by a two-dimensional Fermi surface (FS) consisting of hole and electron pockets yielding structural and antiferromagnetic transitions at x=0. Electron doping by substituting O 2- with F - suppresses these transitions and gives rise to superconductivity with a maximum T c of 26 K at x=0.1. However, the over-doped region cannot be accessed due to the poor solubility of F - above x=0.2. Here we overcome this problem by doping LaFeAsO with hydrogen. We report the phase diagram of LaFeAsO 1-x H x (x<0.53) and, in addition to the conventional superconducting dome seen in LaFeAsO 1-x F x, we find a second dome in the range 0.21<x<0.53, with a maximum T c of 36 K at x=0.3. Density functional theory calculations reveal that the three Fe 3d bands (xy, yz and zx) become degenerate at x=0.36, whereas the FS nesting is weakened monotonically with x. These results imply that the band degeneracy has an important role to induce high T c. © 2012 Macmillan Publishers Limited. All rights reserved.

  204. Structural analysis of spinel compound CuV<inf>2</inf>S<inf>4</inf> with incommensurate charge-density wave

    Shogo Kawaguchi, Yoshiki Kubota, Naruki Tsuji, Jungeun Kim, Kenichi Kato, Masaki Takata, Hiroki Ishibashi

    Journal of Physics: Conference Series 391 (1) 2012年

    DOI: 10.1088/1742-6596/391/1/012095  

    ISSN:1742-6588

    eISSN:1742-6596

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    Spinel Compound CuV2S4 exhibits incommensurate charge-density wave (CDW) transition at Tt ∼ 90 K accompanied by a structural phase transition. We have performed synchrotron powder diffraction experiments in order to determine the crystal structure for low temperature phase. The CDW phase has an orthorhombic symmetry with the superspace group Imm2(0β0). It was found that the crystal structure is characterized by the significant change of bond lengths between vanadium atoms along a-axis. We suggested that this change is related to the orbital ordering of t2g orbitals, which is the origin of the formation of the CDW. © Published under licence by IOP Publishing Ltd.

  205. Structure of disordered materials studied by high-energy x-ray diffraction technique

    S. Kohara, K. Ohara, L. Temleitner, Y. Ohishi, A. Fujiwara, M. Takata

    Materials Science Forum 706-709 1690-1695 2012年

    DOI: 10.4028/www.scientific.net/MSF.706-709.1690  

    ISSN:0255-5476

    eISSN:1662-9752

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    With the arrival of the third generation of synchrotron sources and/or the introduction of advanced insertion devices (wigglers and undulators), the high energy (E > 50 keV) x-ray diffraction technique has become feasible, leading to new approaches in the quantitative study of the structure of disordered materials than was hither to available. Since we built the SPring-8 bending magnet beamline BL04B2 and two-axis diffractometer for disordered materials in 1999, we have studied on disordered materials from ambient to extreme condition. In this article, the high-energy x-ray diffraction beamline BL04B2 of SPring-8 and recent developments of ancillary equipment (automatic sample changer, conventional high-temperature furnace, aerodynamic levitation furnace) are introduced. Furthermore the structural analysis on the basis of diffraction data with the aid of computer simulations, which we performed in the last 10 years is reviewed. © 2012 Trans Tech Publications, Switzerland.

  206. Processing, mechanical properties, and structure analysis of melt-spun fibers of P(3HB)/UHMW-P(3HB) identical blend

    Taizo Kabe, Takeharu Tsuge, Takaaki Hikima, Masaki Takata, Akio Takemura, Tadahisa Iwata

    ACS Symposium Series 1105 63-75 2012年

    DOI: 10.1021/bk-2012-1105.ch005  

    ISSN:0097-6156

    eISSN:1947-5918

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    High tensile strength melt-spun fibers of poly[(R)-3-hydroxybutyrate] (P(3HB)) with the addition of a small amount of ultra-high-molecular-weight P(3HB) (UHMW-P(3HB)) were processed by cold-drawing and two-step cold-drawing methods. The mechanical properties and highly ordered structure were investigated by tensile testing, and wide-angle and small-angle X-ray diffraction measurements (WAXD and SAXS) using a synchrotron radiation beam at SPring-8. The molecular weight of P(3HB) decreased drastically within a few minutes during melt-spinning. However, in the case of the blended samples, the degree of molecular weight decrease was slightly reduced by the addition of UHMW-P(3HB). The melt-spun blend fibers stretched at a cold-drawing ratio of 14 showed a tensile strength of 530 MPa. When two-step cold-drawing was applied, the tensile strength increased further to 740 MPa. WAXD and SAXD revealed that the addition of a small amount of UHMW-P(3HB) into P(3HB) induces the formation of the β-form (planar zigzag conformation) of molecular chain, increasing the mechanical properties. Based on these results, it seems that the addition of a small amount of UHMW-P(3HB) has a great effect on the thermal stability and processability of melt-spun fibers and increases their final mechanical properties. © 2012 American Chemical Society.

  207. Charge density in materials and energy science

    Jacob Overgaard, Yuri Grin, Masaki Takata, Bo B. Iversen

    Modern Charge-Density Analysis 469-504 2012年1月1日

    DOI: 10.1007/978-90-481-3836-4_13  

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    © Springer Science+Business Media B.V. 2012. During the last decade charge density studies have matured and more and more studies target specific chemical, physical or biological issues rather than method development. Indeed a very wide range of information can be retrieved from analysis of charge densities. Here we review recent applications of charge density analysis in materials science with emphasis on thermoelectric, magnetic and porous materials.

  208. Protein encapsulation within synthetic molecular hosts

    Daishi Fujita, Kosuke Suzuki, Sota Sato, Maho Yagi-Utsumi, Yoshiki Yamaguchi, Nobuhiro Mizuno, Takashi Kumasaka, Masaki Takata, Masanori Noda, Susumu Uchiyama, Koichi Kato, Makoto Fujita

    Nature Communications 3 2012年

    DOI: 10.1038/ncomms2093  

    eISSN:2041-1723

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    Protein encapsulation has long attracted many chemists and biologists because of its potential to control the structure and functions of proteins, but has been a daunting challenge because of their incommensurably larger size compared with common synthetic hosts. Here we report the encapsulation of a small protein, ubiquitin, within giant coordination cages. The protein was attached to one bidentate ligand and, upon addition of Pd(II) ions (M) and additional ligands (L), M 12 L 24 coordination nanocages self-assembled around the protein. Because of the well-defined host framework, the protein-encapsulated structure could be analysed by NMR spectroscopy, ultracentrifugation and X-ray crystallography. © 2012 Macmillan Publishers Limited. All rights reserved.

  209. Mechanical properties, structure analysis and enzymatic degradation of uniaxially cold-drawn films of poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate]

    Jiaqi Zhang, Kenichi Kasuya, Takaaki Hikima, Masaki Takata, Akio Takemura, Tadahisa Iwata

    Polymer Degradation and Stability 96 (12) 2130-2138 2011年12月

    DOI: 10.1016/j.polymdegradstab.2011.09.011  

    ISSN:0141-3910

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    Poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate] (P(3HB-co-4HB)) films were prepared by uniaxial cold-drawing from an amorphous preform at a temperature below, but close to the glass transition temperature. Molecular and highly-ordered structures and physical properties of cold-drawn films were investigated by tensile testing, wide-angle X-ray diffraction and small-angle X-ray scattering. Enzymatic degradation of P(3HB-co-4HB) films was performed using an extracellular polyhydroxybutyrate depolymerase purified from Ralstonia pickettii T1. Tensile strength, elongation to break and Young's modulus of P(3HB-co-4HB) with cold-drawn ratio 1200% reached 290 MPa, 58% and 2.8 GPa, respectively. X-ray fibre diagrams of cold-drawn P(3HB-co-4HB) films showed a strong reflection on the equatorial line, indicating a planar zigzag conformation (β-form) together with 21 helix conformation (α-form). The β-form seems to contribute to the high tensile strength, and a new mechanism of generation of the β-form is proposed. The enzymatic degradation rate increased with increasing draw ratio, and increased greatly with increasing 4HB content. © 2011 Elsevier Ltd. All rights reserved.

  210. Analysis of the photomagnetic properties of cyano-bridged heterobimetallic complexes by X-ray diffraction

    Helle Svendsen, Mads Ry Vogel Jørgensen, Jacob Overgaard, Yu Sheng Chen, Guillaume Chastanet, Jean François Létard, Kenichi Kato, Masaki Takata, Bo B. Iversen

    Inorganic Chemistry 50 (21) 10974-10984 2011年11月7日

    DOI: 10.1021/ic2015258  

    ISSN:0020-1669

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    Single crystal synchrotron X-ray diffraction measurements have been carried out on [Nd(DMF)4(H2O)3(μ-CN)Fe(CN) 5]•H2O (DMF = dimethyl-formamide), 1; [Y(DMF) 4(H2O)3(μ-CN)Fe(CN)5]•H 2O, 2; [Ce(DMF)4(H2O)3(μ-CN) Fe(CN)5]•H2O, 3; [Sm(DMF)4(H 2O)3(μ-CN)Fe(CN)5]•H2O, 4; [Tb(DMF)4(H2O)3(μ-CN)Fe(CN) 5]•H2O, 5; [Yb(DMF)4(H2O) 3(μ-CN)Fe(CN)5]•H2O, 6; and [Nd(DMF)4(H2O)3(μ-CN)Co(CN) 5]•H2O, 7, at 15(2) K with and without UV illumination of the crystals. Significant changes in unit cell parameters are observed for all of the iron-containing complexes, while compound 7 shows no response to UV illumination. These results are consistent with previous results and are furthermore reproduced by powder synchrotron X-ray diffraction for compounds 1 and 7. Photoexcited crystal structures have been determined for 1-6 from refinements of two-conformer models, and excited state occupancies in the range 80-94% are found. Significant bond length changes are observed for the Fe-ligand bonds (up to 0.06 Å), the cyano bonds (up to 0.02 Å), and the lanthanide-ligand bonds (up to 0.1 Å). On the contrary, powder X-ray diffraction on the simple compound K3Fe(CN)6, 8, upon UV illumination does not show any structural changes, suggesting that the photomagnetic effect requires the presence of both the transition metal and the lanthanide ion. Photomagnetic measurements show an increase in magnetization of the excited state of 1 of up to 3%, which is much diminished compared with previously published values of 45%. Furthermore, they show that the isostructural complex [La(DMF)4(H2O)3(μ-CN) Fe(CN)5]•H2O, 9, exhibits identical magnetic responses in the UV-induced excited crystal structure. © 2011 American Chemical Society.

  211. Gas detection by structural variations of fluorescent guest molecules in a flexible porous coordination polymer

    Nobuhiro Yanai, Koji Kitayama, Yuh Hijikata, Hiroshi Sato, Ryotaro Matsuda, Yoshiki Kubota, Masaki Takata, Motohiro Mizuno, Takashi Uemura, Susumu Kitagawa

    Nature Materials 10 (10) 787-793 2011年10月

    DOI: 10.1038/nmat3104  

    ISSN:1476-1122

    eISSN:1476-4660

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    The development of a new methodology for visualizing and detecting gases is imperative for various applications. Here, we report a novel strategy in which gas molecules are detected by signals from a reporter guest that can read out a host structural transformation. A composite between a flexible porous coordination polymer and fluorescent reporter distyrylbenzene (DSB) selectively adsorbed CO2 over other atmospheric gases. This adsorption induced a host transformation, which was accompanied by conformational variations of the included DSB. This read-out process resulted in a critical change in DSB fluorescence at a specific threshold pressure. The composite shows different fluorescence responses to CO2 and acetylene, compounds that have similar physicochemical properties. Our system showed, for the first time, that fluorescent molecules can detect gases without any chemical interaction or energy transfer. The host-guest coupled transformations play a pivotal role in converting the gas adsorption events into detectable output signals. © 2011 Macmillan Publishers Limited. All rights reserved.

  212. Electronic structure and localized lanthanide character of LnT <inf>2</inf>Al<inf>10</inf> (T=Ru, Os)

    H. Tanida, D. Tanaka, M. Sera, S. Tanimoto, T. Nishioka, M. Matsumura, M. Ogawa, C. Moriyoshi, Y. Kuroiwa, J. E. Kim, N. Tsuji, M. Takata

    Physical Review B - Condensed Matter and Materials Physics 84 (11) 2011年9月21日

    DOI: 10.1103/PhysRevB.84.115128  

    ISSN:1098-0121

    eISSN:1550-235X

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    The high-energy synchrotron x-ray powder diffraction experiments of LaRu2Al10 were carried out to clarify the charge-density distribution, which is derived by the maximum entropy method/Rietveld technique. The results indicate that the charge density between Ru and surrounding Al atoms is large, but that between La and surrounding Al atoms is small. We propose that the Ru-Al10 polyhedron is the fundamental component of the crystal and the two-dimensional layer is constructed by these polyhedra in the ac plane and is stacked along the b axis by way of the Al5 atom. The Ln ion is located inside the crevice formed by the surrounding Ru-Al10 polyhedra and behaves as a nearly free ion. We studied the thermal and magnetic properties of NdT2Al10 (T=Ru, Os), which exhibits the antiferromagnetic order at TN=2.4 and 2.2 K for T=Ru and Os, respectively. We observed a small lattice distortion below TN, which indicates the small coupling between the orbital moment of the Nd ion and the lattice. The results of the magnetic susceptibility indicate the small crystalline electric field effect. These results mean that the Nd ion behaves as a nearly free ion, which is supported by the results of the charge-density distribution of LaRu2Al10. © 2011 American Physical Society.

  213. Synchrotron radiation study on time-resolved tetragonal lattice strain of BaTiO<inf>3</inf> under electric field

    Chikako Moriyoshi, Shozo Hiramoto, Hisanori Ohkubo, Yoshihiro Kuroiwa, Hitoshi Osawa, Kunihisa Sugimoto, Shigeruw Sugimoto, Masaki Takata, Yuuki Kitanaka, Yuji Noguchi, Masaru Miyayama

    Japanese Journal of Applied Physics 50 (9 PART 3) 2011年9月

    DOI: 10.1143/JJAP.50.09NE05  

    ISSN:0021-4922

    eISSN:1347-4065

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    The dynamic response of an intrinsic lattice strain in a tetragonal BaTiO3 single crystal to an electric field is investigated. Time-resolved diffraction measurement using high-energy synchrotron radiation enables us to detect the time dependence of the small change in the tetragonality of BaTiO3 during polarization reversal and piezoelectric vibration after a step like electric field antiparallel to the spontaneous polarization is applied to the sample. © 2011 The Japan Society of Applied Physics.

  214. Electric-field-responsive handle for large-area orientation of discotic liquid-crystalline molecules in millimeter-thick films

    Daigo Miyajima, Fumito Araoka, Hideo Takezoe, Jungeun Kim, Kenichi Kato, Masaki Takata, Takuzo Aida

    Angewandte Chemie - International Edition 50 (34) 7865-7869 2011年8月16日

    DOI: 10.1002/anie.201102472  

    ISSN:1433-7851

    eISSN:1521-3773

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    Current events: An electric-field-responsive handle (see picture) was developed that enables large-area and millimeter-thick unidirectional orientation of columnarly assembled π-conjugated liquid-crystalline molecules. The handles in the columns are hydrogen-bonded and align along the direction of an applied electric field. © 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  215. Magnetically driven ferroelectric atomic displacements in orthorhombic YMnO<inf>3</inf>

    D. Okuyama, S. Ishiwata, Y. Takahashi, K. Yamauchi, S. Picozzi, K. Sugimoto, H. Sakai, M. Takata, R. Shimano, Y. Taguchi, T. Arima, Y. Tokura

    Physical Review B - Condensed Matter and Materials Physics 84 (5) 2011年8月11日

    DOI: 10.1103/PhysRevB.84.054440  

    ISSN:1098-0121

    eISSN:1550-235X

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    Magnetically driven ferroelectric atomic displacements of the order of 10-3 Å have been observed in orthorhombic (perovskite like) YMnO3 by a single-crystal synchrotron x-ray diffraction. The refined polar structure shows the characteristic bond alternation driven by the exchange striction in staggered Mn-O-Mn arrays with ↑↑↓↓ type ordering, giving rise to a spontaneous polarization along the a axis. First-principles calculations based on the Berry phase method as well as on the experimentally refined crystal structure can reproduce the observed polarization value. © 2011 American Physical Society.

  216. The role of the four stereoisomers of the heme Fe-O cyclic dimer in the crystalline phase behavior of synthetic hemozoin: Relevance to native hemozoin crystallization

    Tine Straasø, Sergey Kapishnikov, Kenichi Kato, Masaki Takata, Jens Als-Nielsen, Leslie Leiserowitz

    Crystal Growth and Design 11 (8) 3342-3350 2011年8月3日

    DOI: 10.1021/cg200410b  

    ISSN:1528-7483

    eISSN:1528-7505

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    Hemozoin is a crystalline byproduct formed upon host hemoglobin digestion in malaria-infected blood cells, crucial for parasitic survival. On the basis of published spectroscopic and X-ray powder diffraction (XRPD) data, hemozoin is believed to be very similar to the synthetic compound β-hematin, which consists of cyclic centrosymmetric dimers of ferriprotoporphyrin IX [Fe(3+) PPIX] molecules coordinated via Fe-O bonds. The enantio-facial symmetry of Fe(3+) PPIX implies, however, that four different Fe-O cyclic stereoisomers, two centrosymmetric and two chiral, of opposite handedness, should be formed in the crystallizing solution of β-hematin. A low-temperature XRPD study of β-hematin, i.e. synthetic hemozoin, revealed the presence, not only of the published phase (Pagola, S.; Stephens, P. W.; Bohle, D. S.; Kosar, A. D.; Madsen, S. K.Nature 2000, 404, 307) but also of a minor phase. We propose, based on Rietveld refinement and DFT+vdW computations (companion manuscript, DOI: 10.1021/cg200409d), that the minor phase consists mainly of the second centrosymmetric isomeric type in a crystal structure similar to that of the major phase. The enantiomeric chiral isomers may, on symmetry grounds, be enantioselectively occluded into the growing crystals, introducing disorder. The chiral dimers, on being first adsorbed on the crystal faces, would act as tailor-made additives, retarding crystal growth, which also explains the crystalline micrometer size. The existence of two phases in β-hematin may be crucial for a fuller understanding and more complete determination of the crystal structure of hemozoin, of which only one phase has crystallized according to published data. © 2011 American Chemical Society.

  217. Cellulose hydrolysis by a new porous coordination polymer decorated with sulfonic acid functional groups

    George Akiyama, Ryotaro Matsuda, Hiroshi Sato, Masaki Takata, Susumu Kitagawa

    Advanced Materials 23 (29) 3294-3297 2011年8月2日

    DOI: 10.1002/adma.201101356  

    ISSN:0935-9648

    eISSN:1521-4095

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    A MIL-101-based porous coordination polymer (PCP) containing sulfonic acid groups is synthesized. The sulfonic groups are exposed on the pore surface and act as strong Brønsted acid sites. This solid acid PCP catalytically hydrolyzes cellulose into mono- and disaccharides and shows high durability in the catalytic reaction. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  218. Nanosize-induced hydrogen storage and capacity control in a non-hydride-forming element: Rhodium

    Hirokazu Kobayashi, Hitoshi Morita, Miho Yamauchi, Ryuichi Ikeda, Hiroshi Kitagawa, Yoshiki Kubota, Kenichi Kato, Masaki Takata

    Journal of the American Chemical Society 133 (29) 11034-11037 2011年7月27日

    DOI: 10.1021/ja2027772  

    ISSN:0002-7863

    eISSN:1520-5126

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    We report the first example of nanosize-induced hydrogen storage in a metal that does not absorb hydrogen in its bulk form. Rhodium particles with diameters of <10 nm were found to exhibit hydrogen-storage capability, while bulk Rh does not absorb hydrogen. Hydrogen storage was confirmed by in situ powder X-ray diffraction, solid-state 2H NMR, and hydrogen pressure - composition isotherm measurements. The hydrogen absorption capacity could be tuned by controlling the particle size. © 2011 American Chemical Society.

  219. Super flexibility of a 2D Cu-based porous coordination framework on gas adsorption in comparison with a 3D framework of identical composition: Framework dimensionality-dependent gas adsorptivities

    Atsushi Kondo, Hiroshi Kajiro, Hiroshi Noguchi, Lucia Carlucci, Davide M. Proserpio, Gianfranco Ciani, Kenichi Kato, Masaki Takata, Hiroko Seki, Masami Sakamoto, Yoshiyuki Hattori, Fujio Okino, Kazuyuki Maeda, Tomonori Ohba, Katsumi Kaneko, Hirofumi Kanoh

    Journal of the American Chemical Society 133 (27) 10512-10522 2011年7月13日

    DOI: 10.1021/ja201170c  

    ISSN:0002-7863

    eISSN:1520-5126

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    Selective synthetic routes to coordination polymers [Cu(bpy) 2(OTf)2]n (bpy = 4,4′-bipyridine, OTf = trifluoromethanesulfonate) with 2- and 3-dimensionalities of the frameworks were established by properly choosing each different solvent-solution system. They show a quite similar local coordination environment around the Cu(II) centers, but these assemble in a different way leading to the 2D and 3D building-up structures. Although the two kinds of porous coordination polymers (PCPs) both have flexible frameworks, the 2D shows more marked flexibility than the 3D, giving rise to different flexibility-associated gas adsorption behaviors. All adsorption isotherms for N2, CO2, and Ar on the 3D PCP are of type I, whereas the 2D PCP has stepwise gas adsorption isotherms, also for CH4 and water, in addition to these gases. The 3D structure, having hydrophilic and hydrophobic pores, shows the size-selective and quadrupole-surface electrical field interaction dependent adsorption. Remarkably, the 2D structure can accommodate greater amounts of gas molecules than that corresponding to the inherent crystallographic void volume through framework structural changes. In alcohol adsorption isotherms, however, the 2D PCP changes its framework structure through the guest accommodation, leading to no stepwise adsorption isotherms. The structural diversity of the 2D PCP stems from the breathing phenomenon and expansion/shrinkage modulation. © 2011 American Chemical Society.

  220. Giant negative thermal expansion in the iron perovskite SrCu <inf>3</inf>Fe<inf>4</inf>O<inf>12</inf>

    Ikuya Yamada, Kazuki Tsuchida, Kenya Ohgushi, Naoaki Hayashi, Jungeun Kim, Naruki Tsuji, Ryoji Takahashi, Masafumi Matsushita, Norimasa Nishiyama, Toru Inoue, Tetsuo Irifune, Kenichi Kato, Masaki Takata, Mikio Takano

    Angewandte Chemie - International Edition 50 (29) 6579-6582 2011年7月11日

    DOI: 10.1002/anie.201102228  

    ISSN:1433-7851

    eISSN:1521-3773

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    Big and cold: Strong internal compression of the Sr ion in the novel perovskite SrCu3Fe4O12 (see structure) leads to giant negative thermal expansion (NTE) between 170 and 270 K. Mössbauer spectroscopy shows charge disproportionation of FeIV to Fe III and FeV below 200 K. Thus, the isoelectric substitution of the A-site cation can induce a drastic change of the structural and electronic properties in ACu3Fe4O12 perovskites. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  221. Phase-change materials: Vibrational softening upon crystallization and its impact on thermal properties

    Toshiyuki Matsunaga, Noboru Yamada, Rie Kojima, Shinichi Shamoto, Masugu Sato, Hajime Tanida, Tomoya Uruga, Shinji Kohara, Masaki Takata, Peter Zalden, Gunnar Bruns, Ilya Sergueev, Hans Christian Wille, Raphaël Pierre Hermann, Matthias Wuttig

    Advanced Functional Materials 21 (12) 2232-2239 2011年6月21日

    DOI: 10.1002/adfm.201002274  

    ISSN:1616-301X

    eISSN:1616-3028

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    Crystallization of an amorphous solid is usually accompanied by a significant change of transport properties, such as an increase in thermal and electrical conductivity. This fact underlines the importance of crystalline order for the transport of charge and heat. Phase-change materials, however, reveal a remarkably low thermal conductivity in the crystalline state. The small change in this conductivity upon crystallization points to unique lattice properties. The present investigation reveals that the thermal properties of the amorphous and crystalline state of phase-change materials show remarkable differences such as higher thermal displacements and a more pronounced anharmonic behavior in the crystalline phase. These findings are related to the change of bonding upon crystallization, which leads to an increase of the sound velocity and a softening of the optical phonon modes at the same time. Crystallization of amorphous solids is usually accompanied by significant changes of transport properties, such as an increase in thermal conductivity. Phase-change materials, however, reveal a remarkably low thermal conductivity in the crystalline state. This phenomenon is caused by the change of bonding upon crystallization which leads to an increase of the sound velocity and a softening of the optical modes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  222. Soft secondary building unit: Dynamic bond rearrangement on multinuclear core of porous coordination polymers in gas media

    Joobeom Seo, Charlotte Bonneau, Ryotaro Matsuda, Masaki Takata, Susumu Kitagawa

    Journal of the American Chemical Society 133 (23) 9005-9013 2011年6月15日

    DOI: 10.1021/ja201484s  

    ISSN:0002-7863

    eISSN:1520-5126

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    A new synthetic approach to prepare flexible porous coordination polymers (PCPs) by the use of soft secondary building units (SBUs) which can undergo multiple reversible metal-ligand bonds breaking is reported. We have prepared a zinc paddle-wheel-based two-fold interpenetrated PCP, {[Zn2(tp) 2(L2)]•2.5DMF•0.5water}n (2a, H 2tp = terephthanlic acid; L2 = 2,3-difluoro-1,4-bis(4- pyridyl)benzene), showing dynamic structural transformations upon the removal and rebinding of guest molecules. The X-ray structures at different degrees of desolvation indicate the highly flexible nature of the framework. The framework deformations involve slippage of the layers and movement of the two interpenetrated frameworks with respect to each other. Interestingly, the coordination geometry of a zinc paddle-wheel unit (one of the popular SBUs) is considerably changed by bond breaking between zinc and oxygen atoms during the drying process. Two zinc atoms in the dried form 2d reside in a distorted tetrahedral geometry. Compound 2d has no void volume and favors the uptake of O2 over Ar and N2 at 77 K. The O2 and Ar adsorption isotherms of 2d show gate-opening-type adsorption behaviors corroborating the structure determination. The CO2 adsorption isotherm at 195 K exhibits multiple steps originating from the flexibility of the framework. The structural transformations of the zinc clusters in the framework upon sorption of guest molecules are also characterized by Raman spectroscopy in which the characteristic bands corresponding to νsym(COO-) vibration were used. © 2011 American Chemical Society.

  223. Electron- or hole-transporting nature selected by side-chain-directed π-stacking geometry: Liquid crystalline fused metalloporphyrin dimers

    Tsuneaki Sakurai, Kentaro Tashiro, Yoshihito Honsho, Akinori Saeki, Shu Seki, Atsuhiro Osuka, Atsuya Muranaka, Masanobu Uchiyama, Jungeun Kim, Sunyeo Ha, Kenichi Kato, Masaki Takata, Takuzo Aida

    Journal of the American Chemical Society 133 (17) 6537-6540 2011年5月4日

    DOI: 10.1021/ja201272t  

    ISSN:0002-7863

    eISSN:1520-5126

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    Novel liquid crystalline (LC) semiconductors were prepared from the copper complex of a fused porphyrin dimer as the electroactive core by attaching to its periphery dodecyl and semifluoroalkyl side chains site-specifically (P=P hetero) and semifluoroalkyl side chains alone (P=Phomo). The former and latter formed rectangular columnar and orthorhombic LC mesophases, respectively, where the stacking geometries of the π-conjugated core are quite different from one another. Although the π-electronic properties of the core units in P=Phetero and P=Phomo in solution are substantially identical to one another, transient photocurrent profiles of their LC states under time-of-flight conditions clearly showed that P=Phetero behaves as an n-type semiconductor, whereas P=P homo, in contrast, behaves as a p-type semiconductor. © 2011 American Chemical Society.

  224. Multipurpose soft-material SAXS/WAXS/GISAXS beamline at SPring-8

    Hiroyasu Masunaga, Hiroki Ogawa, Takumi Takano, Sono Sasaki, Shunji Goto, Takashi Tanaka, Takamitsu Seike, Sunao Takahashi, Kunikazu Takeshita, Nobuteru Nariyama, Haruhiko Ohashi, Toru Ohata, Yukito Furukawa, Tomohiro Matsushita, Yasuhide Ishizawa, Naoto Yagi, Masaki Takata, Hideo Kitamura, Kazuo Sakurai, Kohji Tashiro, Atsushi Takahara, Yoshiyuki Amamiya, Kazuyuki Horie, Mikihito Takenaka, Toshiji Kanaya, Hiroshi Jinnai, Hiroshi Okuda, Isamu Akiba, Isao Takahashi, Katsuhiro Yamamoto, Masamichi Hikosaka, Shinichi Sakurai, Yuya Shinohara, Akihiko Okada, Yasunori Sugihara

    Polymer Journal 43 (5) 471-477 2011年5月

    DOI: 10.1038/pj.2011.18  

    ISSN:0032-3896

    eISSN:1349-0540

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    Scientific and engineering research on soft materials requires precise structural analysis to understand their hierarchical and fluctuating nature. A new beamline, the BL03XU frontier soft-material beamline, that is dedicated to scattering experiments on soft materials was recently installed at the third-generation synchrotron facility, SPring-8, in Japan. The BL03XU uses an in-vacuum undulator, and the photon flux of the obtained X-ray can reach 10 13 photons sec-1, with an energy resolution of ΔE/E ≈ 2 × 10-4 at 12.4 keV. The BL03XU has two experimental hutches: a front one that is used for grazing-incidence scattering experiments and a second one for transmitting scattering experiments, which enables simultaneous small- and wide-angle X-ray scattering. The present paper introduces details about the instrument and some of the first scattering data measured at BL03XU, which reveals its cutting-edge design and high level of performance. © The Society of Polymer Science, Japan (SPSJ) All rights reserved.

  225. An electrostatic potential study of asymmetric ionic conductivity in Li<inf>2</inf>B<inf>4</inf>O<inf>7</inf> crystals

    Su Jae Kim, Won Kyung Kim, Yong Chan Cho, S. Park, I. K. Jeong, Y. S. Yang, Yoshihiro Kuroiwa, Chikako Moriyoshi, Hiroshi Tanaka, Masaki Takata, Se Young Jeong

    Current Applied Physics 11 (3) 649-652 2011年5月

    DOI: 10.1016/j.cap.2010.10.019  

    ISSN:1567-1739

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    This study investigated the bonding nature and electrostatic potential of asymmetric Li ionic mobility in Li2B4O7 crystals using the maximum entropy method (MEM) combined with Rietveld refinement and Ewalds technique. Compared with the interaction between oxygen and boron, Li+ ions exhibited weak interactions with both oxygen and boron. Furthermore, electrostatic-potential-distribution analysis showed that Li+ ions had a much weaker interaction with the matrix along the c-axis channel, suggesting that higher ionic conductivity occurred along the c-axis than along the a- and b-axes. © 2010 Elsevier B.V. All rights reserved.

  226. Competition between vanadium tetramerization and trimerization in Ba <inf>1-x</inf>Sr<inf>x</inf>V<inf>13</inf>O<inf>18</inf>

    M. Ikeda, T. Okuda, K. Kato, M. Takata, T. Katsufuji

    Physical Review B - Condensed Matter and Materials Physics 83 (13) 2011年4月

    DOI: 10.1103/PhysRevB.83.134417  

    ISSN:1098-0121

    eISSN:1550-235X

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    We studied the transport, magnetic, and structural properties of Ba 1-xSrxV13O18, in which V and O ions form a sodium-chloride lattice with periodically missing sites. We found that the high-temperature insulating phase is characterized by spin-singlet V tetramers, whereas the low-temperature conducting phase is characterized by V trimers, and these two phases are competing in this series of compounds. Various properties substantially change at the phase transition between the two, indicating a drastic reconstruction of the electronic structure. © 2011 American Physical society.

  227. Highly selective ammonia synthesis from nitrate with photocatalytically generated hydrogen on CuPd/TiO<inf>2</inf>

    Miho Yamauchi, Ryu Abe, Tatsuya Tsukuda, Kenichi Kato, Masaki Takata

    Journal of the American Chemical Society 133 (5) 1150-1152 2011年2月9日

    DOI: 10.1021/ja106285p  

    ISSN:0002-7863

    eISSN:1520-5126

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    Body-centered-cubic type CuPd nanoalloys were synthesized by a chemical reduction method. Photocatalytic hydrogen evolution and nitrate reduction were simultaneously examined over CuPd nanoalloys deposited on TiO2 (CuPd/TiO2). The efficiency of hydrogen evolution over CuPd/TiO 2 was better than that over Pd/TiO2. As for nitrate reduction, ammonia was selectively (78%) produced with hydrogen generated photocatalytically over CuPd/TiO2. The continuous generation of nascent hydrogen atoms on the surface of the CuPd nanoalloy, where Cu and Pd are homogeneously mixed, led to the high selectivity for ammonia. © 2011 American Chemical Society.

  228. From local structure to nanosecond recrystallization dynamics in AgInSbTe phase-change materials

    Toshiyuki Matsunaga, Jaakko Akola, Shinji Kohara, Tetsuo Honma, Keisuke Kobayashi, Eiji Ikenaga, Robert O. Jones, Noboru Yamada, Masaki Takata, Rie Kojima

    Nature Materials 10 (2) 129-134 2011年2月

    DOI: 10.1038/nmat2931  

    ISSN:1476-1122

    eISSN:1476-4660

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    Phase-change optical memories are based on the astonishingly rapid nanosecond-scale crystallization of nanosized amorphous marksgin a polycrystalline layer. Models of crystallization exist for the commercially used phase-change alloy Ge 2 Sb 2 Te 5 (GST), but not for the equally important class of Sbĝ€"Te-based alloys. We have combined X-ray diffraction, extended X-ray absorption fine structure and hard X-ray photoelectron spectroscopy experiments with density functional simulations to determine the crystalline and amorphous structures of Ag3.5 In 3.8 Sb 75.0 Te17.7 (AIST) and how they differ from GST. The structure of amorphous (a-) AIST shows a range of atomic ring sizes, whereas a-GST shows mainly small rings and cavities. The local environment of Sb in both forms of AIST is a distorted 3+3 octahedron. These structures suggest a bond-interchange model, where a sequence of small displacements of Sb atoms accompanied by interchanges of short and long bonds is the origin of the rapid crystallization of a-AIST. It differs profoundly from crystallization in a-GST. © 2011 Macmillan Publishers Limited. All rights reserved.

  229. Extended d-electron state of Fe(CN)<inf>6</inf> unit in Prussian blue analogue

    Jungeun Kim, Hiroshi Tanaka, Kenichi Kato, Masaki Takata, Yutaka Moritomo

    Applied Physics Express 4 (2) 2011年2月

    DOI: 10.1143/APEX.4.025801  

    ISSN:1882-0778

    eISSN:1882-0786

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    The Prussian blue analogue, AxM[Fe(CN)6]y zH2O (A and M are an alkali metal and a transition metal, respectively), is one of the candidates for a positive electrode material of a lithium-ion secondary battery. For further development of the electrode material, deeper understanding of the redox states of the constituents, i.e., M and the Fe(CN)6 unit, is indispensable. Here, we investigated the electronic state of the redox constituents of K0.34Co[Fe(CN) 6]0.753.6H2O by means of the electrostatic potential method combined with the maximum entropy method combined with the Rietveld analysis (MEM/Rietveld). The electrostatic potential U(r) revealed that both the reduced and oxidixed states of Fe extend to the surrounding CN groups, which may cause the robustness of the cyano-bridged transition metal network. © 2011 The Japan Society of Applied Physics.

  230. Giant Negative Thermal Expansion in a Novel Iron Perovskite SrCu3Fe4O12 査読有り

    123 6709-6712 2011年

    DOI: 10.1002/anie.201102228  

  231. Neutron diffraction study on magnetic structure in layered manganite La<inf>2-2x</inf>Sr<inf>1+2x</inf>Mn<inf>2</inf>O<inf>7</inf> (x=0.307)

    Hirosuke Sonomura, Tomoyuki Terai, Tomoyuki Kakeshita, Toyotaka Osakabe, Kazuhisa Kakurai, Yoshihiro Kuroiwa, Chikako Moriyoshi, Toshinori Okubo, Kenichi Kato, Jungeun Kim, Masaki Takata

    Solid State Phenomena 172-174 1301-1306 2011年

    DOI: 10.4028/www.scientific.net/SSP.172-174.1301  

    ISSN:1012-0394

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    Magnetic structure in a layered perovskite manganite, La 2-2xSr1+2xMn2O7 (x = 0.307) has been investigated by neutron diffraction measurements. We found that the ground state (at 4 K) has a ferromagnetic structure with magnetic moment of Mn ions being aligned in a direction inclined by 10 degree from the c-axis. The magnetic structure changes to a canted antiferromagnetic one (CAFM-I) at about 20 K and then to another canted antiferromagnetic one (CAFM-II) at about 80 K. Here the magnetic moment lies in the ab-plane in CAFM-II but not in CAFM-I. The magnetic structure then changes to an antiferromagnetic one with magnetic moment lies in the ab-plane at about 90 K, and then to a paramagnetic one at about 100 K. © (2011) Trans Tech Publications.

  232. X-ray photon correlation spectroscopy of silica particles grafted with polymer brush in polystyrene matrix

    Taiki Hoshino, Moriya Kikuchi, Daiki Murakami, Koji Mitamura, Yoshiko Harada, Kiminori Ito, Yoshihito Tanaka, Sono Sasaki, Masaki Takata, Atsushi Takahara

    Journal of Physics: Conference Series 272 (1) 2011年

    DOI: 10.1088/1742-6596/272/1/012020  

    ISSN:1742-6588

    eISSN:1742-6596

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    X-ray photon correlation spectroscopy system was setup at SPring-8, BL19LXU, and the partial coherence scattering data from the silica particles grafted with polymer brush in polystyrene matrix were measured. Firstly, the static speckle patterns were checked. Below the glass transition temperature of polystyrene (Tg), speckles were clearly observed, on the other hand, above Tg, the scattering patterns became smooth and speckles were hardly observed. These variances of the speckle patterns result from the particle motion. Secondly, from the time variance of the speckle data, time autocorrelation functions g2(q,t) are calculated. While the flat behaviour of g2(q,t) without relaxation were observed below T g, the relaxation behavior with relaxation time∼10 0-101 were observed above Tg © Published under licence by IOP Publishing Ltd.

  233. Differences of crystal structure and dynamics between a soft porous nanocrystal and a bulk crystal

    Yuh Hijikata, Satoshi Horike, Daisuke Tanaka, Juergen Groll, Motohiro Mizuno, Jungeun Kim, Masaki Takata, Susumu Kitagawa

    Chemical Communications 47 (27) 7632-7634 2011年

    DOI: 10.1039/c1cc10983a  

    ISSN:1359-7345

    eISSN:1364-548X

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    We have demonstrated downsizing effects of the soft porous crystal, [Zn(isophthalate)(4,4′-bipyridyl)]n (CID-1), on the adsorption behavior between CID-1 and CID-1 nanocrystal (NCID-1). The difference results from the packing crystal structures and the dynamics of the frameworks. © 2011 The Royal Society of Chemistry.

  234. Upgrade status of hard X-ray 100-nm probe beamlines BL37XU and BL39XU at SPring-8

    Takahisa Koyama, Hirokatsu Yumoto, Yasuko Terada, Motohiro Suzuki, Naomi Kawamura, Masaichiro Mizumaki, Nobuteru Nariyama, Tomohiro Matsushita, Yasuhide Ishizawa, Yukito Furukawa, Toru Ohata, Hiroshi Yamazaki, Tomoyuki Takeuchi, Yasunori Senba, Yasuhisa Matsuzaki, Masayuki Tanaka, Yasuhiro Shimizu, Hikaru Kishimoto, Takanori Miura, Hiroaki Kimura, Kunikazu Takeshita, Haruhiko Ohashi, Masaki Yamamoto, Shunji Goto, Masaki Takata, Tetsuya Ishikawa

    Proceedings of SPIE - The International Society for Optical Engineering 8139 2011年

    DOI: 10.1117/12.893459  

    ISSN:0277-786X

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    BL37XU (trace element analysis beamline) and BL39XU (magnetic materials beamline) at SPring-8 have been upgraded to provide nano-probe analysis. We designed and installed Kirkpatrick-Baez (KB) mirrors and corresponding manipulators, which have an X-ray focusing beam as small as 100 nm. To realize a high-flux 100-nm focusing beam, a high-demagnification optical design was used, and new experimental hutches were constructed that are located about 80 m from the light source. By taking advantage of extended beamline, focusing photon flux density of over 1 × 109 (photons/sec/100×100nm 2) is possible with a working distance of 100 mm at X-ray energy of around 10 keV. The current status of these beamlines is reported. © 2011 SPIE.

  235. The photo-induced commensurate modulated structure in site-selective spin crossover complex trans-[Fe(abpt)<inf>2</inf>(NCS)<inf>2</inf>]

    Che Hsiu Shih, Chou Fu Sheu, Kenichi Kato, Kunihisa Sugimoto, Jungeun Kim, Yu Wang, Masaki Takata

    Dalton Transactions 39 (41) 9794-9800 2010年11月7日

    DOI: 10.1039/c0dt00470g  

    ISSN:1477-9226

    eISSN:1477-9234

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    The photo-induced superstructure of polymorph C of trans-[Fe(abpt) 2(NCS)2] (abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4- triazole) is discovered as a commensurate modulated structure by single-crystal X-ray diffraction under irradiation. The crystal structure at 25 K before the photo-irradiation composed of two crystallographically independent iron molecules, one of which exhibits high spin (HS) state and the other at low spin (LS) state. Under green laser light (λ = 532 nm) irradiation, the LS molecule (Fe1) is found to be excited to a metastable HS state and gives rise to a commensurate tripled superstructure along the c axis. In addition, it is confirmed that this modulation persists until the HS → LS relaxation temperature beyond 52 K. Our structural findings suggest that the structural modulation and the site-selective LS → HS excitation are highly correlated. © 2010 The Royal Society of Chemistry.

  236. Large-area three-dimensional molecular ordering of a polymer brush by one-step processing

    Nobuhiko Hosono, Takashi Kajitani, Takanori Fukushima, Kazuki Ito, Sono Sasaki, Masaki Takata, Takuzo Aida

    Science 330 (6005) 808-811 2010年11月5日

    DOI: 10.1126/science.1195302  

    ISSN:0036-8075

    eISSN:1095-9203

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    Rational molecular design and processing, enabling large-area molecular ordering, are important for creating high-performance organic materials and devices. We show that, upon one-step hot-pressing with uniaxially stretched Teflon sheets, a polymer brush carrying azobenzene-containing mesogenic side chains self-assembles into a freestanding film, where the polymer backbone aligns homeotropically to the film plane and the side chains align horizontally. Such an ordered structure forms through translation of a one-dimensional molecular order of the Teflon sheet and propagates from the interface macroscopically on both sides of the film. The resultant wide-area bimorph configuration allows the polymer film to bend rapidly and reversibly when the azobenzene units are photoisomerized. The combination of polymer brushes with hot-pressing and Teflon sheets provides many possibilities in designing functional soft materials.

  237. Lead silicate glasses: Binary network-former glasses with large amounts of free volume

    S. Kohara, H. Ohno, M. Takata, T. Usuki, H. Morita, K. Suzuya, J. Akola, L. Pusztai

    Physical Review B - Condensed Matter and Materials Physics 82 (13) 2010年10月29日

    DOI: 10.1103/PhysRevB.82.134209  

    ISSN:1098-0121

    eISSN:1550-235X

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    It is well known that PbO-SiO2 exhibits a wide glass formation composition range, up to 90 mol% PbO. Earlier studies suggest that the existence of PbO3 or PbO4 structural units, which act like network formers, may be the reason for the wide glass formation range but the structure beyond short-range order is still unclear. Here we found that the network formation in the glass is governed by the interplay of SiO4 tetrahedra and PbOx polyhedra (x=3-5, x=4 is major) as a network former while the distribution of other (non-network) units is inhomogeneous. The inhomogeneous distribution of PbOx polyhedra in the 34 mol% PbO glass and that of SiO4 tetrahedra in the 65 mol% PbO glass yield a prepeak at Q<1.5 Å⊃-1, a sign of a characteristic length of the inhomogeneity in the diffraction patterns. Furthermore, PbO-SiO2 glasses contain extraordinarily large amounts of free volume (voids), which cannot be found in conventional binary silicate glasses (network former-network modifier) but only in network-former glasses such as SiO2 glass and in its mixtures with another network former such as GeO2. We classify PbO-SiO2 glass as a "binary network-former glass" with large amounts of free volume. © 2010 The American Physical Society.

  238. Control of interpenetration for tuning structural flexibility influences sorption properties

    Sareeya Bureekaew, Hiroshi Sato, Ryotaro Matsuda, Yoshiki Kubota, Raita Hirose, Jungeun Kim, Kenichi Kato, Masaki Takata, Susumu Kitagawa

    Angewandte Chemie - International Edition 49 (42) 7660-7664 2010年10月11日

    DOI: 10.1002/anie.201002259  

    ISSN:1433-7851

    eISSN:1521-3773

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    Transforming jungle gyms: Structural flexibility and sorption behavior can be tuned by controlling the degree of interpenetration of 3D porous coordination polymers (PCPs). The architectural connectivity of PCPs, even those that are composed of the same chemical components, has a significant impact on the structural flexibility and sorption behavior, which was confirmed by coincident XRPD/adsorption measurements. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  239. Preparation, structure analysis and enzymatic degradation of poly [(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] gel-films

    Taizo Kabe, Toshihisa Tanaka, Ken Ichi Kasuya, Kazuki Ito, Masaki Takata, Akio Takemura, Tadahisa Iwata

    Journal of Fiber Science and Technology 66 (10) 253-260 2010年10月

    DOI: 10.2115/fiber.66.253  

    ISSN:0037-9875

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    Gel-films of poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] (P(3HB-co-3HH)) with 12 mol% 3HH comonomer were prepared from a dilute solution of 1,2-dichloroethane by rapid quenching and slow drying. Uniaxial drawings were applied to the gel-films at room temperature. The gel-films were possible to stretch up to 8 times, leading to enhancements of the mechanical properties. The tensile strength, Young's modulus, and elongation to break of 8 times drawn gel-film were 151 MPa, 0.21 GPa, and 58 %, respectively. The orientation of lamella crystals in gel-films and drawn gel-films were analyzed by wide-angle and small-angle X-ray diffraction. In the drawn gel-films, a planer zigzag conformation consisting of extended molecular chains was observed. Furthermore, the lamella crystals in drawn gel-film were revealed to orient two directions, which are parallel and perpendicular to the film surface. It was indicated that a part of the oriented lamella crystal parallel to film surface rotated in the direction of perpendicular to the film surface during drawing of the gel-film. The drawings of gel-films accelerated the rate of enzymatic degradation by PHB depolymerase. The result was explained that the planer zigzag conformation in the drawn gel-films was easier to be broken down by the enzyme than the lamella crystals.

  240. Phase transitions and the role of vanadium t2g states in A V<inf>13</inf> O<inf>18</inf> (A=Sr,Ba )

    M. Ikeda, Y. Nagamine, S. Mori, J. E. Kim, K. Kato, M. Takata, T. Katsufuji

    Physical Review B - Condensed Matter and Materials Physics 82 (10) 2010年9月10日

    DOI: 10.1103/PhysRevB.82.104415  

    ISSN:1098-0121

    eISSN:1550-235X

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    We studied A V13 O18 (A=Sr,Ba), in which V ions form a face-centered-cubic lattice with periodically missing ions. It was found that there is a phase transition in both SrV13 O18 (Tc =270 K) and BaV13 O18 (Tc =200 K), where anomalies are observed in resistivity and magnetic susceptibility. Resistivity shows a contrasting behavior in the low-temperature phase between SrV13 O18 (a metallic behavior) and BaV13 O18 (an insulating behavior). By synchrotron x-ray powder-diffraction measurement, it was found that V trimerization occurs at the phase transition of SrV13 O 18. On the other hand, BaV13 O18 does not show a large change in the x-ray powder diffraction but superlattice peaks at (0 1 2 1 2) was observed in the electron diffraction. Possible orbital states of the t2g electrons in the V ions are discussed. © 2010 The American Physical Society.

  241. Present status and future perspective of synchrotron radiation research

    Masaki Takata, Masaki Yamamoto, Tetsuya Ishikawa

    Atomos 52 (9) 530-535 2010年9月

    DOI: 10.3327/jaesjb.52.9_530  

    ISSN:1882-2606

  242. Temperature responsive channel uniformity impacts on highly guest-selective adsorption in a porous coordination polymer

    Ryotaro Matsuda, Takashi Tsujino, Hiroshi Sato, Yoshiki Kubota, Kunimitsu Morishige, Masaki Takata, Susumu Kitagawa

    Chemical Science 1 (3) 315-321 2010年9月1日

    DOI: 10.1039/c0sc00272k  

    ISSN:2041-6520

    eISSN:2041-6539

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    Selective adsorption, so called "molecular sieving", is one of the significant functions of porous materials because it can play an important role in separation processes to obtain highly pure gases or petroleum. One of the next outstanding challenges of porous materials is the achievement of controllable "molecular sieving" in response to external environments. Here, we show a new temperature responsive 1-dimensional porous compound (CPL-11) which changes its structural uniformity in response to ambient temperature, which gives rise to changes in the effective pore size. As a result of the structural responsiveness, the seeming adsorption properties of CPL-11 are apparently opposite to conventional porous compounds expected from thermodynamic law, resulting in a highly selective adsorption for O2 compared to Ar. This unexpected adsorption behavior indicates that the adsorption properties can be controlled by changing the channel uniformity of a porous framework depending on the ambient temperature. © 2010 The Royal Society of Chemistry.

  243. Photoactivation of a nanoporous crystal for on-demand guest trapping and conversion

    Hiroshi Sato, Ryotaro Matsuda, Kunihisa Sugimoto, Masaki Takata, Susumu Kitagawa

    Nature Materials 9 (8) 661-666 2010年8月

    DOI: 10.1038/nmat2808  

    ISSN:1476-1122

    eISSN:1476-4660

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    porous compound with unique properties based on intrinsic nanosized space and surface functionalities is scientifically and technologically important. However, the functional species used in this context are limited to those that are sufficiently inert to not spoil the porous structures. Here, we show a new strategy to achieve a crystalline porous material with the pore surface regularly decorated with highly reactive 'bare' nitrenes that are photonically generated from stable 'dormant' precursors at will. The bare triplet nitrenes were accessible to and reacted with adsorbed oxygen or carbon monoxide molecules, which showed not only activation of the pore surface, but also a high probability of chemical trapping and conversion of guest molecules by light stimulation on demand. © 2010 Macmillan Publishers Limited. All rights reserved.

  244. A layered ionic crystal of polar Li@C<inf>60</inf> superatoms

    Shinobu Aoyagi, Eiji Nishibori, Hiroshi Sawa, Kunihisa Sugimoto, Masaki Takata, Yasumitsu Miyata, Ryo Kitaura, Hisanori Shinohara, Hiroshi Okada, Takeshi Sakai, Yoshihiro Ono, Kazuhiko Kawachi, Kuniyoshi Yokoo, Shoichi Ono, Kenji Omote, Yasuhiko Kasama, Shinsuke Ishikawa, Takashi Komuro, Hiromi Tobita

    Nature Chemistry 2 (8) 678-683 2010年8月

    DOI: 10.1038/nchem.698  

    ISSN:1755-4330

    eISSN:1755-4349

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    If the physical properties of C60 fullerene molecules can be controlled in C60 products already in use in various applications, the potential for industrial development will be significant. Encapsulation of a metal atom in the C60 fullerene molecule is a promising way to control its physical properties. However, the isolation of C60 -based metallofullerenes has been difficult due to their insolubility. Here, we report the complete isolation and determination of the molecular and crystal structure of polar cationic Li@C60 metallofullerene. The physical and chemical properties of Li@C60 cation are compared with those of pristine C60. It is found that the lithium cation is located at off-centre positions in the C60-Ih cage interior and that the [Li+ @C60] salt has a unique two-dimensional structure. The present method of purification and crystallization of C60 -based metallofullerenes provides a new C60 fullerene material that contains a metal atom. © 2010 Macmillan Publishers Limited. All rights reserved.

  245. Selective sorption of oxygen and nitric oxide by an electron-donating flexible porous coordination polymer

    Satoru Shimomura, Masakazu Higuchi, Ryotaro Matsuda, Ko Yoneda, Yuh Hijikata, Yoshiki Kubota, Yoshimi Mita, Jungeun Kim, Masaki Takata, Susumu Kitagawa

    Nature Chemistry 2 (8) 633-637 2010年8月

    DOI: 10.1038/nchem.684  

    ISSN:1755-4330

    eISSN:1755-4349

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    Porous coordination polymers are materials formed from metal ions that are bridged together by organic linkers and that can combine two seemingly contradictory properties-crystallinity and flexibility. Porous coordination polymers can therefore create highly regular yet dynamic nanoporous domains that are particularly promising for sorption applications. Here, we describe the effective selective sorption of dioxygen and nitric oxide by a structurally and electronically dynamic porous coordination polymer built from zinc centres and tetracyanoquinodimethane (TCNQ) as a linker. In contrast to a variety of other gas molecules (C2 H2, Ar, CO2, N2 and CO), O2 and NO are accommodated in its pores. This unprecedented preference arises from the concerted effect of the charge-transfer interaction between TCNQ and these guests, and the switchable gate opening and closing of the pores of the framework. This system provides further insight into the efficient recognition of small gas molecules. © 2010 Macmillan Publishers Limited. All rights reserved.

  246. Polymorphism control of superconductivity and magnetism in Cs<inf>3</inf> C<inf>60</inf> close to the Mott transition

    Alexey Y. Ganin, Yasuhiro Takabayashi, Peter Jeglič, Denis Arčon, Anton Potočnik, Peter J. Baker, Yasuo Ohishi, Martin T. McDonald, Manolis D. Tzirakis, Alec McLennan, George R. Darling, Masaki Takata, Matthew J. Rosseinsky, Kosmas Prassides

    Nature 466 (7303) 221-225 2010年7月8日

    DOI: 10.1038/nature09120  

    ISSN:0028-0836

    eISSN:1476-4687

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    The crystal structure of a solid controls the interactions between the electronically active units and thus its electronic properties. In the high-temperature superconducting copper oxides, only one spatial arrangement of the electronically active Cu 2+ units-a two-dimensional square lattice-is available to study the competition between the cooperative electronic states of magnetic order and superconductivity1. Crystals of the spherical molecular C603- anion support both superconductivity and magnetism but can consist of fundamentally distinct three-dimensional arrangements of the anions. Superconductivity in the A 3 C60 (A = alkali metal) fullerides has been exclusively associated with face-centred cubic (f.c.c.) packing of C603- (refs 2, 3), but recently the most expanded (and thus having the highest superconducting transition temperature, T c; ref. 4) composition Cs 3C60 has been isolated as a body-centred cubic (b.c.c.) packing, which supports both superconductivity and magnetic order. Here we isolate the f.c.c. polymorph of Cs3 C60 to show how the spatial arrangement of the electronically active units controls the competing superconducting and magnetic electronic ground states. Unlike all the other f.c.c. A3C60 fullerides, f.c.c. Cs3C 60 is not a superconductor but a magnetic insulator at ambient pressure, and becomes superconducting under pressure. The magnetic ordering occurs at an order of magnitude lower temperature in the geometrically frustrated f.c.c. polymorph (Néel temperature TN = 2.2 K) than in the b.c.c.-based packing (TN = 46 K). The different lattice packings of C603- change T c from 38 K in b.c.c. Cs 3C60 to 35 K in f.c.c. Cs3C60 (the highest found in the f.c.c. A3C60 family). The existence of two superconducting packings of the same electronically active unit reveals that T c scales universally in a structure-independent dome-like relationship with proximity to the Mott metal-insulator transition, which is governed by the role of electron correlations characteristic of high-temperature superconducting materials other than fullerides. © 2010 Macmillan Publishers Limited. All rights reserved.

  247. Crossover behavior of the crystal structure and the relation to magnetism in perovskite RTiO<inf>3</inf>

    K. Takubo, M. Shimuta, J. E. Kim, K. Kato, M. Takata, T. Katsufuji

    Physical Review B - Condensed Matter and Materials Physics 82 (2) 2010年7月6日

    DOI: 10.1103/PhysRevB.82.020401  

    ISSN:1098-0121

    eISSN:1550-235X

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    We found that a crossover behavior of the crystal structure at high temperatures dominates the magnetic state at low temperatures in the series of R TiO3 (R is rare earth). At the crossover temperature, which exist only in the samples that become antiferromagnetic at lower temperatures, the temperature derivative of lattice constants changes its sign, and the crossover temperature approaches zero as the Neel temperature approaches zero in the phase diagram of the ionic radius of R vs temperature. This result indicates that the orbital state of the Ti ion dominates the low-temperature magnetic state in R TiO3. © 2010 The American Physical Society.

  248. Use of side-chain incompatibility for tailoring long-range p/n heterojunctions: Photoconductive nanofibers formed by self-assembly of an amphiphilic donor-acceptor dyad consisting of oligothiophene and perylenediimide

    Wei Shi Li, Akinori Saeki, Yohei Yamamoto, Takanori Fukushima, Shu Seki, Noriyuki Ishii, Kenichi Kato, Masaki Takata, Takuzo Aida

    Chemistry - An Asian Journal 5 (7) 1566-1572 2010年7月5日

    DOI: 10.1002/asia.201000111  

    ISSN:1861-4728

    eISSN:1861-471X

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    To tailor organic p/n heterojunctions with molecular-level precision, a rational design strategy using side-chain incompatibility of a covalently connected donor-acceptor (D-A) dyad has been successfully carried out. An oligothiophene-perylenediimide dyad, when modified with triethylene glycol side chains at one terminus and dodecyl side chains at the other (2Amphi), self-assembles into nanofibers with a long-range D/A heterojunction. In contrast, when the dyad is modified with dodecyl side chains at both termini (2Lipo), ill-defined microfibers result. In steady-state measurements using microgap electrodes, a cast film of the nanofiber of 2Amphi displays far better photoconducting properties than that of the microfiber of 2Lipo. Flash-photolysis time-resolved microwave conductivity measurements, in conjunction with transient absorption spectroscopy, clearly indicate that the nanofiber of 2Amphi intrinsically allows for better carrier generation and transport properties than the microfibrous assembly of 2Lipo. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  249. Columnar liquid crystal with a spontaneous polarization along the columnar axis

    Daigo Miyajima, Fumito Araoka, Hideo Takezoe, Jungeun Kim, Kenichi Kato, Masaki Takata, Takuzo Aida

    Journal of the American Chemical Society 132 (25) 8530-8531 2010年6月30日

    DOI: 10.1021/ja101866e  

    ISSN:0002-7863

    eISSN:1520-5126

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    A fan-shaped molecule (2), carrying hydrogen-bonding amide groups in proximity to its polar aromatic core, self-assembles into a columnar liquid crystalline mesophase, which unprecedentedly possesses a spontaneous macroscopic polarization along the columnar axis. Due to its polar nature, the mesophase displays a signal of second harmonic generation (SHG), which disappears on phase transition to an isotropic melt and then retrieves its original intensity on subsequent cooling. © 2010 American Chemical Society.

  250. Solid solutions of soft porous coordination polymers: Fine-tuning of gas adsorption properties

    Tomohiro Fukushima, Satoshi Horike, Yasutaka Inubushi, Keiji Nakagawa, Yoshiki Kubota, Masaki Takata, Susumu Kitagawa

    Angewandte Chemie - International Edition 49 (28) 4820-4824 2010年6月28日

    DOI: 10.1002/anie.201000989  

    ISSN:1433-7851

    eISSN:1521-3773

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    (Figure Presented) My flexible friend: Separation of a CO2/ CH4 mixture was optimized by varying the composition of solid solutions of interdigitated 2D frameworks comprising two different isophthalate ligands (see picture). The characteristics of the solid solutions were dependent on the ligand ratio, which influenced the inherent flexibility and therefore the adsorption properties of the frameworks. © 2010 Wlley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  251. Formation of a three-dimensional network of v trimers in A2V13O22 (A=Ba, Sr)

    J. Miyazaki, K. Matsudaira, Y. Shimizu, M. Itoh, Y. Nagamine, S. Mori, J. E. Kim, K. Kato, M. Takata, T. Katsufuji

    Physical Review Letters 104 (20) 2010年5月18日

    DOI: 10.1103/PhysRevLett.104.207201  

    ISSN:0031-9007

    eISSN:1079-7114

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    We found that in A2V13O22 (A=Ba, Sr), which contains a trilayer slab of VO in the sodium-chloride structure with periodically missing ions, the trimerization of V ions occurs at 290 K (A=Ba) and 380 K (A=Sr). V trimers form a three-dimensional network, but some V ions remain untrimerized in these compounds. The suppression of magnetic susceptibility with trimerization and the existence of a Curie tail at low temperatures, together with the result of NMR measurement, indicate that the V trimers are spin singlet, whereas the untrimerized V ions have a magnetic moment; i.e., there is a spontaneous separation between nonmagnetic and magnetic ions in the crystal. © 2010 The American Physical Society.

  252. Observation of spin helicity using nonresonant circularly polarized X-ray diffraction analysis

    Hajime Sagayama, Nobuyuki Abe, Kouji Taniguchi, Taka Hisa Arima, Yuichi Yamasaki, Daisuke Okuyama, Yoshinori Tokura, Souichiro Sakai, Takeshi Morita, Takashi Komesu, Hiroyuki Ohsumi, Masaki Takata

    Journal of the Physical Society of Japan 79 (4) 2010年4月

    DOI: 10.1143/JPSJ.79.043711  

    ISSN:0031-9015

    eISSN:1347-4073

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    We have successfully detected spin chirality in prototypical multiferroic MnWO4 wherein the helical magnetic order induces ferroelectricity using a nonresonant circularly polarized X-ray diffraction technique. The intensity of the magnetic reflection from MnWO4 shows a clear difference between the right- and left-handed circular polarizations of the incident X-ray beam. The ratio of these intensities is in good agreement with theoretical predictions. The results clearly show that this technique is suitable for the investigation of spin chirality. Finally, we studied the spin chirality of another multiferroic material, DyMnO3. Possible applications of this technique are also discussed. ©2010 The Physical Society of Japan.

  253. Incommensurate guest adsorption in bellows-shaped one-dimensional channels of porous coordination polymers

    Ryotaro Matsuda, Ryo Kitaura, Yoshiki Kubota, Tatsuo C. Kobayashi, Masaki Takata, Susumu Kitagawa

    Microporous and Mesoporous Materials 129 (3) 296-303 2010年4月

    DOI: 10.1016/j.micromeso.2009.06.023  

    ISSN:1387-1811

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    Adsorption isotherms of N2, O2, CO2, and Xe on a flexible microporous coordination polymer, CPL-2 [Cu2(pzdc)2(bpy)]·(pzdc = pyrazine-2,3-dicarboxylate; bpy = 4,4′-bipyridine), possessing bellows-shaped one-dimensional channels were measured. A nonintegral number of each of the N2, O2, CO2, and Xe molecules can be accommodated in each unit pore, which indicates that all guest molecules are accommodated in the so-called "incommensurate fashion". In situ synchrotron X-ray powder diffraction patterns of CPL-2 with guest molecules were recorded. The unit cells were determined from each pattern. It was found that the host CPL-2 exhibits different crystal transformation with the accommodation of each guest molecule. This indicates that, even in the case of incommensurate adsorption, the flexible framework of a microporous coordination polymer can transform each pore to suit different guest molecules. © 2009 Elsevier Inc. All rights reserved.

  254. Atomic-level Pd-Pt alloying and largely enhanced hydrogen-storage capacity in bimetallic nanoparticles reconstructed from core/shell structure by a process of hydrogen absorption/desorption

    Hirokazu Kobayashi, Miho Yamauchi, Hiroshi Kitagawa, Yoshiki Kubota, Kenichi Kato, Masaki Takata

    Journal of the American Chemical Society 132 (16) 5576-5577 2010年4月

    DOI: 10.1021/ja1013163  

    ISSN:0002-7863

    eISSN:1520-5126

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    We have achieved the creation of a solid-solution alloy where Pd and Pt are homogeneously mixed at the atomic level, by a process of hydrogen absorption/desorption as a trigger for core (Pd)/shell (Pt) nanoparticles. The structural change from core/shell to solid solution has been confirmed by in situ powder X-ray diffraction, energy dispersive spectra, solid-state 2H NMR measurement, and hydrogen pressure-composition isotherms. The successfully obtained Pd-Pt solid-solution nanoparticles with a Pt content of 8-21 atom % had a higher hydrogen-storage capacity than Pd nanoparticles. Moreover, the hydrogen-storage capacity of Pd-Pt solid-solution nanoparticles can be tuned by changing the composition of Pd and Pt. © 2010 American Chemical Society.

  255. Shape-directed assembly of a "macromolecular barb" into nanofibers: Stereospecific cyclopolymeriztion of isopropylidene diallylmalonate

    Yasunao Miyamura, Kazushi Kinbara, Yohei Yamamoto, Vakayil K. Praveen, Kenichi Kato, Masaki Takata, Takano Atsushi, Yushu Matsushita, Eunjl Lee, Myongsoo Lee, Takuzo Aida

    Journal of the American Chemical Society 132 (10) 3292-3294 2010年3月17日

    DOI: 10.1021/ja910901e  

    ISSN:0002-7863

    eISSN:1520-5126

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    (Figure Presented) Cyclopolymerization of isopropylidene diallylmalonate (1) in CH2Cl2 using as the initiator a crystallographically defined α-diimine Pd(II) complex with a trans-azobenzene strap (trans-3) proceeds stereospecifically to give a cycloolefinic polymer that is rich in threo-disyndiotactic sequences (strich-2; syndiotactic tetrad content = 60% at -10 to 0 °C). Polymer 2, when perfectly threo-disyndiotactic, adopts a "barb"-shaped geometry with its cyclic malonate pendants sticking out alternately up and down along the rigid main chain. Under appropriate conditions, strich-2 regularly self-assembles, not only in the solid state but also in solution, into nanofibers that eventually give rise to physical gelation of halogenated solvents such as CH2Cl 2. In sharp contrast, a reference polymer 2 that is rich in threo-diisotactic sequences (itrich-2), which likely adopts a helical geometry, has poor self-assembly capability in solution and neither forms nanofibers nor induces physical gelation of CH2Cl2. Copyright © 2010 American Chemical Society.

  256. Electronic and magnetic phase diagram of superconductors, SmFeAsO <inf>1-x</inf>F<inf>x</inf>

    Yoichi Kamihara, Takatoshi Nomura, Masahiro Hirano, Jung Eun Kim, Kenichi Kato, Masaki Takata, Yasuhiro Kobayashi, Shinji Kitao, Satoshi Higashitaniguchi, Yoshitaka Yoda, Makoto Seto, Hideo Hosono

    New Journal of Physics 12 2010年3月5日

    DOI: 10.1088/1367-2630/12/3/033005  

    ISSN:1367-2630

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    A crystallographic and magnetic phase diagram of SmFeAsO 1-xFx is determined as a function of x in terms of temperature based on electrical transport and magnetization, synchrotron powder x-ray diffraction, 57Fe Mössbauer spectra (MS), and 149Sm nuclear resonant forward scattering (NRFS) measurements. MS revealed that the magnetic moments of Fe were aligned antiferromagnetically at ~144 K (TN(Fe)). The magnetic moment of Fe (MFe) is estimated to be 0.34 μB/Fe at 4.2 K for undoped SmFeAsO; MFe is quenched in superconducting F-doped SmFeAsO. 149Sm NRFS spectra revealed that the magnetic moments of Sm start to order antiferromagnetically at 5.6 K (undoped) and 4.4 K (TN(Sm)) (x = 0.069). Results clearly indicate that the antiferromagnetic (AF) Sm sublattice coexists with the superconducting phase in SmFeAsO1-xFx below T N(Sm), while the AF Fe sublattice does not coexist with the superconducting phase. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

  257. Opening of a charge gap with v trimerization in BaV10 O15

    T. Kajita, T. Kanzaki, T. Suzuki, J. E. Kim, K. Kato, M. Takata, T. Katsufuji

    Physical Review B - Condensed Matter and Materials Physics 81 (6) 2010年2月10日

    DOI: 10.1103/PhysRevB.81.060405  

    ISSN:1098-0121

    eISSN:1550-235X

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    A structural phase transition at Tc 130K in BaV10 O15 containing modified V3+ (3 d2) triangular lattices was studied. It was found that the electrical resistivity jumps by three orders of magnitude and a gap opens up in the optical conductivity spectrum at Tc. It was also found from synchrotron x-ray powder-diffraction measurement that the trimerization of the V ions occurs below Tc. These results indicate that the orbital ordering of V t2g states occurs at Tc and that induces a charge gap near the Fermi level in the electronic states of BaV10 O15. © 2010 The American Physical Society.

  258. Correlation of structure changes in the water-induced phase transitions of Poly(ethylenimine) viewed from molecular, crystal, and higher-order levels as studied by simultaneous WAXD/SAXS/Raman measurements

    Tomoko Hashida, Kohji Tashiro, Kazuki Ito, Masaki Takata, Sono Sasaki, Hiroyasu Masunaga

    Macromolecules 43 (1) 402-408 2010年1月12日

    DOI: 10.1021/ma9017857  

    ISSN:0024-9297

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    Simultaneous measurements of WAXD, SAXS, and Raman spectra have been performed during the water-induced phase transitions of poly(ethylenimine) (PEI). As is well-known, PEI transforms among four kinds of crystalline forms by absorbing water: anhydrate (El/water = 1/0), hemihydrate (1/0.5), sesquihydrate (1/1.5), and dihydrate (1/2). The chain conformation changes from double helix in the anhydrate (0) to planar-zigzag form in the hemi- (0.5), sesqui- (1.5), and dihydrates (2). The structuctural changes in the crystalline region during the water-induced phase transitions have been found to induce also the remarkable changes in the higher-order structure of stacked lamellae on the basis of the detailed comparison between WAXD and SAXS data. The anhydrate (0) composed of double helices showed the long period of 81 Å. When the anhydrate (0) started to transfer to the hemihydrate (0.5), the two types of long periods, 75 and 159 Å, were observed. The 159 Å period appeared only temporarily in the transition process from anhydrate (0) to hemihydrate (0.5). In the transition from hemihydrate (0.5) to sesquihydrate (1.5) and to dihydrate (2) the long period changed to 64 Å (0.5 and 1.5) and 61 Å (2). These SAXS profile changes have been reproduced quantitatively on the basis of a stacked lamellar structural model with paracrystalline disorder taken into consideration. © 2009 American Chemical Society.

  259. 放射光X線磁気散乱法で迫る強相関物質のスピン構造と物性

    大隅 寛幸, 有馬 孝尚, 高田 昌樹

    日本結晶学会誌 52 s17 2010年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.52.s17  

    ISSN:0369-4585

  260. Simultaneous measurements of picosecond lattice and charge dynamics in Co-Fe cyanides

    Yoshimitsu Fukuyama, Nobuhiro Yasuda, Hayato Kamioka, Jungeun Kim, Takayuki Shibata, Hitoshi Osawa, Takeshi Nakagawa, Haruno Murayama, Kenichi Kato, Yoshihito Tanaka, Shigeru Kimura, Takashi Ohshima, Hitoshi Tanaka, Masaki Takata, Yutaka Moritomo

    Applied Physics Express 3 (1) 2010年1月

    DOI: 10.1143/APEX.3.016601  

    ISSN:1882-0778

    eISSN:1882-0786

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    Simultaneous measurements of picosecond time-resolved synchrotron-radiation (SR) X-ray diffraction and femtosecond time-resolved visible absorption were performed at BL40XU beamline of SPring-8 on two films of Co-Fe cyanides, Na 0:77Co[Fe(CN)6]0:902.9H2O (NCF90) and Na0:16Co[Fe(CN)6]0:713.8H2O (NCF71). The simultaneous measurements unambiguously revealed that the photoinduced charge transfer between the Co and Fe sites causes uniform volume expansion/contraction within 100 ps. The photoinduced lattice contraction observed in the NCF71 film can be interpreted in terms of the photoinduced formation of a hidden metastable phase. © 2010 The Japan Society of Applied Physics.

  261. Multipole electron-density modelling of synchrotron powder diffraction data: The case of diamond

    H. Svendsen, J. Overgaard, R. Busselez, B. Arnaud, P. Rabiller, A. Kurita, E. Nishibori, M. Sakata, M. Takata, B. B. Iversen

    Acta Crystallographica Section A: Foundations of Crystallography 66 (4) 458-469 2010年

    DOI: 10.1107/S0108767310014236  

    ISSN:0108-7673

    eISSN:1600-5724

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    Accurate structure factors are extracted from synchrotron powder diffraction data measured on crystalline diamond based on a novel multipole model division of overlapping reflection intensities. The approach limits the spherical-atom bias in structure factors extracted from overlapping powder data using conventional spherical-atom Rietveld refinement. The structure factors are subsequently used for multipole electron-density modelling, and both the structure factors and the derived density are compared with results from ab initio theoretical calculations. Overall, excellent agreement is obtained between experiment and theory, and the study therefore demonstrates that synchrotron powder diffraction can indeed provide accurate structure-factor values based on data measured in minutes with limited sample preparation. Thus, potential systematic errors such as extinction and twinning commonly encountered in single-crystal studies of small-unit-cell inorganic structures can be overcome with synchrotron powder diffraction. It is shown that the standard Hansen-Coppens multipole model is not flexible enough to fit the static theoretical structure factors, whereas fitting of thermally smeared structure factors has much lower residuals. If thermally smeared structure factors (experimental or theoretical) are fitted with a slightly wrong radial model (s 2 p 2 instead of sp 3) the radial scaling parameters (parameters) are found to be inadequate and the error is absorbed into the atomic displacement parameter. This directly exposes a correlation between electron density and thermal parameters even for a light atom such as carbon, and it also underlines that in organic systems proper deconvolution of thermal motion is important for obtaining correct static electron densities. © 2010 International Union of Crystallography Printed in Singapore-all rights reserved.

  262. Small-angle and wide-angle X-ray scattering study on the bilayer structure of synthetic and bovine heart cardiolipins

    Hiroshi Takahashi, Tomohiro Hayakawa, Kazuki Ito, Masaki Takata, Toshihide Kobayashi

    Journal of Physics: Conference Series 247 2010年

    DOI: 10.1088/1742-6596/247/1/012021  

    ISSN:1742-6588

    eISSN:1742-6596

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    Cardiolipin (CL) is a membrane phospholipid containing four fatty acid chains. CL plays an important role in energy transformation in mitochondria. The disorder of CL biosynthesis is involved in a genetic disease, Barth syndrome. Alteration of fatty acid composition of CLs has been found in Barth syndrome patients, i.e., the decrease of unsaturated fatty acid chains. In this study, we investigated how the degree of saturation alters the structure of CL bilayers by using X-ray scattering. Bovine heart CL and two synthetic CLs were compared. Fatty acid compositions of these three CLs have different saturation. Small-angle X-ray scattering data showed that the decrease of the number of double bonds in the unsaturated fatty acid chains causes to thicken the CL bilayers. In addition, wide-angle X-ray scattering data suggested that the decrease reduces the degree of disorder of the hydrophobic region in a liquid crystalline phase. These results may be related to the dysfunction of mitochondria in Barth syndrome. © 2010 IOP Publishing Ltd.

  263. Comment on "formation of large voids in the amorphous phase-Change memory Ge2Sb2Te5 alloy"

    P. Jóvári, I. Kaban, S. Kohara, M. Takata

    Physical Review Letters 104 (1) 2010年

    DOI: 10.1103/PhysRevLett.104.019601  

    ISSN:0031-9007

    eISSN:1079-7114

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    A Comment on the Letter by Zhimei Sun, Jian Zhou, Andreas Blomqvist, Borje Johansson, and Rajeev Ahuja, Phys. Rev. Lett.PRLTAO0031-9007 102, 075504 (2009)10.1103/PhysRevLett.102.075504. The authors of the Letter offer a Reply. (See also following Comment and Reply in this issue.) © 2010 The American Physical Society.

  264. Systematic construction of porous coordination pillared-layer structures and their sorption properties

    Hirotoshi Sakamoto, Ryo Kitaura, Ryotaro Matsuda, Susumu Kitagawa, Yoshiki Kubota, Masaki Takata

    Chemistry Letters 39 (3) 218-219 2010年

    DOI: 10.1246/cl.2010.218  

    ISSN:0366-7022

    eISSN:1348-0715

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    Two novel coordination polymers, {[Cu2(pzdc)2L] ·mH2O}n where pzdc is pyrazine-2,3-dicarboxylate and L is 2,7-diazapyrene (CPL-3) and 1,2-azopyridine (CPL-4), respectively, having 3D pillared-layer structure were prepared and the compounds showed gas adsorption properties depending on L. © 2010 The Chemical Society of Japan.

  265. Room-temperature nanoimprint lithography for crystalline poly(fluoroalkyl acrylate) thin films

    Koji Honda, Masamichi Morita, Hiroyasu Masunaga, Sono Sasaki, Masaki Takata, Atsushi Takahara

    Soft Matter 6 (5) 870-875 2010年

    DOI: 10.1039/b918316g  

    ISSN:1744-683X

    eISSN:1744-6848

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    A mold with a line pattern was imprinted onto a thin film of poly{2-(perfluorooctyl)ethyl acrylate} with long crystalline fluoroalkyl groups (PFA-C8), and the nanoimprinting characteristics of PFA-C8 thin films were investigated. It was revealed that nanostructures could be imprinted on PFA-C8 at room temperature because of the weak interaction among the fluoroalkyl groups in crystallites. The nanotextured PFA-C8 film with a line pattern exhibited anisotropic wetting behavior. The anisotropic wetting behavior was attributed to the difference between the energy barriers of wetting in the direction parallel and orthogonal to the lines. Fabricated nanostructures were stable for annealing below its melting point and were stable at room temperature (RT) for several months. © 2010 The Royal Society of Chemistry.

  266. Epitaxially stabilized iridium spinel oxide without cations in the tetrahedral site

    Hiromichi Kuriyama, Jobu Matsuno, Seiji Niitaka, Masaya Uchida, Daisuke Hashizume, Aiko Nakao, Kunihisa Sugimoto, Hiroyuki Ohsumi, Masaki Takata, Hidenori Takagi

    Applied Physics Letters 96 (18) 2010年

    DOI: 10.1063/1.3374449  

    ISSN:0003-6951

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    Single-crystalline thin film of an iridium dioxide polymorph Ir2 O4 has been fabricated by the pulsed laser deposition of Li x Ir2 O4 precursor and the subsequent Li-deintercalation using soft chemistry. Ir2 O4 crystallizes in a spinel (A B2 O4) without A cations in the tetrahedral site, which is isostructural to λ -MnO2. Ir ions form a pyrochlore sublattice, which is known to give rise to a strong geometrical frustration. This Ir spinel was found to be a narrow gap insulator, in remarkable contrast to the metallic ground state of rutile-type IrO2. We argue that an interplay of a strong spin-orbit coupling and a Coulomb repulsion gives rise to an insulating ground state as in a layered perovskite Sr2 IrO4. © 2010 American Institute of Physics.

  267. Structural investigation of GeSb<inf>6</inf>Te<inf>10</inf> and GeBi <inf>6</inf>Te<inf>10</inf> intermetallic compounds in the chalcogenide homologous series

    Toshiyuki Matsunaga, Rie Kojima, Noboru Yamada, Tomoko Fujita, Kouichi Kifune, Yoshiki Kubota, Masaki Takata

    Acta Crystallographica Section B: Structural Science 66 (4) 407-411 2010年

    DOI: 10.1107/S0108768110024080  

    ISSN:0108-7681

    eISSN:0108-7681

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    The crystal structures of GeSb6Te10 and GeBi 6Te10 were scrutinized using an X-ray powder diffraction method, which revealed that these compounds crystallize in trigonally distorted cubic close-packed structures with a 51-layer period (). Each layer consists of a triangular atomic net; Te atoms occupy their own specific layers, whereas Ge, Sb and Bi atoms are located in the other layers. In these pseudobinary compounds, random atomic occupations of Ge and Sb/Bi are observed and the layers form two kinds of elemental structural blocks by their successive stacking along the c axis. These compounds can be presumed to be isostructural. It is known that the chemical formula of the chalcogenide compounds with the homologous structures found in these pseudobinary systems can be written as (GeTe)n(Sb2Te3)m or (GeTe) n (Bi2Te3) m (n, m: integer); the GeSb6Te10 and GeBi6Te10 investigated in this study, which correspond to the case in which n = 1 and m ×3, naturally have 3×l = 51-layer structures according to a formation rule l = 2n+5m commonly found in the compounds of these chalcogenide systems (l represents the number of layers in the basic structural unit). Calculations based on the density functional theory revealed that these materials are compound semiconductors with very narrow band gaps. © 2010 International Union of Crystallography Printed in Singapore - all rights reserved.

  268. High-precision time delay control with continuous phase shifter for pump-probe experiments using synchrotron radiation pulses

    Yoshihito Tanaka, Takashi Ohshima, Yoshimitsu Fukuyama, Nobuhiro Yasuda, Jungeun Kim, Hitoshi Osawa, Shigeru Kimura, Tadashi Togashi, Toru Hara, Hayato Kamioka, Yutaka Moritomo, Hitoshi Tanaka, Masaki Takata, Hidetoshi Sengoku, Eiji Nonoshita

    AIP Conference Proceedings 1234 951-954 2010年

    DOI: 10.1063/1.3463375  

    ISSN:0094-243X

    eISSN:1551-7616

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    Brilliant pulsed x-ray synchrotron radiation (SR) is useful for pump-probe experiment such as time-resolved x-ray diffraction, x-ray absorption fine structure, and x-ray spectroscopy. For laser pump-SR x-ray probe experiments, short pulsed lasers are generally synchronized to the SR master oscillator controlling the voltage for acceleration of electron bunches in an accelerator, and the interval between the laser and the SR pulses is changed around the time scale of target phenomenon. Ideal delay control produces any time delay as keeping the time-precision and pointing-stability of optical pulses at a sample position. We constructed the time delay control module using a continuous phase shifter of radio frequency signal and a frequency divider, which can produce the delayed trigger pulses to the laser without degradation of the time precision and the pointing stability. A picoseconds time-resolved x-ray diffraction experiment was demonstrated at SPring-8 storage ring for fast lattice response by femtosecond pulsed laser irradiation, and suggested the possibility of accurate sound velocity measurement. A delay control unit operating with subpicosecond precision has also been designed for femtosecond pump-probe experiments using a free electron laser at SPring-8 campus. © 2010 American Institute of Physics.

  269. Pump-probe x-ray diffraction technique for irreversible phase change materials

    Yoshimitsu Fukuyama, Nobuhiro Yasuda, Shigeru Kimura, Yoshihito Tanaka, Hitoshi Osawa, Jungeun Kim, Haruno Murayama, Yutaka Moritomo, Koshiro Toriumi, Hitoshi Tanaka, Masaki Takata

    AIP Conference Proceedings 1234 215-218 2010年

    DOI: 10.1063/1.3463176  

    ISSN:0094-243X

    eISSN:1551-7616

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    We have developed a pump-probe X-ray diffraction measurement system for a sample with irreversible reaction at BL40XU in the SPring-8. The system mainly consists of a time-resolved measurement system, a sample disk rotation system, and an X-ray microbeam system. The time-resolved measurement system gives time resolution of 50 ps in laser-pump and X-ray probe method. A sample disk rotation system for repetitive measurements was made to give a virgin sample for every measurement. The number of repetitions for one sample disk was increased by using the X-ray microbeam technique. To keep the overlap of the X-ray microbeam and the laser beam on the sample surface during the disk rotation, the sample disk rotation system was constructed by a low-eccentric spindle motor. By using this system, the pump-probe X-ray diffraction measurement was demonstrated for a crystallization process of a DVD material. © 2010 American Institute of Physics.

  270. The RIKEN materials science beamline at SPring-8: Towards visualization of electrostatic interaction

    Kenichi Kato, Raita Hirose, Michitaka Takemoto, Sunyeo Ha, Jungeun Kim, Masakazu Higuchi, Ryotaro Matsuda, Susumu Kitagawa, Masaki Takata

    AIP Conference Proceedings 1234 875-878 2010年

    DOI: 10.1063/1.3463354  

    ISSN:0094-243X

    eISSN:1551-7616

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    In order to visualize molecular interaction by the experimental electrostatic potential analysis we have optimized the optical parameters and developed the high-resolution Debye-Scherrer camera at the RIKEN materials science beamline, BL44B2 of SPring-8. For the purpose the camera was designed to be equipped with the hybrid X-ray detector system. One is the conventional detector, the imaging plate readout off-line to carry out high d (interplanar spacing)-resolution measurements and the other is the CCD detector, which can be operated in a camera at variable distances for high angle-resolution measurements. In addition we have been developing an in-situ properties measurement system to visualize the electrostatic interaction completely synchronized with material functions. © 2010 American Institute of Physics.

  271. Extremely high resolution single crystal diffractometory for orbital resolution using high energy synchrotron radiation at SPring-8

    Kunihisa Sugimoto, Hiroyuki Ohsumi, Shinobu Aoyagi, Eiji Nishibori, Chikako Moriyoshi, Yoshihiro Kuroiwa, Hiroshi Sawa, Masaki Takata

    AIP Conference Proceedings 1234 887-890 2010年

    DOI: 10.1063/1.3463359  

    ISSN:0094-243X

    eISSN:1551-7616

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    The investigation of accurate structure at charge density level will not only understand the function mechanism of physical property but also lead to design new functional materials. We have successfully installed large cylindrical camera at the BL02B1/SPring-8. In conceptual design, the image plate (IP) was selected as the detector, because such IP will not only detect wide range in one shot but also yield reliable data. In commissioning, the performance of this camera demonstrated to be suitable for the direct observation of d-electron system. © 2010 American Institute of Physics.

  272. Submicrometer single crystal diffractometry for highly accurate structure determination

    Nobuhiro Yasuda, Yoshimitsu Fukuyama, Koshiro Toriumi, Shigeru Kimura, Masaki Takata

    AIP Conference Proceedings 1234 147-150 2010年

    DOI: 10.1063/1.3463161  

    ISSN:0094-243X

    eISSN:1551-7616

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    Submicrometer single crystal diffractometry for highly accurate structure determination was developed using the extremely stable and highly brilliant synchrotron radiation from SPring-8. This was achieved using a microbeam focusing system and the submicrometer precision low-eccentric goniometer system. We demonstrated the structure analyses with 2×2×2μm3 cytidine, 600×600×300nm3 BaTiO3, and 1×1×1μm3 silicon. The observed structure factors of the silicon crystal were in agreement with the structure factors determined by the Pendellösung method and do not require absorption and extinction corrections. © 2010 American Institute of Physics.

  273. Development of an in-situ structure/photo-absorption coincident measurement system for precise structure-optical property relationship research at SPring-8

    Jungeun Kim, Kenichi Kato, Yutaka Moritomo, Masaki Takata

    AIP Conference Proceedings 1234 256-259 2010年

    DOI: 10.1063/1.3463184  

    ISSN:0094-243X

    eISSN:1551-7616

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    We have developed the structure and optical property coincident measurement system equipped with the photo-absorption system to the Large Debye-Scherrer Camera at BL44B2 of the SPring-8. Both photo-absorption detecting systems, the Si pin-photo diode for a 532 nm CW laser and the absorption spectrum covered the range of UV-IR (200∼1400 nm) for a white beam, are adopted. In order to verify the coincident measurement system, the X-ray powder diffraction and photo-absorption with the cyanide complex were performed individually and simultaneously under the temperature changes. As a result, the coincident measurement system performed successfully the one-to-one corresponding measurement between X-ray diffraction and photo-absorption. In addition, the monitoring of the photo-absorption informed us the property change of the material for the measurement condition and the sample transformation by temperature, laser etc. as well as damage by high-brilliance synchrotron radiation X-ray beam. © 2010 American Institute of Physics.

  274. "Bicontinuous cubic" liquid crystalline materials from discotic molecules: A special effect of paraffinic side chains with ionic liquid pendants

    Md Akhtarul Alam, Jin Motoyanagi, Yohei Yamamoto, Takanori Fukushima, Jungeun Kim, Kenichi Kato, Masaki Takata, Akinori Saeki, Shu Seki, Seiichi Tagawa, Takuzo Aida

    Journal of the American Chemical Society 131 (49) 17722-17723 2009年12月16日

    DOI: 10.1021/ja905373d  

    ISSN:0002-7863

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    (Chemical Equation Presented) Triphenylene (TP) derivatives bearing appropriate paraffinic side chains with imidazolium ion-based ionic liquid (IL) pendants were unveiled to display a phase diagram with liquid crystalline (LC) mesophases of bicontinuous cubic (Cubbi) and hexagonal columnar (Colh) geometries. While their phase transition behaviors are highly dependent on the length of the side chains and the size of the ionic liquid pendants, TPs with hexadecyl side chains exclusively form a Cubbi LC assembly over an extremely wide temperature range of ∼200°C from room temperature when the anions of the IL pendants are relatively small. Wide-angle X-ray diffraction analysis suggested that the Cubbi LC mesophase contains D-stacked columnar TP arrays with a plane-to-plane separation of ∼3.5 Å. Consistently, upon laser flash photolysis, it showed a transient microwave conductivity comparable to that of a Colh LC reference. © 2009 American Chemical Society.

  275. Crystallographic chirality of CsCuCl <inf>3</inf> probed by resonant circularly-polarized hard X-ray diffraction

    Yusuke Kousaka, Hiroyuki Ohsumi, Takashi Komesu, Taka Hisa Arima, Masaki Takata, Soichiro Sakai, Motoko Akita, Katsuya Inoue, Toshio Yokobori, Yuya Nakao, Emi Kaya, Jun Akimitsu

    Journal of the Physical Society of Japan 78 (12) 2009年12月

    DOI: 10.1143/JPSJ.78.123601  

    ISSN:0031-9015

    eISSN:1347-4073

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    We have observed the circular-polarization-dependent intensities of forbidden (0,0,6n ± 2) reflections at the Cu K absorption edge in the chiral crystal CsCuCl 3. The intensities for the right- and left-handed circularly-polarized incident beams interchange in CsCuCl 3 crystals with opposite chiralities. The result is well explained by a model calculation based on the anisotropic tensor susceptibility of Cu 2+ ions, taking only the electric-dipole (E1) process into account. This technique can determine crystallographic chirality by measuring the flipping ratio for only one reflection, in principle. © 2009 The Physical Society of Japan.

  276. Pressure evolution of the low-temperature crystal structure and bonding of the superconductor FeSe (Tc =37 K)

    S. Margadonna, Y. Takabayashi, Y. Ohishi, Y. Mizuguchi, Y. Takano, T. Kagayama, T. Nakagawa, M. Takata, K. Prassides

    Physical Review B - Condensed Matter and Materials Physics 80 (6) 2009年8月11日

    DOI: 10.1103/PhysRevB.80.064506  

    ISSN:1098-0121

    eISSN:1550-235X

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    α-FeSe with the PbO structure is a key member of the family of high- Tc iron pnictide and chalcogenide superconductors, as while it possesses the basic layered structural motif of edge-sharing distorted FeSe4 tetrahedra, it lacks interleaved ion spacers or charge-reservoir layers. We find that the application of hydrostatic pressure first rapidly increases Tc which attains a broad maximum of 37 K at ∼7 GPa before decreasing to 6 K upon further compression to ∼14 GPa. Complementary synchrotron x-ray diffraction at 16 K was used to measure the low-temperature isothermal compressibility of α-FeSe, revealing an extremely soft solid with a bulk modulus, K0 =30.7 (1.1) GPa and strong bonding anisotropy between interlayer and intralayer directions that transforms to the more densely packed β polymorph above ∼9 GPa. The nonmonotonic Tc (P) behavior of FeSe coincides with drastic anomalies in the pressure evolution of the interlayer spacing, pointing to the key role of this structural feature in modulating the electronic properties. © 2009 The American Physical Society.

  277. Experimentally constrained density-functional calculations of the amorphous structure of the prototypical phase-change material Ge2 Sb2 Te5

    J. Akola, R. O. Jones, S. Kohara, S. Kimura, K. Kobayashi, M. Takata, T. Matsunaga, R. Kojima, N. Yamada

    Physical Review B - Condensed Matter and Materials Physics 80 (2) 2009年8月6日

    DOI: 10.1103/PhysRevB.80.020201  

    ISSN:1098-0121

    eISSN:1550-235X

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    Phase change materials involve the rapid and reversible transition between nanoscale amorphous (a-) and crystalline (c-) spots in a polycrystalline film and play major roles in the multimedia world, including nonvolatile computer memory. The materials of choice are alloys of Ge, Sb, and Te, e.g., Ge2 Sb2 Te5 (GST) in digital versatile disk-random access memory. There has been much speculation about the structure of a- GST, but no model has yet received general acceptance. Here we optimize the structure by combining the results of density-functional calculations with high-energy x-ray diffraction data and x-ray photoelectron spectroscopy (XPS) measurements of the electronic densities of states to determine the structure. The structure agrees very well with available experimental data, including the differences in the XPS data between the amorphous and crystalline structures. © 2009 The American Physical Society.

  278. Porous coordination polymer with pyridinium cationic surface, [Zn <inf>2</inf>(tpa)<inf>2</inf>(cpb)]

    Masakazu Higuchi, Daisuke Tanaka, Satoshi Horike, Hirotoshi Sakamoto, Kohei Nakamura, Yohei Takashima, Yuh Hijikata, Nobuhiro Yanai, Jungeun Kim, Kenichi Kato, Yoshiki Kubota, Masaki Takata, Susumu Kitagawa

    Journal of the American Chemical Society 131 (30) 10336-10337 2009年8月5日

    DOI: 10.1021/ja900373v  

    ISSN:0002-7863

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    (Chemical Equation Presented) We have synthesized a porous coordination polymer containing a pyridinium cation as an organic linker and have investigated the methanol absorptive ability of the pyridinium cationic surface. The result implies that the pyridinium cationic surface participates in the strong adsorption of methanol. © 2009 American Chemical Society.

  279. Metal-ion-dependent gas sorptivity of elastic layer-structured MOFs

    Atsushi Kondo, Ayako Chinen, Hiroshi Kajiro, Tomohiro Nakagawa, Kenichi Kato, Masaki Takata, Yoshiyuki Hattori, Fujio Okino, Tomonori Ohba, Katsumi Kaneko, Hirofumi Kanoh

    Chemistry - A European Journal 15 (31) 7549-7553 2009年8月3日

    DOI: 10.1002/chem.200901208  

    ISSN:0947-6539

    eISSN:1521-3765

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    Gas adsorptivities of elastic layer-structured (ELS) metal-organic frameworks (MOFs) were analyzed using different metal ions. Single-crystal analyses of ELM-12 (Cu) and ELM-22 (Co) showed that each metal is coordinated by four bpy ligands in equatorial positions and two OTf anions in axial positions in an octahedral geometry to form quite similar two-dimensional square-grid sheets. ELM-12 (Cu) undergoes structural transformation under vacuum heating and its interlayer distances decrease when the hydrogen-bonding networks with and without guest molecules are changed. The weight of the metal species is one of the most important factors impacting the amount of adsorption on the rigid MOFs. The results reveal that by controlling the coordination field of a metal ion the gas adsorptivity of the flexible can be altered and ELMs can be potentially utilized for effective gas separation and storage.

  280. Core/shell structure of ferroelectric (Ba<inf>0.94</inf>Ca <inf>0.06</inf>)TiO<inf>3</inf> grains

    Yoshihiro Iwahori, Hiroshi Tanaka, Masaki Takata, Yoshihiro Terado, Chikako Moriyoshi, Yoshihiro Kuroiwa

    Journal of the Korean Physical Society 55 (2 PART 1) 830-834 2009年8月

    DOI: 10.3938/jkps.55.830  

    ISSN:0374-4884

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    The crystal structure of ferroelectric (Ba0.94Ca 0.06)TiO3 (BCT) with small grains on an average of 1-μm in size has been investigated by using high-energy synchrotron-radiation powder-diffraction. A core/shell structure model, in which the grain consists of a core with tetragonal symmetry covered all over with a thin tetragonal shell with low tetragonality, is proposed and provides a markedly contrast with the core/shell structure of pure BaTiO3, which is generally known to have a shell with cubic symmetry. The higher permittivity of BCT is attributed to the characteristic shell structure with tetragonal symmetry. A change in the chemical bonding nature of BCT on the ferroelectric phase transition is clearly demonstrated in the electron charge density map.

  281. A new method for evaluating the electrostatic potential by using a MEM X-Ray diffraction analysis

    Hiroshi Tanaka, Yoshihiro Kuroiwa, Masaki Takata

    Journal of the Korean Physical Society 55 (2 PART 1) 803-806 2009年8月

    DOI: 10.3938/jkps.55.803  

    ISSN:0374-4884

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    Recently, a new method was proposed for evaluating the electrostatic potential in crystalline solids from X-ray diffraction data. It is based on the electron charge density, which is analyzed by using the maximum entropy method (MEM) and Ewald's technique. The algorithm is almost parameter-free, and the electrostatic potential can be evaluated even by those with little or no experience. In this article, the method is reviewed briefly, and an application to a typical ionic crystal, NaCl, is introduced.

  282. Molecular aggregation state and photovoltaic properties of chlorophyll-doped conducting poly(3-hexylthiophene)/MCM-41 nanocomposites

    Weng On Yah, Zhe Wang, Hideyuki Otsuka, Kenichi Kato, Jungeun Kim, Masaki Takata, Atsushi Takahara

    ACS Applied Materials and Interfaces 1 (7) 1544-1552 2009年7月29日

    DOI: 10.1021/am9002099  

    ISSN:1944-8244

    eISSN:1944-8252

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    Chlorophyll (Chl) was immobilized into a 1,4-butanediol-modified MCM-41 (BMCM-41) intercalated by poly(3-hexylthiophene) (P3HT) to form BMCM-41/P3HT/Chl nanocomposites having P3HT contents of 10, 30, 60, and 90 wt % from a solution-casting method. Wide-angle X-ray diffraction and transmission electron microscopy studies indicate that the pore structure of MCM-41 was retained after surface modification and a subsequent P3HT intercalation process. Scanning electron microscopy images showed that the BMCM-41 nanoparticles dispersed into the polymer matrix of BMCM-41/P3HT/Chl, and the sample with 10 wt % P3HT content gives the most homogeneous nanoparticle dispersion. Nitrogen adsorption?desorption results confirmed that the P3HT intercalation and Chl immobilization inside the BMCM-41 mesopore were successfully carried out. The pore volume and surface area of BMCM-41 decreased significantly when the amount of P3HT was increased from 10 to 90 wt %. The UV?vis study showed a blue shift of the φ?φ* transition band of P3HT in the spectra of BMCM-41/P3HT/Chl nanocomposites. The FT-IR study indicates an increase of the thiophene ring stretching and a decrease of the C - O stretching when P3HT and Chl were inside the mesopore. The photovoltaic property of Chl-doped P3HT was improved significantly upon the addition of BMCM-41 nanoparticles, and BMCM-41/P3HT-10/Chl exhibits the highest incident photon-to-current conversion efficiency of 7.16%. © 2009 American Chemical Society.

  283. Relationship between morphological change and crystalline phase transitions of polyethylene-poly(ethylene oxide) diblock copolymers. 3. dependence of morphological transition phenomena on the PE/PEO segmental lengths and its possible origins

    Weiyu Cao, Kohji Tashiro, Hiroyasu Masunaga, Sono Sasaki, Masaki Takata

    Journal of Physical Chemistry B 113 (25) 8495-8504 2009年6月25日

    DOI: 10.1021/jp901442a  

    ISSN:1520-6106

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    By measurement of the small-angle and wide-angle X-ray scatterings and infrared and Raman spectra and thermal data, microphase separation phenomena have been investigated for a series of polyethylene-poly(ethylene oxide) diblock copolymer (PE-b-PEO) in both the heating and cooling processes and compared with the structural changes occurring inside the PE and PEO domains. The complicated morphological changes between lamella, perforated lamella, gyroid, cylinder, and sphere phases were detected for the copolymer with relatively short PE segments. The orthorhombic crystalline structure of PE was kept unchanged in the lamella-togyroid transition. When the PE orthorhombic phase transformed to the pseudohexagonal or rotator phase, the gyroid morphology changed to the cylinder. On the other hand, the diblock copolymer with relatively longPE segment was found to show only the lamellar morphology, in which the order-disorder structural transition between the orthorhombic and pseudohexagonal phases occurred in the PE crystal region. As a possibility, the large difference in morphological change between the copolymers with short and long PE segments has been ascribed to the difference in thermal mobility of PE segments, which is controlled by the conformation of chains and their packing mode, i.e., an extended chain or a folded chain. The extended chains may move thermally and actively along the interfacial boundary in addition to the librational motion around the chain axis, resulting in a variety of morphological changes, whereas the thermal motion of the folded chains may be suppressed because of the geometrical constraint and does not cause such a large-scale morphological change from the lamellar structure. This concept, a thermal activity and geometrical constraint, is considered to be quite important in the interpretation of complicated morphological changes observed for many crystalline-amorphous and crystalline-crystalline diblock copolymers when viewed from the molecular level. © 2009 American Chemical Society.

  284. Isothermal crystallization behavior of isotactic polypropylene H/D blends as viewed from time-resolved FTIR and synchrotron SAXS/WAXD measurements

    Kummetha Raghunatha Reddy, Kohji Tashiro, Takashi Sakurai, Noboru Yamaguchi, Sono Sasaki, Hiroyasu Masunaga, Masaki Takata

    Macromolecules 42 (12) 4191-4199 2009年6月23日

    DOI: 10.1021/ma900265u  

    ISSN:0024-9297

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    The melt isothermal crystallization behavior has been investigated for a series of blend samples of deuterated (D) and hydrogenated (H) species of isotactic polypropylene by means of time-resolved Fourier transform infrared (FTIR) spectral measurement and simultaneous small-angle X-ray scattering (SAXS)/wide-angle X-ray diffraction (WAXD) measurements using synchrotron radiation source in SPring-8. The SAXS data collected were analyzed in the three different time regions. The Guinier plot in the early stage of crystallization gave the average size of isolated domains formed in the melt. In the middle stage, the correlation between these domains was analyzed using the Debye - Bueche equation. In the later stage of crystallization, the correlation function was calculated to estimate the degree of crystallinity and the long period of the stacked lamellae. The IR data analysis clarified the formation process of regular helical chains in the isothermal crystallization phenomenon. The combination of FTIR, WAXD, and SAXS data has revealed a concrete structural evolution process as follows: (i) In the early stage, the short helices start to be formed, and they gather together to create anisolated domain of about 330 Å radius of gyration, (ii) The domain size decreases gradually to about 300 Å, and (iii) these domains start to have some weak correlation to each other with ca. 300 Å correlation length, (iv) In these domains, the regular chain segments grow to longer helices, and the correlation distance becomes shorter to ca. 200 Å, and finally, (v) the stacked lamellae with long period of ca. 200 Å are formed and stabilized. The crystallization behavior of the D/H 50/50 blend sample was also investigated, and the origin of cocrystallization phenomenon has been discussed. © 2009 American Chemical Society.

  285. Size-controlled stabilization of the superionic phase to room temperature in polymer-coated AgInanoparticles

    Rie Makiura, Takayuki Yonemura, Teppei Yamada, Miho Yamauchi, Ryuichi Ikeda, Hiroshi Kitagawa, Kenichi Kato, Masaki Takata

    Nature Materials 8 (6) 476-480 2009年6月

    DOI: 10.1038/nmat2449  

    ISSN:1476-1122

    eISSN:1476-4660

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    Solid-state ionic conductors are actively studied for their large application potential in batteries and sensors. From the view of future nanodevices, nanoscaled ionic conductors are attracting much interest. Silver iodide (AgI) is a well-known ionic conductor for which the high-temperature α-phase shows a superionic conductivity greater than 1 1 cm 1 (ref.6). Below 147 C, α-AgI undergoes a phase transition into the poorly conducting Β- and γ-polymorphs, thereby limiting its applications. Here, we report the facile synthesis of variable-size AgI nanoparticles coated with poly-N-vinyl-2-pyrrolidone (PVP) and the controllable tuning of the α- to Β-/γ-phase transition temperature (Tc). Tc shifts considerably to lower temperatures with decreasing nanoparticle size, leading to a progressively enlarged thermal hysteresis. Specifically, when the size approaches 10-11 nm, the α-phase survives down to 30 Cthe lowest temperature for any AgI family material. We attribute the suppression of the phase transition not only to the increase of the surface energy, but also to the presence of defects and the accompanying charge imbalance induced by PVP. Moreover, the conductivity of as-prepared 11 nm Β-/γ-AgI nanoparticles at 24 C is 1.5×10 2 1 cm 1 the highest ionic conductivity for a binary solid at room temperature. The stabilized superionic phase and the remarkable transport properties at a practical temperature reported here suggest promising applications in silver-ion-based electrochemical devices. © 2009 Macmillan Publishers Limited. All rights reserved.

  286. Structure and the mechanism of rapid phase change in amorphous Ge <inf>2</inf>Sb<inf>2</inf>Te<inf>2</inf>

    M. Takata, Y. Tanaka, K. Kato, F. Yoshida, Y. Fukuyama, N. Yasuda, S. Kohara, H. Osawa, T. Nakagawa, J. Kim, H. Murayama, S. Kimura, H. Kamioka, Y. Moritomo, T. Matsunaga, R. Kojima, N. Yamada, T. Ohshima, H. Tanaka

    Physics and Chemistry of Glasses: European Journal of Glass Science and Technology Part B 50 (3) 205-211 2009年6月

    ISSN:0031-9090

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    Understanding the mechanism of rapid phase change process in DVD (digital versatile disc) materials is one of the important topics in materials science, and hence numerous studies investigating the phase change process as well as structural analysis of the crystal and amorphous phases have been reported. Nevertheless, the mechanism of rapid phase change is still unclear, owing to the lack of detailed structure analysis, in particular on the amorphous phase and its crystallisation process. We have studied the amorphous structure of Ge 2Sb2Te5 and the crystallisation process by high energy synchrotron x-ray diffraction with the aid of structure modelling and time-resolved synchrotron x-ray diffraction, in order to obtain key information for revealing the rapid phase change mechanism. We found a large fraction of 4-fold and 6-fold rings in the atomic configuration of the amorphous phase. Intriguingly the bond angle distributions of rings exhibit a peak at approximately 90°, which corresponds to that in the crystal phase. Therefore, it is suggested that the 4-fold and 6-fold rings are nuclei for crystallisation. Furthermore, time-resolved x-ray diffraction measurements combined with photoreflectivity measurements during the crystallisation of the amorphous phase suggest that the crystallisation of Ge2Sb 2Te5 can be explained by a nucleation driven process. We conclude that a large amount of nuclei is the reason for rapid crystallisation in Ge2Sb2Te5 with a nucleation driven process.

  287. High-pressure (up to 10.7 GPa) crystal structure of single-component molecular metal [Au(tmdt)<inf>2</inf>]

    Yoshinori Okano, Biao Zhou, Hishashi Tanaka, Takafumi Adachi, Yasuo Ohishi, Masaki Takata, Shinobu Aoyagi, Eiji Nishibori, Makoto Sakata, Akiko Kobayashi, Hayao Kobayashi

    Journal of the American Chemical Society 131 (20) 7169-7174 2009年5月27日

    DOI: 10.1021/ja9010018  

    ISSN:0002-7863

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    The crystal structure of the single-component molecular metal [Au(tmdt)2] was examined at pressures up to 10.7 GPa In order to examine whether the high-pressure structure reflects the crystal's metallic nature. Crystal structure analyses were performed at 0.2, 0.8, 1.3, 3.0, 5.5, and 10.7 GPa on the basis of the powder X-ray diffraction data obtained by using the synchrotron radiation source SPring-8 The unit cell volume at 10.7 GPa was ̃75% of the Initial volume, Indicating that [Au(tmdt)2] Is a 'soft material' like a typical molecular crystal In spite of Its metallic nature. The pressure dependences of the bond lengths of the Au(tmdt)2 molecule were found to be ̃1 order of magnitude smaller than those of the Intermolecular atomic distances. These results seem to Justify the commonly accepted conjecture that the molecule usually behaves almost like a rigid body up to a fairly high pressure. It was found that the anisotropy of the lattice compression of the Insulating I2 crystal below 20 GPa can be essentially Interpreted on the basis of a very simple 'Interatomic repulsion model, which assumes that the molecules In the crystal are packed such that as far as possible, an Increase In the Interatomic repulsions between neighboring molecules Is avoided. However, the maximum decrease In the Intermolecular distance In [Au(tmdt)2] was observed along the a direction although there were many Intermolecular S-"S contacts shorter than the van der Waals distance (3.70 A) along this direction. The shortest Intermolecular S-"S distance was 2.73 A at 10.7 GPa, which Is ̃1 A shorter than the S-"S van der Waals distance (3.70 A). The crystal lattice of [Au(tmdt)2] Is considered to be stabilized by the enhancement of the Intermolecular overlapping of the conduction molecular orbitais having large amplitudes on peripheral S atoms. Although the crystal Is composed of 'Isolated molecules' like a typical Insulating molecular crystal, Its compressibility behavior seems to reflect Its metallic nature. 2009 American Chemical Society.

  288. Polymerization of phenylacetylene by rhodium complexes within a discrete space of apo-ferritin

    Satoshi Abe, Kunio Hirata, Takafumi Ueno, Kazuhide Morino, Nobutaka Shimizu, Masaki Yamamoto, Masaki Takata, Eiji Yashima, Yoshihito Watanabe

    Journal of the American Chemical Society 131 (20) 6958-6960 2009年5月27日

    DOI: 10.1021/ja901234j  

    ISSN:0002-7863

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    Polymerization reactions of phenylacetylene derivatives are promoted by rhodium complexes within the discrete space of apo-ferritin in aqueous media. The catalytic reaction provides polymers with restricted molecular weight and a narrow molecular weight distribution. These results suggest that protein nanocages have potential for use as various reaction spaces through immobilization of metal catalysts on the interior surfaces of the protein cages. Copyright © 2009 American Chemical Society.

  289. Impact of orbital degrees of freedom on geometrical frustration in the kagome-like magnet SrVx Ga12-x O19

    J. Miyazaki, T. Sonehara, D. Akahoshi, H. Kuwahara, J. E. Kim, K. Kato, M. Takata, T. Katsufuji

    Physical Review B - Condensed Matter and Materials Physics 79 (18) 2009年5月1日

    DOI: 10.1103/PhysRevB.79.180410  

    ISSN:1098-0121

    eISSN:1550-235X

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    We studied kagome-like magnets, SrVx Ga12-x O19 with V3+ (3 d2 in the triply degenerate t2g states), as a geometrically frustrated spin system with orbital degrees of freedom. We observed a suppression of low-temperature spin entropy and an anomalous contraction of the V triangles on the kagome lattice, which can be regarded as the V trimerization with spin-singlet formation. This result, which is in clear contrast to their Cr3+ (3 d3) analogs exhibiting a spin-liquid behavior, indicates a substantial impact of orbitals on geometrically frustrated magnets. © 2009 The American Physical Society.

  290. process of accumulation of metal ions on the interior surface of apo-ferritin: Crystal structures of a series of apo-ferritins containing variable quantities of pd(ii) ions

    Takafumi Ueno, Mizue Abe, Kunio Hirata, Satoshi Abe, Masako Suzuki, Nobutaka Shimizu, Masaki Yamamoto, Masaki Takata, Yoshihito Watanabe

    Journal of the American Chemical Society 131 (14) 5094-5100 2009年4月

    DOI: 10.1021/ja806688s  

    ISSN:0002-7863

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    Accumulation of metal ions on protein surfaces is an important subject in the field of materials science because these processes are applicable to the preparation of bioinspired inorganic materials. While previous studies related to this subject have focused on the preparation of nanomaterials using protein scaffolds, the detailed processes of metal ion deposition and metal core formation on a protein surface require clarification. Elucidation of the coordination structures of multinuclear metal binding sites on proteins at an early stage as well as intermediate and fully occupied stages of the metal ion deposition will help us to understand the reaction mechanisms so that desirable inorganic materials can be prepared using protein scaffolds. In this Article, we report on the detailed processes of accumulation of Pd(II) ions demonstrated by a series of X-ray crystal structural analyses of apo-ferritin (apo-Fr), an iron storage protein, containing different amounts of Pd(II) ions in the protein cage. We have identified the specific binding sites of Pd(II) ions and analyzed the dynamic changes in the coordination structure by a combination of the crystal structures and ICP quantitative analyses of apo-Fr containing low, intermediate, and high content of Pd(II) ions. Our studies on PdII .apo-Frs provide intriguing implications for the preparation of many other inorganic materials using protein surfaces. © 2009 American Chemical Society.

  291. Guest-host interaction of K0.34 Co [Fe (CN) 6] 0.75 z H2 O as investigated by a charge-density analysis

    J. E. Kim, K. Kato, M. Takata, T. Shibata, Y. Moritomo

    Physical Review B - Condensed Matter and Materials Physics 79 (13) 2009年4月

    DOI: 10.1103/PhysRevB.79.132105  

    ISSN:1098-0121

    eISSN:1550-235X

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    Charge-density level structure was determined in a prototypical nanoporous material with strong guest-host interaction, K0.34 Co [Fe (CN) 6] 0.75 z H2 O (z=3.6 and 2.7). We determined atomic coordinates and occupancies (g) of three kinds of oxygen sites of guest waters, i.e., zeolite water, ligand water, and off-axis water, as a function of z. The variation in g against z indicates easily removable nature of the zeolite and off-axis waters, and robust coordination bond with the ligand water. Significant change in the charge density of the host-NC-Fe-CN-Co-NC-Fe-CN-lattice revealed hybridization effect between the off-axis water and the adjacent Co atom. © 2009 The American Physical Society.

  292. The disorder-free non-BCS superconductor CS<inf>3</inf>C<inf>60</inf> emerges from an antiferromagnetic insulator parent state

    Yasuhiro Takabayashi, Alexey Y. Ganin, Peter Jeglič, Denis Arčon, Takumi Takano, Yoshihiro Iwasa, Yasuo Ohishi, Masaki Takata, Nao Takeshita, Kosmas Prassides, Matthew J. Rosseinsky

    Science 323 (5921) 1585-1590 2009年3月20日

    DOI: 10.1126/science.1169163  

    ISSN:0036-8075

    eISSN:1095-9203

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    The body-centered cubic A15-structured cesium fulleride Cs 3C60 is not superconducting at ambient pressure and is free from disorder, unlike the well-studied face-centered cubic A 3C60 alkali metal fulleride superconductors. We found that in Cs3C60, where the molecular valences are precisely assigned, the superconducting state at 38 kelvin emerges directly from a localized electron antiferromagnetic insulating state with the application of pressure. This transition maintains the threefold degeneracy of the active orbitals in both competing electronic states; it is thus a purely electronic transition to a superconducting state, with a dependence of the transition temperature on pressure-induced changes of anion packing density that is not explicable by Bardeen-Cooper-Schrieffer (BCS) theory.

  293. Development of picosecond time-resolved microbeam X-ray diffraction technique for investigation of optical recording process

    Yoshihito Tanaka, Yoshimitsu Fukuyama, Nobuhiro Yasuda, Jungeun Kim, Haruno Murayama, Shinji Kohara, Hitoshi Osawa, Takeshi Nakagawa, Shigeru Kimura, Kenich Kato, Fumiko Yoshida, Hayato Kamioka, Yutaka Moritomo, Toshiyuki Matsunaga, Rie Kojima, Noboru Yamada, Koshiro Toriumi, Takashi Ohshima, Hitoshi Tanaka, Masaki Takata

    Japanese Journal of Applied Physics 48 (3 PART 2) 2009年3月

    DOI: 10.1143/JJAP.48.03A001  

    ISSN:0021-4922

    eISSN:1347-4065

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    A time-resolved structural investigation of the data storage process in a digital versatile disk (DVD) or Blu-ray disk media is desired for better understanding of the fast phase-change mechanism for designing a higher performance optical recording material. Thus, the development of an in situ structural observation technique at the picosecond level has been carried out for the investigation of the fast phase-change phenomena using synchrotron radiation pulsed X-rays and synchronized femtosecond laser irradiation. Then, for Ge2Sb2Te5 (GST) and Ag3:5In3:8Sb75:0Te17:7 (AIST), the technique has been applied to a snapshot of X-ray diffraction pattern in the nanosecond crystallization process from the amorphous to the crystal phase, which corresponds to the erasing process of the DVD recording system. The key to success of the time-resolved experiment was to optimize the measurement timing system efficiency for both sufficient counting statistics, i.e., counting quantity and precision of time resolution, i.e., counting quality. Our time-resolved experimental system has sufficient accuracy, so that our previous study showed a significant difference in the crystal growth process between GST and AIST, indicating that the crystal growth process is key to fast phase change. To increase the precision of data in terms of signal-to-noise ratio and counting statistics, we developed a highly repetitive pump-probe measurement system combined with an X-ray microbeam technique providing high counting quantity, and used it to demonstrate a snapshot of an X-ray diffraction profile of GST. The measurement system has a time resolution of 50 ps and a 1 kHz repetition rate. Our development of the technique to take a snapshot for the structural visualization of phase-change phenomena with the time-resolved microbeam X-ray diffraction is described. © 2009 The Japan Society of Applied Physics.

  294. Relationship between morphological change and crystalline phase transitions of polyethylene-poly(ethylene oxide) diblock copolymers, revealed by the temperature-dependent synchrotron WAXD/SAXS and infrared/raman spectral measurements

    Cao Weiyu, Kohji Tashiro, Makoto Hanesaka, Shinichi Takeda, Hiroyasu Masunaga, Sono Sasaki, Masaki Takata

    Journal of Physical Chemistry B 113 (8) 2338-2346 2009年2月26日

    DOI: 10.1021/jp8092435  

    ISSN:1520-6106

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    The phase transition behaviors of low-molecular-weight polyethylene- poly(ethylene oxide) (PE-b-PEO) diblock copolymers with the monomeric units of PE/PEO = 17/40 and 39/86 have been successfully investigated through the temperature-dependent measurements of wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), infrared and Raman spectra, as well as thermal analysis. These diblock copolymers had been believed to show only order-to-disorder transition of lamellar morphology in a wide temperature region, but it has been found here for the first time that this copolymer clearly exhibits the three stages of transitions among lamella, gyroid, cylinder, and spherical phases in the heating and cooling processes. The WAXD and IR/Raman spectral measurements allowed us to relate these morphological changes to the microscopic changes in the aggregation states of PEO and PE segments. In the low-temperature region the PEO segments form the monoclinic crystal of (7/2) helical chain conformation and the PE segments of planar-zigzag form take the orthorhombic crystalline phase. These crystalline lamellae of PEO and PE segments are alternately stacked with the long period of 165 Å. In a higher temperature region, where the PEO crystalline parts are on the way of melting but the PE parts are still in the orthorhombic phase, the gyroid morphology is detected in the SAXS data. By heating further, the gyroid morphology changes to the hexagonally packed cylindrical morphology, where the orthorhombic phase of PE segments is gradually disordered because of thermally activated molecular motion and finally transforms to the pseudohexagonal or rotator phase. Once the PE segments are perfectly melted, the higher-order structure changes from the cylinder to the spherical morphology. These morphological transitions might relate to the thermally activated motions of two short chain segments of the diblock copolymer, although the details of the transition mechanism are unclear at the present stage. © 2009 American Chemical Society.

  295. Comprehensive structural study of glassy and metastable crystalline BaTi<inf>2</inf>O<inf>5</inf>

    Jianding Yu, Shinji Kohara, Keiji Itoh, Shunsuke Nozawa, Satoru Miyoshi, Yasutomo Arai, Atsunobu Masuno, Hiraki Taniguchi, Mitsuru Itoh, Masaki Takata, Toshiharu Fukunaga, Shin Ya Koshihara, Yoshihiro Kuroiwa, Shinichi Yoda

    Chemistry of Materials 21 (2) 259-263 2009年1月27日

    DOI: 10.1021/cm802483w  

    ISSN:0897-4756

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    The structures of glassy and metastable crystalline BaTi2O5 fabricated by the containerless method were comprehensively investigated by combined X-ray and neutron diffractions, XANES analyses, and computer simulations. The three-dimensional atomic structure of glassy BaTi 2O5 (g-BaTi2O5), simulated by Reverse Monte Carlo (RMC) modeling on diffraction data, shows that extremely distorted TiO5polyhedra interconnected with both corner- and edge-shared oxygen formed a higher packing density structure than that of conventional silicate glass linked with only corner-sharing of SiO4 polyhedra. In addition, XANES measurement revealed that five-coordinated TiO5 polyhedra were formable in the crystallized metastable α- and β-BaTi2O5 phases. The structure of metastable β-BaTi2O5 was solved by ab initio calculation, and refined by Rietveld refinement as group Pnma with unit lattices a = 10.23784(4) A, b = 3.92715(1) A, c = 10.92757(4) A. Our results show that the glass-forming ability enhanced by containerless processing, not by "strong glass former", fabricated new bulk oxide glasses with novel structures and properties. © 2009 American Chemical Society.

  296. Control of charge transfer phase transition and ferromagnetism by photoisomerization of spiropyran for an organic-inorganic hybrid system, (SP)[Fe<inf>II</inf>Fe<inf>IlI</inf>(dto)<inf>3</inf>] (SP = spiropyran, dto = C<inf>2</inf>O<inf>2</inf>S<inf>2</inf>)

    Noriyuki Kida, Masanori Hikita, Izuru Kashima, Masashi Okubo, Miho Itoi, Masaya Enomoto, Kenichi Kato, Masaki Takata, Norimichi Kojima

    Journal of the American Chemical Society 131 (1) 212-220 2009年1月14日

    DOI: 10.1021/ja806879a  

    ISSN:0002-7863

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    Iron mixed-valence complex, (n-G3H7) 4N[FellFelll(dto)3](dto = C 2O2S2), shows a spin entropy- driven phase transition called charge transfer phase transition in [FellFe lll(dto)3]-∞ around 120 K and a ferromagnetic transition at 7 K. These phase transitions remarkably depend on the hexagonal ring size in the two-dimensional honeycomb network structure of [Fe lllllm(dto)3]-∞ In order to control the magnetic properties and the electronic state in the dto-bridged iron mixed-valence system by means of photoirradiation, we have synthesized a photosensitive organic-inorganic hybrid system, (SP)[FellFe lll(dto)3](SP = spiropyran), and investigated the photoinduced effect on the magnetic properties. Upon UV irradiation at 350 nm, a broad absorption band between 500 and 600 nm appears and continuously increases with the photoirradiation time, which implies that the UV irradiation changes the structure of spiropyran from the closed form to the open one in solid state. The photochromism in spiropyran changes the ferromagnetic transition temperature from 5 to 22 K and the coercive force from 1400 to 6000 Oe at 2 K. In this process, the concerted phenomenon coupled with the charge transfer phase transition in [FellFelll(dto)3]-∞ and the photoisomerization of spiropyran is realized. © 2009 American Chemical Society.

  297. Liquid crystalline corannulene responsive to electric field

    Daigo Miyajima, Kentaro Tashiro, Fumito Araoka, Hideo Takezoe, Jungeun Kim, Kenichi Kato, Masaki Takata, Takuzo Aida

    Journal of the American Chemical Society 131 (1) 44-45 2009年1月14日

    DOI: 10.1021/ja808396b  

    ISSN:0002-7863

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    An amide-appended corannulene derivative (3) with tribranched paraffinic side chains self-assembles into a hexagonal columnar liquid crystalline (LC) mesophase over a wide temperature range from 154 to -10 °C. In contrast with columnar LC assemblies of planar polycyclic aromatic hydrocarbons, the LC assembly of nonplanar 3 responds to an applied electric field and can align homeotropically to the electrode surface. Even after the electric field is switched off, this alignment is memorized for a long period of time unless the material is heated above the clearing temperature. Copyright © 2009 American Chemical Society.

  298. Photoinduced dynamics of prussian blue type cyanide

    Y. Moritomo, T. Nakagawa, Y. Fukuyama, N. Yasuda, H. Oosawa, J. E. Kim, H. Kamioka, K. Kato, Y. Tanaka, S. Kimura, F. Nakada, S. Ohkoshi, H. Tanaka, M. Takata

    Journal of Physics: Conference Series 148 2009年

    DOI: 10.1088/1742-6596/148/1/012028  

    ISSN:1742-6588

    eISSN:1742-6596

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    Charge and lattice dynamics has been investigated for Na 0.79Co[Fe(CN)6]0.902.9H2O film at 300 K by means of the time-resolved x-ray diffraction apparatus coupled with the in situ time-resolved absorption measurement. We observed an uniform lattice expansion whose relaxation time is ∼ 40 ns. Based on the close correlation between the charge and lattice dynamics, the lattice expansion is ascribed to the photo-created charge-transferred Co2+ - Fe3+ state. © 2009 IOP Publishing Ltd.

  299. Structural evolution in the isothermal crystallization process of the molten nylon 10/10 traced by time-resolved infrared spectral measurements and synchrotron SAXS/WAXD measurements

    Kohji Tashiro, Asami Nishiyama, Sawako Tsuji, Tomoko Hashida, Makoto Hanesaka, Shinichi Takeda, Cao Weiyu, Kummetha Raghunatha Reddy, Hiroyasu Masunaga, Sono Sasaki, Kazuki Ito, Masaki Takata

    Journal of Physics: Conference Series 184 2009年

    DOI: 10.1088/1742-6596/184/1/012002  

    ISSN:1742-6588

    eISSN:1742-6596

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    The structural evolution in the isothermal crystallization process of nylon 10/10 from the melt has been clarified concretely on the basis of the time-resolved infrared spectral measurement as well as the synchrotron wide-angle and small-angle X-ray scattering measurements. Immediately after the temperature jump from the melt to the crystallization point, the isolated domains consisting of the hydrogen-bonded random coils were formed in the melt, as revealed by Guinier plot of SAXS data and the infrared spectral data. With the passage of time these domains approached each other with stronger correlation as analyzed by Debye-Bueche equation. These domains transformed finally to the stacked crystalline lamellae, in which the conformationally- regularized methylene segments of the CO sides were connected each other by stronger intermolecular hydrogen bonds to form the crystal lattice. © 2009 IOP Publishing Ltd.

  300. Combinatory usage of X-ray and neutron diffraction techniques for the refined structure analysis of polymer crystals: From hydrogen atoms to bonded electron density distribution

    Kohji Tashiro, Makoto Hanesaka, Yoshinori Yoshizawa, Takashi Ohhara, Ryota Kuroki, Toshiaki Kitano, Takashi Nishu, Sono Sasaki, Masaki Takata

    Journal of Physics: Conference Series 184 2009年

    DOI: 10.1088/1742-6596/184/1/012012  

    ISSN:1742-6588

    eISSN:1742-6596

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    In order to predict the physical property of polymers, we need to know the atomic coordinates including hydrogen atoms as accurately as possible. However, polymer samples give us limited number of broad X-ray reflections in general. In order to improve this problem, we have made many efforts to collect the X-ray diffraction data as accurate as possible. In this paper, we report the structure analysis including the extraction of hydrogen/deuterium atomic positions for the oriented polyoxymethylene by the combination of X-ray diffraction method with neutron diffraction method. In such a cases of polydiacetylene giant single crystal the bonded electron density distribution was evaluated along the skeletal chain by the so-called X-N method based on the wide-angle X-ray diffraction data and the wide-angle neutron diffraction data. © 2009 IOP Publishing Ltd.

  301. Molecular aggregation states of poly{2-(perfluorooctyl)ethyl acrylate} polymer brush thin film analyzed by grazing incidence X-ray diffraction

    H. Yamaguchi, K. Honda, M. Kobayashi, M. Morita, H. Masunaga, O. Sakata, S. Sasaki, M. Takata, A. Takahara

    Journal of Physics: Conference Series 184 2009年

    DOI: 10.1088/1742-6596/184/1/012009  

    ISSN:1742-6588

    eISSN:1742-6596

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    Fluoropolymer brush with crystalline side chains was prepared by surface-initiated atom transfer radical polymerization of 2-(perfluorooctyl) ethyl acrylate (FA-C8) from a flat silicon substrate. The crystallization and the molecular aggregation structures of polymer side chain at the outermost surface and internal region in the brush film were characterized by grazing incidence X-ray diffraction (GIXD) measurement using two different incident angles of X-ray. At the air interface of PFA-C 8 brush film, the rod-like Rf group was oriented perpendicular to the surface forming a hexagonal packing structure to reduce surface energy. In contrast, the oriented Rf groups parallel to the substrate coexisted at the internal region in the brush. This unique depth dependence of crystalline state of the fluoropolymer brush was observed by surface-sensitive GIXD measurement. © 2009 IOP Publishing Ltd.

  302. Electron density distribution of β-rhombohedral boron constructed from icosahedral cluster

    Shizuka Hosoi, Kenji Tanabe, Hongki Kim, Kazuhiro Kirihara, Kohei Soga, Kaoru Kimura, Kenichi Kato, Masaki Takata

    Journal of Physics: Conference Series 176 2009年

    DOI: 10.1088/1742-6596/176/1/012026  

    ISSN:1742-6588

    eISSN:1742-6596

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    Boron forms unusual structures and chemical bonds. Pure boron and many boron-rich borides have local icosahedra in their crystalline structures. The electron density distribution (EDD) in β-rhombohedral boron (β-B 105) is visualized by the maximum entropy method (MEM)/Rietveld analysis of powder X-ray diffraction (XRD) data in order to discuss the peculiarity of the chemical bonds. In α-rhombohedral boron (α-B 12) and its derivative crystals, peculiar covalent bonds, i.e., intracluster three-center bonds and intercluster bent bonds, have been observed. In β-B105, the intracluster three-center bonds are observed, but the intercluster bent bonds are not. The origin of the bent bond can be explained by the mismatch in the directions of the bond and the lattice vector. © 2009 IOP Publishing Ltd.

  303. Structural evolution process of isotactic polypropylene in the isothermal crystallization from the melt

    Kummetha Raghunatha Reddy, Kohji Tashiro, Takashi Sakurai, Noburu Yamaguchi, Makoto Hanesaka, Sono Sasaki, Hiroyasu Masunaga, Masaki Takata

    Journal of Physics: Conference Series 184 2009年

    DOI: 10.1088/1742-6596/184/1/012001  

    ISSN:1742-6588

    eISSN:1742-6596

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    The melt-isothermal crystallization behaviour has been investigated for isotactic polypropylene (iPP) by means of time-resolved simultaneous measurements of small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) using synchrotron radiation source in SPring-8. The time-resolved Fourier-transform infrared spectral (FTIR) measurements were also performed to clarify the formation process of helices. The SAXS data were analyzed on the basis of Guinier (isolated domains) and Debye-Bueche (correlated domains) theories and correlation function (stacked lamellae). The results were combined with the FTIR data, allowing us to draw the concrete structural evolution process including the formation of regular helices and their growth, the correlation of higher density domains consisting of these helices, and the increment of correlation between the neighbouring lamellae to build up the stacked lamellar structure of higher crystallinity. © 2009 IOP Publishing Ltd.

  304. Effect of reflected waves on the GISAXS analysis of as-grown capped Ge nanodots

    H. Okuda, K. Kuno, S. Ochiai, N. Usami, K. Nakajima, O. Sakata, S. Sasaki, M. Takata

    Journal of Physics: Conference Series 184 2009年

    DOI: 10.1088/1742-6596/184/1/012005  

    ISSN:1742-6588

    eISSN:1742-6596

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    Effect of layer structures on the GISAXS intensity analysis of Ge nanodots capped with Si layer has been examined by Born Approximation and Distorted Wave Born Approximation simulations. It is concluded that when the dots are small enough in the out-of-plane directions, most of the structural information are deduced by simple BA. The effect of refracted wave became important when the area of interest is close to the Yoneda line or the analysis deals with small difference in the intermediate q range. © 2009 IOP Publishing Ltd.

  305. Crystallization behavior of polyethylene on silicon wafers in solution casting processes traced by time-resolved measurements of synchrotron grazing-incidence small-angle and wide-angle X-ray scattering

    S. Sasaki, H. Masunaga, K. Itou, K. Tashiro, H. Okuda, A. Takahara, M. Takata

    Journal of Physics: Conference Series 184 2009年

    DOI: 10.1088/1742-6596/184/1/012015  

    ISSN:1742-6588

    eISSN:1742-6596

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    Crystallization behavior of polyethylene (PE) on silicon wafers in solution casting processes has been successfully traced by time-resolved grazing-incidence small-angle and wide-angle X-ray scattering (GISWAXS) measurements utilizing synchrotron radiation. A p-xylene solution of PE kept at ca. 343 K was dropped on a silicon wafer at ca. 298 K. While the p-xylene evaporated naturally from the dropped solution sample, PE chains crystallized to be a thin film. Raman spectral measurements were performed simultaneously with the GISWAXS measurements to evaluate quantitatively the p-xylene the dropped solution contained. Grazing-incidence wide-angle X-ray scattering (GIWAXS) patterns indicated nucleation and crystal growth in the dropped solution and the following as-cast film. GIWAXS and Raman spectral data revealed that crystallization of PE was enhanced after complete evaporation of the p-xylene from the dropped solution. The [110] and [200] directions of the orthorhombic PE crystal became relatively parallel to the wafer surface with time, which implied that the flat-on lamellae with respect to the wafer surface were mainly formed in the as-cast film. On the other hand, grazing-incidence small-angle X-ray scattering (GISAXS) patterns implied formation of isolated lamellae in the dropped solution. The lamellae and amorphous might alternatively be stacked in the preferred direction perpendicular to the wafer surface. The synchrotron GISWAXS experimental method could be applied for kinetic study on hierarchical structure of polymer thin films. © 2009 IOP Publishing Ltd.

  306. Influence of α-methyl group on molecular aggregation structure and surface physicochemical properties of fluoroalkyl side chain polymers

    K. Honda, H. Yamaguchi, O. Sakata, S. Sasaki, M. Takata, M. Morita, A. Takahara

    Journal of Physics: Conference Series 184 2009年

    DOI: 10.1088/1742-6596/184/1/012007  

    ISSN:1742-6588

    eISSN:1742-6596

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    Influence of α-methyl group on molecular aggregation states and surface physicochemical properties of poly(fluoroalkyl acrylate)s [PFA-C y, where y is fluoromethylene number in Rf group] and poly(fluoroalkykl methacrylate)s [PFMA-Cy] thin films were systematically investigated. Spin-coated PFA-Cy and PFMA-C y thin films were characterized by dynamic contact angle measurements and grazing-incidence wide-angle X-ray diffraction (GIWAXD) measurements. GIWAXD data revealed that fluoroalkyl side chains of PFA-Cy and PFMA-Cy with y≥8 formed regular structures in the surface region as well as bulk one. However, the degree of orientation and ordering of the Rf groups of PFMA-C8 thin films was low. Also, the receding contact angle (θr) of PFMA-C8 thin films was lower than that of PFA-C8 ones. By annealing treatment, the θr of PFMA-C8 was increased. These results suggest that the Rf groups of PFMA-C8 were disordered due to presence of the α-methyl group. The Rf groups became ordered to pack closely each other by annealing treatment, so that the water repellency was increased. © 2009 IOP Publishing Ltd.

  307. First detection of lamella-gyroid-cylinder phase transition of neat polyethylene-poly(ethylene oxide) diblock copolymers on the basis of synchrotron WAXD/SAXS and infrared/Raman spectral measurements

    Cao Weiyu, Kohji Tashiro, Makoto Hanesaka, Shinichi Takeda, Hiroyasu Masunaga, Sono Sasaki, Masaki Takata

    Journal of Physics: Conference Series 184 2009年

    DOI: 10.1088/1742-6596/184/1/012003  

    ISSN:1742-6588

    eISSN:1742-6596

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    The phase transition behaviour of polyethylene-b-poly(ethylene oxide) (PE-b-PEO) diblock copolymer with relatively short chain lengths has been studied on the basis of temperature dependent infrared and Raman spectral measurements and synchrotron WAXD/SAXS simultaneous measurements, from which the concrete structural changes were deduced successfully from the various levels of molecular chain conformation, chain packing mode and higher-order structure. The higher-order structure has been found to transform between lamella, perforated lamella, gyroid, cylinder and sphere structures. The inner structural changes occurring in the polyethylene and poly(ethylene oxide) parts have been related with these morphological changes. The morphological transition from lamella to gyroid occurs with keeping the crystalline state of polyethylene parts. This apparently curious transition can be interpreted reasonably by assuming the thermally-activated chain motion in the crystal lattice, which may play an important role as a trigger to induce the morphological change from lamella to gyroid. This idea was supported by the measurement of half-width of Raman anti-symmetric CH2 stretching band sensitive to the thermal mobility of alkyl chains. © 2009 IOP Publishing Ltd.

  308. Hindered rotation of methane molecules in the one-dimensional nanochannel of a porous coordination polymer

    Yoshiki Kubota, Masaki Takata, Ryo Kitaura, Ryotaro Matsuda, Tatsuo C. Kobayashi, Susumu Kitagawa

    Journal of Nanoscience and Nanotechnology 9 (1) 69-76 2009年1月

    DOI: 10.1166/jnn.2009.J085  

    ISSN:1533-4880

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    The crystal structure of a microporous coordination polymer with adsorbed methane gas was determined by in situ synchrotron powder diffraction of the gas adsorption and the MEM (maximum entropy method)/Rietveld method. Methane molecules were found to be adsorbed forming a one-dimensional array in the nanochannels of the polymer. The MEM charge density distribution of the adsorbed methane molecules indicated some protrusions which were not observed in that of a spherical atom of adsorbed argon. This was interpreted as a mixed distribution of two uniaxially rotating molecules with different pivotal axes. The methane molecules displayed hindered rotation depending on the shape of the nanopore surface. This result indicates the capability to control the molecular arrangement and orientation by the adsorption of gas molecules on the precisely designed nanopores of coordination polymers. Copyright © 2009 American Scientific Publishers All rights reserved.

  309. Correlated changes in meso- and nano-scale hierarchical structure of vinylidene fluoride-trifluoroethylene random copolymers investigated by simultaneous measurements of DSC and SAXS/WAXD utilizing synchrotron radiation

    H. Masunaga, S. Sasaki, M. Takata, M. Hanesaka, K. Tashiro

    Journal of Physics: Conference Series 184 2009年

    DOI: 10.1088/1742-6596/184/1/012014  

    ISSN:1742-6588

    eISSN:1742-6596

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    Hierarchical structural features of Vinylidene fluoride-trifluoroethylene (VDF-TrFE) copolymers during the phase transition have been successfully investigated in detail by in-situ simultaneous measurements of DSC and SAXS/WAXD utilizing synchrotron radiation. In a heating process at a constant rate of 1 °C/min, a broad endothermic peak was measured for a VDF-TrFE copolymer from ca. 75°C to ca. 135°C. On the other hand, WAXD data indicated that the phase transition from the crystal form II to the high-temperature (HT) phase began to occur at ca. 105°C. With an increase in temperature from ca. 75° C to ca. 105° C (temperature region A), lamellar staking distance (long period) and lamellar thickness evaluated in SAXS data analyses slightly increased though the crystallite size (the lateral dimension of the lamellae) was almost constant. The (110) reflections of the crystal form II gradually decreased in integrated intensity and scattering from the amorphous region increased instead, which implied that lamellae in crystal form II became partially disordered before the phase transition. © 2009 IOP Publishing Ltd.

  310. Performance of the micro-PIC gaseous area detector in small-angle X-ray scattering experiments

    Kaori Hattori, Kenichi Tsuchiya, Kazuki Ito, Yoko Okada, Kotaro Fujii, Hidetoshi Kubo, Kentaro Miuchi, Masaki Takata, Toru Tanimori, Hidehiro Uekusa

    Journal of Synchrotron Radiation 16 (2) 231-236 2009年

    DOI: 10.1107/S0909049508041071  

    ISSN:0909-0495

    eISSN:1600-5775

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    The application of a two-dimensional photon-counting detector based on a micro-pixel gas chamber (-PIC) to high-resolution small-angle X-ray scattering (SAXS), and its performance, are reported. The -PIC is a micro-pattern gaseous detector fabricated by printed circuit board technology. This article describes the performance of the -PIC in SAXS experiments at SPring-8. A dynamic range of >105 was obtained for X-ray scattering from a polystyrene sphere solution. A maximum counting rate of up to 5 MHz was observed with good linearity and without saturation. For a diffraction pattern of collagen, weak peaks were observed in the high-angle region in one accumulation of photons. © 2009 International Union of Crystallography Printed in Singapore - All rights reserved.

  311. X-ray diffractometry for the structure determination of a submicrometre single powder grain

    Nobuhiro Yasuda, Haruno Murayama, Yoshimitsu Fukuyama, Jungeun Kim, Shigeru Kimura, Koshiro Toriumi, Yoshihito Tanaka, Yutaka Moritomo, Yoshihiro Kuroiwa, Kenichi Kato, Hitoshi Tanaka, Masaki Takata

    Journal of Synchrotron Radiation 16 (3) 352-357 2009年

    DOI: 10.1107/S090904950900675X  

    ISSN:0909-0495

    eISSN:1600-5775

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    A high-precision diffractometer has been developed for the structure analysis of a submicrometre-scale single grain of a powder sample at the SPring-8 BL40XU undulator beamline. The key design concept is the combination of a stable focused synchrotron radiation beam and the precise axis control of the diffractometer, which allows accurate diffraction intensity data of a submicrometre-scale single powder grain to be measured. The phase zone plate was designed to create a high-flux focused synchrotron radiation beam. A low-eccentric goniometer and high-precision sample positioning stages were adopted to ensure the alignment of a micrometre-scale focused synchrotron radiation beam onto the submicrometre-scale single powder grain. In order to verify the diffractometer performance, the diffraction pattern data of several powder grains of BaTiO3, of dimensions ̃600 × 600 × 300 nm, were measured. By identifying the diffraction data set of one single powder grain, the crystal structure was successfully determined with a reliable factor of 5.24%. © 2009 International Union of Crystallography.

  312. The key role of accurate lattice parameters in revealing subtle structural differences - A case study in the system [Ln(phen/phen-d<inf>8</inf>) <inf>2</inf>(NO<inf>3</inf>)<inf>3</inf>]

    Franz Werner, Kentaro Tada, Ayumi Ishii, Masaki Takata, Miki Hasegawa

    CrystEngComm 11 (7) 1197-1200 2009年

    DOI: 10.1039/b904694c  

    ISSN:1466-8033

    eISSN:1466-8033

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    In the model system [Ln(phen/phen-d8)2(NO 3)3] (Ln = Eu3+, Tb3+) the assignment of a new modification, based on the unit cell volumes, demonstrates the superior angular accuracy of synchrotron powder diffraction and the value of the lattice parameters refined thereof. © 2009 The Royal Society of Chemistry.

  313. Comparison of crystal structures and the effects of Co substitution in a new member of the Fe-1111 superconductor family AeFeAsF (Ae = Ca and Sr): A possible candidate for a higher-T<inf>c</inf> superconductor

    Takatoshi Nomura, Yasunori Inoue, Satoru Matsuishi, Masahiro Hirano, Jung Eun Kim, Kenichi Kato, Masaki Takata, Hideo Hosono

    Superconductor Science and Technology 22 (5) 2009年

    DOI: 10.1088/0953-2048/22/5/055016  

    ISSN:0953-2048

    eISSN:1361-6668

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    We refined crystal structures of newly found members of the Fe-1111 superconductor family, CaFe1-xCoxAsF and SrFe 1-xCoxAsF (x = 0,0.06,0.12) by powder synchrotron x-ray diffraction analysis. The tetragonal to orthorhombic phase transitions were observed at ∼120K for unsubstituted CaFeAsF and at ∼180K for unsubstituted SrFeAsF, the transition temperatures agreeing with kinks observed in temperature-dependent resistivity curves. Although the transition temperature decreases, the structural phase transitions were observed below 100K in both samples of x = 0.06, and finally they were suppressed in the doping level of x = 0.12. The refined structures reveal that distortions of the FeAs4 tetrahedron from the regular tetrahedron are likely to originate from mismatches in atomic radii among the constituent elements. In this system, the enlarged FeAs4 tetrahedron resulting from the fact that the radius of Sr is larger than that of Ca, is flattened along a-b plane, whereas the smaller radius of Ca makes the tetrahedron closer to a regular one, their characteristic shapes are further enhanced by Co substitution. These results suggest that the CaFeAsF compound is a promising candidate for a higher- Tc superconductor. © 2009 IOP Publishing Ltd.

  314. Structural phase transitions and superconductivity in Fe <inf>1+δ</inf>Se<inf>0.57</inf>Te<inf>0.43</inf> at ambient and elevated pressures

    Nathalie C. Gresty, Yasuhiro Takabayashi, Alexey Y. Ganin, Martin T. McDonald, John B. Claridge, Duong Giap, Yoshikazu Mizuguchi, Yoshihiko Takano, Tomoko Kagayama, Yasuo Ohishi, Masaki Takata, Matthew J. Rosseinsky, Serena Margadonna, Kosmas Prassides

    Journal of the American Chemical Society 131 (46) 16944-16952 2009年

    DOI: 10.1021/ja907345x  

    ISSN:0002-7863

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    The ternary iron chalcogenide, Fe1.03Se0.57Te 0.43 is a member of the recently discovered family of Fe-based superconductors with an ambient pressure Tc of 13.9 K and a simple structure comprising layers of edge-sharing distorted Fe(Se/Te)4 tetrahedra separated by a van der Waals gap. Here we study the relationship between its structural and electronic responses to the application of pressure. Tc depends sensitively on applied pressure attaining a broad maximum of 23.3 K at ∼3 GPa. Further compression to 12 GPa leads to a metallic but nonsuperconducting ground state. High-resolution synchrotron X-ray diffraction shows that the superconducting phase is metrically orthorhombic at ambient pressure but pressurization to ∼3 GPa leads to a structural transformation to a more distorted structure with monoclinic symmetry. The exact coincidence of the crystal symmetry crossover pressure with that at which Tc is maximum reveals an intimate link between crystal and electronic structures of the iron chalcogenide superconductors. © 2009 American Chemical Society.

  315. Evolution process of regular structure in isothermal crystallization phenomena of crystalline polymers viewed from synchrotron small-and wide-angle x-ray scatterings and vibrational spectroscopy

    Kohji Tashiro, Kummetha Raghunatha Reddy, Asami Nishiyama, Makoto Hanesaka, Sawako Tsuji, Tomoko Hashida, Cao Weiyu, Hiroyasu Masunaga, Sono Sasaki, Masaki Takata

    Kobunshi Ronbunshu 66 (12) 536-549 2009年

    DOI: 10.1295/koron.66.536  

    ISSN:0386-2186

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    The evolution processes of regular structure in isothermal crystallization phenomena of crystalline polymers have been investigated from the viewpoints of molecular level, crystal lattice, and higher-order structure on the basis of time- dependent infrared spectral data and synchrotron small- (SAXS) and wide-angle X-ray scattering (WAXD) data. The polymers treated here were isotactic polypropylene (iPP), nylon 10/10 and polyoxymethylene (POM). In the case of iPP, the formation and growing processes of regular helical segments in the molten state are described by utilizing the concept of critical sequential length for infrared bands. Combination of these spectroscopic data with the SAXS and WAXD data clarifies the formation process of domains consisting of regular helical segments, the increment of correlation of neighboring domains, and the development of stacked lamellar structure, during which the remarkable growth of crystal lattices consisting of regular helices occurs in parallel. In the case of nylon 10/10, weak hydrogen bonds are formed between amide groups even in the molten state. Once the isothermal crystallization starts to occur, these more-or-less correlated domains built up by the hydrogen bonds are formed followed by the formation of crystal lattices consisting of relatively regular methylene segments. Such growth is quite different from the case of iPP crystallization. The study of POM is based on the observation of infrared bands intrinsic to the folded chain crystals (FCC) and extended chain crystals (ECC). From the time-resolved measurements of these infrared bands as well as the SAXS and WAXD in the isothermal crystallization process of POM, we clarified that the lamellar structure of FCC morphology is formed at first. Then some new lamellae are formed in between these original lamellae, resulting in the formation of ECC parts in which the regular helices pass through the several neighboring lamellae as taut tie chains. © 2009, The Society of Polymer Science, Japan.

  316. Crystallographic phase transition and high-T<inf>c</inf> superconductivity in LaFeAsO:F

    T. Nomura, S. W. Kim, Y. Kamihara, M. Hirano, P. V. Sushko, K. Kato, M. Takata, A. L. Shluger, H. Hosono

    Superconductor Science and Technology 21 (12) 2008年12月1日

    DOI: 10.1088/0953-2048/21/12/125028  

    ISSN:0953-2048

    eISSN:1361-6668

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    Undoped LaFeAsO, the parent compound of the newly found high-Tc superconductor, exhibits a sharp decrease in the temperature-dependent resistivity at ∼160K. The anomaly can be suppressed by F doping with simultaneous appearance of superconductivity appears correspondingly, suggesting a close association of the anomaly with the superconductivity. We examined the crystal structures, magnetic properties and conductivity of undoped (normal conductor) and 14at.% F-doped LaFeAsO (Tc = 20K) by synchrotron x-ray diffraction (XRD), DC magnetic measurements, and abinitio calculations demonstrated that the anomaly is associated with a phase transition from tetragonal (P4/nmm) to orthorhombic (Cmma) phases at ∼160K as well as an antiferromagnetic spin ordering transition at ∼140K. These transitions can be explained by spin configuration-dependent potential energy surfaces derived from the abinitio calculations. The suppression of the transitions is ascribed to interrelated effects of geometric and electronic structural changes due to doping by F- ions. © 2008 IOP Publishing Ltd.

  317. Charge density distribution of KMnF3 under high pressure

    S. Aoyagi, S. Toda, E. Nishibori, Y. Kuroiwa, Y. Ohishi, M. Takata, M. Sakata

    Physical Review B - Condensed Matter and Materials Physics 78 (22) 2008年12月1日

    DOI: 10.1103/PhysRevB.78.224102  

    ISSN:1098-0121

    eISSN:1550-235X

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    The charge density distributions of KMnF3 under high pressure (0.3, 1.0, 1.7, 2.7, 3.4, 4.0, 4.8, 5.7, and 6.3 GPa) were determined from the synchrotron-radiation powder-diffraction data by the maximum entropy method (MEM). The difference-MEM charge density, which represents deformations from the spherical atomic charge density for each atom, is changed by applying pressure. The excess electrons on the Mn-F bond suggesting a Mn3d-F2p orbital hybridization were found in the difference-MEM charge densities at 0.3 GPa. The excess electrons are localized near Mn nuclei by increasing pressure. Two types of Mn-F bonds were found in the high-pressure tetragonal phase. One is parallel and another is perpendicular to the rotation axis of the F6 octahedra (i.e., c axis). The number of electrons for K, F, and Mn atoms was estimated from the MEM charge densities. The valence statuses of K atom were +1.02e at 0.3 GPa and +0.20e at 6.3 GPa. The valence statuses of F atom were -0.96e at 0.3GPa and -0.60 and -0.77e at 6.3 GPa. On the other hand, the valence status of Mn atom was virtually unchanged with pressure. This fact suggests that the electron charge transfer from F to K atom occurs with increasing pressure. © 2008 The American Physical Society.

  318. Desorption-erasure of the spin state transition in prussian-blue type cyanide

    Yutaka Moritomo, Fumiya Nakada, Jungeun Kim, Masaki Takata

    Applied Physics Express 1 (11) 1113011-1113013 2008年11月

    DOI: 10.1143/APEX.1.111301  

    ISSN:1882-0778

    eISSN:1882-0786

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    Desorption/adsorption of guest molecules in a nano-porous material is one of the sensitive tools to control the nature of the host framework via the strong guest-host interaction. A Co-Fe cyanide film, Na0.20Co[Fe(CN) 6]0.71zH2O, shows a spin state transition from the high-spin (HS) phase [Co2+ (S = 3/2)-Fe3+ (S = 1 /2)] to the low-spin (LS) phase [Co3+ (S = O)-Fe2+ (S = 0)] at Tc = 220 K. Here, we found that the existence (Tc = 220-263 K) and nonexistence (Tc ≤ 0 K) of the phase transition reversibly switched by the site-selective desorption of the guest waters. Such a gigantic controllability of Tc is ascribed to subtle competition between the HS phase and the LS phase together with the cooperative nature of the transition. © 2008 The Japan Society of Applied Physics.

  319. Prominent electron transport property observed for triply fused metalloporphyrin dimer: Directed columnar liquid crystalline assembly by amphiphilic molecular design

    Tsuneaki Sakurai, Keyu Shi, Hiroshi Sato, Kentaro Tashiro, Atsuhiro Osuka, Akinori Saeki, Shu Seki, Seiichi Tagawa, Sono Sasaki, Hiroyasu Masunaga, Keiichi Osaka, Masaki Takata, Takuzo Aida

    Journal of the American Chemical Society 130 (42) 13812-13813 2008年10月22日

    DOI: 10.1021/ja8030714  

    ISSN:0002-7863

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    A triply fused copper porphyrin dimer, when site-specifically modified on its periphery with hydrophobic and hydrophilic wedges (1C12/TEG), self-assembles into a columnar liquid crystalline (LC) mesophase over a wide-temperature range from -17 to 99 °C but gives rise to an amorphous solid when modified with only hydrophobic (1C12/C12) or hydrophilic wedges (1TEG/TEG). A LC film of 1C12/TEG displays at 16 °C a top-class one-dimensional electron mobility (0.27 cm2/V·s), as evaluated from its maximum flash-photolysis time-resolved microwave conductivity. Copyright © 2008 American Chemical Society.

  320. Nanochannels of two distinct cross-sections in a porous Al-based coordination polymer

    Angiolina Comotti, Silvia Bracco, Piero Sozzani, Satoshi Horike, Ryotaro Matsuda, Jinxi Chen, Masaki Takata, Yoshiki Kubota, Susumu Kitagawa

    Journal of the American Chemical Society 130 (41) 13664-13672 2008年10月15日

    DOI: 10.1021/ja802589u  

    ISSN:0002-7863

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    A new aluminum naphthalenedicarboxylate Al(OH)(1,4-NDC)·2H 2O compound has been synthesized. The crystal structure exhibits a three-dimensional framework composed of infinite chains of corner-sharing octahedral Al(OH)2O4 with 1,4-naphthanedicarboxylate ligands forming two types of channels with squared-shape cross-section. The large channels present a cross-section of 7.7 × 7.7 Å2, while the small channels are about 3.0 × 3.0 Å2. When water molecules are removed, no structural transformation occurs, generating a robust structure with permanent porosity and remarkable thermal stability. 2D 1H-13C heteronuclear correlation NMR measurements, together with the application of Lee-Goldburg homonuclear decoupling, were applied, for the first time, to porous coordination polymers revealing the spatial relationships between the 1H and 13C spin-active nuclei of the framework. To demonstrate the open pore structure and the easy accessibility of the nanochannels to the gas phase, highly sensitive hyperpolarized (HP) xenon NMR, under extreme xenon dilution, has been applied. Xenon can diffuse selectively into the large nanochannels, while the small ones show no substantial uptake of xenon due to severe restrictions along the channels that prevent the diffusion. Two-dimensional exchange experiments showed the exchange time to be as short as 15 ms. Through variable-temperature HP 129Xe NMR experiments we were able to achieve an unprecedented description of the large nanochannel space and surface, a physisorption energy of 10 kJ mol-1, and the chemical shift value of xenon probing the internal surfaces. The large pore channels are straight, parallel, and independent, allowing one-dimensional anisotropic diffusion of gases and vapors. Their walls are composed of the naphthalene moieties that create an unique environment for selective sorption. These results prompted us to measure the storage capacity toward methanol, acetone, benzene, and carbon dioxide. The selective adsorption of methanol and acetone vs that of water, together with the permanent porosity and high thermal stability, makes this compound a suitable matrix for separation and purification. © 2008 American Chemical Society.

  321. Structural features of Ge<inf>1</inf>Sb<inf>4</inf>Te<inf>7</inf>, an intermetallic compound in the GeTe-Sb<inf>2</inf>Te<inf>3</inf> homologous series

    Toshiyuki Matsunaga, Rie Kojima, Noboru Yamada, Kouichi Kifune, Yoshiki Kubota, Masaki Takata

    Chemistry of Materials 20 (18) 5750-5755 2008年9月23日

    DOI: 10.1021/cm703484k  

    ISSN:0897-4756

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    The structural and bonding nature of Ge1Sb4Te 7 is investigated using an X-ray diffraction method and calculations based on density-functional theory (DFT). This material's crystal is confirmed to have a 12-layered, close-packed cubic stacking structure (P3̄m1). In this crystal, Te atoms occupy their own specific layers; however, it has been revealed that Ge and Sb atoms are not located in their respective layers but cause partial atomic disordering across other layers. The structure consists of two kinds of NaCl slabs stacked alternately, and the calculations demonstrate that adjacent slabs are connected by a van der Waals-type weak force and that Ge1Sb4Te7 forms a compound semiconductor with a very narrow band gap. © 2008 American Chemical Society.

  322. Electron charge density study of (Na<inf>1-x</inf>K<inf>x</inf>)NbO <inf>3</inf> in cubic structure

    Chikako Moriyoshi, Jun Ichi Kato, Yoshihiro Terado, Satoshi Wada, Masaki Takata, Yoshihiro Kuroiwa

    Japanese Journal of Applied Physics 47 (9 PART 2) 7745-7748 2008年9月19日

    DOI: 10.1143/JJAP.47.7745  

    ISSN:0021-4922

    eISSN:1347-4065

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    The electron charge density study by synchrotron-radiation powder diffraction has been performed for the cubic structure of (Na 1-xKx)NbO3 (NKN: 0 ≤ x ≤ 1) at 1000 K to investigate the atomic substitution effect on chemical bonding. Our precise analysis using the maximum entropy method (MEM)/Rietveld method demonstrates that the covalent bonding is formed on the Nb-O bond whereas the Na/K atoms are ionic in the entire composition range. The thermal motion of the Na ion in NaNbO3 is fairly larger than that of the K ion in KNbO3. The charge density distributions around the O atoms in NaNbO3 are extended in the directions perpendicular to the Nb-O bond, which can be related to the rotational mode of the Nb-O6 octahedron driving the antiferroic phase transition. No such anisotropy is clearly observed in KNbO3 around the O atoms. These behaviors are closely related to the change in the tolerance of the perovskite structure caused by the atomic substitution. ©2008 The Japan Society of Applied Physics.

  323. Charge-density-wave to Mott-Hubbard phase transition in quasi-one-dimensional bromo-bridged Pd compounds

    Shinya Takaishi, Mitsuhito Takamura, Takashi Kajiwara, Hitoshi Miyasaka, Masahiro Yamashita, Muneaki Iwata, Hiroyuki Matsuzaki, Hiroshi Okamoto, Hisaaki Tanaka, Shin Ichi Kuroda, Hiroyuki Nishikawa, Hiroki Oshio, Kenichi Kato, Masaki Takata

    Journal of the American Chemical Society 130 (36) 12080-12084 2008年9月10日

    DOI: 10.1021/ja8032026  

    ISSN:0002-7863

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    A -PdIIIBr-PdIII- Mott-Hubbard state was observed in a quasi-one-dimensional bromo-bridged Pd compound [Pd(Bn)2Br](C 5-Y)2·H2O (en = ethylenediamine, C 5-Y = dipentylsulfosuccinate) for the first time. The phase transition between Mott-Hubbard and charge-density-wave states occurred at 206 ± 2 K and was confirmed by using X-ray, ESR, Raman and electronic spectroscopies, electrical resistivity, and heat capacity. From X-ray powder diffraction patterns and Raman spectra of a series of Pd-Br compounds, [Pd(en)2Br](Cn-Y)2·H2O (n = 4, 5, 6, 7, 8, 9, and 12), chemical pressure from the alkyl chains of the counterions caused the phase transition. © 2008 American Chemical Society.

  324. Highly intense monochromatic X-ray diffraction facility for high-pressure research at SPring-8

    Yasuo Ohishi, Naohisa Hirao, Nagayoshi Sata, Kei Hirose, Masaki Takata

    High Pressure Research 28 (3) 163-173 2008年9月

    DOI: 10.1080/08957950802208910  

    ISSN:0895-7959

    eISSN:1477-2299

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    Beamline BL10XU at SPring-8, designed for X-ray diffraction experiments using diamond anvil cells at high pressure and low/high temperature, is continuously upgraded. The X-ray source, optics, and attractive experimental equipment such as simultaneous measurement systems have been optimized over the past years. The high energy and high intensity monochromatic X-ray beams emitted by an undulator source, focused using a characteristic X-ray refractive lens, have enabled us to obtain excellent counting statistics and high-resolution X-ray diffraction data even from a highly compressed sample under multi-megabar pressure. At BL10XU, low- and high-temperature conditions are achieved using a cryostat (10-300 K) and double-sided laser-heating system (1000-4000 K), respectively. Numerous results have been obtained in the fields of high-pressure materials science and mineral physics: for instance, the structural information on novel materials under pressure, including new pressure-induced structural phase transitions, the measurements of equations of states, and the phase-equilibrium data of Earth interior minerals.

  325. Orientational correlations in high-pressure fluid oxygen and nitrogen

    L. Temleitner, L. Pusztai, Y. Akahama, H. Kawamura, S. Kohara, Y. Ohishi, M. Takata

    Physical Review B - Condensed Matter and Materials Physics 78 (1) 2008年7月29日

    DOI: 10.1103/PhysRevB.78.014205  

    ISSN:1098-0121

    eISSN:1550-235X

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    High-pressure x-ray diffraction measurements for supercritical fluid oxygen at 0.9, 1.2, 4.3, and 5.2 GPa and for supercritical fluid nitrogen at 2.5 GPa have been carried out at room temperature by using synchrotron x-ray diffraction. The structure factors have been interpreted by means of the reverse Monte Carlo method. Site-site and center-center radial distribution functions and relative orientations of molecular axes as a function of distance between molecular centers have been calculated from the particle configurations. At distances below the position of the first maximum of the center-center radial distribution function, the dominance of parallel and "X-shaped" alignments of neighboring molecules has been revealed. Superfluid O2 was found to display considerably stronger orientational correlations than N2. Structural differences between oxygen at 4.3 and 1.2 GPa can be explained by the different densities of these systems. © 2008 The American Physical Society.

  326. Argon adsorption on MCM-41 mesoporous crystal studied by in situ synchrotron powder X-ray diffraction

    Norihiro Muroyama, Arisa Yoshimura, Yoshiki Kubota, Keiichi Miyasaka, Tetsu Ohsuna, Ryong Ryoo, Peter I. Ravikovitch, Alexander V. Neimark, Masaki Takata, Osamu Terasaki

    Journal of Physical Chemistry C 112 (29) 10803-10813 2008年7月24日

    DOI: 10.1021/jp800385t  

    ISSN:1932-7447

    eISSN:1932-7455

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    Equilibrium argon adsorption from the gas phase on mesoporous MCM-41 silica of hexagonal structure is directly studied by in situ synchrotron powder X-ray diffraction (XRD) measurements at SPring-8. The diffraction intensity data is analyzed by extending the previously developed analytical formula for the crystal structure factors of MCM-41 to account for argon adsorbed in the pores. It is clearly observed that argon adsorbs in layers on the pore walls at low gas pressures and exhibits sudden capillary condensation as the gas pressure increased. The proposed method of interpretation of XRD data allows one to calculate the density ratio between the silica wall and condensed argon, the pore size, and the pore wall fluctuation/roughness, together with the thickness of the adsorbed layer as a function of the gas pressure. The results of in situ XRD experiments are compared with the results of argon adsorption volumetric experiments. The adsorption data are interpreted with the quench solid density functional theory (QSDFT), which takes into account the pore wall roughness. The perfect agreement of the QSDFT isotherm predicted from the adsorption data and the XRD recalculated isotherm suggests that the adsorption porosimetry and XRD measurements can be reconciled provided a proper interpretation of the experimental data. © 2008 American Chemical Society.

  327. Systematic studies on structural parameters for nanotubular assembly of hexa-peri-hexabenzocoronenes

    Wusong Jin, Yohei Yamamoto, Takanori Fukushima, Noriyuki Ishii, Jungeun Kim, Kenichi Kato, Masaki Takata, Takuzo Aida

    Journal of the American Chemical Society 130 (29) 9434-9440 2008年7月23日

    DOI: 10.1021/ja801179e  

    ISSN:0002-7863

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    Thirteen different hexa-peri-hexabenzocoronenes (HBCs) I-III were newly synthesized, and their self-assembling behaviors were investigated. Taking into account also the reported behaviors of amphiphilic HBCs, some structural parameters of HBC essential for the tubular assembly were revealed. Points to highlight include (1) the importance of two phenyl groups attached to one side of the HBC unit, (2) essential roles of long paraffinic side chains on the other side of the phenyl groups, and (3) no necessity of hydrophilic oligo(ethylene glycol) side chains. The hierarchical nanotubular structure, rendered by virtue of a synchrotron radiation technique, was virtually identical to our previous proposal, where the nanotubes are composed of helically coiled bilayer tapes with a tilting angle of ∼45°. Each tape consists of π-stacked HBC units, where the inner and outer HBC layers are connected by interdigitation of paraffinic side chains. The coiled structure is most likely caused by a steric congestion of the phenyl groups attached to the HBC unit, whose tilting direction may determine the handedness of the helically chiral nanotube. © 2008 American Chemical Society.

  328. Amphiphilic molecular design as a rational strategy for tailoring bicontinuous electron donor and acceptor arrays: Photoconductive liquid crystalline oligothiophene-C<inf>60</inf> dyads

    Wei Shi Li, Yohei Yamamoto, Takanori Fukushima, Akinori Saeki, Shu Seki, Seiichi Tagawa, Hiroyasu Masunaga, Sono Sasaki, Masaki Takata, Takuzo Aida

    Journal of the American Chemical Society 130 (28) 8886-8887 2008年7月16日

    DOI: 10.1021/ja802757w  

    ISSN:0002-7863

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    For tailoring solution-processable optoelectronic thin films, a rational strategy with amphiphilic molecular design is proposed. A donor-acceptor dyad consisting of an oligothiophene and C60, when modified with a hydrophilic wedge on one side and a paraffinic wedge on the other (1Amphi), forms over a wide temperature range a photoconducting smectic A liquid crystal having bicontinuous arrays of densely packed donor and acceptor units. In contrast, when modified with only paraffinic wedges (1Lipo), the dyad forms a smectic A liquid crystalline mesophase, which however is poorly conductive. As indicated by an absorption spectral feature along with a synchrotron radiation small-angle X-ray scattering profile, 1Lipo in the lamellar structure does not adopt a uniform head/tail orientation. Such defective donor and acceptor arrays likely contain a large number of trapping sites, leading to short-lived charge carriers, as observed by a flash photolysis time-resolved microwave conductivity study. Copyright © 2008 American Chemical Society.

  329. Electronic phase diagram of valence-controlled cyanide: Na0.84-δ Co [Fe (CN) 6] 0.71 3.8 H2 O (0≤δ≤0.61)

    F. Nakada, H. Kamioka, Y. Moritomo, J. E. Kim, M. Takata

    Physical Review B - Condensed Matter and Materials Physics 77 (22) 2008年6月23日

    DOI: 10.1103/PhysRevB.77.224436  

    ISSN:1098-0121

    eISSN:1550-235X

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    Electronic phase diagram has been derived for the Prussian-Blue-type cyano-bridged transition-metal compound, Na0.84-δ Co [Fe (CN) 6] 0.71 3.8 H2 O (0.0≤δ≤0.61), as a function of the hole concentration δ of the d -electron system. The mother compound (δ=0) takes the Co2+ (t 2g 5 eg2: S=3/2) and Fe2+ (t 2g 6: S=0) configuration and is paramagnetic down to zero temperature. At room temperature, the holes are selectively introduced on the Fe site. A slight hole doping (δ=0.13) causes the charge-transfer (CT) transition, that is, cooperative electron transfer from the Co2+ site to the Fe3+ site, with a decrease in temperature below TCT ≈250 K. With a further increase in δ, TCT slightly decreases from ≈230 K at δ=0.24 to ∼210 K at δ=0.61. Accordingly, the nature of the transition changes from the second-order type to the first-order type. In all the concentration ranges, the high-temperature (HT) phase is metastable even at low temperature. In this metastable phase, the Fe3+ (t 2g 5: S=1/2) species mediate the ferromagnetic exchange coupling between the adjacent Co2+ spins. The ferromagnetic transition appears at δ=0.39, and the transition temperature TC increase from 7 K at δ=0.39 to 13 K at δ=0.61. Based on these experimental data, we will discuss the significant roles of the coupling between the charge, spin, and lattice degrees of freedom in the transition-metal cyanides. © 2008 The American Physical Society.

  330. Kinetic gate-opening process in a flexible porous coordination polymer

    Daisuke Tanaka, Keiji Nakagawa, Masakazu Higuchi, Satoshi Horike, Yoshiki Kubota, Tatsuo C. Kobayashi, Masaki Takata, Susumu Kitagawa

    Angewandte Chemie - International Edition 47 (21) 3914-3918 2008年5月13日

    DOI: 10.1002/anie.200705822  

    ISSN:1433-7851

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    (Graph Presented) Open the gate! A porous coordination polymer shows abrupt changes in its adsorption isotherm with guest-dependent gate-opening pressure (see picture). Kinetic analysis reveals that adsorption with structure transformation follows a gate-opening model, in which adsorption proceeds through the formation of an intermediate by a gate-opening process. This process provides a significant difference in onset pressure between similar gas molecules. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.

  331. Structural and magnetic properties of spinel FeV<inf>2</inf>O<inf>4</inf> with two ions having orbital degrees of freedom

    Takuro Katsufuji, Takehito Suzuki, Haruki Takei, Masao Shingu, Kenichi Kato, Keiichi Osaka, Masaki Takata, Hajime Sagayama, Taka Hisa Arima

    Journal of the Physical Society of Japan 77 (5) 2008年5月

    DOI: 10.1143/JPSJ.77.053708  

    ISSN:0031-9015

    eISSN:1347-4073

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    Spinel FeV2O4 with orbital degrees of freedom both at the Fe2+ and V3+ ions exhibits successive structural phase transitions. We studied this structural and magnetic properties as well as the correlation between the two. We found that the crystalline domains in the tetragonal or orthorhombic phases can be aligned by the applied magnetic field, inducing a large magnetostriction (∼1%). The competition and cooperation of Fe2+ and V3+ orbitals is the possible origin of these intriguing properties in FeV2O4. ©2008 The Physical Society of Japan.

  332. Time-resolved investigation of nanosecond crystal growth in rapid-phase-change materials: Correlation with the recording speed of digital versatile disc media

    Yoshimitsu Fukuyama, Nobuhiro Yasuda, Jungeun Kim, Haruno Murayama, Yoshihito Tanaka, Shigeru Kimura, Kenichi Kato, Shinji Kohara, Yutaka Moritomo, Toshiyuki Matsunaga, Rie Kojima, Noboru Yamada, Hitoshi Tanaka, Takashi Ohshima, Masaki Takata

    Applied Physics Express 1 (4) 0450011-0450013 2008年4月

    DOI: 10.1143/APEX.1.045001  

    ISSN:1882-0778

    eISSN:1882-0786

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    The crystallization process in digital versatile disc (DVD) media was investigated using a time-resolved X-ray diffraction apparatus coupled with in situ photoreflectivity measurement. The time profiles of crystallization were found to be consistent with the changes in photoreflectivity. The phase changes were characterized by the start and end time; 90 ±1 and 273 ± 1 ns for Ge2Sb2Te5, and 85 ± 1 and 206 ± 1 ns for Ag3.5In3.5Sb75.0Te 17.7, respectively. The faster crystallization time in Ag 3.5In3.8Sb75.0Te17.7 is ascribed to its characteristic crystallization process; its X-ray diffraction profile shows a significant sharpening during the crystallization process, whereas the peak width of Ge2Sb2Te5 remained unchanged. The present findings suggest that crystal growth control is another key for designing faster phasechange materials. © 2008 The Japan Society of Applied Physics.

  333. Nanosize effects on hydrogen storage in palladium

    Miho Yamauchi, Ryuichi Ikeda, Hiroshi Kitagawa, Masaki Takata

    Journal of Physical Chemistry C 112 (9) 3294-3299 2008年3月6日

    DOI: 10.1021/jp710447j  

    ISSN:1932-7447

    eISSN:1932-7455

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    The size dependencies of the hydrogen-storage properties in polymer-coated Pd nanoparticles with diameters of 2.6 ± 0.4 and 7.0 ± 0.9 nm were investigated by a measurement of hydrogen pressure-composition isotherms. Their storage capacities per constituent Pd atom in the particles decreased with decreasing particle size, whereas the hydrogen concentrations in the two kinds of nanoparticles were almost the same and 1.2 times as much, respectively, as that in bulk palladium after counting zero hydrogen occupancy on the atoms in the first surface layer of the particles. Furthermore, apparent changes in hydrogen absorption behavior with decreasing particle size were observed, that is, a narrowing of the two-phase regions of solid-solution and hydride phases, the lowering of the equilibrium hydrogen pressure, and a decrease in the critical temperature of the two-phase state. By analyzing the isotherms, we quantitatively determined the heat of formation (ΔH α-β) and the entropy change (ΔS α-β) in the hydride formation of the nanoparticle. ΔHα-β and ΔSα-β for the 2.6 ± 0.4 nm diameter Pd nanoparticle were -34.6 ± 0.61 kJ(H 2 mol)-1 and -83.1 ± 1.8 J(H2 mol) -1K-1, whereas for the 7.0 ± 0.9 nm diameter Pd nanoparticles the values were -31.0 ± 1.8 kJ(H2 mol) -1 and -67.3 ± 5.1 J(H2 mol)-1K -1, respectively. These quantities gave us a prospective picture of hydrogen absorption in Pd nanoparticles and the peculiarities in the formation of a single nanometer-sized hydride. © 2008 American Chemical Society.

  334. Visualization of charge ordering in a half-doped manganite by an electrostatic potential analysis

    K. Kato, Y. Moritomo, M. Takata, H. Tanaka, N. Hamada

    Physical Review B - Condensed Matter and Materials Physics 77 (8) 2008年2月28日

    DOI: 10.1103/PhysRevB.77.081101  

    ISSN:1098-0121

    eISSN:1550-235X

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    We have experimentally investigated the charge density distribution and the electrostatic potential for a charge-ordering doped manganite, Nd1/2 Sr1/2 MnO3. In the charge-ordered state, we observed a zigzag pattern of the charge density within the (010) plane. Judging from the MnO6 distortion, we ascribed the pattern to the bonding electron in the px(y) - d x2 - y2 hybridized state, not to the so-called d3 x2 - r2/d3 y2 - r2 orbital ordering. We further calculated the electrostatic potential U(r) from the charge density and the atomic positions, which clearly indicates the checkerboard-type charge disproportionation within the (010) plane. © 2008 The American Physical Society.

  335. Pressure-induced unconventional superconductivity in the heavy-fermion antiferromagnet CeIn3: An In115 -NQR study under pressure

    S. Kawasaki, M. Yashima, Y. Kitaoka, K. Takeda, K. Shimizu, Y. Oishi, M. Takata, T. C. Kobayashi, H. Harima, S. Araki, H. Shishido, R. Settai, Y. Onuki

    Physical Review B - Condensed Matter and Materials Physics 77 (6) 2008年2月14日

    DOI: 10.1103/PhysRevB.77.064508  

    ISSN:1098-0121

    eISSN:1550-235X

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    We report on pressure-induced unconventional superconductivity (SC) in the heavy-fermion (HF) antiferromagnet CeIn3 by means of nuclear-quadrupole- resonance (NQR) studies conducted under a high pressure. The temperature (T) and pressure (P) dependences of the In-NQR spectra have revealed a first-order quantum-phase transition (QPT) from antiferromagnetism (AFM) to paramagnetism (PM) at a critical pressure Pc =2.46 GPa at which AFM disappears with a minimum value of TN (Pc) =1.2 K. High-energy x-ray scattering measurements under P show a progressive decrease in the lattice density without any change in the crystal structure, whereas an increase in the NQR frequency (νQ) indicates an increase in the hybridization between 4f electrons and conduction electrons, which stabilizes the HF-PM state. This competition between the AFM phase where TN is reduced and the formation of the HF-PM phase triggers the first-order QPT at Pc =2.46 GPa. Despite the lack of an AFM quantum critical point in the P-T phase diagram, we highlight the fact that unconventional SC occurs in both phases of AFM and PM. The measurements of the nuclear spin-lattice relaxation rate 1/T1 in the AFM phase have provided evidence for the uniformly coexisting AFM+SC phase. Remarkably, the significant increase in 1/T1 upon cooling in the AFM phase has revealed the development of low-lying magnetic excitations down to Tc in the AFM phase; it is indeed relevant to the onset of the uniformly coexisting AFM+SC phase. In the HF-PM phase where AFM fluctuations are not developed, 1/T1 decreases without the coherence peak just below Tc, followed by a power-law-like T dependence that indicates an unconventional SC with a line-node gap. Remarkably, Tc has a peak around Pc in the HF-PM phase as well as in the AFM phase. In other words, an SC dome exists with a maximum value of Tc =230 mK around Pc, indicating that the origin of the pressure-induced HF SC in CeIn3 is not relevant to AFM spin fluctuations but to the emergence of the first-order QPT in CeIn3. These phenomena observed in CeIn3 should be understood in terms of the first-order QPT because these new phases of matter are induced by applying P. When the AFM critical temperature is suppressed at the termination point of the first-order QPT, Pc =2.46 GPa, the diverging AFM spin-density fluctuations emerge at the critical point from AFM to PM. The results with CeIn3 leading to a new type of quantum criticality deserve further theoretical investigations. © 2008 The American Physical Society.

  336. Hydrogen absorption in the core/shell interface of Pd/Pt nanoparticles

    Hirokazu Kobayashi, Miho Yamauchi, Hiroshi Kitagawa, Yoshiki Kubota, Kenichi Kato, Masaki Takata

    Journal of the American Chemical Society 130 (6) 1818-1819 2008年2月13日

    DOI: 10.1021/ja078126k  

    ISSN:0002-7863

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    We have investigated the hydrogen absorption behavior of Pd/Pt nanoparticles with a core/shell-type structure. From the results of the hydrogen pressure-composition (PC) isotherm and solid-state 2H NMR measurements, it was revealed that the Pd/Pt nanoparticles can absorb hydrogen, and most of the absorbed hydrogen atoms are situated around the interfacial region between the Pd core and the Pt shell of the Pd/Pt nanoparticles, indicating that the core/shell boundary plays an important role in the formation of the hydride phase of the Pd/Pt nanoparticles. Copyright © 2008 American Chemical Society.

  337. On the nature of strong hydrogen atom trapping inside Pd nanoparticles

    Hirokazu Kobayashi, Miho Yamauchi, Hiroshi Kitagawa, Yoshiki Kubota, Kenichi Kato, Masaki Takata

    Journal of the American Chemical Society 130 (6) 1828-1829 2008年2月13日

    DOI: 10.1021/ja7102372  

    ISSN:0002-7863

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    We have investigated the hydrogen absorption/desorption hysteresis by means of in situ powder X-ray diffraction (XRD) and solid-state 2H NMR to clarify the location of hydrogen, surface or body, and its chemical form, molecular, atomic, or as hydride. The present results point out that strongly trapped hydrogen atoms exist inside the Pd nanoparticles due to a strong Pd-H bond formation and are stabilized in the lattice of Pd nanoparticles, compared to bulk Pd. Copyright © 2008 American Chemical Society.

  338. Conducting dimerized cobalt complexes with tetrathiafulvalene dithiolate ligands

    Emiko Fujiwara, Kazumasa Hosoya, Akiko Kobayashi, Hisashi Tanaka, Madoka Tokumoto, Yoshinori Okano, Hideki Fujiwara, Hayao Kobayashi, Yuichi Fujishiro, Eiji Nishibori, Masaki Takata, Makoto Sakata

    Inorganic Chemistry 47 (3) 863-874 2008年2月4日

    DOI: 10.1021/ic701100r  

    ISSN:0020-1669

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    To obtain novel single-component molecular metals, we attempted to synthesize several cobalt complexes coordinated by TTF (tetrathiafulvalene)-type dithiolate ligands. We succeeded in the syntheses and structure determinations of (nBu4N)2[Co(chdt)2]2 (1), (nBu4N)2[Co(dmdt)2]2 (2), [Co(dmdt)2]2 (3), and [Co(dt)2] 2 (4) (chdt = cyclohexeno-TTF-dithiolate, dmdt = dimethyl-TTF- dithiolate, and dt = TTF-dithiolate). Structure analyses of complexes 1-4 revealed that two monomeric [Co(ligand)2]- or [Co(ligand)2]0 units are connected by two Co-S bonds resulting in dimeric [Co(ligand)2]22- or [Co(ligand)2]2 molecules. Complex 1 has a cation-anion-intermingled structure and exhibited Curie-Weiss magnetic behavior with a large Curie constant (C - 2.02 K·emu·mol-1) and weak antiferromagnetic interactions (θ = -8.3 K). Complex 2 also has a cation-anion-intermingled structure. However, the dimeric molecules are completely isolated by cations. Complexes 3 and 4 are single-component molecular crystals. The molecules of complex 3 form two-dimensional molecular stacking layers and exhibit a room-temperature conductivity of σrt = 1.2 × 10-2 S·cm-1 and an activation energy of Ea = 85 meV. The magnetic behavior is almost consistent with Curie-Weiss law, where the Curie constant and Weiss temperature are 8.7 × 10-2 K·emu·mol-1 and -0.85 K, respectively. Complex 4 has a rare chair form of the dimeric structure. The electrical conductivity was fairly large (σrt = 19 S·cm -1), and its temperature dependence was very small (σ0.55K/σrt = ca. 1:10), although the measurements were performed on the compressed pellet sample. Complex 4 showed an almost constant paramagnetic susceptibility (χ300 K = 3.5 × 10-4 emu·mol-1) from 300 to 50 K. The band structure calculation of complex 4 suggested the metallic nature of the system. Complex 4 is a novel single-component molecular conductor with a dimeric molecular structure and essentially metallic properties down to very low temperatures. © 2008 American Chemical Society.

  339. Pressure-temperature phase diagram for charge-transfer transition in Cs [Co (3-CNpy)2] [W (CN)8] H2 O

    J. E. Kim, Y. Ohishi, Y. Moritomo, K. Kato, M. Takata, S. Ohkoshi

    Physical Review B - Condensed Matter and Materials Physics 77 (1) 2008年1月22日

    DOI: 10.1103/PhysRevB.77.012101  

    ISSN:1098-0121

    eISSN:1550-235X

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    Effects of the hydrostatic pressure on the magnetic and structural properties are investigated in a charge-transfer material, Cs [Co (3-CNpy)2] [W (CN)8] H2 O (CNpy=cyanopyridine), with two-dimensional Co-W network bridged by CN anions. We have found that the compound shows a pressure-induced charge-transfer (CT) transition at 0.5 GPa at room temperature, accompanied by a remarkable color change from transparent red to green. The upper critical temperature (TCT,up) for the CT transition increases at a huge rate of 250 KGPa under pressures, reflecting the concomitant significant volume change (ΔVV=0.08). © 2008 The American Physical Society.

  340. Structural analysis of the rare earth metal hydride complexes

    Nobuhiro Mizuno, Shima Takanori, Tanaka Hiroshi, Hou Zhaomin, Takata Masaki

    ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 64 C405-C405 2008年

    出版者・発行元:INT UNION CRYSTALLOGRAPHY

    DOI: 10.1107/S0108767308087023  

    ISSN:2053-2733

  341. Tetragonal-orthorhombic phase transition and F-doping effects on the crystal structure in the iron-based high-T<inf>c</inf> superconductor LaFeAsO

    Takatoshi Nomura, Sung Wng Kim, Yoichi Kamihara, Masahiro Hirano, Peter V. Sushko, Kenichi Kato, Masaki Takata, Alexander L. Shluger, Hideo Hosono

    Journal of the Physical Society of Japan 77 (SUPPL. C) 32-35 2008年

    DOI: 10.1143/JPSJS.77SC.32  

    ISSN:0031-9015

    eISSN:1347-4073

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    Crystal structure refinements of undoped and 14 atomic% F-doped LaFeAsO (Tc = 20 K) were performed over the temperature region of 25 K to 300 K by synchrotron X-ray diffraction. The electronic structures of the crystals were also examined using density functional theory (DFT). Undoped LaFeAsO was observed to undergo a crystallographic transition from the tetragonal (P4/nmm) to orthorhombic (Cmma) phases at ∼160 K. This crystallographic transition was accompanied with an antiferromagnetic spin ordering at ∼140 K. The DFT calculation results suggest that both transitions were caused by the "Cooperative Jahn-Teller effect". In contrast, an F-doped sample maintains the non-magnetic tetragonal phase down to 25 K. F-ion substitutions for the O sites changed the bond length and angle in the distorted LaO tetrahedron, whereas weaker geometric effects were observed in the FeAs layer. Further, the F-doping induced large decreases in the c-axis length and the La-As distance, suggesting an enhancement of the charge polarizations in the (LaO)δ+ and (FeAs)δ- layers as a result of electron transfer between two layers. The enhanced polarization and Fe-Fe interaction in the FeAs layer are likely to suppress the transitions leading to the emergence of a superconducting phase. ©2008 The Physical Society of Japan.

  342. Solidification of bulk metallic glass-forming alloys observed by time-resolved X-ray diffraction combined with levitation technique

    Toshihiko Akimoto, Akitoshi Mizuno, Masahito Watanabe, Yoshihiko Yokoyama, Shinji Kohara, Masayoshi Ito, Masaki Takata

    Materials Research Society Symposium Proceedings 1152 62-66 2008年

    DOI: 10.1557/proc-1152-tt01-04  

    ISSN:0272-9172

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    It is well known that multi-component alloys form bulk metallic glasses (BMGs) from the supercooled liquid state without rapid quenching. However, the mechanism of phase selection between crystal and glass states has not been fully clarified. To obtain an insight into the glass-forming processes, we carried out in-situ observation on the solidification of Zr-based BMG-forming alloys from its supercooled liquids by time-resolved X-ray diffraction combined with the conical nozzle levitation (CNL) technique to achieve a containerless melting. For Zr50Cu40Al10 alloys, we succeeded in detecting the X-ray diffraction patterns during glass formation from the supercooled liquid state as well as the crystallization from the liquid state. Furthermore we performed the precise structure analysis of supercooled state of Zr-based binary liquids. Based on the liquid structure and in-situ observation results, we discussed the phase selection mechanism between crystal and glass states. © 2009 Materials Research Society.

  343. Liquid structures of metallic glass-forming binary Zr alloys

    Akitoshi Mizuno, Toshihiko Akimoto, Masahito Watanabe, Shinji Kohara, Masaki Takata

    Materials Research Society Symposium Proceedings 1152 12-17 2008年

    DOI: 10.1557/proc-1152-tt03-06  

    ISSN:0272-9172

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    We have analyzed liquid structures of the binary Zr-TM (TM=Pd, Cu, Ni) alloys as a function of composition to investigate relations with their glass-forming abilities. High-energy x-ray (E=113 keV) diffraction experiments were performed and a conical nozzle levitation (CNL) technique was applied to achieve a containerless condition for highly reactive melts with high temperature. Structure information of the liquid alloys has been obtained with the aid of reverse Monte Carlo simulation. A shoulder was found at high-Q side of the second peak for the structure factor for Zr70Pd30 as well as Zr70Cu30 alloy Zr70Cu50 alloys, which can be indication of the formation of ISRO in the liquid alloys. Liquid Zr-Ni alloys shows an apparent difference in the structure factors between the Zr70Ni30 and the Zr50Ni 50 alloys, which can be associated with the formation of the chemical short range ordering, whereas the Zr-Pd alloys show a typical random distribution of atoms. © 2009 Materials Research Society.

  344. The MEM/Rietveld method with nano-applications - Accurate charge-density studies of nano-structured materials by synchrotron-radiation powder diffraction

    Masaki Takata

    Acta Crystallographica Section A: Foundations of Crystallography 64 (1) 232-245 2008年1月1日

    DOI: 10.1107/S010876730706521X  

    ISSN:0108-7673

    eISSN:1600-5724

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    Structural studies of materials with nano-sized spaces, called nano-structured materials, have been carried out by high-resolution powder diffraction. Our developed analytical method, which is the combination of the maximum-entropy method (MEM) and Rietveld refinement, the so-called MEM/Rietveld method, has been successfully applied to the analysis of synchrotron-radiation (SR) powder diffraction data measured at SPring-8, a third-generation SR light source. In this article, structural studies of nano-porous coordination polymers and endohedral metallofullerenes are presented with the advanced technique of SR powder experiment. The structure of the adsorbed guest molecule in the coordination polymer and encapsulated atoms in the fullerene cage are clearly revealed by the MEM charge density. The methodology of MEM/Rietveld analysis is also presented. © International Union of Crystallography 2008.

  345. Desorption-induced first-order phase transition in a cyano-bridged compound

    Y. Moritomo, F. Nakada, H. Kamioka, J. E. Kim, M. Takata

    Applied Physics Letters 92 (14) 2008年

    DOI: 10.1063/1.2908049  

    ISSN:0003-6951

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    The guest-host interaction is one of the promising tools to control the material state. Here, we found that a cyano-bridged compound Na0.50 Co [Fe (CN)6] 0.72 3.8 H2 O shows a first-order structural phase transition below a critical pressure Pc (150 Pa) at 300 K. Judging from suppression of the OH stretching mode in the infrared spectra, we ascribed the phase transition to desorption of the ligand waters. The phase transition accompanies a significant change of the visible absorption spectra, reflecting the strong hybridization between the Co eg state and the CN states. © 2008 American Institute of Physics.

  346. Ultra-high-precision time control system over any long time delay for laser pump and synchrotron x-ray probe experiment

    Yoshimitsu Fukuyama, Nobuhiro Yasuda, Jungeun Kim, Haruno Murayama, Takashi Ohshima, Yoshihito Tanaka, Shigeru Kimura, Hayato Kamioka, Yutaka Moritomo, Koshiro Toriumi, Hitoshi Tanaka, Kenichi Kato, Tetsuya Ishikawa, Masaki Takata

    Review of Scientific Instruments 79 (4) 2008年

    DOI: 10.1063/1.2906232  

    ISSN:0034-6748

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    An ultra-high-precision clock system for long time delay has been developed for picosecond time-resolved x-ray diffraction measurements using synchrotron radiation (SR) pulses and synchronized femtosecond laser pulses. The time delay control between pump laser pulse and the probe SR pulse was achieved by combining an in-phase quadrature modulator and a synchronous counter. This method allowed us to change the delay time by a nearly infinite amount while maintaining the precision of ±8.40 ps. Time-resolved diffraction measurements using the delay control system were demonstrated for precise measurement of an acoustic velocity in a single crystal of gallium arsenide. © 2008 American Institute of Physics.

  347. Very strong hydrogen bonds in a bent chain structure of fluorohydrogenate anions in liquid Cs (FH)2.3 F

    Shinji Kohara, Masaki Takata, Kazuhiko Matsumoto, Rika Hagiwara, Kentaro Suzuya, Hidetoshi Morita, Joan E. Siewenie, Chris J. Benmore

    Journal of Chemical Physics 129 (1) 2008年

    DOI: 10.1063/1.2944269  

    ISSN:0021-9606

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    The structure of liquid Cs (FH)2.3 F was revealed using a combination of high-energy x-ray and neutron diffraction measurements. We found that the strongest intermolecular H-F hydrogen bonds at an average distance of 1.36 Å are accompanied by the formation of a high degree of bending of the oligomer chain in the melt, with FHF=150°. A reverse Monte Carlo simulation showed that the average number of atoms per chain is 4.4. A detailed chain analysis of the atomic configuration revealed that (FH)2 F- oligomer chains are the major entities in the liquid, and asymmetrical FH F- are formed owing to the strong H-F hydrogen bonds. The results suggest that an average of one or two HF molecules bond to each of the 11 fluorine atoms surrounding a cesium ion. © 2008 American Institute of Physics.

  348. Using XRD for the modelling of interactions in (guest-host) systems: Success and pitfalls

    E. Borissenko, F. Porcher, I. Jui Hsu, Yu Wang, K. Kato, M. Takata, M. Souhassou, C. Lecomte

    Studies in Surface Science and Catalysis 174 (SUPPL. PART A) 721-724 2008年

    DOI: 10.1016/S0167-2991(08)80298-4  

    ISSN:0167-2991

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    Powder, and seldom single crystal diffraction, provides the first structural information about zeolites. However, because it is unable to take account of local defects or disorder, diffraction has to be supplemented ancillary information e.g. from local spectroscopies. The resulting structure may be used subsequently as a starting point for molecular dynamics/Monte Carlo studies of (guest-host) systems that gives in their turn new insight on the structural hypotheses assumed during diffraction data refinement. © 2008 Elsevier B.V. All rights reserved.

  349. Synchrotron powder diffraction characterization of the zeolite-based (p-N,N-dimethylnitroaniline-mordenite) guest-host phase

    Florence Porcher, Elena Borissenko, Mohamed Souhassou, Masaki Takata, Kenichi Kato, Juan Rodriguez-Carvajal, Claude Lecomte

    Acta Crystallographica Section B: Structural Science 64 (6) 713-724 2008年

    DOI: 10.1107/S0108768108025287  

    ISSN:0108-7681

    eISSN:0108-7681

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    The crystal structure of a new phase consisting of the inclusion of the hyperpolarizable molecule p-N,N-dimethylnitroaniline (dimethyl-para-nitroaniline or dmpNA) in the large-pore zeolite mordenite (MOR) has been determined from high-resolution synchrotron powder diffraction at 300 and 90 K. The unit-cell parameters and space group at 300 K are similar to those of as-synthesized mordenite. The crystallographic study indicates that the MOR straight channels are almost fully loaded with molecules that are disordered over eight symmetry-related sites. As expected, the molecules are located in the large 12-membered ring channel, at the intersection with the secondary eight-membered channel with which they might form hydrogen bonds. The elongation axes (and then the dipole moments) of the molecules are slightly tilted (28.57°) from [001]. The configuration found suggests an interaction of dmpNA with framework O atoms through its methyl groups. © International Union of Crystallography 2008.

  350. Structural studies of disordered materials using high-energy x-ray diffraction from ambient to extreme conditions

    Shinji Kohara, Masayoshi Itou, Kentaro Suzuya, Yasuhiro Inamura, Yoshiharu Sakurai, Yasuo Ohishi, Masaki Takata

    Journal of Physics Condensed Matter 19 (50) 2007年12月19日

    DOI: 10.1088/0953-8984/19/50/506101  

    ISSN:0953-8984

    eISSN:1361-648X

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    High-energy x-rays from a synchrotron radiation source allow us to obtain high-quality diffraction data for disordered materials from ambient to extreme conditions, which is necessary for revealing the detailed structures of glass, liquid and amorphous materials. We introduced high-energy x-ray diffraction beamlines and a dedicated diffractometer for glass, liquid and amorphous materials at SPring-8 and report the recent developments of ancillary equipment. Furthermore, the structures of liquid and amorphous materials determined from the high-energy x-ray diffraction data obtained at SPring-8 are discussed. © IOP Publishing Ltd.

  351. Extended charge-transfer state of RbMn[Fe(CN) <inf>6</inf>]

    Kenichi Kato, Yutaka Moritomo, Hiroshi Tanaka, Hiroko Tokoro, Shin Ichi Ohkoshi, Masaki Takata

    Journal of the Physical Society of Japan 76 (12) 2007年12月

    DOI: 10.1143/JPSJ.76.123602  

    ISSN:0031-9015

    eISSN:1347-4073

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    Based on the maximum entropy method (MEM) charge density, we have visualized the electrostatic potential of a charge-transfer compound, RbMn[Fe(CN) 6], which shows the charge-transfer transition from the nominal Mn 2+-Fe 3+ configuration to the Mn 3+-Fe 2+ one below 220 K. In the low-temperature phase, the transferred electron spreads over the hexacyanoferrate ([Fe(CN) 6]) via the strong Fet 2g-CNπ* hybridization. Such an extended charge-transfer state is responsible for the relatively strong ferromagnetic coupling between the neighbouring Mn 3+ spins. ©2007 The Physical Society of Japan.

  352. Crystal structures and phase transitions in Ba<inf>2</inf>HoTaO<inf>6</inf>

    Brendan J. Kennedy, Paul J. Saines, Yoshiki Kubota, Chiharu Minakata, Hiroko Hano, Kenichi Kato, Masaki Takata

    Materials Research Bulletin 42 (11) 1875-1880 2007年11月6日

    DOI: 10.1016/j.materresbull.2007.07.027  

    ISSN:0025-5408

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    The structure of the cation-ordered double perovskite Ba2HoTaO6 was examined using synchrotron X-ray powder diffraction at fine temperature intervals over the range of 90-300 K. Ba2HoTaO6 has a cubic structure in space group F m over(3, ̄) m at room temperature. A proper ferroelastic phase transition to I4/m tetragonal symmetry occurs near approximately 260 K. Analysis of the spontaneous tetragonal strain versus temperature indicated that the phase transition is second order in nature. © 2007 Elsevier Ltd. All rights reserved.

  353. Structures and crystal chemistry of the double perovskites Ba<inf>2</inf>LnB′O<inf>6</inf> (Ln=lanthanide and B′=Nb, Ta):. Part II-Temperature dependence of the structures of Ba<inf>2</inf>LnB′O<inf>6</inf>

    Paul J. Saines, Jarrah R. Spencer, Brendan J. Kennedy, Yoshiki Kubota, Chiharu Minakata, Hiroko Hano, Kenichi Kato, Masaki Takata

    Journal of Solid State Chemistry 180 (11) 3001-3007 2007年11月

    DOI: 10.1016/j.jssc.2007.08.010  

    ISSN:0022-4596

    eISSN:1095-726X

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    The structures of eight members of the series of double perovskites of the type Ba2LnB′O6 (Ln=La3+-Sm3+ and Y3+ and B′=Nb5+ and Ta5+) were examined both above and below room temperature using synchrotron X-ray powder diffraction. The La3+ and Pr3+ containing compounds had an intermediate rhombohedral phase whereas the other tantalates and niobates studied have a tetragonal intermediate. This difference in symmetry appears to be a consequence of the larger size of the La3+ and Pr3+ cations compared to the other lanthanides. The temperature range over which the intermediate symmetry is stable is reduced in those compounds near the point where the preferred intermediate symmetry changes from tetragonal to rhombohedral. In such compounds the transition to the cubic phase involves higher order terms in the Landau expression. This suggests that in this region the stability of the two intermediate phases is similar. © 2007 Elsevier Inc. All rights reserved.

  354. Observation of gas molecules adsorbed in the nanochannels of porous coordination polymers by the in situ synchrotron powder diffraction experiment and the MEM/Rietveld charge density analysis

    Yoshiki Kubota, Masaki Takata, Tatsuo C. Kobayashi, S. Kitagawa

    Coordination Chemistry Reviews 251 (21-24) 2510-2521 2007年11月

    DOI: 10.1016/j.ccr.2007.07.025  

    ISSN:0010-8545

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    Microporous coordination polymers have attracted attention for their numerous nanotechnology and engineering applications. Nano-coordination space provides some unique properties and functions that could never be realized in conventional porous materials. For the strategy of rational designs and the syntheses of novel porous coordination polymers, the structural information of adsorbed guest molecules inside the nanopores and the host framework is very important. In the present study, we describe the technique of the direct observation of gas molecules adsorbed in the nanochannels of porous coordination polymers by the in situ synchrotron powder diffraction measurement of gas adsorption and the maximum entropy method (MEM)/Rietveld charge density analysis. Specific alignment and properties of molecular oxygen obtained by gas adsorption in the nano-coordination space are revealed. © 2007 Elsevier B.V. All rights reserved.

  355. Isotope effect in Lix ZrNCl superconductors

    Y. Taguchi, T. Kawabata, T. Takano, A. Kitora, K. Kato, M. Takata, Y. Iwasa

    Physical Review B - Condensed Matter and Materials Physics 76 (6) 2007年8月8日

    DOI: 10.1103/PhysRevB.76.064508  

    ISSN:1098-0121

    eISSN:1550-235X

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    The N-isotope effect has been investigated for a series of layered superconductors Lix ZrNCl with small carrier density. The N-vibration phonon mode around 615 cm-1 interacting most strongly with electronic system has shown softening by about 20 cm-1 (=3.3%) upon N15 substitution. On the other hand, the decrease in the superconducting critical temperature (Tc) upon N15 substitution has been found to be only 0.06±0.03 K (=0.5±0.3%). This small change in Tc corresponds to an isotope shift coefficient α=0.07±0. 04, which is much smaller than the conventional value of 0.5, implying the relevance of other fluctuations than the phonon to the pairing interaction. © 2007 The American Physical Society.

  356. Charge-transfer transition in two-dimensional Cs [Co (3-cyanopyridine)2] [W (CN)8]·H2 O as investigated by angle-resolved x-ray diffraction

    J. E. Kim, Y. Ohishi, Y. Moritomo, K. Kato, M. Takata, S. Ohkoshi

    Physical Review B - Condensed Matter and Materials Physics 76 (1) 2007年7月13日

    DOI: 10.1103/PhysRevB.76.014106  

    ISSN:1098-0121

    eISSN:1550-235X

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    The structural properties were investigated for a two-dimensional cobalt octacyanotungsten, which shows temperature- and photoinduced charge-transfer (CT) transitions, by means of the synchrotron-radiation x-ray powder diffraction. We have found that the Co-W sheet nearly keeps the shape, but enlarges in size, at the CT transition from the Co3+ - W4+ configuration to the Co2+ - W5+ configuration. Based on the systematic investigation of the thermal treatment and photoirradiation effects on the structural properties, we will discuss the mechanism for the photoinduced CT transition. © 2007 The American Physical Society.

  357. Anion incorporation-induced cage deformation in 12CaO·7Al <inf>2</inf>O <inf>3</inf> crystal

    Takatoshi Nomura, Katsuro Hayashi, Yoshiki Kubota, Toshio Kamiya, Masahiro Hirano, Masaki Takata, Hideo Hosono

    Chemistry Letters 36 (7) 902-903 2007年7月5日

    DOI: 10.1246/cl.2007.902  

    ISSN:0366-7022

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    Effects of O 2- or OH - ion incorporation on the cage geometry in 12CaO·7Al 2O 3 (C12A7) crystals are examined by the maximum entropy method (MEM)/Rietveld analyses of synchrotron powder X-ray diffraction data. Presence of an extraframework anion in a cage causes inward displacements of two Ca 2+ ions axially coordinating to the anion. The OHion locates at the cage center and induces smaller symmetric displacements of the two Ca 2+ ions, while the O 2- ion likely locates on off-axis positions and induces larger asymmetric Ca 2+ ion displacements. Copyright © 2007 The Chemical Society of Japan.

  358. Structure-property relationship in the ordered-perovskite-related oxide Sr3.12 Er0.88 Co4 O10.5

    Shintaro Ishiwata, Wataru Kobayashi, Ichiro Terasaki, Kenichi Kato, Masaki Takata

    Physical Review B - Condensed Matter and Materials Physics 75 (22) 2007年6月22日

    DOI: 10.1103/PhysRevB.75.220406  

    ISSN:1098-0121

    eISSN:1550-235X

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    Synchrotron x-ray-diffraction patterns were measured and analyzed for a polycrystalline sample of the room-temperature ferromagnet Sr3.12 Er0.88 Co4 O10.5 from 300 to 650 K, from which two structural phase transitions were found to occur successively. The higher-temperature transition at 509 K is driven by ordering of the oxygen vacancies, which is closely related to the metallic state at high temperatures. The lower-temperature transition at 360 K is of first order, at which the ferromagnetic state suddenly appears exhibiting a jump in magnetization and resistivity. Based on the refined structure, possible spin and orbital models for the magnetic order are proposed. © 2007 The American Physical Society.

  359. Structure-property relationship in the ordered-perovskite-related oxide Sr3.12Er0.88Co4O10.5 査読有り

    Shintaro Ishiwata, Wataru Kobayashi, Ichiro Terasaki, Kenichi Kato, Masaki Takata

    PHYSICAL REVIEW B 75 (22) 2007年6月

    出版者・発行元:AMER PHYSICAL SOC

    DOI: 10.1103/PhysRevB.75.220406  

    ISSN:2469-9950

    eISSN:2469-9969

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    Synchrotron x-ray-diffraction patterns were measured and analyzed for a polycrystalline sample of the room-temperature ferromagnet Sr3.12Er0.88Co4O10.5 from 300 to 650 K, from which two structural phase transitions were found to occur successively. The higher-temperature transition at 509 K is driven by ordering of the oxygen vacancies, which is closely related to the metallic state at high temperatures. The lower-temperature transition at 360 K is of first order, at which the ferromagnetic state suddenly appears exhibiting a jump in magnetization and resistivity. Based on the refined structure, possible spin and orbital models for the magnetic order are proposed.

  360. Structures of stable and metastable Ge<inf>2</inf>Bi<inf>2</inf>Te <inf>5</inf>, an intermetallic compound in a GeTe-Bi<inf>2</inf>Te<inf>3</inf> pseudobinary system

    Toshiyuki Matsunaga, Rie Kojima, Noboru Yamada, Kouichi Kifune, Yoshiki Kubota, Masaki Takata

    Acta Crystallographica Section B: Structural Science 63 (3) 346-352 2007年5月16日

    DOI: 10.1107/S0108768107000778  

    ISSN:0108-7681

    eISSN:0108-7681

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    Ge2Bi2Te5 in the GeTe-Bi2Te3 pseudobinary system has two single-crystalline phases: a metastable phase with an NaCl-type structure and a stable phase with a nine-layer trigonal structure. In the metastable phase, the structure consists, in the hexagonal notation, of infinitely alternating stacks of Te and Ge/Bi layers at equal intervals along the c axis. On the other hand, in the stable phase those two layers are stacked alternately nine times to form an NaCl block. The blocks are then piled to construct a nine-layered trigonal structure with cubic close-packed stacking. Both ends of each block are covered with Te layers, contrary to the infinite alternation of Ge/Bi and Te layers in the structure of the metastable phase. The Ge/Bi layers in the metastable phase contain as much as 20 at. % vacancies; on the other hand, those in the stable phase are filled with atoms. These two crystalline phases in Ge2Bi2Te5 have identical atomic configurations to the two corresponding phases found in Ge2Sb2Te5. © International Union of Crystallography 2007.

  361. Modification of spin crossover behavior through solvent assisted formation and solvent inclusion in a triply interpenetrating three-dimensional network

    Matthias Bartel, Alina Absmeier, Guy N.L. Jameson, Franz Werner, Kenichi Kato, Masaki Takata, Roman Boca, Miki Hasegawa, Kurt Mereiter, Andrea Caneschi, Wolfgang Linert

    Inorganic Chemistry 46 (10) 4220-4229 2007年5月14日

    DOI: 10.1021/ic070173q  

    ISSN:0020-1669

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    The 3D coordination polymer [Fe(4ditz)3](PF6) 2·Solv consists of three interpenetrating infinite networks. There are cavities between iron atoms of different networks, which are partly filled with solvent molecules. With a change of the solvent used during synthesis from methanol to ethanol, the magnetic behavior of the materials changes. Both show an abrupt two-step spin crossover from low spin (S = 0) to high spin (S = 2) with the methanolate curve lying 7 K higher and showing a small hysteresis. Single crystal and powder diffraction studies show that they both have the same structure, but in powder form, the methanolate slowly loses methanol to finally leave about 0.075 MeOH/Fe. In comparison, the bigger ethanol remains at 0.25 EtOH/Fe. These results, in conjunction with thermodynamic data, strongly suggest that the differences in magnetic behavior are largely entropic in nature. Possible reasons for this are discussed. © 2007 American Chemical Society.

  362. Magnetic properties and crystal structure of solvent-free Sc@C<inf>82</inf> metallofullerene microcrystals

    Yasuhiro Ito, Wataru Fujita, Toshiya Okazaki, Toshiki Sugai, Kunio Awaga, Eiji Nishibori, Masaki Takata, Makoto Sakata, Hisanori Shinohara

    ChemPhysChem 8 (7) 1019-1024 2007年5月14日

    DOI: 10.1002/cphc.200700097  

    ISSN:1439-4235

    eISSN:1439-7641

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    Magnetic properties of solvent-free crystals of the endohedral Sc@C 82 are investigated by SQUID and X-ray powder diffraction. We find that the crystal is a paramagnet and the magnetic susceptibility decreases from 150 K with evidence of antiferromagnetic-like interactions by slow cooling. X-ray crystal analysis reveals the presence of a phase transition at 150 K, which is attributed to an orientational ordering transition of the fullerene molecules. At low temperatures we find a magnetic metastable state that can be controlled by the cooling rate. The metastable state can be formed by rapid cooling. The direction of Sc@C82 molecular axis in the crystals is disordered in the metastable state, and the susceptibility is higher than that in the slow cooling case at low temperature. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.

  363. Metallic state in a lime-alumina compound with nanoporous structure

    Sung Wng Kim, Satoru Matsuishi, Takatoshi Nomura, Yoshiki Kubota, Masaki Takata, Katsuro Hayashi, Toshio Kamiya, Masahiro Hirano, Hideo Hosono

    Nano Letters 7 (5) 1138-1143 2007年5月

    DOI: 10.1021/nl062717b  

    ISSN:1530-6984

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    We report a metallic state in a nanostructured porous crystal 12CaO-7Al2O3 by incorporating electrons in the inherent subnanometer-sized cages, in which a three-dimensionally closely packed cage structure acts as an electronic conduction path. High-density electron doping (∼2 x 1021 cm-3), which was achieved by a thermal treatment in Ti metal vapor at ∼1100 °C, induces homogenization of the cage geometry to a symmetric state, resulting in an insulator-metal transition with a sharp enhancement of the electron drift mobility from ∼0.1 to 4 cm2 V-1 s-1. The results provide an approach for the realization of electroactive functions in materials composed only of environmentally benign elements by utilizing the appropriate nanostructures. © 2007 American Chemical Society.

  364. In situ investigation of annealing effect on lamellar stacking structure of polyethylene thin films by synchrotron grazing-incidence small-angle and wide-angle X-ray scattering

    Sono Sasaki, Hiroyasu Masunaga, Hiroo Tajiri, Katsuaki Inoue, Hiroshi Okuda, Hiromichi Noma, Kohji Honda, Atsushi Takahara, Masaki Takata

    Journal of Applied Crystallography 40 (SUPPL. 1) 2007年4月

    DOI: 10.1107/S002188980700578X  

    ISSN:0021-8898

    eISSN:1600-5767

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    We have investigated lamellar stacking structure of melt-crystallized and annealed high-density polyethylene (HDPE) thin films, with a thickness of ca 400 nm prepared on silicon wafers, using synchrotron grazing-incidence small-angle and wide-angle X-ray scattering (GISWAXS) measurements at the BL40B2 beamline in SPring-8. In-situ measurements of GISWAXS were carried out for the films in a stepwise annealing process under vacuum. Scattering peaks relating to the long period, the average distance between stacked crystalline lamellae, were measured only in the in-plane direction near the Yoneda peak of the grazing-incidence small-angle X-ray scattering patterns. On the other hand, the orthorhombic (110) and (200) reflections of oriented HDPE crystals were measured in the out-of-plane direction of the grazing-incidence wide-angle X-ray scattering patterns. It was revealed that crystalline lamellae were stacked in a parallel direction to the film surface and the long period increased from ca 25 nm to ca 32 nm in a stepwise annealing process. Within a lamella, molecular chains were found to be packed regularly and the chain axis (the c axis) was relatively oriented parallel to the film surface. © International Union of Crystallography 2007.

  365. Electron density distributions in derivative crystals of α-rhombohedral boron

    Shizuka Hosoi, Hongki Kim, Tomohiro Nagata, Kazuhiro Kirihara, Kohei Soga, Kaoru Kimura, Kenichi Kato, Masaki Takata

    Journal of the Physical Society of Japan 76 (4) 2007年4月

    DOI: 10.1143/JPSJ.76.044602  

    ISSN:0031-9015

    eISSN:1347-4073

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    Boron carbide (B12C3) and boron phosphide (B 12P2) have the similar structures to α-rhombohedral boron (α-B12) and are considered to be derivative crystals of it. The peculiar bonds in these two derivative crystals are visualized by MEM/Rietveld analysis, which involves a combination of the maximum entropy method (MEM) and Rietveld refinement for powder X-ray diffraction (XRD) data. The distinctive bending of bonds observed in α-B12 is reversed by an insertion of other atoms. This bending arises from the conflict between the crystal structure of the rhombohedral lattice and the icosahedral structure of the B12 cluster. Bond strength and interatomic distances are also varied by the insertion. In order to estimate the bond strength, we obtained the electron density height at each bond critical point, and compared it with the force constant, which is derived from the Raman shift. ©2007 The Physical Society of Japan.

  366. Polarization study of non-resonant X-ray magnetic scattering from spin-density-wave modulation in chromium

    Hiroyuki Ohsumi, Masaki Takata

    Journal of Magnetism and Magnetic Materials 310 (2 SUPPL. PART 3) 2007年3月

    DOI: 10.1016/j.jmmm.2006.10.1002  

    ISSN:0304-8853

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    We present a polarization study of non-resonant X-ray magnetic scattering in pure chromium. Satellite reflections are observed at ± Q and ± 2 Q, where Q is the modulation wave vector of an itinerant spin-density-wave. The first and second harmonics are confirmed to have magnetic and charge origin, respectively, by means of polarimetry without using an analyzer crystal. This alternative technique eliminates intolerable intensity loss at an analyzer by utilizing the sample crystal also as an analyzer crystal. © 2006 Elsevier B.V. All rights reserved.

  367. Novel emission properties of melem caused by the heavy metal effect of lanthanides(III) in a LB film

    Ayumi Ishii, Koji Habu, Shinobu Kishi, Hideki Ohtsu, Tamikuni Komatsu, Keiichi Osaka, Kenichi Kato, Shigeru Kimura, Masaki Takata, Miki Hasegawa, Yuzo Shigesato

    Photochemical and Photobiological Sciences 6 (7) 804-809 2007年

    DOI: 10.1039/b703751c  

    ISSN:1474-905X

    eISSN:1474-9092

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    A novel emissive molecular system is constructed by the intercalation of the fluorophore melem (triamino-tri-s-triazine) within a Langmuir-Blodgett (LB) film of stearic acid with the periodic arrangement of lanthanides (Ln(iii)), mainly Pr(iii) with supporting of Eu(iii). From emission spectra, decay curves, quantum yields and XPS measurements, it is clarified that the external heavy metal effect of Pr(iii) on melem is much stronger in the film than in the bulk solid state, resulting in producing an unusual triplet state of melem. The triplet state of melem in the LB film donates the excitation energy to Pr(iii) in the LB film, which is completely different from the energy transfer pathway of Pr-melem complex in the solid state through the singlet state of melem. © The Royal Society of Chemistry and Owner Societies.

  368. Accurate structure factors and experimental charge densities from synchrotron X-ray powder diffraction data at SPring-8

    Eiji Nishibori, Eiji Sunaoshi, Akihiro Yoshida, Shinobu Aoyagi, Kenichi Kato, Masaki Takata, Makoto Sakata

    Acta Crystallographica Section A: Foundations of Crystallography 63 (1) 43-52 2007年1月

    DOI: 10.1107/S0108767306047210  

    ISSN:0108-7673

    eISSN:1600-5724

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    Accurate structure factors of silicon and diamond have been experimentally determined from powder diffraction data measured at the third-generation synchrotron-radiation source SPring-8, BL02B2. The accuracy of the obtained structure factors has been evaluated by comparing with structure factors in the literature measured by the Pendellösung method and with some from theoretical calculations. The results indicate that the structure factors from powder data are accurate enough to discuss the experimental charge-density distributions of these materials. The number of structure factors of silicon determined in the present study is 104, which is three times more than that of previous Pendellösung data. The experimental charge densities have been obtained by the maximum-entropy method from the present structure factors. The charge densities at bond mid-points for silicon and diamond show good agreement with different kinds of theoretical calculations. The present study proved that the powder diffraction at SPring-8 is a promising method for determination of experimental charge density for a wider range of materials. © 2007 International Union of Crystallography - all rights reserved.

  369. Structure of glass and liquid studied with a conical nozzle levitation and diffraction technique

    A. Mizuno, S. Kohara, S. Matsumura, M. Watanabe, J. K.R. Weber, M. Takata

    Materials Science Forum 539-543 (PART 2) 2012-2017 2007年

    DOI: 10.4028/0-87849-428-6.2012  

    ISSN:0255-5476

    eISSN:1662-9752

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    Two topics are described for structure analyses of glass and liquid using a combination of conical nozzle levitation (CNL) technique and diffraction experiments. The structure of high-purity bulk forsterite (Mg 2SiO4) glass synthesized by a CNL technique has been determined by a combination of high-energy x-ray, neutron diffraction, and reverse Monte Carlo (RMC) modeling technique. The 3-dimensional atomic configuration derived from RMC modeling revealed that unusual network structure. In order to study structures of high-temperature and undercooled liquids, a CNL system has been developed and integrated with the two-axis diffractometer for glass, liquid, and amorphous materials at SPring-8, which is one of the third-generation synchrotron source. High-energy x-ray diffraction experiments were performed to obtain reliable diffraction data for the liquid phase of metallic glass-forming Zr-Cu binary alloys.

  370. Structure of Zr-Cu and Zr-Ni liquid alloys studied by high-energy x-ray diffraction

    A. Mizuno, T. Kaneko, S. Matsumura, M. Watanabe, S. Kohara, M. Takata

    Materials Science Forum 561-565 (PART 2) 1349-1352 2007年

    DOI: 10.4028/0-87849-462-6.1349  

    ISSN:0255-5476

    eISSN:1662-9752

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    In order to obtain an insight into the high glass-forming ability of bulk metallic glasses, we have analyzed liquid structures of the Zr-Cu and the Zr-Ni binary alloys with different compositions. High-energy (E = 113 keV) x-ray diffraction experiments were carried out for the liquid alloys levitated by a conical nozzle levitation (CNL) technique. While a peculiar shoulder on the second peak was observed in the structure factors of the Zr-Cu liquid alloys, those of the Zr70Ni30 and the Zr50Ni 50O liquids exhibit an asymmetric shape of the second peak. In addition, it was found that the effect of concentration variation in the liquid Zr-Ni alloys was significantly different from that of the liquid Zr-Cu alloys. The liquid structure analyses using the reverse Monte Carlo (RMC) simulation have clarified that a degree of the short-range correlation between the constituents in the liquids affects substantially the glass-forming ability of the binary Zr alloys.

  371. X-ray pinpoint structural measurement for nanomaterials and devices at BL40XU of the SPring-8

    Shigeru Kimura, Yutaka Moritomo, Yoshihito Tanaka, Hitoshi Tanaka, Koshiro Toriumi, Kenichi Kato, Nobuhiro Yasuda, Yoshimitsu Fukuyama, Jungeun Kim, Haruno Murayama, Masaki Takata

    AIP Conference Proceedings 879 1238-1241 2007年

    DOI: 10.1063/1.2436288  

    ISSN:0094-243X

    eISSN:1551-7616

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    The pulse characteristic and high coherent x-ray beam of SPring-8 allow us to investigate dynamics of chemical reactions and phase transition of materials caused by applied field. In order to realize such direct investigation, "x-ray pinpoint structural measurement", which is the advanced x-ray measurement technique in nanometer spatial scale and/or pico-second time scale, is being developed at SPring-8. The features of "x-ray pinpoint structural measurement" technique are, 1) spatial resolution: ∼ 100 nm, 2) time resolution: ∼ 40 ps, and 3) measurement under the photo-irradiation, electric field, magnetic field, high pressure and active devices. Using this technique, we will explore the novel concept and new phenomena for nanomaterials and/or devices, and also demonstrate their validity. © 2007 American Institute of Physics.

  372. A new attachment of the large Debye-Scherrer camera at BL02B2 of the SPring-8 for thin film X-ray diffraction

    Keiichi Osaka, Shigeru Kimura, Kenichi Kato, Masaki Takata

    AIP Conference Proceedings 879 1771-1774 2007年

    DOI: 10.1063/1.2436412  

    ISSN:0094-243X

    eISSN:1551-7616

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    We have developed a new attachment for thin film x-ray measurements equipped with the large Debye-Scherrer camera at BL02B2 of the SPring-8. It is quite easy to handle and control the attachment using user-friendly computer programs. It is also notable that the attachment realizes both low-glancing-angle incident beam condition and in-plane measurement condition. The attachment enables us to measure high precision x-ray diffraction data from many kinds of thin films with the Debye-Scherrer camera. Using this attachment we try to analyze some dimensionally controlled thin film structures. © 2007 American Institute of Physics.

  373. Structural investigation of Ge<inf>3</inf>Sb<inf>2</inf>Te<inf>6</inf>, an intermetallic compound in the GeTe-Sb<inf>2</inf>Te<inf>3</inf> homologous series

    Toshiyuki Matsunaga, Rie Kojima, Noboru Yamada, Kouichi Kifune, Yoshiki Kubota, Masaki Takata

    Applied Physics Letters 90 (16) 2007年

    DOI: 10.1063/1.2728030  

    ISSN:0003-6951

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    Ge3Sb2Te6 was analyzed in detail using an x-ray diffraction method. The crystal of this material in the space group R3̄m is characterized as a 33-layered cubic close-packed stacking structure. Te atoms fully occupy their specific layers, whereas Ge and Sb atoms are located in other layers thus causing partial atomic disordering. Te and Ge/Sb layers are laminated alternately 11 times to form a NaCl block. Electron density distributions in the crystal were obtained using the maximum entropy method and band calculation, which showed very good agreement with each other. Ge3Sb2Te6 is a compound semiconductor with a very narrow band gap. © 2007 American Institute of Physics.

  374. On-off optical switching of the magnetic and structural properties in a spin-crossover complex

    K. Kato, M. Takata, Y. Moritomo, A. Nakamoto, N. Kojima

    Applied Physics Letters 90 (20) 2007年

    DOI: 10.1063/1.2736213  

    ISSN:0003-6951

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    A photoexcitation is one of the promising external fields to control the material phases. Here, the authors have demonstrated that the magnetic and structural properties of a spin-crossover complex, Fe (phen)2 (NCS)2 (phen=1,10-phenanthroline), can be reversibly switched by the on-off action of the continuous photoexcitation at the same temperature. The structural data suggest that the density of the high-spin Fe2+ in the photoinduced phase is about 0.88. Suppressed atomic vibrations of the photoinduced phase exclude the conventional heating effect as the origin for the observed optical switching. © 2007 American Institute of Physics.

  375. Topotactic linear radical polymerization of divinylbenzenes in porous coordination polymers

    Takashi Uemura, Daisuke Hiramatsu, Yoshiki Kubota, Masaki Takata, Susumu Kitagawa

    Angewandte Chemie - International Edition 46 (26) 4987-4990 2007年

    DOI: 10.1002/anie.200700242  

    ISSN:1433-7851

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    (Figure Presented) In the groove: Radical polymerization of divinylbenzenes (DVBs) in the one-dimensional nanochannels of porous coordination polymers allows linearly extended topotactic polymerization without cross-linking (see picture). The main factors that influence this polymerization are the channel size and host framework flexibility. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.

  376. Grazing incident small angle x-ray scattering study of polymer thin films with embedded ordered nanometer cells

    Hideaki Yokoyama, Cedric Dutriez, Lei Li, Taichi Nemoto, Kenji Sugiyama, Sono Sasaki, Hiroyasu Masunaga, Masaki Takata, Hiroshi Okuda

    Journal of Chemical Physics 127 (1) 2007年

    DOI: 10.1063/1.2749724  

    ISSN:0021-9606

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    Analysis of nanostructures is of increasing importance with advances of nanotechnology. Embedded nanostructures in thin films in particular are of recent interest. Grazing incident small angle x-ray scattering (GISAXS) has been recognized to be a powerful method to probe such embedded nanostructures; however, quantitative analysis of scattering pattern is not always trivial due to complex refraction and reflection at surface and interfaces. We prepared nanocellular thin films using block copolymer template with carbon dioxide (C O2); CO2 "bubbles" were formed in the CO2 -philic block domains. Such nanocellular structures were analyzed by GISAXS and simulated using distorted wave Born approximation (DWBA). Unlike traditional transmission x-ray scattering, GISAXS requires a careful choice of incident angle to analyze the form factor of scatters embedded in a thin film. Nevertheless, the GISAXS measurements under optimized geometry with quantitative calculations using DWBA revealed that the nanocells are spherical and aligned in a single layer of hexagonal lattice and are surrounded by CO2 -philic block domains. © 2007 American Institute of Physics.

  377. Direct observation of oxygen stabilization in layered ferroelectric Bi3.25 La0.75 Ti3 O12

    Su Jae Kim, Chikako Moriyoshi, Sayaka Kimura, Yoshihiro Kuroiwa, Kenichi Kato, Masaki Takata, Yuji Noguchi, Masaru Miyayama

    Applied Physics Letters 91 (6) 2007年

    DOI: 10.1063/1.2768906  

    ISSN:0003-6951

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    Electron charge density distributions in layered ferroelectrics Bi4 Ti3 O12 (BiT) and Bi3.25 La0.75 Ti3 O12 (BLT) are investigated by analyzing high-energy synchrotron-radiation powder diffraction data using the maximum entropy method/Rietveld method. BiT shows that chemical bonding resulting from orbital hybridization is established between Bi-O in the perovskite layer only along the a axis, whereas BLT exhibits isotropic chemical bonding of BiLa-O with a high electron density both along the a and b axes. High endurance to polarization fatigue reported for BLT films is suggested to originate from the stabilization of oxygen in the perovskite layer due to the isotropic chemical bonding of BiLa-O. © 2007 American Institute of Physics.

  378. Development of synchrotron DSC/WAXD/SAXS simultaneous measurement system for polymeric materials at the BL40B2 in SPring-8 and its application to the study of crystal phase transitions of fluorine polymers

    Hiroyasu Masunaga, Sono Sasaki, Kohji Tashiro, Makoto Hanesaka, Masaki Takata, Katsuaki Inoue, Noboru Ohta, Naoto Yagi

    Polymer Journal 39 (12) 1281-1289 2007年

    DOI: 10.1295/polymj.PJ2007105  

    ISSN:0032-3896

    eISSN:1349-0540

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    A new system of rapidly-scanning DSC/WAXD/SAXS simultaneous measurements has been successfully developed at the BL40B2 in SPring-8, Japan. The combination of the ultra-bright and highly-directional X-ray beams with the highly-sensitive two-dimensional (2D) detectors such as an imaging plate (IP), a CCD detector and a flat panel (FP) detector has made it possible to perform the rapidly-scanning time-resolved measurements of WAXD and SAXS for the polymeric materials subjected to the various kinds of external field like temperature, tensile force, magnetic field, hydrostatic pressure, and so on. The experimental data about the phase transitions of vinylidene fluoridetrifluoroethylene copolymer with VDF 82 mol % content and poly(vinylidene fluoride) form I have been presented as actual examples, where the phase transitions of the polar crystal consisting of planar-zigzag chains to the gauche-type high-temperature phase have been confirmed definitely and the remarkable change in lamellar stacking structure could be detected in the temperature region immediately below the melting point. © 2007 The Society of Polymer Science.

  379. Bent (metal)<inf>2</inf>C<inf>2</inf> clusters encapsulated in (Sc<inf>2</inf>C<inf>2</inf>)@C<inf>82</inf>(III) and (Y<inf>2</inf>C<inf>2</inf>)@C<inf>82</inf>(III) metallofullerenes

    Eiji Nishibori, Masayuki Ishihara, Masaki Takata, Makoto Sakata, Yasuhiro Ito, Takashi Inoue, Hisanori Shinohara

    Chemical Physics Letters 433 (1-3) 120-124 2006年12月29日

    DOI: 10.1016/j.cplett.2006.11.008  

    ISSN:0009-2614

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    A systematic powder X-ray structure study for (Sc2C2)@C82(isomer III) and (Y2C2)@C82(III) is carried out by the MEM/Rietveld method by using high resolution synchrotron radiation powder data. In both fullerene materials, two carbon atoms are encapsulated in the cage and a M2C2 bent cluster is most likely formed in the cage. The obtained cage structure of Sc2C84(III) is C82-C3V(8), which is the same as those of (Y2C2)@C82(III) and Y2@C82(III). The charge density of C2 is located at the center of fullerene cage. Two scandium atoms show the rotational disorder, indicating the presence of a rapid hopping motion inside C82-C3V(8) cage. The inter-atomic distances between metal and carbon atoms on fullerene cage are 2.29 Å for (Sc2C2)@C82(III), which is 0.2 Å smaller than that of (Y2C2)@C82(III). © 2006 Elsevier B.V. All rights reserved.

  380. Chemical reaction-inspired crystal growth of a coordination polymer toward morphology design and control

    Shigeyuki Masaoka, Daisuke Tanaka, Hiroyuki Kitahata, Sumiko Araki, Ryotaro Matsuda, Kenichi Yoshikawa, Kenichi Kato, Masaki Takata, Susumu Kitagawa

    Journal of the American Chemical Society 128 (49) 15799-15808 2006年12月13日

    DOI: 10.1021/ja065254k  

    ISSN:0002-7863

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    This paper reports a novel crystal growth system of a coordination framework {[Cu3(CN)3{hat-(CN)3(OEt) 3}]}n (1) (hat-(CN)3(OEt)3 = 2,6,10-tricyano-3,7,11-triethoxy-1,4,5,8,9,12-hexaazatriphenylene). The coordination polymer is crystallized through the reaction of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (hat-(CN)6), ethanol, and copper(I) complex, involving the breaking and forming of covalent bonds. The crystal morphologies obtained in the present system contain dumbbells, cogwheels, and superlattices. Moreover, in the growth perpendicular to the c-axis, periodic ramification at regular interval is observed, affording superlattice morphologies. Observation of the growth of dumbbell crystals shows that the growth rates parallel and perpendicular to the crystallographic c-axis are quite different: the former shows a drastic change with the reaction duration, while the latter is almost constant. These results are reproduced as a simple reaction-diffusion system, indicating that chemical reactions on crystal surfaces play an important role in determining the macroscopic crystal morphologies. © 2006 American Chemical Society.

  381. Bonding nature and structural phase transition in fullerene based nanomaterials

    Dam Hieu Chi, Y. Iwasa, M. Takata

    Journal of Nanoscience and Nanotechnology 6 (12) 3888-3892 2006年12月

    DOI: 10.1166/jnn.2006.667  

    ISSN:1533-4880

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    Rare-earth-metal-doped fullerides with a nominal composition of R 3C 70 (R -Sm, Eu, Yb) adopt a pseudomonoclinic structure in which C 70 dimers glued with rare-earth ions are involved. High-temperature powder X-ray diffraction experiments revealed that the dimers undergo reversible first-order structural phase transitions, associated with reduction of the unit cell volume, similar to the results observed in previous high-pressure experiments. Structural analyses showed that C 70 molecules are realigned to form closely packed structures, causing a reduction of volume at high temperature. The derived charge density map indicates that the transitions can be regarded as reversible structural changes from fullerene dimers to monomers. These features are ascribed to the unique bonding nature of rare-earth C 70 compounds. Copyright © 2006 American Scientific Publishers All rights reserved.

  382. High-resolution analysis of (Sc<inf>3</inf>C<inf>2</inf>)@C<inf>80</inf> metallofullerene by third generation synchrotron radiation X-ray powder diffraction

    Eiji Nishibori, Ikuya Terauchi, Makoto Sakata, Masaki Takata, Yasuhiro Ito, Toshiki Sugai, Hisanori Shinohara

    Journal of Physical Chemistry B 110 (39) 19215-19219 2006年10月5日

    DOI: 10.1021/jp061740i  

    ISSN:1520-6106

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    The X-ray structure of Sc3C82 is redetermined by the MEM/Rietveld method by using synchrotron radiation powder data at SPring-8, where the C2 encapsulated structure available to discuss the Sc-Sc interatomic distances has been determined. The encapsulated three scandium atoms form a triangle shape. A spherical charge distribution originating from the C2 molecule is located at the center of the triangle. Interatomic distances between Sc and Sc are 3.61(3) Å in the triangle. The distance between Sc and the center of the C2 molecule is 2.07(1) Å. © 2006 American Chemical Society.

  383. Disorder of Pb atom in cubic structure of Pb(Zn<inf>1/3</inf>Nb <inf>2/3</inf>)O<inf>3</inf>-PbTiO<inf>3</inf> system

    Yoshihiro Terado, Su Jae Kim, Chikako Moriyoshi, Yoshihiro Kuroiwa, Makoto Iwata, Masaki Takata

    Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 45 (9 B) 7552-7555 2006年9月22日

    DOI: 10.1143/JJAP.45.7552  

    ISSN:0021-4922

    eISSN:1347-4065

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    The crystal structures of (1 - x)Pb(Zn1/3Nb2/3)O 3-xPbTiO3 (PZN-PT: 0 ≤ x ≤ 0.3) in the cubic phase at 650K have been investigated by analyzing the high-energy synchrotron-radiation (SR) powder diffraction data using the Rietveld method. It is found that the Pb atom does not settle at the ideal high-symmetry position with a harmonic thermal parameter. The split-atom method reveals that the Pb atom in the cubic phase is disordered and settles randomly at crystallographically equivalent positions slightly off-center of the cubic-corner site. The disordered directions of the Pb atom are significantly changed at the concentration x ∼ 0.15. This structural boundary found in the cubic phase is related to the appearance of the morphotropic phase boundary (MPB). © 2006 The Japan Society of Applied Physics.

  384. Stable top-up operation at SPring-8

    Hitoshi Tanaka, Masatoshi Adachi, Tsuyoshi Aoki, Takao Asaka, Alfred Baron, Shin Daté, Kenji Fukami, Yukito Furukawa, Hirofumi Hanaki, Naoyasu Hosoda, Tetsuya Ishikawa, Hiroaki Kimura, Kazuo Kobayashi, Toshiaki Kobayashi, Shinji Kohara, Noritaka Kumagai, Mitsuhiro Masaki, Takemasa Masuda, Sakuo Matsui, Akihiko Mizuno, Takeshi Nakamura, Takeshi Nakatani, Takashi Noda, Toru Ohata, Haruo Ohkuma, Takashi Ohshima, Masaya Oishi, Sigeki Sasaki, Jun Schimizu, Masazumi Shoji, Kouichi Soutome, Motohiro Suzuki, Shinsuke Suzuki, Yoshio Suzuki, Shirou Takano, Masaru Takao, Takeo Takashima, Hideki Takebe, Akihisa Takeuchi, Kazuhiro Tamura, Ryotaro Tanaka, Yoshihito Tanaka, Tsutomu Taniuchi, Yukiko Taniuchi, Kouji Tsumaki, Akihiro Yamashita, Kenichi Yanagida, Yoshitaka Yoda, Hiroto Yonehara, Tetsuhiko Yorita, Masamichi Yoshioka, Masaki Takata

    Journal of Synchrotron Radiation 13 (5) 378-391 2006年9月

    DOI: 10.1107/S0909049506022862  

    ISSN:0909-0495

    eISSN:1600-5775

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    Top-up operation allows SPring-8 to provide highly stable X-ray beams with arbitrary filling patterns. The implementation of top-up operation is described, with a focus on the simultaneous achievement of stability of stored current, beam orbit, purity of an isolated single bunch, and beam injection efficiency. Stored-current fluctuations have been routinely reduced to a level of 10 -3. Stored-beam oscillation on frequent beam injection, which was originally regarded as the most serious problem, has been successfully suppressed to a sufficiently low level that it never perturbs imaging experiments. Current impurities in nominally empty buckets have been reduced to a level of 10-9 over more than one week of operation, making possible the measurement of time-resolved spectra using high-current bunches. Finally, excellent injection efficiency, higher than 80%, is routinely obtained, even for small undulator gaps, which is critical for preventing radiation damage to insertion-device magnets and to reduce leakage radiation. The process of achieving highly stabilized top-up operation at SPring-8 and its utility for user experiments are described. © 2006 International Union of Crystallography Printed in Great Britain - all rights reserved.

  385. Metastable sorption state of a metal-organic porous material determined by in situ synchrotron powder diffraction

    Yoshiki Kubota, Masaki Takata, Ryotaro Matsuda, Ryo Kitaura, Susumu Kitagawa, Tatsuo C. Kobayashi

    Angewandte Chemie - International Edition 45 (30) 4932-4936 2006年7月24日

    DOI: 10.1002/anie.200600976  

    ISSN:1433-7851

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    (Figure Presented) Guest-responsive framework: Gas adsorption into a metal-organic porous material was studies in situ. Structure analysis of empty phase I, intermediate phase M as a metastable state of gas adsorption, and saturated phase S showed rearrangement of guest molecules and framework transformation in response to guest size, shape, and amount. The picture shows these changes for the superimposed phases M and S. © 2006 Wiley-VCH Verlag GmbH © Co. KGaA.

  386. P-446 Crystal Structure of Actin Complex with Aplyronine A, an Antitumor Substance of Marine Origin

    Suenaga Kiyotake, Kuroda Takeshi, Yamada Kiyoyuki, Kigoshi Hideo, Hirata Kunio, Takata Masaki, Kato Kenichi, Muraoka Shin, Yamamoto Masaki, Tanaka Hiroshi

    International Symposium on the Chemistry of Natural Products 2006 "P-446" 2006年7月23日

    出版者・発行元:天然有機化合物討論会

    DOI: 10.24496/intnaturalprod.2006.0__P-446_  

  387. Incommensurate to commensurate phase transition in a new spin-Peierls system TiOBr

    T. Sasaki, M. Mizumaki, T. Nagai, T. Asaka, K. Kato, M. Takata, Y. Matsui, J. Akimitsu

    Physica B: Condensed Matter 378-380 (SPEC. ISS.) 1066-1067 2006年5月1日

    DOI: 10.1016/j.physb.2006.01.417  

    ISSN:0921-4526

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    We report here on the observation of superlattice reflections in the new quasi-one-dimensional spin system TiOBr by electron and synchrotron radiation X-ray diffractions. We discussed on crystal symmetry and temperature dependence of superlattice reflections. Superlattice reflections can be observed at ( h, k + frac(1, 2), 0) below Tc 1 and ( h ± δh, k ± δk, 0) above Tc 1; ( h + k = 2 n ). We discussed the origin of two phase transitions, Tc 1 ( = 27 K ) and Tc 2 ( = 47 K ) in TiOBr. © 2006 Elsevier B.V. All rights reserved.

  388. Charge-transfer phase transition and ferromagnetism of iron mixed-valence complexes (n-C<inf>n</inf>H<inf>2n+1</inf>)<inf>4</inf>N[Fe<sup>II</sup>Fe <sup>III</sup>(dto)<inf>3</inf>] (n = 3-6; dto = C<inf>2</inf>O <inf>2</inf>S<inf>2</inf>)

    Miho Itoi, Yuuki Ono, Norimichi Kojima, Kenichi Kato, Keiichi Osaka, Masaki Takata

    European Journal of Inorganic Chemistry (6) 1198-1207 2006年3月20日

    DOI: 10.1002/ejic.200500560  

    ISSN:1434-1948

    eISSN:1099-0682

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    The iron mixed-valence complex, (n-C3H7) 4N[FeIIFeIII(dto)3] (dto = dithiooxalato) shows a charge-transfer (CT) phase transition at TCT = 122.4 K. In the vicinity of TCT, the spin state changes from Fe II (S = 2) - FeIII (S = 1/2) (high-temperature phase: HTP) to FeII (S = 0) - FeIII (S = 5/2) (low-temperature phase: LTP) accompanied by a charge transfer between FeII and Fe III. This complex also undergoes a ferromagnetic transition at 7 K in the LTP. In order to investigate the mechanism of the CT phase transition and the ferromagnetism, we have systematically synthesized (n-CnH 2n+1)4N[FeIIFeIII-(dto) 3] (n = 3-6), and have investigated their physical properties by magnetic susceptibility, powder X-ray diffraction measurements, and ESR spectroscopy. The compounds (n-CnH2n+1) 4N[FeIIFeIII(dto)3] (n = 3-6) display ferromagnetic phase transitions at 7 K, 7 K (& 13 K), 19.5 K, and 22 K, respectively. For n = 3 and 4, the CT phase transitions take place at T CT ≈ 120 K and TCT ≈ 140 K, respectively. For n = 5 and 6, on the other hand, the CT phase transition does not occur, and the spin configuration of FeII (S = 2) and FeIII (S = 1/2) corresponding to the HTP for n = 3 and 4 is stable between 2 K and 300 K. The cation size of (n-CnH2n+1)4N+ (n = 3-6) acts as an effective internal pressure which induces the CT phase transition and the ferromagnetic ordering in the [FeIIFeIII(dto) 3]-∞ layer. We also discuss the mechanism of the CT phase transition and the ferromagnetism induced by the charge-transfer interaction between FeII and FeIII. © Wiley-VCH Verlag GmbH & Co. KGaA, 2006.

  389. Single structure widely distributed in a GeTe-Sb<inf>2</inf>Te<inf>3</inf> pseudobinary system: A rock salt structure is retained by intrinsically containing an enormous number of vacancies within its crystal

    Toshiyuki Matsunaga, Rie Kojima, Noboru Yamada, Kouichi Kifune, Yoshiki Kubota, Yoshikazu Tabata, Masaki Takata

    Inorganic Chemistry 45 (5) 2235-2241 2006年3月6日

    DOI: 10.1021/ic051677w  

    ISSN:0020-1669

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    GeTe(1-x)-Sb2Te3(x) sputtered amorphous film was crystallized into a simple NaCl-type structure through instantaneous laser irradiation over a wide composition range from x = 0 to at least 2/3. When the ratio of Sb2Te3 increases, a vacancy is generated at every Na site for two Sb atoms. The fraction of vacancies, v(x), changes according to x/(1 + 2x), and the cubic root unit cell volume varies with a strong correlation to v(x). Through these created vacancies, valence electrons provided by adjacent Ge/Sb and Te atoms remain constant regardless of the composition, ensuring that these electrons occupy predominantly the bonding molecular orbitals. This results in crystal chemical stability, with the closed shell p-p bondings in the valence electrons arranging the crystal's atomic configuration into an NaCl-type structure. © 2006 American Chemical Society.

  390. Structure basis for antitumor effect of aplyronine A

    Kunio Hirata, Shin Muraoka, Kiyotake Suenaga, Takeshi Kuroda, Kenichi Kato, Hiroshi Tanaka, Masaki Yamamoto, Masaki Takata, Kiyoyuki Yamada, Hideo Kigoshi

    Journal of Molecular Biology 356 (4) 945-954 2006年3月3日

    DOI: 10.1016/j.jmb.2005.12.031  

    ISSN:0022-2836

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    Aplyronine A, isolated from the sea hare Aplysia kurodai, possesses an exceedingly potent antitumor effect in vivo and it is one of the promising candidates as an anticancer drug. This macrolide is known to depolymerize F-actin and inhibit the polymerization of actin by forming a 1:1 complex with monomeric actin. The first complex structure of actin-aplyronine A was determined via a synchrotron X-ray analysis at a 1.45 Å resolution. As expected, aplyronine A binds to a hydrophobic cleft composed of subdomains 1 and 3 of actin by intercalating its aliphatic tail part into the actin molecule as do the other reported F-actin depolymerizing agents. Unexpectedly, this complex structure shows the specific structural features around the trimethylserine moiety, revealed as an important moiety of aplyronine A for cytotoxicity against HeLa cells. Combining this result and our previous one, the moiety should strongly relate to the specific biological activity of aplyronine A; i.e. a potent antitumor effect. © 2005 Elsevier Ltd. All rights reserved.

  391. 特集「不規則性をもつ結晶, 超イオン導電体, 非晶質, ガラス, 融体の構造解析-不規則系・ランダム系の結晶学-」にあたって

    吉朝 朗, 杉山 和正, 八島 正知, 高田 昌樹

    日本結晶学会誌 48 (1) 2-2 2006年2月27日

    出版者・発行元:日本結晶学会

    DOI: 10.5940/jcrsj.48.2  

    ISSN:0369-4585

  392. A C<inf>2</inf> molecule entrapped in the pentagonal-dodecahedral Y <inf>2</inf> cage in Y<inf>2</inf>C<inf>2</inf>@C<inf>82</inf>(III)

    Eiji Nishibori, Shintaro Narioka, Masaki Takata, Makoto Sakata, Takashi Inoue, Hisanori Shinohara

    ChemPhysChem 7 (2) 345-348 2006年2月13日

    DOI: 10.1002/cphc.200500437  

    ISSN:1439-4235

    eISSN:1439-7641

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    Carbon-encapsulating metallofullerenes: A C2 molecule is entrapped in the pentagonal-dodecahedral charge density of Y2 in Y2C2@C82(III) according to the maximum entropy/Rietveld analysis of the synchrotron X-ray powder diffraction data, which clearly show an additional charge-density peak for C2 (blue) inside the pentagonal-dodecahedral Y2 cage (red) in Y 2C2@C82(III) (picture, left) but not in Y 2@C82(III) (right). © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.

  393. Fine size control of platinum on carbon nanotubes: From single atoms to clusters

    Yong Tae Kim, Kazuyoshi Ohshima, Koichi Higashimine, Tomoya Uruga, Masaki Takata, Hiroyoshi Suematsu, Tadaoki Mitani

    Angewandte Chemie - International Edition 45 (3) 407-411 2006年1月9日

    DOI: 10.1002/anie.200501792  

    ISSN:1433-7851

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    (Figure Presented) Bond formation between single Pt atoms and surface thiol groups is the result of the reduction of a Pt precursor in the presence of surface-thiolated carbon nanotubes. By setting the temperature of the following heat treatment, finely size-controlled and monodispersed Pt clusters were obtained from the dispersed single atoms (see picture). © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.

  394. Electron Charge Density Study on the Phase Transitions in Perovskite-Type Oxides

    Kuroiwa Yoshihiro, Aoyagi Shinobu, Nishibori Eiji, Sakata Makoto, Takata Masaki

    日露/CIS/バルチック強誘電体シンポジウム講演概要集 2006 9-9 2006年

    出版者・発行元:日露/CIS/バルチック強誘電体シンポジウム組織委員会

    DOI: 10.11533/rcbjsf.2006.0.9.0  

  395. Crystal symmetry and superlattice reflections in spin-Peierls system TiOBr

    T. Sasaki, T. Nagai, K. Kato, M. Mizumaki, T. Asaka, M. Takata, Y. Matsui, H. Sawa, J. Akimitsu

    Science and Technology of Advanced Materials 7 (1 SPEC. ISS.) 17-21 2006年1月

    DOI: 10.1016/j.stam.2005.11.002  

    ISSN:1468-6996

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    We have demonstrated the direct observation of the crystal symmetry by electron and synchrotron X-ray diffraction analyses. Although the crystal structure at room temperature can be explained by orthorhombic Pmmn symmetry in our powder X-ray diffraction analysis, we detected weak reflections which should be the forbidden reflections of the Pmmn symmetry by electron and synchrotron X-ray diffraction analyses using single-crystalline TiOBr samples. We concluded that the crystal symmetry of TiOBr is different from the orthorhombic Pmmn symmetry. In this report, we discuss the crystal symmetry on the basis of the subgroup of orthorhombic Pmmn at room temperature and low temperature below Tc1(=27 K). © 2005 Elsevier Ltd. All right Reserved.

  396. Analysis of Composite Structures on Barium Titanate Fine Particles using Synchrotron Radiation

    Takuya Hoshina, Hirofumi Kakemoto, Takaaki Tsurumi, Satoshi Wada, Masatomo Yashima, Kenichi Kato, Masaki Takata

    Key Engineering Materials 301 239-242 2006年

    DOI: 10.4028/0-87849-982-2.239  

    ISSN:1013-9826

    eISSN:1662-9795

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    The crystal structures of barium titanate (BaTiO3) fine particles with a size around 140 nm were investigated using a synchrotron radiation X-ray diffraction method. The observed diffraction pattern was analyzed by Rietveld method assuming several models. As a result, it is found that the BaTiO3 fine particles have composite structures include (a) a tetragonal region with a constant c/a ratio, (b) a tetragonal region with gradient c/a ratios and (c) a cubic region. In order to estimate these structures, the partial profile relaxation technique was applied in the Rietveld refinement. It is considered that the composite structure is important for the size effect on BaTiO3 fine particles.

  397. Relationship between superconductivity and crystal structure in NbB <inf>2+x</inf>

    H. Takagiwa, E. Nishibori, N. Okada, M. Takata, M. Sakata, J. Akimitsu

    Science and Technology of Advanced Materials 7 (1 SPEC. ISS.) 22-25 2006年1月

    DOI: 10.1016/j.stam.2005.11.015  

    ISSN:1468-6996

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    We have performed magnetic susceptibility measurements and precise crystal structure analysis of the nonstoichiometric NbB2+x superconductor to reveal the relationship between Tc and crystal structure. From magnetic susceptibility measurements, it was found that Tc increases from 2.2 to 5.8 K with x. The crystal structures including both chemical compositions and lattice constants were precisely determined by Rietveld refinement using synchrotron X-ray powder diffraction data with three different wavelengths. We found that interatomic Nb-B distance increases with T c. The charge density of NbB2+x was revealed by the maximum entropy method based on Rietveld refinement. We find the difference in the number of electrons in the Nb site and B layer for NbB2+xwith different compositions and Tc. © 2005 Elsevier Ltd. All right Reserved.

  398. Transport, magnetic, and structural properties of spinel MnTi2 O4 and the effect of V doping

    T. Sonehara, K. Kato, K. Osaka, M. Takata, T. Katsufuji

    Physical Review B - Condensed Matter and Materials Physics 74 (10) 2006年

    DOI: 10.1103/PhysRevB.74.104424  

    ISSN:1098-0121

    eISSN:1550-235X

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    We studied the transport, magnetic, and structural properties of spinel MnTi2 O4 and V-doped samples, MnTi2-x Vx O4, to clarify the relation between charge, spin, and orbital degrees of freedom of 3d electrons in this series of compounds. A structural phase transition occurs in MnTi2 O4 at 180 K, which is presumably dominated by the ordering of t2g orbitals, but it can be easily suppressed by the V doping to the Ti site. Associated with this suppression of the structural anomaly, a ferrimagnetic and electrically conducting state appears in MnTi2-x Vx O4 with finite values of x. Fairly large magnetoresistance was observed in this state, whose sign changes from positive to negative with an increase in the V concentration x. With approaching the other end of this series, MnV2 O4, the electrical resistivity increases again and another type of structural phase transition occurs at 53 K. Large magnetostriction was observed in MnV2 O4, the only compound in this series to have both a ferrimagnetic state and tetragonal lattice distortion. © 2006 The American Physical Society.

  399. Polymerization catalyzed by a rhodium/ferritin composite

    Takafumi Ueno, Satoshi Abe, Masako Suzuki, Kunio Hirata, Nobutaka Suzuki, Masaki Takata, Yoshihito Watanabe

    Polymer Preprints, Japan 55 (1) 1798 2006年

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    Recently, chemical application of protein cages has been one of the most attractive targets in the field of bio-nanotechnology. We report here construction of Rh(nbd)·apo-ferritin and the polymerization of phenylacetylene catalyzed by the composite. The crystal structure of Rh(nbd)·apo-ferritin indicates that a subunit of ferritin had three Rh binding sites and all of the sites are located on the interior. We attempted polymeriztion of phenylacetylene using the composite. The UV-vis spectra and GPC results showed that the polymerization proceeded in the ferritin cage.

  400. Structural basis for the fast phase change of Ge<inf>2</inf>Sb <inf>2</inf>Te<inf>5</inf>: Ring statistics analogy between the crystal and amorphous states

    Shinji Kohara, Kenichi Kato, Shigeru Kimura, Hitoshi Tanaka, Takeshi Usuki, Kentaro Suzuya, Hiroshi Tanaka, Yutaka Moritomo, Toshiyuki Matsunaga, Noboru Yamada, Yoshihito Tanaka, Hiroyoshi Suematsu, Masaki Takata

    Applied Physics Letters 89 (20) 2006年

    DOI: 10.1063/1.2387870  

    ISSN:0003-6951

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    The three-dimensional atomic configuration of amorphous Ge2 Sb2 Te5 and GeTe were derived by reverse Monte Carlo simulation with synchrotron-radiation x-ray diffraction data. The authors found that amorphous Ge2 Sb2 Te5 can be regarded as "even-numbered ring structure," because the ring statistics is dominated by four- and six-fold rings analogous to the crystal phase. On the other hand, the formation of Ge-Ge homopolar bonds in amorphous GeTe constructs both odd- and even-numbered rings. They believe that the unusual ring statistics of amorphous Ge2 Sb2 Te5 is the key for the fast crystallization speed of the material. © 2006 American Institute of Physics.

  401. Electrostatic potential of ferroelectric PbTiO3: Visualized electron polarization of Pb ion

    Hiroshi Tanaka, Yoshihiro Kuroiwa, Masaki Takata

    Physical Review B - Condensed Matter and Materials Physics 74 (17) 2006年

    DOI: 10.1103/PhysRevB.74.172105  

    ISSN:1098-0121

    eISSN:1550-235X

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    A different method is proposed to evaluate the electrostatic potential and electric field from x-ray diffraction data by using maximum entropy method. The efficiency of the method is revealed in the application to a ferroelectric material PbTiO3. Visualized electrostatic potential and electric field on the charge density distribution give a direct evidence for the dipolar polarization of the Pb ion. They show close agreement with results by ab initio calculations. © 2006 The American Physical Society.

  402. Investigation of molecular and lamellar aggregation structure of crystalline polymer thin films by synchrotron GIXD and GISAXS measurements

    Sono Sasaki, Hiroyasu Masunaga, Katsuaki Inoue, Osami Sakata, Hiroo Tajiri, Hiroshi Okuda, Hiromichi Noma, Kouji Honda, Atsushi Takahara, Masaki Takata

    Polymer Preprints, Japan 55 (2) 4314-4315 2006年

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    In this stuay, molecular and meso-scale structures sucn as molecular/Tamellar orientation ana lamellar stacking distance were investigated for HDPE thin films by synchrotron 2D-grazing-incidence wide-angle X-ray diffraction/small-angle X-ray scattering (SR-2D-GIXD/GISAXS) simultaneous measurements. A sample used in this study was additive free high-density polyethylene (HDPE). HDPE films with a thickness of ca. 400 nm were prepared onto Si wafers by a dip-coating method. The obtained films on the wafers were isothermally crystallized at a crystallization temperature of 373K from the melt. Afterward, some of the obtained films were treated at an annealing temperature (Ta) of 378K, 383K or 388K for 24 hours or annealed at each Ta in a stepwise heating from ca. 300K. In-situ and ex-situ measurements of 2D-GIXD/GISAXS for melt-crystallized and annealed films were carried out with imaging-plates at the BL40B2 beamline of SPring-8. The wavelength of incident X-rays was 0.15 nm and camera length was ca. 110 mm for GIXD and ca. 2180 mm for GISAXS. On the basis of 2D-GIXD patterns for HDPE thin films during a stepwise annealing, it was implied that the a axis of orthorhombic unit cell relatively oriented in the out-of-plane direction. Strong scatterings near Yoneda peak in the in-plane direction of 2D-GISAXSpatterns were detected for the films. The peak position of the scattering corresponds to the long period, the average distance between stacked crystalline lamellae. By annealing the film, the peak position of the scattering shifted to the lower qy range in the in-plane direction. These results indicated that crystalline lamellae were stacked in the parallel direction to the film surface and the long period became longer from ca. 25 nm to ca. 35 nm by annealing. In a lamella, chains were regularly packed and the chain axis (the c axis) was relatively oriented parallel to the film surface.

  403. Investigation of correlation between crystalline phase transition and lamellar morphorogy of vinylidene fluoride-trifluoroethylene copolymers by synchrotron DSC/WAXD/SAXS simultaneous measurements

    H. Masunaga, S. Sasaki, M. Hanesaka, K. Tashiro, M. Takata

    Polymer Preprints, Japan 55 (2) 3173-3174 2006年

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    Both of the crystalline forms I and II contribute to the ferroelectric phase transition for the Vinylidene fluoride-trifluoroethylene copolymer with VDF contents higher than 80 mol% The morphological change and its relation with the crystal structural change have not yet been clarified at all. We will report the experimental data concerning the simultaneous measurements of DSC/WAXD/SAXS during the heating and cooling process of VDF 82% copolymer samples. For the melt-quenched sample, the lamella formed with II form crystalline changed from II form to HT phase, and increase of a long period occurred a thickness of lamella at the same with a temperature rise. In the cooling process the lamella would be formed with I form crystalline and that formed with II form were observed.

  404. High-energy synchrotron X-ray diffraction study of high-temperature levitated liquids

    Shinji Kohara, Masaki Takata, Akitoshi Mizuno, Masahito Watanabe

    Proceedings - Electrochemical Society PV 2004-24 246-252 2006年

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    High-energy x-ray diffraction experiments were performed on amorphous silica at the high temperatures at high-energy x-ray diffraction beamline BL04B2 of SPring-8. The conical nozzle levitation system was integrated with a two-axis diffractometer for glass, liquid, and amorphous materials. The incident photon energy was 113.3 keV, and diffraction patterns were measured in a transmission geometry at 1330°C The magnitude of the first sharp diffraction peak (FSDP, Q ∼ 1.525 Å) in the total structure factor, S(Q), of amorphous silica significantly decreased at 1330°C, which has not been observed at temperatures lower than the glass transition temperature (T g=1180°C) in previous studies. Total correlation function, T(r), suggested that the 2nd Si-O correlation is disordered due to the increased thermal-vibrations of Si-O tetrahedra. The structural model obtained by reverse Monte Calro modelling suggested that the ring statistics is unchanged at high temperature, whereas SiO4 tetrahedra are distorted.

  405. Formation and characterization of crystalline molecular arrays of gas molecules in a 1-dimensional ultramicropore of a porous copper coordination polymer

    Ryo Kitaura, Ryotaro Matsuda, Yoshiki Kubota, Susumu Kitagawa, Masaki Takata, Tatsuo C. Kobayashi, Megumi Suzuki

    Journal of Physical Chemistry B 109 (49) 23378-23385 2005年12月15日

    DOI: 10.1021/jp054411j  

    ISSN:1520-6106

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    Molecules and atoms confined in a nanospace may have properties distinctly different from those of the bulk fluid, owing to the formation of a specific molecular array characteristic of nanospace. In situ synchrotron powder X-ray diffraction measurements have been used to observe confined guest molecules such as N2, O2, Ar, and CH4 in the well-regulated ultrarmicropore of a copper coordination polymer, 1 ([Cu 2(pzdc)2pyz]: pzdc = 2,3-pyrazinedicarboxylate and pyz = pyrazine). The obtained crystal structures indicate that guest molecules are confined in a linear fashion to form crystalline-like regular ordered arrays, in contrast to the situation in the gas and liquid state, even at temperatures above the boiling point, and the ordered arrays are characteristic of the kind of gas molecule and the geometrical and potential properties of the ultramicropore of 1. © 2005 American Chemical Society.

  406. High-energy X-ray diffraction study of liquid structure of metallic glass-forming Zr <inf>70</inf>Cu <inf>30</inf> alloy

    Akitoshi Mizuno, Seiichi Matsumura, Masahito Watanabe, Shinji Kohara, Masaki Takata

    Materials Transactions 46 (12) 2799-2802 2005年12月

    DOI: 10.2320/matertrans.46.2799  

    ISSN:1345-9678

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    High-energy X-ray diffraction experiments were performed for a metallic glass-forming Zr 70Cu 30 alloy in the liquid state at a high temperature. Conical nozzle levitation was applied as a containerless method of obtaining accurate structure information of a highly reactive melt. The total structure factor obtained for the liquid alloy above its melting point shows a particular shoulder on the second peak, which is probably an indication of local icosahedral short-range ordering typically observed in deeply undercooled liquids. This implies that short-range ordered clusters already exist even in the equilibrium liquid state of Zr-based metallic glass-forming alloys. © 2005 The Japan Institute of Metals.

  407. Space-group symmetry for the perovskite Ca<inf>0.3</inf>Sr <inf>0.7</inf>TiO<inf>3</inf>

    C. J. Howard, R. L. Withers, Z. Zhang, K. Osaka, K. Kato, M. Takata

    Journal of Physics Condensed Matter 17 (44) 2005年11月9日

    DOI: 10.1088/0953-8984/17/44/L01  

    ISSN:0953-8984

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    It is shown, using synchrotron x-ray powder diffraction at room temperature and above, by invoking geometrical and symmetry arguments, and most directly by electron diffraction, that the perovskite Ca0.3Sr 0.7TiO3 at room temperature is tetragonal with space-group symmetry I4/mcm. This is in accord with the common view (Ball et al 1998 J. Solid State Chem. 139 238-47). The proposition that the compound adopts a metrically tetragonal orthorhombic structure in space group Imma (Ranjan and Pandey 1999 J. Phys.: Condens. Matter 11 2247-58) cannot be sustained. © 2005 IOP Publishing Ltd.

  408. Magnetic-field switching of crystal structure in an orbital-spin-coupled system: MnV2O4

    K. Adachi, T. Suzuki, K. Kato, K. Osaka, M. Takata, T. Katsufuji

    Physical Review Letters 95 (19) 2005年11月4日

    DOI: 10.1103/PhysRevLett.95.197202  

    ISSN:0031-9007

    eISSN:1079-7114

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    We studied the magnetic and structural properties of spinel MnV2O4, which has S=5/2 spin with no orbital degrees of freedom on the Mn2+ site and S=1 spin and three orbital degrees of freedom on the V3+ site. We found that the ferrimagnetic ordering at TN=56.5K and the structural phase transition at Ts=53.5K are closely correlated in this compound and found a switching of crystal structure between cubic and tetragonal phases by the magnetic field. This phenomenon can be explained by the coupling between orbital and spin degrees of freedom in the t2g states of the V site. © 2005 The American Physical Society.

  409. Low-spin state structure of [Fe(chloroethyltetrazole)<inf>6</inf>](BF <inf>4</inf>)<inf>2</inf> obtained from synchrotron powder diffraction data

    Eva Dova, René Peschar, Masaki Takata, Eiji Nishibori, Henk Schenk, Arno F. Stassen, Jaap G. Haasnoot

    Chemistry - A European Journal 11 (20) 5855-5865 2005年10月7日

    DOI: 10.1002/chem.200500036  

    ISSN:0947-6539

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    The complex [Fe(teec)6]-(BF4)2 (teec = chloroethyltetrazole) shows a two-step complete spin-cross-over transition in the temperature range 300-90 K. Time-resolved synchrotron powder diffraction experiments have been carried out in this temperature range, and crystal structure models have been obtained from the powder patterns by using the parallel tempering technique. Of these models, the low-spin state structure at 90 K has been refined completely with Rietveld refinement. Its structural characteristics are discussed in relation to the high-spin state model and other spin-crossover compounds. The complex shows a remarkable anisotropic unit-cell parameter contraction that is dependent on the applied cooling rate. In addition, the possible important implications for the interpretation of spin-crossover behavior in terms of structural changes are discussed. © 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  410. Superconductivity and physical properties of Ba24Si100 determined from electric transport, specific-heat capacity, and magnetic susceptibility measurements

    Takeshi Rachi, Harukazu Yoshino, Ryotaro Kumashiro, Masaki Kitajima, Kensuke Kobayashi, Keiichi Yokogawa, Keizo Murata, Noriaki Kimura, Haruyoshi Aoki, Hiroshi Fukuoka, Syoji Yamanaka, Hidekazu Shimotani, Taishi Takenobu, Yoshihiro Iwasa, Takahiko Sasaki, Norio Kobayashi, Yuji Miyazaki, Kazuya Saito, Fangzhun Guo, Keisuke Kobayashi, Keiichi Osaka, Kenichi Kato, Masaki Takata, Katsumi Tanigaki

    Physical Review B - Condensed Matter and Materials Physics 72 (14) 2005年10月1日

    DOI: 10.1103/PhysRevB.72.144504  

    ISSN:1098-0121

    eISSN:1550-235X

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    Both Ba24Si100 and Ba24Ge100 with crystallographically identical structure are found to be superconducting at 1.4 and 0.27 K, respectively. Physical properties of this superconductor Ba24Si100 are studied by electric transport, specific heat capacity, and magnetic susceptibility measurements. The density of states at the Fermi level NEF=0.148 states eV-1(Siatom)-1 and a distinct jump of Cp at the superconducting transition temperature ΔCp=0.272JK-1mol-1 are obtained. An exponential fit of Cp below the superconducting states gives an energy gap 2Δ=0.423meV and shows that this is a superconductor having s-wave character or isotropic energy gap. On the basis of our experimental data other important physical parameters are also derived. © 2005 The American Physical Society.

  411. A study of structures and order parameters in antiferroelectric PbHfO <inf>3</inf> by synchrotron radiation

    Hideshi Fujishita, Yuya Ishikawa, Akira Ogawaguchi, Kenichi Kato, Eiji Nishibori, Masaki Takata, Makoto Sakata

    Journal of the Physical Society of Japan 74 (10) 2743-2747 2005年10月

    DOI: 10.1143/JPSJ.74.2743  

    ISSN:0031-9015

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    We present structures of PbHfO3 between 100 and 525 K analyzed by a Rietveld method using synchrotron radiation. Spontaneous strain of a perovskite sublattice could be excellently expressed by a conventional phenomenological theory in a room-temperature antiferroelectric phase. Pb shifts along the a-axis and the square root of the spontaneous strain showed similar dependence on temperature as expected from the theory below 200 K, while one of the shifts showed a slight deviation at high temperature. Disordered arrangement of Pb atoms in the cubic phase was found as in the cubic phase of PbZrO 3, though the direction of the disorder in PbHfO3 was not so obvious as that in PbZrO3. ©2005 The Physical Society of Japan.

  412. High-energy SR powder diffraction evidence of multisite disorder of Pb atom in cubic phase of PbZr<inf>1-x</inf>Ti<inf>x</inf>O<inf>3</inf>

    Yoshihiro Kuroiwa, Yoshihiro Terado, Su Jae Kim, Akikatsu Sawada, Yasuhisa Yamamura, Shinobu Aoyagi, Eiji Nishibori, Makoto Sakata, Masaki Takata

    Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 44 (9 B) 7151-7155 2005年9月22日

    DOI: 10.1143/JJAP.44.7151  

    ISSN:0021-4922

    eISSN:1347-4065

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    High-energy synchrotron-radiation (SR) powder diffraction experiments have been carried out to investigate the relationship between the crystal structure of the paraelectric phase in FbZr1-xTixO3, (PZT) and phase transition. The Rietveld refinement adopting the split-atom method reveals that the Pb atom in PZT, except PbTiO3 (x = 1), is settled at multisites in relevant directions from the corner site of an ideal cubic structure. Namely, the Pb atom is found to be disordered at 12 sites in the 〈110〉 directions in PbZrO3 (x = 0), and at 8 sites in the (111) directions in the Zr-rich region (0 < x < 0.5). The disordered motion of the Pb atom markedly changes at x = 0.5, and the 〈110〉 disorder is preferable in the Ti-rich region (0.5 < x < 1). The disordered characteristics of the Pb atom and the structural boundary observed at x = 0.5 in the paraelectric phase are significant for understanding of the mechanism of the order-disorder phase transition and appearance of a morphotropic phase boundary (MPB) in PZT. © 2005 The Japan Society of Applied Physics.

  413. Reverse spin transition triggered by a structural phase transition

    Shinya Hayami, Yuji Shigeyoshi, Motoko Akita, Katsuya Inoue, Kenichi Kato, Keiichi Osaka, Masaki Takata, Ryo Kawajiri, Tadaoki Mitani, Yonezo Maeda

    Angewandte Chemie - International Edition 44 (31) 4899-4903 2005年8月5日

    DOI: 10.1002/anie.200500316  

    ISSN:1433-7851

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    (Figure Presented) Reverse spin crossover (RSCO), the reversible spin transition from the high- to the low-spin state upon heating, was observed in [Co(Cn-terpy)2](BF4)2 (C n-terpy = terpyridine) equipped with a long alkoxy chain (AC) of n = 14 or 16 methylene units (see picture). The wide thermal hysteresis of the RSCO around room temperature could allow such compounds to be used as molecular switches. © 2005 Wiley-VCH Verlag GmbH & Co. KGaA.

  414. Single-component molecular conductor [Zn(tmdt)<inf>2</inf>] and related Zn complexes

    Kimiko Yamamoto, Emiko Fujiwara, Akiko Kobayashi, Yuichi Fujishiro, Eiji Nishibori, Makoto Sakata, Masaki Takata, Hisashi Tanaka, Yoshinori Okano, Hayao Kobayashi

    Chemistry Letters 34 (8) 1090-1091 2005年8月5日

    DOI: 10.1246/cl.2005.1090  

    ISSN:0366-7022

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    Single-component molecular conductors based on zinc complexes with filled 3d shells and extended-TTF ligands, [ZnL2] (L = tmdt, dmdt, and dt) were prepared. The crystal structure of semiconducting [Zn(tmdt)2] (ρ (rt) ≈ 50 Ω cm) was determined by the synchrotron radiation X-ray powder diffraction experiments. The molecule has a tetrahedral geometry and two ligand planes are almost perpendicular to each other. Copyright © 2005 The Chemical Society of Japan.

  415. Observation of phase transition with lattice distortion in the low-dimensional quantum spin system TiOBr by synchrotron X-ray diffraction -evidence of spin-Peierls transition?-

    Tomoyuki Sasaki, Masaichiro Mizumaki, Kenichi Kato, Yasuo Watabe, Yoshiki Nishihata, Masaki Takata, Jun Akimitsu

    Journal of the Physical Society of Japan 74 (8) 2185-2188 2005年8月

    DOI: 10.1143/JPSJ.74.2185  

    ISSN:0031-9015

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    Here, we report on the direct observation of lattice distortion in the new quasi-one-dimensional spin system TiOBr by X-ray diffraction experiment using synchrotoron radiation. By comparing the crystal structure between TiOBr and TiOCl, the difference in b-axis length was considered to play a key role in determining the physical properties of both systems. Using a single crystal sample of TiOBr, superlattice reflections were observed at (0, 1.5, 0) and (0, 2.5, 0). The temperature dependence of the superlattice reflections implied the first-order transition at Tc1 = 27 K. We discussed the phase transition and analyzed the data using a simple dimerization model. ©2005 The Physical Society of Japan.

  416. MEM charge density analysis of orbital-ordering of Nd<inf>0.35</inf>Sr <inf>0.65</inf>MnO<inf>3</inf>

    Kenichi Kato, Masaki Takata, Eiji Nishibori, Makoto Sakata, Noriaki Hamada, Yutaka Moritomo

    Journal of the Physical Society of Japan 74 (8) 2137-2140 2005年8月

    DOI: 10.1143/JPSJ.74.2137  

    ISSN:0031-9015

    eISSN:0031-9015

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    The charge density distribution of Nd0.35Sr 0.65MnO3 has been investigated by means of the maximum entropy method (MEM) using the synchrotron radiation (SR) X-ray powder diffraction data. In this compound, the anisotropic optical spectra reported by Tobe et al. [Phys. Rev. B 67 (2003) 140402(R)] suggest that the d 3z2-r2 orbital-ordering survives even at 600K (≫ TN = 260 K). Consistently, we observed an anisotropic charge density distribution around the Mn ion at 30K (≪ TN), indicating the long-range ordering of the d3z2-r2 orbital. At 300K (≥ TN), however, the charge density distribution becomes isotropic, suggesting the disappearance of the long-range orbital ordering. ©2005 The Physical Society of Japan.

  417. An anomalous endohedral structure of Eu@C <inf>82</inf> metallofullerenes

    Bao Yun Sun, Toshiki Sugai, Eiji Nishibori, Kenichi Iwata, Makoto Sakata, Masaki Takata, Hisanori Shinohara

    Angewandte Chemie - International Edition 44 (29) 4568-4571 2005年7月18日

    DOI: 10.1002/anie.200500876  

    ISSN:1433-7851

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    (Chemical Equation Presented) A question of symmetry: Unlike other mono-metallofullerenes, the cage structures of Eu@C 82 (isomers I and III) have been shown to have C s (no. 6) and C 2v symmetry, respectively, by the maximum entropy method using synchrotron X-ray powder diffraction data. In both isomers (see structures) the Eu ion (turquoise) is located near the top of the carbon cage adjacent to a C-C double bond. © 2005 Wiley-VCH Verlag GmbH & Co. KGaA.

  418. Pressure/temperature/substitution-induced melting of A-site charge disproportionation in Bi1-xLaxNiO3 (0≤x≤0.5)

    S. Ishiwata, M. Azuma, M. Hanawa, Y. Moritomo, Y. Ohishi, K. Kato, M. Takata, E. Nishibori, M. Sakata, I. Terasaki, M. Takano

    Physical Review B - Condensed Matter and Materials Physics 72 (4) 2005年7月15日

    DOI: 10.1103/PhysRevB.72.045104  

    ISSN:1098-0121

    eISSN:1550-235X

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    Metal-insulator transitions strongly coupled with lattice were found in Bi1-xLaxNiO3. Synchrotron x-ray powder diffraction revealed that pressure (P∼3GPa, T=300K), temperature (T∼340K, x=0.05), and La substitution (x∼0.075, T=300K) caused the similar structural change from a triclinic (insulating) to an orthorhombic (metallic) symmetry, suggesting melting of the A-site charge disproportionation. Comparing crystal structure and physical properties with the other ANiO3 series, an electronic state of the metallic phase can be described as [A3+L δ, Ni2+L 1-δ], where a ligand-hole L contributes to a conductivity. We depicted a schematic P-T phase diagram of BiNiO3 including a critical point (3 GPa, 300 K) and an inhomogeneous region, which implies universality of ligand-hole dynamics in ANiO3 (A=Bi, Pr, Nd...). © 2005 The American Physical Society.

  419. Phase relationships of crystalline polymorphs of mesogenic 4-cyano-4′-heptyloxybiphenyl (7OCB) and 4-cyano-4′-octyloxybiphenyl (8OCB)

    Kayako Hori, Yuko Iwai, Megumi Yano, Reiko Orihara-Furukawa, Yasunori Tominaga, Eiji Nishibori, Masaki Takata, Makoto Sakata, Kenichi Kato

    Bulletin of the Chemical Society of Japan 78 (7) 1223-1229 2005年7月15日

    DOI: 10.1246/bcsj.78.1223  

    ISSN:0009-2673

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    Temperature-dependent X-ray diffraction (XRD) studies using synchrotron radiation and Raman spectral studies in the range of 40-850 cm-1 have been carried out for crystalline polymorphs of the title compounds in order to elucidate the phase relations of the polymorphs. Transition processes between metastable phases have been confirmed with structural evidence: square-plate (SP) crystal to needle (N) crystal for 7OCB and parallelpiped plate (PP) crystal to needle (N) crystal for 8OCB; these processes were previously proposed based on the results of differential scanning calorimetry. XRD study shows that a fourth phase of 7OCB, which appears during the stabilization process and hence is referred to as an intermediate phase, is a slightly but definitely different crystalline phase from the most stable phase. SP of 7OCB stabilizes in two steps: first to the intermediate phase, which then rearranges to the most stable phase at the melting point of the intermediate phase just below the melting point of the most stable phase or on keeping at RT for several months or longer. Some structural features of the most stable phases of 7OCB and 8OCB are discussed based on the unit cell parameters derived from the powder XRD results. © 2005 The Chemical Society of Japan.

  420. Highly controlled acetylene accommodation in a metal-organic microporous material

    Ryotaro Matsuda, Ryo Kitaura, Susumu Kitagawa, Yoshiki Kubota, Rodion V. Belosludov, Tatsuo C. Kobayashi, Hirotoshi Sakamoto, Takashi Chiba, Masaki Takata, Yoshiyuki Kawazoe, Yoshimi Mita

    Nature 436 (7048) 238-241 2005年7月14日

    DOI: 10.1038/nature03852  

    ISSN:0028-0836

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    Metal-organic microporous materials (MOMs) have attracted wide scientific attention owing to their unusual structure and properties, as well as commercial interest due to their potential applications in storage, separation and heterogeneous catalysis. One of the advantages of MOMs compared to other microporous materials, such as activated carbons, is their ability to exhibit a variety of pore surface properties such as hydrophilicity and chirality, as a result of the controlled incorporation of organic functional groups into the pore walls. This capability means that the pore surfaces of MOMs could be designed to adsorb specific molecules; but few design strategies for the adsorption of small molecules have been established so far. Here we report high levels of selective sorption of acetylene molecules as compared to a very similar molecule, carbon dioxide, onto the functionalized surface of a MOM. The acetylene molecules are held at a periodic distance from one another by hydrogen bonding between two non-coordinated oxygen atoms in the nanoscale pore wall of the MOM and the two hydrogen atoms of the acetylene molecule. This permits the stable storage of acetylene at a density 200 times the safe compression limit of free acetylene at room temperature.

  421. Specific Heat Capacity and Magnetic Susceptibility of Superconducting Ba24Si100 査読有り

    T.Rachi, H.Yoshino, R.Kumashiro, M.Kitajima, K.Kobayashi, K. Yokogawa, K. Murata, N. Kimura, H. Aoki, H. Fukuoka, S. Yamanaka, H.Shimotani, T.Takenobu, Y.Iwasa, T.Sasaki, N.Kobayashi, Y. Miyazaki, K. Saito, F.Z. Guo, K. Kobayashi, K. Osaka, K. Kato, M. Takata, K.Tanigaki

    Phys. Rev. B 72 144504 2005年6月

    DOI: 10.1103/PhysRevB.72.144504  

  422. Superconducting properties and crystallinity of as-grown MgB<inf>2</inf> thin films synthesized using an in-plane-lattice Near-matched epitaxial buffer layer

    T. Kato, K. Yamanaka, S. Yata, Ya Yamada, S. Kubo, Y. Yamada, A. Matsushita, O. Sakata, S. Kimura, M. Takata

    IEEE Transactions on Applied Superconductivity 15 (2 PART III) 3257-3260 2005年6月

    DOI: 10.1109/TASC.2005.848846  

    ISSN:1051-8223

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    As-grown MgB2 thin films were synthesized at a low temperature of 270°C on an in-plane-lattice-near-matched TiZr buffer layer grown on Al2O3 - C substrate and Al2O3 substrate without buffer. The critical temperature (Tc), critical current density (Jc) and crystallinity of MgB2 on TiZr buffered substrates were found to be high compared with those of MgB2 on Al2O3; the improved Tc was around 35 K and Jc 6.6 × 105 A/cm2 at 5 K under the magnetic field of 1 T perpendicular to the film surface. The epitaxial relationship of MgB2 thin film on buffer layer was MgB2 [01 - 10] || TiZr[01 - 10] || Al2O3[11 - 20], but MgB 2 thin film without buffer layer had no epitaxial relationship. © 2005 IEEE.

  423. 高エネルギー放射光およびコンピュータシミュレーションを用いた"乱れた構造"の三次元可視化

    小原 真司, 大石 泰生, 高田 昌樹, 米田 安宏, 鈴谷 賢太郎

    日本結晶学会誌 47 (2) 123-129 2005年4月27日

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.47.123  

    ISSN:0369-4585

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    The use of high-energy (<I>E</I> ≥ 50 keV) X-rays from SPring-8 allows us to perform X-ray diffraction experiments on disordered materials with the following advantages: high resolution in real space due to the wide range of scattering vector, small correction terms (particularly the absorption correction), and fast diffraction measurement with small amount of samples. Recently, high-energy X-ray diffraction data have been combined with neutron diffraction data from a pulsed neutron source to provide more detailed and reliable structural information than has hitherto been available. Furthermore, the use of reverse Monte Carlo modelling and PDF (pair distribution function) simulation based on high-energy X-ray diffraction data have succeeded in illustrating 3-dimensional structure of disordered materials and disorder in crystalline materials.

  424. Pressure-induced charge ordering of LiV<inf>2</inf>O<inf>4</inf>

    K. Takeda, H. Hidaka, H. Kotegawa, T. C. Kobayashi, K. Shimizu, H. Harima, K. Fujiwara, K. Miyoshi, J. Takeuchi, Y. Ohishi, T. Adachi, M. Takata, E. Nishibori, M. Sakata, T. Watanuki, O. Shimomura

    Physica B: Condensed Matter 359-361 (SPEC. ISS.) 1312-1314 2005年4月

    DOI: 10.1016/j.physb.2005.01.390  

    ISSN:0921-4526

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    The powder X-ray diffraction experiments of LiV2O4 have been performed at low temperature and high pressure using synchrotron radiation. In the isothermal experiment at 10 K, the cubic-rhombohedral phase transition corresponding to the metal-insulator transition is found at around 13 GPa. This transition seems to be due to charge ordering of V ions on the analogy of the metal-insulator transition in AlV2O4. © 2005 Elsevier B.V. All rights reserved.

  425. Direct observation of hydrogen molecules adsorbed onto a microporous coordination polymer

    Yoshiki Kubota, Masaki Takata, Ryotaro Matsuda, Ryo Kitaura, Susumu Kitagawa, Kenichi Kato, Makoto Sakata, Tatsuo C. Kobayashi

    Angewandte Chemie - International Edition 44 (6) 920-923 2005年2月2日

    DOI: 10.1002/anie.200461895  

    ISSN:1433-7851

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    Trapped hydrogen molecules in the nanochannels of a copper coordination polymer were successfully observed by the synchrotron powder-diffraction method. The adsorbed molecules are located near one corner of the rectangular nanochannels, and the pockets of the pore walls are suited to the size of the hydrogen molecules (see picture). These results could provide guidelines for the design of hydrogen-storage materials.

  426. Structure of High-pressure Liquids: X-ray Diffraction and RMC Modelling 査読有り

    Kohara Shinji, Akahama Yuichi, Ohishi Yasuo, Temleitner Laszlo, Pusztai Laszlo, Takata Masaki, Kawamura Haruki

    ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 61 C87-C88 2005年

    DOI: 10.1107/S0108767305096285  

    ISSN:2053-2733

  427. Evidence of L1<inf>0</inf> type ordered structure at an equiatomic composition PtCr

    Ananda Kumar Das, Taro Fujita, Anjana Asthana, Kenichi Kato, Masaki Takata, Ken Ichi Ohshima

    Journal of the Physical Society of Japan 74 (1) 498-499 2005年1月

    DOI: 10.1143/JPSJ.74.498  

    ISSN:0031-9015

  428. Evidence of a pressure-induced orbital transition in a layered manganite

    K. Kato, Y. Ohishi, M. Takata, E. Nishibori, M. Sakata, Y. Moritomo

    Physical Review B - Condensed Matter and Materials Physics 71 (1) 2005年1月

    DOI: 10.1103/PhysRevB.71.012404  

    ISSN:1098-0121

    eISSN:1550-235X

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    The charge density distribution of a bilayer manganite La 1.04Sr1.96Mn2O7 has been investigated by means of the maximum entropy method using the synchrotron radiation x-ray powder data. La1.04Sr1.96Mn 2O7 shows a layered-type (A-type) antiferromagnetic spin-ordering below TN≈200 K. We directly observed that application of pressure of several GPa at 17 K changes the orbital state from the two-dimensional dx2-y2 state to the three-dimensionally fluctuating state. This orbital transition, which is probably driven by the pressure-induced modification of the oxygen environment around the Mn site, causes the metallic conductivity as well as the ferromagnetism of the system. ©2005 The American Physical Society.

  429. Conducting and magnetic properties of 1-ethyl-3-methylimidazolium (EMI) salts containing paramagnetic irons: Liquids [EMI][M<sup>III</sup>Cl <inf>4</inf>] (M = Fe and Fe<inf>0.5</inf>Ga<inf>0.5</inf>) and solid [EMI] <inf>2</inf>[Fe<sup>II</sup>Cl<inf>4</inf>]

    Yukihiro Yoshida, Akihiro Otsuka, Gunzi Saito, Seiichi Natsume, Eiji Nishibori, Masaki Takata, Makoto Sakata, Masahide Takahashi, Toshinobu Yoko

    Bulletin of the Chemical Society of Japan 78 (11) 1921-1928 2005年

    DOI: 10.1246/bcsj.78.1921  

    ISSN:0009-2673

    eISSN:1348-0634

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    An EMI-based room-temperature (RT) ionic liquid containing d5 trivalent iron(III) ions [EMI][FeIIICl4] was fully investigated, where EMI is 1-ethyl-3-methylimidazolium. The viscosity of the salt is 14 cP at 30°C, and its ionic conductivity is as high as 1.8 × 10-2 S cm-1 at 20°C. The high conductivity and fluidity can be attributed to the reduced interionic Coulomb attractions owing to the nephelauxetic effect. Magnetic susceptibility shows the Curie-Weiss behavior arising from S = 5/2 high-spin electronic state on iron(III) ions in both liquid and solid states, leading to the conductive-paramagnetic bifunctional RT ionic liquid. The solidified salt passes through an antiferromagnetic transition at 4.2 K. Diamagnetic [EMI][GaIIICl 4] and paramagnetic [EMI][FeIIICl4] 0.5[GaIIICl4]0.5 are also RT ionic liquids and show similar conductivities (1.8-2.0 × 10-2 S cm-1 at 20°C) and viscosities (12-13 cP at 30°C). These results indicate that the influence of paramagnetic iron(III) ions upon the ionic conductivity and viscosity is negligible in the present system. A 2:1 EMI salt containing d 6 divalent iron(II) ions [EMI]2[FeIICl 4] melts at 86°C. Its crystal structure determined by a synchrotron X-ray powder diffraction measurement is analogous to those of the reported [EMI]2[CoIICl4] and [EMI] 2[NiIICl4] with expanded lattice. © 2005 The Chemical Society of Japan.

  430. Molecular aggregation structure of polyethylene thin films prepared on silicon substrates

    Sono Sasaki, Hirohiko Yakabe, Keiji Tanaka, Toshihiko Nagamura, Osami Sakata, Masaki Takata, Atsushi Takahara, Tisato Kajiyama

    Polymer Preprints, Japan 54 (2) 3303-3304 2005年

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    In this study, structural features of crystalline polymers at the solid surface were analyzed by synchrotron grazing-incidence X-ray diffraction (SR-GIXD) measurements. Thin films of high-density polyethylene (HDPE) were prepared on silicon substrates from a p-xylene solution by a dip-coating method. The dip-coated films and the dip-coated and melt-crystallized ones were annealed at temperatures (Ta) of 373K-393K under N 2 atmosphere. The in-plane GIXD measurement for the HDPE thin films was carried out at the BL13XU of SPring-8, Japan. Bragg diffraction from the near-surface and the bulk of the films was detected at incident angles smaller and larger than the critical angle, respectively. Comparison of the surface-sensitive GIXD data with the bulk one revealed that the dimensions of orthorhombic unit cell in the near-surface region were smaller than those in the bulk region. This might relate to thermal stress induced between the HDPE film and the silicon substrate in film preparation.

  431. Charge density study under high pressure

    Makoto Sakata, Takafumi Itsubo, Eiji Nishibori, Yutakata Moritomo, Norimichi Kojima, Yasuo Ohishi, Masaki Takata

    Journal of Physics and Chemistry of Solids 65 (12) 1973-1976 2004年12月

    DOI: 10.1016/j.jpcs.2004.08.028  

    ISSN:0022-3697

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    The experimental and analytical method of the high-pressure powder experiment at BL10XU, SPring-8, is described. There is no doubt that BL10XU must be one of the most appropriate beam lines for high pressure X-ray diffraction experiment taking advantage of third generation synchrotron source. As an example of the advanced charge density study under high pressure, the structural change of Cs2Au2Br6 by applying pressure is studied by Rietveld/MEM analysis. It reveals that the structural change of Cs2Au2Br6 by applying pressure occurs basically at electron level, such as valence state change and chemical bonding, which may be called the electronic phase transition. © 2004 Elsevier Ltd. All rights reserved.

  432. Motion of methanol adsorbed in porous coordination polymer with paramagnetic metal ions

    Satoshi Horike, Ryotaro Matsuda, Ryo Kitaura, Susumu Kitagawa, Takahiro Iijima, Kazunaka Endo, Yoshiki Kubota, Masaki Takata

    Chemical Communications (19) 2152-2153 2004年11月7日

    DOI: 10.1039/b406883a  

    ISSN:1359-7345

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    Molecular motions of methanol adsorbed in 1D nano-channels of pillared-layer coordination polymer with paramagnetic metal ions have been studied by 2H NMR together with X-ray crystallography.

  433. Guest shape-responsive fitting of porous coordination polymer with shrinkable framework

    Ryotaro Matsuda, Ryo Kitaura, Susumu Kitagawa, Yoshiki Kubota, Tatsuo C. Kobayashi, Satoshi Horike, Masaki Takata

    Journal of the American Chemical Society 126 (43) 14063-14070 2004年11月3日

    DOI: 10.1021/ja046925m  

    ISSN:0002-7863

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    In situ synchrotron X-ray powder diffraction patterns of porous coordination polymers {[Cu2-(pzdc)2(bpy)]·G} have been measured (pzdc = pyrazine-2,3-dicarboxylate, bpy = 4,4′-bipyridine) (where G = H2O for CPL-2 ⊃ H2O, G = benzene for CPL-2 ⊃ benzene, and G = void for the apohost). The structures of apohost and CPL-2 ⊃ benzene were determined from Rietveld analysis. Adsorption of benzene in the channels induced a remarkable contraction in the crystal (b axis; 6.8%, volume; 4.9%), although the channels were occupied by the benzene molecules. This crystal transformation provides a new pore structure that is well suited for benzene molecules, and we denote it as a "shape-responsive fitting" transformation. This type of pore gives rise to a new guideline: frameworks can be composed of flexible motifs that are linked via strong bond and/or stiff motifs that are connected via weaker bonds.

  434. Rational design and crystal structure determination of a 3-D metal-organic jungle-gym-like open framework

    Ryo Kitaura, Fumiyasu Iwahori, Ryotaro Matsuda, Susumu Kitagawa, Yoshiki Kubota, Masaki Takata, Tatsuo C. Kobayashi

    Inorganic Chemistry 43 (21) 6522-6524 2004年10月18日

    DOI: 10.1021/ic049005d  

    ISSN:0020-1669

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    A new three-dimensional (3-D) jungle-gym-like open metal-organic framework has been synthesized from a two-dimensional (2-D) layer compound using a heterogeneous pillar insertion reaction. Both the starting 2-D layer and the resulting 3-D open compounds have been characterized using X-ray crystallography.

  435. High-quality as-grown MgB<inf>2</inf> thin-film fabrication at a low temperature using an in-plane-lattice near-matched epitaxial-buffer layer

    O. Sakata, S. Kimura, M. Takata, S. Yata, T. Kato, K. Yamanaka, Y. Yamada, A. Matsushita, S. Kubo

    Journal of Applied Physics 96 (6) 3580-3582 2004年9月15日

    DOI: 10.1063/1.1777805  

    ISSN:0021-8979

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    The fabrication of an as-grown MgB2 crystalline thin film at a low temperature of 270°C was discussed. The fabrication was done using an in-plane-lattice near-matched TiZr buffer layer grown on a sapphire Al 2O3 (0001) surface. The critical temperature and the superconductivity critical current density of MgB2/TiZr/Al 2O3 was found to be higher than the MgB 2/Al2O3. The experiments show that the in-plane-lattice near-matched TiZr buffer layer served for the fabrication of the as-grown MgB2crystalline film.

  436. Distinctive charge density distributions of perovskite-type antiferroelectric oxides PbZrO<inf>3</inf> and PbHfO<inf>3</inf> in cubic phase

    Yoshihiro Kuroiwa, Hiroshi Fujiwara, Akikatsu Sawada, Shinobu Aoyagi, Eiji Nishibori, Makoto Sakata, Masaki Takata, Hitoshi Kawaji, Tooru Atake

    Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 43 (9 B) 6799-6802 2004年9月

    DOI: 10.1143/JJAP.43.6799  

    ISSN:0021-4922

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    The electron charge density distributions of simple perovskite oxides, PbBO3 (B = Ti, Zr and Hf), in their cubic phase are investigated by analyzing high-energy synchrotron powder diffraction data by the maximum entropy method (MEM)/Rietveld method. Clear structural differences between the antiferroelectric and ferroelectric perovskites are revealed. In the cubic phase of PbZrO3 and PbHfO3 that undergo antiferroelectric phase transitions, the Pb atom is disordered around the special Wyckoff position. The thermal motion of the O atom is anisotropic, and the charge density distributions around the O atom are extended in the directions perpendicular to the Zr(Hf)-O3 covalent bond. None of these structural characteristics are observed in the cubic phase of PbTiO3 that undergoes ferroelectric phase transition. The distinctive structural features observed in PbZrO3 and PbHfO3 should provide a clue to the mechanism of antiferroelectric phase transition.

  437. Crystal structure and dielectric and magnetic properties of BiCrO <inf>3</inf> as a ferroelectromagnet

    S. Niitaka, M. Azuma, M. Takano, E. Nishibori, M. Takata, M. Sakata

    Solid State Ionics 172 (1-4 SPEC. ISS.) 557-559 2004年8月31日

    DOI: 10.1016/j.ssi.2004.01.060  

    ISSN:0167-2738

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    We have investigated crystal structure, dielectric and magnetic properties of BiCrO3. The structure of BiCrO3 at room temperature is a highly distorted perovskite-type one with monoclinic C2 symmetry which is the same as that of the ferroelectric phase in BiMnO3. BiCrO3 undergoes a structural phase transition from orthorhombic Pnma with centrosymmetry to monoclinic C2 without centrosymmetry at 440 K. It accompanies a dielectric anomaly, implying a ferroelectric transition. BiCrO3 exhibits a parasitic ferromagnetism at 114 K. © 2004 Elsevier B.V. All rights reserved.

  438. 1-D cobalt(II) spin transition compound with strong interchain interaction: [Co(pyterpy)Cl<inf>2</inf>]·X

    Shinya Hayami, Koichiro Hashiguchi, Gergely Juhász, Masaaki Ohba, Hisashi Okawa, Yonezo Maeda, Kenichi Kato, Kelichi Osaka, Masaki Takata, Katsuya Inoue

    Inorganic Chemistry 43 (14) 4124-4126 2004年7月12日

    DOI: 10.1021/ic049509b  

    ISSN:0020-1669

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    Cobalt(II) compounds [Co(pyterpy)Cl2]·MeOH (1·(MeOH)) and [Co(pyterpy)Cl2]·2H2O (1·(2H2O)) were synthesized. The compound 1·(MeOH) forms the quasi 3-D networks by making π-π stacking between the 1-D chains. The methanol molecules from 1·(MeOH) can be removed by heating, and substituted by absorption of water molecules. The MeOH molecules in 1·(MeOH) are removed by heating at 410 K, and they are substituted by water molecules to form 1·(2H2O). 1·(2H2O) exhibits a S = 3/2 (HS) ⇆ S = 1/2 (LS) spin transition with a thermal hysteresis. We have succeeded in constructing a guest dependent 1-D spin-crossover cobalt(II) compound.

  439. Direct observation of bonding and charge ordering in (EDO-TTF) <inf>2</inf>PF<inf>6</inf>

    Shinobu Aoyagi, Kenichi Kato, Akira Ota, Hideki Yamochi, Gunzi Saito, Hiroyoshi Suematsu, Makoto Sakata, Masaki Takata

    Angewandte Chemie - International Edition 43 (28) 3670-3673 2004年7月12日

    DOI: 10.1002/anie.200454075  

    ISSN:1433-7851

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    Dimers of flat (EDO-TTF)+ molecules separated by bent neutral EDO-TTF (ethylenedioxytetrathiafulvalene) molecules are found in the insulator phase of (EDO-TTF)2PF6, but not in that of the metallic phase. The cooperativity of Peierls distortion, charge ordering, and anion ordering in this metal-insulator transition can be regarded as the result of a molecular displacement.

  440. Dynamical phase transition under photo-excitation in a spin-crossover complex

    Y. Moritomo, Y. Isobe, X. J. Liu, T. Kawamoto, A. Nakamoto, N. Kojima, K. Kato, M. Takata

    Journal of Luminescence 108 (1-4) 229-232 2004年6月

    DOI: 10.1016/j.jlumin.2004.01.049  

    ISSN:0022-2313

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    Temporal evolution of the density, nHS, of photoexcited high-spin (HS) sites in a spin-crossover film (Nafion-[Fe(Htrz)3]; Htrz=1,2,4-4H-triazole) was investigated at 4 K under various excitation power densities, I. We have found that the temporal evolution of nHS slows down when I approaches a critical excitation power density (Ic≈250 mW/cm2). © 2004 Elsevier B.V. All rights reserved.

  441. High-energy x-ray scattering in grazing incidence from nanometer-scale oxide wires

    Osami Sakata, Masaki Takata, Hiroyoshi Suematsu, Akifumi Matsuda, Shusaku Akiba, Atsushi Sasaki, Mamoru Yoshimoto

    Applied Physics Letters 84 (21) 4239-4241 2004年5月24日

    DOI: 10.1063/1.1756207  

    ISSN:0003-6951

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    A method was developed for analyzing the feasibility of rapid x-ray scattering measurement for structure determination of nanowires in air. These crystalline nanowires were deposited on a crystal surfaces. When the x rays were incident perpendicular to the nanowires, the diffraction images pointed down at the direct beam position. The sheet-shape diffraction emanating from ultrathin NiO wires was observed using this method.

  442. Chemical composition and crystal structure of superconducting sodium cobalt oxicle bilayer-hydrate

    Kazunori Takada, Katsutoshi Fukuda, Minoru Osada, Izumi Nakai, Fujio Izumi, Ruben A. Dilanian, Kenichi Kato, Masaki Takata, Hiroya Sakurai, Eiji Takayama-Muromachi, Takayoshi Sasaki

    Journal of Materials Chemistry 14 (9) 1448-1453 2004年5月7日

    DOI: 10.1039/b400181h  

    ISSN:0959-9428

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    Sodium cobalt oxide bilayer-hydrate, NaxCoO2· yH2O (x ≈ 0.35), was characterized by chemical and structure analyses. The formal valence of Co was found to be +3.4 from redox titration, which was much lower than +3.65 that had been estimated from the Na content, x. The deviation from the charge neutralization was considered to be compensated by the presence of oxonium ions in the CoO2 galleries, which was evidenced by Raman spectroscopy. Therefore, the composition of the superconducting phase was determined to be Na0.343(H 3O)0.237CoO2·1.19H2O. Structural studies based on Raman spectroscopy and synchrotron X-ray powder diffraction suggested that the oxonium ions occupy the same crystallographic sites as the Na+ ions.

  443. Anomalous endohedral structure of Gd@C<inf>82</inf> metallofullerenes

    Eiji Nishibori, Kenichi Iwata, Makoto Sakata, Masaki Takata, Hiroshi Tanaka, Haruhito Kato, Hisanori Shinohara

    Physical Review B - Condensed Matter and Materials Physics 69 (11) 2004年3月29日

    DOI: 10.1103/PhysRevB.69.113412  

    ISSN:1098-0121

    eISSN:1550-235X

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    An anomalous endohedral structure of Gd@C82 metallofullerenes has been revealed by synchrotron radiation powder structure analysis by using the maximum entropy method. The Gd@C82 metallofullerene has C82-C2V cage structure as for Sc@C82 and La@C82 fullerenes. The Gd atom is located in the vicinity of the C-C double bond on the C2 molecular axis in the C82/C2V cage, which is the opposite end of the six-membered ring where Sc and La atoms in Sc@C82 and La@C82 are known to be placed. Furthermore, a significant overlap of the electron density distribution has been found between Gd atoms and carbon cages. A significantly polarized distribution of electrons has also been found on the carbon cage around the encapsulated Gd atom. © 2004 The American Physical Society.

  444. Azafullerene (C<sup>59</sup>N)<inf>2</inf> thin-film field-effect transistors

    Ryotaro Kumashiro, Katsumi Tanigaki, Hirotaka Ohashi, Nikos Tagmatarchis, Haruhito Kato, Hisanori Shinohara, Takeshi Akasaka, Kenichi Kato, Shinobu Aoyagi, Shigeru Kimura, Masaki Takata

    Applied Physics Letters 84 (12) 2154-2156 2004年3月22日

    DOI: 10.1063/1.1667013  

    ISSN:0003-6951

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    The fabrication of the azafullerene (C59N)2 thin film field-effect transistors (FET) was presented. The properties of the FET, including electron carrier mobility, were also analyzed. The x-ray diffraction analysis was used for the study. It was observed that the azafullerene FET showed n-channel characteristics with on-off current ratio of 103 and field-effect electron mobility of 3.8×10-4 cm2 V-1 s-1 at room temperature.

  445. Structure analysis of Zn-Mg-Ho icosahedral quasicrystal by modified Rietveld method using ellipsoid and sphere windows

    Tsutomu Ishimasa, Kei Oyamada, Yasuomi Arichika, Eiji Nishibori, Masaki Takata, Makoto Sakata, Kenichi Kato

    Journal of Non-Crystalline Solids 334-335 167-172 2004年3月15日

    DOI: 10.1016/j.jnoncrysol.2003.11.043  

    ISSN:0022-3093

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    A structure analysis of the Zn-Mg-Ho icosahedral quasicrystal was carried out by the powder X-ray diffraction method using synchrotron radiation (λ = 0.73490 Å) at SPring-8. The intensity distribution was analyzed by the Rietveld method modified for an icosahedral quasicrystal, in which simplified models were assumed: ellipsoid and spherical windows were assumed at five crystallographic sites in a F-type hypercubic unit cell. The analysis revealed the presence of an almost perfect Penrose tiling with edge length 5.20 Å. The vertices are occupied alternatively by Zn and Mg, and almost all of the edge centers of the Penrose rhombohedra are occupied by 0.8Zn and 0.2Mg. Ho and Mg atoms tend to be present on the body diagonal of the prolate rhombohedra. Good agreement between the measured and calculated intensity distribution using the simplified model suggests the applicability and the limitation of the structure analysis using the powder X-ray diffraction method. © 2004 Elsevier B.V. All rights reserved.

  446. New technique to measure the polarization dependence of non-resonant X-ray magnetic scattering

    H. Ohsumi, M. Mizumaki, S. Kimura, M. Takata, H. Suematsu

    Physica B: Condensed Matter 345 (1-4) 258-261 2004年3月1日

    DOI: 10.1016/j.physb.2003.11.068  

    ISSN:0921-4526

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    A new technique to measure the polarization dependence of scattering intensity without using an analyzer crystal has been developed and applied to a magnetic satellite reflection of rare-earth metal dysprosium. We have successfully observed the scattering plane inclination angle θ dependence of satellite peak intensity. The magnetic and charge scattering have definitely different θ dependence of scattering intensity, which enables us to distinguish the scattering origins. © 2003 Elsevier B.V. All rights reserved.

  447. Low-glancing-angle x-ray diffraction study on the relationship between crystallinity and properties of C<inf>60</inf> field effect transistor

    Hirotaka Ohashi, Katsumi Tanigaki, Ryotaro Kumashiro, Syuji Sugihara, Shinya Hiroshiba, Shigeru Kimura, Kenichi Kato, Masaki Takata

    Applied Physics Letters 84 (4) 520-522 2004年1月26日

    DOI: 10.1063/1.1638882  

    ISSN:0003-6951

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    The relationship between the structure of C60 thin films and its field effect transistor (FET) properties was investigated. The low glancing angle x-ray diffraction method at a high energy beam facility was used for the study. It was observed that the FET characteristics consisting of C 60 thin films on Si substrates showed little dependence on the structural differences under conventional growth conditions. The trapping levels produced due to the chemical and physical adsorption of oxygen and water were found to influence the FET characteristics.

  448. Quantum Chemical Study on the Configurations of Encapsulated Metal Ions and the Molecular Vibration Modes in Endohedral Dimetallofullerene La <inf>2</inf>@C<inf>80</inf>

    Hidekazu Shimotani, Takayoshi Ito, Yoshihiro Iwasa, Atsushi Taninaka, Hisanori Shinohara, Eiji Nishibori, Masaki Takata, Makoto Sakata

    Journal of the American Chemical Society 126 (1) 364-369 2004年1月14日

    DOI: 10.1021/ja038208i  

    ISSN:0002-7863

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    The configuration of La ions of La2@C80 in the [80]fullerene cage was investigated by use of quantum chemical calculations. We found that the D3d configuration is the global minimum in total energy, being more stable by 1.9 kcal/mol than the D2h configuration, which has been considered to be the most stable. The potential energy surface calculation clarified that La ions travel between 10 equivalent D3d positions through D2h positions and consequently form pentagonal dodecahedral trajectory, which is in good agreement with the previous synchrotron radiation structural study. The experimental and theoretical investigation of the Raman spectrum revealed that the symmetry of molecular vibration is dramatically reduced simply by encapsulation of two La ions, and resulting vibrational modes were successfully assigned. The Raman peak at 163 cm-1 was interpreted as the in-phase synchronously coupled mode of the [80]fullerene cage elongation and the La-La stretching, rather than a conventional and naive assignment as a metal-to-cage vibration mode.

  449. 粉末回折による電子密度レベルでの光励起構造

    加藤 健一, 高田 昌樹, 守友 浩

    日本結晶学会誌 46 10-10 2004年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.46.Supplement_10  

    ISSN:0369-4585

  450. Transport and Magnetic Studies on the Spin State Transition of Pr<inf>1-x</inf>Ca<inf>x</inf>CoO<inf>3</inf> up to High Pressure

    Fujita Toshiaki, Miyashita Takeshi, Yasui Yukio, Kobayashi Yoshiaki, Sato Masatoshi, Nishibori Eiji, Sakata Makoto, Shimojo Yutaka, Igawa Naoki, Ishii Yoshinobu, Kakurai Kazuhisa, Adachi Takafumi, Ohishi Yasuo, Takata Masaki

    Journal of the Physical Society of Japan 73 (7) 1987-1997 2004年

    DOI: 10.1143/JPSJ.73.1987  

    ISSN:0031-9015

    eISSN:1347-4073

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    Transport and magnetic measurements and structural and NMR studies have been carried out on (Pr1-yR/′y)1-xAxCOO3 {R′ = (rare earth elements and Y); A = (Ca, Ba and Sr)} at ambient pressure and high pressure. The system exhibits a phase transition from a nearly metallic to an insulating state with decreasing temperature T, where the low spin (LS) state of Co3+ is suddenly stabilized. For y = 0, we have constructed a T-x phase diagram at various values of the external pressure p. It shows that the (T, x) region of the low temperature phase, which is confined to a very narrow region around x = 0.5 at ambient pressure, expands as p increases. For the occurrence of the transition, both the Pr and Ca atoms seem to be necessary. The intimate relationship between the local structure around the Co ions and the electronic (or spin) state of Co3+ ions is discussed: For the smaller unit cell volume or the smaller volume of the CoO6 octahedra and for the larger tilting angle of the octahedra, the temperature of the transition becomes higher. The role of the carriers introduced by the doping of the A atoms, is also discussed. By analyzing 59Co-NMR spectra and magnetic susceptibility of Pr1-xCaxCoO3, the electronic-energy-separations among the different spin states of Co3+ and Co4+ are roughly estimated. © 2004, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.

  451. Stability of magnesite and its high-pressure form in the lowermost mantle

    Maiko Isshiki, Tetsuo Irifune, Kei Hirose, Shigeaki Ono, Yasuo Ohishi, Tetsu Watanuki, Eiji Nishibori, Masaki Takata, Makoto Sakata

    Nature 427 (6969) 60-63 2004年1月1日

    DOI: 10.1038/nature02181  

    ISSN:0028-0836

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    Carbonates are important constituents of marine sediments and play a fundamental role in the recycling of carbon into the Earth's deep interior via subduction of oceanic crust and sediments. Study of the stability of carbonates under high pressure and temperature is thus important for modelling the carbon budget in the entire Earth system. Such studies, however, have rarely been performed under appropriate lower-mantle conditions and no experimental data exist at pressures greater than 80 GPa (refs 3-6). Here we report an in situ X-ray diffraction study of the stability of magnesite (MgCO3), which is the major component of subducted carbonates, at pressure and temperature conditions approaching those of the core-mantle boundary. We found that magnesite transforms to an unknown form at pressures above ∼115 GPa and temperatures of 2,100-2,200 K (depths of ∼2,600 km) without any dissociation, suggesting that magnesite and its high-pressure form may be the major hosts for carbon throughout most parts of the Earth's lower mantle.

  452. Temperature dependence of structures and order parameters in antiferroelectric PbHfO<inf>3</inf>

    Hideshi Fujishita, Yuya Ishikawa, Akira Ogawaguchi, Kenichi Kato, Eiji Nishibori, Masaki Takata, Makotoo Sakata

    Ferroelectrics 301 139-143 2004年1月1日

    DOI: 10.1080/00150190490455601  

    ISSN:0015-0193

    eISSN:1563-5112

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    Structures of PbHfO3 between 100 K and 500 K were analyzed by Rietveld method using synchrotron radiation. Disordered arrangement of Pb atoms in the cubic phase was found as in PbZrO3. The average of Pb shifts and the square root of lattice distortion showed the similar dependence on temperature as expected from a phenomenological theory.

  453. Studies of capacity losses in cycles and storages for a Li<inf>1.1</inf>Mn<inf>1.9</inf>O<inf>4</inf> positive electrode

    Motoharu Saitoh, Mitsuru Sano, Miho Fujita, Makoto Sakata, Masaki Takata, Eiji Nishibori

    Journal of the Electrochemical Society 151 (1) 2004年

    DOI: 10.1149/1.1630038  

    ISSN:0013-4651

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    A spinel-type of lithium-rich lithium manganese oxide, Li1.1Mn1.9O4, was prepared and studied electrochemically and structurally as a positive electrode of a Li-ion battery. In cycle performance tests, capacity losses were 3 and 11 mAh/g after 75 cycles at 25 and 55°C, respectively, corresponding to 15 and 50 mAh/g for a normal lithium manganese oxide, LiMn2O4. Their losses were divided into two parts; one resulting from the deterioration of the active material itself and the other due to the poor conduction of the active material to the collector. The former and latter contributions to the losses at 55°C were 2 and 9 mAh/g, respectively for the Li-rich spinel, and 18 and 32 mAh/g, respectively for the normal spinel. The capacity loss by the poor conduction was apparently much larger for both spinels of positive electrodes. Cycle performance tests in each region of the charge states divided into five regions show that relatively larger capacity losses were observed in lower potential states. However, in every region, a capacity loss for the Li-rich spinel was much smaller than that of the normal spinel. There was a close relation found between capacity losses in the storage and those in the cycle. Electron densities spreading between manganese and oxygen atoms were larger in the Li-rich than in the normal spinels. Thus, it turned out that the structure of the Li-rich spinel was made more stable because of strong Mn-O bonds.

  454. Recent progress in development of single-component molecular metals

    A. Kobayashi, E. Fujiwara, W. Suzuki, M. Sasa, Y. Fujishiro, E. Nishibori, M. Takata, M. Sakata, Y. Okano, H. Fujiwara, H. Kobayashi

    Journal De Physique. IV : JP 114 419-424 2004年

    DOI: 10.1023/B:EBFI.0000022904.35065.e8  

    ISSN:1155-4339

    eISSN:1764-7177

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    The novel nickel complex with the extended-TTF dithiolate ligand [Ni(tmdt)2] (tmdt=trimethylene dithiotetrathiafulvalenedithiolate) is the first three-dimensional single-component molecular metal with metallic state down to very low temperature (0.6 K). Recently, the direct evidence for presence of electron and hole Fermi surfaces in [Ni(tmdt)2] was obtained by detecting the de Haars-van Alphen (dHvA) effect. We have synthesized analogous single-component molecular conductors with various ligands and central metal atoms and examined their structures and physical properties. The visible and ir spectra of single-component molecular conductors showed that these molecules have unprecedentedly small HOMO-LUMO gaps. © EDP Sciences,.

  455. Direct Observation of Charge Transfer in Double-Perovskite-Like RbMn[Fe(CN)<inf>6</inf>]

    K. Kato, Y. Moritomo, M. Takata, M. Sakata, M. Umekawa, N. Hamada, S. Ohkoshi, H. Tokoro, K. Hashimoto

    Physical Review Letters 91 (25) 2555021-2555024 2003年12月19日

    ISSN:0031-9007

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    The variation of charge density at the Jahn-Teller transition of RbMn[Fe(CN)6] was investigated. The maximum entropy-Rietveld method combined with synchrotron radiation x-ray powder diffraction was used for the study. The origin for the anisotropic bonding electron distribution around the Mn3+ ion in the low-temperature phase was also discussed. The results show a charge transfer from the Mn site to the Fe site in the low-temperature phase.

  456. Structures of a Single-component Palladium Complex with Extended TTF-type Dithiolate Ligands, Bis(tetrathiafulvalenedithiolato)palladium Determined by Powder X-ray Diffraction

    Wakako Suzuki, Emiko Fujiwara, Akiko Kobayashi, Yuichi Fujishiro, Eiji Nishibori, Masaki Takata, Makoto Sakata, Yoshinori Okano, Hayao Kobayashi

    Chemistry Letters 32 (12) 1106-1107 2003年12月5日

    DOI: 10.1246/cl.2003.1106  

    ISSN:0366-7022

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    A new palladium complex with extended-TTF (TTF = tetrathiafulvalene) dithiolate ligands, [Pd(dt)2] (dt = tetrathiafulvalenedithiolate) was prepared and its crystal structure was determined by synchrotron radiation X-ray powder experiments. [Pd(dt)2] is a semiconductor with a room temperature conductivity of 0.3 Scm-1.

  457. Hole-doping and pressure effects on the metal-insulator transition in single crystals of Y<inf>1-x</inf>Ca<inf>x</inf>TiO<inf>3</inf> (0.37 ≤ x ≤ 0.41)

    Masami Tsubota, Fumitoshi Iga, Toshihiro Nakano, Kazuyuki Uchihira, Souichiro Kura, Masaki Takemura, Yoshio Bando, Kazunori Umeo, Toshiro Takabatake, Eiji Nishibori, Masaki Takata, Makoto Sakata, Kenichi Kato, Yasuo Ohishi

    Journal of the Physical Society of Japan 72 (12) 3182-3188 2003年12月

    DOI: 10.1143/JPSJ.72.3182  

    ISSN:0031-9015

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    The measurements of electrical resistivity, magnetic susceptibility, specific heat, thermopower and powder x-ray diffraction under pressure have been performed on single crystals of Y1-xCaxTiO3 (0.37 ≤ x ≤ 0.41) to investigate the hole-doping effect and pressure effect on the metal-insulator (MI) transition. In the low-temperature metallic state, the Ti moment is much reduced from S = 1/2 spin moment in the high-temperature insulating state. Upon applying pressure on the sample with x = 0.37 at temperatures below 200 K, the volume fraction of the orthorhombic phase exceeds that of the monoclinic phase, which is associated with the insulator to metal transition. The good correspondence between the x-T and P-T phase diagrams in the vicinity of the MI transition shows that the effect of hole doping by 1% Ca substitution is equivalent to the effect of application of pressure of 0.41 GPa. The phase separation temperature agrees well with the MI transition temperature, and both temperatures increase linearly with increasing x or pressure. These results indicate that the MI transition in Y 1-xCaxTiO3 is driven by percolation of the low-temperature orthorhombic domains. © 2003 The Physical Society of Japan.

  458. Addenda to "structural transition induced by charge-transfer in RbMn[Fe(CN)<inf>6</inf>]"

    Yutaka Moritomo, Kenichi Kato, Akira Kuriki, Masaki Takata, Makoto Sakata, Hiroko Tokoro, Shin Ichi Ohkoshi, Kazuhito Hashimoto

    Journal of the Physical Society of Japan 72 (10) 2698 2003年10月

    DOI: 10.1143/JPSJ.72.2698  

    ISSN:0031-9015

  459. Charge density measurement in MgH<inf>2</inf> by synchrotron X-ray diffraction

    T. Noritake, S. Towata, M. Aoki, Y. Seno, Y. Hirose, E. Nishibori, M. Takata, M. Sakata

    Journal of Alloys and Compounds 356-357 84-86 2003年8月11日

    DOI: 10.1016/S0925-8388(03)00104-X  

    ISSN:0925-8388

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    Magnesium and its alloys are considered one of the most promising materials for reversible hydrogen storage. However, their high thermodynamic stability is unfavorable for dehydrogenation processes. In order to improve their properties, understanding of the bonding nature of Mg and H is essential. In this study, we reveal the precise experimental charge density distribution in MgH2. X-ray powder diffraction data were obtained using the synchrotron radiation. The charge density distribution was calculated by the MEM (maximum entropy method)/Rietveld analysis. At room temperature, the charge density distribution around Mg is spherical, whereas the lower charge density distribution around H is non-spherical and slightly spread in the direction of the nearest neighbor Mg and H atoms. The number of electrons within the sphere around the Mg and the H atoms were estimated from the obtained distribution. As the result, Mg is almost fully ionized as Mg2+, whereas hydrogen is very weakly ionized. The ionic charge of hydrogen is lower than the theoretical value. © 2003 Elsevier B.V. All rights reserved.

  460. マキシマムエントロピー法による回折データの電子密度イメージング

    高田 昌樹, 坂田 誠

    電子顕微鏡 38 (2) 104-111 2003年7月31日

    出版者・発行元:The Japanese Society of Microscopy

    DOI: 10.11410/kenbikyo1950.38.104  

    ISSN:0417-0326

  461. Structural transformation from single-wall to double-wall carbon nanotube bundles

    Masatoshi Abe, Hiromichi Kataura, Hiroshi Kira, Takeshi Kodama, Shinzo Suzuki, Yohji Achiba, Ken ichi Kato, Masaki Takata, Akihiko Fujiwara, Kazuyuki Matsuda, Yutaka Maniwa

    Physical Review B - Condensed Matter and Materials Physics 68 (4) 2003年7月15日

    DOI: 10.1103/PhysRevB.68.041405  

    ISSN:1098-0121

    eISSN:1550-235X

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    We report an x-ray diffraction (XRD) analysis of the structural transformation from single-wall carbon nanotubes (SWNTs) to double-wall carbon nanotubes (DWNTs) via C60-encapsulating SWNTs (C60 peapods). It was shown that the bundle structure of the starting SWNTs retains on this process. The thermal expansion coefficients of DWNTs hardly changed from the pristine SWNTs. The intertube spacing between inner and outer tubes of DWNTs was obtained as 0.36±0.01 nm. This spacing was shown to be determined by the discreteness of the SWNT diameter under a turbostratic constraint between the inner and outer tubes of DWNT at synthesis temperatures. © 2003 The American Physical Society.

  462. Monoclinic distortion in the insulating phase of PrNiO<inf>3</inf>

    Takashi Saito, Masaki Azuma, Eiji Nishibori, Masaki Takata, Makoto Sakata, Noriaki Nakayama, Takahisa Arima, Tsuyoshi Kimura, Chiharu Urano, Mikio Takano

    Physica B: Condensed Matter 329-333 (II) 866-867 2003年5月

    DOI: 10.1016/S0921-4526(02)02584-X  

    ISSN:0921-4526

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    Single crystals of PrNiO3 perovskite were grown under 4.5 GPa with NaCl and K.Cl flux. The electron diffraction and single crystal synchrotron X-ray diffraction experiments clearly detected the presence of a monoclinic distortion (space group P21/n) below the metal-insulator transition temperature TMI, which implies the splitting of the Ni sites in the crystal in the insulating state. © 2003 Elsevier Science B.V. All rights reserved.

  463. Suppression of a site charge disproportionation in Bi<inf>1-x</inf>La <inf>x</inf>NiO<inf>3</inf>

    Shintaro Ishiwata, Masaki Azuma, Mikio Takano, Eiji Nishibori, Masaki Takata, Makoto Sakata

    Physica B: Condensed Matter 329-333 (II) 813-814 2003年5月

    DOI: 10.1016/S0921-4526(02)02585-1  

    ISSN:0921-4526

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    The effect of the La substitution for Bi in newly found triclinic perovskite BiNiO3 was examined. The charge disproportionation of Bi ions into Bi3+ and Bi5+ was suppressed by 20% substitution. Bi0.8La0.2NiO3 showed a metal-insulator transition at around 300 K. © 2003 Elsevier Science B.V. All rights reserved.

  464. Coherent domain growth under photo-excitation in a Prussian blue analogue

    M. Hanawa, Y. Moritomo, A. Kuriki, J. Tateishi, K. Kato, M. Takata, M. Sakata

    Journal of the Physical Society of Japan 72 (5) 987-990 2003年5月

    DOI: 10.1143/JPSJ.72.987  

    ISSN:0031-9015

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    We have investigated the structural properties of the photo-induced metastable phase of a Prussian blue analogue (Na0.42Co[Fe(CN) 6]0.78·4.64H2O), which shows the photo-magnetization phenomenon, as revealed by means of the high angle-resolved synchrotron-radiation X-ray powder diffraction technique. We have found that (1) the structural domain size is larger than the quenched high-temperature phase and (2) the lattice constant a (= 10.287(1) Å) is larger than that of the quenched phase (a = 10.187(3) Å). These observations indicate that photo-excitation coherently increases the size of the photo-induced metastable region even at low temperature (91 K ≪ Tc). © 2003 The Physical Society of Japan.

  465. Atomic replacement effect on electron charge density of perovskite oxides

    Yoshihiro Kuroiwa, Shinobu Aoyagi, Akikatsu Sawada, Eiji Nishibori, Masaki Takata, Makoto Sakata, Hiroshi Tanaka, Jimpei Harada

    Journal of the Korean Physical Society 42 (SUPPL.) 2003年4月

    ISSN:0374-4884

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    Charge density distributions of cubic SrTiO3 have been investigated related to the atomic replacement effect on the phase transition, by analyzing the synchrotron-radiation X-ray powder-diffraction data by the MEM (Maximum Entropy Method)/Rietveld method. The chemical bonding natures between constituent atoms in cubic SrTiO3 are compared with those in cubic BaTiO3 that we investigated previously at the same temperature. The Characteristic charge density distribution around the O atom, which may present a clue what kind of phase transition occurs in the cubic perovskite oxide, is found in SrTiO3.

  466. Development of single-component molecular metals based on extended-TTF dithiolate ligands

    A. Kobayashi, W. Suzuki, E. Fujiwara, H. Tanaka, Y. Fujishiro, E. Nishibori, M. Takata, M. Sakata, Y. Okanao, H. Kobayashi

    Synthetic Metals 135-136 511-513 2003年4月

    DOI: 10.1016/S0379-6779(02)00703-8  

    ISSN:0379-6779

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    The novel nickel complex with the extended-TTF dithiolate ligand [Ni(tmdt)2] (tmdt2= trimethylenedithiotetrathiafulvalenedithiolate) is the first three-dimensional single-component molecular metal. Structures and physical properties of analogous single-component molecular conductors [Ni(dmdt)2] (dmdt2-=dimethyltetrathiafulvalenedithiolate), [Ni(codt)2] (codt2-=ethylenedioxytetrathiafulvalenedithiolate) and [Pd(C3-tdt)2-] [(C3-tdt)2-= dipropylthiotetrathiafulvalenedithiolate] were examined. The structure of [Au(tmdt)2] was determined by synchrotron radiation powder diffraction experiments and the MEM/Rietveld analysis. The single-component paramagnetic molecule [Cu(dmdt)2] was also studied to clarify the possibility of single-component magnetic molecular conductors. © 2003 Elsevier Science B.V. All rights reserved.

  467. Sc<inf>2</inf> dimer in IPR-violated C<inf>66</inf> fullerene: A covalent bonded metallofullerene

    Masaki Takata, E. Nishibori, M. Sakata, C. R. Wang, H. Shinohara

    Chemical Physics Letters 372 (3-4) 512-518 2003年4月

    DOI: 10.1016/S0009-2614(03)00423-8  

    ISSN:0009-2614

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    The structure of an IPR-violated metallofullerene Sc2Γ 66 has been determined in the electron density level by the MEM/Rietveld method using synchrotron radiation powder data. The fundamental structure has been obtained by the Rietveld analysis. The cage structure of C66 has been unambiguously identified as that of Isomer No. 4348. The obtained charge density by the MEM analysis shows that the encapsulated two Sc atoms form the covalent bonded Sc2 dimer and that the charge density of dimer is overlapping with that of C66 cage, indicating the existence of a covalent bond character between Sc2 and the carbon cage. © 2003 Elsevier Science B.V. All rights reserved.

  468. Charge ordering and spin frustration in AIV<inf>2-×</inf>Cr<inf>×</inf>O<inf>4</inf>

    K. Matsuno, T. Katsufuji, S. Mori, M. Nohara, A. Machida, Y. Moritomo, K. Kato, E. Nishibori, M. Takata, M. Sakata, K. Kitazawa, H. Takagi

    Physical Review Letters 90 (9) 2003年3月7日

    ISSN:0031-9007

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    It was found that the charge-ordered phase of hte AlV2O4 spinel was rapidly suppressed and a charge-disorder phase grows up instead with Cr doping into the V site, yielding a two-phase-coexisting state in modestly Cr-doped samples. The magnetic ground state is a spin-glass state dominated by geometrical frustrtion low temperatures in the charge-ordered phase. Such a difference in magnetic properties can be attributed to the difference in dimensionality as a spin system etween the charge-ordered phase and the charge-disordered phase.

  469. Pressure-induced structural phase transition in fullerides doped with rare-earth metals

    Dam Hieu Chi, Y. Iwasa, K. Uehara, T. Takenobu, T. Ito, T. Mitani, E. Nishibori, M. Takata, M. Sakata, Y. Ohishi, K. Kato, Y. Kubozono

    Physical Review B - Condensed Matter and Materials Physics 67 (9) 2003年3月3日

    DOI: 10.1103/PhysRevB.67.094101  

    ISSN:1098-0121

    eISSN:1550-235X

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    Rare-earth-metal-doped fullerides with nominal composition of (formula presented) (formula presented) Eu) adopt a pseudomonoclinic structure in which (formula presented) dimers glued with rare-earth ions are involved. High-pressure powder x-ray diffraction experiments revealed that these compounds undergo a reversible first-order structural phase transition at 1.5 GPa, associated with 2.7%–2.9% reduction of the unit cell volume. Structural analyses showed that the rare-earth ions, which are located close to the edge of tetrahedral sites at ambient pressure, move back to the center of the tetrahedral sites. Simultaneously, (formula presented) molecules are realigned so that the fivefold (long) axes are perpendicular to the (formula presented) or (formula presented) plane at high pressure. The derived charge density map indicates that the transition is regarded as a structural change from dimers to three-dimensional polymers of fullerenes. These features are ascribed to the unique bonding nature in rare-earth (formula presented) compounds. © 2003 The American Physical Society.

  470. Pressure-induced structural phase transition in fullerides doped with rare-earth metals

    Dam Hieu Chi, Y. Iwasa, Y. Iwasa, Y. Iwasa, K. Uehara, T. Takenobu, T. Takenobu, T. Ito, T. Mitani, E. Nishibori, M. Takata, M. Takata, M. Sakata, Y. Ohishi, K. Kato, Y. Kubozono

    Physical Review B - Condensed Matter and Materials Physics 67 (9) 941011-941019 2003年3月1日

    ISSN:0163-1829

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    Rare-earth-metal-doped fullerides with nominal composition of R3C70 (R= Sm, Eu) adopt a pseudomono-clinic structure in which C70 dimers glued with rare-earth ions are involved. High-pressure powder x-ray diffraction experiments revealed that these compounds undergo a reversible first-order structural phase transition at 1.5 GPa, associated with 2.7%-2.9% reduction of the unit cell volume. Structural analyses showed that the rare-earth ions, which are located close to the edge of tetrahedral sites at ambient pressure, move back to the center of the tetrahedral sites. Simultaneously, C70 molecules are realigned so that the fivefold (long) axes are perpendicular to the (101) or (111)fcc plane at high pressure. The derived charge density map indicates that the transition is regarded as a structural change from dimers to three-dimensional polymers of fullerenes. These features are ascribed to the unique bonding nature in rare-earth C70 compounds.

  471. High-pressure structural analysis of Mn<inf>3</inf>O<inf>4</inf>

    Yutaka Moritomo, Yasuo Ohishi, Akira Kuriki, Eiji Nishibori, Masaki Takata, Makoto Sakata

    Journal of the Physical Society of Japan 72 (3) 765-766 2003年3月

    DOI: 10.1143/JPSJ.72.765  

    ISSN:0031-9015

  472. Highly conducting crystals based on single-component gold complexes with extended-TTF dithiolate ligands

    Wakako Suzuki, Emiko Fujiwara, Akiko Kobayashi, Yuichi Fujishiro, Eiji Nishibori, Masaki Takata, Makoto Sakata, Hideki Fujiwara, Hayao Kobayashi

    Journal of the American Chemical Society 125 (6) 1486-1487 2003年2月12日

    DOI: 10.1021/ja0292243  

    ISSN:0002-7863

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    Highly conducting crystals based on single-component gold complexes with extended-TTF dithiolate ligands [Au(dmdt)2]0+ (1) and [Au(tmdt)2]0+ (2) were prepared (dmdt = dimethyltetrathiafulvalenedithiolate and tmdt = trimethylenetetrathiafulvalenedithiolate). On the basis of the synchrotron radiation powder diffraction data, the MEM electron density of 2 was successfully obtained. The conductivities of compacted powder samples of 1 and 2 at room temperature were 12 and 15 S cm-1, respectively. Pauli-like susceptibility of 1 suggested the system to be essentially metallic at least above 50 K, while 2 showed a magnetic transition around 100 K without loss of its high conductivity. Copyright © 2003 American Chemical Society.

  473. Synchrotron Radiation for Structural Chemistry - Endohedral Natures of Metallofullerenes Found by Synchrotron Radiation Powder Method

    Masaki Takata, Eiji Nishibori, Makoto Sakata, Hisanori Shinohara

    Structural Chemistry 14 (1) 23-38 2003年2月

    DOI: 10.1023/A:1021660824872  

    ISSN:1040-0400

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    The recent progress of the structural studies of endohedral metallofullerenes by the synchrotron radiation (SR) powder diffraction utilizing the maximum entropy method (MEM) is reviewed. Results of the endohedral metallofullerenes (Y@C82, La@C82, Sc@C 82, Sc2@C84, Sc3@C82, Sc2@C66, La2@C80 and Sc 2C2@C84) are given. The precise MEM charge densities of metallofullerenes presents the direct image of endohedral nature of metallofullerenes indicating the charge transfer from metal atoms to carbon cage, which governs the stability of the unique endohedral structures. The MEM/Rietveld method and SR powder method using imaging plate (IP), which are the crucial methods for data analysis and measurement in order to determine structure of fulleride, are also mentioned in some detail.

  474. High pressure synthesis, crystal structure and physical properties of a new Ni(II) perovskite BiNiO3 (vol 12, pg 3733, 2002) 査読有り

    Ishiwata S, Azuma M, Takano M, Nishibori E, Takata M, Sakata M, Kato K

    JOURNAL OF MATERIALS CHEMISTRY 13 (2) 432 2003年

    ISSN:0959-9428

  475. Structures of Novel Nano-Materials Determined by Synchrotron Radiation Powder Experiment:—<I>Atoms in Fullerene Cages & Gas Molecules in Nano-Channel Microporous Compounds</I>—

    Takata Masaki, Sakata Makoto

    日本結晶学会誌 45 10-10 2003年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.45.Supplement_10  

    ISSN:0369-4585

  476. MEMによるSmart Crystallographic Imaging:中性子とX線の相補性

    高田 昌樹, 坂田 誠

    波紋 13 (1) 9-12 2003年

    出版者・発行元:The Japanese Society for Neutron Science

    DOI: 10.5611/hamon.13.9  

    ISSN:1349-046X

  477. C<inf>70</inf> molecular stumbling inside single-walled carbon nanotubes

    Yutaka Maniwa, Hiromichi Kataura, Masatoshi Abe, Akihiko Fujiwara, Ryuji Fujiwara, Hiroshi Kira, Hideki Tou, Shinzo Suzuki, Yohji Achiba, Eiji Nishibori, Masaki Takata, Makoto Sakata, Hiroyoshi Suematsu

    Journal of the Physical Society of Japan 72 (1) 45-48 2003年1月

    DOI: 10.1143/JPSJ.72.45  

    ISSN:0031-9015

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    We report the structural study of C70-one-dimensional (1D) crystal formed inside single-walled carbon nanotubes (SWNTs). X-ray diffraction measurements were performed between 100 K and 999 K on C70- encapsulated SWNTs with an average diameter of 1.37 nm. Two different domains, where the dominant alignment of C70 molecular long axis is standing or lying with respect to the tube axis, were observed; the ratio of the standing to the lying C70-domains is roughly 7 : 3. Thermal expansion of interfullerene distance gave no evidence for orientational phase transitions, not as in the 3D crystals. Instead, the longrange order of the standing C 7o-alignment was thermally destroyed with an activation energy of 39 ± 4 meV. The results imply the importance of either the ID fluctuation or the tube-C70 interaction at finite temperatures. ©2003 The Physical Society of Japan.

  478. Charge Ordering and Spin Frustration in [Formula presented]

    K. Matsuno, T. Katsufuji, S. Mori, M. Nohara, A. Machida, Y. Moritomo, K. Kato, E. Nishibori, M. Takata, M. Sakata, K. Kitazawa, H. Takagi

    Physical Review Letters 90 (9) 4 2003年

    DOI: 10.1103/PhysRevLett.90.096404  

    ISSN:0031-9007

    eISSN:1079-7114

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    The relationship between charge and spin degrees of freedom in a geometrically frustrated system, [Formula presented] spinel, is investigated. Upon Cr doping, the charge-ordered phase of [Formula presented] is rapidly suppressed and a charge-disordered phase grows up instead. It is found that the magnetic ground state is a spin-glass state dominated by geometrical frustration for both phases, but larger spin entropy remains down to low temperatures in the charge-ordered phase, possibly owing to its two-dimensional character. © 2003 The American Physical Society.

  479. Pressure-And photoinduced transformation into a metastable phase in RbMn[Fe(CN)<inf>6</inf>]

    Y. Moritomo, M. Hanawa, Y. Ohishi, K. Kato, M. Takata, A. Kuriki, E. Nishibori, M. Sakata, S. Ohkoshi, H. Tokoro, K. Hashimoto

    Physical Review B - Condensed Matter and Materials Physics 68 (14) 2003年

    DOI: 10.1103/PhysRevB.68.144106  

    ISSN:1098-0121

    eISSN:1550-235X

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    Pressure and photoirradiation effects on the structural properties were investigated for a transition metal cyanide, RbMn[Fe(CN)6], with perovskitelike structure by means of high-angle resolved synchrotron-radiation x-ray powder diffraction. We have found that (1) photoirradiation by a 532-nm pulse laser at 91 K and (2) application of hydrostatic pressure to about 2 GPa at 300 K change the system from the tetragonal low-temperature phase (I4¯m2; Z=2) to a metastable state with different crystal symmetry (P4¯n2; Z=2). We discuss the difference between the photoinduced and pressure-induced processes and suggest possible origin for the photoinduced demagnetization. © 2003 The American Physical Society.

  480. Direct observation of charge transfer in double-perovskite-like [formula presented]

    K. Kato, Y. Moritomo, M. Takata, M. Sakata, M. Umekawa, N. Hamada, S. Ohkoshi, H. Tokoro, K. Hashimoto

    Physical Review Letters 91 (25) 2003年

    DOI: 10.1103/PhysRevLett.91.255502  

    ISSN:0031-9007

    eISSN:1079-7114

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    The charge density distribution has been determined for a transition metal cyanide, [Formula presented], by means of the maximum entropy–Rietveld method combined with the highly angularly resolved synchrotron radiation x-ray powder diffraction at SPring-8 BL02B2. We directly observed a charge transfer from the Mn site to the Fe site in the low-temperature phase. On the basis of a local density approximation calculation, we discuss the origin for the anisotropic bonding electron distribution around the [Formula presented] ion in the low-temperature phase. © 2003 The American Physical Society.

  481. Covalent bonds and their crucial effects on pseudogap formation in α-Al(Mn, Re)Si icosahedral quasicrystalline approximant

    K. Kirihara, T. Nagata, K. Kimura, K. Kato, M. Takata, E. Nishibori, M. Sakata

    Physical Review B - Condensed Matter and Materials Physics 68 (1) 2003年

    DOI: 10.1103/PhysRevB.68.014205  

    ISSN:1098-0121

    eISSN:1550-235X

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    X-ray charge densities of Al-based icosahedral quasicrystalline approximant crystals α-AlReSi, α-AlMnSi, and Al12Re were observed by a combination of the maximum entropy method with the Rietveld method. We successfully obtained the clear images of interatomic covalent bonds between Al and transition metals (Mn, Re) and those in the Al (or Si) icosahedron in Mackay icosahedral clusters of both α-AlReSi and α-AlMnSi approximant crystals. The bonding nature of the three kinds of glue atom sites connecting Mackay icosahedral clusters was also clarified. This covalent bonding nature should strongly relate with the enhancement of the electron density-of-states pseudogap near the Fermi level. In addition, the interatomic covalent bonds of α-AlReSi are stronger than those of α-AlMnSi. This fact leads to the low effective carrier density of α-AlReSi in comparison with that of α-AlMnSi. Unlike the covalent bonding nature of an icosahedron in α-AlReSi and α-AlMnSi crystals, the Al icosahedron with an Re center atom exhibits no Al-Al interatomic covalent bonds in the Al12Re crystal. The tendency for metallic-covalent bonding conversion in the Al icosahedron, which is related to the atom site occupancy of the icosahedral cluster center, is also strongly supported. © 2003 The American Physical Society.

  482. Synchrotron-radiation X-ray powder diffraction study of α- and β-Zn<inf>4</inf>Sb<inf>3</inf> compounds

    T. Souma, G. Nakamoto, M. Kurisu, K. Kato, M. Takata

    International Conference on Thermoelectrics, ICT, Proceedings 2003-January 282-285 2003年

    DOI: 10.1109/ICT.2003.1287504  

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    © 2003 IEEE. The crystal structures of the α- and β-Zn4Sb3 have been investigated by the synchrotron-radiation X-ray powder diffraction at temperatures of 180 to 295 K. The Rietveld analysis indicates that the α-Zn4Sb3 possesses a rhombohedral structure with R-3c as the β-Zn4Sb3 does. The β- to α-phase structural transition is of 2nd order and accompanies the reduction in the c/a and increase in volume (Δa/a>0 and Δc/c<0). The atomic displacement parameters and bond distance are calculated.

  483. Formation of a one-dimensional array of oxygen in a microporous metal-organic solid

    Ryo Kitaura, Susumu Kitagawa, Yoshiki Kubota, Tatsuo C. Kobayashi, Koichi Kindo, Yoshimi Mita, Akira Matsuo, Michihiro Kobayashi, Ho Chol Chang, Tadashi C. Ozawa, Megumi Suzuki, Makoto Sakata, Masaki Takata

    Science 298 (5602) 2358-2361 2002年12月20日

    DOI: 10.1126/science.1078481  

    ISSN:0036-8075

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    We report the direct observation of dioxygen molecules physisorbed in the nanochannels of a microporous copper coordination polymer by the (maximum entropy method)/Rietveld method, using in situ high-resolution synchrotron x-ray powder diffraction measurements. The obtained MEM electron density revealed that van der Waals dimers of physisorbed O2locate in the middle ofnanochannets and form a one-dimensional ladder structure aligned to the host channel structure. The observed O-O stretching Raman band and magnetic susceptibilities are characteristic of the confined O2, molecules in one-dimensional nanochannets of CPL-1 (coordination polymer 1 with pillared layer structure).

  484. High-Pressure Structural Analysis of Fe<inf>3</inf>O<inf>4</inf>

    Akira Kuriki, Yutaka Moritomo, Yasuo Ohishi, Kenichi Kato, Eiji Nishibori, Masaki Takata, Makoto Sakata, Noriaki Hamada, Sakae Todo, Nobuo Mori, Osamu Shimomura, Arao Nakamura

    Journal of the Physical Society of Japan 71 (12) 3092-3093 2002年12月

    DOI: 10.1143/JPSJ.71.3092  

    ISSN:0031-9015

  485. High pressure synthesis, crystal structure and physical properties of a new Ni(II) perovskite BiNiO<inf>3</inf>

    Shintaro Ishiwata, Masaki Azuma, Mikio Takano, Eiji Nishibori, Masaki Takata, Makoto Sakata, Kenichi Kato

    Journal of Materials Chemistry 12 (12) 3733-3737 2002年12月1日

    DOI: 10.1039/b206022a  

    ISSN:0959-9428

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    A new triclinic perovskite, BiNiO3, has been synthesized at a high pressure of 6 GPa in an oxidizing atmosphere. Structure refinements based on synchrotron X-ray powder diffraction and bond-valence calculations revealed a disproportionation of the Bi ions into Bi3+ and Bi5+, both being located in distorted oxygen octahedra. Because of the presence of Bi5+, the oxidation state of Ni was +2, rather than +3 as had been expected; BiNiO3 thus showed insulating behavior with localized spins of S = 1.

  486. Studies of the pressure dependence of the charge density distribution in cerium phosphide by the maximum-entropy method

    Naoki Ishimatsu, Y. Ohishi, M. Takata, E. Nishibori, M. Sakata, J. Hayashi, I. Shirotani, O. Shimomura

    Journal of Physics Condensed Matter 14 (44 SPEC ISS.) 11143-11146 2002年11月11日

    DOI: 10.1088/0953-8984/14/44/441  

    ISSN:0953-8984

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    The physical properties relating of 4f electrons in cerium phosphide, especially the temperature dependence and the isomorphous transition that occurs at around 10 GPa, were studied by means of x-ray powder diffraction and charge density distribution maps derived by the maximum-entropy method. The compressibility of CeP was exactly determined using a helium pressure medium and the anomaly that indicated the isomorphous transition was observed in the compressibility. We also discuss the anisotropic charge density distribution of Ce ions and its temperature dependence.

  487. Structural Analysis of [Fe(ptz)<inf>6</inf>)](BF<inf>4</inf>)<inf>2</inf> under Photo-Excitation - Condensation of Photo-Excited High-Spin Ions

    Yutaka Moritomo, Kenichi Kato, Akira Kuriki, Akio Nakamoto, Norimichi Kojima, Masaki Takata, Makoto Sakata

    Journal of the Physical Society of Japan 71 (11) 2609-2612 2002年11月

    DOI: 10.1143/JPSJ.71.2609  

    ISSN:0031-9015

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    We have performed in situ synchrotron-radiation X-ray powder structural analysis in a spin-crossover complex ([Fe(ptz)6)](BF 4)2: ptz = propyltetrazole) under a photo-excitation with a continuous-wave (CW) green (532nm) laser at 91 K. The Fe2+ ions in the Fe(ptz)6 molecules take the low-spin (LS: S = 0) state at the ground state, and are photo-excited selectively into the high-spin (HS: S = 2) state. When the excitation power P exceeds the critical value, we observed a novel secondary phase which can be ascribed to the condensation of the photo-excited HS ions.

  488. Experimental Observation of Valence Electron Density by Maximum Entropy Method

    Hiroshi Tanaka, Masaki Takata, Makoto Sakata

    Journal of the Physical Society of Japan 71 (11) 2595-2597 2002年11月

    DOI: 10.1143/JPSJ.71.2595  

    ISSN:0031-9015

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    A simple scheme is introduced which extracts the valence electron density from X-ray diffraction data by employing the maximum entropy method. It is applied to silicon, and reveals in detail the bonding nature. A spool-shaped charge distribution is observed between Si atoms corresponding to the bond, and the charge density along the bonding direction has a two-peak structure. Furthermore, concentric sphere-shaped reduction in charge density is observed around the nuclei, which corresponds to the nodes in wavefunctions. These features agree quantitatively with those obtained by first principles calculation.

  489. Anomalous Spin Density Distribution in CeB<inf>6</inf>

    Masahiro Saitoh, Noriko Okada, Eiji Nishibori, Hiroyuki Takagiwa, Tetsuya Yokoo, Masakazu Nishi, Kazuhisa Kakurai, Satoru Kunii, Masaki Takata, Makoto Sakata, Jun Akimitsu

    Journal of the Physical Society of Japan 71 (10) 2369-2372 2002年10月

    DOI: 10.1143/JPSJ.71.2369  

    ISSN:0031-9015

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    Here, we present, for the first time, the spin density distribution of CeB6, isostructural with CaB6, deduced by the maximum entropy method (MEM) using polarized neutron diffraction (PND) data. Surprisingly, it reveals the presence of significant amounts of localized spin moment at non atomic sites between the nearest-neighbor boron atoms and the center of the triangle surface in the B6 octahedron network, in addition to the negative spin moment in the center of the B6 octahedron.

  490. Crystal structure and magnetic properties of hexagonal RMnO<inf>3</inf> (R = Y, Lu, and Sc) and the effect of doping

    T. Katsufuji, M. Masaki, A. Machida, M. Moritomo, K. Kato, E. Nishibori, M. Takata, M. Sakata, K. Ohoyama, K. Kitazawa, H. Takagi

    Physical Review B - Condensed Matter and Materials Physics 66 (13) 1344341-1344348 2002年10月1日

    ISSN:0163-1829

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    A ferroelectricity-magnetism-coexisting system, hexagonal RMnO3 (R = Y, Lu, and Sc), has been investigated by synchrotron x-ray and neutron powder diffraction measurements. It is found from x-ray diffraction measurements that the ferroelectric polarization originates from the tilting of MnO5 polyhedra and the buckling of R layers, which persists up to 1000 K. Neutron diffraction measurements have revealed the reduction of ordered moments from the expected value, as well as strong magnetic diffuse scattering existing far above TN, both of which are caused by geometrical frustration of the triangular lattice of Mn ions. We have also investigated the effects of Zr doping into the R site and have found that Zr doping drastically suppresses both ferroelectric distortion and magnetic ordering.

  491. Orbital hybridization and covalency in paraelectric and ferroelectric SrBi<inf>2</inf>Nb<inf>2</inf>O<inf>9</inf>

    Y. Shimakawa, H. Imai, H. Kimura, S. Kimura, Y. Kubo, E. Nishibori, M. Takata, M. Sakata, K. Kato, Z. Hiroi

    Physical Review B - Condensed Matter and Materials Physics 66 (14) 1441101-1441105 2002年10月1日

    ISSN:0163-1829

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    Electron-density distributions of paraelectric and ferroelectric SrBi2Nb2O9 were analyzed by means of synchrotron x-ray diffraction. The obtained electron-density distributions well reproduced the atomic arrangements of the material. Bonding electrons due to hybridization of orbitals were clearly seen in the Nb-O bonds in the octahedron and in the Bi-O bonds in the Bi2O2 layer. The hybridization between Nb(4d) and O(2p) orbitals was enhanced in the ferroelectric phase, and one of the Nb-O bonds showed a strong covalent character below the ferroelectric Curie temperature. Weak hybridization of the Sr(5s) with O(2p) orbitals appears to play an important role in structural distortion and ferroelectric polarization. The changes in the electron-density distribution through the ferroelectric phase transition are similar to those observed in ferroelectric PbTiO3 perovskite.

  492. Direct Observation of Covalency between O and Disordered Pb in Cubic PbZrO<inf>3</inf>

    Shinobu Aoyagi, Yoshihiro Kuroiwa, Akikatsu Sawada, Hiroshi Tanaka, Jimpei Harada, Eiji Nishibori, Masaki Takata, Makoto Sakata

    Journal of the Physical Society of Japan 71 (10) 2353-2356 2002年10月

    DOI: 10.1143/JPSJ.71.2353  

    ISSN:0031-9015

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    In cubic PbZrO3, which undergoes an antiferroelectric phase transition, the distinct disorder of Pb at twelve sites toward the neighboring O is detected for the first time by analyzing high-energy X-ray powder diffraction data. In the charge density distributions, the covalent nature of the Pb-O bond is also revealed, which proves the existence of electron hybridization between O and disordered Pb in cubic PbZrO3. None of these structural characteristics of PbZrO3 were found in the previously studied cubic PbTiO3 structure [Y. Kuroiwa et al.: Phys. Rev. Lett. 87 (2001) 217601], which undergoes a ferroelectric phase transition. This may be a clue to understanding why PbTiO3 and PbZrO3 respectively show ferroelectric and antiferroelectric phase transitions.

  493. Chemical bonding of hydrogen in MgH<inf>2</inf>

    T. Noritake, M. Aoki, S. Towata, Y. Seno, Y. Hirose, E. Nishibori, M. Takata, M. Sakata

    Applied Physics Letters 81 (11) 2008-2010 2002年9月9日

    DOI: 10.1063/1.1506007  

    ISSN:0003-6951

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    MgH2 is one of the promising base materials for hydrogen storage, which is a key technology of clean energy source. In this study, the bonding nature of hydrogen in MgH2 was fully uncovered by examining the charge density distribution of this substance obtained by the maximum entropy method from the synchrotron radiation powder data. MgH2 can be expressed as Mg1.91+ H0.26-, which is much weaker ionicity than the theoretical expectations. It also shows weak covalence between Mg and H. Though the bonding nature of hydrogen in MgH2 is rather complex, i.e., the mixture of ionic and covalent bonding, it is certain that hydrogen is weakly bonded to Mg, which must be a big advantage of hydrogenation-dehydrogenation of this substance. © 2002 American Institute of Physics.

  494. The Metal-Insulator Transition in Y<inf>1-x</inf>Ca<inf>x</inf>TiO <inf>3</inf> Caused by Phase Separation

    K. Kato, E. Nishibori, M. Takata, M. Sakata, T. Nakano, K. Uchihira, M. Tsubota, F. Iga, T. Takabatake

    Journal of the Physical Society of Japan 71 (9) 2082-2085 2002年9月

    DOI: 10.1143/JPSJ.71.2082  

    ISSN:0031-9015

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    In order to explore the origin of the metal-insulator (M-I) transition, the precise crystal structures of the hole-doped Mott insulator system, Y 1-xCaxTiO3 (x = 0.37, 0.39 and 0.41), are studied for the temperature range between 20 K and 300 K by synchrotron radiation (SR) X-ray powder diffraction. For both Y0.63Ca 0.37TiO3 and Y0.61Ca0.39TiO 3 compositions, the orthorhombic (Pbnm) - monoclinic (P2 1/n) structural phase transition occurs at approximately 230 K, which is much higher than their individual M-I transition temperatures, i.e., 60 K and 130 K, respectively. For these compositions, significant phase separation (low-temperature orthorhombic + monoclinic) is also found in the vicinity of the M-I transition temperature. On the other hand, Y 0.59Ca0.41TiO3, which does not exhibit M-I transition and preserves a metallic behavior down to 1.5 K, is in a two phase state from 20 K to 300 K. It is concluded that the existence of the phase separation causes the M-I transition in Y1-xCaxTiO 3, and the low-temperature orthorhombic phase contributes to the metallic property of this system.

  495. Structural Transition Induced by Charge-Transfer in RbMn[Fe(CN) <inf>6</inf>] - Investigation by Synchrotron-Radiation X-ray Powder Analysis

    Yutaka Moritomo, Kenichi Kato, Akira Kuriki, Masaki Takata, Makoto Sakata, Hiroko Tokoro, Shin Ichi Ohkoshi, Kazuhito Hashimoto

    Journal of the Physical Society of Japan 71 (9) 2078-2081 2002年9月

    DOI: 10.1143/JPSJ.71.2078  

    ISSN:0031-9015

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    Temperature dependence of atomic coordinates is determined for RbMn[Fe(CN)6] by means of synchrotron-radiation (SR) X-ray powder structural analysis. We observed a structural transition from the cubic (F4̄3m; Z = 4) to the tetragonal (I4̄m2; Z = 2) phase at ≈210 K in the cooling run and at ≈300 K in the warming run. In the low-temperature tetragonal phase, we found Jahn-Tellar type distortion of the MnN6 octahedra and compression of the averaged Fe-C bond distance. These structural data suggest that the structural transition is triggered by the inter-metallic charge-transfer from the Mn(II) site to the Fe(III) site.

  496. Bridging fullerenes with metals

    Dam Hieu Chi, Y. Iwasa, X. H. Chen, T. Takenobu, T. Ito, T. Mitani, E. Nishibori, M. Takata, M. Sakata, Y. Kubozono

    Chemical Physics Letters 359 (3-4) 177-183 2002年6月20日

    DOI: 10.1016/S0009-2614(02)00297-X  

    ISSN:0009-2614

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    The bonding nature between rare earth metals and fullerene molecules has been investigated. The electron density distribution for nominal Sm3C70, calculated by a maximum entropy method (MEM) based on the Rietveld analysis of synchrotron X-ray diffraction pattern, unambiguously demonstrated a covalent Sm-C bond, which is almost as strong as the interatomic bonding of crystal Si. Furthermore, the Sm bridges two C70 molecules, producing a C70-Sm-C70 dimer structure. © 2002 Elsevier Science B.V. All rights reserved.

  497. Low-Temperature Structure of [Fe(ptz)<inf>6</inf>](BF<inf>4</inf>) <inf>2</inf> - Determination by Synchrotron-Radiation X-ray Powder Study

    Yutaka Moritomo, Kenichi Kato, Akio Nakamoto, Norimichi Kojima, Eiji Nishibori, Masaki Takata, Makoto Sakata

    Journal of the Physical Society of Japan 71 (4) 1015-1018 2002年4月

    DOI: 10.1143/JPSJ.71.1015  

    ISSN:0031-9015

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    Temperature dependence of atomic coordinates is precisely determined for an iron (II) complex, [Fe(ptz)6](BF4)2 (ptz = propyltetrazole), by means of synchrotron-radiation (SR) x-ray powder diffraction measurements. The spin state of the Fe2+ ions is known to change from high-spin (HS; S = 2) to low-spin (LS; S = 0) with a decrease in temperature to below Tc ≈ 130 K. We have found that the spin state transition accompanies a significant contraction of the Fe-N4 bond distance from ≈2.20 Å (HS) to ≈2.00 Å (LS).

  498. High-pressure structural analysis of (Nd, Sm)<inf>1/2</inf>Sr<inf>1/2</inf>MnO<inf>3</inf>: Origin for pressure-induced charge ordering

    A. Kuriki, Y. Moritomo, A. Machida, E. Nishibori, M. Takata, M. Sakata, Y. Ohishi, O. Shimomura, A. Nakamura

    Physical Review B - Condensed Matter and Materials Physics 65 (11) 1131051-1131054 2002年3月15日

    ISSN:0163-1829

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    Pressure effects on the structural parameters are investigated in a half-doped manganites (Nd0.125Sm0.875)1/2Sr1/2 MnO3, by means of the synchrotron-radiation x-ray powder diffraction measurement. The compound shows a pressure-induced metal-insulator transition due to the subtle competition between the double-exchange interaction and the charge-ordering instability [Y. Tokura et al., Phys. Rev. Lett. 76, 3184 (1996)]. We have found that application of pressure induces the four-long and two-short deformation of the MnO6 octahedra. We present a possible scenario for the pressure-induced charge-ordering.

  499. 8aSH-7 SrBi2Nb2O9強誘電体の電荷密度分布(誘電体,領域10)

    島川 祐一, 今井 英人, 木村 英和, 木村 滋, 久保 佳実, 西堀 英治, 高田 昌樹, 坂田 誠, 加藤 健一

    日本物理学会講演概要集 57.2.4 817 2002年

    出版者・発行元:一般社団法人 日本物理学会

    DOI: 10.11316/jpsgaiyo.57.2.4.0_817_2  

    eISSN:2189-0803

  500. X線回折(I)

    高田 昌樹

    応用物理 71 (3) 343-347 2002年

    出版者・発行元:The Japan Society of Applied Physics

    DOI: 10.11470/oubutsu1932.71.343  

    ISSN:0369-8009

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    X線回折の基礎について,X線の発生,電子によるX線の散乱に始まり,結晶によるX線の回折,X線結晶構造解析の原理を平易に解説する.

  501. X線回折 (II)

    高田 昌樹

    応用物理 71 (4) 453-458 2002年

    出版者・発行元:The Japan Society of Applied Physics

    DOI: 10.11470/oubutsu1932.71.453  

    ISSN:0369-8009

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    結晶表面からのX線回折について,結晶表面に垂直な方向に伸びる棒状の散乱, OTR散乱 (Orystai Truncation Rod Scattering) を中心に説明する.そして, CTR散乱による結晶表面および界面の原子レベルでの評価法について,その基本原理を解説する.

  502. Where is the magnetic moment in CeB<inf>6</inf>?

    Masahiro Saitoh, Hiroyuki Takagiwa, Hirohiko Ichikawa, Tetsuya Yokoo, Jun Akimitsu, Masakazu Nishi, Kazuhisa Kakurai, Masaki Takata, Noriko Okada, Makoto Sakata, Satoru Kunii

    Journal of the Physical Society of Japan 71 (SUPPL.) 106-108 2002年

    DOI: 10.1143/jpsjs.71s.106  

    ISSN:0031-9015

    eISSN:1347-4073

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    We performed the polarized neutron diffraction measurements in phase II of CeB6 to observe the magnetic form factors. By the Maximum Entropy Method (MEM), we obtained the unexpected spin density distribution in CeB 6. We clearly observed the existence not only at Ce site but also at between B6 octahedral and at the center of triangle bonding ]in the B6 octahedral. This is the first evidence that the magnetic moments are located between the Borons. © 2002 The Physical Society of Japan.

  503. Crystal structure and magnetic properties of hexagonal (formula presented) Lu, and Sc) and the effect of doping

    T. Katsufuji, M. Masaki, A. Machida, M. Moritomo, K. Kato, E. Nishibori, M. Takata, M. Sakata, K. Ohoyama, K. Kitazawa, H. Takagi

    Physical Review B - Condensed Matter and Materials Physics 66 (13) 1-8 2002年

    DOI: 10.1103/PhysRevB.66.134434  

    ISSN:1098-0121

    eISSN:1550-235X

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    A ferroelectricity-magnetism-coexisting system, hexagonal (formula presented) Lu, and Sc), has been investigated by synchrotron x-ray and neutron powder diffraction measurements. It is found from x-ray diffraction measurements that the ferroelectric polarization originates from the tilting of (formula presented) polyhedra and the buckling of R layers, which persists up to 1000 K. Neutron diffraction measurements have revealed the reduction of ordered moments from the expected value, as well as strong magnetic diffuse scattering existing far above (formula presented) both of which are caused by geometrical frustration of the triangular lattice of Mn ions. We have also investigated the effects of Zr doping into the R site and have found that Zr doping drastically suppresses both ferroelectric distortion and magnetic ordering. © 2002 The American Physical Society.

  504. Microscopic Charge Separation in Tb<inf>1-x</inf>Ca<inf>x</inf>MnO <inf>3</inf> (x ∼ 1)

    Akihiko Machida, Yutaka Moritomo, Shigeo Mori, Naoki Yamamoto, Kenji Ohoyama, Eiji Nishibori, Masaki Takata, Makoto Sakata, Toshiya Otomo, Arao Nakamura

    Journal of the Physical Society of Japan 71 (1) 27-30 2002年1月

    DOI: 10.1143/JPSJ.71.27  

    ISSN:0031-9015

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    Microscopic magnetic structures of Tb1-xCaxMnO 3 (x ∼ 1) have been investigated by means of small-angle neutron scattering (SANS) and Lorentz micrograph experiments. We have found that ferromagnetic microclusters of the order of ∼10 nm are invaded in the antiferromagnetic matrix with the G-type spin structure. We have interpreted the coexistence of the magnetic clusters in terms of intrinsic change separation.

  505. Orbital hybridization and covalency in paraelectric and ferroelectric (formula presented)

    Y. Shimakawa, H. Imai, H. Kimura, S. Kimura, Y. Kubo, E. Nishibori, M. Takata, M. Sakata, K. Kato, Z. Hiroi

    Physical Review B - Condensed Matter and Materials Physics 66 (14) 1-5 2002年

    DOI: 10.1103/PhysRevB.66.144110  

    ISSN:1098-0121

    eISSN:1550-235X

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    Electron-density distributions of paraelectric and ferroelectric (formula presented) were analyzed by means of synchrotron x-ray diffraction. The obtained electron-density distributions well reproduced the atomic arrangements of the material. Bonding electrons due to hybridization of orbitals were clearly seen in the Nb-O bonds in the octahedron and in the Bi-O bonds in the (formula presented) layer. The hybridization between (formula presented) and (formula presented) orbitals was enhanced in the ferroelectric phase, and one of the Nb-O bonds showed a strong covalent character below the ferroelectric Curie temperature. Weak hybridization of the (formula presented) with (formula presented) orbitals appears to play an important role in structural distortion and ferroelectric polarization. The changes in the electron-density distribution through the ferroelectric phase transition are similar to those observed in ferroelectric (formula presented) perovskite. © 2002 The American Physical Society.

  506. High-pressure structural analysis of (formula presented) Origin for pressure-induced charge ordering

    A. Kuriki, Y. Moritomo, A. Machida, E. Nishibori, M. Takata, M. Sakata, Y. Ohishi, O. Shimomura, A. Nakamura

    Physical Review B - Condensed Matter and Materials Physics 65 (11) 1-4 2002年

    DOI: 10.1103/PhysRevB.65.113105  

    ISSN:1098-0121

    eISSN:1550-235X

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    Pressure effects on the structural parameters are investigated in a half-doped manganites (formula presented) by means of the synchrotron-radiation x-ray powder diffraction measurement. The compound shows a pressure-induced metal-insulator transition due to the subtle competition between the double-exchange interaction and the charge-ordering instability [Y. Tokura et al., Phys. Rev. Lett. 76, 3184 (1996)]. We have found that application of pressure induces the four-long and two-short deformation of the (formula presented) octahedra. We present a possible scenario for the pressure-induced charge-ordering. © 2002 The American Physical Society.

  507. Accurate charge-densities of crystalline materials obtained by third generation SR and MEM/rietveld analysis

    Yoshihiro Kuroiwa, Shinobu Aoyagi, Akikatsu Sawada, Eiji Nishibori, Masaki Takata, Makoto Sakata, Hiroshi Tanaka, Jimpei Harada

    Ferroelectrics 268 23-28 2002年1月1日

    DOI: 10.1080/713716011  

    ISSN:0015-0193

    eISSN:1563-5112

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    The advent of third-generation synchrotron-radiation (SR) provides a new opportunity of the supreme powder diffractometry, which allows one to determine accurate charge-densities, when the collected data are analyzed by the MEM/Rietveld method. The Large Debye-Scherrer Camera with an Imaging Plate as a detector has been designed and installed at BL02B2 in SPring-8 for the charge-density study. We have succeeded in observing the significant electron-orbital hybridizations revealed in the bonding electron distributions of PbTiO 3 and BaTiO 3 , which are closely related to the ferroelectric properties. © 2002 Taylor and Francis.

  508. Precise charge density analysis of PbTiO<inf>3</inf>

    Shinobu Aoyagi, Yoshihiro Kuroiwa, Akikatsu Sawada, Eiji Nishibori, Masaki Takata, Makoto Sakata, Hiroshi Tanaka, Jimpei Harada

    Ferroelectrics 269 303-308 2002年1月1日

    DOI: 10.1080/713716015  

    ISSN:0015-0193

    eISSN:1563-5112

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    Precise charge-density distributions of cubic and tetragonal PbTiO 3 have been investigated associated with the ferroelectric phase transition at 763K, by means of the MEM/Rietveld analysis using synchrotron radiation X-ray powder-diffraction data. It has been clearly visualized that cubic PbTiO 3 consists of the three-dimensional covalent network of TiO 6 octahedra and isolated Pb 2+ ions, whereas tetragonal PbTiO 3 forms a layered structure with the two-dimensional covalent network of TiO 5 pyramids, to which Pb atoms are also covalently bonded. These findings on the binding nature of tetragonal PbTiO 3 give good agreement with theoretical predictions by the first-principles calculations. © 2002 Taylor and Francis.

  509. Charge density level structures of endohedral metallofullerenes determined by synchrotron radiation powder method

    Masaki Takata, Eiji Nishibori, Makoto Sakata, Hisanori Shinohara

    New Diamond and Frontier Carbon Technology 12 (5) 271-286 2002年

    ISSN:1344-9931

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    The recent X-ray structural studies of endohedral metallofullerenes by synchrotron radiation (SR) powder diffraction utilizing the maximum entropy method (MEM) are reviewed. Results for endohedral metallofullerenes (Y@C82, La@C82, Sc@C82, Sc2@C84, Sc3@C82, Sc2@C66, La2@C80 and Sc2C2@C84) are given. The precise MEM charge densities of metallofullerenes present direct images of the endohedral nature of metallofullerenes and reveal the features of the charge transfer from metal atoms to a carbon cage, which governs the stability of the unique endohedral structures. The MEM/Rietveld method, which is the crucial method for structural determination of endohedral metallofullerenes based on SR powder data, is also described in some detail.

  510. ENIGMA: Maximum-entropy method program package for huge systems

    Hiroshi Tanaka, Masaki Takata, Eiji Nishibori, Kenichi Kato, Takashi Iishi, Makoto Sakata

    Journal of Applied Crystallography 35 (2) 282-286 2002年

    DOI: 10.1107/S002188980200050X  

    ISSN:0021-8898

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    ENIGMA (Electron and Nuclear Image Generator by Max-ent Analysis) is a program package to evaluate three-dimensional electron and nuclear density from X-ray and neutron diffraction data by using the maximum-entropy method (MEM). Compared with the previous program package MEED, ENIGMA saves computing time and frees memory space at the same time by employing parallel data processing. The fast Fourier transformation (FFT) technique is also implemented. As a consequence of these improvements, the MEM analysis by ENIGMA becomes applicable to huge systems, such as proteins and polymers, when the phased structure factors are provided. The package is transferable to a wide variety of parallel computers, because it is written in Fortran 90 and a standard message-passing interface (MPI). © 2002 International Union of Crystallography Printed in Great Britain - all rights reserved.

  511. Thermal expansion of single-walled carbon nanotube (SWNT) bundles: X-ray diffraction studies

    Yutaka Maniwa, Ryuji Fujiwara, Hiroshi Kira, Hideki Tou, Hiromichi Kataura, Shinzo Suzuki, Yohji Achiba, Eiji Nishibori, Masaki Takata, Makoto Sakata, Akihiko Fujiwara, Hiroyoshi Suematsu

    Physical Review B - Condensed Matter and Materials Physics 64 (24) 2414021-2414023 2001年12月15日

    ISSN:0163-1829

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    Thermal expansion coefficient in single-walled carbon nanotube bundles was determined as (-0.15±0.20) × 10-5 (1/K) for the tube diameter and (0.75±0.25) × 10-5 (1/K) for the triangular lattice constant by means of x-ray scattering between 300 K to 950 K. The value for the intertube gap was (4.2±1.4) × 10-5 (1/K), which is larger than 2.6×10-5 (1/K) for the c-axis thermal expansion in graphite. The results reveal the presence of a remarkably larger lattice anharmonicity in nanotube bundles than that of graphite. The small value for the tube diameter is consistent with the seamless tube structure formed by a strong covalent bond between carbon atoms comparable to that in graphite.

  512. The large Debye-Scherrer camera installed at SPring-8 BL02B2 for charge density studies

    E. Nishibori, M. Takata, K. Kato, M. Sakata, Y. Kubota, S. Aoyagi, Y. Kuroiwa, M. Yamakata, N. Ikeda

    Journal of Physics and Chemistry of Solids 62 (12) 2095-2098 2001年12月

    DOI: 10.1016/S0022-3697(01)00164-0  

    ISSN:0022-3697

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    The design and performance of a large Debye-Scherrer Camera with Imaging Plate (IP) as detectors, which was very recently installed at SPring-8, BL02B2, is reported. By taking advantage of high beam quality of SPring-8, the camera enables a rapid collection of a high counting statistics and high angular resolution powder pattern, which should be suitable for charge density studies by powder specimens. The camera also provides easy access to investigation of structural changes at varied temperatures between 15-1000 K. The camera provides an advanced powder diffraction system utilizing third generation SR, i.e. rapid and accurate. © 2001 Elsevier Science Ltd. All rights reserved.

  513. Structural Change at Metal-Insulator Transition of Tb<inf>2</inf>Ba<inf>2</inf>Co<inf>4</inf>O<inf>11</inf>

    Hiroyuki Kusuya, Akihiko Machida, Yutaka Moritomo, Kenichi Kato, Eiji Nishibori, Masaki Takata, Makoto Sakata, Arao Nakamura

    Journal of the Physical Society of Japan 70 (12) 3577-3580 2001年12月

    DOI: 10.1143/JPSJ.70.3577  

    ISSN:0031-9015

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    Temperature variation of the crystal structure has been investigated for Tb2Ba2CO4O11, which shows a metal-insulator (MI) transition at TMI = 340 K. The compound has a layered-type double-perovskite structure along the c-axis, with alternating the CoO6 octahedron and the CoO5 pyramids along the a-axis. With decrease of temperature below TMI, the distortion of the octahedral and pyramidal sites is fairly released, suggesting that spin state transition of the Co3+ ions is the origin for the MI transition.

  514. Enhanced specific heat jump in electron-doped CaMnO<inf>3</inf>: Spin ordering driven by charge separation

    Y. Moritomo, A. Machida, E. Nishibori, M. Takata, M. Sakata

    Physical Review B - Condensed Matter and Materials Physics 64 (21) 2144091-2144095 2001年12月1日

    ISSN:0163-1829

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    Temperature variation of the magnetic susceptibility χ, resistivity ρ, specific heat C, and lattice constants has been investigated in electron-doped CaMnO3. The parent CaMnO3 is an antiferromagnetic band insulator, and shows an insulator-metal crossover with electron doping, together with an enhanced ferromagnetic component. We have found an enhancement of the specific heat jump AC at the spin-ordering temperature Tspin and interpreted the enhancement in terms of the intrinsic charge separation.

  515. Evidence for Pb-O covalency in tetragonal PbTiO<inf>3</inf>

    Yoshihiro Kuroiwa, Shinobu Aoyagi, Akikatsu Sawada, Jimpei Harada, Eiji Nishibori, Masaki Takata, Makoto Sakata

    Physical Review Letters 87 (21) 2176011-2176014 2001年11月19日

    DOI: 10.1103/PhysRevLett.87.217601  

    ISSN:0031-9007

    eISSN:1079-7114

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    An experimental evidence for the Pb-O hybridization was reported as Pb-O covalent bonding electron distribution in the charge density distribution of tetragonal PbTiO3. A high energy synchrotron X-ray powder diffraction data was collected for the analysis of the compounds during the study. Maximum entropy method (MEM)/Rietveld technique was used to determine the electron density distributions. The results indicated the existence of strong covalency in the tetragonal compound as compared to that having a cubic structure. The tertragonal PbTiO3 was found to form a layered structure of a two-dimensional covalent-bonding network consisting of the Ti-O5 pyramid.

  516. Dimer structure of Sm<inf>3</inf>C<inf>70</inf>

    Hieu Chi Dam, X. H. Chen, T. Takenobu, T. Itou, Y. Iwasa, T. Mitani, E. Nishibori, M. Takata, M. Sakata

    AIP Conference Proceedings 590 447-450 2001年10月16日

    DOI: 10.1063/1.1420148  

    ISSN:0094-243X

    eISSN:1551-7616

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    © 2001 American Institute of Physics. A single phase of rare earth doped C70 compounds, Sm3C70, has been first isolated. The Rietveld analysis of the synchrotron x-ray diffraction pattern of the nominal Sm3C70 revealed that there exist extremely short Sm-C bonds. The short bonds are arranged so as to form a C70-Sm-C70 dimer structure. The experiments of the high temperature x-ray diffraction show that this structure is maintained up to 850K, indicating that the bonds are extremely stable comparing to the conventional interfullerene bonds.

  517. Structure of IPR-violated fullerene, Sc<inf>2</inf>@C<inf>66</inf>

    E. Nishibori, M. Takata, M. Sakata, Chun Ru Wang, M. Inakuma, H. Shinohara

    AIP Conference Proceedings 590 461-464 2001年10月16日

    DOI: 10.1063/1.1420151  

    ISSN:0094-243X

    eISSN:1551-7616

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    © 2001 American Institute of Physics. The endohedral structure of Isolated Pentagon Rule(IPR) violated scandium metallofullerene Sc2@C66 is determined by the maximum entropy method (MEM) combined with the Rietveld method using synchrotron radiation powder data. The result reveals for the assistance of the fused pentagon first time. The fused pentagon locates close to the encapsulated Sc-dimmers. The Charge state of the encaged dimmer is also determined Sc22+@C662- form the MEM charge density. The Sc-Sc distance in Sc2 cluster is 2.87(9) Å.

  518. Fe-site substitution effects on conductive ferromagnet Sr2FeMoO6

    Y. Moritomo, H. Kuzuya, A. Machida, E. Nishibori, M. Takata, M. Sakata, A. Nakamura

    Journal of the Physical Society of Japan 70 (10) 3182-3183 2001年10月

    DOI: 10.1143/JPSJ.70.3182  

    ISSN:0031-9015

  519. Phase inhomogeneities and lattice expansion near T<inf>c</inf> in the Mg<sup>11</sup>B<inf>2</inf> superconductor

    S. Margadonna, T. Muranaka, K. Prassides, I. Maurin, K. Brigatti, R. M. Ibberson, M. Arai, M. Takata, J. Akimitsu

    Journal of Physics Condensed Matter 13 (35) 2001年9月3日

    DOI: 10.1088/0953-8984/13/35/101  

    ISSN:0953-8984

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    High-resolution powder neutron diffraction has been used to study the crystal structure of the Mg11B2 superconductor (Tc = 39.2 K) prepared at high pressure in the temperature range 2 to 293 K. The experimental data provide clear evidence of temperature-independent phase inhomogeneity, which was modelled by coexisting Mg1+δB2 phases. Precise structural information for temperatures near Tc also reveals extremely small volume and c-axis discontinuities, consistent with the existence of a specific heat anomaly at Tc.

  520. Pentagonal-dodecahedral La<inf>2</inf> charge density in [80-I<inf>h</inf>]fullerene: La<inf>2</inf>@C<inf>80</inf>

    Eiji Nishibori, Masaki Takata, Makoto Sakata, Atsushi Taninaka, Hisanori Shinohara

    Angewandte Chemie - International Edition 40 (16) 2998-2999 2001年8月17日

    DOI: 10.1002/1521-3773(20010817)40:16<2998::AID-ANIE2998>3.0.CO;2-4  

    ISSN:1433-7851

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    A double shell of Platonic solids: A trajectory that connects the six-numbered rings of Ih-C80 is followed by the two La atoms of La2@C80 according to maximum entropy/Rietveld analysis of the synchtron powder-diffraction data. The result is a pentagonal-dodecahedral charge-density distribution for La2 (brown in the picture) inside the icodsahedral C80 cage (green).

  521. Multiwalled carbon nanotubes grown in hydrogen atmosphere: An x-ray diffraction study

    Yutaka Maniwa, Ryuji Fujiwara, Hiroshi Kira, Hideki Tou, Eiji Nishibori, Masaki Takata, Makoto Sakata, Akihiko Fujiwara, Xinluo Zhao, Sumio Iijima, Sumio Iijima, Yoshinori Ando

    Physical Review B - Condensed Matter and Materials Physics 64 (7) 731051-731054 2001年8月15日

    DOI: 10.1103/PhysRevB.64.073105  

    ISSN:0163-1829

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    X-ray diffraction study of multiwalled carbon nanotube (MWNT) grown by arc discharge in hydrogen atmosphere is presented. It is found that the thermal-expansion coefficient along the radial direction of MWNT is widely distributed in a range from 1.6× 10-5 K-1 to 2.6×10-5 K-1, indicating the existence of both of Russian doll MWNT and highly defective MWNT Russian doll MWNT is suggested to have the outer diameter less than ∼ 100 Å. Thicker MWNT's are typically highly defective, and may have the jelly roll (scroll) or defective polygonal structure consisting of flat graphite domains.

  522. Charge density study of C<inf>60</inf> superconductors by MEM/Rietveld analysis

    M. Takata, E. Nishibori, M. Shinmura, H. Tanaka, K. Tanigaki, M. Kosaka, M. Sakata

    Materials Science and Engineering A 312 (1-2) 66-71 2001年8月15日

    DOI: 10.1016/S0921-5093(00)01894-3  

    ISSN:0921-5093

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    The charge density study of alkali metal doped fullerenes, Rb2CsC60, K2RbC60, Na2RbC60 and Li2CsC60, was carried out at room temperature by MEM/Rietveld analysis, which is the combination of the Maximum Entropy Method (MEM) and Rietveld analysis using synchrotron radiation powder data. The distinctly different features of charge densities of the C60 molecules relating to the superconducting properties were revealed in the obtained MEM charge densities. For Na2RbC60, K2RbC60 and Rb2CsC60, the rotations of the C60 molecules were virtually quenched while the C60 molecule in Li2CsC60 was in an orientational disorder. In the interatomic region, the overlapped charge density indicating the existence of a covalent bond was not found significantly between the C60 molecules and doped metal atoms for the four materials. However, in the MEM charge densities, the relative differences among them were found significantly for the charge deficiencies of the doped metal atoms which should be associated with charge transfer from the metal atoms to the C60 molecule. © 2001 Elsevier Science B.V. All rights reserved.

  523. Bonding nature in MgB<inf>2</inf>

    Eiji Nishibori, Masaki Takata, Makoto Sakata, Hiroshi Tanaka, Takahiro Muranaka, Jim Akimitsu

    Journal of the Physical Society of Japan 70 (8) 2252-2254 2001年8月

    DOI: 10.1143/JPSJ.70.2252  

    ISSN:0031-9015

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    The accurate charge density of MgB2 was observed at room temperature (R.T.) and 15 K by the maximum entropy method (MEM)/Rietveld analysis using synchrotron radiation powder data. The obtained charge density clearly revealed the covalent bonding feature of boron forming the 2D honeycomb network in the basal plane, on the other hand, Mg is found to be in divalent state. A subtle but clear charge concentration was found on boron 2D sheets at 15 K, which should be related to superconductivity.

  524. Structural properties and thermodynamic stability of Ba-doped silicon type-I clathrates synthesized under high pressure

    Akiko Kitano, Koji Moriguchi, Mitsuharu Yonemura, Shinji Munetoh, Akira Shintani, Hiroshi Fukuoka, Shoji Yamanaka, Eiji Nishibori, Masaki Takata, Makoto Sakata

    Physical Review B - Condensed Matter and Materials Physics 64 (4) 452061-452069 2001年7月15日

    DOI: 10.1103/physrevb.64.045206  

    ISSN:0163-1829

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    We present a joint experimental and theoretical study of the stability and structural properties of Ba-doped silicon type-I clathrates Ba8Si46 synthesized under high pressures. The thermodynamic stability of Ba8Si46 under high pressure has been discussed from the total energy calculations of some barium silicides within the local density approximation (LDA). We have theoretically found that pressure favors the formation of the clathrate phase as experimentally observed. We have also performed a synchrotron x-ray-diffraction experiment of Ba8Si46 prepared under high pressures. Some of the missing endohedral Ba elements in the small cage of Si(20) have been observed by x-ray crystallography, while big cages of Si(24) are found to be completely occupied by Ba elements. The stabilization energies of Ba atoms in the endohedral sites estimated within the present LDA calculation suggest that this is presumably attributed to the energetical site preference of Ba atoms between d(6) and a(2) sites. In addition, the isothermal parameter of Ba in the big cage of Si(24) has been found to be larger than that in the small Si(20) unit, which is consistent with some theoretical predictions in earlier works.

  525. Effects of B-site disorder in Sr<inf>2</inf>FeMoO<inf>6</inf> with double perovskite structure

    Yutaka Moritomo, Naoyuki Shimamoto, Sheng Xu, Akihiko Machida, Eiji Nishibori, Masaki Takata, Makoto Sakata, Arao Nakamura

    Japanese Journal of Applied Physics, Part 2: Letters 40 (7 A) 2001年7月1日

    DOI: 10.1143/jjap.40.l672  

    ISSN:0021-4922

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    Heat treatment effects on the physical properties have been investigated for Sr2FeMoO6 single crystals with double perovskite structure. We have evaluated the occupancy g of the Fe3+ ion on one sublattice of the perovskite-B site by Rietveld refinement of the synchrotron-radiation X-ray powder patterns. Both the saturation magnetization Ms and critical temperature Tc for the ferrimagnetic transition decrease linearly with g in the large-g region (g ≥ ∼0.84), but begin to deviate from the empirical relations for g ≤ ∼ 0.84. We interpreted this behavior in terms of variation of the correlation length of the spin ordering.

  526. Vibrational Spectroscopy of Superconducting MgB<inf>2</inf> by Neutron Inelastic Scattering

    Takahiro Muranaka, Serena Margadonna, Isabelle Maurin, Kierin Brigatti, Daniele Colognesi, Kosmas Prassides, Yoshihiro Iwasa, Masatoshi Arai, Masaki Takata, Jun Akimitsu

    Journal of the Physical Society of Japan 70 (6) 1480-1482 2001年6月

    DOI: 10.1143/JPSJ.70.1480  

    ISSN:0031-9015

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    Neutron inelastic scattering measurements have been performed on superconducting MgB2 above and below Tc. The temperature dependence of the generalized phonon density-of-states showed clear anomalous behaviour near 24 meV in the acoustic phonon region, which may be interpreted as evidence of a substantial contribution to the total electron-phonon coupling strength deriving from these phonons. Weaker evidence for a corresponding response in the high-energy B bond stretching phonons was also encountered.

  527. Charge Ordering in the Geometrically Frustrated Spinel AlV<inf>2</inf>O<inf>4</inf>

    Ken Ichiro Matsuno, Takuro Katsufuji, Shigeo Mori, Yutaka Moritomo, Akihiko Machida, Eiji Nishibori, Masaki Takata, Makoto Sakata, Naoki Yamamoto, Hidenori Takagi

    Journal of the Physical Society of Japan 70 (6) 1456-1459 2001年6月

    DOI: 10.1143/JPSJ.70.1456  

    ISSN:0031-9015

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    We have found that spinel AlV2O4 shows a phase transition at ∼700K with anomalies of transport and magnetic properties. It is clarified that this corresponds to a charge-ordering transition, where the V2.5+ ions are separated into three V2.5-δ ions and one V2.5+3δ ion. This three-one type of charge ordering, which is coupled with rhombohedral distortion along the (111) axis, reduces the high degeneracy of ground states inherent in this spinel structure, and thus can be understood in terms of "charge frustration.".

  528. MEM/Rietveld 法による精密構造物性の研究

    高田 昌樹, 西堀 英治, 坂田 誠

    まてりあ : 日本金属学会会報 40 (3) 267-276 2001年3月20日

    出版者・発行元:The Japan Institute of Metals and Materials

    DOI: 10.2320/materia.40.267  

    ISSN:1340-2625

  529. A scandium carbide endohedral metallofullerene: (Sc<inf>2</inf>C<inf>2</inf>)@C<inf>84</inf>

    Chun Ru Wang, Tsutomu Kai, Testuo Tomiyama, Takuya Yoshida, Yuji Kobayashi, Eiji Nishibori, Masaki Takata, Makoto Sakata, Hisanori Shinohara

    Angewandte Chemie - International Edition 40 (2) 397-399 2001年1月19日

    DOI: 10.1002/1521-3773(20010119)40:2<397::AID-ANIE397>3.0.CO;2-3  

    ISSN:1433-7851

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    Not Sc2@C86 but Sc2C2@C84: that is the conclusion of 13C NMR spectroscopic and synchrotron X-ray powder diffraction studies on a new metallofullerene obtained by arc discharge of Sc2O3/graphite rods. The picture shows a schematic representation of the deduced structure, in which the novel scandium carbide cluster Sc2C2 is encaged in D2d-C84.

  530. Compressibility of the MgB<inf>2</inf> superconductor

    K. Prassides, Y. Iwasa, T. Ito, Dam H. Chi, K. Uehara, E. Nishibori, M. Takata, S. Sakata, Y. Ohishi, O. Shimomura, T. Muranaka, J. Akimitsu

    Physical Review B - Condensed Matter and Materials Physics 64 (1) 125091-125094 2001年

    ISSN:0163-1829

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    Considerable excitement has been caused recently by the discovery that the binary-boride system with stoichiometry MgB2 is superconducting at the remarkably high temperature of 39 K [J. Nagamatsu, N, Nakagawa, T. Muranaka, Y. Zenitani, and J. Akimitsu, Nature 410, 63 (2001)]. This potentially opens the way to even higher-Tc values in a new family of superconductors with unexpectedly simple composition and structure. The simplicity in the electronic and crystal structures could allow the understanding of the physics of high-Tc superconductivity without the presence of the multitude of complicated features, associated with the cuprates. Synchrotron x-ray diffraction was used to measure the isothermal compressibility of MgB2, revealing a stiff tightly packed incompressible solid with only moderate bonding anisotropy between intralayer and interlayer directions. These results, combined with the pressure evolution of the superconducting transition temperature, Tc, establish its relation to the B and Mg bonding distances over a broad range of values.

  531. Compressibility of the (formula presented) superconductor

    K. Uehara, M. Takata, J. Akimitsu, K. Prassides, Y. Iwasa, Dam H. Chi, T. Ito, M. Sakata, E. Nishibori, Y. Ohishi, O. Shimomura, T. Muranaka

    Physical Review B - Condensed Matter and Materials Physics 64 (1) 2001年

    DOI: 10.1103/PhysRevB.64.012509  

    ISSN:1098-0121

    eISSN:1550-235X

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    Considerable excitement has been caused recently by the discovery that the binary-boride system with stoichiometry (formula presented) is superconducting at the remarkably high temperature of 39 K [J. Nagamatsu, N. Nakagawa, T. Muranaka, Y. Zenitani, and J. Akimitsu, Nature 410, 63 (2001)]. This potentially opens the way to even higher-(formula presented) values in a new family of superconductors with unexpectedly simple composition and structure. The simplicity in the electronic and crystal structures could allow the understanding of the physics of high-(formula presented) superconductivity without the presence of the multitude of complicated features, associated with the cuprates. Synchrotron x-ray diffraction was used to measure the isothermal compressibility of (formula presented) revealing a stiff tightly packed incompressible solid with only moderate bonding anisotropy between intralayer and interlayer directions. These results, combined with the pressure evolution of the superconducting transition temperature, (formula presented) establish its relation to the B and Mg bonding distances over a broad range of values. © 2001 The American Physical Society.

  532. Thermal expansion of single-walled carbon nanotube (SWNT) bundles: X-ray diffraction studies

    Hideki Tou, Yohji Achiba, Masaki Takata, Hiroyoshi Suematsu, Hiromichi Kataura, Ryuji Fujiwara, Hiroshi Kira, Yutaka Maniwa, Shinzo Suzuki, Makoto Sakata, Eiji Nishibori, Akihiko Fujiwara

    Physical Review B - Condensed Matter and Materials Physics 64 (24) 2001年

    DOI: 10.1103/PhysRevB.64.241402  

    ISSN:1098-0121

    eISSN:1550-235X

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    Thermal expansion coefficient in single-walled carbon nanotube bundles was determined as (formula presented) for the tube diameter and (formula presented) for the triangular lattice constant by means of x-ray scattering between 300 K to 950 K. The value for the intertube gap was (formula presented) which is larger than (formula presented) for the c-axis thermal expansion in graphite. The results reveal the presence of a remarkably larger lattice anharmonicity in nanotube bundles than that of graphite. The small value for the tube diameter is consistent with the seamless tube structure formed by a strong covalent bond between carbon atoms comparable to that in graphite. © 2001 The American Physical Society.

  533. Chemical pressure control of exchange interaction in Mo pyrochlore

    Y. Moritomo, Sh Xu, A. Machida, T. Katsufuji, E. Nishibori, M. Takata, M. Sakata, S. W. Cheong

    Physical Review B - Condensed Matter and Materials Physics 63 (14) 1444251-1444255 2001年

    DOI: 10.1103/physrevb.63.144425  

    ISSN:0163-1829

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    Structural parameters are systematically investigated for Mo pyrochlore R2Mo2O7 (R = Dy, Gd, Sm, and Nd) by means of synchrotron radiation x-ray powder diffraction. This system shows a crossover from the spin-glass (SG) state to the ferromagnetic metallic (FM) state as the averaged ionic radius rR of the rare-earth ion increases. We have found the Mo-O-Mo bond angle increases with rR from 129.7° for Dy2Mo2O7 (SG) to 131.5° for Nd2Mo2O7 (FM). This behavior is opposite to the so-called Kanamori-Goodenough rule.

  534. Enhanced specific heat jump in electron-doped (formula presented) Spin ordering driven by charge separation

    Y. Moritomo, A. Machida, E. Nishibori, M. Takata, M. Sakata

    Physical Review B - Condensed Matter and Materials Physics 64 (21) 2001年

    DOI: 10.1103/PhysRevB.64.214409  

    ISSN:1098-0121

    eISSN:1550-235X

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    Temperature variation of the magnetic susceptibility χ, resistivity ρ, specific heat C, and lattice constants has been investigated in electron-doped (formula presented) The parent (formula presented) is an antiferromagnetic band insulator, and shows an insulator-metal crossover with electron doping, together with an enhanced ferromagnetic component. We have found an enhancement of the specific heat jump (formula presented) at the spin-ordering temperature (formula presented) and interpreted the enhancement in terms of the intrinsic charge separation. © 2001 The American Physical Society.

  535. Charge density studies utilizing powder diffraction and MEM. Exploring of high Tc superconductors, C<inf>60</inf> superconductors and manganites

    M. Takata, E. Nishibori, M. Sakata

    Zeitschrift fur Kristallographie 216 (2) 71-86 2001年

    DOI: 10.1524/zkri.216.2.71.20335  

    ISSN:0044-2968

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    The recent progress of the accurate charge density studies by the Maximum Entropy Method (MEM) utilizing X-ray powder diffraction is reviewed with some examples. Results for PrBCO (PrBa2Cu3O7-δ), YBCO (YBa2Cu3O7-δ), C60 superconductors (Rb2CsC60, K2RbC60, Na2RbC60) and the layered manganite, NdSr2Mn2O7, which is well known as colossal magnetoresistive (CMR)-related material, are given. For non-super conductor, PrBCO, it is found in the MEM charge density that there exist directional robes of the charge density from Pr atom toward the O atoms in the CuO2 conduction planes. On the other hand, for a very well known high Tc super conductor, YBCO, appreciable charge densities in the interatomic region around the Y atom is not recognized in the MEM charge density. The distinct difference of the charge densities between PrBCO and YBCO presents clear experimental evidence of the hybridization between Pr(4f)-O(2pπ) orbitals which supports the idea that the hole trapping by the hybridized states suppresses the superconductivity in PrBCO. The MEM charge densities of the fullerene superconductors, Rb2CsC60, K2RbC60 and Na2RbC60, show distinct structural differences from that of non-superconductors, C60 and Li2CsC60, reflecting the superconducting properties. And the charge deficiencies of the doped metal atoms, which should be associated with charge transfer from the metal atoms to the C60 molecule seems to have strong correlation to the superconducting transition temperature, Tc. As the bigger the charge transfer, the higher the Tc. The accurate MEM charge density of antiferromagnetic manganite, NdSr2Mn2O7, presents the direct imaging of spontaneous ordering of the dx2- y2 orbital indicating anisotropic exchange couplings between the local-spins on the Mn sites, which causes an unique layered-type spin order. The theoretical background of the MEM is also mentioned in some detail.

  536. The large Debye-Scherrer camera installed at SPring-8 BL02B2 for charge density studies

    E. Nishibori, M. Takata, K. Kato, M. Sakata, Y. Kubota, S. Aoyagi, Y. Kuroiwa, M. Yamakata, N. Ikeda

    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 467-468 (PART II) 1045-1048 2001年

    DOI: 10.1016/S0168-9002(01)00639-8  

    ISSN:0168-9002

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    The design and performance of a large Debye-Scherrer Camera with imaging plate (IP) as a detector, which was very recently installed at SPring-8, BL02B2, is reported. By taking advantage of high beam quality of SPring-8, the camera enables one a rapid collection of a high counting statistics and high angular resolution powder pattern, which can lead to accurate structure analyses. The camera also provides easy access to structural changes at varied temperatures between 15-1000 K. The camera provides a rapid and accurate powder diffraction system utilizing third generation SR. © 2001 Elsevier Science B.V. All rights reserved.

  537. Interrelation between hume-rothery mechanism, hybridization and covalent bonds in aluminum- and boron-based icosahedral approximants and quasicrystals

    Kaoru Kimura, Kazuhiro Kirihara, Masaaki Fujimori, Takahiro Nakayama, Masaki Takata, Makoto Sakata

    Materials Research Society Symposium - Proceedings 643 2001年

    ISSN:0272-9172

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    Metallic-covalent bonding conversion in icosahedral clusters of Al and B by small changes of the structure was demonstrated by molecular orbital calculations. According to the electron density distribution obtained using the maximum entropy method and the Rietveld method, the bonding conversion phenomenon occurs even in cluster solids such as some Al- and B-based icosahedral approximant phases (Al12Re, α-AlMnSi, α-rhombohedral boron). The multiple-shell atomic structure, the electrical and optical conductivity are compared for metal doped β-rhombohedral boron and AlLiCu or AlPdRe icosahedral quasicrystal. Photoemission and electron energy loss spectroscopy investigations for V doped β-rhombohedral have been discussed. Conclusions are the following two. It is difficult to distinguish a Hume-Rothery, i.e. structure-induced, pseudogap, and a covalent bonding, i.e. hybridization, pseudogap for materials with a highly symmetric Brillouin zone and a strong potential for valence electrons. Because hybridization is necessary not only for covalent bonds but also for metallic ones, it is better to use the covalent bonding pseudogap than the hybridization pseudogap.

  538. Determination of spatially hybridized charge distribution and its effect on electron transport in the Al-Cu-Ru-Si 1/1-approximant - Theoretical basis for the Hume-Rothery rule

    U. Mizutani, T. Takeuchi, E. Banno, V. Fourneé, M. Takata, H. Sato

    Materials Research Society Symposium - Proceedings 643 2001年

    ISSN:0272-9172

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    The origin of the pseudogap across the Fermi level was investigated by analyzing the electronic structure calculated in the framework of the LMTO-ASA method for the RT-type Al-Mg-Zn and MI-type Al-Cu-Ru-Si 1/1-approximants. The pseudogap in the former is proved to originate from the interaction of electronic states with the Brillouin zone planes associated with reciprocal lattice vectors matching with the Fermi sphere in the extended zone scheme, in the latter, the Fermi surface-Brillouin zone interaction coupled with the hybridization effect between the Al-3p and transition metal d-states produces a deep pseudogap at the Fermi level. The real-space charge distribution for electrons at the Fermi level is calculated for the Al-Cu-Ru-Si 1/1-approximant. The charge distribution thus obtained could explain not only the possession of a large resistivity of this approximant but also evidenced that the icosahedral clusters play a key role in reducing the electronic energy in favor of quasicrystalline and approximant phases.

  539. Electron-density distribution of approximants of the icosahedral Al-based alloys by the maximum-entropy method and the Rietveld refinement

    K. Kirihara, T. Nakata, M. Takata, Y. Kubota, E. Nishibori, K. Kimura, M. Sakata

    Materials Science and Engineering A 294-296 492-495 2000年12月15日

    DOI: 10.1016/S0921-5093(00)01069-8  

    ISSN:0921-5093

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    The electron-density distributions of two approximants, metallic Al12Re constructed of 13 atoms icosahedra with the center Re atoms and non-metallic α-Al-Mn-Si constructed of 12 atoms icosahedra without the center atom, are obtained using the maximum entropy method with synchrotron radiation powder data. Since the minimum electron-density of Al12Re is about one hundred times larger than that of α-Al-Mn-Si, Al12Re has free electron background and apparently metallic bonding. α-Al-Mn-Si is found to have strong covalent bonds in the Mackay icosahedron and those between the glue atom sites and the Mackay icosahedron. The covalency of Al (or Si) icosahedron and that between Al (or Si) and Mn atoms are considered to be the origin of the pseudogap in the α-Al-Mn-Si rather than the Hume-Rothery mechanism.

  540. Atomic structure of the Al-Cu-Fe-Si 1/1-cubic approximant

    Tsunehiro Takeuchi, Hiroshi Yamada, Masaki Takata, Tamotsu Nakata, Nobuo Tanaka, Uichiro Mizutani

    Materials Science and Engineering A 294-296 340-344 2000年12月15日

    DOI: 10.1016/S0921-5093(00)01198-9  

    ISSN:0921-5093

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    By combining the X-ray Rietveld analysis with the high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), we have made a detailed structural analysis for the Mackay-type Al53Si9Cu25.5Fe12.5 1/1-cubic approximant. Electron diffraction measurements identified it as a simple cubic with a space group of Pm3, being the same as that of the Al-Mn-Si 1/1-cubic approximant (α-phase). Both atomic position and occupancy in every atomic site are refined by means of the Rietveld analysis with a choice of the Al-Mn-Si α-phase as the starting structure. The factors Rwp and RI, which are taken as measures for the precision of the Rietveld analysis, are reduced to 2.32 and 3.87%, respectively. Two different icosahedral clusters consisting of triply stacked atomic shells are formed at the vertex and body-centered positions in the CsCl-type unit cell. The number of transition metals involved in one of the clusters is much higher than in the other. In addition, we found that the R-factors are substantially reduced by introducing a `structural disorder' in the first shell of the cluster in one of the sublattices containing more transition metals. Since the occupancy in the first shell is reduced significantly, the structural disorder is most likely introduced by vacancies in that shell. The HAADF images taken along the [100], [110] and [111] directions agree well with the projection images calculated from the Rietveld-refined structure, lending a strong support to the validity of the present atomic structure model.

  541. Electron doping effects in conducting Sr<inf>2</inf>FeMoO<inf>6</inf>

    Y. Moritomo, Sh Xu, T. Akimoto, A. Machida, N. Hamada, K. Ohoyama, E. Nishibori, M. Takata, M. Sakata

    Physical Review B - Condensed Matter and Materials Physics 62 (21) 14224-14228 2000年12月1日

    DOI: 10.1103/PhysRevB.62.14224  

    ISSN:0163-1829

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    Effects of the electron doping on the magnetic and electronic properties have been investigated in the conducting double perovskite Sr2FeMoO6. Judging from the enhanced moment μMo at the Mo site, the doped electrons are considered to occupy mainly the down-spin Mo4d band. Filling dependence of the saturation magnetization Ms, the spin-wave stiffness coefficient Ds and thy γ coefficient are discussed on the basis of a LDA + U band calculation. We further discuss possible origins for the magnetism.

  542. Materials science: C<inf>66</inf> fullerene encaging a scandium dimer

    Chun Ru Wang, Tsutomu Kai, Tetsuo Tomiyama, Takuya Yoshida, Yuji Kobayashi, Eiji Nishibori, Masaki Takata, Makoto Sakata, Hisanori Shinohara

    Nature 408 (6811) 426-427 2000年11月23日

    DOI: 10.1038/35044195  

    ISSN:0028-0836

  543. Giant motion of La atom inside C<inf>82</inf> cage

    Eiji Nishibori, Masaki Takata, Makoto Sakata, Hiroshi Tanaka, Masaki Hasegawa, Hisanori Shinohara

    Chemical Physics Letters 330 (5-6) 497-502 2000年11月17日

    DOI: 10.1016/S0009-2614(00)01079-4  

    ISSN:0009-2614

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    An anomalous charge density distribution of La atom encapsulated in a C82 cage has been revealed for La@C82 by the maximum entropy method (MEM)/Rietveld analysis using synchrotron powder diffraction data. The obtained La atom charge density shows a feature almost like a bowl or a hemisphere, suggesting that the La atom has a giant motion (large amplitude motion) inside the C82 cage at room temperature. From the obtained MEM charge density, the main results are (1) the cage structure of La@C82 (I) has C2V symmetry; (2) La atom locates at an off-centered position adjacent to a six-membered ring of the carbon cage; (3) the nearest La-C distance is 2.55(8) Å and (4) the amount of charge transfer from the La atom to the carbon cage is about 3.2 e, which corresponds to the nominal electronic structure, La3+@C823-. © 2000 Elsevier Science B.V.

  544. Microdomain structure of Cr-doped manganites: Nd<inf>1/2</inf>Ca<inf>1/2</inf>(Mn,Cr)O<inf>3</inf>

    Akihiko Machida, Yutaka Moritomo, Eiji Nishibori, Masaki Takata, Makoto Sakata, Kenji Ohoyama, Shigeo Mori, Naoki Yamamoto, Arao Nakamura

    Journal of the Physical Society of Japan 69 (11) 3536-3539 2000年11月

    DOI: 10.1143/JPSJ.69.3536  

    ISSN:0031-9015

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    Crystal and magnetic structures of Cr-doped manganites. Nd1/2Ca1/2Mnl-yCryO3 (y = 0.00 and 0.03), have been investigated by synchrotron radiation (SR) x-ray powder diffraction as well as neutron powder diffraction measurements. A detailed analysis of the high-resolution x-ray profile has revealed that the Cr-doped compound exhibits broad extra reflections, suggesting the formation of microdomains below the charge-ordering temperature TCO. The origin of the microdomain structure is discussed in terms of the charge separation.

  545. Covalent bonds in AlMnSi Icosahedral quasicrystalline approximant

    K. Kirihara, T. Nakata, M. Takata, Y. Kubota, E. Nishibori, K. Kimura, M. Sakata

    Physical Review Letters 85 (16) 3468-3471 2000年10月16日

    DOI: 10.1103/PhysRevLett.85.3468  

    ISSN:0031-9007

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    This study used the maximum entropy method with synchrotron radiation powder data to examine the bonding nature of icosahedral clusters of 12 atoms in nonmetallic α-AlMnSi 1/1-cubic approximant phase and 13 atoms in metallic Al12Re phase, respectively. Regarding α-AlMnSi, the origin of the pseudogap is considered to be due to the covalent bonds rather than the Hume-Rothery mechanism. In the icosahedral Al12 cluster with central Re atom, the enhancement of electrical resistivity with increasing concentration of transition metals is due to the enhanced covalency between Al and transition metal.

  546. Crystal and magnetic structure of conducting double perovskite Sr<inf>2</inf>FeMoO<inf>6</inf>

    Yutaka Moritomo, Sheng Xu, Akihiko Machida, Takumi Akimoto, Eiji Nishibori, Masaki Takata, Makoto Sakata, Kenji Ohoyama

    Journal of the Physical Society of Japan 69 (6) 1723-1726 2000年6月

    DOI: 10.1143/JPSJ.69.1723  

    ISSN:0031-9015

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    We have investigated, crystal and magnetic structure of conducting double perovskite transition metal oxide, Sr2FeMoO6, which has been grown by the floating-zone method. The resisitvity shows T2-dependence in a wide temperature range (50-350 K), perhaps due to magnon scattering. We further have determined the crystal and magnetic structure in the ferrimagnetic state by means of synchrotron radiation X-ray powder measurements as well as neutron powder diffraction experiments.

  547. A charge density study of the intermetallic compound MgCu<inf>2</inf> by the maximum entropy method

    Y. Kubota, M. Takata, M. Sakata, T. Ohba, K. Kifune, T. Tadaki

    Journal of Physics Condensed Matter 12 (7) 1253-1259 2000年2月21日

    DOI: 10.1088/0953-8984/12/7/309  

    ISSN:0953-8984

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    The charge density distribution of the intermetallic compound MgCu2 is obtained by the maximum entropy method (MEM) from the synchrotron powder diffraction data. In the MEM charge density map, the overlap of electron densities was clearly observed between the neighbouring Cu atoms. This clearly shows that there is a rather strong covalent bond between Cu-Cu atoms. It is also found that the Cu-Cu bonding is along the very well known kagome net, which characterizes the Laves phase structure. At least, in the case of MgCu2, the kagomé network is the electronic network in reality rather than a geometrical concept to represent structural characteristics of Laves phase compounds. © 2000 IOP Publishing Ltd.

  548. Structural studies of cation disorder in the ferroelectric oxide SrBi2Ta2O9

    R Macquart, BJ Kennedy, Y Kubota, E Nisibori, M Takata

    FERROELECTRICS 248 (1-4) 27-32 2000年

    出版者・発行元:GORDON BREACH PUBLISHING, TAYLOR & FRANCIS GROUP

    ISSN:0015-0193

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    The crystal structure of a bulk sample of the ferroelectric oxide SrBi2Ta2O9 refined using a combination of synchrotron and neutron powder diffraction data is reported. At room temperature SrBi2Ta2O9 has an orthorhombic structure with space group A2(1)am. The bulk sample of SrBi2Ta2O9 studied was quenched from 600 degreesC and was found to exhibit small, but significant amounts of disorder between the Sr and Bi cations.

  549. Imaging of the electron density distributions of hydrogen in LiH and LiOH by maximum entropy method

    Shigefumi Yamamura, Satoshi Kasahara, Masaki Takata, Yoko Sugawara, Matoto Sakata

    Journal of Physics and Chemistry of Solids 60 (10) 1721-1724 1999年10月

    DOI: 10.1016/S0022-3697(99)00026-8  

    ISSN:0022-3697

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    In order to explore the electron distribution of hydrogen, an electron density study was carried out by maximum entropy method (MEM) using the single crystal X-ray diffraction data of LiH measured by Vidal-Valat et al. [Acta Crystallogr. A48 (1992) 46-60] and those of LiOH measured by Gottlicher and Kieselbach [Acta Crystallogr. A32 (1976) 185-192]. It was found that the electron distribution of hydrogen in LiH is very spherical as a consequence of high symmetrical crystalline field. It was also recognized that there exists very weak covalent bond between lithium and hydrogen along the 〈100〉 direction. These features were consistent with the results of difference Fourier synthesis and multipole analysis by Vidal-Valat et al. Contrary to the LiH case, the position of hydrogen in LiOH was hardly assigned from the electron density map and only the contribution of hydrogen was recognized as a distortion of electron clouds of OH ellipse. The present study demonstrated that the electron distribution of hydrogen can be detected by MEM but it should be kept in mind that the distribution of electron from hydrogen was severely affected by the crystal field, which may result in the fact that the electron from hydrogen is far from a spherical distribution.

  550. Direct Observation of Orbital Order in Manganites by MEM Charge-Density Study

    Masaki Takata, Eiji Nishibori, Kenichi Kato, Makoto Sakata, Yutaka Moritomo

    Journal of the Physical Society of Japan 68 (7) 2190-2193 1999年7月

    DOI: 10.1143/JPSJ.68.2190  

    ISSN:0031-9015

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    We have investigated the charge-density distribution of an antiferromagnetic bi-layered manganite, NdSr2Mn2O7, by the maximum entropy method (MEM) using the synchrotron X-ray powder data. The magnetic structure below TN = 150 K is known to be a layered-type (A-type). We have found a significant change of the electron distribution around the Mn site below TN. Our observation indicates dx2 - y2-orbilal polarization in the A-type antiferromagnetic state.

  551. X線回折法による金属内包フラーレンの構造研究

    高田 昌樹

    日本結晶学会誌 41 (2) 112-121 1999年4月28日

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.40.Supplement_3  

    ISSN:0369-4585

  552. High-pressure neutron and X-ray studies on the Mott transition of BaCoS<inf>2</inf>

    M. Kanada, H. Harashina, H. Sasaki, K. Kodama, M. Sato, K. Kakurai, M. Nishi, E. Nishibori, M. Sakata, M. Takata, T. Adachi

    Journal of Physics and Chemistry of Solids 60 (8) 1181-1183 1999年

    DOI: 10.1016/S0022-3697(99)00078-5  

    ISSN:0022-3697

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    X-ray Rietveld analyses for BaCoS2 under high pressure and magnetic excitation measurements for BaCo1-xNixS2 at ambient pressure and for BaCoS2 under high pressure have been carried out. Atomic distances in a CoS5 pyramid abruptly change in the narrow region around the Mott metal-insulator transition with increasing external pressure (p). It suggests that the redistribution of electron numbers among the relevant bands occurs together with the p-induced Mott transition. The characteristic energy of the spin fluctuation behaves rather differently in two kinds of metallic phases induced by varying x and p, indicating that the main driving forces of the Mott transitions are different.

  553. Peculiar Covalent Bonds in ∝-Rhombohedral Boron

    M. Fujimori, T. Nakata, T. Nakayama, E. Nishibori, K. Kimura, M. Takata, M. Sakata

    Physical Review Letters 82 (22) 4452-4455 1999年

    DOI: 10.1103/PhysRevLett.82.4452  

    ISSN:0031-9007

    eISSN:1079-7114

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    A peculiar bonding feature of ∝-rhombohedral boron is found in the electron density distribution of the icosahedral B12 cluster. The electron density distribution is obtained by using the maximum entropy method with synchrotron radiation powder data. It clearly shows the characteristic two- and three-center covalent bond network which threads through atoms on the cluster surface. Besides, two kinds of covalent bonds in intercluster space are also shown in detail: a three-center trilaterally formed bond among the three clusters and a two-center bond with a remarkable feature of a bent bond between the clusters. The obtained covalent bonding features indicate the cluster-based nature of this material. © 1999 The American Physical Society.

  554. Nuclear density distribution in KH<inf>2</inf>PO<inf>4</inf> determined by the combined software system REMEDY

    S. Kumazawa, S. Yamamura, E. Nishibori, M. Takata, M. Sakata, F. Izumi, Y. Ishii

    Journal of Physics and Chemistry of Solids 60 (8) 1407-1409 1999年

    DOI: 10.1016/S0022-3697(99)00128-6  

    ISSN:0022-3697

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    The nuclear density distributions for both paraelectric and ferroelectric phases of KH2PO4 (KDP) were obtained by the software system named REMEDY, which is a combined program system of Rietveld refinement, RIETAN-98, and the maximum entropy method, MEND for neutron diffraction. The experimental data were collected by HRPD at JRR-3M. The specimen used was non-deuterated KDP, which caused no real problem in finding out the accurate proton distribution despite the higher background level. The results show high contrast as for proton distributions; symmetric double maxima between two oxygen atoms for a disordered paraelectric phase and a harmonic single maximum for an ordered ferroelectric phase.

  555. Triangle scandium cluster imprisoned in a fullerene cage

    Masaki Takata, Eiji Nishibori, Makoto Sakata, Masayasu Inakuma, Etsuji Yamamoto, Hisanori Shinohara

    Physical Review Letters 83 (11) 2214-2217 1999年1月1日

    DOI: 10.1103/PhysRevLett.83.2214  

    ISSN:0031-9007

    eISSN:1079-7114

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    The endohedral structure of tri-metallofullerene Sc3@C82 is determined by the maximum entropy method (MEM) combined with the Rietveld method using synchrotron radiation powder data. The result reveals for the first time that Sc atoms are encapsulated in the form of a triangle Sc cluster inside the C3V−C82 fullerene. The charge state of the encaged trimer is also determined as Sc3+3@C3−82 from the MEM charge density. The Sc-Sc distance in the equilateral triangular Sc3 cluster is 2.3(3)Å © 1999 The American Physical Society.

  556. Determination of the cage structure of Sc@C<inf>82</inf> by synchrotron powder diffraction

    Eiji Nishibori, Masaki Takata, Makoto Sakata, Masayasu Inakuma, Hisanori Shinohara

    Chemical Physics Letters 298 (1-3) 79-84 1998年12月11日

    DOI: 10.1016/S0009-2614(98)01133-6  

    ISSN:0009-2614

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    The cage structure of Sc@C82 (isomer I) has been determined by a synchrotron radiation powder structural analysis using the maximum entropy method (MEM). From the MEM charge density obtained the cage structure of the endohedral Sc@C82 (I) is experimentally determined to have C2V symmetry. Inside the carbon cage, the Sc atom is located at an off-center position adjacent to a carbon six-membered ring. The nearest Sc-C distance determined from the MEM charge density is 2.53(8) Å. The charge transfer from Sc to C has been estimated to be 2.2e, which is consistent with the ultraviolet photoelectron spectra and theoretical results.

  557. Electron Density Distribution of Wurtzite-Type Gallium Nitride by Maximum Entropy Method

    Tomohiro Ikeda, Masaki Takata, Makoto Sakata, Janusz Waliszewski, Ludwik Dobrzynski, S. Porowski, J. Jun

    Journal of the Physical Society of Japan 67 (12) 4104-4109 1998年12月

    DOI: 10.1143/JPSJ.67.4104  

    ISSN:0031-9015

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    The electron density distribution of wurtzite-type gallium nitride (w-GaN) was obtained by the Maximum Entropy Method (MEM) using the Synchrotron Radiation powder data. Contribution of the very minor zinc blende-type phase (z-GaN) to the observed powder data was eliminated by the modified Rietveld method. In the obtained MEM electron density distribution map, there are two kinds of Ga-N covalent bonds. The electron density at the saddle point of Ga-N bond parallel to [001] axis is 0.5 [e/Å3]. On the other hand, that of the other three equivalent Ga-N bonds are 0.8 [e/Å3]. Furthermore, it is found that the electron distribution of N atom shows asymmetric distortion. These features suggest asymmetric thermal vibrations of N atom which are restricted by Ga-N bonds.

  558. Nature of the Hydrogen Bond in Tetragonal KDP (KH<inf>2</inf>PO<inf>4</inf>) Observed by Maximum Entropy Method

    Shigefumi Yamamura, Masaki Takata, Makoto Sakata, Yoko Sugawara

    Journal of the Physical Society of Japan 67 (12) 4124-4127 1998年12月

    DOI: 10.1143/JPSJ.67.4124  

    ISSN:0031-9015

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    In order to explore the nature of the hydrogen bond, the electron density distribution of KH2PO4 (KDP) at room temperature was obtained by the maximum entropy method (MEM) using synchrotron radiation X-ray powder diffraction data. In the obtained electron density distribution maps, the contour lines linked the two oxygen atoms of neighboring PO4 groups and a hydrogen-bonding network was clearly seen. However, no local maxima of electron density due to hydrogen atoms were recognized. This figure of hydrogen bonding in KDP is similar to that in ice (Ih), which is the only hydrogen-bonded compound previously analyzed by MEM. In both cases, the hydrogen atoms are believed to be disordered between the two oxygen atoms. The present study shows that the character of the hydrogen bond in crystalline materials can be described clearly by MEM, even in the case where heavier atoms such as K and P exist besides O atoms.

  559. Charge density distributions of strontium titanate obtained by the maximum entropy method

    T. Ikeda, T. Kobayashi, M. Takata, T. Takayama, M. Sakata

    Solid State Ionics 108 (1-4) 151-157 1998年5月1日

    DOI: 10.1016/s0167-2738(98)00033-2  

    ISSN:0167-2738

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    Strontium titanate (SrTiO3) shows a displacive phase transition at 110 K. In order to study electron level structural changes throughout the phase transition, the charge density distributions of SrTiO3 were obtained by applying the Maximum Entropy Method (MEM) to X-ray diffraction data at Room Temperature (R.T.) and 70 K. From the MEM charge densities at R.T., it was found that Ti-O shows a rather strong covalent bond and that no covalency of Sr atoms was detected, which means that the Sr atom exists as an ion. From these results, chemical bonds of SrTiO3 could be described as the Sr ion floating electro-statically between three dimensional Ti-O networks. The symmetry of the lattice changes through the 110 K phase transition, which causes the super-lattice reflection at the R point. The displacement of oxygen atoms throughout the phase transition can be easily seen by taking the difference in charge density distribution between these two temperatures. The MEM charge densities at 70 K reveal that the structural changes throughout the phase transition are rather small, that is, the Ti-O strong covalent bond is maintained. The nature of the chemical bond of Sr atoms is basically unchanged. © 1998 Elsevier Science B.V. All rights reserved.

  560. Structural studies of endohedral metallofullerenes by synchrotron radiation powder diffraction

    E. Nishibori, M. Takata, M. Sakata, H. Shinohara

    Journal of Synchrotron Radiation 5 (3) 977-979 1998年5月1日

    DOI: 10.1107/S0909049597016816  

    ISSN:0909-0495

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    The endohedral natures of the metallofullerenes Y@C82 and Sc2@C84 are described based on synchrotron radiation powder diffraction experiments. For structural analysis, a combination of the maximum-entropy method (MEM) and Rietveld refinement was employed to analyse the complicated powder pattern. The obtained MEM charge densities show a clear distinction of the endohedral natures of the mono- and dimetallofullerenes.

  561. マキシマム・エントロピー法によるCu-Al-Ni合金の電子密度分布

    籠谷 友美, 久保田 佳基, 木舩 弘一, 唯木 次男, 高田 昌樹, 坂田 誠, 中田 芳幸

    日本結晶学会誌 40 204-204 1998年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.40.Supplement_204  

    ISSN:0369-4585

  562. Laves相化合物MgCu<SUB>2</SUB>およびMgZn<SUB>2</SUB>の電子密度分布

    久保田 佳基, 高田 昌樹, 坂田 誠, 大庭 卓也, 木舩 弘一, 唯木 次男

    日本結晶学会誌 40 201-201 1998年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.40.Supplement_201  

    ISSN:0369-4585

  563. La@C<SUB>82</SUB>におけるケージ内La原子の描像

    西堀 英治, 高田 昌樹, 坂田 誠, 長谷川 正樹, 篠原 久典

    日本結晶学会誌 40 156-156 1998年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.40.Supplement_156  

    ISSN:0369-4585

  564. 低温におけるNdSr<SUB>2</SUB>Mn<SUB>2</SUB>O<SUB>7</SUB>の電子レベルにおける構造変化

    加藤 健一, 西堀 英治, 高田 昌樹, 坂田 誠, 守友 浩

    日本結晶学会誌 40 203-203 1998年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.40.Supplement_203  

    ISSN:0369-4585

  565. Refinement in crystal structure of MoSi<inf>2</inf>

    Y. Harada, M. Morinaga, D. Saso, M. Takata, M. Sakata

    Intermetallics 6 (6) 523-527 1998年

    DOI: 10.1016/S0966-9795(97)00102-7  

    ISSN:0966-9795

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    The crystal structure of MoSi2 was investigated using a synchrotron X-ray powder diffraction method. From the Rietveld analysis it was shown that MoSi2 had a tetragonal structure of the space group I4/mmm and the lattice parameters were a = 0·32064(2) nm and c = 0·78478(8) nm. The position of Si atoms in the 4e site was determined to be (0, 0, 0·3353). There was a small shift in the z position, as compared to the previously reported value, 0·3333. The electronic structure of MoSi2 was calculated by the DV-Xα molecular orbital method employing the refined structural parameters, and this showed that there was a strong covalent bond between Si atoms aligned along the c axis in MoSi2. © 1998 Published by Elsevier Science Limited. All rights reserved.

  566. Size-dependent enhancement of nonlinear optical susceptibilities due to confined excitons in CuBr nanocrystals

    Yingli Li, Masaki Takata, Arao Nakamura

    Physical Review B - Condensed Matter and Materials Physics 57 (15) 9193-9200 1998年

    DOI: 10.1103/PhysRevB.57.9193  

    ISSN:1098-0121

    eISSN:1550-235X

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    We have investigated the third-order nonlinearity on resonance with the confined exciton level in CuBr nanocrystals with radii in the range (Formula presented) nm embedded in glass by means of degenerate four-wave mixing, time-resolved luminescence, and resonant luminescence measurements. The third-order optical susceptibility (Formula presented) exhibits resonant behaviors at (Formula presented) and (Formula presented) excitons, which are weakly confined in nanocrystals. The figure of merit (Formula presented) increases with increasing radius (Formula presented) in the whole range studied here. We have measured homogeneous widths and lifetimes of (Formula presented) excitons and obtained size dependences of those relaxation parameters. Assuming a two-level atomic model for the confined exciton, we have deduced the size dependence of the oscillator strength of (Formula presented) excitons from the measured lifetimes, homogeneous widths, and (Formula presented). The oscillator strength exhibits the (Formula presented) dependence in the whole range studied here, which reveals the giant oscillator strength effect on the confined exciton that is coherently generated in the nanocrystal. The oscillator strength per nanocrystal is enhanced by a factor (Formula presented) for (Formula presented) nm compared to that of bulk excitons. We also discuss the derivation of (Formula presented) in the stationary regime from the (Formula presented) in the transient regime where the nonlinear time response shows a multiexponential decay. © 1998 The American Physical Society.

  567. Composition dependence of the atomic structure of Al<inf>x</inf>Mg<inf>39·5</inf>Zn<inf>60· 5-x</inf>(20·5 ≤ x ≤ 50·5) 1/1 - 1/1 - 1/1 approximants determined by the rietveld method

    U. Mizutani, W. Iwakami, T. Takeuchi, M. Sakata, M. Takata

    Philosophical Magazine Letters 76 (5) 349-356 1997年11月

    DOI: 10.1080/095008397178959  

    ISSN:0950-0839

    eISSN:1362-3036

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    The atomic structure of the AlxMg39.0Zn60.5-x(20-5≤x≤ 50-5) 1/1 - 1/1 -1/1 approximants has been determined as a function of the Al concentration x by applying the Rietveld method to the X-ray powder diffraction data. The refinement was accomplished by using the data due to Bergman et al. as starting parameters- It is shown that the centre of the cluster is only 10% occupied by the Al atom at x = 20·5 but becomes essentially vacant when x exceeds 30. The sites corresponding to the vertex of the icosahedral cluster in the first shell are 80% occupied by the Zn atoms and the remaining sites by the Al atoms in the concentration range x ≤40. We also point out, from the Al concentration dependence of the interatomic distance of various atomic pairs, that the free-electron-like bonding mechanism dominates the Al-Mg-Zn approximants. This is consistent with previous studies of the electronic structure for the present approximants. © 1997 Taylor & Francis Ltd.

  568. Structural Studies on the Phase Transition of La<inf>3</inf>Ni<inf>2</inf>O<inf>6.92</inf> at about 550 K

    Hisashi Sasaki, Hiroshi Harashina, Satoshi Taniguchi, Mayumi Kasai, Yoshiaki Kobayashi, Masatoshi Sato, Takashi Kobayashi, Tomohiro Ikeda, Masaki Takata, Makoto Sakata

    Journal of the Physical Society of Japan 66 (6) 1693-1697 1997年6月

    DOI: 10.1143/JPSJ.66.1693  

    ISSN:0031-9015

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    Structural studies of La3Ni2O6.92 with a double layered perovskite structure have been performed by the X-ray Rietveld analyses between 300K and 650K. The interatomic distance between Ni and the apical oxygen (on the outside of NiO2 double layer) rapidly increases around the phase-transition temperature TB ∼ 550K with decreasing temperature. Then, the energy of the (3z2-r2) band is considered to shift downwards with respect to that of the (x2-y2) band with decreasing temperature and the lower Hubbard band of the former becomes to be (almost) fully occupied at the transition temperature, which induces the Mott transition (delocalized-localized transition) of the (3z2-r2) electrons.

  569. Quantum confinement of carriers and excitons due to the interface charges of copper halide nanocrystals in glass

    Arao Nakamura, Manabu Ohta, Satoshi Sasaki, Masaki Takata

    Journal of Luminescence 72-74 370-372 1997年6月

    DOI: 10.1016/S0022-2313(96)00333-X  

    ISSN:0022-2313

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    Quantum confinement effects have been investigated using nanocrystals of CuBrxCl1-x solid solutions with different composition ratios. The size dependence of the exciton energy exhibits a larger dependence than that expected by the simple confinement model. The results can be explained well taking into account the Coulomb repulsive potential due to the charge localized at the interface. The simple quantum mechanical calculations confirm that the localized charge raises the confinement energy level.

  570. Structure of endohedral dimetallofullerene Sc<inf>2</inf>@C<inf>84</inf>

    Masaki Takata, Eiji Nishibori, Buntaro Umeda, Makoto Sakata, Etsuji Yamamoto, Hisanori Shinohara

    Physical Review Letters 78 (17) 3330-3333 1997年4月

    DOI: 10.1103/PhysRevLett.78.3330  

    ISSN:0031-9007

    eISSN:1079-7114

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    The endohedral nature of dimetallofullerene Sc2@C84 is determined for the first time by a method which is a combination of the maximum entropy method (MEM) and the Rietveld refinement from synchrotron powder diffraction data. The obtained MEM charge density clearly shows the D2d-symmetry cage structure, indicating the rotation of Sc2@C84 molecules in solid state is almost quenched even at room temperature. From the MEM charge density, the encapsulated Sc-Sc distance and the nearest Sc-C distance are 3.9(1) and 2.4(1) Å, respectively. © 1997 The American Physical Society.

  571. 3. 微少量・高精度・極限にせまる 金属内包フラーレンを粉末X線で見る

    高田 昌樹, 坂田 誠

    日本結晶学会誌 39 (1) 72-77 1997年2月28日

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.39.72  

    ISSN:0369-4585

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    The necessity of the synchrotron X-ray powder diffractometry is mentioned to study the endohedral metallofullerenes. The results of Y@C<SUB>82</SUB> is also given.

  572. Charge density of hexagonal boron nitride using synchrotron radiation powder data by Maximum Entropy Method

    S. Yamamura, M. Takata, M. Sakata

    Journal of Physics and Chemistry of Solids 58 (2) 177-183 1997年2月

    DOI: 10.1016/S0022-3697(96)00134-5  

    ISSN:0022-3697

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    In order to explore the bonding nature of hexagonal boron nitride (h-BN), a charge density study of h-BN has been carried out by the Maximum Entropy Method (MEM) using the Synchrotron Radiation powder data. In the obtained MEM charge density distribution map, the strong directional B-N bond is found in the basal plane which corresponds to a a bond by sp2 hybridization. On the other hand, appreciable charge densities are not observed in the interlayer region, indicating chemical bonding nature between the basal planes is ionic. These fundamental features show good accordance with the charge density derived from the accurate self-consistent full-potential linearized augmented-plane-wave calculation. Thus, it can be concluded that the MEM analysis successfully visualizes the image of the two-dimensional nature in the h-BN crystal. Furthermore, the quantitative examination of the charge concentration at atomic sites in the MEM charge density provides experimental evidence of charge transfer from B atoms towards N atoms. © 1997 Elsevier Science Limited. All rights reserved.

  573. 金属内包フラーレンSc@C<SUB>82</SUB>結晶の構造

    西堀 英治, 高田 昌樹, 坂田 誠, 稲熊 正康, 篠原 久典

    日本結晶学会誌 39 25-25 1997年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.39.Supplement_25  

    ISSN:0369-4585

  574. MgベースLaves相合金の電子密度分布

    久保田 佳基, 高田 昌樹, 坂田 誠, 大庭 卓也, 木舩 弘一, 唯木 次男

    日本結晶学会誌 39 80-80 1997年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.39.Supplement_80  

    ISSN:0369-4585

  575. クリスタリット

    坂田 誠, 高田 昌樹, 百生 敦

    日本結晶学会誌 38 (4) 300-300 1996年8月30日

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.38.300  

    ISSN:0369-4585

  576. メタロフラーレンY@C_<82>

    高田 昌樹, 坂田 誠, 篠原 久典

    日本結晶学会誌 38 (3) 244-248 1996年6月30日

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.38.244  

    ISSN:0369-4585

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    The endohedral nature of the metallofullerene Y@C<SUB>82</SUB> is described based on recent results of the X-ray structural study for the metallofullerene Y@C<SUB>82</SUB> by the synchrotron powder diffraction experiment. For the structural analysis, the novel method which is the combination of the Rietveld analysis and the Maximum Entropy Method (MEM) is employed to analyse the complicated powder pattern. The obtained MEM charge density reveals that the yttrium atom is trapped within the carbon cage and reside very close to the fullerene cage indicating the strong off-centered nature of the Y@C<SUB>82</SUB> molecule.

  577. The nuclear density of YBCO by the maximum entropy method using neutron powder data

    Masaki Takata, Eiji Nishibori, Takashi Takayama, Makoto Sakata, Katsuaki Kodama, Masatoshi Sato, C. J. Howard

    Physica C: Superconductivity and its Applications 263 (1-4) 176-179 1996年5月

    DOI: 10.1016/0921-4534(96)00082-2  

    ISSN:0921-4534

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    In order to examine the nature of thermal motions of the YBCO superconductor, particularly in the CuO2 and CuO planes, the nuclear density distribution was observed by the maximum entropy method (MEM) using neutron powder diffraction data measured at 15 K. The characteristic squarish deformation of the nuclear density due to anharmonic thermal motion was found even at such a low temperature for the Cu atom in the CuO2 plane but not in the CuO plane. The obtained MEM nuclear density is consistent with the existence of strong Cu - O bonds in the CuO2 plane and not in the CuO plane.

  578. Direct observation of Pr-CuO<inf>2</inf> hybridization in PrBa<inf>2</inf>Cu<inf>3</inf>O<inf>7-δ</inf> by the MEM charge density study

    Masaki Takata, Takashi Takayama, Makoto Sakata, Satoshi Sasaki, Katsuaki Kodama, Masatoshi Sato

    Physica C: Superconductivity and its Applications 263 (1-4) 340-343 1996年5月

    DOI: 10.1016/0921-4534(96)80010-4  

    ISSN:0921-4534

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    In order to prove the existence of hybridization between the Pr and CuO2 conduction planes, a charge density study of PrBa2Cu3O6.87(PrBCO) and YBa2Cu3O6.97(YBCO) has been carried out by the maximum entropy method (MEM) using synchrotron radiation (SR) powder data. In the charge density of PrBCO obtained by MEM, there can be found directional robes of the charge density from the Pr atom toward the O atoms in the CuO2-planes. For YBCO there have not been observed appreciable charge densities in the interatomic region around the Y atom. The distinct difference of the charge densities between PrBCO and YBCO presents clear experimental evidence of the hybridization between Pr 4f-O 2pπ orbitals which supports the idea that the hole trapping by the hybridized states suppresses the superconductivity in PrBCO.

  579. The influence of the completeness of the data set on the charge density obtained with the maximum-entropy method. A re-examination of the electron-density distribution in Si

    Masaki Takata, Makoto Sakata

    Acta Crystallographica Section A: Foundations of Crystallography 52 (2) 287-290 1996年3月1日

    DOI: 10.1107/S0108767395014917  

    ISSN:0108-7673

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    The charge densities derived with the maximum-entropy method (MEM) may be influenced to some extent by the completeness of the data set. In order to examine the effects of the incompleteness, structure-factor data of Si measured by the Pendellösung method [Saka & Kato (1986). Acta Cryst. A42, 469-478] were re-analysed by the MEM. This data set is incomplete: it contains all space-group-allowed reflections with sinθ/λ = 0.86 Å-1, and in addition 844 and 880 with sinθ/λ = 1.04 Å-1. Results of a MEM analysis of the complete subset of data are compared with those from the full but incomplete set published previously [Sakata & Sato (1990). Acta Cryst. A46, 263-270]. The smaller but complete set was found to give a smooth charge-density distribution that is consistent with previous theoretical work. It is found that the sharp peak maximum at the bond midpoint reported previously is exaggerated owing to the highest-order reflection 880. The completeness of the data set appears to be one of the key factors for obtaining reliable charge densities with MEM. The incompleteness of the data set may cause non-physical fine features of the MEM density distribution.

  580. 金属内包フラーレンSc<SUB>2</SUB>@C<SUB>84</SUB>の構造について

    西堀 英治, 高田 昌樹, 坂田 誠, 山本 悦司, 篠原 久典

    日本結晶学会誌 38 139-139 1996年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.38.Supplement_139  

    ISSN:0369-4585

  581. CaSi<SUB>2</SUB>の電子密度分布

    佐宗 大介, 西堀 英治, 高田 昌樹, 坂田 誠, 今井 基晴

    日本結晶学会誌 38 40-40 1996年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.38.Supplement_40  

    ISSN:0369-4585

  582. Metallofullerenes: Their formation and characterization

    H. Shinohara, M. Takata, M. Sakata, T. Hashizume, T. Sakurai

    Materials Science Forum 232 207-232 1996年

    DOI: 10.4028/www.scientific.net/msf.232.207  

    ISSN:0255-5476

    eISSN:1662-9752

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    Endohedral metallofullerenes are novel forms of fullerene-related materials which encage metal atom(s) in a various size of fullerene cages. In the present article, recent advances on the production, separation (isolation) and various spectroscopic characterization of endohedral metallofullerenes are presented in an effort to clarify their structural and electronic properties. Endohedral metallofullerenes are produced by the DC arc-discharge method with metal/graphite composite rods as positive electrodes. The endohedral metallofullerenes, such as Y@C82 , Sc@C82, Sc2@C84 and Sc3@C82, have been purified and isolated by using the two-stage high performance liquid chromatography (HPLC). By using the purified metallofullerene samples, spectroscopic and structural features of the endohedral metallofullerenes are investigated. The ESR hyperfine splittings observed in the paramagnetic metallofullerenes such as Y@C82, Sc@C82 and Sc3@C82 can provide us information on electron transfer nature from the encaged metal atoms to the C82 fullerene cage. Direct STM imaging of the metallofullerenes on clean surfaces in an ultra-high vacuum environment shows that the endohedral metallofullerenes are stacked as close-packed arrays on the clean surfaces that uniform fcc (111) faces can be grown. Synchrotron X-ray diffraction study of Y@C82 can give us a direct structural evidence that the yttrium atom is encapsulated within the C82 cage. It shows that the encaged yttrium atom is not in the center of the cage but very close to the carbon network. The observed endohedral nature is consistent with the presence a strong electron transfer interaction between encaged atom(s) and fullerene cages.

  583. The principle of the maximum entropy method

    Makoto Sakata, Masaki Takata

    High Pressure Research 14 (4-5) 327-333 1996年

    ISSN:0895-7959

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    The theoretical background of the maximum entropy method (MEM) when it is applied to restore the electron or nuclear densities from diffraction data is described. In MEM, the concept of "entropy" is introduced to deal with any incompleteness in an observation in a proper way. An incompleteness causes some ambiguities in the results to some extent. The essence of the method is to find a solution which necessarily agrees with the observation, leaving the measure of ambiguities (entropy) maximum. A few results for simple structures with typical types of chemical bonding are also presented.

  584. Imaging of spin density in a crystal using polarized-neutron data and the Maximum-Entropy Method

    M. Takata, M. Takagi, T. Aono, M. Sakata

    Physica B: Physics of Condensed Matter 213-214 (C) 272-274 1995年8月1日

    DOI: 10.1016/0921-4526(95)00127-U  

    ISSN:0921-4526

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    In order to visualize the three-dimensional spin density in real space, the Maximum-Entropy Method (MEM) is applied to polarized-neutron data from Cs3CoCl5. The spin density obtained by the MEM shows the following features: most of the spin density is located at the Co site; the spin transfer from Co to Cl in the CoCl42- ions seems less significant; instead, the effect of the Cl- ligand on the spin-density distribution of Co is mainly on its anisotropy. A similar anisotropy is observed in the charge-density distribution obtained by the MEM, which suggested that the anisotropy in the Co spin density is due to electronic rather than magnetic interactions. © 1995 Elsevier Science B.V. All rights reserved.

  585. Nuclear and electron densities of anatase (TiO<inf>2</inf>)

    M. Sakata, M. Takagi, M. Takata, C. J. Howard

    Physica B: Physics of Condensed Matter 213-214 (C) 384-386 1995年8月1日

    DOI: 10.1016/0921-4526(95)00164-5  

    ISSN:0921-4526

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    The nuclear-density distribution of anatase (TiO2) is obtained from neutron powder-diffraction data by the maximum-entropy method (MEM). In MEM analysis, no structural model is required. The nuclear-density distribution indicates the smearing of nuclei by thermal motions, which is not necessarily harmonic. In order to show the complementarity of neutron and X-ray diffraction experiments in structural studies, the electron density distribution of anatase is also derived by the MEM. In comparison with the nuclear densities, the MEM electron-density distribution is more broadly distributed, which must represent the more wave-like nature of electrons. In addition, strong covalent bonding between the Ti and O atoms is evident. The thermal smearing may be intuitively understood in terms of the arrangement of the covalent bonds, i.e., isotropic thermal motions for Ti atoms which are octahedrally bonded to six O atoms, and anisotropic motion for the O atom which is bonded to three Ti atoms in a planar triangular configuration. For the O atoms, thermal vibrations perpendicular to the plane of the bonds, which involve bond bending but no bond compression, have the larger amplitudes. © 1995 Elsevier Science B.V. All rights reserved.

  586. Anharmonic thermal vibration of rutile determined from nuclear-density distribution by the maximum-entropy method

    S. Kumazawa, M. Takata, M. Sakata

    Physica B: Physics of Condensed Matter 213-214 (C) 387-389 1995年8月1日

    DOI: 10.1016/0921-4526(95)00165-6  

    ISSN:0921-4526

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    The anharmonic one-particle potential (OPP) parameters of rutile (TiO2) have been directly determined by least-squares refinement of the nuclear-density distribution, which is obtained by the maximum-entropy method (MEM) analysis using neutron powder-diffraction data. In order to construct an appropriate OPP model, the mean-square displacements of the MEM nuclear density are calculated and compared with that of OPP. From this comparison, it is concluded that the effective orders of OPP are fourth for the Ti atom and third for the O atom, respectively. Six fourth-order and three third-order anharmonic parameters were determined for the Ti and O atoms. No correlation problems between parameters were encountered in the analysis. © 1995 Elsevier Science B.V. All rights reserved.

  587. マキシマムエントロピー法によるY@C<SUB>82</SUB>の金属内包構造

    梅田 文太郎, 西堀 英治, 高田 昌樹, 坂田 誠, 大野 誠, 篠原 久典, 斉藤 弥八

    日本結晶学会誌 37 108-108 1995年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.37.Supplement_108  

    ISSN:0369-4585

  588. BaSi<SUB>2</SUB>の電子密度分布

    西堀 英治, 高田 昌樹, 坂田 誠, 熊沢 紳太郎, 今井 基晴

    日本結晶学会誌 37 12-12 1995年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.37.Supplement_12  

    ISSN:0369-4585

  589. Confirmation by X-ray diffraction of the endohedral nature of the metallofullerene Y@C<inf>82</inf>

    Masaki Takata, Buntaro Umeda, Eiji Nishibori, Makoto Sakata, Yahachi Saitot, Makoto Ohno, Hisanori Shinohara

    Nature 377 (6544) 46-49 1995年

    DOI: 10.1038/377046a0  

    ISSN:0028-0836

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    THE synthesis of fullerenes encapsulating various metal atoms within the carbon cage (endohedral metallofullerenes) has stimulated wide interest 1,2 because of their unusual structural and electronic properties. Most of the metallofullerenes prepared so far have been based on C82, and have incorporated lanthanum1,3-5, yttrium6,7, scandium8-10 and most of the lanthanide elements11,12'. Although there has been some debate about the endohedral nature of these compounds2,13,14, observations using scanning tunnelling microscopy15,16, extended X-ray absorption fine structure 17,18, transmission electron microscopy19 and electron spin resonance3,6-8,10 have strongly suggested that the metal atoms are indeed inside the fullerene cages; theoretical calculations20,21 also indicate that this is the case. But until now, no structural model has been derived experimentally to confirm the endohedral nature of the metallofullerenes. Here we report the results of a synchrotron X-ray powder diffraction study of Y@C82 that confirms that the yttrium atom is located within the carbon cage. The yttrium atom is displaced from the centre of the C82 molecule and is strongly bound to the carbon cage. © 1995 Nature Publishing Group.

  590. A direct investigation of thermal vibrations of beryllium in real space through the maximum‐entropy method applied to single‐crystal neutron diffraction data

    M. Takata, M. Sakata, S. Kumazawa, F. K. Larsen, B. B. Iversen

    Acta Crystallographica Section A 50 (3) 330-337 1994年5月

    DOI: 10.1107/S0108767393011523  

    ISSN:0108-7673

    eISSN:1600-5724

  591. Separation of two subsystems in ndi3fe46b4i composite crystal utilizing synchrotron radiation

    Takuya Ohba, Toru Hara, Satoshi Sasaki, Masaki Takata, Yukitomo Komura

    Japanese Journal of Applied Physics 32 (10 B) L1553-L1555 1993年10月

    DOI: 10.1143/JJAP.32.L1553  

    ISSN:0021-4922

    eISSN:1347-4065

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    The composite crystal, Ndi3Fe46B4i, was examined utilizing synchrotron radiation. Diffraction profiles along the c axis were measured at the wavelength of Nd and Fe absorption edges. It was clarified that two subsystems, Nd and Fe subsystems, contribute differently, and that the modulation periods of Nd and Fe are slightly different. The widths of peaks from Nd and Fe reveal that the fundamental period of the Nd subsystem fluctuates much more than that of the Fe subsystem. © 1993 The Japan Society of Applied Physics.

  592. MEED: A program package for electron-density-distribution calculation by the maximum-entropy method

    Shintaro Kumazawa, Yoshiki Kubota, Masaki Takata, Makoto Sakata, Yoshihiro Ishibashi

    Journal of Applied Crystallography 26 (pt 3) 453-457 1993年6月1日

    DOI: 10.1107/S0021889892012883  

    ISSN:0021-8898

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    MEED (maximum-entropy electron density) is a program package to calculate the electron-density distribution from a set of structure-factor data by the maximum-entropy method. MEED is an upgraded version of the original maximum-entropy program, MEMTARO, which was used in the first study to use the maximum-entropy method (MEM) on silicon [Sakata & Sato (1990). Acta Cryst. A46, 263-270]. MEED is applicable to any space group and can cope with both single-crystal and powder X-ray diffraction data, whereas MEMTARO can only after modification. Another upgraded feature is the speed of calculation. By employing a new algorithm, MEED is much faster than MEMTARO for the same calculation. Computing time depends on various factors, such as the number of reflection data, accuracy of data and the number of symmetry operations. It is estimated that MEED is typically 100 times faster than MEMTARO. In an extreme case like the beryllium powder-data case, MEED is 600 times faster than MEMTARO. MEED is coded in Fortran77 for both a scaler computer, FACOM M780, and a vector computer, FACOM VP2600, which are mainframe computers at the Computation Center of Nagoya University. MEED enables the electron-density distribution to be calculated for any crystalline material, with a fine pixel size, e.g. with 128×128×128 pixels to a unit cell, provided that accurate diffraction data are available. MEED can overcome, to some extent, one of the biggest drawbacks of MEM analysis, the vast computing time required.

  593. Maximum-entropy-method analysis of neutron diffraction data

    Makoto Sakata, Tatsuya Uno, Masaki Takata, Christopher J. Howard

    Journal of Applied Crystallography 26 (pt 2) 159-165 1993年4月

    DOI: 10.1107/S0021889892010793  

    ISSN:0021-8898

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    The maximum-entropy method (MEM) is a very powerful method for deriving accurate electron-density distributions from X-ray diffraction data. The success of the method depends on the fact that the electron density is always positive. In order to analyse neutron diffraction data by the MEM, it is necessary to overcome the difficulty of negative scattering lengths for some atoms, such as Ti and Mn. In this work, three approaches to the MEM analysis of neutron powder diffraction data are examined. The data, from rutile (TiO2), have been collected previously and analysed by the Reitveld method [Howard, Sabine & Dickson (1991. Acta Cryst. B47, 462-468]. The first approach is to add an artificial large constant to the scattering-length density to maintain that density positive, then to subtract the same constant at the completion of the MEM analysis. This approach, however, proves unsuccessful since unrealistic density distributions result. In the second approach, the observed structure factors are amended so that the sign of the contribution from the Ti atoms is reversed. This method produces plausible maps of scattering-length density but suffers the disadvantage that the observations must be corrected by a model-dependent calculated factor before the MEM analysis can proceed. The third approach is based not on a scattering-length densities but on nuclear densities, which are always positive. Two equations are obtained, one for atoms with nuclei of positive scattering length and the other for atoms with negative scattering length. From these two equations, the nuclear densities of Ti and O atoms can be calculated separately. This procedure, like its X-ray counterpart, requires no structural model. MEM analysis of the rutile data by this approach has been successfully completed. As expected, and in contrast to the electron-density distribution obtained by the MEM [Sakata, Uno, Takata & Mori (1992), Acta Cryst. B48, 591-598], the map shows both Ti and O nuclear densities localized in very small regions around the atomic centres. It is concluded that the MEM applied to neutron powder diffraction data is superior to conventional Fourier transformation and, in spite of the longer computation time, is very well worthwhile.

  594. The Electron Density Distribution in Be Metal Obtained from Synchrotron-Radiation Powder Data by the Maximum-Entropy Method

    Masaki Takata, Yoshiki Kubota, Makoto Sakata

    Zeitschrift fur Naturforschung - Section A Journal of Physical Sciences 48 (1-2) 75-80 1993年2月1日

    DOI: 10.1515/zna-1993-1-219  

    ISSN:0932-0784

    eISSN:1865-7109

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    The nature of the bonding in Be metal was studied by investigating the MEM map, which is the electron density distribution obtained by the Maximum-Entropy Method. In order to avoid extinction effects, 19 Bragg reflections were measured by a new powder-diffraction experiment that utilizes Synchrotron Radiation as an incident X-ray and an Imaging Plate as detector. The experiment was carried out at the Photon Factory BL6A2. In spite of the limited number of reflections used in the MEM analysis, the electron density distribution of Be was obtained accurately and reliably. The structure factors for unmeasured reflections were calculated and compared with the values observed by Larsen and Hansen [Acta Cryst. B40, 169 (1984)]. The agreement is very good. Furthermore, the MEM map revealed that Be metal forms an electronic layer in the shape of a honeycomb that is parallel to the basal plane. © 1993, Walter de Gruyter. All rights reserved.

  595. マキシマムエントロピー法より求めた核密度分布から非調和熱振動を解析する方法

    熊沢 紳太郎, 高田 昌樹, 坂田 誠

    日本結晶学会誌 35 39-39 1993年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.35.Supplement_39  

    ISSN:0369-4585

  596. Laves相合金MgCu<SUB>2</SUB>のMEMによる電子密度

    高田 昌樹, 久保田 佳基, 坂田 誠, 大庭 卓也, 小村 幸友

    日本結晶学会誌 35 51-51 1993年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.35.Supplement_51  

    ISSN:0369-4585

  597. The electronic layer of Mg found in the electron density distribution map obtained by the maximum entropy method

    Y. Kubota, M. Takata, M. Sakata

    Journal of Physics: Condensed Matter 5 (44) 8245-8254 1993年

    DOI: 10.1088/0953-8984/5/44/015  

    ISSN:0953-8984

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    The electron density distribution of HCP (hexagonal close-packed) metal Mg is obtained for the first time by the maximum entropy method (MEM). The data used in the analysis are measured by a newly developed synchrotron x-ray powder diffraction with an imaging plate (IP) as a detector. Care is taken in the quality of the specimen and the high counting statistics of the measurement. In the MEM map of Mg, which is the electron density distribution map obtained by the MEM, a surplus of electron charge is seen around the tetrahedral sites (T sites) of the HCP structure, while the electron densities around the octahedral sites (O sites) are much less than the average density of inter-atomic sites. By these surplus electrons, Mg metal forms a honeycomb network in the base plane and shows a kind of electronic layer structure. Since there are no ambiguities of phase determination, it can be said that the MEM map of Mg is constructed purely depending on the experimental data and free from any structural models. In our previous work the same kind of honeycomb network was found in Be, which is also an HCP metal. There is a high possibility that such honeycomb network is one of the structural characteristics of pure HCP metals at the electronic level. More work has to be done to investigate such a possibility and the MEM analysis will play an important role in structural studies at the electronic level.

  598. 特集 粉末回折法の新しい展開 7. 粉末回折法による電子密度分布

    坂田 誠, 高田 昌樹

    日本結晶学会誌 34 (2) 100-109 1992年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.34.100  

    ISSN:0369-4585

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    A recent progress of the Maximum Entropy Method to obtain a precise electron density distribution from X-ray powder diffraction data is reviewed. Results for rutile (TiO<SUB>2</SUB>), fcc metal Al and hcp metal Mg are given. In rutile case, apical and equatorial bonds of TiO<SUB>6</SUB> octahedra are visible in the MEM density map, which is the electron density map obtained by the Maximum Entropy Method. The nuclear density distribution of rutile is also shown, in which it is seen that the nuclear is localized only on the atomic site. The MEM map of Al looks to be well described by the nearly free electron model. On the other hand, in the case of Mg, the small electron density peaks are seen between three Mg atoms on the basal plane, on which electronic layers are formed in this subsatnce.

  599. 仮想X線顕微鏡の可能性

    坂田 誠, 高田 昌樹

    日本結晶学会誌 33 80-80 1991年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.33.Supplement_80  

    ISSN:0369-4585

  600. hcp金属の電子密度分布と層構造について

    高田 昌樹, 久保田 佳基, 坂田 誠

    日本結晶学会誌 33 56-56 1991年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.33.Supplement_56  

    ISSN:0369-4585

  601. C<SUB>60</SUB>の放射光による粉末X線回折

    久保田 佳基, 高田 昌樹, 坂田 誠, 原田 仁平, 斉藤 弥八, 篠原 久典, 永島 英夫, 安藤 義則

    日本結晶学会誌 33 55-55 1991年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.33.Supplement_55  

    ISSN:0369-4585

  602. The characterization of the (111) facet faces on the seed cone of [100] silicon single crystals grown by MCZ and CZ methods by X-ray CTR scattering

    J. Harada, T. Shimura, M. Takata, K. Yakushiji, K. Hoshi

    Journal of Crystal Growth 104 (4) 773-779 1990年9月

    DOI: 10.1016/0022-0248(90)90101-P  

    ISSN:0022-0248

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    The (111) facet faces on the seed cone of the [100] silicon single crystals grown by MCZ and CZ methods were characterized on an atomic scale by using X-ray CTR scattering. The natural (111) facet face of the MCZ single crystal was found to have a roughness of about three layers. This roughness is only very slightly inferior in comparison with that of the mechano-chemically polished (111) surface of a silicon wafer which has a roughness of two layers and is the flattest surface we have ever investigated. However, the (111) facet face of the usual CZ single crystal was so poor that the flatness could not be estimated. The effect of magnetic field on the crystal growth is discussed on the basis of these facts. © 1990.

  603. CdS microcrystal-doped silica glass prepared by the sol-gel process

    Masayuki Nogami, Katsumi Nagasaka, Masaki Takata

    Journal of Non-Crystalline Solids 122 (1) 101-106 1990年6月

    DOI: 10.1016/0022-3093(90)90231-A  

    ISSN:0022-3093

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    Glass of composition of 4.4CdO·95.6SiO2 was prepared by the sol-gel process from Si(OC2H5)4 and Cd(CH3COO)2·2H2O. CdS crystals were precipitated by exposing the glass of H2S gas, which were identified with hexagonal würtzite CdS crystals. From the X-ray diffraction analyses and transmission electron micrographs, these crystals were 2 to 6 nm in diameter. In the optical absorption spectra, the absorption edge exhibited a blue shift compared to that of the bulk CdS and its energy shift was reciprocally proportional to the square of the crystal size. Thus the quantum size effect could be found for the glass containing CdS prepared by the sol-gel process. © 1990.

  604. マキシマムエントロピー法による結晶内の電子密度分布

    坂田 誠, 高田 昌樹

    日本結晶学会誌 32 (3) 175-183 1990年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.32.175  

    ISSN:0369-4585

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    The Maximum Entropy Method to obtain Electron Density Distribution Map (EDDM) of crystals is outlined. In the method, the particular attention is paid to treat the powder diffraction data. By using the method, three-dimensional EDDM of silicon is drawn from the 30 structure fact ors determined accurately by Saka and Kato [T.Saka & N.Kato: Acta Cryst. <I>A42</I>, 468 (1986) ] . The EDDM of CeO<SUB>2</SUB> obtained from powder data is also shown. It is found that the EDDM drawn by the MEM can reveal details of electron density distribution in solid state such as chemical bonding and electrons in vacant sites.

  605. MEMによるhcp金属の電子密度分布の研究

    久保田 佳基, 高田 昌樹, 坂田 誠

    日本結晶学会誌 32 48-48 1990年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.32.Supplement_48  

    ISSN:0369-4585

  606. IPを検出器としたSRにおける粉末回折法

    山田 学, 高田 昌樹, 坂田 誠

    日本結晶学会誌 32 58-58 1990年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.32.Supplement_58  

    ISSN:0369-4585

  607. Electron-density distribution from x-ray powder data by use of profile fits and the maximum-entropy method

    M. Sakata, R. Mori, S. Kumazawa, M. Takata, H. Toraya

    Journal of Applied Crystallography 23 (6) 526-534 1990年

    DOI: 10.1107/S0021889890008214  

    ISSN:0021-8898

    eISSN:1600-5767

    詳細を見る 詳細を閉じる

    Following the profile decomposition of CeO2 X-ray powder data into individual structure factors, the maximum-entropy method (MEM) has been used to obtain an electron-density-distribution map. In the profile decomposition process, it is impossible to avoid the problems of overlapping peaks which have the same magnitude of reciprocal vectors, such as d*(511) and d* (333), for a cubic crystal, or very severely overlapping reflections. The formalism to treat such overlapping reflections in the MEM analysis is to introduce combined structure factors. The maximum value of the scattering vector, 4φ(sinθ)/δ, which was used in the present analysis is small (about 7-8 -1) but the resulting electrondensity- distribution map is of a high quality and much superior to the conventional map. As a consequence, the ionic charge of Ce and O ions can be obtained with reasonable accuracy from the MEM density map. Furthermore, the map reveals the existence of electrons around the supposedly vacant site surrounded by eight O atoms, which is probably related to the high ionic conductivity of this substance. © 1990 International Union of Crystallography.

  608. SiO<SUB>2</SUB>ガラス中のCdS微粒子について

    高田 昌樹, 久保田 佳基, 坂田 誠, 原田 仁平, 野上 正行

    日本結晶学会誌 31 PB-17-PB-17 1989年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.31.Supplement_PB-17  

    ISSN:0369-4585

  609. High resolution electron microscopy of partial dislocations in the Laves phase structure

    Y. Kitano, M. Takata, Y. Komura

    Journal of Microscopy 142 (2) 181-190 1986年5月

    DOI: 10.1111/j.1365-2818.1986.tb02755.x  

    ISSN:0022-2720

    eISSN:1365-2818

    詳細を見る 詳細を閉じる

    A Mg‐base Laves phase was investigated by high resolution electron microscopy (HREM). Linear defects found at terminations of stacking faults were classified into three groups. The first is a partial dislocation at a termination of a stacking fault, the second is a superposed partial dislocation which is defined as a defect produced by a superposition of terminations of two or more stacking faults lying on neighbouring layers, and the third is a combined linear defect which consists of a characteristic combination of terminations of stacking faults. In the last case the total stacking fault vector becomes equal to the translation vector in the basal plane, so that the defect needs no relaxation of the lattice. The Burgers vectors of the partial dislocations were estimated with the aid of modified Burgers circuits. 1986 Blackwell Science Ltd

  610. 110.

    Masaki Takata, Yasuyuki Kitano, Yukitomo Komura

    Transactions of the Japan Institute of Metals, Supplement 27 261-268 1986年

    詳細を見る 詳細を閉じる

    A densely packed plane boundary between two adjoining crystals of the 2H structure in Mg(Cu,Al)//2 is investigated by high resolution electron microscopy. A CSL model is applied to the boundary structure. In this study, the origins of each layer of the 2H structure are taken as lattice points in drawing CSL. The new CSL obtained here is successfully used to investigate a structural model of the boundary, as well as to determine a Burgers vector of a DSC dislocation at a boundary step.

  611. Defect Structures in the Mg-base Laves Phase Mg(Cu0.08Zn0.92)2 査読有り

    Y. Komura, S. Takeda, M. Takata

    Transactions of the Japan Institute of Metals 24 (6) 413-420 1983年

    DOI: 10.2320/matertrans1960.24.413  

    ISSN:0021-4434

    詳細を見る 詳細を閉じる

    Analysis has been carried out by computer simulation. Two kinds of twinning structure on the (001) plane have been revealed, one of which is written as (hhc)h(chh) by the c-h order of the compound layers and the other is written as (hhc)hhh(chh). Characteristic line defects have been found on the (101) plane of the hexagonal cell of the obverse structure with stacking sequence ABC prime BCA prime CAB prime and on the (102) plane of the reverse structure AB prime A prime CA prime C prime BC prime B prime . A structural model for the middle part of the (102) line defect is proposed.

︎全件表示 ︎最初の5件までを表示

MISC 278

  1. 最新の放射光X線解析に基づくゴム材料の構造解析(II)実用例を中心として 極小角X線散乱と逆モンテカルロ法を用いた延伸過程でのゴム中シリカ粒子の分散状態の評価

    仲谷友孝, 小原真司, 星野大樹, 藤波想, 高田昌樹, 高田昌樹, 高田昌樹

    日本ゴム協会誌 92 (4) 2019年

    ISSN:0029-022X

  2. 水素・燃料電池戦略における研究支援基盤としての東北放射光計画

    渡邉 真史, 虻川 匡司, 矢代 航, 江島 丈雄, 小田島 肇, 高田 昌樹

    燃料電池 17 (3) 56-63 2018年

    出版者・発行元:燃料電池開発情報センター

    ISSN:1346-6623

  3. X線光子相関分光測定によるソフト界面ダイナミクス研究

    星野大樹, 星野大樹, 平井智康, 高原淳, 高田昌樹, 高田昌樹

    放射光 30 (3) 2017年

    ISSN:0914-9287

  4. 24aPS-71 放射光X線超精密構造解析による3d軌道秩序の観測手法の開発

    藤井 達也, 菅原 健人, 樋口 貴文, 片山 尚幸, 澤 博, 獅子堂 達也, 杉本 邦久, 高田 昌樹, 有馬 孝尚, 田口 康二郎, 十倉 好紀

    日本物理学会講演概要集 70 (0) 2422-2422 2015年

    出版者・発行元:一般社団法人 日本物理学会

    DOI: 10.11316/jpsgaiyo.70.1.0_2422  

    ISSN:2189-079X

  5. 9aPS-43 バナジウムスピネル酸化物Fe_<1-x>Mg_xV_2O_4の構造・磁気相転移II(9aPS 領域8ポスターセッション(遷移金属酸化物・鉄砒素系など),領域8(強相関系))

    三木 郁也, 石橋 広記, 河口 彰吾, 杉本 邦久, 加藤 健一, 高田 昌樹, 久保田 佳基

    日本物理学会講演概要集 69 (2) 413-413 2014年8月22日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  6. 9aPS-50 バナジウムスピネル酸化物FeV_2O_4のt_<2g>軌道に対する軌道希釈効果(9aPS 領域8ポスターセッション(遷移金属酸化物・鉄砒素系など),領域8(強相関系))

    長見 和樹, 石橋 広記, 河口 彰吾, 杉本 邦久, 加藤 健一, 高田 昌樹, 久保田 佳基

    日本物理学会講演概要集 69 (2) 414-414 2014年8月22日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  7. 9aPS-47 コランダム型遷移金属酸化物(V_<1-x>Fe_x)_2O_3の結晶構造と電気的・磁気的特性(9aPS 領域8ポスターセッション(遷移金属酸化物・鉄砒素系など),領域8(強相関系))

    吉田 健, 石橋 広記, 河口 彰吾, 杉本 邦久, 加藤 健一, 高田 昌樹, 久保田 佳基

    日本物理学会講演概要集 69 (2) 414-414 2014年8月22日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  8. 29pAS-3 サイクロイド型らせん磁性体CrB_2の放射光X線磁気回折測定(29pAS 遍歴磁性・化合物磁性,領域3(磁性))

    大隅 寛幸, 竹下 聡史, Tardif Samuel, 有馬 孝尚, 高田 昌樹, 高阪 勇輔, 秋光 純

    日本物理学会講演概要集 69 (1) 528-528 2014年3月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  9. 強相関系物質ヘテロ構造観察のための集光放射光X線顕微回折装置の開発

    竹下聡史, 大隅寛幸, TARDIF Samuel, 有馬孝尚, 有馬孝尚, 高田昌樹, 高田昌樹, 湯本博勝, 小山貴久, 大橋治彦

    日本物理学会講演概要集 69 (1) 2014年

    ISSN:1342-8349

  10. ケージ内ゲスト原子の運動がもたらす熱伝導の低下の理解

    谷垣勝己, 藤原明比古, 杉本邦久, 田中宏志, 高田昌樹

    日本結晶学会誌 55 (2) 142-152 2013年4月1日

    DOI: 10.5940/jcrsj.55.142  

  11. 27aXY-7 Pr_<0.5>Ca_<0.5>MnO_3/La_<0.5>Sr_<0.5>MnO<3>超格子薄膜における電荷秩序ドメインと電気伝導(27aXY Mn酸化物他(電荷秩序・軌道秩序・CMRなど),領域8(強相関系:高温超伝導,強相関f電子系など))

    竹下 聡史, 大隅 寛幸, Tardif Samuel, 有馬 孝尚, 高田 昌樹, 中村 優男, 久保田 将司, 川崎 雅司, 十倉 好紀, 湯本 博勝, 小山 貴久, 大橋 治彦

    日本物理学会講演概要集 68 (1) 604-604 2013年3月26日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  12. 27aPS-122 K_2NiF_4型Sr_2VO_4におけるoffstoichiometryと軌道整列(27aPS 領域8ポスターセッション(磁性,低温1),領域8(強相関系:高温超伝導,強相関f電子系など))

    植野 卓嗣, 金 廷恩, 高田 昌樹, 勝藤 拓郎

    日本物理学会講演概要集 68 (1) 638-638 2013年3月26日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  13. 高速高密度相変化記録材料の原子配列と相変化過程の解明

    松永 利之, 児島 理恵, 山田 昇, 小原 真司, 高田 昌樹

    まてりあ : 日本金属学会会報 52 (2) 49-57 2013年2月1日

    出版者・発行元:The Japan Institute of Metals and Materials

    DOI: 10.2320/materia.52.49  

    ISSN:1340-2625

  14. Pr<sub>0.5</sub>Ca<sub>0.5</sub>MnO<sub>3</sub>/La<sub>0.5</sub>Sr<sub>0.5</sub>MnO<sub>3</sub>超格子薄膜における電荷秩序ドメインと電気伝導

    竹下聡史, 大隅寛幸, TARDIF Samuel, 有馬孝尚, 有馬孝尚, 高田昌樹, 高田昌樹, 中村優男, 久保田将司, 久保田将司, 川崎雅司, 川崎雅司, 十倉好紀, 十倉好紀, 湯本博勝, 小山貴久, 大橋治彦

    日本物理学会講演概要集 68 (1) 2013年

    ISSN:1342-8349

  15. 26pYH-7 非整合な電荷密度波を示すスピネル硫化物CuV_2S_4の結晶構造解析と軌道整列(26pYH V酸化物・秩序型ペロブスカイト,領域8(強相関系:高温超伝導,強相関f電子系など))

    河口 彰吾, 久保田 佳基, 辻 成希, 金 廷恩, 加藤 健一, 高田 昌樹, 石橋 広記

    日本物理学会講演概要集 67 (1) 676-676 2012年3月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  16. 24aCL-9 Bi_2SiO_5強誘電体の構造相転移による機能構造変化(24aCL 誘電体(酸化物,ペロヴスカイト,光散乱),領域10(誘電体,格子欠陥,X線・粒子線,フォノン))

    金 栄勲, 金 廷恩, 田中 宏志, 杉本 邦久, 谷口 博基, 金 聖雄, 加藤 健一, 伊藤 満, 細野 秀雄, 高田 昌樹

    日本物理学会講演概要集 67 (1) 985-985 2012年3月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  17. 24pYD-1 新元素戦略が拓くサイエンスと物理学会の役割 : 京、J-PARC、SPring-8/SACLA大型研究基盤ツールとの協奏的研究(24pYD 領域8,領域3,領域4,領域7,領域9,領域10合同シンポジウム:物理学における新・元素戦略,領域8(強相関系:高温超伝導,強相関f電子系など))

    高田 昌樹

    日本物理学会講演概要集 67 (1) 561-561 2012年3月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  18. Bi<sub>2</sub>SiO<sub>5</sub>における新規な強誘電性の発現機構

    谷口博基, 細野秀雄, 伊藤満, 桑原彰秀, 森分博紀, KIM Jungeun, KIM Younghun, KIM Sungwng, 星山卓也, 小山司, 森茂生, 高田昌樹, 高田昌樹, 稲熊宜之

    日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM) 25th 2012年

  19. SPring-8分光分析ビームライン37XUのアップグレードと走査型X線顕微鏡の現状

    寺田靖子, 湯本博勝, 小山貴久, 山崎裕史, 仙波泰徳, 竹内智之, 竹下邦和, 成山展照, 松下智裕, 宇留賀朋哉, 藤原明比古, 大橋治彦, 後藤俊治, 山本雅貴, 高田昌樹, 石川哲也, 寺田靖子, 湯本博勝, 小山貴久, 山崎裕史, 仙波泰徳, 竹内智之, 竹下邦和, 成山展照, 松下智裕, 宇留賀朋哉, 大橋治彦, 後藤俊治, 山本雅貴, 高田昌樹, 石川哲也

    日本放射光学会年会・放射光科学合同シンポジウム予稿集 25th 2012年

  20. 21aGC-7 LnT_2Al_<10>の電子密度分布(21aGC Cel-2-10,領域8(強相関系:高温超伝導,強相関f電子系など))

    世良 正文, 田中 大貴, 谷田 博司, 小川 真由子, 森吉 千佳子, 黒岩 芳弘, 西岡 孝, 松村 政博, 金 延恩, 辻 成希, 高田 昌樹

    日本物理学会講演概要集 66 (2) 456-456 2011年8月24日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  21. 21aGD-7 三量体相転移を示すBaV_<10>O_<15>の放射光静電ポテンシャル解析(21aGD バナジウム酸化物,領域8(強相関系:高温超伝導,強相関f電子系など))

    川邉 直輝, 加藤 健一, 勝藤 拓郎, 田中 宏志, 高田 昌樹

    日本物理学会講演概要集 66 (2) 459-459 2011年8月24日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  22. 22pGK-2 異常高原子価鉄ペロブスカイトLn^<3+>Cu_3Fe_4O_<12>におけるAサイト置換効果(22pGK 鉄酸化物,領域8(強相関系:高温超伝導,強相関f電子系など))

    恵谷 英宜, 山田 幾也, 大串 研也, 林 直顕, 土田 一貴, 金 廷恩, 辻 成希, 草野 圭弘, 高橋 亮治, 西山 宣正, 井上 徹, 入舩 徹男, 加藤 健一, 高田 昌樹, 高野 幹夫

    日本物理学会講演概要集 66 (2) 541-541 2011年8月24日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  23. 22pGK-1 異常高原子価鉄ペロブスカイトSrCu_3Fe_4O_<12>における電荷移動・電荷不均化(22pGK 鉄酸化物,領域8(強相関系:高温超伝導,強相関f電子系など))

    山田 幾也, 土田 一貴, 大串 研也, 林 直顕, 金 廷恩, 辻 成希, 草野 圭弘, 高橋 亮治, 西山 宣正, 井上 徹, 入舩 徹男, 加藤 健一, 高田 昌樹, 高野 幹夫, Etani H.

    日本物理学会講演概要集 66 (2) 540-540 2011年8月24日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  24. 22pGK-7 LuFe_2O_4の放射光X線磁気回折測定II(22pGK 鉄酸化物,領域8(強相関系:高温超伝導,強相関f電子系など))

    大隅 寛幸, 竹下 聡史, 有馬 孝尚, 高田 昌樹, 赤浜 裕士, 神戸 高志, 狩野 旬, 永田 知子, 池田 直

    日本物理学会講演概要集 66 (2) 542-542 2011年8月24日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  25. 21aPS-111 三角格子反強磁性体PdCrO_2の導電性と磁気秩序(21aPS 領域3ポスターセッション,領域3(磁性,磁気共鳴))

    高津 浩, 門脇 広明, 吉沢 英樹, Broholm Collin, Zhao Yang, Green Mark, 米澤 進吾, 前野 悦輝, 金 廷恩, 辻 成希, 高田 昌樹

    日本物理学会講演概要集 66 (2) 398-398 2011年8月24日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  26. 24aGB-6 擬三角格子系Ba_2Ti_<13>O_<22>の相転移と異常物性(24aGB 遷移金属化合物磁性・磁気構造,領域8(強相関系:高温超伝導,強相関f電子系など))

    孝山 康太, 星野 真寿美, 佐藤 拓也, 加藤 健一, 高田 昌樹, 小山 司, 森 茂生, 勝藤 拓郎

    日本物理学会講演概要集 66 (2) 632-632 2011年8月24日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  27. 22pTD-3 クラスレートのラットリングと熱伝導の相関に対する静電ポテンシャル解析を用いた定量評価(22pTD クラスレート系,領域7(分子性固体・有機導体))

    藤原 明比古, 杉本 邦久, Shih Che-Hsiu, 田中 宏志, Tang Jun, 田邉 洋一, Xu Jingtao, 平郡 諭, 谷垣 勝己, 高田 昌樹

    日本物理学会講演概要集 66 (2) 867-867 2011年8月24日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  28. 28pEF-1 異常高原子価Feペロブスカイトの構造・物性(28pEF 遷移金属酸化物(中性子・X線・粒子線),領域8(強相関係:高温超伝導,強相関f電子系など))

    山田 幾也, 土田 一貴, 恵谷 英宜, 大串 研也, 林 直顕, 金 廷恩, 辻 成希, 高橋 亮治, 西山 宣正, 井上 徹, 入舩 徹男, 加藤 健一, 高田 昌樹, 高野 幹夫

    日本物理学会講演概要集 66 (1) 683-683 2011年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  29. 25aPS-37 MFIゼオライトに吸着した酸素分子の磁性と配列構造(25aPS-3 領域3ポスターセッション,領域3(磁性,磁気共鳴))

    堀 彰宏, 鰐川 泰, 久保田 佳基, 桑名 加菜子, 小林 達生, 松尾 晶, 金道 浩一, 白曼 雅子, 仲井 和之, 金 延恩, 加藤 健一, 高田 昌樹, 松田 亮太郎, 北川 進

    日本物理学会講演概要集 66 (1) 464-464 2011年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  30. 25pEF-10 LuFe_2O_4の放射光X線磁気回折測定(25pEF マンガン系物資(マンガン酸化物・マルチフェロイック物質),領域8(強相関系:高温超伝導,強相関f電子系など))

    大隅 寛幸, 竹下 聡史, 有馬 孝尚, 高田 昌樹, 赤浜 裕士, 神戸 高志, 狩野 旬, 永田 知子, 池田 直

    日本物理学会講演概要集 66 (1) 561-561 2011年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  31. 25pEF-11 集光放射光で見たLuFe_2O_4の電荷秩序ドメイン(25pEF マンガン系物資(マンガン酸化物・マルチフェロイック物質),領域8(強相関系:高温超伝導,強相関f電子系など))

    竹下 聡史, 大隅 寛幸, 有馬 孝尚, 高田 昌樹, 赤浜 裕士, 神戸 高志, 狩野 旬, 永田 知子, 池田 直, 湯本 博勝, 小山 貴久, 大橋 治彦

    日本物理学会講演概要集 66 (1) 561-561 2011年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  32. 27pEC-9 RuおよびRhパイクロア型酸化物の金属絶縁体転移と構造相転移(27pEC 幾何学的フラストレーション,領域8(強相関係:高温超伝導,強相関f電子系など))

    山本 文子, 高木 英典, 橋爪 大輔, 加藤 健一, 高田 昌樹, 神山 崇, 鳥居 周輝, 石垣 徹

    日本物理学会講演概要集 66 (1) 632-632 2011年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  33. 26pPSA-39 Aサイト秩序型ペロブスカイトYCu_3Fe_4O_<12>の超高圧合成・構造・物性(26pPSA 領域8ポスターセッション(低温2),領域8(強相関係:高温超伝導,強相関f電子系など))

    恵谷 英宜, 山田 幾也, 大串 研也, 林 直顕, 土田 一貴, 金 廷恩, 辻 成希, 高橋 亮治, 西山 宣正, 井上 徹, 入舩 徹男, 加藤 健一, 高田 昌樹, 高野 幹夫

    日本物理学会講演概要集 66 (1) 627-627 2011年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  34. 25aTJ-5 静電ポテンシャル解析によるクラスレート結晶のラットリング運動可視化と定量評価(25aTJ 籠状物質(クラスレート化合物),領域7(分子性固体・有機導体))

    藤原 明比古, 杉本 邦久, Shih Che-Hsiu, 田中 宏志, Tang Jun, 田邉 洋一, Xu Jingtao, 平郡 諭, 谷垣 勝己, 高田 昌樹

    日本物理学会講演概要集 66 (1) 846-846 2011年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  35. 25aEG-8 PbO-SiO_2ガラスのネットワーク構造II(25aEG 液体金属,領域6(金属,超低温,超伝導・密度波))

    小原 真司, 大野 英雄, 高田 昌樹, 臼杵 毅, 森田 秀利, 鈴谷 賢太郎, Akola Jaakko, Pusztai Laszlo

    日本物理学会講演概要集 66 (1) 807-807 2011年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  36. スピン・電荷・軌道秩序ドメイン観察のための集光X線を利用した走査型顕微回折計の開発

    竹下聡史, 大隅寛幸, 有馬孝尚, 伊藤基巳紀, 田中義人, 高田昌樹, 高田昌樹, 湯本博勝, 小山貴久, 大橋治彦, 大橋治彦

    日本放射光学会年会・放射光科学合同シンポジウム予稿集 24th 2011年

  37. ナノスケール分析ステーションのための高フラックス・高安定ナノ集光ビームラインの基盤整備

    湯本博勝, 湯本博勝, 小山貴久, 小山貴久, 山崎裕史, 山崎裕史, 仙波泰徳, 仙波泰徳, 竹内智之, 竹内智之, 竹下邦和, 竹下邦和, 成山展照, 成山展照, 松下智裕, 松下智裕, 寺田靖子, 寺田靖子, 鈴木基寛, 鈴木基寛, 河村直己, 河村直己, 水牧仁一朗, 水牧仁一朗, 宇留賀朋哉, 宇留賀朋哉, 大橋治彦, 大橋治彦, 後藤俊治, 後藤俊治, 山本雅貴, 山本雅貴, 高田昌樹, 高田昌樹, 石川哲也, 石川哲也

    精密工学会大会学術講演会講演論文集 2011 (0) 477-478 2011年

    出版者・発行元:公益社団法人 精密工学会

    DOI: 10.11522/pscjspe.2011A.0.477.0  

    詳細を見る 詳細を閉じる

    グリーン・ナノテク研究支援のための放射光分析基盤として,SPring-8においてナノスケール集光ビームを安定に利用できる蛍光X線分析(BL37XU)及びナノXAFS (BL39XU)ステーションを2010年度に整備した.高フラックス,高安定ナノビームの汎用化を目指しビームライン全体を最適化し,光学系や装置開発を行った結果,2011年4月に安定な100nm集光ビームを実現した.

  38. New insights into the polymerization and structural mechanisms of the polydiacetylene DCHD: an X-ray/MEM study

    Bagautdin Bagautdinov, Hiroshi Tanaka, Che-Hsiu Shih, Kunihisa Sugimoto, Sono Sasaki, Kohji Tashiro, Masaki Takata

    ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 67 C27-C28 2011年

    出版者・発行元:INT UNION CRYSTALLOGRAPHY

    DOI: 10.1107/S0108767311099430  

    ISSN:2053-2733

  39. SPring-8 BL37XUにおけるナノプローブの実現と走査型X線顕微鏡への応用

    寺田靖子, 湯本博勝, 小山貴久, 山崎裕史, 仙波泰徳, 竹内智之, 竹下邦和, 成山展照, 松下智裕, 宇留賀朋哉, 藤原明比古, 大橋治彦, 後藤俊治, 山本雅貴, 高田昌樹, 石川哲也

    X線分析討論会講演要旨集 47th 2011年

  40. Identification of mineral in thin section by energy-Scanning X-ray diffraction

    Kenji Hagiya, Takashi Mikouchi, Michael E. Zolensky, Katherine Joy, Kazumasa Ohsumi, Yasuko Terada, Naoto Yagi, Masaki Takata

    ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 67 C809-C809 2011年

    出版者・発行元:INT UNION CRYSTALLOGRAPHY

    DOI: 10.1107/S0108767311079505  

    ISSN:2053-2733

  41. 無容器法から合成されたバルク酸化物ガラス (特集 ガラスの構造)

    小原 真司, 高田 昌樹, 鈴谷 賢太郎

    New glass 25 (4) 3-6 2010年12月

    出版者・発行元:ニュ-ガラスフォ-ラム

    ISSN:0914-6563

  42. 23aRC-8 The photo-induced commensurate modulated structure in site selective spin crossover complex trans-[Fe(abpt)_2(NCS)_2].

    Shih Che-Hsiu, Sheu Chou-Fu, Kato Kenichi, Sugimoto Kunihisa, Kim Jungeun, Wang Yu, Takata Masaki

    日本物理学会講演概要集 65 (2) 670-670 2010年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  43. 26aRL-9 電荷移動錯体TTF-CAの中性イオン性転移に伴う分子間相互作用の変化(26aRL 分子性固体・中性-イオン性転移,領域7(分子性固体・有機導体))

    河 宣如, 加藤 健一, 田中 宏志, 金 廷恩, 高田 昌樹, Gercia P., Dahaoui S., Lecomte C.

    日本物理学会講演概要集 65 (2) 832-832 2010年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  44. 26aWL-9 MFIゼオライトに吸着した酸素分子の配列構造(26aWL 量子スピン(クラスター系),領域3(磁性,磁気共鳴))

    鰐川 泰, 久保田 佳基, 堀 彰宏, 桑名 加菜子, 小林 達生, 白曼 雅子, 仲井 和之, 金 廷恩, 加藤 健一, 高田 昌樹, 松田 亮太郎, 北川 進

    日本物理学会講演概要集 65 (2) 448-448 2010年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  45. 23pWB-14 放射光を用いたスピネル酸化物FeV_2O_4の単結晶構造解析(23pWB V酸化物,領域8(強相関系:高温超伝導,強相関f電子系など))

    新居 陽一, 佐賀山 基, 有馬 孝尚, 酒井 理宇, 青柳 忍, 西堀 英治, 澤 博, 杉本 邦久, 大隅 寛幸, 高田 昌樹

    日本物理学会講演概要集 65 (2) 500-500 2010年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  46. 26pWJ-3 CeT_2Al_<10>(T=Fe,Ru,Os)の格子定数と結晶構造(26pWJ Cel-2-10系,領域8(強相関系:高温超伝導,強相関f電子系など))

    世良 正文, 田中 大貴, 谷田 博司, 森吉 千佳子, 小川 真由子, 黒岩 芳弘, 西岡 孝, 小林 理気, 松村 政博, 高田 昌樹, 金 延恩, 辻 成希

    日本物理学会講演概要集 65 (2) 630-630 2010年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  47. 26aWH-7 フッ素ドープLaFeAsOの静電ポテンシャル可視化による構造物性の研究(26aWH 鉄砒素系超伝導(中性子,X線,粒子線,分光),領域8(強相関系:高温超伝導,強相関f電子系など))

    澤田 智博, 金 廷恩, 杉本 邦久, 加藤 健一, 石角 元志, 社本 真一, 高田 昌樹

    日本物理学会講演概要集 65 (2) 616-616 2010年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  48. 第23回放射光学会年会・放射光科学合同シンポジウムを終えて

    高田 昌樹

    放射光 23 (2) 101-102 2010年3月31日

    ISSN:0914-9287

  49. 22pPSA-36 MFIゼオライトに吸着した酸素分子の配列構造(22pPSA 領域3ポスターセッション(酸化物・f電子系磁性・スピングラス・量子スピン・フラストレーション系・実験技術・磁性一般),領域3(磁性,磁気共鳴))

    鰐川 泰, 久保田 佳基, 堀 彰宏, 桑名 加菜子, 小林 達生, 白曼 雅子, 仲井 和之, 金 廷恩, 加藤 健一, 高田 昌樹, 松田 亮太郎, 北川 進

    日本物理学会講演概要集 65 (1) 506-506 2010年3月1日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  50. 20aGF-2 らせん磁性体SrFeO_3における多段相転移とX線磁気散乱(20aGF マルチフェロイクス1,領域8(強相関系:高温超伝導,強相関f電子系など))

    竹下 聡史, 徳田 哲久, 大隅 寛幸, 有馬 孝尚, 高田 昌樹, 石渡 晋太郎, 田口 康二郎, 金子 良夫, 十倉 好紀

    日本物理学会講演概要集 65 (1) 532-532 2010年3月1日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  51. 22pEF-8 多孔性配位高分子Cu-CHDに吸着した酸素分子の磁性と構造の相関(22pEF 量子スピン系・スピングラス,領域3(磁性,磁気共鳴))

    堀 彰宏, 小林 達生, 久保田 佳基, 松尾 晶, 金道 浩一, 金 延恩, 加藤 健一, 高田 昌樹, 坂本 裕俊, 松田 亮太郎, 北川 進

    日本物理学会講演概要集 65 (1) 482-482 2010年3月1日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  52. 21aGE-13 A_2V_<13>O_<22>(A=Sr,Ba)の三量体形成を伴った構造相転移(21aGE Ti・V酸化物,領域8(強相関系:高温超伝導,強相関f電子系など))

    宮崎 潤野, 金 廷恩, 加藤 健一, 高田 昌樹, 勝藤 拓郎

    日本物理学会講演概要集 65 (1) 596-596 2010年3月1日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  53. 放射光結晶化学研究における時分割測定と極微小結晶構造解析の将来展望

    安田伸広, 福山祥光, 木村滋, 鳥海幸四郎, 田中義人, 守友浩, 高田昌樹

    日本結晶学会年会講演要旨集 2010 20 2010年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.52.s20  

    ISSN:0369-4585

  54. 20aHS-9 円偏光X線マイクロビームを用いたCsCuCl_3中のカイラルドメインの観察(20aHS X線・粒子線(X線),領域10(誘電体,格子欠陥,X線・粒子線,フォノン))

    大隅 寛幸, 中尾 裕也, 横堀 利夫, 松井 秀樹, 秋光 純, 徳田 哲久, 竹下 聡史, 有馬 孝尚, 高田 昌樹, 鈴木 基寛, 河村 直己, 高橋 功, 高阪 勇輔

    日本物理学会講演概要集 65 (0) 968-968 2010年

    出版者・発行元:一般社団法人 日本物理学会

    DOI: 10.11316/jpsgaiyo.65.1.4.0_968_3  

    ISSN:1342-8349

  55. Direct visualization of disordered polymer chain structure in polyoxymethylene crystal by MEM.

    Kunihisa Sugimoto, Sono Sasaki, Kohji Tashiro, Yoshie Nakamura, Masaki Takata

    ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 66 S283-S284 2010年

    出版者・発行元:INT UNION CRYSTALLOGRAPHY

    DOI: 10.1107/S0108767310093529  

    ISSN:2053-2733

  56. 反応現象のX線ピンポイント構造計測 : DVD材料の光記録現象をSPring-8で見る

    木村 滋, 田中 義人, 山田 昇, 高田 昌樹

    放射光 22 (5) 231-240 2009年9月30日

    出版者・発行元:日本放射光学会

    ISSN:0914-9287

  57. 28aYK-13 熱振動を考慮したMEM静電ポテンシャル解析(X線・粒子線(X線),領域10,誘電体,格子欠陥,X線・粒子線,フォノン物性)

    井上 充, 田中 宏志, 黒岩 芳弘, 森吉 千佳子, 高田 昌樹

    日本物理学会講演概要集 64 (2) 894-894 2009年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  58. 28aYK-12 GPUによるMEM電子密度解析の高速化(X線・粒子線(X線),領域10,誘電体,格子欠陥,X線・粒子線,フォノン物性)

    服部 知典, 田中 宏志, 高田 昌樹

    日本物理学会講演概要集 64 (2) 894-894 2009年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  59. 27aRK-13 MgV_2O_4の軌道秩序(パイロクロア,V酸化物,領域8,強相関系:高温超伝導,強相関f電子系など)

    新高 誠司, 大隈 寛幸, 杉本 邦彦, 橋爪 大輔, 加藤 健一, 有馬 孝尚, 高田 昌樹, 高木 英典

    日本物理学会講演概要集 64 (2) 535-535 2009年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  60. 27aRL-7 非共鳴円偏光X線回折によるスピンカイラリティの観測(マルチフェロイクス2,領域8,強相関系:高温超伝導,強相関f電子系など)

    佐賀山 基, 谷口 耕治, 阿部 伸行, 有馬 孝尚, 奥山 大輔, 山崎 裕一, 十倉 好紀, 酒井 創一朗, 森田 健士, 米須 尚, 大隈 寛幸, 高田 昌樹

    日本物理学会講演概要集 64 (2) 537-537 2009年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  61. 27aRK-11 擬三角格子系BaV_<13>O_<18>の新奇相転移(パイロクロア,V酸化物,領域8,強相関系:高温超伝導,強相関f電子系など)

    池田 美穂, 金 廷恩, 加藤 健一, 高田 昌樹, 永峰 佑起, 森 茂生, 勝藤 拓郎

    日本物理学会講演概要集 64 (2) 535-535 2009年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  62. 28aYC-12 Photo-induced spin transition and linkage isomerism electron density study by MEM

    施 哲修, 許 朝富, 杉本 邦久, 金 廷恩, 加藤 健一, 王 瑜, 高田 昌樹

    日本物理学会講演概要集 64 (2) 787-787 2009年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  63. 27pPSA-20 多孔性金属錯体Cd(bpndc)(bpy)に吸着した酸素分子の整列構造と磁性II(領域3ポスターセッション(量子スピン系・フラストレーション系等),領域3,磁性,磁気共鳴)

    宮村 真理子, 南方 千晴, 鰐川 泰, 久保田 佳基, 堀 彰宏, 戸田 洋平, 小林 達生, 松尾 晶, 金道 浩一, 高田 昌樹, 田中 大輔, 北川 進

    日本物理学会講演概要集 64 (2) 385-385 2009年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  64. 25aYD-3 結晶水制御したしアノ錯体の静電ポテンシャル変化(クラスレート・ゼオライト,領域7,分子性固体・有機導体)

    金 廷恩, 田中 宏志, 加藤 健一, 高田 昌樹, 守友 浩

    日本物理学会講演概要集 64 (2) 733-733 2009年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  65. 25aRG-6 ペロブスカイト型RTiO_3における磁性と高温格子異常(Ti,V酸化物,領域8,強相関系:高温超伝導,強相関f電子系など)

    田久保 耕, 紫牟田 雅之, 金 廷恩, 加藤 健一, 高田 昌樹, 勝藤 拓郎

    日本物理学会講演概要集 64 (2) 403-403 2009年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  66. 28aTJ-7 Sr_3Ir_2O_7の結晶構造と磁性(フラストレーション系他,領域8,強相関系:高温超伝導,強相関f電子系など)

    大橋 啓, 高山 知弘, 藤山 茂樹, 福永 武男, 橋爪 大輔, 杉本 邦久, 大隈 寛幸, 有馬 孝尚, 高田 昌樹, 高木 英典

    日本物理学会講演概要集 64 (2) 566-566 2009年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  67. 4年目を迎えた AOFSRR (Asia-Oceania Forum for Synchrotron Radiation Research) の活動について

    高田 昌樹

    放射光 22 (2) 49-55 2009年3月31日

    出版者・発行元:日本放射光学会

    ISSN:0914-9287

  68. 28pRE-3 反応現象のX線ピンポイント構造計測II : DVD材料の高速相変化の観測(28pRE 領域10,領域5合同 X線・粒子線(X線),領域10(誘電体,格子欠陥,X線・粒子線,フォノン物性))

    田中 義人, 福山 祥光, 安田 伸広, 金 廷恩, 村山 美乃, 小原 真司, 大沢 仁志, 中川 剛志, 木村 滋, 加藤 健一, 上岡 隼人, 守友 浩, 松永 利之, 児島 理恵, 山田 昇, 鳥海 幸四郎, 大島 隆, 田中 均, 高田 昌樹

    日本物理学会講演概要集 64 (1) 954-954 2009年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  69. 28pRE-2 反応現象のX線ピンポイント構造計測I : 粉末1粒からの結晶構造解析(28pRE 領域10,領域5合同 X線・粒子線(X線),領域10(誘電体,格子欠陥,X線・粒子線,フォノン物性))

    木村 滋, 安田 伸広, 福山 祥光, 金 廷恩, 村山 美乃, 鳥海 幸四郎, 田中 義人, 守友 浩, 黒岩 芳弘, 加藤 健一, 田中 均, 高田 昌樹

    日本物理学会講演概要集 64 (1) 954-954 2009年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  70. 27aTL-5 KMnF_3の高圧下電子密度分布解析(27aTL 遷移金属化合物,領域8(強相関系:高温超伝導,強相関f電子系など))

    青柳 忍, 西堀 英治, 大石 泰生, 黒岩 芳弘, 澤 博, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 64 (1) 528-528 2009年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  71. 28pPSA-40 Co-Feシアノ架橋金属錯体の構造ダイナミクス(28pPSA 領域5ポスターセッション,領域5(光物性))

    中川 剛志, 福山 祥光, 安田 伸広, 大澤 仁志, 金 廷恩, 加藤 健一, 中田 文也, 上岡 隼人, 田中 義人, 木村 滋, 田中 均, 高田 昌樹, 大越 慎一, 守友 浩

    日本物理学会講演概要集 64 (1) 745-745 2009年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  72. 30pYK-2 アモルファスGe_2Sb_2Te_5の構造(30pYK 液体金属,領域6(金属,超低温,超伝導・密度波))

    小原 真司, Akola Jaakko, Jones Robert O., 木村 滋, 小林 啓介, 高田 昌樹, 松永 利之, 児島 理恵, 山田 昇

    日本物理学会講演概要集 64 (1) 803-803 2009年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  73. 30pYK-5 BaTi_2O_5のガラス及び準安定相構造(30pYK 液体金属,領域6(金属,超低温,超伝導・密度波))

    余野 建定, 荒井 康智, 小原 真司, 高田 昌樹, 増野 敦信, 黒岩 芳弘, 伊藤 恵司, 福永 俊晴, 野澤 俊介, 腰原 伸也

    日本物理学会講演概要集 64 (1) 804-804 2009年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  74. 30pYK-3 金属ガラスを形成する2元系Zr合金の液相構造(30pYK 液体金属,領域6(金属,超低温,超伝導・密度波))

    水野 章敏, 秋元 俊彦, 渡邉 匡人, 小原 真司, 高田 昌樹

    日本物理学会講演概要集 64 (1) 803-803 2009年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  75. 28aYG-8 結晶水制御したシアノ錯体の電子密度レベルでの構造変化(28aYG ゼオライト,領域7(分子性固体・有機導体))

    金 廷恩, 加藤 健一, 高田 昌樹, 柴田 恭幸, 守友 浩

    日本物理学会講演概要集 64 (1) 826-826 2009年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  76. 29pYF-1 α-(BEDT-TTF)_2I_3の金属絶縁体転移に伴う電荷移動の直接観測(29pYF α-ET系,輸送現象,領域7(分子性固体・有機導体))

    吉田 芙美子, 加藤 健一, 田中 宏志, 加藤 礼三, 高田 昌樹

    日本物理学会講演概要集 64 (1) 842-842 2009年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  77. 27pPSB-42 配位高分子Zn_2(TcBP)に吸着した酸素分子の整列構造(27pPSB 領域3ポスターセッション,領域3(磁性,磁気共鳴))

    堀 彰宏, 戸田 洋平, 小林 達生, 南方 千晴, 久保田 佳基, 高田 昌樹, 坂本 裕俊, 松田 亮太郎, 樋口 雅一, 北川 進, Schroder M.

    日本物理学会講演概要集 64 (1) 469-469 2009年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  78. 放射光粉末回折データを用いたMEMによる静電ポテンシャル, 電場ベクトルの可視化

    高田 昌樹, 加藤 健一, 吉田 芙美子, 田中 宏志, 守友 浩, 黒岩 芳弘

    日本結晶学会誌 51 (1) 95-96 2009年2月28日

    ISSN:0369-4585

  79. 無容器法から合成されたBaTi<SUB>2</SUB>O<SUB>5</SUB>ガラスの構造

    余野 建定, 野沢 俊介, 腰原 伸也, 荒井 康智, 依田 眞一, 小原 真司, 高田 昌樹, 増野 敦信, 黒岩 芳弘, 伊藤 恵司, 福永 俊晴

    日本セラミックス協会 年会・秋季シンポジウム 講演予稿集 2009 (0) 138-138 2009年

    出版者・発行元:公益社団法人 日本セラミックス協会

    DOI: 10.14853/pcersj.2009S.0.138.0  

    詳細を見る 詳細を閉じる

    無容器法はレーザー加熱と組み合わせることにより高温融体を無容器状態で保持できることから、高純度バルクガラスが広い組成範囲で得られるという利点があり、新規ガラス材料開発の観点からも有用な方法である。本研究ではガスジェット浮遊法を用いて合成したBaTi&lt;SUB&gt;2&lt;/SUB&gt;O&lt;SUB&gt;5&lt;/SUB&gt;バルクガラスの構造を高エネルギーX線回折、中性子回折、逆モンテカルロシミュレーション(RMC)により解析した。その結果、TiO&lt;SUB&gt;5&lt;/SUB&gt;がネットワークを形成し、Baの周りのOの配位数はランダム、すなわち配位数に分布があることが明らかになった。

  80. 23aWF-10 放射光粉末法によるシアノ錯体ナノ空間中の水位置の決定(23aWF ゼオライト・分子性固体,領域7(分子性固体・有機導体))

    金 廷恩, 守友 浩, 中田 文也, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 63 (2) 789-789 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  81. 22aPS-71 Co-Feシアノ架橋金属錯体の構造ダイナミクス(22aPS 領域5ポスターセッション,領域5(光物性))

    中川 剛志, 福山 祥光, 安田 伸広, 大澤 仁志, 金 廷恩, 加藤 健一, 中田 文也, 上岡 隼人, 田中 義人, 木村 滋, 田中 均, 高田 昌樹, 大越 慎一, 守友 浩

    日本物理学会講演概要集 63 (2) 667-667 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  82. 22pYD-7 超安定光源SPring-8が拓くマイクロビーム・時分割構造科学(22pYD 領域5,領域1合同シンポジウム:未踏波長領域における新コヒーレント光源への期待,領域1(原子・分子,量子エレクトロニクス,放射線物理))

    高田 昌樹

    日本物理学会講演概要集 63 (2) 134-134 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  83. 21pPSB-27 多孔性金属錯体Cd(bpndc)(bpy)に吸着した酸素分子の整列構造と磁性(21pPSB 領域3ポスターセッション,領域3(磁性,磁気共鳴))

    久保田 佳基, 南方 千晴, 堀 彰宏, 戸田 洋平, 鈴木 雄太, 小林 達生, 松尾 晶, 金道 浩一, 高田 昌樹, 田中 大輔, 北川 進

    日本物理学会講演概要集 63 (2) 408-408 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  84. 21pPSB-26 多孔性配位高分子CCHDに吸着した酸素分子の構造と磁性II(21pPSB 領域3ポスターセッション,領域3(磁性,磁気共鳴))

    堀 彰宏, 戸田 洋平, 鈴木 雄太, 小林 達生, 久保田 佳基, 松尾 晶, 金道 浩一, 高田 昌樹, 坂本 裕俊, 北川 進

    日本物理学会講演概要集 63 (2) 408-408 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  85. 22pQA-15 カゴメ格子系SrV_xGa_<12-x>O_<19>の軌道自由度とスピンフラストレーション(22pQA V酸化物,領域8(強相関系:高温超伝導,強相関f電子系など))

    宮崎 潤野, 曽根原 岳志, 金 廷恩, 加藤 健一, 高田 昌樹, 勝藤 拓郎

    日本物理学会講演概要集 63 (2) 549-549 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  86. 23aYJ-11 高圧下における液体酸素と液体窒素の配向相関(23aYJ 液体金属,領域6(金属,超低温,超伝導・密度波))

    小原 真司, 大石 泰生, 赤浜 裕一, 川村 春樹, 高田 昌樹, Temleitner L., Pusztai L.

    日本物理学会講演概要集 63 (2) 722-722 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  87. 22aYJ-4 Cs(FH)_<2.3>F液体の構造(22aYJ 液体金属,領域6(金属,超低温,超伝導・密度波))

    小原 真司, 森田 秀利, 松本 一彦, 萩原 理加, 鈴谷 賢太郎, 高田 昌樹, Siewenie J. E., Benmore C. J.

    日本物理学会講演概要集 63 (2) 711-711 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  88. 23pQF-1 Sm_<1-x>Gd_xTiO_3の磁性と格子の相関(23pQF Ti酸化物他,領域8(強相関系:高温超伝導,強相関f電子系など))

    紫牟田 雅之, 鈴木 健士, 金 廷恩, 加藤 健一, 高田 昌樹, 勝藤 拓郎

    日本物理学会講演概要集 63 (2) 581-581 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  89. 21aTC-1 多孔性配位高分子における原子・分子吸着機構の第一原理計算による解析(21aTC MMX・NI転移・π-d系,領域7(分子性固体・有機導体))

    津秋 俊夫, 田中 宏志, 久保田 佳基, 大場 正昭, 北川 進, 高田 昌樹

    日本物理学会講演概要集 63 (2) 743-743 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  90. 22pYD-7 超安定光源SPring-8が拓くマイクロビーム・時分割構造科学(22pYD 領域5,領域1合同シンポジウム:「未踏波長領域における新コヒーレント光源への期待」,領域5(光物性))

    高田 昌樹

    日本物理学会講演概要集 63 (2) 676-676 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  91. 20pYJ-9 Al_2RuとGa_2Ru結晶の電子密度分布と熱電物性(20pYJ 準結晶,領域6(金属,超低温,超伝導・密度波))

    鈴村 彰敏, 高際 良樹, 細井 慎, 木村 薫, 金 廷恩, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 63 (2) 696-696 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  92. 23aQG-8 X線磁気回折のための斜め45度直線偏光制御技術の開発(23aQG 磁気共鳴一般・実験技術開発・磁性一般,領域3(磁性,磁気共鳴))

    酒井 創一朗, 大隅 寛幸, 森田 健士, 米須 尚, 有馬 孝尚, 西野 吉則, 玉作 賢治, 田中 義人, 石川 哲也, 高田 昌樹

    日本物理学会講演概要集 63 (2) 431-431 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  93. 21aQA-10 SPring-8の高輝度X線と大型湾曲IPカメラを用いたDyMnO_3の精密構造解析(21aQA マルチフェロイック2,領域8(強相関系:高温超伝導,強相関f電子系など))

    奥山 大輔, 青柳 忍, 杉本 邦久, 森吉 千佳子, 大隅 寛幸, 施 哲修, 岡林 弘卓, 佐藤 亮太, 橋本 隆, 黒岩 芳弘, 澤 博, 西堀 英治, 高田 昌樹, 田口 康二郎, 有馬 孝尚, 金子 良夫, 十倉 好紀

    日本物理学会講演概要集 63 (2) 483-483 2008年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  94. 光ディスク材料Ge_2Sb_2Te_5の高速相変化モデル

    高田 昌樹

    應用物理 77 (7) 827-830 2008年7月10日

    出版者・発行元:応用物理学会

    ISSN:0369-8009

  95. 23aPS-102 多孔性配位高分子Cu-CHDに吸着した酸素分子の磁性と構造(23aPS ポスターセッション,領域3(磁性,磁気共鳴))

    堀 彰宏, 山口 毅典, 小林 達生, 久保田 佳基, 松尾 晶, 金道 浩一, 高田 昌樹, 北川 進

    日本物理学会講演概要集 63 (1) 449-449 2008年2月29日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  96. 24aWQ-3 パイロクロア型Ru酸化物の金属絶縁体転移に伴う電子密度レベルでの構造変化(24aWQ Ru酸化物,領域8(強相関係:高温超伝導,強相関f電子系など))

    加藤 健一, 高田 昌樹, 山本 文子, 高木 英典

    日本物理学会講演概要集 63 (1) 562-562 2008年2月29日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  97. 23aWL-3 X線磁気回折のための偏光回転技術の開発とLS分離への応用(23aWL 磁性共鳴一般,実験技術開発,磁性一般,領域3(磁性,磁気共鳴))

    大隅 寛幸, 酒井 創一朗, 森田 健士, 米須 尚, 有馬 孝尚, 高田 昌樹, 西野 吉則, 玉作 賢治, 石川 哲也

    日本物理学会講演概要集 63 (1) 423-423 2008年2月29日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  98. Development of a polarization rotator for X-ray magnetic diffraction

    Hiroyuki Ohsumi, Soichiro Sakai, Morita Takeshi, Komesu Takashi, Arima Taka-hisa, Nishino Yoshinori, Tamasaku Kenji, Ishikawa Tetsuya, Takata Masaki

    ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 64 C576-C576 2008年

    出版者・発行元:INT UNION CRYSTALLOGRAPHY

    DOI: 10.1107/S010876730808149X  

    ISSN:2053-2733

  99. X-ray focusing by using compound refractive lens optimized for high-pressure XRD at SPring-8

    Yasuo Ohishi, Hirao Naohisa, Hirose Kei, Takata Masaki

    ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 64 C181-C182 2008年

    出版者・発行元:INT UNION CRYSTALLOGRAPHY

    DOI: 10.1107/S0108767308094208  

    ISSN:2053-2733

  100. First success in direct evaluation of electron density distribution of polymer by X-N method

    Kohji Tashiro, Makoto Ilanesaka, Yosihnori Yoshizawa, Takashi Ohhara, Kazuo Kurihara, Ryota Kuroki, Taro Tamada, Satoru Fujiwara, Tomoji Ozeki, Masaki Takata, Sono Sasaki, Shinji Kohara

    ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 64 C213-C213 2008年

    出版者・発行元:INT UNION CRYSTALLOGRAPHY

    DOI: 10.1107/S010876730809315X  

    ISSN:2053-2733

  101. 21aXK-2 ピンポイント構造計測によるDVD記録材料の時分割構造評価(結晶成長,領域9,表面・界面,結晶成長)

    福山 祥光, 安田 伸広, 金 廷恩, 村山 美乃, 田中 義人, 木村 滋, 守友 浩, 鳥海 幸四郎, 大島 隆, 上岡 隼人, 田中 均, 松永 利之, 児島 理恵, 山田 昇, 加藤 健一, 小原 真司, 高田 昌樹

    日本物理学会講演概要集 62 (2) 908-908 2007年8月21日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  102. 23pTK-5 擬二次元物質η-Mo_4O_<11>のMEMによる静電ポテンシャル分布の可視化(誘電体,領域10,誘電体,格子欠陥,X線・粒子線,フォノン物性)

    酒井 創一朗, 寺戸 良博, 森吉 千佳子, 黒岩 芳弘, 田中 宏志, 根岸 彩子, 高田 昌樹

    日本物理学会講演概要集 62 (2) 1007-1007 2007年8月21日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  103. 23pTK-6 MEM/Rietveld法による強誘電体BaTi_2O_5の相転移研究(誘電体,領域10,誘電体,格子欠陥,X線・粒子線,フォノン物性)

    三好 覚, 沖崎 直也, 森吉 千佳子, 黒岩 芳弘, 余野 建定, 荒井 康智, 増野 敦信, 田中 宏志, 高田 昌樹

    日本物理学会講演概要集 62 (2) 1007-1007 2007年8月21日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  104. 23pPSB-60 時間分解X線回折装置を用いたピンポイント構造計測(領域5ポスターセッション,領域5,光物性)

    福山 祥光, 安田 伸広, 金 廷恩, 村山 美乃, 田中 義人, 木村 滋, 守友 浩, 鳥海 幸四郎, 大島 隆, 上岡 隼人, 田中 均, 松永 利之, 児島 理恵, 山田 昇, 加藤 健一, 小原 真司, 高田 昌樹

    日本物理学会講演概要集 62 (2) 785-785 2007年8月21日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  105. 24aWH-4 スピネル型CoV_2O_4における磁性転移と構造異常(スピネル,電荷・軌道整列,領域8,強相関係:高温超伝導,強相関f電子系など)

    武井 春樹, 勝藤 拓郎, 大坂 恵一, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 62 (2) 651-651 2007年8月21日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  106. 24aRC-8 多孔性配位高分子におけるアセチレン吸着過程の第一原理計算による解析(分子磁性・金属架橋,領域7,分子性固体・有機導体)

    津秋 俊夫, 田中 宏志, 久保田 佳基, 大場 正昭, 北川 進, 高田 昌樹

    日本物理学会講演概要集 62 (2) 899-899 2007年8月21日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  107. 24aRC-7 Co-Wシアノ錯体の温度-圧力相図と構造との相関(分子磁性・金属架橋,領域7,分子性固体・有機導体)

    金 廷恩, 守友 浩, 大石 泰生, 加藤 健一, 高田 昌樹, 大越 慎一

    日本物理学会講演概要集 62 (2) 899-899 2007年8月21日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  108. 22aXP-6 PbO-SiO_2ガラスのネットワーク構造(液体金属,領域6,金属,超低温,超伝導・密度波)

    小原 真司, 大野 英雄, 鈴谷 賢太郎, 高田 昌樹, Pusztai Laszlo

    日本物理学会講演概要集 62 (2) 811-811 2007年8月21日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  109. 24aWB-4 ミクロ孔をもつ配位高分子に吸着した酸素分子の磁性(量子スピン系(クラスター,一般),領域3,磁性,磁気共鳴)

    小林 達生, 堀 彰宏, 山口 毅典, 松尾 晶, 金道 浩一, 久保田 佳基, 高田 昌樹, 北川 進

    日本物理学会講演概要集 62 (2) 501-501 2007年8月21日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  110. 19aRG-4 V/Mg/Liドープβ菱面体晶ボロンの電子密度分布解析(クラスレート,領域7,分子性固体・有機導体)

    細井 慎, 兵藤 宏, 根津 暁充, 曽我 公平, 桐原 和大, 木村 薫, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 62 (1) 822-822 2007年2月28日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  111. 20aZB-7 放射光を利用したCoWシアノ錯体の電荷移動相転移の研究(光誘起相転移,領域5,光物性)

    金 廷恩, 加藤 健一, 高田 昌樹, 大越 慎一, 守友 浩

    日本物理学会講演概要集 62 (1) 743-743 2007年2月28日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  112. 19aZA-2 光誘起相転移を起こすCo-Feシアノ膜の超高速分光(超高速現象・非線形光学,領域5,光物性)

    上岡 隼人, 中田 文也, 守友 浩, 寳角 敏也, 大越 慎一, 福山 祥光, 田中 義人, 高田 昌樹

    日本物理学会講演概要集 62 (1) 706-706 2007年2月28日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  113. 18pXF-1 液体アルミナおよびアルミナ系ガラスの中距離構造(液体金属(アモルファス・溶融塩・その他),領域6,金属,超低温,超伝導・密度波)

    小原 真司, 高田 昌樹, 鈴谷 賢太郎, 水野 章敏, 渡辺 匡人, 坂元 尚紀, 吉村 昌弘, Benmore Christopher J., Weber J.K. Richard

    日本物理学会講演概要集 62 (1) 769-769 2007年2月28日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  114. マイクロポーラス物質の放射光構造科学の研究

    高田 昌樹, 久保田 佳基, 小林 達生

    ゼオライト 24 (3) 80-87 2007年

    出版者・発行元:ゼオライト学会

    ISSN:0918-7774

  115. SPring-8の産業利用(6)放射光粉末回折法による新しいナノサイエンス

    高田 昌樹, 加藤 健一

    機能材料 26 (12) 86-93 2006年12月

    出版者・発行元:シーエムシー出版

    ISSN:0286-4835

  116. 26pZB-10 Geクラスレートにおける内包原子の運動と物性との相関(26pZB クラスレート,領域7(分子性固体・有機導体))

    良知 健, 熊代 良太郎, 大坂 恵一, 加藤 健一, 高田 昌樹, 大石 泰生, 谷垣 勝己

    日本物理学会講演概要集 61 (2) 718-718 2006年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  117. 25aYK-3 コア・シェル型金属ナノ粒子における水素吸蔵のシェル金属依存性(25aYK 格子欠陥・ナノ構造(微粒子・ナノ構造・炭素物質),領域10(誘電体,格子欠陥,X線・粒子線,フォノン物性))

    小林 浩和, 山内 美穂, 北川 宏, 久保田 佳基, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 61 (2) 799-799 2006年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  118. 24pZQ-9 Sr_<0.78>Er_<0.22>CoO_<3-δ>における酸素欠損整列に誘起された軌道整列(24pZQ Co系(基礎物性),領域8(強相関系:高温超伝導,強相関f電子系など))

    石渡 晋太郎, 小林 航, 寺崎 一郎, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 61 (2) 476-476 2006年8月18日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  119. 28pTD-8 多孔性配位高分子の静電ポテンシャルと分子吸着サイト(28pTD 金属架橋鎖,NI転移,領域7(分子性固体・有機導体))

    田中 宏志, 久保田 佳基, 北川 進, 高田 昌樹

    日本物理学会講演概要集 61 (1) 837-837 2006年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  120. 28aRC-11 3族元素の作る特異な形態の共有結合の観察(28aRC クラスレート,領域7(分子性固体・有機導体))

    細井 慎, 金 泓基, 岡田 純平, 木村 薫, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 61 (1) 824-824 2006年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  121. 27pPSB-29 Spin-Peierls物質TiOBrにおける非整合相の役割(27pPSB 領域3ポスターセッション(酸化物磁性,スピングラス・ランダム・アモルファス系,量子スピン系(一次元系,二次元系),量子スピン系(クラスターおよび一般),フラストレーション系,実験技術開発,磁性一般),領域3(磁性,磁気共鳴))

    佐々木 智生, 水牧 仁一郎, 長井 拓郎, 浅香 透, 加藤 健一, 高田 昌樹, 松井 良夫, 市川 広彦, 秋光 純

    日本物理学会講演概要集 61 (1) 457-457 2006年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  122. 最近の展望 放射光粉末回折法による先端材料の精密構造物性の研究

    高田 昌樹, 加藤 健一

    応用物理 74 (9) 1201-1204 2005年9月

    出版者・発行元:応用物理学会

    ISSN:0369-8009

  123. 19aXH-1 新しいスピンパイエルス物質TiOBrの整合・非整合相転移(量子スピン系(一次元),領域3(磁性,磁気共鳴))

    佐々木 智生, 長井 拓郎, 水牧 仁一郎, 浅香 透, 加藤 健一, 高田 昌樹, 松井 良夫, 秋光 純

    日本物理学会講演概要集 60 (2) 279-279 2005年8月19日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  124. 19pXF-7 PdPt金属ナノ粒子の水素吸蔵(微粒子・クラスタ,領域9(表面・界面,結晶成長))

    小林 浩和, 山内 美穂, 北川 宏, 久保田 佳基, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 60 (2) 731-731 2005年8月19日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  125. 21pYK-13 アモルファスGe-Te合金の局所構造(液体金属(カルコゲン系),領域6(金属,超低温,超伝導・密度波))

    臼杵 毅, 亀田 恭男, 櫻井 雅樹, 小原 真司, 高田 昌樹

    日本物理学会講演概要集 60 (2) 660-660 2005年8月19日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  126. 22pXA-5 Vドープβ菱面体晶ボロンの電子密度分布解析(クラスター・ゼオライト,領域7(分子性固体・有機導体))

    細井 慎, 金 泓基, 岡田 純平, 桐原 和大, 曽我 公平, 木村 薫, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 60 (2) 721-721 2005年8月19日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  127. 20aYM-8 X線MEM電荷密度解析によるPbTiO_3の静電ポテンシャル(誘電体,領域10(誘電体,格子欠陥,X線・粒子線,フォノン物性))

    稲澤 猛, 田中 宏志, 黒岩 芳弘, 高田 昌樹

    日本物理学会講演概要集 60 (2) 808-808 2005年8月19日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  128. 26pXL-4 X-ray Charge Density Studies by MEM/Rietveld Method(Advanced diffractometry, microscopy and spectroscopy for structurally complex systems)

    高田 昌樹

    日本物理学会講演概要集 60 (1) 750-750 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  129. 24aYP-12 放射光X線を用いたTiOBrの格子歪みの観測II(量子スピン系(一次元),領域3(磁性,磁気共鳴))

    佐々木 智生, 水牧 仁一朗, 高田 昌樹, 秋光 純

    日本物理学会講演概要集 60 (1) 412-412 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  130. 24pYR-1 ペロブスカイト型誘電体のcubic相の結合状態から相転移を予測することは可能か(誘電体,領域10(誘電体, 格子欠陥, X線・粒子線, フォノン物性))

    黒岩 芳弘, 寺戸 良博, 澤田 昭勝, 青柳 忍, 西堀 英治, 坂田 誠, 高田 昌樹

    日本物理学会講演概要集 60 (1) 896-896 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  131. 27aTA-8 スピネル型FeV_2O_4におけるスピン-軌道同時整列(フラストレーション系(パイロクロア・スピネル),領域8(強相関系:高温超伝導,強相関f電子系など))

    新宮 昌生, 勝藤 拓郎, 加藤 健一, 大坂 恵一, 高田 昌樹

    日本物理学会講演概要集 60 (1) 597-597 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  132. 25pPSA-68 スピネル硫化物CuV_2S_4が示す相転移に伴う構造変化(低温,領域8ポスターセッション,領域8(強相関系:高温超伝導,強相関f電子系など))

    岡田 宏成, 小山 佳一, 加藤 健一, 大坂 恵一, 高田 昌樹, 渡辺 和雄

    日本物理学会講演概要集 60 (1) 577-577 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  133. 24pPSB-26 キラル分子磁性体の低温X線回折実験(量子スピン系,化合物磁性,スピングラス・ランダム系,アモルファス系,フラストレーション系,磁気共鳴一般,磁性一般,領域3(磁性,磁気共鳴))

    大隅 寛幸, 高田 昌樹, 井上 克也, 沼田 陽平, 奥田 一樹, 伊藤 光宏

    日本物理学会講演概要集 60 (1) 444-444 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  134. 25aYM-2 水素圧力下におけるPd/Ptナノ粒子のin-situ XRD測定(格子欠陥・ナノ構造,領域10(誘電体, 格子欠陥, X線・粒子線, フォノン物性))

    小林 浩和, 山内 美穂, 久保田 佳基, 高田 昌樹, 加藤 健一, 北川 宏

    日本物理学会講演概要集 60 (1) 902-902 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  135. 25aYK-12 超伝導体Ba_<24>Ge_<100>におけるBaラットリング現象の直接観察(クラストレート,領域7(分子性固体・有機導体))

    大坂 恵一, 加藤 健一, 高田 昌樹, 小林 賢介, 良知 健, 熊代 良太郎, 谷垣 勝己, 福岡 宏, 山中 昭司

    日本物理学会講演概要集 60 (1) 786-786 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  136. 27pYK-1 多孔性配位高分子に吸着した水素分子の直接観測(金属鎖(MMX, MXなど),領域7(分子性固体・有機導体))

    久保田 佳基, 高田 昌樹, 松田 亮太郎, 北浦 良, 北川 進, 小林 達生, 加藤 健一, 坂田 誠

    日本物理学会講演概要集 60 (1) 822-822 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  137. 24aTA-2 CeCu_2Ge_2の低温における体積の圧力依存性(重い電子超伝導(Ce化合物),領域8(強相関系:高温超伝導,強相関f電子系など))

    武田 圭生, 小林 達生, 日高 宏之, 清水 克哉, 安達 隆文, 大石 泰生, 高田 昌樹, 綿貫 徹, 下村 理, 大貫 惇睦

    日本物理学会講演概要集 60 (1) 484-484 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  138. 24pWF-6 (Pr_<1-y>Sm_y)_<1-x>Ca_xCoO_3のスピン転移機構の考察(Co系1(ペロブスカイト・その他),領域8(強相関系:高温超伝導,強相関f電子系など))

    藤田 利晃, 川端 正平, 佐藤 正俊, 伊奈 弘善, 西堀 英治, 坂田 誠, 安達 隆文, 大石 泰生, 高田 昌樹

    日本物理学会講演概要集 60 (1) 506-506 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  139. 24pWF-8 Pr_<1-x>Ca_xCoO_3の低温高圧下における電子密度レベルの構造変化(Co系1(ペロブスカイト・その他),領域8(強相関系:高温超伝導,強相関f電子系など))

    西堀 英治, 伊奈 弘善, 坂田 誠, 藤田 利晃, 左右田 稔, 佐藤 正俊, 安達 隆文, 大石 泰生, 高田 昌樹

    日本物理学会講演概要集 60 (1) 506-506 2005年3月4日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  140. Direct Observation of Hydrogen Molecules adsorbed in a Coordination Polymer

    Yoshiki Kubota, Masaki Takata, Ryotaro Matsuda, Ryo Kitaura, Susumu Kitagawa, Tatsuo C. Kobayashi, Kenichi Kato, Makoto Sakata

    ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 61 C403-C403 2005年

    出版者・発行元:INT UNION CRYSTALLOGRAPHY

    DOI: 10.1107/S0108767305082917  

    ISSN:2053-2733

  141. 非共鳴X線磁気散乱における新規偏光解析手法 : 可変散乱面法

    大隅 寛幸, 高田 昌樹

    放射光 17 (6) 338-343 2004年11月30日

    出版者・発行元:日本放射光学会

    ISSN:0914-9287

  142. 13pWH-7 C_<60>FET に於ける界面修飾の及ぼす影響とその評価(FET, 領域 7)

    廣芝 伸哉, 谷垣 勝己, 熊代 良太郎, 赤阪 健, 木村 滋, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 59 (2) 760-760 2004年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  143. 12aYB-6 MEM/Rietveld 法によるα菱面体晶ボロンおよび派生結晶の結合評価(低対称系・格子欠陥, 領域 4)

    細井 慎, 金 泓基, 木村 薫, 永田 智啓, 桐原 和大, 曽我 公平, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 59 (2) 582-582 2004年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  144. 13pWH-7 C_<60>FET に於ける界面修飾の及ぼす影響とその評価(FET, 領域 8)

    廣芝 伸哉, 谷垣 勝己, 熊代 良太郎, 赤阪 健, 木村 滋, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 59 (2) 506-506 2004年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  145. 14pWG-3 放射光 X 線を用いた T_iOBr の格子歪みの観測(量子スピン系 : 一次元及び二次元, 領域 3)

    佐々木 智生, 水牧 仁一朗, 加藤 健一, 渡部 康夫, 西端 慶樹, 高田 昌樹, 秋光 純

    日本物理学会講演概要集 59 (2) 405-405 2004年8月25日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  146. 28pXC-12 Pr_<1-x>Ca_xCoO_3の局所構造と電子状態(Co系酸化物)(領域8)

    藤田 利晃, 宮下 健, 安井 幸夫, 小林 義明, 佐藤 正俊, 下条 豊, 井川 直樹, 石井 慶信, 加倉井 和久, 西堀 英治, 坂田 誠, 安達 隆文, 大石 泰生, 高田 昌樹

    日本物理学会講演概要集 59 (1) 591-591 2004年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  147. 28pPSA-3 CeB_6の磁気モーメントはどこにあるのか?(III)(領域8(磁性)ポスターセッション(希土類・アクチナイド化合物))(領域8)

    高阪 勇輔, 市川 広彦, 戸賀崎 真貴子, 齋藤 雅洋, 岡田 典子, 西堀 英治, 廣田 和馬, 西 正和, 加倉井 和久, 野田 幸男, 国井 暁, 高田 昌樹, 坂田 誠, 秋光 純

    日本物理学会講演概要集 59 (1) 602-602 2004年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  148. 28pWN-10 MEM/Rietveld法によるα菱面体晶ボロンおよびその派生結晶の電子密度解析(グラファイト・クラスター・クラスレート)(領域7)

    細井 慎, 金 泓基, 永田 智啓, 桐原 和大, 曽我 公平, 木村 薫, 加藤 健一, 高田 昌樹

    日本物理学会講演概要集 59 (1) 856-856 2004年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  149. 28aXF-6 スピンクロスオーバー錯体における光誘起による電子密度レベルでの構造変化(光誘起相転移)(領域5)

    加藤 健一, 守友 浩, 高田 昌樹, 坂田 誠, 仲本 亜希雄, 小島 憲道

    日本物理学会講演概要集 59 (1) 729-729 2004年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  150. 28aPS-99 NbB_<2+x>における結晶構造と超伝導特性(領域8 ポスターセッション)(領域8)

    高際 寛之, 岡田 典子, 西堀 英治, 高田 昌樹, 坂田 誠, 秋光 純

    日本物理学会講演概要集 59 (1) 578-578 2004年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  151. 28aPS-95 Na_xCoO_2・yH_2Oの超伝導II(領域8 ポスターセッション)(領域8)

    桜井 裕也, 高田 和典, 福田 勝利, 長田 実, 中井 泉, 泉 富士夫, Dilanian Ruben A, 加藤 健一, 高田 昌樹, 佐々木 高義, 室町 英治

    日本物理学会講演概要集 59 (1) 577-577 2004年3月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  152. マキシマムエントロピー法による電子密度分布

    坂田 誠, 西堀 英治, 高田 昌樹

    熱測定 : netsu = Calorimetry and thermal analysis 31 (1) 29-36 2004年1月25日

    出版者・発行元:日本熱測定学会

    ISSN:0386-2615

  153. 27aXB-3 BiMO_3(M=Cr,Mn,Fe,Co,Ni)の構造と物性II(その他の遷移金属化合物)(領域8)

    新高誠司, 東 正樹, 高野 幹夫, 西堀 英治, 高田 昌樹, 坂田 誠, Yamada Ikuya

    日本物理学会講演概要集 59 (1) 511-511 2004年

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  154. マキシマムエントロピー法を用いた物質の精密構造解析

    高田 昌樹, 坂田 誠

    應用物理 72 (9) 1171-1175 2003年9月10日

    出版者・発行元:応用物理学会

    ISSN:0369-8009

  155. 20pTJ-7 集積型銅錯体細孔中の酸素ラダーの構造

    高田 昌樹, 北川 進

    日本物理学会講演概要集 58 (2) 728-728 2003年8月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  156. 20aXE-10 電子密度分布から見る (EDO-TTF)_2PF_6 の金属-絶縁体転移

    青柳 忍, 太田 明, 加藤 健一, 高田 昌樹, 矢持 秀起, 斎藤 軍治

    日本物理学会講演概要集 58 (2) 721-721 2003年8月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  157. 22pTP-8 LiV_2O_4 の圧力誘起電荷整列 II

    武田 圭生, 日高 宏之, 小林 達生, 清水 克哉, 三好 清貴, 藤原 賢二, 竹内 潤, 西堀 英治, 高田 昌樹, 坂田 誠, 安達 隆文, 大石 泰生, 綿貫 徹, 下村 理

    日本物理学会講演概要集 58 (2) 543-543 2003年8月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  158. 22pXG-5 フラーレン薄膜 FET における薄膜構造と物性

    熊代 良太郎, 大橋 弘孝, 杉原 周二, 廣芝 伸哉, 谷垣 勝己, Nikos Tagmatarchis, 加藤 治人, 篠原 久典, 赤坂 健, 加藤 健一, 青柳 忍, 木村 滋, 高田 昌樹

    日本物理学会講演概要集 58 (2) 753-753 2003年8月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  159. 21pWA-2 CoS_2 における構造と磁性との相関 : 圧力効果

    町田 晃彦, 綿貫 徹, 池田 智宏, 守友 浩, 加藤 健一, 高田 昌樹, 下村 理

    日本物理学会講演概要集 58 (2) 380-380 2003年8月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  160. 20pTN-17 RbMn[Fe(CN)_6] のヤーンテラー歪みに伴う電子密度レベルでの構造変化

    加藤 健一, 守友 浩, 高田 昌樹, 坂田 誠, 浜田 典昭, 所 裕子, 大越 慎一, 橋本 和仁

    日本物理学会講演概要集 58 (2) 448-448 2003年8月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  161. 22aPS-58 Y_<1-x>Ca_xTiO_3 (x&acd;0.4) の相分離誘起金属-絶縁体転移に対する Ca 置換効果と圧力効果

    坪田 雅己, 中野 寿寛, 内平 和幸, 倉 宗一郎, 竹村 征樹, 梅尾 和則, 伊賀 文俊, 高畠 敏郎, 西堀 英治, 高田 昌樹, 坂田 誠, 加藤 健一, 大石 泰生

    日本物理学会講演概要集 58 (2) 525-525 2003年8月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  162. 21aXB-3 非共鳴 X 線磁気散乱における偏光解析の新手法

    大隅 寛幸, 水牧 仁一朗, 木村 滋, 高田 昌樹, 壽榮松 宏仁

    日本物理学会講演概要集 58 (2) 850-850 2003年8月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  163. 21aXB-1 MEM 電子密度解析における系統的誤差の考察

    清水 有子, 田中 宏志, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 58 (2) 849-849 2003年8月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  164. 28pYD-9 種々の FET 基板上におけるフラーレンおよび関連物質の構造

    谷垣 勝己, 大橋 弘孝, 熊代 良太郎, 加藤 健一, 青柳 忍, 木村 滋, 高田 昌樹

    日本物理学会講演概要集 58 (1) 787-787 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  165. 28pYE-6 RbMn[Fe(CN)_6] の圧力誘起効果

    栗城 彰, 守友 浩, 大石 康生, 加藤 健一, 所 裕子, 大越 慎一, 橋本 和仁, 西堀 英治, 高田 昌樹, 坂田 誠, 中村 新男

    日本物理学会講演概要集 58 (1) 689-689 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  166. 28pYE-5 スピンクロスオーバー錯体 [Fe(ptz)_6] (BF_4)_2 における結合電子レベルでの構造解析

    加藤 健一, 守友 浩, 高田 昌樹, 坂田 誠, 仲本 亜希雄, 小島 憲道

    日本物理学会講演概要集 58 (1) 689-689 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  167. 30pXJ-8 KNbO_3 および KTaO_3 のイオン状態

    木村 明弘, 黒岩 芳弘, 澤田 昭勝, 青柳 忍, 田中 宏志, 西堀 英治, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 58 (1) 918-918 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  168. 30pXJ-5 反強誘電体 PbZrO_3 の精密電子密度分布解析

    青柳 忍, 黒岩 芳弘, 澤田 昭勝, 田中 宏志, 西堀 英治, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 58 (1) 918-918 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  169. 28aYE-9 プルシアン・ブルー型錯体の光励起相における構造物性

    花輪 雅史, 守友 浩, 栗城 彰, 立石 純一郎, 加藤 健一, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 58 (1) 678-678 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  170. 28aZB-1 酸素分子ラダー I : ボトムアップ構築のための集積型細孔銅錯体の合成と酸素吸着

    北川 進, 松田 亮太郎, 北浦 良, 張 浩徹, 小林 達生, 高田 昌樹

    日本物理学会講演概要集 58 (1) 782-782 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  171. 28aZB-2 酸素分子ラダー II : 電子密度解析による吸着分子の直接観察

    久保田 佳基, 高田 昌樹, 北浦 良, 松田 亮太郎, 北川 進, 張 浩徹, 小林 達生, 坂田 誠

    日本物理学会講演概要集 58 (1) 782-782 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  172. 29pZB-7 RE_3C_<70> における結合状態と構造相転移

    伊藤 崇芳, 竹延 大志, 岩佐 義宏, 三谷 忠興, 高田 昌樹, 西堀 英治, 坂田 誠

    日本物理学会講演概要集 58 (1) 804-804 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  173. 29pPSB-22 Ce 系圧力誘起超伝導体の低温高圧下粉末 X 線回折

    武田 圭生, 安達 隆文, 小林 達生, 清水 克哉, 日高 宏之, 鷹尾 大五郎, 西堀 英治, 高田 昌樹, 坂田 誠, 大石 泰生, 綿貫 徹, 下村 理, 大貫 惇睦

    日本物理学会講演概要集 58 (1) 565-565 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  174. 28aPS-51 RNiO_3(R=Pr, Nd) の金属絶縁体転移における電荷不均化

    齊藤 高志, 東 正樹, 西堀 英治, 高田 昌樹, 坂田 誠, 中山 則昭, 有馬 孝尚, 木村 剛, 浦野 千春, 高野 幹夫

    日本物理学会講演概要集 58 (1) 504-504 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  175. 29pPSA-14 CeB_6 の磁気モーメントはどこにあるのか? (II)

    齋藤 雅洋, 岡田 典子, 西堀 英治, 高際 寛之, 横尾 哲也, 中島 健次, 西 正和, 加倉井 和久, 野田 幸男, 国井 暁, 高田 昌樹, 坂田 誠, 秋光 純

    日本物理学会講演概要集 58 (1) 555-555 2003年3月6日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  176. 新しい実験手法が拓く構造物性 MEM/Rietveld法によって見る電子密度分布 (放射光X線による構造物性研究の最前線 特集号) -- (放射光構造物性研究の最前線)

    高田 昌樹, 西堀 英治, 加藤 健一

    固体物理 37 (9) 663-672 2002年9月

    出版者・発行元:アグネ技術センタ-

    ISSN:0454-4544

  177. 6aPS-122 ペロブスカイト型酸化物BiMO3(M=Cr,Co)の高圧合成と物性(4f・5f電子系,重い電子系,遷移金属酸化物,領域8)

    新高 誠司, 東 正樹, 石渡 晋太郎, 高野 幹夫, 西堀 英治, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 57 (2) 455-455 2002年8月13日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  178. 9aXD-6 PrNiO3の低温絶縁体相におけるmonoclinic歪み(Ti,Ni系他,領域8)

    齊藤 高志, 東 正樹, 高野 幹夫, 西堀 英治, 高田 昌樹, 坂田 誠, 中山 則昭, 木村 剛, 浦野 千春

    日本物理学会講演概要集 57 (2) 540-540 2002年8月13日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  179. 9aSL-8 MEMによる価電子密度解析((X線)X線・粒子線,領域10)

    田中 宏志, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 57 (2) 836-836 2002年8月13日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  180. 24pXE-12 MEM/Rietveld法によるAlReSi立方晶近似結晶の電子密度分布(24pXE 準結晶(構造・物性),領域6(金属,超低温,超伝導・密度波分野))

    桐原 和大, 永田 智啓, 木村 薫, 西堀 英治, 加藤 健一, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 57 (1) 727-727 2002年3月1日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  181. 並列処理MEM構造解析プログラム:ENIGMA

    田中 宏志, 高田 昌樹, 西堀 英治, 坂田 誠, 加藤 健一

    日本結晶学会誌日本結晶学会誌 44 (5) 318-320 2002年

    出版者・発行元:The Crystallographic Society of Japan

    DOI: 10.5940/jcrsj.44.318  

    ISSN:0369-4585 1884-5576

  182. 18pWF-8 放射光を用いた新奇フラーレン, ネットワーク固体の精密構造物性研究

    高田 昌樹, 西堀 英治, 坂田 誠

    日本物理学会講演概要集 56 (2) 692-692 2001年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  183. 19aTH-1 「並列処理 MEM 構造解析プログラム(Enigma)の開発」

    飯石 崇, 田中 宏志, 高田 昌樹, 西堀 英治, 加藤 建一, 坂田 誠

    日本物理学会講演概要集 56 (2) 809-809 2001年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  184. 17aTJ-7 希土類金属ドープフラーレンの構造相転移

    Chi Dam Hieu, 植原 克行, 伊藤 崇芳, Takenobu T., 岩佐 義宏, 三谷 忠興, 高田 昌樹, 西堀 英治, 坂田 誠

    日本物理学会講演概要集 56 (2) 674-674 2001年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  185. 17pTJ-4 フラーレン内包チューブのXRD

    阿部 真利, 真庭 豊, 藤原 竜児, 吉良 弘, 藤 秀樹, 片浦 弘道, 鈴木 信三, 阿知波 洋次, 藤原 明比古, 西堀 英治, 高田 昌樹, 坂田 誠, 壽榮松 宏仁

    日本物理学会講演概要集 56 (2) 678-678 2001年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  186. 18pTE-1 スピネル型AlV_<2-x>Cr_xO_4の電荷整列融解とスピンフラストレーション

    松野 謙一郎, 勝藤 拓郎, 野原 実, 町田 晃彦, 守友 浩, 加藤 健一, 西堀 英治, 高田 昌樹, 坂田 誠, 高木 英典

    日本物理学会講演概要集 56 (2) 415-415 2001年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  187. 18pTE-10 TbBaCo_2O_<5.5>の金属絶縁体転移温度における構造変化

    楠屋 宏行, 町田 晃彦, 守友 浩, 中村 新男, 加藤 健一, 西堀 英治, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 56 (2) 418-418 2001年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  188. 17pPSB-10 強磁性YTiO_3の白色X線磁気回折

    伊藤 正久, 安達 弘通, 中尾 裕則, 村上 洋一, 加藤 健一, 西堀 英治, 高田 昌樹, 坂田 誠, 宮川 勇人, 七尾 進, 上村 重明, 圓山 裕, 田口 康二郎, 十倉 好紀, 荒川 悦雄, 並河 一道

    日本物理学会講演概要集 56 (2) 341-341 2001年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  189. 20aTE-9 六方晶RMnO_3の強誘電転移と置換効果

    勝藤 拓郎, 正木 元基, 町田 晃彦, 守友 浩, 加藤 健一, 西堀 英治, 高田 昌樹, 坂田 誠, 森 茂生, 北澤 宏一, 高木 英典

    日本物理学会講演概要集 56 (2) 500-500 2001年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  190. 19pYB-3 金属絶縁体転移系Y_<0.61>Ca_<0.39>TiO_3における構造相転移及び相分離

    加藤 健一, 西堀 英治, 高田 昌樹, 坂田 誠, 中野 寿寛, 内平 和幸, 坪田 雅己, 伊賀 文俊, 高畠 敏郎

    日本物理学会講演概要集 56 (2) 491-491 2001年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  191. 17aYA-9 (Nd,Sm)_<1/2>Sr_<1/2>MnO_3の圧力効果

    栗城 彰, 守友 浩, 町田 晃彦, 中村 新男, 西堀 英治, 高田 昌樹, 坂田 誠, 大石 泰生, 下村 理

    日本物理学会講演概要集 56 (2) 378-378 2001年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  192. 19aPS-8 CeB_6の磁気モーメントはどこにあるのか?

    齋藤 雅洋, 高際 寛之, 秋光 純, 西 正和, 加倉井 和久, 高田 昌樹, 岡田 典子, 坂田 誠, 国井 暁

    日本物理学会講演概要集 56 (2) 470-470 2001年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  193. 27aYM-11 マンガン酸化物における電荷分離現象

    町田 晃彦, 守友 浩, 森 茂生, 山本 直紀, 大山 研司, 西堀 英治, 高田 昌樹, 坂田 誠, 中村 新男

    日本物理学会講演概要集 56 (1) 454-454 2001年3月9日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  194. 28pPSB-27 金属-非金属転移系Y_<0.61>Ca_<0,39>TiO_3の異方的伝導と圧力効果

    内平 和幸, 中野 寿寛, 伊賀 文俊, 梅尾 和則, 板東 能生, 高畠 敏郎, 高田 昌樹, 西堀 英治, 坂田 誠, 山片 正明

    日本物理学会講演概要集 56 (1) 539-539 2001年3月9日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  195. 28aYK-8 CeB_6の軌道整列の直接観測

    齋藤 雅洋, 高際 寛之, 市川 広彦, 横尾 哲也, 秋光 純, 西 正和, 加倉井 和久, 高田 昌樹, 岡田 典子, 坂田 誠, 国井 暁

    日本物理学会講演概要集 56 (1) 482-482 2001年3月9日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  196. 28pYM-7 Sr_2 (Fe_<l-z>Mn_z)MoO_6の結晶合成と磁気相図

    楠屋 宏行, 徐 勝, 町田 晃彦, 守友 浩, 中村 新男, 西堀 英治, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 56 (1) 514-514 2001年3月9日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  197. 27aWB-2 多層カーボンナノチューブの構造 II

    藤原 竜児, 吉 良弘, 藤 秀樹, 真庭 豊, 趙 新洛, 飯島 澄男, 安藤 義則, 藤原 明比古, 西堀 英治, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 56 (1) 730-730 2001年3月9日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  198. 28pYR-3 PbTiO_3常誘電相の精密電子密度分布解析

    青柳 忍, 黒岩 芳弘, 澤田 昭勝, 西堀 英治, 高田 昌樹, 坂田 誠, 原田 仁平

    日本物理学会講演概要集 56 (1) 866-866 2001年3月9日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  199. 28aTC-6 精密電子密度分布からみたη-Mo_4O_<11>の電子状態

    黒岩 芳弘, 赤嶺 博康, 青柳 忍, 澤田 昭勝, 根岸 寛, 根岸 彩子, 佐々木 実, 西堀 英治, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 56 (1) 611-611 2001年3月9日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  200. 30aYJ-8 電荷整列系スピネル型AlV_2O_4の結晶構造とCrドープ依存性

    松野 謙一郎, 勝藤 拓郎, 守友 浩, 町田 晃彦, 西堀 英治, 高田 昌樹, 坂田 誠, 森 茂生, 山本 直紀, 高木 英典

    日本物理学会講演概要集 56 (1) 563-563 2001年3月9日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  201. 30aXD-4 Sm_3C_<70>の構造相転移

    Chi Dam H., 伊藤 崇芳, 竹延 大志, 岩佐 義宏, 三谷 忠興, 西堀 栄治, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 56 (1) 771-771 2001年3月9日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  202. 23pTF-7 第一原理計算によるKCl及びNaClの圧力誘起構造相転移の解析

    池田 智宏, 高田 昌樹, 坂田 誠, 田中 宏志

    日本物理学会講演概要集 55 (2) 667-667 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  203. 22aYF-10 MEM/Rietveld法によるBa_3C_<70>の構造

    高田 昌樹, 西堀 英治, 中村 和義, 坂田 誠, 門脇 伸介, 田中 宏志, 竹延 大志, 伊藤 崇芳, Chi Dam Hieu, 岩佐 義宏, 三谷 洋興

    日本物理学会講演概要集 55 (2) 693-693 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  204. 22aYF-11 Sm_3C_<70>におけるフラーレンダイマー構造と圧力誘起相転移

    Chi Dam Hieu, Chen X. H., 伊藤 崇芳, 竹延 大志, 岩佐 義宏, 三谷 忠興, 高田 昌樹, 西堀 英治, 坂田 誠

    日本物理学会講演概要集 55 (2) 694-694 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  205. 23pTF-12 アルカリ金属のs-d転移に関する電子密度分布解析

    大石 泰生, 高田 昌樹, 西堀 英治, 坂田 誠, 下村 理

    日本物理学会講演概要集 55 (2) 668-668 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  206. 22pSF-13 La_<1.04>Sr_<1.96>Mn_2O_7の圧力誘起金属絶縁体転移に伴う電子密度レベルでの構造変化

    加藤 健一, 西堀 英治, 高田 昌樹, 坂田 誠, 守友 浩, 大石 泰生, 下村 理

    日本物理学会講演概要集 55 (2) 446-446 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  207. 22aPS-19 X線磁気回折によるDyの磁気形状因子測定

    伊藤 正久, 安達 弘通, 山内 邦彦, 西堀 英治, 加藤 健一, 中田 存, 高田 昌樹, 坂田 誠, 宮川 勇人, 渡辺 康裕, 七尾 進, 桜井 浩, 伊藤 文武, 上村 重明, 北本 直也, 圓山 裕, 岸本 俊二, 河田 洋

    日本物理学会講演概要集 55 (2) 334-334 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  208. 22pSF-4 二重ペロブスカイトSr_2FeMoO_6の電子ドープ効果

    守友 浩, 徐 勝, 町田 晃彦, 穐本 卓巳, 西堀 英治, 高田 昌樹, 坂田 誠, 浜田 典昭, 大山 健司

    日本物理学会講演概要集 55 (2) 444-444 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  209. 24pSD-10 Y_<1-x>Ca_xTiO_3の金属-非金属転移温度近傍における格子異常

    中野 寿寛, 伊賀 文俊, 高畠 敏郎, 高田 昌樹, 西堀 英治, 坂田 誠, 松畑 洋文, 久保田 佳基, 山片 正明

    日本物理学会講演概要集 55 (2) 522-522 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  210. 22aSF-5 マンガン酸化物の相分離と絶縁体-金属転移

    町田 晃彦, 守友 浩, 西堀 英治, 高田 昌樹, 坂田 誠, 大山 研司, 森 茂生, 山本 直紀, 中村 新男

    日本物理学会講演概要集 55 (2) 433-433 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  211. 22aPS-55 SrV_6O_<11>の低温構造

    池田 直, 水牧 仁一朗, 畑 慶明, 喜多 英治, 西堀 英治, 高田 昌樹, 菅家 康, 池田 卓史

    日本物理学会講演概要集 55 (2) 343-343 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  212. 23aYH-6 モデルフリーなMEM解析によるフラーレン化合物の構造決定

    坂田 誠, 高田 昌樹, 西堀 英治

    日本物理学会講演概要集 55 (2) 828-828 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  213. 23aYH-7 高圧下におけるKCl,NaClの電子密度レベルでの精密結晶構造解析

    西堀 英治, 洲崎 昌宏, 高田 昌樹, 坂田 誠, 大石 泰生, 下村 理

    日本物理学会講演概要集 55 (2) 828-828 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  214. 23pYQ-6 PbTiO_3の精密電子密度分布解析

    青柳 忍, 赤嶺 博康, 黒岩 芳弘, 澤田 昭勝, 西堀 英治, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 55 (2) 844-844 2000年9月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  215. MEM/Rietveld法による金属フラーレンの構造研究

    高田 昌樹, 西堀 英治, 坂田 誠

    放射光 13 (3) 230-238 2000年6月30日

    出版者・発行元:日本放射光学会

    ISSN:0914-9287

  216. 正20面体クラスター固体α菱面体晶ボロンの奇妙な結合

    藤森 正成, 木村 薫, 高田 昌樹

    固体物理 35 (4) 277-282 2000年4月

    出版者・発行元:アグネ技術センタ-

    ISSN:0454-4544

  217. 24aZL-1 Density Modification Methodによる無機物質構造決定の試み

    須田 伸幸, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 55 (1) 848-848 2000年3月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  218. 24aZL-7 電池材料LiMn_2O_4の高温劣化を伴う結晶組織変化

    木舩 弘一, 浦野 直子, 神戸 哲也, 西堀 英治, 高田 昌樹, 井上 尊夫, 山根 久幸, 佐野 充, 坂田 誠

    日本物理学会講演概要集 55 (1) 849-849 2000年3月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  219. 24aS-11 多層カーボンナノチューブの磁性

    真庭 豊, 藤原 竜児, 吉良 弘, 藤 秀樹, 西堀 英治, 高田 昌樹, 坂田 誠, 趙 新洛, 飯島 澄男, 安藤 義則

    日本物理学会講演概要集 55 (1) 728-728 2000年3月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  220. 25aS-12 SM_3C_<70>におけるフラーレン分子の配向

    Chi Dam Hieu, Che X. H., 竹延 大志, 岩佐 義宏, 三谷 忠興, 高田 昌樹, 西堀 英治, 坂田 誠

    日本物理学会講演概要集 55 (1) 742-742 2000年3月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  221. 25aL-3 低次元層状物質Mo_nO_<3n-1>の放射光を用いた構造研究

    赤嶺 博康, 青柳 忍, 黒岩 芳弘, 澤田 昭勝, 根岸 寛, 根岸 彩子, 佐々木 実, 西堀 英治, 高田 昌樹, 坂田 誠, 笠谷 祐史, 菖蒲 敬久

    日本物理学会講演概要集 55 (1) 602-602 2000年3月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  222. 23pZL-4 SPring-8 BL02B2精密構造物性用大型デパイシェラーカメラの性能評価

    高田 昌樹, 西堀 英治, 久保田 佳基, 杉浦 文俊, 州崎 昌宏, 中村 和義, 加藤 建一, 中田 存, 広瀬 孝二, 黒岩 芳弘, 守友 浩, 山片 正明, 池田 直司, 坂田 誠

    日本物理学会講演概要集 55 (1) 837-837 2000年3月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  223. 24aPS-27 La-Sr-CU-O系酸化物超伝導体の圧力下での構造解析II

    白沢 光, 山田 裕, 高田 昌樹, 松本 征人, 西堀 英治, 安達 隆文, 坂田 誠, 下村 理, 久保 衆伍

    日本物理学会講演概要集 54 (2) 456-456 1999年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  224. 24pJ-10 Nd_<0.5>Sr_<0.5>MnO_3の電荷整列相における電子密度分布

    加藤 健一, 西堀 英治, 高田 昌樹, 坂田 誠, 守友 浩

    日本物理学会講演概要集 54 (2) 477-477 1999年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  225. 27pYM-1 マキシマムエントロピー法により求めたLaves相金属間化合物MgNi_2の電子密度分布

    久保田 佳基, 高田 昌樹, 坂田 誠, 大庭 卓也, 木船 弘一, 唯木 次男

    日本物理学会講演概要集 54 (2) 722-722 1999年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  226. 27aF-5 遷移金属を含むSiおよびGeクラスレートの構造と物性

    川口 哲司, 谷垣 勝己, 高田 昌樹, 西堀 英治, 坂田 誠, 山中 昭司

    日本物理学会講演概要集 54 (2) 771-771 1999年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  227. 25pYJ-10 マキシマムエントロピー法による正方晶BaTiO_3の電子密度分布

    原田 仁平, 坂田 誠, 秋重 幸邦, 油上 恵子, 中田 存, 高田 昌樹

    日本物理学会講演概要集 54 (2) 891-891 1999年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  228. 24aF-4 3金属原子内包フラーレンSc_3@C_<82>の構造

    西堀 英治, 高田 昌樹, 坂田 誠, 稲熊 正康, 篠原 久典

    日本物理学会講演概要集 54 (2) 729-729 1999年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  229. 25aC-7 GaAs金属相のMEM法による電子密度解析

    石松 直樹, 下村 理, 大石 泰生, 高田 昌樹, 西堀 英治, 坂田 誠

    日本物理学会講演概要集 54 (2) 599-599 1999年9月3日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  230. Electron and Nuclear Densities of a Pyrochlore,Y2Sn2O7 Studied by the Maximum Entropy Method (Proceedings of the Second International Conference on SRMS(Synchrotron Radiation in Materials Science)(2))

    Ikeda Tomohiro, Sakata Makoto, Takata Masaki

    Japanese Journal of Applied Physics Pt. 1 Regular Papers, Short Notes & Review Papers 38 (1) 93-96 1999年6月

    出版者・発行元:Publication Office, Japanese Journal of Applied Physics, Faculty of Science, University of Tokyo

    ISSN:0021-4922

  231. A Synchrotron Powder Diffraction Study of Na-LTA (Proceedings of the Second International Conference on SRMS(Synchrotron Radiation in Materials Science)(2))

    Hasegawa Kazuhide, Nishibori Eiji, Takata Masaki

    Japanese Journal of Applied Physics Pt. 1 Regular Papers, Short Notes & Review Papers 38 (1) 65-68 1999年6月

    出版者・発行元:Publication Office, Japanese Journal of Applied Physics, Faculty of Science, University of Tokyo

    ISSN:0021-4922

  232. 28p-C-2 MEMによるNdSr_2Mn_2O_7の軌道整列の直接観察

    加藤 健一, 西堀 英治, 高田 昌樹, 坂田 誠, 守 友浩

    日本物理学会講演概要集 54 (1) 543-543 1999年3月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  233. 29a-XJ-10 MEMによるαボロンの電子密度分布

    中田 存, 高田 昌樹, 藤森 正成, 中山 高博, 木村 薫, 西堀 英治, 坂田 誠

    日本物理学会講演概要集 54 (1) 357-357 1999年3月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  234. 31a-L-2 (La_<1-x>Sr_x)_2CuO_4酸化物超伝導体の加圧下での精密構造解析

    白沢 光, 山田 裕, 松本 征人, 高田 昌樹, 西堀 英治, 坂田 誠, 安達 隆文, 下村 理

    日本物理学会講演概要集 54 (1) 621-621 1999年3月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  235. 28p-PSA-51 TI-2212酸化物高温超伝導体の加圧下での精密構造

    松本 征人, 三宅 正晃, 山田 裕, 長谷川 正, 高田 昌樹, 西堀 英治, 坂田 誠, 大石 泰生, 下村 理

    日本物理学会講演概要集 54 (1) 567-567 1999年3月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  236. 28a-G-3 MEM及びリートベルト法によるAl系正20面体相近似結晶の構造と電子密度分布II

    桐原 和大, 久保田 佳基, 高田 昌樹, 西堀 英治, 木村 薫, 坂田 誠

    日本物理学会講演概要集 54 (1) 502-502 1999年3月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  237. 28p-ZF-6 MEMとリートベルト法によるβ菱面体晶ボロンの電子密度分布の解析

    中山 高博, 藤森 正成, 木村 薫, 中田 存, 高田 昌樹, 西堀 英治, 町田 尚樹, 坂田 誠

    日本物理学会講演概要集 54 (1) 142-142 1999年3月15日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  238. 27p-K-10 MEMによるADP(NH_4H_2PO_4)の精密構造解析

    山村 滋典, 熊沢 紳太郎, 西堀 英治, 高田 昌樹, 坂田 誠, 菅原 洋子

    日本物理学会講演概要集 53 (2) 430-430 1998年9月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  239. 28a-M-7 La@C_<82>の電子密度分布

    西堀 英治, 高田 昌樹, 坂田 誠, 長谷川 正樹, 篠原 久典

    日本物理学会講演概要集 53 (2) 319-319 1998年9月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  240. 25a-YE-7 MEMとリートベルト法によるα菱面体晶ボロンの電子密度分布の解析

    藤森 正成, 木村 薫, 中山 高博, 中田 存, 高田 昌樹, 西堀 英治, 町田 尚樹, 坂田 誠

    日本物理学会講演概要集 53 (2) 152-152 1998年9月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  241. 26a-PS-3 La-Sr-Cu-O系酸化物超伝導体の圧力下での構造解析

    白沢 光, 山田 裕, 高田 昌樹, 松本 征人, 西堀 英治, 安達 隆文, 坂田 誠, 下村 理, 久保 衆伍

    日本物理学会講演概要集 53 (2) 647-647 1998年9月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  242. 27a-J-8 MEMによる金属間化合物MgZn_2およびMgCu_2の電子密度分布

    久保田 佳基, 高田 昌樹, 坂田 誠, 大庭 卓也, 木舩 弘一, 唯木 次男

    日本物理学会講演概要集 53 (2) 605-605 1998年9月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  243. 25p-Q-10 MEM及びリートベルト法によるAl系正20面体相近似結晶の構造と電子密度分布

    桐原 和大, 久保田 佳基, 高田 昌樹, 西堀 英司, 木村 薫, 坂田 誠

    日本物理学会講演概要集 53 (2) 596-596 1998年9月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  244. 26a-YC-6 PrBa_2Cu_4O_8酸化物の加圧下での物性と精密構造解析

    松本 征人, 山田 裕, 高田 昌樹, 堀井 滋, 松下 明行, 安達 隆文, 池田 智宏, 西堀 英治, 町田 尚紀, 坂田 誠, 下村 理

    日本物理学会講演概要集 53 (2) 638-638 1998年9月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  245. 26p-YF-8 La_3Ni_2O_<7-δ>の高圧X線構造解析

    金田 昌基, 原科 浩, 安井 幸夫, 佐藤 正俊, 西堀 英治, 州崎 昌宏, 坂田 誠, 高田 昌樹, 安達 隆文

    日本物理学会講演概要集 53 (2) 673-673 1998年9月5日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  246. 2a-R-1 BaCo_<1-x>Ni_xS_2の高圧下のX線散乱

    原科 浩, 佐々木 寿, 安井 幸夫, 佐藤 正俊, 坂田 誠, 西堀 英治, 池田 智宏, 高田 昌樹, 安達 隆文

    日本物理学会講演概要集 53 (1) 615-615 1998年3月10日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  247. 6p-F-8 MEMによるSrTiO_3低温相の電子密度分布

    小林 貴司, 池田 智宏, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集 52 (2) 127-127 1997年9月16日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  248. 7a-R-11 X線回折により求めたC15型Laves相MgCu_2の電子密度分布

    久保田 佳基, 高田 昌樹, 坂田 誠, 大庭 卓也, 木舩 弘一, 唯木 次男

    日本物理学会講演概要集 52 (2) 580-580 1997年9月16日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  249. 6a-D-7 Sc@C_82の金属内包構造

    西堀 英治, 高田 昌樹, 坂田 誠, 稲熊 正康, 篠原 久典

    日本物理学会講演概要集 52 (2) 279-279 1997年9月16日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  250. 31a-A-3 MEMによるKDP(KH_2PO_4)の電子密度分布II

    山村 滋典, 笠原 聡史, 高田 昌樹, 坂田 誠, 菅原 洋子

    日本物理学会講演概要集 52 (1) 387-387 1997年3月17日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  251. 29a-D-3 Sc_2@C_<84>の金属内包構造

    西堀 英治, 高田 昌樹, 坂田 誠, 山本 悦司, 篠原 久典

    日本物理学会講演概要集 52 (1) 272-272 1997年3月17日

    出版者・発行元:一般社団法人日本物理学会

    ISSN:1342-8349

  252. 29p-D-3 MEMによるLi_2CsC_<60>, K_2RbC_<60>, Rb_2CsC_<60>の電子密度分布

    高田 昌樹, 西堀 英治, 町田 尚紀, 坂田 誠, 谷垣 勝巳, 廣沢 一郎, 水木 純一郎

    日本物理学会講演概要集 52 279-279 1997年

    出版者・発行元:一般社団法人 日本物理学会

    DOI: 10.11316/jpsgaiyo.52.1.2.0_279_2  

  253. GaNの電子密度分布

    池田 智宏, 高田 昌樹, 坂田 誠, Dobrzynski L.

    日本物理学会講演概要集. 秋の分科会 1996 (2) 186-186 1996年9月13日

    出版者・発行元:一般社団法人日本物理学会

  254. 31p-X-12 プロトン伝導体SrCe_<0.95>Yb_<0.05>O_<3-α>の電子密度分布

    池田 智宏, 高田 昌樹, 坂田 誠, 岩原 弘育

    日本物理学会講演概要集. 年会 51 (2) 236-236 1996年3月15日

    出版者・発行元:一般社団法人日本物理学会

  255. Nd_2CuO_4のX線粉末回折パターンより求めた電子密度分布の解析

    小澤 哲也, 井添 克昭, 田崎 大祐, 熊沢 紳太郎, 石田 興太郎, 大隅 一政, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集. 秋の分科会 1995 (3) 435-435 1995年9月12日

    出版者・発行元:一般社団法人日本物理学会

  256. マキシマムエントロピー法によるPrBa_2Cu_3O_<7-δ>のPr-CuO_2混成軌道の直接観察

    坂田 誠, 高田 昌樹, 高山 崇, 樹神 克明, 佐藤 正俊

    日本物理学会講演概要集. 秋の分科会 1995 (3) 510-510 1995年9月12日

    出版者・発行元:一般社団法人日本物理学会

  257. 4a-X-9 MEMによるダイヤモンドおよびシリコンの電子密度

    高田 昌樹, 坂田 誠

    日本物理学会講演概要集. 秋の分科会 1994 (2) 459-459 1994年8月16日

    出版者・発行元:一般社団法人日本物理学会

  258. 4a-X-11 核密度分布より求めた非調和熱振動IV : 熱振動ポテンシャルの有効次数の決定

    熊沢 紳太郎, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集. 秋の分科会 1994 (2) 460-460 1994年8月16日

    出版者・発行元:一般社団法人日本物理学会

  259. 4a-X-10 六方晶窒化ホウ素の電子密度分布

    山村 滋典, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集. 秋の分科会 1994 (2) 460-460 1994年8月16日

    出版者・発行元:一般社団法人日本物理学会

  260. 2p-YF-7 MEMによるSrTiO_3の電子密度と核密度分布

    高田 昌樹, 高山 崇, 坂田 誠, Howard C.J

    日本物理学会講演概要集. 秋の分科会 1994 (2) 62-62 1994年8月16日

    出版者・発行元:一般社団法人日本物理学会

  261. 2a-S-4 X線回折によるアルカリ金属ドープC_60の電子密度

    久保田 佳基, 高田 昌樹, 梅田 文太郎, 坂田 誠, 廣沢 一郎, 水木 純一郎, 谷垣 勝巳

    日本物理学会講演概要集. 秋の分科会 1994 258-258 1994年

    出版者・発行元:一般社団法人 日本物理学会

    DOI: 10.11316/jpsgaiyoj.1994.2.0_258_2  

  262. 14p-DL-4 CeO_2の核密度分布と非調和熱振動

    熊沢 紳太郎, 高田 昌樹, 坂田 誠, Howard C.J.

    日本物理学会講演概要集. 秋の分科会 1993 (2) 604-604 1993年9月20日

    出版者・発行元:一般社団法人日本物理学会

  263. 14p-DL-2 マキシマムエントロピー法によるCs_3CoCl_5の偏極中性子回折データの解析

    高木 政博, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集. 秋の分科会 1993 (2) 603-603 1993年9月20日

    出版者・発行元:一般社団法人日本物理学会

  264. 30a-ZB-7 核密度分布から求めたルチル(TiO_2)の非調和熱振動の研究

    熊沢 紳太郎, 高田 昌樹, 坂田 誠

    日本物理学会講演概要集. 年会 48 (2) 503-503 1993年3月16日

    出版者・発行元:一般社団法人日本物理学会

  265. 30p-ZB-3 IPの粉末X線回折への応用

    坂田 誠, 高田 昌樹

    日本物理学会講演概要集. 年会 48 (2) 508-508 1993年3月16日

    出版者・発行元:一般社団法人日本物理学会

  266. 26p-T-7 マキシマム・エントロピー法によるbcc金属Wの電子密度分布

    久保田 佳基, 高田 昌樹, 阪田 誠

    秋の分科会講演予稿集 1992 (3) 223-223 1992年9月14日

    出版者・発行元:一般社団法人日本物理学会

  267. 25a-S-11 単結晶中性子回折データを用いたマキシマム・エントロピー法によるBeの熱振動の直接決定

    高田 昌樹, 坂田 誠, Larsen F.K, 久保田 佳基, Iversen B.B

    秋の分科会講演予稿集 1992 (2) 536-536 1992年9月14日

    出版者・発行元:一般社団法人日本物理学会

  268. 25a-S-10 マキシマムエントロピー法における近似法の解析

    熊沢 紳太郎, 高田 昌樹, 坂田 誠

    秋の分科会講演予稿集 1992 (2) 536-536 1992年9月14日

    出版者・発行元:一般社団法人日本物理学会

  269. 27a-ZG-6 X線回折によるZn微粒子の成長晶癖の研究

    高田 昌樹, 武市 晃洋, 井戸 あゆち, 坂田 誠, 原田 仁平, 虎谷 秀穂

    年会講演予稿集 46 (2) 3-3 1991年9月12日

    出版者・発行元:一般社団法人日本物理学会

  270. 27a-L-11 仮想X線顕微鏡の可能性

    坂田 誠, 高田 昌樹

    年会講演予稿集 46 (2) 481-481 1991年9月12日

    出版者・発行元:一般社団法人日本物理学会

  271. 27a-L-10 マキシマムエントロピー法による核密度分布について

    宇野 立也, 高田 昌樹, 坂田 誠

    年会講演予稿集 46 (2) 480-480 1991年9月12日

    出版者・発行元:一般社団法人日本物理学会

  272. 27a-ZE-4 hcp金属の電子密戸分布と層構造について

    久保田 佳基, 高田 昌樹, 坂田 誠

    年会講演予稿集 46 (3) 188-188 1991年9月12日

    出版者・発行元:一般社団法人日本物理学会

  273. 29p-BPS-23 C_<60>の放射光による粉末X線回折

    高田 昌樹, 久保田 佳基, 坂田 誠, 原田 仁平, 斉藤 弥八, 篠原 久典, 永島 英夫, 安藤 義則

    年会講演予稿集 46 (2) 428-428 1991年9月12日

    出版者・発行元:一般社団法人日本物理学会

  274. 4a-TA-7 放射光とIPの組合せによる粉末X線回折について

    山田 学, 高田 昌樹, 坂田 誠

    秋の分科会講演予稿集 1990 (2) 525-525 1990年9月12日

    出版者・発行元:一般社団法人日本物理学会

  275. 31p-PS-126 正方晶YBa_2Cu_3O_yのマキシマムエントロピー法により求めた電子密度分布について

    熊沢 紳太郎, 高田 昌樹, 坂田 誠, 石田 興太郎

    年会講演予稿集 45 (3) 288-288 1990年3月16日

    出版者・発行元:一般社団法人日本物理学会

  276. 31p-TJ-8 SiO_2ガラス中のCdS微粒子のX線回折による評価について

    高田 昌樹, 久保田 佳基, 坂田 誠, 原田 仁平, 野上 正行

    年会講演予稿集 45 (2) 480-480 1990年3月16日

    出版者・発行元:一般社団法人日本物理学会

  277. 31p-TJ-6 選択配向性のある粉末X線データのMEMによる解析

    坂田 誠, 熊沢 紳太郎, 高田 昌樹, 森 連太郎

    年会講演予稿集 45 (2) 479-479 1990年3月16日

    出版者・発行元:一般社団法人日本物理学会

  278. 5a-P-10 MEMによるab initio粉末構造解析の試み

    高田 昌樹, 森 連太郎, 久保田 佳基, 熊沢 紳太郎, 坂田 誠, 虎谷 秀穂

    秋の分科会講演予稿集 1989 (2) 469-469 1989年9月12日

    出版者・発行元:一般社団法人日本物理学会

︎全件表示 ︎最初の5件までを表示

書籍等出版物 11

  1. NanoTerasuの実験ホール非管理区域化への期待

    公益社団法人日本アイソトープ協会 2023年12月

  2. DX/GX時代のオープンイノベーションの拠点NanoTerasuの挑戦

    公益財団法人 石油学会 2023年6月

  3. POLYMERS 高分子 72巻 2月号 (2023年)

    公益財団法人 高分子学会 2023年2月

  4. 燃料電池 Vol.21 No.4 春号

    一般社団法人 燃料電池開発情報センター 2022年4月

  5. 「保全学」Vol.21-1(4月号)

    一般社団法人日本保全学会 2022年4月

  6. 「成形加工」34巻(2022年)3号

    高田 昌樹

    一般社団法人 プラスチック成形加工学会 2022年3月

  7. ポリマーの強靱化技術最前線 : 破壊機構、分子結合制御、しなやかタフポリマーの開発

    伊藤, 耕三, 高原, 淳, 原田, 明

    エヌ・ティー・エス 2020年5月

    ISBN: 9784860436681

  8. 公益社団法人日本磁気学会誌「まぐね」Vol.14, No.3, 128-132

    高田昌樹

    日本磁気学会 2019年6月

  9. 機能物質・材料開発と放射光 : SPring‐8の産業利用

    堀江 一之, 古宮 聡, 高田 昌樹

    シーエムシー出版 2014年

    ISBN: 9784781308869

  10. 機能物質・材料開発と放射光 : SPring‐8の産業利用 = R&D of functional substances and materials by using synchrotron radiation : industrial application of SPring‐8

    堀江 一之, 古宮 聰, 高田 昌樹

    シーエムシー出版 2008年

    ISBN: 9784781300405

  11. MEMとリートベルト法による新しい精密粉末構造解析システムの構築

    高田 昌樹

    [島根大学] 1998年

︎全件表示 ︎最初の5件までを表示

講演・口頭発表等 47

  1. 材料開発と描く、”ナノテラス”というミライ 招待有り

    高田 昌樹

    第19 回 日本セラミックス協会マテリアル・ファブリケーション &プロダクション・デザイン研究会 2024年3月29日

  2. 社会課題解決に資するナノテラス 招待有り

    高田 昌樹

    2024年第71回応用物理学会春季学術講演会T12 2024年3月24日

  3. 次世代放射光ナノテラスの非破壊評価における役割-ラボと施設の 多彩なプローブとの共創の視座から- 招待有り

    高田 昌樹

    第 14 回放射線による非破壊評価シンポジウム 2024年3月4日

  4. 再生プラスチックの循環性向上のための品質分析データバンク構築 招待有り

    高田 昌樹

    SIP第3期課題「サーキュラーエコノミーシステムの構築」第1回公開シンポジウム 2024年2月20日

  5. 次世代放射光 NanoTerasu(ナノテラス)による X 線評価技術の革新 招待有り

    高田 昌樹

    日本薬剤学会物性 FG セミナー 2023 X 線を用いた原薬・製剤の評価 2024年2月20日

  6. NanoTerasu(ナノテラス)の概要 - 先端研究基盤の産学共創活用の視座から - 招待有り

    高田 昌樹

    NMRプラットフォーム シンポジウム2023 2023年12月4日

  7. NanoTerasu:nice-to-haveではなく、must-haveの施設となるために 招待有り

    高田 昌樹

    極端紫外光研究施設40周年記念行事記念講演会 2023年12月1日

  8. 次世代放射光施設ナノテラスは地域産業活性化の切り札となりうるか? 招待有り

    高田 昌樹

    地域産業活性化研究会 2023 in 横浜 究極の光でナノを見る ~最先端の放射光施設の産業利用を考えよう~ 2023年11月28日

  9. NanoTerasu EcoSystem Genesis - Enlighten the Nano Universe to Drive a Sustainable World - 招待有り

    高田 昌樹

    MIRAI 2.0 R&I Week 2023 - Materials Science TEG 2023年11月15日

  10. 応用物理でイノベーションを変える次世代放射光 NanoTerasu 招待有り

    高田 昌樹

    東北大学工学部応用物理学科6 0 周年記念講演会 2023年11月11日

  11. The NanoTerasu doctrine -Building a new range of innovation ecosystem 招待有り

    高田 昌樹

    1st Workshop on the Chicago-Tohoku Quantum Alliance 2023年10月6日

  12. 科学と技術の先端をつなぎ、明日を拓くNanoTerasu(ナノテラス) 招待有り

    高田 昌樹

    日本物理学会・東北大学主催 市民科学講演会 「最先端の科学を仙台の地から」 2023年9月18日

  13. NanoTerasu の光源特性と触媒サイエンス 招待有り

    高田 昌樹

    第132 回触媒討論会 2023年9月13日

  14. 機能の可視化で複合材料の課題に挑むNanoTerasu(ナノテラス) 招待有り

    高田 昌樹

    日本複合材料学会 第48 回複合材料シンポジウム 2023年9月12日

  15. NanoTerasu(ナノテラス)と電気エネルギーシステム工学の未来 招待有り

    高田 昌樹

    工学セミナー学術講演会 2023年5月31日

  16. 次世代放射光施設NanoTerasuが拓く、新次元の半導体評価技術 招待有り

    高田 昌樹

    一般社団法人 ワイドギャップ半導体学会(WideG) 第 11 回研究会 2023年5月19日

  17. NanoTerasu: Next Generation Synchrotron Light Source in Japan 招待有り

    高田 昌樹

    INTERMAG2023 2023年5月17日

  18. 「NanoTerasu(ナノテラス):次世代放射光施設の概要 産学共創による医学生物学分野のへの新たな応用の開拓」 招待有り

    日本生理学会100周年記念大会 恒常性と持続可能性~生理学の次なる100年に向けて~ 2023年3月15日

  19. Update on the Japanese synchrotron Nanoterasu 招待有り

    高田 昌樹

    SMART-SOLID-Q-MAT Summer School 2023 2023年6月30日

  20. DX・GX時代のNanoTerasu(ナノテラス)活用 招待有り

    2022年電気化学会 東北支部・東海支部合同シンポジウム 2022年11月20日

  21. [NanoTerasu(ナノテラス)がもたらす放射光活用の革新」 招待有り

    2022年度 日本表面真空学会 中部支部研究会 『紫外・軟X線領域の放射光利用』 2022年11月5日

  22. 次世代放射光施設(NanoTerasu)の精密工学との共創 - ナノの可視化とコアリションが支援する DX・GX 時代の モノづくり - 招待有り

    2022 年度(公社)精密工学会秋季大会関連事業「新技術講演会-産学・産産連携への集い-」 2022年9月8日

  23. 「精密工学との協創が拓くイノベーションインフラとしての次世代放射光」 招待有り

    精密工学会東北支部 産官学出前塾 ~次世代放射光技術と精密工学~ 2022年4月22日

  24. "SLIT-J project - a unique collaboration between industry and public funding and utilization." 招待有り

    The 14th International Conference on Synchrotron Radiation Instrumentation (SRI 2021) 2022年4月1日

  25. Building a New Range of Digital Transformation(DX) in R&D - Perspective of Next Generation Synchrotron Radiation Facility - 招待有り

    IIT and NIMS Materials Science Workshop online meeting between IIT and NIMS 2021年12月7日

  26. 次世代放射光でレアメタル・イノベーションを起こせるか? 招待有り

    高田 昌樹

    第7回 レアメタル・グリーンイノベーション RaMGIフォーラム 2021年11月22日

  27. 結晶学のDX化が拓く次世代のイノベーション 招待有り

    高田 昌樹

    日本結晶学会創立70周年記念シンポジウム 2021年11月20日

  28. 放射光科学と最大エントロピー法による錯体構造化学の革新 招待有り

    高田 昌樹

    第71回錯体化学会討論会 2021年9月19日

  29. 次世代放射光の概要とコアリション 招待有り

    高田 昌樹

    東北大・九州大 次世代放射光シンポジウム2021 2021年8月20日

  30. Solving Reaction Infography Challenges by the next generation Synchrotron Radiation Facility 招待有り

    Masaki Takata

    The 3rd Workshop of the Reaction Infography (R-ing) Unit 2020年12月10日

  31. 先端科学技術基盤の社会的責任 招待有り

    高田 昌樹

    科学技術社会論学会 第19回年次研究大会 神戸大学実行委員会企画1 放射光科学とサイエンス・ベースド・イノベーション 2020年12月5日

  32. 次世代放射光が拓く、データ科学時代のコロイド科学 招待有り

    第71回コロイドおよび界面化学討論会 2020年9月15日

  33. 次世代放射光施設の概要 招待有り

    高田 昌樹

    資源・素材学会2020 企画講演 未来のひかり ~次世代放射光~ 2020年9月9日

  34. コウリションステーションの整備構想 招待有り

    高田 昌樹

    第33回日本放射光学会年会 放射光科学合同シンポジウム企画講演2 2020年1月11日

  35. 放射光X線回折データとマキシマムエントロピー法を用いたナイロン6結晶構造の分子間水素結合の可視化の検討

    長尾美穂, 山本淳記, 櫻井伸一, 櫻井伸一, 加藤健一, 高田昌樹, 高田昌樹, 佐々木園, 佐々木園, 佐々木園

    繊維学会予稿集 2018年11月1日

  36. 広角/小角X線散乱測定を用いた張力下のフレミオン膜の構造変化の可視化

    藤波想, 星野大樹, 仲谷友孝, 高田昌樹, 高田昌樹

    高分子学会予稿集(CD-ROM) 2018年8月29日

  37. SAXSとRMCモデリングによる伸長時のゴム中シリカ粒子の分散状態評価

    仲谷友孝, 小原真司, 小原真司, 星野大樹, 藤波想, 高田昌樹, 高田昌樹

    高分子学会予稿集(CD-ROM) 2018年8月29日

  38. 放射光X線回折データとマキシマムエントロピー法によるナイロン6結晶構造の電子密度マッピングの検討

    長尾美穂, 山本淳記, 加藤健一, 高田昌樹, 高田昌樹, 櫻井伸一, 櫻井伸一, 佐々木園, 佐々木園, 佐々木園

    高分子学会予稿集(CD-ROM) 2018年8月29日

  39. マキシマムエントロピー法と粉末X線回折法に基づくポリ(3‐ハイドロキシブチレート)のパラクリスタル構造の電子密度分布イメージング法の確立

    山本淳記, 合田真美, AMRAN Hossain Md, 櫻井伸一, 櫻井伸一, 加藤健一, 高田昌樹, 佐々木園, 佐々木園, 佐々木園

    高分子学会予稿集(CD-ROM) 2018年5月8日

  40. ポリ(3‐ヒドロキシブチレート‐co‐3‐ヒドロキシヘキサノエート)薄膜で形成される微結晶のEdge‐on/Flat‐on型配向性とその影響因子の検討

    合田真美, 櫻井伸一, 櫻井伸一, 山根秀樹, 山根秀樹, 増永啓康, 引間孝明, 高田昌樹, 高田昌樹, 平井智康, 高原淳, 佐々木園, 佐々木園, 佐々木園

    高分子学会予稿集(CD-ROM) 2018年5月8日

  41. 小角/広角X線散乱による伸長されたフレミオン膜の内部構造変化の観察

    藤波想, 星野大樹, 仲谷友孝, 高田昌樹, 高田昌樹

    高分子学会予稿集(CD-ROM) 2018年5月8日

  42. 逆モンテカルロ法を用いた延伸中でのゴム中シリカ粒子の分散状態評価

    仲谷友孝, 小原真司, 小原真司, 星野大樹, 藤波想, 高田昌樹, 高田昌樹

    高分子学会予稿集(CD-ROM) 2018年5月8日

  43. スピンコート成膜過程におけるポリ(ε‐カプロラクトン)の構造形成キネティクスの解明

    PARK Jinkyu, 宮元駿, 合田真美, AMRAN Hossain Md, 櫻井伸一, 増永啓康, 引間孝明, 高田昌樹, 高田昌樹, 佐々木園, 佐々木園

    高分子学会予稿集(CD-ROM) 2018年5月8日

  44. 音波浮遊溶融法を用いた高秩序な分子自己集合体の形成

    田中大喜, 梶谷孝, 梶谷孝, 尾原幸治, 大隅寛幸, 高田昌樹, 高田昌樹, 福島孝典

    日本化学会春季年会講演予稿集(CD-ROM) 2018年3月6日

  45. ディスコティックカラムナー液晶の巨視的力学応答

    梶谷孝, 梶谷孝, 小林美貴, 高田昌樹, 高田昌樹, 福島孝典

    日本化学会春季年会講演予稿集(CD-ROM) 2018年3月6日

  46. EUV結像系用の曲面多層膜ミラーで生じる色収差とその補正法

    金子明誉, 豊田光紀, 高田昌樹

    応用物理学会春季学術講演会講演予稿集(CD-ROM) 2018年3月5日

  47. 回折限界EUV結像を実現するアクロマティックEUV多層膜ミラーの開発

    金子明誉, 豊田光紀, 高田昌樹

    応用物理学会春季学術講演会講演予稿集(CD-ROM) 2018年3月5日

︎全件表示 ︎最初の5件までを表示

産業財産権 13

  1. MEM構造解析により価電子密度分布を求める方法

    田中 宏志, 高田 昌樹

    産業財産権の種類: 特許権

  2. 構造因子テンソル要素決定法及びそのためのX線回折装置利用法

    大隅 寛幸, 高田 昌樹, 壽榮松 宏仁, 藤縄 剛

    産業財産権の種類: 特許権

  3. X線検出装置及び粉末X線回折測定方法

    田中 義人, 久保田 佳基, 黒岩 芳弘, 高田 昌樹, 北川 進

    産業財産権の種類: 特許権

  4. 微細物性加工方法および微細物性加工装置

    守友 浩, 金 廷恩, 加藤 健一, 高田 昌樹

    特許第5243741号

    産業財産権の種類: 特許権

  5. 結晶物質のX線回折データのMEM構造解析により静電ポテンシャルを実験的に求める方法

    田中 宏志, 高田 昌樹

    特許第4827444号

    産業財産権の種類: 特許権

  6. 微小試料挿入容器、微小試料装着治具、X線回折装置、微小試料挿入容器の形成方法、および微小試料装着方法

    岸 證, 高田 昌樹, 小林 達生

    産業財産権の種類: 特許権

  7. 微小試料装着構造とその方法

    岸 證, 高田 昌樹, 小林 達生

    特許第4453821号

    産業財産権の種類: 特許権

  8. 構造因子テンソル要素決定法及びそのためのX線回折装置利用法

    大隅 寛幸, 高田 昌樹, 壽榮松 宏仁, 藤縄 剛

    特許第4578832号

    産業財産権の種類: 特許権

  9. 試料ホルダ及びX線装置

    原田 仁平, 西堀 英治, 涌井 義一, 熊澤 克芳, 鷲見 高雄, 小塚 基樹, 高田 昌樹, 坂田 誠

    産業財産権の種類: 特許権

  10. 物質構造の精密構造解析方法、プログラム、システムおよび物質の製造方法

    田中 宏志, 坂田 誠, 高田 昌樹, 西堀 英治, 原田 仁平, 中川 敦史, 大谷 孝之

    産業財産権の種類: 特許権

  11. 物質の精密構造解析方法

    田中 宏志, 坂田 誠, 高田 昌樹, 西堀 英治, 原田 仁平, 中川 敦史, 大谷 孝之

    特許第3891338号

    産業財産権の種類: 特許権

  12. 1次元または2次元検出器を用いた粉末X線回折データ測定方法

    高田 昌樹, 西堀 英治, 坂田 誠, 原田 仁平

    産業財産権の種類: 特許権

  13. X線回折計測装置

    西堀 英治, 高田 昌樹, 坂田 誠, 原田 仁平, 梅垣 志朗, 澤野 成民

    産業財産権の種類: 特許権

︎全件表示 ︎最初の5件までを表示

共同研究・競争的資金等の研究課題 24

  1. ビッグサイエンスと産業イノベーション:科学化される社会、社会化される科学

    桑田 耕太郎, 松嶋 登, 石川 哲也, 高田 昌樹, 原 拓志, 高尾 義明, 松尾 隆, 井上 福子, 高橋 勅徳, 西村 孝史, 水越 康介, 宮尾 学

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Tokyo Metropolitan University

    2015年4月1日 ~ 2020年3月31日

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    本研究の目的は、所与の科学技術を産業利用する既存のイノベーション研究ではなく、科学技術の変化や産業構造の変化を伴った根源的なイノベーションのプロ セスを理解するための分析枠組みと理論を構築し、先端科学技術と産業の国際競争力の向上をダイナミックに結びつける理論と方法を確立することにある。 ビッ グサイエンスのリサーチサイトとして、理化学研究所の協力の下、大型放射光施設(SACLAやSPring-8)を取り上げ、多角的な分析を行った。

  2. 錯体ナノ空間の動的特性を利用した光・吸着エネルギー変換物質の創製

    松田 亮太郎, 佐藤 弘志, 佐藤 治, 高坂 亘, 田中 秀樹, 高田 昌樹, 堀 彰宏

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (A)

    研究種目:Grant-in-Aid for Young Scientists (A)

    研究機関:Nagoya University

    2016年4月1日 ~ 2019年3月31日

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    金属と有機配位子からなる多孔性配位高分子(PCP)を基盤とした、光による分子吸着が可能な多孔性材料の開発と機能探索を行った。その結果、光によって構造変換を誘起し、それに基づく吸着機能の制御が可能な新しい物質の開発に成功した。また、光刺激でカルベンなどの非常に活性な化学種をナノ空間内に発生させることが可能な新しい物質も合成した。これらの物質は発生させた活性種とゲスト分子との相互作用によって選択的な分子吸着が可能である事がわかった。本研究により、圧力や温度だけでなく光によって分子吸着を実現するナノ空間材料の設計が可能であることを示すことができた。

  3. 過冷却液体からの金属ガラス生成過程の直接観察

    小原 真司, 高田 昌樹, 渡邉 匡人, 水野 章敏

    2006年 ~ 2007年

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    本年度は、金属ガラス融体および過冷却液体の構造データを得るために開発した液体試料を無容器で不活性ガスで浮遊させる装置は長時間試料を安定に浮遊させる技術、ノウハウが確立し、安定して実験できるようになった.そして、SPring-8における高エネルギー放射光を用いた一連の回折実験から金属ガラスになる液体(Zr-Cu合金,Zr-Ni合金)およびならない液体(Zr-P合金)の構造解析を行い、金属ガラスにならない液体はその原子配列がまったくランダムであるが、金属ガラスになる液体はある種の秩序が存在することを実験的に明らかにした.さらにこの秩序はZr-Cu合金とZr-Ni合金では液体状態においてもガラスにおける両者の構造の差と同様に、明確に異なっており、Zr-Ni合金においては化学的な短距離秩序が存在していることが示唆された.詳細な構造解析は逆モンテカルロシミュレーションおよび経験的ポテンシャルを用いたシミュレーションを併用して現在も行っており、これらの成果をまとめて論文にする予定である. また、金属融体が過冷却液体を経て結晶化する過程を高速二次元検出器を用いて最高で20msecの時間分解能で捉える環境を整えた.そして、Zr-Cu合金、Zr-Ni合金、Zr-Cu-Al合金、Zr-Ni-Al合金が液体から過冷却液体を経て凝固する際のX線回折パターンの違いをリアルタイムで検出し、さらに、過冷却液体中に析出する結晶核の分散の差および結晶粒径が各合金において異なることを示した.凝固過程の実験は今後も継続して行うことにより、合金の差による系統的な差が明確にできると考えている.

  4. 分子導入されたナノ機能空間の電子密度レベルでの構造

    高田 昌樹, 久保田 佳基, 加藤 健一, 大石 泰生, 田中 宏志, 安達 隆文

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas

    研究種目:Grant-in-Aid for Scientific Research on Priority Areas

    2004年 ~ 2007年

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    多孔性金属錯体は、その規則配列したナノ細孔内に分子を導入、整列させることにより、これまでにない特異な凝集状態の実現や、そこから生まれる機能を利用した新材料開発への展開が期待されている。この様な研究の中で、ゲスト分子導入機構の解明は大変重要であり、そのためにホストの骨格構造とともにゲスト分子の精緻な構造情報は必要不可欠である。更に、原子配列のみならず、物性を担う電子分布の情報は、これらの物質をベースにした新機能材料の開発を推進していくためのボトムアップ化学にとって極めて重要である。本研究では、SPring-8の高輝度放射光とMEM(マキシマム・エントロピー法)/Rietveld法を利用し、CPL-1と呼ばれる多孔性金属錯体を中心として種々のガス分子の吸着構造を明らかにした。 水素吸着では、水素分子が細孔壁との弱い相互作用によって吸着され、出し入れが容易な状態にあることがわかった。そして、金属-酸素ユニットが水素分子を誘引する効果を持つこと、細孔壁の形状や大きさが水素分子とフィットすることが重要であることが示唆された。 アセチレン吸着では、分子が細孔壁の酸素と水素結合を形成しながら、両端から捉えられている様子が電子密度分布にクリアに視覚化された。この結合により、アセチレン分子は特異な選択的吸着能を示し、安定かつ超高密度な濃縮が実現されていると考えられる。更に、アセチレンの吸着では、世界に先駆けて吸着過程の中間状態の構造解明に成功した。 また、実験的電子密度分布に基づく静電ポテンシャル可視化法を開発し、その手法がゲストーホスト間の静電的相互作用の理解において有用であることを示した。 本研究により得られた、細孔内でのガス分子の配列や結合状態などの精緻な構造情報は、より優れた特性を持つ新規機能性多孔性金属錯体の設計指針を与え、ボトムアップナノ機能空間の創成に貢献できるものと考えられる。

  5. 放射光粉末構造解析による光励起状態の構造決定

    守友 浩, 加藤 健一, 上岡 隼人, 高田 昌樹

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S)

    研究種目:Grant-in-Aid for Scientific Research (S)

    2003年 ~ 2007年

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    本研究の目的は、時間分解分光等により遷移金属錯体の光誘起現象を探索するとともに、第三世代放射光X線を利用して、構造物性の立場から遷移金属錯体の光誘起現象を明らかにすることである。そのために、偏向電磁石ビームラインでは光照射下での構造解析を行い、アンジュレータービームラインでは時間分解X線回折装置を建設した。主要な研究成果を以下に列挙する。 (1) [Fe(ptz)_6](BF_4)_2において、動的平衡状態(光励起と熱緩和が釣り合った定常状態)の一次相転移を発見した。さらに、この動的相転移の時間発展を詳細に解析し、光誘起された高スピンサイトの化学圧力が重要な役割を担っていることを明らかにした。 (2) [Fe(phen)_2](NCS)_2において、オン/オフスイッチの実現した。さらに、それぞれの状態の電子レベルでの構造解析に成功した。 (3) 層状反強磁性体LaMnO_3にスピン系の光応答を調べ、臨界緩和現象の消失を確認した。 (4) BL40XUビームラインに時間分解X線回折装置を建設した。 (5) RbMn[Fe(CN)_6]の電子レベルの構造解析に成功した。さらに、静電ポテンシャル法により価数状態を明らかにした。 (6) 価数制御されたCo-Feシアノ架橋金属錯体膜を作成し、電子相図を完成した。 (7) フェムト秒時間分解分光により、CT状態の寿命増大効果を発見した。

  6. 金属ガラスの大過冷却状態の原子レベルでの直接観察

    小原 真司, 高田 昌樹, 渡邉 匡人, 水野 章敏

    2004年 ~ 2005年

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    本年度は、金属ガラス融体および過冷却液体の構造データを得るために、ガスジェット浮遊装置の各種パラーメータ(ノズルの形状、ガスの流量、およびガスの純度)を最適化することができた。金属融体試料をアルゴンガスで浮遊させ、炭酸ガスレーザーによる加熱で融体としているために、ガスおよび配管に存在する不純物の影響による酸化が実験当初は観測された。そこで、超高純度ガスを採用し、かつ配管をステンレス製のものとし、なるべくその長さを短くした。その結果、世界で初めて金属ガラス融体をガスジェット浮遊法で長時間安定に浮遊させることに成功した。その結果、SPring-8の高エネルギー放射光を用いることで非常に高精度の高い回折データを広い波数ベクトルの範囲で短時間で測定することに成功した。さらに、得られたデータに逆モンテカルロシミュレーションと呼ばれるコンピュータシミュレーションを適用することにより、その3次元構造の可視化に成功した。得られた結果から金属ガラス融体とガラスの構造の類似性および融体の構造の特徴を浮き彫りにすることができた。さらに異なった組成の金属ガラス融体においても実験を行い、金属ガラス融体の構造に及ぼす組成の影響も系統的に捕らえるに至った。しかしながら、金属ガラス融体を過冷却液体として安定に長時間維持することは出来なかった。これは実験に用いた試料サイズが外径2mmと大きすぎたために融体の温度を下げていった際に核生成が促進され、結晶化が起こったためと考えられる。今後は試料サイズを外径1mmとして、さらに実験を継続して、融体が過冷却液体→ガラスとなる過程をリアルタイムで測定する必要がある。

  7. GAとMEMの統合によるAb intio電子解析システムの構築

    坂田 誠, 西堀 英治, 青柳 忍, 高田 昌樹, 久保田 佳基, 加藤 健一

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Nagoya University

    2003年 ~ 2005年

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    GA(遺伝的アルゴリズム)は、自然界における生物の適応性を数学的モデルにより表したアルゴリズムであり、スキーマと呼ばれる概念が最も重要になる。スキーマとは、一言で言えば環境に適応する良い遺伝子のことである。超多重度を有する系では、何が最適であるかを見出すこと、あるいは最適であることを証明することは、極めて困難である。それ故、複雑なプロセスに対して適応的解を見つける必要性が高くなる。GAは、この様な問題には非常に適したアルゴリズムである。 しかしながら、本研究では適応的解では役に立たない。本研究では、スキーマを見つけて適応解を見つけ、その適応解の中から構造精密化を行い、最適解を得なければならない。いわば適応的解を最適解に成長させる必要がある。成長プロセスで、MEM(マキシマム・エントロピー法)が極めて強力な方法を提供すると予想していたが、本研究を進めていく過程でMEMそのままではなく、MEMを発展させた差分MEM(DMEM)が非常に強力な方法であることが分かった。 DMEMには、いくつかのレベルがある。大きく分けて、全ての原子を仮定した構造モデルより計算される結晶構造因子と観測結晶構造因子との差分により電子密度分布を計算する場合と、構造モデルの一部を取り除いた不完全な構造モデルとの差分電子密度分布を計算する2つがある。これらは、何を精密化するかにより使い分ける必要がある。例えば、対象とする物質が、秩序が乱れたDisorder構造をとる場合は、Disorderを示すと思われる部分を取り除いた電子密度分布を描くDMEMが有効性を発揮する。これまでの方法では、粉末試料のAb initio解析でDisorderを解明することは困難であった。本研究よりその様な場合でも、どのように対処すればよいかが分かった。これは、本研究を実施して得られた大きな成果で、この様な方法論的発展の上に、比較的大きな分子から構成される医薬品などにおいても、極めて精度の高い構造解析が可能となった。

  8. 放射光による単分子イメージングの基礎技術の開発

    坂田 誠, 西堀 英治, 高田 昌樹

    2002年 ~ 2004年

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    これまで、結晶物質に対しては情報理論より発達した最も高度なイメージング手法である、マキシマムエントロピー法(MEM)を利用した「X線回折データのイメージング法」開発された。この方法は、原子レベルを上回り電子をイメージングしているので、分子・原子・電子を取り扱う物質科学としては最高レベルのイメージング手法である。しかし、現在の「X線回折データのイメージング法」には、2つの大きな欠点がある。第1は、結晶物質であっても全く構造が知られていない未知構造の物質である場合、X線回折データの可視化をすることが出来ない。第2は、対象とする物質が結晶ではなく非結晶性物質であったり、結晶化するほどたくさんの原子・分子が存在しなかったりする場合である。本研究は、第2の問題を解決する一助として企てた研究である。 研究の主要な目標としては、将来性を考えX線領域の自由電子レーザーが実用化された時に必要とされる技術を目指した。それ故、単分子などの非晶質体の構造決定プログラムを開発することとした。そのプログラムの中にMEMのアルゴリズムを組み込むこととした。単分子の場合でも、電子レベルでのイメージングには、MEMが最も適していることは疑問の余地がないと考えた結果である。 現在、プログラムの開発は終了し、実用に供される段階にある。それを実証する為に、まず、フラーレン1分子の場合のシミュレーションを行い、これまでのフーリエ法を使用する場合に比べて、良好なイメージングを行うことが出来ることを確認した。さらに、シミュレーションではなく収束電子線回折により測定されたカーボンナノチューブの回折パターンを用いて、イメージングを行い、本研究で開発した方法が有効であることを示した。 本研究は、萌芽的研究である為本格的な研究成果は今後の研究動向を待たなければならないが、コヒーレントビームの必要性を先駆的に示した点が大きな成果と考えている。

  9. ピーポッドの形態と内包される金属・分子内包フラーレンの分子構造

    高田 昌樹, 加藤 健一, 篠原 久典, 坂田 誠, 西堀 英治

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    2002年 ~ 2003年

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    本研究の目的は、ピーポッドを形成するナノチューブに内包される金属・分子内包フラーレンの電子密度レベルでの構造を、放射光精密構造解析によって明らかにすることであった。それによって、チューブ内での金属・分子内包フラーレン間または、チューブとの相互作用を、チューブとフラーレンの種類によって系統的に明らかにし、ピーポッドの構造形態との相関を構築をめざした。研究手法としては放射光を用いたX線粉末回折データをMEMにより解析し、フラーレン化合物の電子密度レベルでの更なる精密な構造を明らかにする。本研究では、実験法、解析法の改良と共に、様々な金属内包フラーレンの特徴ある構造を明らかにした。その中でも、金属内包フラーレンピーポッドに用いられるGd@C_<82>の構造を明らかにしたことは大きな成果である。この物質は、従来の他の金属内包フラーレンとは全く異なる構造をしており、理論計算による予測とも大きく異なっていた。そのほかにY_2@C_<82>,Y_2C_2@C_<82>等の構造を明らかにすると共に新しい理論計算の手法によりLa_2@C_<80>の特異な内包構造の起源を明らかにできたことは大きな成果である。また、実験法、解析手法は、ナノポーラス構造への分子閉じ込めの構造解明の手法へと発展させることもできた。

  10. Ag(001)単結晶表面上の2次元Ag-Na合金のX線精密構造物性

    坂田 修身, 北野 彰子, 高田 昌樹, 今井 康彦

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Japan Synchrotron Radiation Research institute

    2002年 ~ 2003年

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    超高真空中に置かれた、温度25KにおけるAg(001)単結晶表面(試料I)、および、2次元Ag-Naの構造(試料II)をSPring-8、表面界面ビームラインBL13XUのX線を用いて調べ、その表面構造に関する知見を得た。 超高真空槽内でアルゴンスパッタリングと試料加熱(500Kから800Kまで徐々に加熱)の組合せを40サイクル繰り返し、Ag(001)単結晶表面の不純物を取り除き、清浄化した、低速電子線回折のスポットの大きさから、表面の結晶性を評価する方法を用い、各サイクル終了後、表面結晶ドメインサイズを評価した。最大ドメインサイズをX線測定の試料I、試料IIのNa蒸着前の状態とした。0.1nmの波長をもつ単色X線を用いた。結晶表面の2次元性のため、逆格子空間において結晶表面のブラッグ回折条件は、バルク結晶のブラッグ点を中心に試料表面法線方向にのびる棒状散乱(CTR)となる。複数のCTR(11L,20L,13L,22L,42L)に沿って、回折X線強度曲線を測定した。(Lはほぼ結晶表面に垂直方向であり、その方向の入射X線と回折X線の運動量変化を試料の格子定数を使って表現したもの。)この実験強度曲線に偏光X線補正、ローレンツ補正、表面におけるX線の照射面積補正を施した後、表面の原子構造モデルを仮定した計算強度曲線と比較した。その結果、表面第1層Agと第2層Agの間隔がバルクAgの面間隔の0.54%収縮していることを明らかにした。また、表面結晶ドメインサイズは約80nmであった。Na蒸着後、試料IIについて同様な方法で実験し、その結果(表面にインコメンシュレート相が存在する可能性)を解析中である。 さらに、高エネルギーX線回折を用いた、迅速X線構造評価法を開発し、実際にその方法を適用しNiOナノワイヤのナノメータスケール構造を評価した。

  11. 電子の関与した機能材料開発のための新しい構造解析システムの開発

    坂田 誠, 高田 昌樹, 西堀 英治, 原田 仁平, 田中 宏志

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Nagoya Univercity

    2000年 ~ 2002年

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    本研究により、電子の関与した機能材料開発のための新しい構造解析システムに関する研究として、大きな成果を挙げることが出来た。新しい構造解析システムの中心的コンポーネントであるMEM/Rietveld(マキシマムエントロピー解析/リートヴェルト解析)法を完全に実用化レベルまで引き上げることができた。現在、本研究により開発されたプログラムは使用を希望する研究者に無料で配布している。そのプログラム使った成果が、色々な学会で日常的に発表されていると言う段階になった。 プログラムの開発を終えただけでなく、本研究において、種々の機能材料の構造解析に成功した。 第一のカテゴリーに属する物質群は、金属内包フラーレンなどのフラーレン化合物である。金属内包フラーレンには、1個の金属を内包するフラーレンあるいは2個の金属を内包するフラーレンなど金属の種類も考えると極めて多彩な種類が存在する。現在までに、本研究により10個以上の金属内包フラーレンの構造解析に成功している。金属内包フラーレンは、実用的にも極めて注目度の高い物質であり、大きな成果と自負している。 第二のカテゴリーに属する物質群は、多孔性空間をもつ金属錯体の構造解析である。近年、有機分子の設計性を最大限に活用して多彩な相互作用点を持つ化学側壁を合成し、高活性で特異的な機能を発現しうる金属錯体分子が注目を集めている。また、このミクロサイズ空間に種々のガス分子を吸着させ、実用的な利用も考えられ始めている。しかしながら、多孔性空間をもつ金属錯体において、結晶構造中に本当に取り込まれているのか、もし、取り込まれているなら結晶中のどこに取り込まれているのか、あるいは、表面に吸着されているだけなのか、何も分かっていなかった。 本研究により、ガス分子が物理吸着している様子が、極めて明瞭に示された。 この様な成功により、1年早く次の研究に進むことが出来た。

  12. MEMによるフラーレン化合物の電子密度レベルでの構造研究

    高田 昌樹, 西堀 英治, 坂田 誠

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas (A)

    研究種目:Grant-in-Aid for Scientific Research on Priority Areas (A)

    研究機関:Nagoya University

    1999年 ~ 2000年

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    本研究により、世界ではじめて、孤立五員環則(IPR)を破る金属内包フラーレンSc_2@C_<66>の構造決定に成功し、IPRの破られ方と内包した金属との関係を明らかにすることができた。これまで、IPRを破るフラーレンの安定構造については、理論計算によっても、色々予測されていたが、本研究により、内包された2個の金属原子がダイマーを形成し、それが内包されている安定位置に隣り合った五員環が存在していることが新事実として明らかになった。このことは、金属を内包することが、IPRを破るフラーレンを創り出すことにとって重要な要素である事を示している。この研究成果は、英国の科学雑誌、Natureに掲載された。その他、Sc2C2を内包するSc2C2@C84の構造も決定することに成功しドイツの化学雑誌Angewandte ChemieにMost Important Paperとして掲載された。また得られた電子密度と構造モデルは、その雑誌の表紙も飾った。さらに、C_<70>分子をベースとするフラーレン化合物についても構造を明らかにし論文投稿中である。研究を行っている。

  13. マキシマム・エントロピー法によるフラーレン化合物の精密構造解析

    坂田 誠, 西堀 英治, 高田 昌樹, 篠原 久典

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Nagoya University

    1996年 ~ 1999年

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    昨年度までの研究で、フラーレン・ケージに同一金属が1個、2個あるいは3個内包した時の構造を、実験的に明らかにすることに成功したので、本年度は研究の集大成として、金属内包フラーレンの構造安定性に対する一般的法則の発見に努めた。その結果、フラーレン・ケージ自身として安定な場合には、ほとんど、金属内包フラーレンは生成されず、フラーレン・ケージ自身としては不安定で金属原子が内包して初めて安定化する場合に、金属内包フラーレンが生成されることを見出した。また、フラーレン・ケージ自身としても不安定で、かつ、金属原子を内包することにより安定化出来ない多くのフラーレンが存在することも明らかになった。これにより、何故、フラーレンとして安定なC_<60>では、金属内包フラーレンの生成が著しく困難で有るのかと言う基本的な問題を明確に理解することができた。金属内包フラーレンに関しては、本研究終了後の更なる展望を踏まえ、IPR(Isolated Pentagon Rule)に従わない、フラーレンの探索を行っている。 本年度も、金属内包フラーレン以外のフラーレン化合物としては、アルカリ・ドープフラーレンの系統的構造研究を、さらに進展させた。その結果、超伝導転移温度の異なる4種類の物質について構造を解明した。それにより、(1)超伝導を示すアルカリ金属からフラーレンは、全て、フラーレン・ケージが自由回転を禁止されており、ドープした金属原子とフラーレン・ケージの相互作用が大きいこと、(2)ドープした金属原子からフラーレン・ケージへの電荷移動の量が大きいほど、超伝導転移温度が高くなること、が判明した。以上見るように、本研究により、フラーレン化合物、特に、金属内包フラーレンおよびアルカリ・ドープフラーレンに関して、多くの重要な知見が得られた。

  14. 相変態近傍での微視的構造変化の可視化

    高田 昌樹, 西堀 英治

    1998年 ~ 1998年

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    我々の研究グループでは、マキシマム・エントロピー法(MEM)による精密結晶構造解析を用いて、温度変化等による構造変化を回折データからモデルフリーに実空間に可視化するシステムを構築し、相変態の機構解明の実験的手法の一つとして確立することを目標とした。そして、金属内包フラーレン、高圧下での強相関化合物の構造変化、マンガン酸化物の常磁性、反強磁性相変態に伴う軌道整列の直接観察を試みた。例えば、、マンガン酸化物の研究成果については、以下の通りである。 層状ペロフスカイト型マンガン酸化物であるNdSr_2Mn_2O_7は150K以下で層状な反強磁性磁気構造となる。この結晶中のMn^<3+>イオンは4つの3d電子を持ち,dε^3dγ^1の電子配置をとる。前者はt_<2g>軌道と呼ばれ後者はe_g軌道と呼ばれる。このe_g軌道が酸素の2p軌道と混成軌道を形成する。NdSr_2Mn_2O_7の反強磁性相においてe_g電子は,2次元的なdx^2-y^2軌道と1次元的なd3z^2-r^2軌道のうち,dx^2-y^2軌道を占有すると言われている。その結果150K以下でMn-Oの結合に異方性があらわれると考えられる。これまで,この系に関してスピン秩序は中性子磁気回折実験により直接観測されてきた。しかし,軌道電子に関しては直接的な観測はほとんどされてこなかった。本研究で、MEMによりNdSr_2Mn_2O_7の面内方向と面間方向でのMn-O間の混成軌道による電子密度分布を直接観測し,室温と低温において実際に軌道の異方性が存在する事を明らかにする事に成功した。

  15. 差分MEMによるプロトン導伝体中のプロトン移動経路の解明

    坂田 誠, 高田 昌樹

    1997年 ~ 1997年

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    差分MEM法を固体イオニクスに適用し、固体内でのイオンの高速移動経路を解明する為に、2種類の組成の異なる試料、即ち、高温においてプロトン導電性を顕著に示すSrCe_<0.95>Yb_<0.05>O_<3-α>およびプロトン導電性をほとんど示さないSrCeO_3の微小構造変化を差分MEMにより明らかにした。放射光粉末回折実験は、高エネルギー加速器機構放射光施設BL3Aに設置されたX線回折装置により行い、精密なX線粉末回折データ収集した。実験により得られたX線回折データはマキシマムエントロピー法とリ-トヴェルト法を組み合わせた方法により解析した。MEM電子密度より、Ce(Yb)-O間に共有結合が存在することが分かった。この様な化学結合状態は、代表的なペロブスカイト型酸化物SrTiO_3と基本的に同じである。結合状態とは別に、Ce(Yb)が非常に特徴的な電子密度分布を示すことが興味深い。Ybの置換により、ある種のDisorder状態が実現し、この様な特徴的な電子密度分布を示すのかも知れない。立方晶の理想的ペロブスカイトでは対称性の要求により必ず対称的であるCe(Yb)-O結合に対して、非対称な電子密度分布をすることも分かった。TetragonalityあるいはOrthrhombicityを電子密度レベルで判断できることを意味し大変興味深い。基準状態として選んだSrCeO_3との差分MEM電子密度からは、Ce(Yb)サイトの構造変だけでなく、純粋な原子の置換では影響を受けないはずの、酸素の差分電子密度分布に非常に興味のある変形が存在することがわかった。即ち、Ybの置換により直接的影響を受けないはづの酸素が、非常に大きなSkewnessが生じている。この様なSkewnessによる静電効果によりプロトンが引きけられ、ホッピングが起こるという可能性もあり、プロトン伝導との関連が非常に興味深い。

  16. MEMとリ-トベルト法による新しい精密粉末構造解析システムの構築

    高田 昌樹, 山田 裕, 熊沢 紳太郎, 坂田 誠

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    1995年 ~ 1997年

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    これまで、X線及び中性子粉末結晶構造解析は、その物質の興味ある物性の発現機構を理解し、制御する上で、重要な構造情報を提供するものと考えられてきた。特に、酸化物高温超伝導体を始めとする様々な新物質の結晶構造を決定したリ-トベルト解析の果たした役割は大きい。しかし、リ-トベルト解析によって明らかにされる構造は、原子の集合体としての構造、すなわち原子配列である。従って、物質内の電子密度分布や原子核密度分布から得られる原子の結合状態や非調和熱振動といった、物性研究に、より直接的に関わってくる詳細な構造情報まで得ることはできない。元来、そのような情報は、X線、中性子線粉末回折データに含まれているはずである。 これまで、我々は、マキシマムエントロピー法(MEM)という新しい精密構造解析法を開発し、精密な電子密度及び原子核密度分布を回折データから求める方法を確立してきた。本研究は、MEMの可能性をさらに拡張し、また、従来の解析法であるリ-トベルト解析法の利点を生かすことにより、これまでの結晶学の限界を押し広げ、新たな結晶学を構築することを目的としている。その為に、MEMとリ-トベルト解析法を組み合わせた新しい粉末精密構造解析の方法論の確立を目指して、平成7年度より研究が開始された。幸いにも、初年度に、本研究で開発された方法を用いて、世界で初めて金属内包フラーレンの構造解析に成功した。この成果は科学雑誌Nature(377(1995)46-49)に掲載され、新聞各紙(日本経済新聞、日刊工業新聞、毎日新聞、朝日新聞、中日新聞)にも報道され、フラーレン科学の分野だけでなく社会にも大きなインパクトを与える事ができた。その後、その他のフラーレン化合物、酸化物超伝導体関連物質等の様々な物質に、この新しい方法を応用し、多くの研究成果をあげることができた。

  17. データ欠損時の構造精密化

    坂田 誠, 高田 昌樹

    1995年 ~ 1995年

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    ミリ秒オーダーでタンパク質の動的結晶構造を明らかにする場合、時分割測定したラウエ法に頼らざる得ない。その場合、程度の差はあるもののデータ欠損の問題を避けることが出来ない。このような場合、最良のデータ解析法として、近年急速に発達しているマキシマムエントロピー法MEMが考えられる。さらに、静的な結晶構造が分かっている場合あるいは、ほぼ推測される場合には、MEMにおける初期分布として、原子レベルでの静的結晶構造の知識を活用することが可能と思われる。本研究では、この可能性を実証的に検討し、その有効性を証明することに成功した。具体的には、MEMにおいて通常用いられている初期分布である均一な電子分布の代わりに、静的結晶構造を反映した電子密度分布を用いることにより、データ欠損の問題がほぼ解決出来ることを示した。静的結晶構造が正確なほどデータ欠損の影響を小さくすることが出来、タンパク質の動的構造を解明する上でも静的構造を明らかにしておくことが必要不可欠であることが分かった。この方法を採用することによりデータ欠損率を高めることが可能であることも分かった。最大のデータ欠損率を50%程度にすることも可能であり、実用上、本研究で開発した方法は非常に有効なものと思われる。その他、欠損データから、電子レベルでの結晶構造、すなわち、電子密度分布を正確に求める方法についての研究も行った。

  18. 回折データのイメージングによる固体内イオンの移動機構解明

    坂田 誠, 高田 昌樹

    1995年 ~ 1995年

    詳細を見る 詳細を閉じる

    本研究では、固体イオニクス関連物質の構造をマキシマムエントロピー法MEMにより明らかにした。具体的には、パイロクロア型構造を持つ、Y_2Sn_2O_7、ペロブスカイト型酸化物の基本物質であるSrTiO_3及び、ペロブスカイト型酸化物固溶体で代表的なプロトン伝導体として知られるSrCe_<0,95>Yb_<0,05>O_<3-α>である。実験は主に、実験室系のX線回折装置により行った。粉末試料の粒度分布の回折強度への影響を避けるために試料回転台を用いて測定し、また測定強度の統計性をできるだけ高めるため通常の粉末回折実験よりも長時間の測定を行った。得られた回折パターンは、プロファイルフィッテング法及び、我々が最近開発したMEMのためのリ-トベルト法により各反射についての結晶構造因子の測定値を求め、MEMの入力データとした。MEMの解析はコンピュータープログラムMEEDを用いて行った。得られた主な結果はSrTiO_3において、Ti-O間には強い共有結合が認められる。Ti原子と酸素原子との間の共有結合性が非常に高く、その結合によりソリッドなTiO_6八面体が形成されていることが分かった。一方,SrCe_<0,95>Yb_<0,05>O_<3-α>においては、酸素はどの金属原子とも共同結合性を示さず、酸素の電子密度が著しく歪んでおり、酸素間にCe,Ybを介したつながりが見られた。この様に、プロトン移動経路を示唆する酸素のネットワークが観測された。

  19. 金属フラーレンの構造と物性

    篠原 久典, 高田 昌樹, 百瀬 孝昌, 加藤 立久, 神野 清勝, 斎藤 弥八

    1993年 ~ 1995年

    詳細を見る 詳細を閉じる

    過去3年、われわれは、種々の金属原子を内包したフラーレン(金属内包フラーレン:Endohedral Metallofullerenes)あるいは、金属を内包したナノカプセル(Carbon Nanocapsules)の生成、分離・単離、構造、電子状態、物性および反応の解明に重点を置いてきた。このため現在では、金属内包フラーレンに関する重要なpublicationのほとんどは、わが国の研究グループからのものである、といわれる程になつた。以下に、本重点領域研究期間の過去3年の間に得られた、わが班員の金属内包フラーレンに関する主な業績、特に、“priority level"(i.e.,"先取権争いに勝利した")の業績のみを紹介する: (1)多くの新しい金属内包フラーレンの生成:良く知られている、La,Y,Sc(3価)原子以外にも、Gd,Pr,Ceなどのランタノイド原子のほか、Ca(2価)やTi(4価)の金属を内包したフラーレンの生成に成功した。 (2)多くの金属内包フラーレンの、初めての分離と単離:(1)で生成した種々の金属フラーレンの単離を、2段階HPLC法で"純品化"することに成功。金属内包フラーレンの分離・精製法を確立した。 (3)金属内包フラーレンの構造異性体の発見と単離:ほとんどの金属内包フラーレンには、構造異性体があることを発見し、またこれらを精製・単離した。 (4)金属内包フラーレンの構造解析:シンクロトロンX線回折、STM(走査トンネル顕微鏡),^<13>C-NMR,^<45>Sc-NMR,HREM(高分解能電子線回折)などの手段による、初めての構造解析(分子構造と結晶構造)。. (5)金属内包フラーレンの電子構造の解明:UPS/XPS(紫外・X線電子分光),ESR,IR/Raman分光,レーザー分光、などの手段による特異な電子構造の解明。 以上のように、新規物質である金属内包フラーレンの精製、分離・単離から構造解析や電子状態の解明まで、すべてわが重点班の研究者によって行われた。多くの研究が、Nature,Phys.Rev.Lett.J.Am.Chem.Soc.などのインパクトパラメターの非常に高い雑誌の速報として発表された。そして、これらすべてが、“priority level"の研究であることを特記したい。

  20. データ欠損時の電子密度分布

    坂田 誠, 高田 昌樹

    1994年 ~ 1994年

    詳細を見る 詳細を閉じる

    放射光より蛋白質の結晶構造をミリ秒オーダーで解析する場合、時分割ラウエ法により行うことが最も現実的である。この様な解析において、非常に大きな問題はミリ秒オーダーでデータを収集するために、ラウエパターンとラウエパターンの間に、逆空間上で測定されない領域が出来てしまうことである。この様にデータが欠損した状態で通常のフーリエ合成を行うと、得られる電子密度分布は欠損したデータの影響をそのまま受けて、大変不十分な電子密度分布しか得られない。この問題を解決するために、欠損したデータを用いてマキシマム・エントロピー法により電子密度を求める方法を確立した。マキシマム・エントロピー法は情報理論から発達した解析法で、これまで精密結晶構造解析に適用され、電子レベルの構造を解明する上で、絶大な威力を発揮してきた。本研究は、マキシマム・エントロピー法によりデータ欠損時における原子レベルの構造解析を可能にすることを目的としている。本研究の結果、データ欠損率が50%の時には、全く問題なしに、原子レベルの構造が得られることがわかった。さらに驚くべきことに、70%の欠損時においても、結晶の基本構造を確認出来ることが判明した。一方、これまで用いられてきたフーリエ合成法では、欠損率50%の時には、原子位置以外の多くの場所にフーリエ級数打ち切り効果による偽のピークが生じ、結晶構造の確認が著しく困難になった。また、欠損率70%の時には、結晶構造を全く再現しないことがわかった。それ故、本方法はミリ秒オーダーの蛋白質のダイオミックスを解明するためには、必須の解析法であると結論した。

  21. マキシマムエントロピー法によるDy系およびY系の電子密度

    坂田 誠, 高田 昌樹

    1993年 ~ 1993年

    詳細を見る 詳細を閉じる

    高温超伝導体の構造に関しては、これまで非常に多くの報告がなされている。回折法に限定しても、中性子回折あるいはX線回折データによりリートヴェルト法、最小自乗法、フーリエ法により数多くの解析例が知られている。それにより、高温超伝導体の基本構造は既に確立している。しかしながら、これらの方法では結合状態など基本構造以上の詳細な構造情報を得ることが非常に難しい。最近、新たな解析方法として、マキシマムエントロピー法が提唱されている。この方法によれば、X線回折データからは結合状態を含めた電子密度分布が、中性子回析データからは、格子振動の平均像としての核密度分布が得られる。単純化した表現をするならば、X線からは電子系、中性子からはフォノン系の情報が平均像としてではあるが、得られることになる。この方法をYBCOに適用し、296Kおよび15Kでの核密度分布を求めた。核密度分布をさらに解析し、一体近似の範囲内で、非調和性を含むポテンシャルを求めることが可能である。現在、この様な解析を行っているが、核密度分布から理解できる定性的な結果を述べると、Ba、O_2、O_3に対してc軸方向に非対称な非調和性が認められる。また、O_4は最も大きな熱振動を示し、Cu-O面内に著しい異方性が認められる。電子密度分布に関しては、放射光により高分解なX線データが収集されており、解析を始めた段階である。

  22. 粉末回折法の新展開

    坂田 誠, 浅野 肇, 山中 高光, 虎谷 秀穂, 高田 昌樹, 原田 仁平

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Co-operative Research (A)

    研究種目:Grant-in-Aid for Co-operative Research (A)

    研究機関:Nagoya University

    1991年 ~ 1992年

    詳細を見る 詳細を閉じる

    本研究は、近代的な粉末回折法の非常に大きな可能性を、さらに発展させることを目的として行なわれた。粉末回折法は非常に古い手法であるが、リートヴェルト法の出現あるいは、パターン分解法の発展などにより、以前には考えられない程の能力を発揮している。その勢いは、マキシマム・エントロピー法による粉末データの解析,放射光による高分解能粉末X線法の確立などにより、さらに加速している。その様な状況下で行った、本総合研究の成果は、数多くのものがある。そのいくつかを述べることにする。マキシマム・エントロピー法による解析では、同一物質な対して、X線粉末回折データより電子密度分布が、中性子粉末回折データからは、原子核密度分布が求められた。その物質とは、ルチルデ、電子密度分布には、チタンと酸素間に存在する共有結合を示に結合電子が観測されている。一方の、原子核密度では、原子間には全くと言って良い程原子核密度が存在しない。原子サイト周辺の核密度は、熱振動による原子核密度の広がりを表している。ルチルの場合、チタンと酸素では、この様子が非常に異っている。チタンは、ほゞ等方的であるのに対して、酸素は、三角形上の分布をして居り、Skewnessを示すことが判明した。この効果は、酸素原子の分極に影響を与えるはずで、非常に注目される。酸化物高温超伝導体のリートヴェルト法による解析は非常に数多くなされた。常圧だけの解析だけではなく高圧下における構造変化も研究され、粉末回折法の有用性を疑いないものとした。放射光による実験は、種々試みられた。その中でも放射光とイメージシグプレーとを組み合せた実験は、有機物の構造解析や軽之素からなる系の電子レベルでの構造解析に大変威力を発揮した。その他、中性子粉末回折実験による強磁性体の構造解析、化合物半導体ガリウムヒ素の温度因子など、多方面に亘る成果が得られた。

  23. マキシマム・エントロピー法による固体中水素の電子密度分布

    坂田 誠, 高田 昌樹, 原田 仁平

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for General Scientific Research (B)

    研究種目:Grant-in-Aid for General Scientific Research (B)

    研究機関:Nagoya University

    1990年 ~ 1992年

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    本研究の目的は,マキシマムエントロピー法と言う新しい方法により,固体中の水素の電子密度分布を調べることにあった。そのために,マキシマロエントロピー法が,この様な目的に有用であることを証明することから研究を開始する必要があった。それには,本研究の補助金で購入した水素検出用X線回折装置が,大いに威力を発揮した。安定度が高く,高分解能なデータが比較的簡単に測定出来るため,多くの物質に対して実験データを収集することが出来,マキシマムエントロピー法の有用性を実験的に実証することが出来た。この装置なくしては,本研究の遂行は,ほとんど不可能であった。これらの努力により研究代表者は,平成4年度日本結晶学会賞を授与された。この事は,学会もこの新しい方法に大いに注目していることを意味している。固体中水素の電子密度分布に関しても,非常に興味のある知見が得られた。固体中水素の電子密度分布は水素結合をしている時とイオン結合をしている時とでは,大いに異なることが判明した。水素結合をしている時は,共有結合電子の様な振舞を示し,自由原子による近似は非常に不適当であることがわかった。しはしば,X線では最も軽い元素である水素を検出できないと,教科書でも書かれる場合があるが,これは誤解で,自由原子による近似が成り立たないため,マキマムエントロピー法の様な結晶構造モデルに依存しない解析法が必となるだけである。一方,イオン結合の状態では,水素は非常に球対称な電子密度分布を示す。この時は,一見自由原子モデルで記述出来る様に思われるかも知れないが,負のイオンとなっているため,やはり,自由原子モデルは適当ではない。本研究により,近代的なX線回折法により,固体中水素の電子密度分布を詳細に調べることが出来ることが判明した。しかし,その目的には,マキシマムエントロピー法を用いることが必要不可欠となることに留意する必要がある。

  24. 超イオン伝導体のマキシマム・エントロピー法による電子密度分布の研究

    高田 昌樹

    1990年 ~ 1990年

︎全件表示 ︎最初の5件までを表示

社会貢献活動 15

  1. 地域と世界をつなぐ、NanoTerasuナノテラス

    放射光利活用による地域企業の課題解決・価値創造フォーラム~放射光で観えると変わるものづくりの未来~

    2024年3月13日 ~ 2024年3月13日

  2. 君たちが世界の主役となる舞台です!Nano Terasu(ナノテラス)

    宮城県仙台第一高等学校令和5年度第2学年先端科学技術講演会

    2024年1月9日 ~ 2024年1月9日

  3. 地方から世界へ NanoTerasuの 地域イノベーション 戦略的活用について

    2023年度イノベーションを牽引する創造型企業の経営幹部による朝食交流会

    2023年11月10日 ~ 2023年11月10日

  4. ナノテラスの現状と、これから -Nice-to-haveではなく、Must-haveの施設とするために-

    宮城県経営者協会常任幹事会

    2023年11月9日 ~ 2023年11月9日

  5. NanoTerasuの脱炭素社会実現への取り組み

    CLOMA技術部会主催意見交換会

    2023年7月24日 ~ 2023年7月24日

  6. 「モノづくりからコトづくりへ NanoTerasu(ナノテラス)が変える地域産業」

    令和5年福島産業人クラブ記念講演会

    2023年7月18日 ~ 2023年7月18日

  7. 東北よりイノベーションを変える NanoTerasu (ナノテラス)

    宮城中小企業研究会ナノテラス見学会

    2023年7月4日 ~ 2023年7月4日

  8. 次世代放射光施設NanoTerasu(ナノテラス) の概要 ⼯業⼈材の活躍・育成の新たな場としての視座から

    令和 5 年度宮城県高等学校工業教育研究会研修会

    2023年5月12日 ~ 2023年5月12日

  9. 放射光で広がる未来のモノづくり~世界から選ばれる「光イノベーション都市・仙台」~

    仙台市主催「G7仙台科学技術大臣会合」開催記念セミナー

    2023年5月9日 ~ 2023年5月9日

  10. ミッションイノベーション 次世代放射光ナノテラスと東北大学サイエンスパークの挑戦

    地方銀行協会・木曜会講演

    2023年4月20日 ~ 2023年4月20日

  11. 「地域企業のイノベーション戦略を支援するナノ テラス -小さな世界企業を生み出すために‐」

    「放射光でデザインする、ものづくり企業の未来 ~放射光利活用 による地域企業の課題解決・価値創造セミナー~」

    2023年3月3日 ~ 2023年3月3日

  12. 君たちが主役となる舞台です!NanoTerasu(ナノテラス)

    第3回先端科学講演会

    2023年1月24日 ~ 2023年1月24日

  13. 「イノベーションのエンジンとしてのナノテラス」

    放射光で広がる未来のモノづくり ~『共創』で輝く「光イノベーション都市・仙台」~

    2022年11月22日 ~ 2022年11月22日

  14. 仙台・次世代放射光施設だからこそできること

    放射光で広がる未来のモノづくり~「光イノベーション都市・仙台」の可能性~ 株式会社 矢野経済研究所

    2021年11月18日 ~ 2021年11月18日

    詳細を見る 詳細を閉じる

    仙台市は、市内に整備が進む2024年度に運用開始予定の次世代放射光施設への興味・関心がある企業人向けに、当該施設の概要及び活用方法等を紹介するウェビナーを開催します。

  15. 次世代放射光施設について

    オンラインピッチイベント SuMi TRUST Innovation Pitch @ TOHOKU University

    2021年10月15日 ~ 2021年10月15日

︎全件表示 ︎最初の5件までを表示

メディア報道 14

  1. NanoTerasuが照らす新たな光!

    仙台商工会議所 仙台商工会議所月報「飛翔」 2024年3月号 P2~3

    2024年3月

    メディア報道種別: 新聞・雑誌

  2. 「日本を変える」経済効果は1兆9000億円!世界最先端「ナノテラス」への期待

    仙台放送 「仙台放送Live News イット!」

    2024年1月19日

    メディア報道種別: テレビ・ラジオ番組

  3. 新春インタビュー「今年にかける」

    NHK仙台局 「てれまさ」 https://www.nhk.jp/p/ts/M917RJ4V72/episode/te/577MMV9R8G/

    2024年1月11日

    メディア報道種別: テレビ・ラジオ番組

  4. ナノの世界照らす巨大顕微鏡

    日刊建設工業新聞社 日刊 建設工業新聞 9面

    2024年1月11日

    メディア報道種別: 新聞・雑誌

  5. NanoTerasuという未来

    一般社団法人 日本電気協会新聞部 エネルギー専門新聞「電気新聞」 1/22,2/5,2/19,2/26

    2024年1月

    メディア報道種別: 新聞・雑誌

  6. “長続き”を可能にする~経営の知恵と工夫~

    BSTV東京 小谷真生子の地球大調査~SDGs・ESGが変えるミライ~ https://txbiz.tv-tokyo.co.jp/sdgs/vod/post_288126

    2023年12月24日

    メディア報道種別: テレビ・ラジオ番組

  7. 需要増すプラスチックなどの再生材、「ナノテラス」で診断・DB化へ…東北大

    読売新聞東北総局 読売新聞 https://www.yomiuri.co.jp/science/20231008-OYT1T50212/

    2023年10月17日

    メディア報道種別: 新聞・雑誌

  8. 世界をリードする超最先端施設

    日本テレビ カズレーザーと学ぶ。 https://www.ntv.co.jp/kazu/articles/3115wgi9ptpfs664182p.html

    2023年9月26日

    メディア報道種別: テレビ・ラジオ番組

  9. 産学官の連携に評価

    読売新聞東北総局 読売新聞 2023年9月2日22面

    2023年9月2日

    メディア報道種別: 新聞・雑誌

  10. 特集 ナノテラス

    J:COM仙台チャンネル LIVEニュース

    2023年8月12日

    メディア報道種別: テレビ・ラジオ番組

  11. G7仙台科学技術大臣会合を、私たちはどう活かすか 仙台開催の意義と舞台裏

    プレスアート Kappo 仙台闊歩 2023年9月号 060

    2023年8月4日

    メディア報道種別: 新聞・雑誌

  12. 日本の未来を照らす世界最先端の技術

    テレビ朝日 「サンデーLIVE!!」松岡修造のみんながん晴れ https://www.youtube.com/watch?v=IGUI_DorMIM

    2023年7月30日

    メディア報道種別: テレビ・ラジオ番組

  13. 東北の地に生まれる、「ナノテラス」とは?

    株式会社CCメディアハウス pen+ p46~51

    2023年2月24日

    メディア報道種別: 新聞・雑誌

  14. 次世代放射光施設では、原子や分子の大きさのナノの世界をくっきり見ることができ、それは文字通り人類の未来を明るく照らす光となると思います 執筆者本人

    今野印刷株 仙台っ子 ザ・インタビュー P16-P17

    2021年11月

    メディア報道種別: その他

︎全件表示 ︎最初の5件までを表示

学術貢献活動 3

  1. NanoTerasuにおける産業利用拡大に関する取組とSPring-8の高度化への期待

    2023年6月29日 ~ 2023年6月29日

    学術貢献活動種別: その他

  2. 実践データ駆動科学オンラインセミナー 次世代放射光による先端可視化技術とAIの協奏 マテリアル・デザインの社会実装を目指して

    2021年8月23日 ~ 2021年8月23日

    学術貢献活動種別: 大会・シンポジウム等

  3. 第3回 次世代放射光 国際フォーラム

    2021年7月1日 ~ 2021年7月1日

    学術貢献活動種別: 大会・シンポジウム等