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Takahisa Omata

Section

Institute of Multidisciplinary Research for Advanced Materials

Job title

Professor

Degree

博士（工学）（東京工業大学）
工学修士（横浜国立大学）

researchmap

https://researchmap.jp/7000022452

J-GLOBAL ID

201801000638616180

Research Interests 5

燃料電池
プロトン－電子混合伝導体
太陽電池光吸収層
プロトン伝導体
新材料設計

Research Areas 1

Nanotechnology/Materials / Inorganic materials /

Awards 8

The 2017 Richard and Patricia Spriggs Phase Equilibria Award

2017/10/09　アメリカセラミックス協会　High temperature phases with wurtzite-derived structure in Zn2LiGaO4?ZnO alloy system
PCCP Poster Presentation Award for the poster contribution in the 21st International Conference on Solid State Ionics

2017/06/23　Proton transport property of phosphate glass fabricated via alkali-proton substitution
第42回論文賞

2017/03/28　一般社団法人資源・素材学会　高品位マットからのNi, Co濃縮相の抽出分離
大阪大学総長顕彰研究部門

2015/07　大阪大学　コロイダル量子ドットの合成と素子化
学術賞

2014/06　日本セラミックス協会　酸化物・カルコゲナイド系コロイダルナノ結晶の合成と機能開拓
Excellent Paper Award

2008/06　2008 MRS International Materials Research Conference, Organizing Committee　Syntehsis of CuInS2 Nanocrystals and Their Structural Transformation Triggered by the Ligand Exchange
日本セラミックス協会学術論文誌1998優秀論文賞

1999/05　日本セラミックス協会　Observation of electronic structure in conduction band of CaTiO3
進歩賞

1999/05　日本セラミックス協会　透明酸化物および遷移金属酸化物の電子伝導性と電子構造に関する研究

Show all ︎Show 5

Papers 188

Role of hydrogen in the n-type oxide semiconductor MgIn2O4: Experimental observation of electrical conductivity and first-principles insight

Saki Kudo, Tomoyuki Yamasaki, Issei Suzuki, Arunkumar Dorai, Rafael Costa-Amaral, Soungmin Bae, Yu Kumagai, Hiroshi Tanimura, Tetsu Ichitsubo, Takahisa Omata

APL Materials　13　(4)　2025/04/01
Publisher: AIP Publishing
DOI： 10.1063/5.0253161 　

eISSN： 2166-532X

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Hydrogen impurities significantly influence the electrical conductivity of oxide semiconductors such as MgIn2O4, widely used in devices such as thin-film transistors. However, their role and chemical environment have not been fully clarified. This study investigated the conductivity of MgIn2O4 at elevated temperatures under air and H2 atmospheres, revealing higher and reversible conductivity in H2 due to hydrogen dissolution. Hall measurements, thermal desorption spectrometry, and nuclear magnetic resonance spectroscopy revealed that hydrogen dissolves in MgIn2O4, ionizing to produce electrons and interstitial protons. Density functional theory calculations indicate that hydrogen stabilizes near vacant octahedral cation sites, forming O–H bonds and shallow donor levels. Indium atoms at magnesium sites lead to shallow donor levels, whereas oxygen vacancies form deep levels. The results identify interstitial hydrogen and indium atoms at magnesium sites, rather than oxygen vacancies, as key donors under H2-rich or low oxygen conditions, providing insights for controlling the conductivity of MgIn2O4 in devices.
Non-stoichiometry in SnS: How it affects thin-film morphology and electrical properties

Taichi Nogami, Issei Suzuki, Daiki Motai, Hiroshi Tanimura, Tetsu Ichitsubo, Takahisa Omata

APL Materials　2025/03/01

DOI： 10.1063/5.0248310 　
Unconventional and Powerful Ion Sources for Solid-State Ion Exchange, Cu₂SO₄ and Cu₃PO₄: Exemplified by the Synthesis of Metastable β-CuGaO₂ from Stable β-LiGaO₂ International-journal Peer-reviewed

Issei Suzuki, Kako Washizu, Daiki Motai, Masao Kita, Takahisa Omata

Inorganic Chemistry　64　(5)　2165-2169　2025/01/27
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.inorgchem.4c05078 　

ISSN： 0020-1669

eISSN： 1520-510X
Effects of Process Gas Pressure on Properties of WO₃ Thin Films Deposited by RF Sputtering Peer-reviewed

Rantaro Matsuo, Tomoyuki Yamasaki, Issei Suzuki, Sakiko Kawanishi, Takahisa Omata

The Journal of Physical Chemistry C　129　(2)　1516-1524　2025/01/16
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.jpcc.4c07254 　

ISSN： 1932-7447

eISSN： 1932-7455
Enhancing Proton Mobility in Silicophosphoric Acid by Replacing Si with Al Peer-reviewed

Tomohiro Ishiyama, Yuya Yamada, Hiroki Nagashima, Issei Suzuki, Masaya Fujioka, Madoka Ono, Takahisa Omata, Junji Nishii

Inorganic Chemistry　64　105-112　2025/01/14
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.inorgchem.4c04250 　

ISSN： 0020-1669

eISSN： 1520-510X
Design of low-lattice-mismatch type-I heterostructures of zinc chalcogenide and synthesis of ZnTeS quantum dots as key materials for realizing green and red emission International-journal Peer-reviewed

Rantaro Matsuo, Masao Kita, Satoshi Tsukuda, Takahisa Omata

Journal of Materials Chemistry C　13　(8)　3825-3835　2025
Publisher: Royal Society of Chemistry (RSC)
DOI： 10.1039/d4tc04696j 　

ISSN： 2050-7526

eISSN： 2050-7534

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Green- and red-emissive type-I nano-heterostructures with a small lattice mismatch at the interfaces were designed based on calculations of the band alignment in ZnTeS alloys, which exhibit large band gap bowing.
Replacing Sodium Ions with Protons in Vanadophosphate Glass: Suppression of Electronic Conduction by Local Structural Change around Vanadium Ions International-journal International-coauthorship Peer-reviewed

Aman Sharma, Issei Suzuki, Kei Toyooka, Tomohiro Ishiyama, Junji Nishii, Takahisa Omata

The Journal of Physical Chemistry C　128　(23)　9793-9801　2024/06/04
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.jpcc.4c02589 　

ISSN： 1932-7447

eISSN： 1932-7455
Designing Topotactic Ion-Exchange Reactions in Solid-State Oxides Through First-Principles Calculations Peer-reviewed

Issei Suzuki, Masao Kita, Takahisa Omata

Chemistry of Materials　128　9793-9801　2024/04/17

DOI： 10.1021/acs.chemmater.3c03016 　
n型酸化物半導体MgIn2O4の電気伝導性の雰囲気依存性その起源 Invited Peer-reviewed

工藤咲季, 鈴木一誓, 山﨑智之, 谷村洋, 市坪哲, 小俣孝久

燃料電池　23　66-72　2024/04
Low-temperature growth of BaZrO3 and Ba(Zr,Y)O3–δ thin films via spray pyrolysis deposition International-journal International-coauthorship Peer-reviewed

Issei Suzuki, Hiromasa Tawarayama, Masatoshi Majima, Takahisa Omata

Thin Solid Films　140249-140249　2024/02
Publisher: Elsevier BV
DOI： 10.1016/j.tsf.2024.140249 　

ISSN： 0040-6090
High proton conductivity and thermal stability at intermediate temperatures of phosphate glasses and their melts containing rare-earth oxides achieved by high thermal stability of proton carriers International-coauthorship Peer-reviewed

Takashi Tatebayashi, Tomohiro Ishiyama, Takuya Kinoshita, Tong Fang, Yang Ren, Khurelbaatar Zagarzusem, Masaya Fujioka, Gaoyang Zhao, Meng Liu, Takahisa Omata, Junji Nishii

Solid State Ionics　403　116413-116413　2023/12
Publisher: Elsevier BV
DOI： 10.1016/j.ssi.2023.116413 　

ISSN： 0167-2738
Ambient Aqueous-Phase Synthesis of Highly Stable Methylammonium Tin Iodide Perovskites Using Alkali Iodides and Ascorbic Acid International-journal Peer-reviewed

Koji Yokoyama, Takahisa Omata, Shun Yokoyama, Hideyuki Takahashi

ACS Applied Energy Materials　6　(21)　11070-11080　2023/10/30
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acsaem.3c01909 　

ISSN： 2574-0962

eISSN： 2574-0962
Alkali Mono-Pnictides: A New Class of Photovoltaic Materials by Element Mutation International-journal International-coauthorship Peer-reviewed

Yu Kumagai, Seán R. Kavanagh, Issei Suzuki, Takahisa Omata, Aron Walsh, David O. Scanlon, Haruhiko Morito

PRX Energy　2　(4)　2023/10/03
Publisher: American Physical Society (APS)
DOI： 10.1103/prxenergy.2.043002 　

eISSN： 2768-5608
Site-Dependent Luminescence from Pr³⁺ in Double-Perovskite-Type Alkaline Earth Lanthanum Tantalates International-journal Peer-reviewed

Kazushige Ueda, Ayumu Oya, Shoichiro Nagashima, Tatsuhiko Ogata, Tetsuo Honma, Takahisa Omata

The Journal of Physical Chemistry C　127　(18)　8833-8839　2023/04/27
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.jpcc.3c01208 　

ISSN： 1932-7447

eISSN： 1932-7455
High open-circuit voltage in single-crystalline n-type SnS/MoO₃ photovoltaics International-coauthorship Peer-reviewed

Issei Suzuki, Zexin Lin, Taichi Nogami, Sakiko Kawanishi, Binxiang Huang, Andreas Klein, Takahisa Omata

APL Materials　11　(3)　031116-031116　2023/03/01
Publisher: AIP Publishing
DOI： 10.1063/5.0143617 　

eISSN： 2166-532X

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It has been recently reported that n-type single crystalline SnS exhibits a large band bending (∼1 eV) at the interface with MoO₃, which is a large work function material. In this study, we applied this interface to solar cells for the first time and evaluated its photovoltaic properties. The highest V_OC achieved was 437 mV. Although this value is the highest ever recorded for SnS solar cells, it was lower than the expected value of 700–800 mV. The highest power conversion efficiency ( PCE) was 4.4%. Based on an analysis of the device parameters, we propose methods for improving the device performance, including V_OC, the short-circuit current, and PCE. The carrier-collection length of the n-type SnS single crystals was estimated to be ∼200 nm based on the external quantum efficiency measurements. Therefore, this study demonstrates that the V_OC of SnS solar cells can be improved by fabricating a junction with MoO₃ thin films.
Pulsed laser deposition of β-NaGaO₂: significant dependence of sodium fraction, morphology, and phases of the film on deposition position in the plume Peer-reviewed

Shunichi Suzuki, Issei Suzuki, Takahisa Omata

Japanese Journal of Applied Physics　2023/02/14
Publisher: IOP Publishing
DOI： 10.35848/1347-4065/acbbff 　

ISSN： 0021-4922

eISSN： 1347-4065

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Abstract Thin films of β-NaGaO₂, a precursor material of β-CuGaO₂, were fabricated using pulsed laser deposition. The phase and morphology of these films depended on the deposition position, i.e., the target-substrate distance and distance from the central plume axis. Three phases appeared in the films, namely a Na-deficient and stoichiometric β-NaGaO₂, amorphous with a Na fraction with total cations, x_Na, of ~0.375, and unidentified phase with x_Na of ~0.57. These three phases formed four characteristic textures. The variation in phase and morphology is discussed and explained in terms of the spatial distribution of the Na fraction and kinetic energy of ablated particles deposited on the substrate. By using the obtained stoichiometric β-NaGaO₂ film, a stoichiometric β-CuGaO₂ film was successfully fabricated. Its energy band gap was determined to be 1.64 eV, which is approximately 0.1 eV larger than that previously reported for Cu-deficient β-Cu_0.9GaO_2-δ.
Experimental Identification of Atomic Orbital Contributions to SnS Valence Band using Polarization‐Dependent Angle‐Resolved Photoemission Spectroscopy International-journal Peer-reviewed

Issei Suzuki, Sakiko Kawanishi, Kiyohisa Tanaka, Takahisa Omata, Shin-ichiro Tanaka

physica status solidi (b)　2200408-2200408　2023/02/08
Publisher: Wiley
DOI： 10.1002/pssb.202200408 　

ISSN： 0370-1972

eISSN： 1521-3951
Enhancing proton mobility and thermal stability in phosphate glasses with WO₃: the mixed glass former effect in proton conducting glasses International-journal International-coauthorship

Aman Sharma, Issei Suzuki, Tomohiro Ishiyama, Takahisa Omata

Physical Chemistry Chemical Physics　25　(28)　18766-18774　2023
Publisher: Royal Society of Chemistry (RSC)
DOI： 10.1039/d3cp01453c 　

ISSN： 1463-9076

eISSN： 1463-9084

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The replacement of PO_5/2 with WO₃ increased both proton mobility and thermal stability of proton conducting phosphate glass. The P–O–W linkages enhance the inter-phosphate chain proton migration and suppress viscous flow at elevated temperature.
Avoiding Fermi Level Pinning at the SnS Interface for High Open-Circuit Voltage International-journal International-coauthorship Peer-reviewed

Issei Suzuki, Binxiang Huang, Sakiko Kawanishi, Takahisa Omata, Andreas Klein

The Journal of Physical Chemistry C　126　(48)　20570-20576　2022/12/08
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.jpcc.2c04212 　

ISSN： 1932-7447

eISSN： 1932-7455
Electronic structure of SnS valence band International-journal Peer-reviewed

Issei Suzuki, Sakiko Kawanishi, Kiyohisa Tanaka, Takahisa Omata, Shin-ichiro Tanaka

2022/08/29

DOI： 10.6084/m9.figshare.20526840 　

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"Thumnail.png" shows the screenshot of Figures 1 and 2. "Figure1.pxp" shows the E-k plot of SnS valence band in the Γ-Z direction with continuously varied k_z. This figure was made by igor Pro 9 and is accessble only by igor. Figure 2 shows the CEC plot of SnS valence band of each atomic orbital. With this figure, you can change the layer number which corresponds to the binding energy. This figure was made by igor Pro 9 software and is accessble only by igor.
Current status of n-Type SnS: Paving the way for SnS homojunction solar cells International-journal Peer-reviewed

Issei Suzuki, Sakiko Kawanishi, Takahisa Omata, Hiroshi Yanagi

Journal of Physics: Energy　4　(4)　042002-042002　2022/08/03
Publisher: IOP Publishing
DOI： 10.1088/2515-7655/ac86a1 　

eISSN： 2515-7655

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Abstract Orthorhombic SnS is a promising thin-film solar-cell material composed of safe and abundant elements with suitable optical properties for photovoltaic application. For approximately two decades, SnS solar cells have employed heterojunction structures with p-type SnS and other n-type semiconductors because undoped SnS typically exhibits p-type electrical conduction. However, their conversion efficiency has remained stagnant at 4–5% for a long time. A breakthrough is required to significantly improve their conversion efficiencies before SnS solar cells can be put into practical use. Therefore, this comprehensive review article establishes the current state of the art in SnS solar cells, with an aim to accelerate both fundamental research and practical applications in this field. We discuss issues specific to SnS heterojunction solar cells, the advantages of the homojunction structure, and summarize recent advances in the n-type conversion of SnS by impurity doping, which is required to form a homojunction. The latter half of this article describes the latest research on the fabrication of n-type single crystals and films of halogen-doped n-type SnS, which is prepared via a doping system suitable for practical use. We conclude the article by summarizing the current status and future work on SnS homojunction devices, including the development of high-efficiency multi-junction SnS solar cells by band gap engineering.
Visualization of polysulfide dissolution in lithium-sulfur batteries using in-situ NMR microimaging International-journal International-coauthorship Peer-reviewed

Arunkumar Dorai, Junichi Kawamura, Takahisa Omata

Electrochemistry Communications　141　107360-107360　2022/08
Publisher: Elsevier BV
DOI： 10.1016/j.elecom.2022.107360 　

ISSN： 1388-2481
Contribution of the Sn 5s state to the SnS valence band: direct observation via ARPES measurements International-journal Peer-reviewed

Issei Suzuki, Sakiko Kawanishi, Kiyohisa Tanaka, Takahisa Omata, Shin-ichiro Tanaka

Electronic Structure　4　(2)　025004-025004　2022/06/01
Publisher: IOP Publishing
DOI： 10.1088/2516-1075/ac6ea8 　

eISSN： 2516-1075

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Abstract Tin sulfide (SnS) is a compound semiconductor that has been studied for a wide range of applications, including solar cells and thermoelectric materials. In this study, the electronic structure of the SnS valence band, which is important for such applications, was investigated via angle-resolved photoelectron spectroscopy with two different excitation energies in the extreme ultraviolet region (21 and 60 eV). The contribution of the Sn 5s state to the SnS valence band was determined in relation to the k-vector by utilizing the fact that the cross section of Sn 5s state varies significantly compared to those of other states in the extreme ultraviolet region. The experimental results demonstrate that the Sn 5s state significantly contributed to the k-vector around the valence band maximum (VBM) and second VBM (VBM1).
Site-Dependent Tb³⁺ Luminescence by Energy Transfer from Ce³⁺ in Ce³⁺–Tb³⁺ Codoped LaLuO₃ International-journal Peer-reviewed

Shoichiro Nagashima, Kazushige Ueda, Takahisa Omata

The Journal of Physical Chemistry C　126　(14)　6499-6504　2022/04/05
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.jpcc.2c01074 　

ISSN： 1932-7447

eISSN： 1932-7455
Growth of β-NaGaO2 thin films using ultrasonic spray pyrolysis International-journal Peer-reviewed

Issei Suzuki, Shunichi Suzuki, Tatsuya Watanabe, Masao Kita, Takahisa Omata

Journal of Asian Ceramic Societies　2022/04/03

DOI： 10.1080/21870764.2022.2082049 　
Origin of the Temperature Dependence of Proton Conductivity in Phosphate Glass Prepared by Alkali-Proton Substitution Technique International-journal Peer-reviewed

Tomohiro Ishiyama, Takuya Yamaguchi, Junji Nishii, Toshiharu Yamashita, Hiroshi Kawazoe, Takahisa Omata

Journal of The Electrochemical Society　169　(3)　034517-034517　2022/03/01
Publisher: The Electrochemical Society
DOI： 10.1149/1945-7111/ac5793 　

ISSN： 0013-4651

eISSN： 1945-7111

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The temperature dependence of proton conductivity in 36HO_1/2−4NbO_5/2−2BaO-4LaO_3/2−4GeO₂−1BO_3/2−49PO_5/2 glasses prepared through the alkali-proton substitution method was investigated in this study. The activation energy of proton conduction, E_a, was found to exhibit an non-Arrhenius type temperature dependence. The origin of the temperature dependence of the proton conductivity caused by thermal expansion of the glass structure was discussed in terms of the effect of changes in the local environment surrounding the protons. These changes were elucidated using Raman spectroscopy, ¹H- and ³¹P-NMR, infrared spectroscopy, and molecular modeling. Because protons form O-H bonds, they are sensitive to changes in the distance between two oxygen atoms, which affects the strength of the hydrogen bond, and concluded that there is a temperature dependence as observed.
Anhydrous Silicophosphoric Acid Glass: Thermal Properties and Proton Conductivity International-journal International-coauthorship Peer-reviewed

Takahisa Omata, Aman Sharma, Issei Suzuki, Tomohiro Ishiyama, Shinji Kohara, Koji Ohara, Madoka Ono, Yang Ren, Khurelbaatar Zagarzusem, Masaya Fujioka, Gaoyang Zhao, Junji Nishii

ChemPhysChem　2022/02/04

DOI： 10.1002/cphc.202100840 　

ISSN： 1439-4235

eISSN： 1439-7641
Phase Transformation of Metastable Cu<inf>2</inf>ZnGeO<inf>4</inf> with a Wurtz-Kesterite Structure at Elevated Temperatures International-journal Peer-reviewed

Masao Kita, Issei Suzuki, Noriyuki Wada, Takahisa Omata

Inorganic Chemistry　2022

DOI： 10.1021/acs.inorgchem.2c00480 　

ISSN： 0020-1669

eISSN： 1520-510X
Direct evaluation of hole effective mass of SnS–SnSe solid solutions with ARPES measurement International-journal Peer-reviewed

Issei Suzuki, Zexin Lin, Sakiko Kawanishi, Kiyohisa Tanaka, Yoshitaro Nose, Takahisa Omata, Shin-Ichiro Tanaka

Physical Chemistry Chemical Physics　24　(2)　634-638　2022

DOI： 10.1039/d1cp04553a 　

ISSN： 1463-9076

eISSN： 1463-9084
First Principles Calculation of Electrical and Optical Properties of Cu₃AsO₄: Promising Thin-Film Solar Cell Absorber from Nonferrous Metal Manufacturing By-Products Peer-reviewed

Issei Suzuki, Sakiko Kawanishi, Naoki Ohashi, Aiga Gomi, Junya Kano, Hiroto Watanabe, Satoshi Asano, Takahisa Omata

MATERIALS TRANSACTIONS　63　(1)　73-81　2022/01/01
Publisher: Japan Institute of Metals
DOI： 10.2320/matertrans.m-m2021851 　

ISSN： 1345-9678

eISSN： 1347-5320
Proton-conducting phosphate glass: Recent development as an electrolyte in intermediate temperature fuel cells Peer-reviewed

Tomohiro ISHIYAMA, Takuya YAMAGUCHI, Takahisa OMATA

Journal of the Ceramic Society of Japan　130　(1)　1-9　2022/01/01
Publisher: Ceramic Society of Japan
DOI： 10.2109/jcersj2.21110 　

ISSN： 1882-0743

eISSN： 1348-6535
n-type electrical conduction in SnS thin films International-journal International-coauthorship Peer-reviewed

Issei Suzuki, Sakiko Kawanishi, Sage R. Bauers, Andriy Zakutayev, Zexin Lin, Satoshi Tsukuda, Hiroyuki Shibata, Minseok Kim, Hiroshi Yanagi, Takahisa Omata

Physical Review Materials　5　(12)　2021/12/09
Publisher: American Physical Society (APS)
DOI： 10.1103/physrevmaterials.5.125405 　

eISSN： 2475-9953
Enhanced Valley Splitting of Exciton Emission in Colloidal PbSe Quantum Dots When the Interdot Distance Coincides with Onset of Förster Resonance Energy Transfer International-journal Peer-reviewed

Takahisa Omata, Hiroshi Asano, Masahiro Sakai, Yoshikazu Terai, Masao Kita

The Journal of Physical Chemistry Letters　12　(12)　3120-3126　2021/04/01
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.jpclett.1c00165 　

ISSN： 1948-7185

eISSN： 1948-7185
Zn(Te1−Se ) quantum dots synthesized through a facile route and their band-edge and surface state driven visible-light emission International-journal Peer-reviewed

Satoshi Tsukuda, Masao Kita, Takahisa Omata

Journal of Luminescence　231　117829-117829　2021/03
Publisher: Elsevier BV
DOI： 10.1016/j.jlumin.2020.117829 　

ISSN： 0022-2313
SnS Homojunction Solar Cell with n‐Type Single Crystal and p‐Type Thin Film International-journal International-coauthorship Peer-reviewed

Sakiko Kawanishi, Issei Suzuki, Sage R. Bauers, Andriy Zakutayev, Hiroyuki Shibata, Hiroshi Yanagi, Takahisa Omata

Solar RRL　2000708-2000708　2021/02/25
Publisher: Wiley
DOI： 10.1002/solr.202000708 　

ISSN： 2367-198X

eISSN： 2367-198X
Investigating the role of GeO2 in enhancing the thermal stability and proton mobility of proton-conducting phosphate glasses International-journal International-coauthorship Peer-reviewed

Takahisa Omata, Aman Sharma, Takuya Kinoshita, Issei Suzuki, Tomohiro Ishiyama, Shinji Kohara, Koji Ohara, Madoka Ono, Tong Fang, Yang Ren, Masaya Fujioka, Gaoyang Zhao, Junji Nishii

Journal of Materials Chemistry A　9　(36)　20595-20606　2021

DOI： 10.1039/d1ta04445a 　

ISSN： 2050-7488

eISSN： 2050-7496
Understanding the effect of oxide components on proton mobility in phosphate glasses using a statical analysis approach International-journal Peer-reviewed

Takahisa Omata, Issei Suzuki, Aman Sharma, Tomohiro Ishiyama, Junji Nishii, Toshiharu Yamashita, Hiroshi Kawazoe

RSC Advances　11　(5)　3012-3019　2021

DOI： 10.1039/d0ra10327f 　

eISSN： 2046-2069
White-Light Emission from Zinc Chalcogenide Alloy Quantum Dots with Gradient Compositions International-journal Peer-reviewed

T. Omata, H. Asano, S. Tsukuda, M. Kita

J. Lumin　232　2021

DOI： 10.1016/j.jlumin.2020.117876 　

ISSN： 0022-2313
Surface modification of soda–lime–silicate glass via the high-temperature electrochemical injection of tin ions International-journal Peer-reviewed

Satoshi Miyasaka, Tomohiro Ishiyama, Masanori Nakano, Kazutaka Yanagihara, Yasuo Hayashi, Takahisa Omata

Applied Surface Science　532　147421-147421　2020/12
Publisher: Elsevier BV
DOI： 10.1016/j.apsusc.2020.147421 　

ISSN： 0169-4332
Fermi Energy Limitation at β-CuGaO2 Interfaces Induced by Electrochemical Oxidation/Reduction of Cu International-journal International-coauthorship Peer-reviewed

Issei Suzuki, Binxiang Huang, Takahisa Omata, Andreas Klein

ACS Applied Energy Materials　3　(9)　9117-9125　2020/09/28

DOI： 10.1021/acsaem.0c01493 　

ISSN： 2574-0962

eISSN： 2574-0962
Growth of Large Single Crystals of n-Type SnS from Halogen-Added Sn Flux International-journal Peer-reviewed

Sakiko Kawanishi, Issei Suzuki, Takeo Ohsawa, Naoki Ohashi, Hiroyuki Shibata, Takahisa Omata

Crystal Growth & Design　20　(9)　5931-5939　2020/09/02
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.cgd.0c00617 　

ISSN： 1528-7483

eISSN： 1528-7505
Thermal stability and proton conductivity of densely proton injected phosphate glasses containing rare-earth elements International-journal International-coauthorship Peer-reviewed

Atsushi Miyazaki, Takuya Kinoshita, Takashi Tatebayashi, Tong Fang, Yang Ren, Tomohiro Ishiyama, Takuya Yamaguchi, Takahisa Omata, Masaya Fujioka, Kaiju Hideo, Gaoyang Zhao, Junji Nishii

Journal of Non-Crystalline Solids　541　120064-120064　2020/08
Publisher: Elsevier BV
DOI： 10.1016/j.jnoncrysol.2020.120064 　

ISSN： 0022-3093
Quantum dot phosphors free from hazardous elements: Current status and prospects for established materials and new ZnTe‐based alloys International-journal Invited Peer-reviewed

Satoshi Tsukuda, Takahisa Omata

Journal of the Society for Information Display　28　(8)　680-690　2020/08
Publisher: Wiley
DOI： 10.1002/jsid.948 　

ISSN： 1071-0922

eISSN： 1938-3657
Control of the near‐surface OH concentration of float glass by anodic proton injection International-journal Peer-reviewed

Satoshi Miyasaka, Tomohiro Ishiyama, Yasuo Hayashi, Takahisa Omata

Journal of the American Ceramic Society　103　(6)　3642-3649　2020/06
Publisher: Wiley
DOI： 10.1111/jace.17068 　

ISSN： 0002-7820

eISSN： 1551-2916
Ultra-thin phosphate glass exhibiting high proton conductivity at intermediate temperatures International-journal Peer-reviewed

Issei Suzuki, Masataka Tashiro, Takuya Yamaguchi, Tomohiro Ishiyama, Junji Nishii, Toshiharu Yamashita, Hiroshi Kawazoe, Takahisa Omata

International Journal of Hydrogen Energy　45　(33)　16690-16697　2020/06
Publisher: Elsevier BV
DOI： 10.1016/j.ijhydene.2020.04.114 　

ISSN： 0360-3199
Formation of spherical, rod- And branch-shaped colloidal In<inf>2</inf>O<inf>3</inf> Nanocrystals through Simple Thermolysis of an Oleate Precursor International-journal Peer-reviewed

Satoshi Tsukuda, Hideo Uesugi, Masao Kita, Takahisa Omata

Materials Transactions　61　(3)　462-468　2020

DOI： 10.2320/matertrans.MT-M2019245 　

ISSN： 1345-9678
Fabrication and Morphological Control of Ni-Based Nanowires by Self-Assembled Solution Synthesis International-journal Peer-reviewed

S. Tsukuda, T. Omata

Mater. Trans　60　2188-2194　2019/10

DOI： 10.2320/matertrans.MT-M2019133 　
Synthesis and optical properties of cadmium‐free colloidal II–VI alloy quantum dot phosphor International-journal Invited

S. Tsukuda, H. Asano, T. Omata

SID Symposium Digest of Technical Papers　50　(S1)　405-405　2019/09

DOI： 10.1002/sdtp.13510 　
Transport properties of proton conducting phosphate glass: An electrochemical hydrogen pump enabling the formation of dry hydrogen gas International-journal Peer-reviewed

T. Ishiyama, H. Kishimoto, K. Yamaji, T. Yamaguchi, J. Nishii, T. Yamashita, H. Kawazoe, T. Omata

Int. J. Hydrogen Energy　44　(45)　24977-24984　2019/07

DOI： 10.1016/j.ijhydene.2019.07.213 　

ISSN： 0360-3199

eISSN： 1879-3487
Quantum Dot Phosphors Containing None of Hazardous Element; ZnTe‐Based Alloy Quantum Dots International-journal Invited

T. Omata, S. Tsukuda, H. Asano

SID Symposium Digest of Technical Papers　50　(1)　1160-1163　2019/05

DOI： 10.1002/sdtp.13136 　
Tunable direct band gap of β-CuGaO2 and β-LiGaO2 solid solutions in the full visible range International-journal Peer-reviewed

I. Suzuki, Y. Mizuno, T. Omata

Inorg. Chem.　58　(7)　4262-4267　2019/05

DOI： 10.1021/acs.inorgchem.8b03370 　

ISSN： 0020-1669

eISSN： 1520-510X
Proton transport properties of proton-conducting phosphate glasses at their glass transition temperatures International-journal Peer-reviewed

T. Omata, T. Yamaguchi, S. Tsukuda, T. Ishiyama, J. Nishii, T. Yamashita, H. Kawazoe

Phys. Chem. Chem. Phys　21　(20)　10744-10749　2019/05

DOI： 10.1039/C9CP01502G 　

ISSN： 1463-9076

eISSN： 1463-9084
Comprehensive first-principles study of AgGaO2 and CuGaO2 polymorphs International-journal Peer-reviewed

I. Suzuki, Y. Iguchi, C. Sato, H. Yanagi, N. Ohashi, T. Omata

J. Ceramc. Jpn.　127　(6)　339-347　2019/02

DOI： 10.2109/jcersj2.19025 　

ISSN： 1882-0743

eISSN： 1348-6535
Flux growth of β-NaGaO2 single crystals International-journal Peer-reviewed

Suzuki, I, Kakinuma, A, Ueda, M, Omata, T

Journal of Crystal Growth　504　26-30　2018/12

DOI： 10.1016/j.jcrysgro.2018.09.034 　

ISSN： 0022-0248
Proton-conducting phosphate glass and its melt exhibiting high electrical conductivity at intermediate temperatures International-journal Peer-reviewed

Yamaguchi, T, Tsukuda, S, Ishiyama, T, Nishii, J, Yamashita, T, Kawazoe, H, Omata, T

Journal of Materials Chemistry A　6　(46)　23628-23637　2018/11

DOI： 10.1039/C8TA08162J 　

ISSN： 2050-7488

eISSN： 2050-7496
Controlling the electrical conductivity of ternary wurtzite-type and metastable β-AgGaO2 by impurity doping International-journal Peer-reviewed

H. Nagatani, I. Suzuki, S. Takemura, T. Ohsawa, N. Ohashi, S. Fujimoto, T. Omata

AIP Advances　8　(8)　85203-1-85203-9　2018/08

DOI： 10.1063/1.5046361 　

eISSN： 2158-3226
Catalytic CO oxidation of Palladium Nanoparticles Formed by One-step Synthesis on Polycarbosilane Nanowires International-journal Peer-reviewed

S. Tsukuda, A. Idesaki, M. Sugimoto, S. Seki, T. Omata

Mater. Res. Express　5　(8)　085003-1-085003-8　2018/07/18

DOI： 10.1088/2053-1591/aad122 　
Colloidal Zn(Te,Se)/ZnS Core/Shell Quantum Dots Exhibiting Narrow-Band and Green Photoluminescence International-journal Peer-reviewed

Hiroshi Asano, Satoshi Tsukuda, Masao Kita, Shinji Fujimoto, Takahisa Omata

ACS Omega　3　(6)　6703-6709　2018/06/30
Publisher: American Chemical Society
DOI： 10.1021/acsomega.8b00612 　

ISSN： 2470-1343

eISSN： 2470-1343
Dense proton injection into phosphate glasses using corona discharge treatment International-journal Peer-reviewed

Takuya Kinoshita, Atsushi Miyazaki, Keiga Kawaguchi, Daisuke Sakai, Takuya Yamaguchi, Takahisa Omata, Tomohiro Ishiyama, Masaya Fujioka, Hideo Kaiju, Junji Nishii

APPLIED SURFACE SCIENCE　428　718-722　2018/01

DOI： 10.1016/j.apsusc.2017.09.186 　

ISSN： 0169-4332

eISSN： 1873-5584
Fabrication of Au nanoparticles on poly(vinylpyrrolidone) nanowires exhibiting reversible frequency change of localized surface plasmon resonance International-journal Peer-reviewed

Satoshi Tsukuda, Shu Seki, Masaaki Omichi, Masaki Sugimoto, Akira Idesaki, Tohru Sekino, Takahisa Omata

AIP Advances　8　(1)　015314-1-015314-9　2018/01/01
Publisher: American Institute of Physics Inc.
DOI： 10.1063/1.5001553 　

ISSN： 2158-3226
Orientation control of β-NaGaO2 thin film: A precursor for β-CuGaO2 as a thin-film solar cell absorber International-journal Peer-reviewed

Issei Suzuki, Masatoshi Tanemura, Takahisa Omata

Journal of the Ceramic Society of Japan　125　(12)　872-875　2017/12/01
Publisher: Ceramic Society of Japan
DOI： 10.2109/jcersj2.17157 　

ISSN： 1348-6535 1882-0743

eISSN： 1348-6535
Wurtzite-Derived Quaternary Oxide Semiconductor Cu2ZnGeO4: Its Structural Characteristics, Optical Properties, and Electronic Structure International-journal Peer-reviewed

Masao Kita, Issei Suzuki, Naoki Ohashi, Takahisa Omata

INORGANIC CHEMISTRY　56　(22)　14277-14283　2017/11

DOI： 10.1021/acs.inorgchem.7b02379 　

ISSN： 0020-1669

eISSN： 1520-510X
Formation of Amorphous H3Zr2Si2PO12 by Electrochemical Substitution of Sodium Ions in Na3Zr2Si2PO12 with Protons International-journal Peer-reviewed

Satoshi Tsukuda, Keigo Miyake, Takuya Yamaguchi, Masao Kita, Tomohiro Ishiyama, Junji Nishii, Toshiharu Yamashita, Hiroshi Kawazoe, Takahisa Omata

INORGANIC CHEMISTRY　56　(22)　13949-13954　2017/11

DOI： 10.1021/acs.inorgchem.7b02060 　

ISSN： 0020-1669

eISSN： 1520-510X
The mobility of proton carriers in phosphate glasses depends on polymerization of the phosphate framework International-journal Peer-reviewed

Takuya Yamaguchi, Takuya Kataoka, Satoshi Tsukuda, Tomohiro Ishiyama, Junji Nishii, Toshiharu Yamashita, Hiroshi Kawazoe, Takahisa Omata

PHYSICAL CHEMISTRY CHEMICAL PHYSICS　19　(43)　29669-29675　2017/11

DOI： 10.1039/c7cp05241c 　

ISSN： 1463-9076

eISSN： 1463-9084
Synthesis of colloidal Zn(Te,Se) alloy quantum dots International-journal Peer-reviewed

H. Asano, K. Arai, M. Kita, T. Omata

MATERIALS RESEARCH EXPRESS　4　(10)　106501-1-106501-10　2017/10

DOI： 10.1088/2053-1591/aa8b84 　

ISSN： 2053-1591
Fabrication of beta-CuGaO2 thin films by ion-exchange of beta-NaGaO2 thin films International-journal Peer-reviewed

Issei Suzuki, Hiraku Nagatani, Masao Kita, Takahisa Omata

APPLIED PHYSICS EXPRESS　10　(9)　095501-1-095501-4　2017/09

DOI： 10.7567/APEX.10.095501 　

ISSN： 1882-0778

eISSN： 1882-0786
Formation of Au nanoparticle arrays on hydrogel two-dimensional patterns based on poly(vinylpyrrolidone) International-journal Peer-reviewed

Satoshi Tsukuda, Kazumasa Okamoto, Hiroki Yamamoto, Takahiro Kozawa, Takahisa Omata

JAPANESE JOURNAL OF APPLIED PHYSICS　56　(6)　06GG06-1-06GG06-4　2017/06

DOI： 10.7567/JJAP.56.06GG06 　

ISSN： 0021-4922

eISSN： 1347-4065
Effect of alkaline-earth species in phosphate glasses on the mobility of proton carriers International-journal Peer-reviewed

Takuya Yamaguchi, Yasuhisa Saito, Yasutaka Kuwahara, Hiromi Yamashita, Tomohiro Ishiyama, Junji Nishii, Toshiharu Yamashita, Hiroshi Kawazoe, Takahisa Omata

JOURNAL OF MATERIALS CHEMISTRY A　5　(24)　12385-12392　2017/06

DOI： 10.1039/c7ta01475a 　

ISSN： 2050-7488

eISSN： 2050-7496
Variation of crystal structure and optical properties of wurtzite-type oxide semiconductor alloys of beta-Cu(Ga,Al)O-2 International-journal Peer-reviewed

Hiraku Nagatani, Yuki Mizuno, Issei Suzuki, Masao Kita, Naoki Ohashi, Takahisa Omata

JOURNAL OF APPLIED PHYSICS　121　(23)　235103-1-235103-8　2017/06

DOI： 10.1063/1.4985700 　

ISSN： 0021-8979

eISSN： 1089-7550
Design of cadmium-free colloidal II-VI semiconductor quantum dots exhibiting RGB emission International-journal Peer-reviewed

Hiroshi Asano, Takahisa Omata

AIP ADVANCES　7　(4)　045309-1-045309-7　2017/04

DOI： 10.1063/1.4982256 　

ISSN： 2158-3226
Multinary wurtzite-type oxide semiconductors: present status and perspectives International-journal Invited Peer-reviewed

Issei Suzuki, Takahisa Omata

SEMICONDUCTOR SCIENCE AND TECHNOLOGY　32　(1)　013007-1-013007-17　2017/01

DOI： 10.1088/1361-6641/32/1/013007 　

ISSN： 0268-1242

eISSN： 1361-6641
High temperature phases with wurtzite-derived structure in Zn2LiGaO4-ZnO alloy system International-journal Peer-reviewed

Masao Kita, Tomoaki Fukada, Shu Yamaguchi, Takahisa Omata

JOURNAL OF ALLOYS AND COMPOUNDS　688　69-76　2016/12

DOI： 10.1016/j.jallcom.2016.06.249 　

ISSN： 0925-8388

eISSN： 1873-4669
First-Principles Study of CuGaO2 Polymorphs: Delafossite alpha-CuGaO2 and Wurtzite beta-CuGaO2 International-journal Peer-reviewed

Issei Suzuki, Hiraku Nagatani, Masao Kita, Yuki Iguchi, Chiyuki Sato, Hiroshi Yanagi, Naoki Ohashi, Takahisa Omata

INORGANIC CHEMISTRY　55　(15)　7610-7616　2016/08

DOI： 10.1021/acs.inorgchem.6b01012 　

ISSN： 0020-1669

eISSN： 1520-510X
Relationship between structure and mobility of proton carriers injected by electrochemical substitution of sodium ions with protons in 35NaO(1/2)-1 WO3-8NbO(5/2)-5LaO(3/2)-51PO(5/2)-based glasses International-journal Peer-reviewed

Takuya Yamaguchi, Tomohiro Ishiyama, Kanji Sakuragi, Junji Nishii, Toshiharu Yamashita, Hiroshi Kawazoe, Naoaki Kuwata, Junichi Kawamura, Takahisa Omata

SOLID STATE IONICS　288　281-285　2016/05

DOI： 10.1016/j.ssi.2016.01.024 　

ISSN： 0167-2738

eISSN： 1872-7689
First principles calculations of ternary wurtzite beta-CuGaO2 International-journal Peer-reviewed

Issei Suzuki, Hiraku Nagatani, Masao Kita, Yuki Iguchi, Chiyuki Sato, Hiroshi Yanagi, Naoki Ohashi, Takahisa Omata

JOURNAL OF APPLIED PHYSICS　119　(9)　095701　2016/03

DOI： 10.1063/1.4942619 　

ISSN： 0021-8979

eISSN： 1089-7550
Ternary and quaternary wurtzite-type oxide semiconductors: beta-CuGaO2 and its related materials International-journal Peer-reviewed

Takahisa Omata, Yuki Mizuno, Issei Suzuki, Hiraku Nagatani, Masao Kita

2016 COMPOUND SEMICONDUCTOR WEEK (CSW) INCLUDES 28TH INTERNATIONAL CONFERENCE ON INDIUM PHOSPHIDE & RELATED MATERIALS (IPRM) & 43RD INTERNATIONAL SYMPOSIUM ON COMPOUND SEMICONDUCTORS (ISCS)　2016
Improving thermal stability and its effects on proton mobility in proton-conducting phosphate glasses prepared by the electrochemical substitution of sodium ions with protons International-journal Peer-reviewed

Takuya Yamaguchi, Tomohiro Ishiyama, Kanji Sakuragi, Junji Nishii, Toshiharu Yamashita, Hiroshi Kawazoe, Takahisa Omata

SOLID STATE IONICS　275　62-65　2015/07

DOI： 10.1016/j.ssi.2015.03.003 　

ISSN： 0167-2738

eISSN： 1872-7689
Synthesis of size-controlled colloidal InAs quantum dots using triphenylarsine as a stable arsenic source International-journal Peer-reviewed

Hideo Uesugi, Masao Kita, Takahisa Omata

JOURNAL OF CRYSTAL GROWTH　416　134-141　2015/04

DOI： 10.1016/j.jcrysgro.2015.01.031 　

ISSN： 0022-0248

eISSN： 1873-5002
Wurtzite-derived ternary I-III-O-2 semiconductors International-journal Peer-reviewed

Takahisa Omata, Hiraku Nagatani, Issei Suzuki, Masao Kita

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS　16　(2)　024902　2015/04

DOI： 10.1088/1468-6996/16/2/024902 　

ISSN： 1468-6996

eISSN： 1878-5514
Structure of beta-AgGaO2; ternary I-III-VI2 oxide semiconductor with a wurtzite-derived structure International-journal Peer-reviewed

Hiraku Nagatani, Issei Suzuki, Masao Kita, Masahiko Tanaka, Yoshio Katsuya, Osami Sakata, Takahisa Omata

JOURNAL OF SOLID STATE CHEMISTRY　222　66-70　2015/02

DOI： 10.1016/j.jssc.2014.11.012 　

ISSN： 0022-4596

eISSN： 1095-726X
Structural and Thermal Properties of Ternary Narrow-Gap Oxide Semiconductor; Wurtzite-Derived beta-CuGaO2 International-journal Peer-reviewed

Hiraku Nagatani, Issei Suzuki, Masao Kita, Masahiko Tanaka, Yoshio Katsuya, Osami Sakata, Shogo Miyoshi, Shu Yamaguchi, Takahisa Omata

INORGANIC CHEMISTRY　54　(4)　1698-1704　2015/02

DOI： 10.1021/ic502659e 　

ISSN： 0020-1669

eISSN： 1520-510X
Widely bandgap tunable amorphous Cd-Ga-O oxide semiconductors exhibiting electron mobilities >= 10 cm(2) V-1 s(-1) International-journal Peer-reviewed

Hiroshi Yanagi, Chiyuki Sato, Yota Kimura, Issei Suzuki, Takahisa Omata, Toshio Kamiya, Hideo Hosono

APPLIED PHYSICS LETTERS　106　(8)　082106　2015/02

DOI： 10.1063/1.4913691 　

ISSN： 0003-6951

eISSN： 1077-3118
Colloidal semiconductor quantum dots; syntheses, properties and applications International-journal Peer-reviewed

Takahisa Omata

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　123　(1433)　1-8　2015/01

DOI： 10.2109/jcersj2.123.1 　

ISSN： 1882-0743

eISSN： 1348-6535
硫化製錬における非鉄金属とNaのマット‐スラグ間の分配 Peer-reviewed

門前兼廣, 松尾伸也, 小俣孝久

J. MMIJ　131　65-73　2015
Structural change of NaO1/2-WO3-NbO5/2-LaO3/2-PO5/2 glass induced by electrochemical substitution of sodium ions with protons International-journal Peer-reviewed

Tomohiro Ishiyama, Takuya Yamaguchi, Junji Nishii, Toshiharu Yamashita, Hiroshi Kawazoe, Naoaki Kuwata, Junichi Kawamura, Takahisa Omata

PHYSICAL CHEMISTRY CHEMICAL PHYSICS　17　(20)　13640-13646　2015

DOI： 10.1039/c4cp05999a 　

ISSN： 1463-9076

eISSN： 1463-9084
高品位銅マットからのNi, Co濃縮相の抽出分離 Peer-reviewed

門前兼廣, 松尾伸也, 小俣孝久

J. MMIJ　131　487-496　2015

DOI： 10.2473/journalofmmij.131.487 　
Phase separation and crystallization in sodium lanthanum phosphate glasses induced by electrochemical substitution of sodium ions with protons International-journal Peer-reviewed

Keiga Kawaguchi, Takuya Yamaguchi, Takahisa Omata, Toshiharu Yamashita, Hiroshi Kawazoe, Junji Nishii

PHYSICAL CHEMISTRY CHEMICAL PHYSICS　17　(35)　22855-22861　2015

DOI： 10.1039/c5cp04132e 　

ISSN： 1463-9076

eISSN： 1463-9084
Facile synthesis of colloidal InAs nanocrystals using triphenylarsine as an arsenic source International-journal Peer-reviewed

Hideo Uesugi, Masao Kita, Takahisa Omata

JOURNAL OF CRYSTAL GROWTH　405　39-43　2014/11

DOI： 10.1016/j.jcrysgro.2014.07.037 　

ISSN： 0022-0248

eISSN： 1873-5002
alpha-PbO2-related phase appearing in the Sn-IV-Ta-O system transformed from cation-ordered fluorite-related phase Peer-reviewed

Masao Kita, Takahisa Omata, Shinya Otsuka-Yao-Matsuo, Motomi Katada

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　122　(1430)　902-907　2014/10

DOI： 10.2109/jcersj2.122.902 　

ISSN： 1882-0743

eISSN： 1348-6535
Proton conducting tungsten phosphate glass and its application in intermediate temperature fuel cells International-journal Peer-reviewed

T. Ishiyama, S. Suzuki, J. Nishii, T. Yamashita, H. Kawazoe, T. Omata

SOLID STATE IONICS　262　856-859　2014/09

DOI： 10.1016/j.ssi.2013.10.055 　

ISSN： 0167-2738

eISSN： 1872-7689
Enhancement by praseodymium addition of catalytic activity of nickel supported on cerium-zirconium oxide in methane steam reforming International-journal Peer-reviewed

Tomohiro Ishiyama, Kota Kurimoto, Masao Kita, Shinya Otsuka-Yao-Matsuo, Takahisa Omata

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　122　(1427)　537-542　2014/07

DOI： 10.2109/jcersj2.122.537 　

ISSN： 1882-0743

eISSN： 1348-6535
Fabrication of beta-AgGaO2 thin films by radio frequency magnetron sputtering International-journal Peer-reviewed

Issei Suzuki, Hiraku Nagatani, Yuta Arima, Masao Kita, Takahisa Omata

THIN SOLID FILMS　559　112-115　2014/05

DOI： 10.1016/j.tsf.2013.10.099 　

ISSN： 0040-6090
Phase determination of zinc selenide nanocrystals depending on the ligand species of precursor complexes International-journal Peer-reviewed

Takahisa Omata, Hideo Uesugi, Masao Kita

JOURNAL OF CRYSTAL GROWTH　394　81-88　2014/05

DOI： 10.1016/j.jcrysgro.2014.02.019 　

ISSN： 0022-0248

eISSN： 1873-5002
Synthesis of colloidal solution of beta-LiGaO2 nanocrystals capped with organic surfactant International-journal Peer-reviewed

Kazuyuki Takahashi, Yasuhiro Maeda, Takashi Suehiro, Masao Kita, Takahisa Omata

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　122　(1423)　195-197　2014/03

DOI： 10.2109/jcersj2.122.195 　

ISSN： 1882-0743

eISSN： 1348-6535
Wurtzite CuGaO2: A New Direct and Narrow Band Gap Oxide Semiconductor Applicable as a Solar Cell Absorber International-journal Peer-reviewed

Takahisa Omata, Hiraku Nagatani, Issei Suzuki, Masao Kita, Hiroshi Yanagi, Naoki Ohashi

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY　136　(9)　3378-3381　2014/03

DOI： 10.1021/ja501614n 　

ISSN： 0002-7863
Electrochemical substitution of sodium ions with protons in phosphate glass to fabricate pure proton conducting glass at intermediate temperatures International-journal Peer-reviewed

T. Ishiyama, J. Nishii, T. Yamashita, H. Kawazoe, T. Omata

JOURNAL OF MATERIALS CHEMISTRY A　2　(11)　3940-3947　2014

DOI： 10.1039/c3ta14561a 　

ISSN： 2050-7488

eISSN： 2050-7496
廃棄物の硫化製錬における鉄と非鉄金属元素の分配について Peer-reviewed

門前兼廣, 松尾伸也, 小俣孝久

J. MMIJ　130　115-124　2014

DOI： 10.2473/journalofmmij.130.115 　
Electronic transition responsible for size-dependent photoluminescence of colloidal CuInS2 quantum dots Peer-reviewed

Takahisa Omata, Katsuhiro Nose, Kohta Kurimoto, Masao Kita

JOURNAL OF MATERIALS CHEMISTRY C　2　(33)　6867-6872　2014

DOI： 10.1039/c4tc01144a 　

ISSN： 2050-7526

eISSN： 2050-7534
Pseudo-binary alloying system of ZnO-AgGaO2 reducing the energy band gap of zinc oxide Peer-reviewed

I. Suzuki, H. Nagatani, Y. Arima, M. Kita, T. Omata

APPLIED PHYSICS LETTERS　103　(22)　222107　2013/11

DOI： 10.1063/1.4836435 　

ISSN： 0003-6951

eISSN： 1077-3118
Fabrication of ZnF2 thin films and their vacuum ultraviolet transparency Peer-reviewed

Issei Suzuki, Takahisa Omata, Yu Shiratsuchi, Ryoichi Nakatani, Naoyuki Kitamura, Shinya Otsuka-Yao-Matsuo

THIN SOLID FILMS　534　508-514　2013/05

DOI： 10.1016/j.tsf.2013.02.071 　

ISSN： 0040-6090

eISSN： 1879-2731
Impact of the Electrical Forming Process on the Resistance Switching Behaviors in Lanthanum-Doped Strontium Titanate Ceramic Chip Devices Peer-reviewed

Sakyo Hirose, Hideaki Niimi, Keisuke Kageyama, Akira Ando, Hideharu Ieki, Takahisa Omata

JAPANESE JOURNAL OF APPLIED PHYSICS　52　(4)　045802　2013/04

DOI： 10.7567/JJAP.52.045802 　

ISSN： 0021-4922
Electrochemical Substitution of Sodium Ions in Tungsten Phosphate Glass with Protons Peer-reviewed

T. Ishiyama, S. Suzuki, J. Nishii, T. Yamashita, H. Kawazoe, T. Omata

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　160　(11)　E143-E147　2013

DOI： 10.1149/2.093311jes 　

ISSN： 0013-4651

eISSN： 1945-7111
Degradation of potential barriers in ZnO-based chip varistors due to electrostatic discharge Peer-reviewed

Sakyo Hirose, Hideaki Niimi, Keisuke Kageyama, Hideharu Ieki, Takahisa Omata, Shinya Otsuka-Yao-Matsuo

JOURNAL OF APPLIED PHYSICS　112　(3)　033707(1)-033707(11)　2012/08

DOI： 10.1063/1.4742987 　

ISSN： 0021-8979
Structural variation and optical properties of ZnO-LiGaO2 pseudo-binary system Peer-reviewed

Takahisa Omata, Masao Kita, Kosuke Tachibana, Shinya Otsuka-Yao-Matsuo

JOURNAL OF SOLID STATE CHEMISTRY　188　92-99　2012/04

DOI： 10.1016/j.jssc.2012.01.053 　

ISSN： 0022-4596
Quantum dot phosphors and their application to inorganic electroluminescence device Peer-reviewed

Takahisa Omata, Yuki Tani, Satoshi Kobayashi, Shinya Otsuka-Yao-Matsuo

THIN SOLID FILMS　520　(10)　3829-3834　2012/03

DOI： 10.1016/j.tsf.2011.10.057 　

ISSN： 0040-6090
Ultraviolet electroluminescence from colloidal ZnO quantum dots in an all-inorganic multilayer light-emitting device Peer-reviewed

T. Omata, Y. Tani, S. Kobayashi, K. Takahashi, A. Miyanaga, Y. Maeda, S. Otsuka-Yao-Matsuo

APPLIED PHYSICS LETTERS　100　(6)　061104　2012/02

DOI： 10.1063/1.3682307 　

ISSN： 0003-6951
Synthesis of LiGaO2 nanocrystals and their application toward bright UV emission from ZnO quantum dots Peer-reviewed

Takahisa Omata, Atsushi Tazuke, Katsuhiro Nose, Shinya Otsuka-Yao-Matsuo

JOURNAL OF CRYSTAL GROWTH　330　(1)　9-16　2011/09

DOI： 10.1016/j.jcrysgro.2011.06.032 　

ISSN： 0022-0248
Fabrication of Core-Shell-Type Copper Indium Selenide and Zinc Selenide Composite Quantum Dots and Their Optical Properties Peer-reviewed

Takahisa Omata, Katsuhiro Nose, Shinya Otsuka-Yao-Matsuo

JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY　11　(6)　4815-4823　2011/06

DOI： 10.1166/jnn.2011.4181 　

ISSN： 1533-4880
Fabrication of ZnO Films Alloyed with LiGaO2 by RF-Magnetron Sputtering and Their Optical Property Peer-reviewed

Takahisa Omata, Keizo Tanaka, Shinya Otsuka-Yao-Matsuo

JAPANESE JOURNAL OF APPLIED PHYSICS　50　(6)　061102　2011/06

DOI： 10.1143/JJAP.50.061102 　

ISSN： 0021-4922
UV luminescent organic-capped ZnO quantum dots synthesized by alkoxide hydrolysis with dilute water Peer-reviewed

Takahisa Omata, Kazuyuki Takahashi, Shinichi Hashimoto, Yasuhiro Maeda, Katsuhiro Nose, Shinya Otsuka-Yao-Matsuo, Kenji Kanaori

JOURNAL OF COLLOID AND INTERFACE SCIENCE　355　(2)　274-281　2011/03

DOI： 10.1016/j.jcis.2010.12.014 　

ISSN： 0021-9797
Zn2LiGaO4, Wurtzite- Derived Wide Band Gap Oxide Peer-reviewed

Takahisa Omata, Masao Kita, Katsuhiro Nose, Kosuke Tachibana, Shinya Otsuka-Yao-Matsuo

JAPANESE JOURNAL OF APPLIED PHYSICS　50　(3)　031102　2011/03

DOI： 10.1143/JJAP.50.031102 　

ISSN： 0021-4922
Synthesis of organic capped colloidal zinc oxide quantum dots and their UV dominant emission property

Takahisa Omata, Kazuyuki Takahashi, Shinichi Hashimoto, Yasuhiro Maeda, Katsuhiro Nose, Shinya Otsuka-Yao-Matsuo

Materials Research Society Symposium Proceedings　1207　31-36　2010

ISSN： 0272-9172
Synthesis of CuInS2 nanocrystals and their structural transformation triggered by ligand exchange Peer-reviewed

Nose Katsuhiro, Soma Yuki, Omata Takahisa, Otsuka-Yao-Matsuo Shinya

CHINESE SCIENCE BULLETIN　54　(21)　4005-4008　2009/11

DOI： 10.1007/s11434-009-0153-z 　

ISSN： 1001-6538
Synthesis of Ternary CuInS2 Nanocrystals; Phase Determination by Complex Ligand Species Peer-reviewed

Katsuhiro Nose, Yuki Soma, Takahisa Omata, Shinya Otsuka-Yao-Matsuo

CHEMISTRY OF MATERIALS　21　(13)　2607-2613　2009/07

DOI： 10.1021/cm802022p 　

ISSN： 0897-4756
Cu-Doped Zr-Ce-Pr-O Mixed Oxide Phases with High Oxygen Storage Capacity (OSC) Peer-reviewed

Tadatoshi Murota, Kosuke Sogawa, Shinya Otsuka-Yao-Matsuo, Takahisa Omata

JOURNAL OF THE JAPAN INSTITUTE OF METALS　73　(4)　268-274　2009/04

ISSN： 0021-4876

eISSN： 1880-6880
Size dependent optical band gap of ternary I-III-VI2 semiconductor nanocrystals Peer-reviewed

Takahisa Omata, Katsuhiro Nose, Shinya Otsuka-Yao-Matsuo

JOURNAL OF APPLIED PHYSICS　105　(7)　073106-1-073106-5　2009/04

DOI： 10.1063/1.3103768 　

ISSN： 0021-8979
Colloidal Synthesis of Ternary Copper Indium Diselenide Quantum Dots and Their Optical Properties Peer-reviewed

Katsuhiro Nose, Takahisa Omata, Shinya Otsuka-Yao-Matsuo

JOURNAL OF PHYSICAL CHEMISTRY C　113　(9)　3455-3460　2009/03

DOI： 10.1021/jp809398k 　

ISSN： 1932-7447
Synthesis of CuInS2 colloidal nanocrystals and their optical properties

Katsuhiro Nose, Yuki Soma, Takahisa Omata, Shinya Otsuka-Yao-Matsuo

The Minerals, Metals and Materials Society - 3rd International Conference on Processing Materials for Properties 2008, PMP III　2　818-823　2009
Extremely Suppressed Grain Growth of Y2O3-Stabilized Zirconia Nanocrystals Synthesized by the Nonhydrolytic Sol-Gel Technique Peer-reviewed

Yuji Goto, Takahisa Omata, Shinya Otsuka-Yao-Matsuo

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　156　(1)　K4-K9　2009

DOI： 10.1149/1.3021010 　

ISSN： 0013-4651
Novel wide band gap alloyed semiconductors, x(LiGaO2)(1/2)-(1-x)ZnO, and fabrication of their thin films Peer-reviewed

T. Omata, K. Tanaka, A. Tazuke, K. Nose, S. Otsuka-Yao-Matsuo

SCIENCE IN CHINA SERIES E-TECHNOLOGICAL SCIENCES　52　(1)　111-115　2009/01

DOI： 10.1007/s11431-008-0335-y 　

ISSN： 1006-9321
A Cu-added Zr-Ce-Sn-Pr-O mixed oxide phase with a high oxygen storage capacity Peer-reviewed

Tadatoshi Murota, Kosuke Sogawa, Shinya Otsuka-Yao-Matsuo, Takahisa Omata

Journal of Physics: Conference Series　165　012090　2009
Publisher: Institute of Physics Publishing
DOI： 10.1088/1742-6596/165/1/012090 　

ISSN： 1742-6596 1742-6588
Zr-Ce-Pr-O系酸化物の相平衡と酸素放出・吸収特性 Peer-reviewed

室田忠俊, 曽川幸助, 松尾伸也, 小俣孝久

日本金属学会誌　73　262-267　2009
Photoluminescence of CuInS2-based semiconductor quantum dots; Its origin and the effect of ZnS coating Peer-reviewed

Katsuhiro Nose, Naoya Fujita, Takahisa Omata, Shinya Otsuka-Yao-Matsuo, Wataru Kato, Masato Uehara, Hiroyuki Nakamura, Hideaki Maeda, Hayato Kamioka, Hideo Hosono

Journal of Physics: Conference Series　165　012028　2009
Publisher: Institute of Physics Publishing
DOI： 10.1088/1742-6596/165/1/012028 　

ISSN： 1742-6596 1742-6588
Synthesis of Y2O3-doped CeO2 nanocrystals and their surface modification Peer-reviewed

Yuji Goto, Kazuyuki Takahashi, Takahisa Omata, Shinya Otsuka-Yao-Matsuo

Journal of Physics: Conference Series　165　012041　2009
Publisher: Institute of Physics Publishing
DOI： 10.1088/1742-6596/165/1/012041 　

ISSN： 1742-6596 1742-6588
Mixed dopant effect in SrZrO3-based proton conductor Peer-reviewed

Takahisa Omata, Tomonao Fuke, Shinya Otsuka-Yao-Matsuo

SOLID STATE IONICS　179　(21-26)　1116-1119　2008/09

DOI： 10.1016/j.ssi.2008.01.029 　

ISSN： 0167-2738
Formation of Ni3C nanocrystals by thermolysis of nickel acetylacetonate in oleylamine: Characterization using hard X-ray photoelectron spectroscopy Peer-reviewed

Yuji Goto, Kota Taniguchi, Takahisa Omata, Shinya Otsuka-Yao-Matsuo, Naoki Ohashi, Shigenori Ueda, Hideki Yoshikawa, Yoshiyuki Yamashita, Hirofumi Oohashi, Keisuke Kobayashi

CHEMISTRY OF MATERIALS　20　(12)　4156-4160　2008/06

DOI： 10.1021/cm703644x 　

ISSN： 0897-4756
Wide band gap semiconductor alloy: x(LiGaO(2))(1/2)-(1-x)ZnO Peer-reviewed

Takahisa Omata, Keizo Tanaka, Atsushi Tazuke, Katsuhiro Nose, Shinya Otsuka-Yao-Matsuo

JOURNAL OF APPLIED PHYSICS　103　(8)　083706　2008/04

DOI： 10.1063/1.2903906 　

ISSN： 0021-8979
Chemical role of amines in the colloidal synthesis of CdSe quantum dots and their luminescence properties Peer-reviewed

Katsuhiro Nose, Hiroshi Fujita, Takahisa Omata, Shinya Otsuka-Yao-Matsuo, Hiroyuki Nakamura, Hideaki Maeda

JOURNAL OF LUMINESCENCE　126　(1)　21-26　2007/09

DOI： 10.1016/j.jlumin.2006.04.009 　

ISSN： 0022-2313
Nanocrystals of zirconia- and ceria-based solid electrolytes: Syntheses and properties Peer-reviewed

Takahisa Omata, Yuji Goto, Shinya Otsuka-Yao-Matsuo

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS　8　(6)　524-530　2007/09

DOI： 10.1016/j.stam.2007.09.001 　

ISSN： 1468-6996
Hydration behavior of Ba2Sc2O5 with an oxygen-deficient perovskite structure Peer-reviewed

Takahisa Omata, Tomonao Fuke, Shinya Otsuka-Yao-Matsuo

SOLID STATE IONICS　177　(26-32)　2447-2451　2006/10

DOI： 10.1016/j.ssi.2006.05.044 　

ISSN： 0167-2738
Tunable photoluminescence wavelength of chalcopyrite CuInS2-based semiconductor nanocrystals synthesized in a colloidal system Peer-reviewed

Hiroyuki Nakamura, Wataru Kato, Masato Uehara, Katsuhiro Nose, Takahisa Omata, Shinya Otsuka-Yao-Matsuo, Masaya Miyazaki, Hideaki Maeda

CHEMISTRY OF MATERIALS　18　(14)　3330-3335　2006/07

DOI： 10.1021/cm0518022 　

ISSN： 0897-4756

eISSN： 1520-5002
Characterization of indium-tin oxide sputtering targets showing various densities of nodule formation Peer-reviewed

T Omata, M Kita, H Okada, S Otsuka-Yao-Matsuo, N Ono, H Ikawa

THIN SOLID FILMS　503　(1-2)　22-28　2006/05

DOI： 10.1016/j.tsf.2005.09.200 　

ISSN： 0040-6090
Synthesis of CeO2, ZrO2 nanocrystals, and core-shell-type nanocomposites Peer-reviewed

Takahisa Omata, Shigeru Sasai, Yuji Goto, Masato Ueda, Shinya Otsuka-Yao-Matsuo

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　153　(12)　A2269-A2273　2006

DOI： 10.1149/1.2360765 　

ISSN： 0013-4651
Infrared study of high temperature proton conducting Sr(Zr0.95M0.05III)O3-delta; formation of (MO6)-O-III-cluster depends on dopant species Peer-reviewed

T Omata, Y Noguchi, S Otsuka-Yao-Matsuo

SOLID STATE IONICS　176　(39-40)　2941-2944　2005/12

DOI： 10.1016/j.ssi.2005.09.026 　

ISSN： 0167-2738
Synthesis of novel cation-ordered compounds with fluorite-related structure prepared by oxidation of Sn-Ta-O pyrochlore Peer-reviewed

M Kita, T Omata, S Otsuka-Yao-Matsuoa, M Katada

JOURNAL OF SOLID STATE CHEMISTRY　178　(4)　1254-1261　2005/04

DOI： 10.1016/j.jssc.2005.01.029 　

ISSN： 0022-4596

eISSN： 1095-726X
Characterization of novel cation-ordered compounds with fluorite and alpha-PbO2 related structures prepared by oxidation of Sn-Nb-O pyrochlore Peer-reviewed

T Omata, M Kita, S Otsuka-Yao-Matsuoa, M Katada

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS　66　(1)　53-62　2005/01

DOI： 10.1016/j.jpcs.2004.08.031 　

ISSN： 0022-3697

eISSN： 1879-2553
Synthesis of CdSe quantum dots using micro-flow reactor and their optical properties Peer-reviewed

T Omata, K Nose, S Otsuka-Yao-Matsuo, H Nakamura, H Maeda

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS　44　(1A)　452-456　2005/01

ISSN： 0021-4922
Electrical conduction properties of sr-doped LaPO4 and CePO4 under oxidizing and reducing conditions Peer-reviewed

N Kitamura, K Amezawa, Y Tomii, T Hanada, N Yamamoto, T Omata, S Otsuka-Yao-Matsuo

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　152　(4)　A658-A663　2005

DOI： 10.1149/1.1861993 　

ISSN： 0013-4651
Infrared study of high-temperature proton-conducting aliovalently doped SrZrO3 and BaZrO3 Peer-reviewed

T Omata, Y Noguchi, S Otsuka-Yao-Matsuo

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　152　(6)　E200-E205　2005

DOI： 10.1149/1.1899269 　

ISSN： 0013-4651
Formation and thermal stability of hydrate-like compounds of Ba-2(In1-xMxIII)(2)O-5 center dot nH(2)O (M-III = Ga, Sc, Lu, and Y) Peer-reviewed

T Omata, M Kita, Y Goto, T Okura, S Otsuka-Yao-Matsuo

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　152　(6)　A1068-A1072　2005

DOI： 10.1149/1.1900983 　

ISSN： 0013-4651
Synthesis of novel compounds with cation ordered fluorite and alpha-PbO2 related structures by oxidation of Sn(2)Nb(2)O(7)pyrochlore Peer-reviewed

T Omata, M Kita, S Otsuka-Yao-Matsuo, M Katada

JOURNAL OF ALLOYS AND COMPOUNDS　370　(1-2)　80-89　2004/05

DOI： 10.1016/j.jallcom.2003.08.090 　

ISSN： 0925-8388
O-H stretching vibrations of proton conducting alkaline-earth zirconates Peer-reviewed

T Omata, M Takagi, S Otsuka-Yao-Matsuo

SOLID STATE IONICS　168　(1-2)　99-109　2004/03

ISSN： 0167-2738
Proton solubility for La2Zr2O7 with a pyrochlore structure doped with a series of alkaline-earth ions Peer-reviewed

T Omata, K Ikeda, R Tokashiki, S Otsuka-Yao-Matsuo

SOLID STATE IONICS　167　(3-4)　389-397　2004/02

DOI： 10.1016/j.ssi.2004.01.015 　

ISSN： 0167-2738
Photocatalytic Behavior of Cerium Titanates, CeTiO4 and CeTi2O6 and Their Composite Powders with SrTiO3 Peer-reviewed

S. Otsuka-Yao-Matsuo, T. Omata, M. Yoshimura

J. Alloys and Compounds　376　262-267　2004
Effect of dopant species on the dissolving site of the protons in La2Zr2O7-doped with alkaline-earth ions Peer-reviewed

T Omata, M Takagi, S Otsuka-Yao-Matsuo

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　150　(11)　E590-E594　2003/11

DOI： 10.1149/1.1617308 　

ISSN： 0013-4651
Photobleaching of methylene blue aqueous solution sensitized by composite powders of titanium oxide with SrTiO3, BaTiO3, and CaTiO3 Peer-reviewed

S Otsuka-Yao-Matsuo, T Omata, S Ueno, M Kita

MATERIALS TRANSACTIONS　44　(10)　2124-2129　2003/10

ISSN： 1345-9678

eISSN： 1347-5320
Photodegradation of methylene blue aqueous solution sensitized by pyrochlore-related kappa-CeZrO4 oxide powder Peer-reviewed

T Omata, K Ono, S Otsuka-Yao-Matsuo

MATERIALS TRANSACTIONS　44　(8)　1620-1623　2003/08

ISSN： 1345-9678

eISSN： 1347-5320
Photocatalytic behavior of titanium oxide-perovskite type Sr(Zr1-xYx)O3-delta composite particles Peer-reviewed

T Omata, S Otsuka-Yao-Matsuo

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY　156　(1-3)　243-248　2003/03

ISSN： 1010-6030
Thermodynamic stability of metastable tetragonal t '-Ce0.5Zr0.5O2 phase in the CeO2-ZrO2 system Peer-reviewed

S Otsuka-Yao-Matsuo, T Yao, T Omata

HIGH TEMPERATURE MATERIALS AND PROCESSES　22　(3-4)　157-164　2003

ISSN： 0334-6455
Electrical conductivity of metastable kappa-CeZrO4 phase possessing ordered arrangement of Ce and Zr ions Peer-reviewed

Noriya Izu, Haruo Kishimoto, Takahisa Omata, Takayuki Yao, Shinya Otsuka-Yao-Matsuo

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS　2　(3-4)　443-448　2001/09

ISSN： 1468-6996
Electrical properties of proton-conducting Ca2+-doped La2Zr2O7 with a pyrochlore-type structure Peer-reviewed

T Omata, S Otsuka-Yao-Matsuo

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　148　(6)　E252-E261　2001/06

ISSN： 0013-4651
Oxygen release behavior of metastable tetragonal t '(meta)-(Ce0.5Zr0.5)O-2 phases prepared by reduction and successive oxidation of t ' phase Peer-reviewed

Noriya Izu, Haruo Kishimoto, Takahisa Omata, Kousuke Ono, Shinya Otsuka-Yao-Matsuo

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS　2　(2)　397-404　2001

DOI： 10.1016/S1468-6996(01)00012-2 　

ISSN： 1468-6996

eISSN： 1878-5514
Infrared Absorption Spectra of High Temperature Proton Conducting Ca2+-doped La2Zr2O7 Peer-reviewed

T. Omata, S. Otsuka-Yao-Matsuo

J. Electrochem. Soc　148　E475-482　2001
Electron trapping center and SnO2-doping mechanism of indium tin oxide Peer-reviewed

T Omata, H Fujiwara, S Otsuka-Yao-Matsuo, N Ono

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING　71　(6)　609-614　2000/12

ISSN： 0947-8396
Crystal structure of metastable K-CeZrO4 phase possessing an ordered arrangement of Ce and Zr ions Peer-reviewed

H Kishimoto, T Omata, S Otsuka-Yao-Matsuo, K Ueda, H Hosono, H Kawazoe

JOURNAL OF ALLOYS AND COMPOUNDS　312　(1-2)　94-103　2000/11

ISSN： 0925-8388
Electrical conductivity of novel tetragonal t '(meta)-(Ce0.5Zr0.5)O-2 phase prepared by reduction and successive oxidation of t ' phase Peer-reviewed

N Izu, H Kishimoto, T Omata, S Otsuka-Yao-Matsuo

JOURNAL OF SOLID STATE CHEMISTRY　151　(2)　253-259　2000/05

ISSN： 0022-4596
Conduction electron generation upon oxygen release of indium tin oxide Peer-reviewed

T Omata, H Fujiwara, S Otsuka-Yao-Matsuo, N Ono

SECOND INTERNATIONAL CONFERENCE ON PROCESSING MATERIALS FOR PROPERTIES　353-356　2000
Vibrational spectroscopic and X-ray diffraction studies of cerium zirconium oxides with Ce/Zr composition ratio=1 prepared by reduction and successive oxidation of t '-(Ce0.5Zr0.5)O-2 phase Peer-reviewed

T Omata, H Kishimoto, S Otsuka-Yao-Matsuo, N Ohtori, N Umesaki

JOURNAL OF SOLID STATE CHEMISTRY　147　(2)　573-583　1999/11

ISSN： 0022-4596
Observation of Electronic Structure in Conduction Band of CaTiO_3

UEDA Kazushige, YANAGI Hiroshi, NOSHIRO Ryuichi, MIZOGUCHI Hiroshi, OMATA Takahisa, UEDA Naoyuki, HOSONO Hideo, KAWAZOE Hiroshi

Journal of the Ceramic Society of Japan　106　(1238)　964-967　1998/10/01
Publisher: The Ceramic Society of Japan
DOI： 10.2109/jcersj.106.964 　

ISSN： 1882-1022

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Electronic structure in the conduction band of CaTiO_3 was examined by the bremsstrahlung isochromat spectroscopy(BIS), X-ray absorption spectroscopy(XAS) and electron energy loss spectroscopy(EELS). Two broad bands were observed at 2 and 7 eV above the Fermi energy in the BIS spectrum. The features of the XAS spectra for Ca L_<2, 3> Ti L_<2, 3> and O K edges were almost the same as those of the EELS spectra, and the XAS spectrum for each element was in reasonable agreement with its partial density of states estimated by an energy band calculation. A trial spectrum was synthesized by the sum of the XAS spectra, and it was found that the feature of the synthesized spectrum is similar to that of the BIS spectrum. From the comparison between XAS and BIS spectra, the two broad bands at 2 and 7 eV in the BIS spectrum were assigned to Ti 3d bands and Ca 4s bands, respectively.
Observation of electronic structure in conduction band of CaTiO3 Peer-reviewed

K Ueda, H Yanagi, R Noshiro, H Mizoguchi, T Omata, N Ueda, H Hosono, H Kawazoe

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　106　(10)　964-967　1998/10

DOI： 10.2109/jcersj.106.964 　

ISSN： 1882-0743

eISSN： 1348-6535
High efficiency-carrier-generation for the oxygen release reaction in indium tin oxide Peer-reviewed

T Omata, H Fujiwara, S Otsuka-Yao-Matsuo, N Ono, H Ikawa

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　37　(7B)　L879-L881　1998/07

ISSN： 0021-4922
Oxygen release behavior of CeZrO4 powders and appearance of new compounds kappa and t Peer-reviewed

S Otsuka-Yao-Matsuo, T Omata, N Izu, H Kishimoto

JOURNAL OF SOLID STATE CHEMISTRY　138　(1)　47-54　1998/06

ISSN： 0022-4596
Properties of transition metal oxides with layered perovskite structure Peer-reviewed

M Takemoto, T Miyajima, K Takayanagi, T Ogawa, H Ikawa, T Omata

SOLID STATE IONICS　108　(1-4)　255-260　1998/05

ISSN： 0167-2738
Oxygen release behaviour of Ce(1-x)ZrxO2 powders and appearance of Ce(8-4y)Zr4yO(14-delta) solid solution in the ZrO2-CeO2-CeO1.5 system Peer-reviewed

N Izu, T Omata, S Otsuka-Yao-Matsuo

JOURNAL OF ALLOYS AND COMPOUNDS　270　(1-2)　107-114　1998/05

ISSN： 0925-8388
Thermodynamic behavior of various phases appearing in the CeZrO4-CeZrO3.5 system and the formation of metastable solid solutions Peer-reviewed

S Otsuka-Yao-Matsuo, N Izu, T Omata, K Ikeda

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　145　(4)　1406-1413　1998/04

ISSN： 0013-4651
In-situ observation of the electrical conductivity upon release and uptake of oxygen in indium tin oxide sinter Peer-reviewed

T Omata, H Fujiwara, S Otsuka-Yao-Matsuo, N Ono

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS　37　(3A)　868-871　1998/03

ISSN： 0021-4922
Water and hydrogen evolution properties and protonic conducting behaviors of Ca2+-doped La2Zr2O7 with a pyrochlore structure Peer-reviewed

T Omata, K Okuda, S Tsugimoto, S Otsuka-Matsuo-Yao

SOLID STATE IONICS　104　(3-4)　249-258　1997/12

ISSN： 0167-2738
New mixed-valence oxides of bismuth: Bi1-xYxO1.5+delta (x=0.4) Peer-reviewed

H Mizoguchi, K Ueda, H Kawazoe, H Hosono, T Omata, S Fujitsu

JOURNAL OF MATERIALS CHEMISTRY　7　(6)　943-946　1997/06

ISSN： 0959-9428
Features of valence band structure of TlAlF4 Peer-reviewed

H. Mizoguchi, T. Omata, H. Kawazoe, S. Fujitsu, H. Hosono, N. Ueda

J. Phys.: Condens. Matter　8　303-312　1997
DC electrorheology of fluid suspending barium titanate in the range of ferroelectric size effects Peer-reviewed

H Ikawa, T Katou, M Satou, T Omata, T Hayashi

FERROELECTRICS　203　(1-4)　241-248　1997

ISSN： 0015-0193
Optical absorption spectra and the nature of conduction carriers of hole-doped Sr1+xLa1-xFeO4 Peer-reviewed

T Omata, H Ikawa, S Fijitsu, N Ueda, H Hosono, H Kawazoe

SOLID STATE COMMUNICATIONS　97　(5)　411-415　1996/02

ISSN： 0038-1098
Preparation and Electrical Properties of La_<2-x>Sr_xMnO_<4+δ> with K_2NiF_4-Structure

OMATA Takahisa, HOSHlNO Susumu, IKAWA Hiroyuki, SASAMOTO Tadashi

Journal of the Ceramic Society of Japan　103　(1204)　1297-1301　1995/12/01
Publisher: The Ceramic Society of Japan
DOI： 10.2109/jcersj.103.1297 　

ISSN： 1882-1022

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Polycrystalline bodies of La_<2-x>Sr_xMn0_<4+δ> (1.0≦x≦2.O) with a K_2NiF_4 structure were prepared by a standard ceramic method. Lattice parameters, electrical conductivity and Seebeck voltage were measured. Fur thermore, optical absorption spectra were recorded to obtain information on changes in the electronic structure in the vicinity of the energy band gap. Changes in lattice parameters were attributed to the disappearance of Jahn Teller distortion of Mn0_6 0ctahedra upon Sr doping. The results suggested that holes doped in the present system were mainly localized on man ganeseions. The temperature dependence of electrical conductivities of all the samples was almost Arrhenius type. Seebeck voltages and optical absorption spectra changed drastically in the composition ranges of 1.0<x< 1.2 and 1.6<x<2.0. It was suggested that the electronic structure near the energy band gap changed drastically in those composition ranges.
Preparation and electrical properties of La2-xSrxMnO4+delta with K2NiF4-structure Peer-reviewed

T Omata, S Hoshino, H Ikawa, T Sasamoto

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　103　(12)　1297-1301　1995/12

DOI： 10.2109/jcersj.103.1297 　

ISSN： 1882-0743

eISSN： 1348-6535
ELECTRONIC TRANSPORT-PROPERTIES OF HOLE-DOPED SR1+XLA1-XCRO4+DELTA Peer-reviewed

T OMATA, T KAWANO, H IKAWA, T SASAMOTO, H HOSONO, H MIZOGUCHI, H KAWAZOE

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　103　(11)　1112-1116　1995/11

DOI： 10.2109/jcersj.103.1112 　

ISSN： 1882-0743

eISSN： 1348-6535
Preparation and electrical properties of La2-xSrxMnO4+δ with K2NIF4-structure

T. Omata, S. Hoshino, H. Ikawa, T. Sasamoto

Yogyo Kyokai Shi/Journal of the Ceramic Society of Japan　103　(12)　1297-1301　1995

ISSN： 0372-7718
Electronic transport properties of hole-doped Sr1+xLa1-xCrO4+δ Peer-reviewed

Takahisa Omata, Takashi Kawano, Hiroyuki Ikawa, Tadashi Sasamoto, Hideo Hosono, Hiroshi Mizoguchi, Hiroshi Kawazoe

Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan　103　(1203)　1112-1116　1995
Publisher: Ceramic Soc of Japan
DOI： 10.2109/jcersj.103.1112 　

ISSN： 0914-5400
K2NiF4型La2-xSrxMnO4+δの合成と電気的性質 Peer-reviewed

小俣孝久, 星野進, 井川博行, 笹本忠

J. Ceram. Soc. Jpn　103　(12)　1297-1301　1995
GENERATION OF ELECTRON CARRIERS IN INSULATING THIN-FILM OF MGIN2O4 SPINEL BY LI+ IMPLANTATION Peer-reviewed

H KAWAZOE, N UEDA, H UNNO, T OMATA, H HOSONO, H TANOUE

JOURNAL OF APPLIED PHYSICS　76　(12)　7935-7941　1994/12

ISSN： 0021-8979
PREPARATION OF CD1-XYXSB2O6 THIN-FILM ON GLASS SUBSTRATE BY RADIO-FREQUENCY SPUTTERING Peer-reviewed

K YANAGAWA, Y OHKI, T OMATA, H HOSONO, N UEDA, H KAWAZOE

APPLIED PHYSICS LETTERS　65　(4)　406-408　1994/07

ISSN： 0003-6951
ELECTRICAL AND MAGNETIC-PROPERTIES OF HOLE-DOPED SR1+XLA1-XFEO4 Peer-reviewed

T OMATA, K UEDA, H HOSONO, M KATADA, N UEDA, H KAWAZOE

PHYSICAL REVIEW B　49　(15)　10194-10199　1994/04

ISSN： 0163-1829
ELECTRONIC-STRUCTURE OF HOLE-DOPED SR1+XLA1-XFEO4 STUDIED BY UPS AND XAS Peer-reviewed

T OMATA, K UEDA, H HOSONO, T MIYAZAKI, S HASEGAWA, N UEDA, H KAWAZOE

PHYSICAL REVIEW B　49　(15)　10200-10205　1994/04

ISSN： 0163-1829
NEW OXIDE PHASE CD2(1-X)Y2XSB2O7 PYROCHLORE WITH A WIDE-BAND GAP AND HIGH ELECTRICAL-CONDUCTIVITY Peer-reviewed

K YANAGAWA, Y OHKI, T OMATA, H HOSONO, N UEDA, H KAWAZOE

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS　33　(2B)　L238-L240　1994/02

ISSN： 0021-4922
NEW ULTRAVIOLET-TRANSPORT ELECTROCONDUCTIVE OXIDE, ZNGA2O4 SPINEL Peer-reviewed

T OMATA, N UEDA, K UEDA, H KAWAZOE

APPLIED PHYSICS LETTERS　64　(9)　1077-1078　1994/02

ISSN： 0003-6951
NEW OXIDE PHASE CD1-XYXSB2O6 WITH A WIDE-BAND GAP AND HIGH ELECTRICAL-CONDUCTIVITY Peer-reviewed

K YANAGAWA, Y OHKI, N UEDA, T OMATA, T HASHIMOTO, H KAWAZOE

APPLIED PHYSICS LETTERS　63　(24)　3335-3337　1993/12

ISSN： 0003-6951
PREPARATION OF OXYGEN EXCESS SRLAFEO4+DELTA AND ITS ELECTRICAL AND MAGNETIC-PROPERTIES Peer-reviewed

T OMATA, K UEDA, N UEDA, M KATADA, S FUJITSU, T HASHIMOTO, H KAWAZOE

SOLID STATE COMMUNICATIONS　88　(10)　807-811　1993/12

ISSN： 0038-1098
PREPARATION OF MGIN2O4-X THIN-FILMS ON GLASS SUBSTRATE BY RF-SPUTTERING International-journal Peer-reviewed

H UNNO, N HIKUMA, T OMATA, N UEDA, T HASHIMOTO, H KAWAZOE

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　32　(9A)　L1260-L1262　1993/09

ISSN： 0021-4922
NEW OXIDE PHASE WITH WIDE BAND-GAP AND HIGH ELECTROCONDUCTIVITY CDGA2O4 SPINEL International-journal Peer-reviewed

T OMATA, N UEDA, N HIKUMA, K UEDA, H MIZOGUCHI, T HASHIMOTO, H KAWAZOE

APPLIED PHYSICS LETTERS　62　(5)　499-500　1993/02

ISSN： 0003-6951
NEW OXIDE PHASE WITH WIDE BAND-GAP AND HIGH ELECTROCONDUCTIVITY, MGIN2O4 International-journal Peer-reviewed

N UEDA, T OMATA, N HIKUMA, K UEDA, H MIZOGUCHI, T HASHIMOTO, H KAWAZOE

APPLIED PHYSICS LETTERS　61　(16)　1954-1955　1992/10

ISSN： 0003-6951

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Misc. 36

Effect of WO₃ addition to phosphate glasses on thermal stability and proton mobility

SHARMA Aman, 鈴木一誓, 石山智大, 小俣孝久

日本セラミックス協会年会講演予稿集(Web)　2024　2024
Structure and Proton conductive Properties of Phosphate Glasses Containing Al and Si

山田裕也, 藤岡正弥, 小野円佳, 西井準治, 永島裕樹, 石山智大, 小俣孝久

日本セラミックス協会秋季シンポジウム講演予稿集(Web)　35th　2022
New solid-like polymerized phosphoric acid; protonic conductivity and thermal stability at intermediate temperatures of anhydrous silicophosphoric and germanophosphoric acid glasses

小俣孝久, SHARMA Aman, 鈴木一誓, 石山智大, 西井準治

固体イオニクス討論会講演要旨集　48th　2022
Measurement of proton partial conductivity at intermediate temperatures of H_xWO₃ using proton conducting phosphate glass as an electron-blocking electrode.

松尾蘭太郎, 山田将斗, 小俣孝久, 石山智大, 山口拓哉

日本セラミックス協会秋季シンポジウム講演予稿集(Web)　35th　2022
Dependence of proton conductivity on Si and Al contents in phosphate glasses

山田裕也, 永島裕樹, 石山智大, 藤岡正弥, 小野円佳, 小俣孝久, 西井準治

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　83rd　2022

ISSN： 2758-4704
中温作動電気化学デバイスのためのプロトン伝導性リン酸塩ガラス電解質

石山智大, 小俣孝久

セラミックス　57　715-719　2022
Enhancing the proton mobility and thermal stability of phosphate glasses by additional GeO₂

小俣孝久, SHARMA Aman, 鈴木一誓, 石山智大, 西井準治

固体イオニクス討論会講演要旨集　47th (CD-ROM)　2021
特集エネルギー・環境問題を解決する新材料・新技術巻頭言

小俣孝久

金属　90　(10)　3-3　2020/10

ISSN： 0368-6337
Machine learning approach for understanding the effect of respective oxides on proton mobility in phosphate glasses

小俣孝久, SHARMA Aman, 鈴木一誓, 石山智大, 西井準治, 山下俊晴, 川副博司

固体イオニクス討論会講演要旨集　46th (CD-ROM)　2020
Sputtering deposition of n-type SnS thin films

鈴木一誓, 川西咲子, BAUERS Sage, ZAKUTAYEV Andriy, 柴田浩幸, KIM Minesok, 柳博, 小俣孝久

資源・素材(Web)　2020　2020
Effect of Halogen on Solution Growth of SnS Single Crystals

川西咲子, 鈴木一誓, 小俣孝久, 柴田浩幸

結晶成長国内会議予稿集(CD-ROM)　49th　2020

ISSN： 0385-6275
Fabrication of n-type SnS thin films by sputtering deposition

鈴木一誓, 川西咲子, BAUERS Sage, ZAKUTAYEV Andriy, 柴田浩幸, KIM Minesok, 柳博, 小俣孝久

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　81st　2020
Fabrication of pn homojunction of SnS and its photovoltaic properties

川西咲子, 鈴木一誓, BAUERS Sage, ZAKUTAYEV Andriy, 柴田浩幸, 柳博, 小俣孝久

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　81st　2020
ガラス構造緩和によるリン酸塩ガラスのプロトン伝導度変化

石山智大, 山口拓哉, 岸本治夫, DEVELOS-BAGARINAO Katherine, 山地克彦, 小俣孝久

固体イオニクス討論会講演要旨集　45th　2019
プロトン伝導性リン酸塩ガラスにおけるガラス構造とプロトン溶解状態の高温その場分析

石山智大, 山口拓哉, 岸本治夫, BAGARINAO Katherine Develos, 山地克彦, 小俣孝久

電気化学秋季大会講演要旨集(CD-ROM)　2019　2019
中温域で高いプロトン伝導度を発現するリン酸塩ガラス

山口拓哉, 佃諭志, 小俣孝久, 石山智大, 西井準治, 山下俊晴, 川副博司

日本セラミックス協会年会講演予稿集(CD-ROM)　2018　2018
プロトン伝導性リン酸塩ガラス・融液のプロトン移動度

小俣孝久, 山口拓哉, 佃諭志, 石山智大, 西井準治, 山下俊晴, 川副博司

固体イオニクス討論会講演要旨集　44th　2018
プロトン伝導性ガラス電解質のプレス加工による薄板化

田代真敬, 鈴木一誓, 山口拓哉, 石山智大, 西井準治, 山下俊晴, 川副博司, 小俣孝久

東北大学多元物質科学研究所研究発表会講演予稿集　18th　2018
プロトン伝導性リン酸塩ガラスのプレス加工による薄板化

田代真敬, 鈴木一誓, 小俣孝久, 山口拓哉, 石山智大, 西井準治, 山下俊晴, 川副博司

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)　31st　2018
プロトン伝導性リン酸塩ガラスのプロトンキャリアの移動度

山口拓哉, 佃諭志, 小俣孝久, 片岡拓也, 斎藤泰久, 桑原泰隆, 山下弘巳, 石山智大, 西井準治, 山下俊晴, 川副博司

日本セラミックス協会年会講演予稿集(CD-ROM)　2018　2018
“研究開発の俯瞰報告書研究開発の新しい動向（2017年）照明・ディスプレイ（量子ドット発光材料）

小俣孝久

国立研究開発法人科学技術振興機構研究開発戦略センター　2017
中温域で高いプロトン移動度を発現するリン酸塩ガラス

山口拓哉, 片岡拓也, 斎藤泰久, 西井準治, 山下俊晴, 川副博司, 石山智大, 山地克彦, 小俣孝久

固体イオニクス討論会講演要旨集　42nd　208‐209　2016/12/05
Design of Oxide Energy Materials and Development of Their Synthesis Processes

T. Omata

Kozan　69　(10)　22-30　2016/12

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1461
Capability for developing new materials in Japan; the areas where we should reinforce.

T. Omata

MMIJ Quarterly　1　(4)　42-44　2016/10
Publisher: 資源・素材学会
ISSN： 2189-941X

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1462
アルカリ‐プロトン置換したリン酸塩ガラスの伝導特性と熱的特性

木下拓也, 宮崎篤, 藤岡正弥, 海住英生, 西井準治, 山口拓哉, 小俣孝久

日本セラミックス協会年会講演予稿集(CD-ROM)　2016　ROMBUNNO.3K01　2016/03/01
Ternary and Quaternary Wurtzite-type Oxide Semiconductors; New Materials and Their Properties

T. Omata

OXIDE-BASED MATERIALS AND DEVICES VI　9364　2015

DOI： 10.1117/12.2175570 　

ISSN： 0277-786X
酸化物ガラスへの高濃度プロトンキャリアの電気化学的注入法;高温アルカリ-プロトン置換法

石山智大, 西井準治, 山下俊晴, 川副博司, 小俣孝久

資源・素材学会春季大会(Web)　2014　2014
中温域で安定な新規プロトン伝導性リン酸塩ガラス

石山智大, 鈴木翔悟, 西井準治, 山下俊晴, 川副博司, 小俣孝久

電気化学秋季大会講演要旨集　2013　142　2013/09/27
酸化物ガラスへの高濃度プロトンキャリアの電気化学的注入法;高温アルカリ‐プロトン置換法

石山智大, 鈴木翔悟, 西井準治, 山下俊晴, 川副博司, 小俣孝久

電気化学秋季大会講演要旨集　2013　142　2013/09/27
中温作動型燃料電池に適したプロトン伝導体の設計指針

小俣孝久, 石山智大, 鈴木翔悟, 西井準治, 山下俊晴, 川副博司

電気化学秋季大会講演要旨集　2013　141　2013/09/27
Non-aqueous solution route to compound and metallic nanocrystals

Molten salts　52　(2)　56-62　2009
Publisher: 電気化学会溶融塩委員会
ISSN： 0916-1589
Synthesis of Core-shell-type Composite Nanocrystals and Their Development to Advanced Ceramics

OMATA Takahisa

Ceramics Japan　42　(2)　99-103　2007/02/01
Publisher: 日本セラミックス協会
ISSN： 0009-031X
Structures and Appearance Factors of Metastable Phases Appeared at CeO_2:ZrO_2=1:1 Composition

KISHIMOTO Haruo, OMATA Takahisa, OTSUKA-YAO-MATSUO Shinya

(34)　64-65　1999/05/27

ISSN： 0910-2205
Electronic structure and electrical conductivity of Sr_<1+x>La_<1-x>CrO_4

Omata T., Kawano T., Ikawa H., Hosono H., Mizoguchi H., Kawazoe H.

Abstracts of the meeting of the Physical Society of Japan. Sectional meeting　1995　(3)　574-574　1995/09/12
Publisher: The Physical Society of Japan (JPS)
29a-PS-33 Electronic structure and magnetic and electrical properties of Sr_<1+x>La_<1-x>FeO_4 I

Omata T, Ueda K, Hosono H, Katada M, Ueda N, Kawazoe H

Abstracts of the meeting of the Physical Society of Japan. Annual meeting　49　(3)　91-91　1994/03/16
Publisher: The Physical Society of Japan (JPS)
29a-PS-34 Electronic structure and magnetic and electrical properties of Sr_<1+x>La_<1-x>FeO_4 II

Omata T, Ueda K, Hosono H, Miyazaki T, Hasegawa S, Ueda N, Kawazoe H

Abstracts of the meeting of the Physical Society of Japan. Annual meeting　49　(3)　92-92　1994/03/16
Publisher: The Physical Society of Japan (JPS)

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Books and Other Publications 3

ベーシック無機材料科学

辰巳砂, 昌弘, 今中, 信人

化学同人　2021/02

ISBN: 9784759820249
ディスプレイ・照明・バイオマーカーから太陽電池までデバイス応用に向けた量子ドット材料の最新技術動向

小俣孝久

情報機構　2017/06
Technologies to improve conversion efficiency of solar cells by wavelength conversion from near UV to NIR and increasing light absorption

T. Omata

S&T出版　2016/01

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880

Presentations 209

固体電解質のイオンダイナミクスの多面的な解析 International-coauthorship

村上美和, 嶺重温, 小俣孝久, Arunkumar Dorai, 竹腰清乃理

電気化学会第92回大会, 東京農工大学小金井キャンパス，東京都　2025/03/18
水素を溶解した電子伝導性酸化物MgIn2O4中のプロトン伝導性 International-coauthorship

山﨑智之, 工藤咲季, Rafael Costa Amaral, Bae Soungmin, 熊谷悠, 小俣孝久

電気化学会第92回大会, 東京農工大学小金井キャンパス，東京都　2025/03/18
Biドープによるn型SnSの作製

川西咲子, 八木開斗, 野上大一, 鈴木一誓, 小俣孝久

第72回応用物理学会春期学術講演会, 東京理科大学野田キャンパス，野田市　2025/03/14
ZnTeをベースとした非Cd系II–VI化合物半導体量子ドット蛍光体 Invited

小俣孝久

第72回応用物理学会春期学術講演会, 東京理科大学野田キャンパス，野田市　2025/03/14
陽イオン交換によるウルツ鉱型関連構造のナローギャップ酸化物半導体Cu2ZnSiO4の合成およびCu2Zn(Ge,Si)O4混晶系の開発

喜多正雄, 鈴木一誓, 小俣孝久

日本セラミックス協会2025年年会, 静岡大学浜松キャンパス，浜松市　2025/03/05
過剰プロトン溶解による酸水酸化インジウムInO(OH)のプロトンー電子混合伝導性の発現 International-coauthorship

山﨑智之, ドライアルンクマール, 小俣孝久

第50回固体イオニクス討論会　2024/12/09
Evaluation of ion conduction mechanism in a high fluoride conducting solid electrolyte International-coauthorship

Arunkumar Dorai, Miwa Murakami, Atsushi Mineshige, Reiji Takekawa, Kiyonori Takegoshi, Takahisa Omata, Junichi Kawamura

2024/12/09
固体イオン交換における新たな平衡場を活用した酸化物半導体の合成

鈴木一誓, 鷲津加子, 喜多正雄, 小俣孝久

第50回固体イオニクス討論会　2024/12/11
NbドープしたTiO2のプロトン電子混合伝導性

白岩拓真, 山崎智之, 小俣孝久

第50回固体イオニクス討論会　2024/12/11
LPEによるSnSホモ接合の作製

宮井隆行, 鈴木一誓, 長谷川将克, 小俣孝久, 川西咲子

第53回結晶成長国内会議（JCCG-53）　2024/11/18
The orientations and J-V characteristics of a SnS homojunction solar cell fabricated by LPE International-presentation

T. Miyai, I. Suzuki, M. Hasegawa, T. Omata, S. Kawanishi

35th International Photovoltaic Science and Engineering Conference (PVSEC-35), Numazu, Japan　2024/11/10
Design and Explore New Materials: What to consider and how to approach the discovery of new materials International-presentation Invited

T. Omata

2024 23rd Korea Japan Students’ Symposium　2024/10/31
Mixed Protonic and Electronic Conduction in n-type Oxide Semiconductor MgIn2O4 under Hydrogen Atmosphere International-presentation

T. Yamasaki, S. Kudo, T. Omata

2024 Pacific Rim Meeting on Electrochemical and Solid State Science (PRiME 2024) , Honolulu, US　2024/10/06
Improving the Stability and Transport Properties of a High Concentration of Protons in Phosphate Glass at Intermediate Temperatures International-presentation Invited

T. Omata, T. Ishiyama, J. Nishii

2024 Pacific Rim Meeting on Electrochemical and Solid State Science (PRiME 2024) , Honolulu, US　2024/10/06
Mixed protonic and electronic conduction in n-type oxide semiconductors International-presentation Invited

T. Omata

4th ELSICS (Energy Landscapes and Structure in Ion Conducting Solids) Workshop and Bunsen-Colloquium, Marburg, Germany　2024/09/30
化学量論組成からのずれに起因する内因性欠陥がSnS薄膜の物性に与える影響

野上大一, 茂田井大輝, 鈴木一誓, 小俣孝久

第85回応用物理学会秋季学術講演会　2024/09/16
固体イオン交換を活用した酸化物固溶体の合成：(Na,Ag)GaO2の例

鈴木一誓, 喜多正雄, 小俣孝久

第85回応用物理学会秋季学術講演会　2024/09/16
30NaO1/2-20VO5/2-50PO5/2ガラス中のNaイオンのプロトンへの置換による電子伝導性の抑制 International-coauthorship

アマンシャルマ, 鈴木一誓, 豊岡慶, 石山智大, 西井準治, 小俣孝久

日本セラミックス協会第37回秋季シンポジウム　2024/09/10
プロトン伝導性リン酸塩ガラスの熱的・電気的性質へのGeO2添加の効果

豊岡慶, 石山智大, 小俣孝久

日本セラミックス協会第37回秋季シンポジウム　2024/09/10
透明導電性酸化物ITOへの水素の溶解とプロトン伝導性

松本真志, 白岩拓真, 山﨑智之, 小俣孝久

日本セラミックス協会第37回秋季シンポジウム（優秀発表賞）　2024/09/10
Fluoride ion conduction mechanism Ba1-xSnxF4 solid electrolyte studied using 19F PFG-NMR International-presentation

D. Arunkumar, M. Murakami, A. Mineshige, R. Takekawa, K. Takegoshi, T. Omata, J. Kawamura

24th International Conference on Solid State Ionics, London, UK　2024/07/15
Cermet-supported type phosphate glass electrolyte electrochemical cell for energy conversion devices International-presentation

T. Ishiyama, H. Arai, H. Nagashima, H. Miyamura, K. Koga, A. Sharma, T. Yamaguchi, T. Omata

24th International Conference on Solid State Ionics, London, UK　2024/07/15
Mixed protonic and electronic conductivity of Nb-doped TiO2 under hydrogen atmosphere International-presentation

T. Shiraiwa, T. Yamasaki, T. Omata

24th International Conference on Solid State Ionics, London, UK　2024/07/15
Suppression of electronic conduction by local structural change around vanadium ions induced by replacing sodium ions with protons in vanadophosphate glass International-presentation

T. Omata, A. Sharma, I. Suzuki, K. Toyooka, T. Ishiyama, J. Nishii

24th International Conference on Solid State Ionics, London, UK　2024/07/15
金属ターゲットと硫黄プラズマを用いた反応性スパッタリングによる CuxS・ZnS・SnS・WS2薄膜の作製

茂田井大輝, 野上大一, 鈴木一誓, 小俣孝久

2024年度資源・素材学会東北支部春季大会（優秀発表賞）　2024/06/14
水素雰囲気下におけるNbドープしたTiO2のプロトン電子混合伝導性

白岩拓真, 山崎智之, 小俣孝久

2024年度資源・素材学会東北支部春季大会　2024/06/14
Application of statistical approaches to proton-conducting phosphate glasses: Study of the effect of oxide components on proton mobility and thermal stability International-presentation Invited

T. Omata

MRS/ACerS Joint AI and ML Virtual Workshop, On-line　2024/05/26
酸化物中のプロトン輸送の促進に関わる基礎化学 Invited

小俣孝久

東北大学 SOFC/SOEC実装支援研究センター 2024年度第１回現地オープンサイエンスイベント　2024/04/16
SnSホモ接合太陽電池における短絡電流密度の向上

宮井隆行, 川西咲子, 長谷川将克, 鈴木一誓, 小俣孝久, 柏谷悦章

第71回応用物理学会春期学術講演会（東京都市大学世田谷キャンパス）　2024/03/22
SnターゲットとSプラズマの反応性スパッタリングによるSnS薄膜の作製

茂田井大輝, 野上大一, 鈴木一誓, 小俣孝久

第71回応用物理学会春期学術講演会（東京都市大学世田谷キャンパス）　2024/03/22
硫黄プラズマを援用したスパッタリングによる化学量論組成SnS薄膜の作製

野上大一, 鈴木一誓, 小俣孝久

第71回応用物理学会春期学術講演会（東京都市大学世田谷キャンパス）　2024/03/22
硫黄プラズマを用いた反応性スパッタリングによる種々の硫化物薄膜の作製

鈴木一誓, 茂田井大輝, 野上大一, 小俣孝久

第71回応用物理学会春期学術講演会（東京都市大学世田谷キャンパス）　2024/03/22
スプレーCVD法により成膜したCu3VO4薄膜の光学的・電気的特性

喜多正雄, 鈴木一誓, 小俣孝久

日本セラミックス協会2024年年会（熊本大学黒髪キャンパス）　2024/03/14
β-LiGaO2のイオン交換による太陽電池材料β-CuGaO2の合成

鈴木一誓, 鷲津加子, 小俣孝久, 喜多正雄

日本セラミックス協会2024年年会（熊本大学黒髪キャンパス）　2024/03/14
NbドープしたTiO2に水素雰囲気下で溶解したプロトンの伝導性と化学環境

白岩拓真, 山崎智之, 小俣孝久

日本セラミックス協会2024年年会（熊本大学黒髪キャンパス）　2024/03/14
リン酸塩ガラスの熱安定性とプロトン伝導性に及ぼすWO3添加の効果

アマンシャルマ, 鈴木一誓, 石山智大, 小俣孝久

日本セラミックス協会2024年年会（熊本大学黒髪キャンパス）　2024/03/14
Phosphate and phosphoric acid glasses: Promising materials for electrolytes in next-gen fuel cells and electrolysis cells operating around 300℃ International-presentation Invited

T. Omata

International Seminar on "Emerging Materials for Energy Application", organized by PG & Research Department of Physics, Mannar Thirumalai Naicker College, Madurai, Tamil Nadu, India on 24th Feb 2024　2024/02/24
In-situ visualization of Mn2+ ion dissolution in Zn-MnO2 battery International-presentation International-coauthorship

H. Nithya, D. Arunkumar, M. Okada, R. Takekawa, M. Murakami, T. Omata, J. Kawamura

18th Asian Conference on Solid State Ionics, Chennai, India　2024/02/19
Fluoride ion dynamics of high conducting electrolytes studied using NMR International-presentation International-coauthorship Invited

D. Arunkumar, H. Nithya, T. Omata, J. Kawamura

18th Asian Conference on Solid State Ionics, Chennai, India　2024/02/19
Mixed protonic and electronic conduction in MgIn2O4 under hydrogen atmosphere and its proton partial conductivity International-presentation

S. Kudo, T. Omata

18th Asian Conference on Solid State Ionics, Chennai, India　2024/02/19
Proton conducting phosphate glass: A method to inject highly concentrated proton carriers achieving high proton conductivity at intermediate temperatures International-presentation Invited

T. Omata, T. Ishiyama, J. Nishii

2024/02/19
Phosphate and phosphoric acid glasses as electrolytes in electrochemical cells operating around 300 °C International-presentation Invited

T. Omata

2023 Tohoku-NTUT Joint Symposium（Taipei, TAIWAN）　2023/12/11
酸化物とイオン結晶間の固相ー固相／固相ー液相イオン交換反応による準安定化合物の合成

鈴木一誓, 小俣孝久

第49回固体イオニクス討論会（北海道大学）　2023/11/15
プロトン伝導性酸化物中のO−H結合の強度を律する機構

小俣孝久

第49回固体イオニクス討論会（北海道大学）　2023/11/15
Controlling proton transport in phosphate glasses International-presentation

T. Omata

3rd ELSICS (Energy Landscapes and Structure in Ion Conducting Solids) Workshop and Bunsen-Colloquium（Ulm, Germany）　2023/10/04
Suppression of proton migration by SiO6 in phosphate glasses and its mitigation by AlO6 substitution International-presentation

T. Ishiyama, Y. Yamada, H. Nagashima, I. Suzuki, M. Fujioka, M. Ono, T. Omata, J. Nishii

21st International conference on solid state proton conductors（Fukuoka, Japan）　2023/09/17
Enhancing proton migration in phosphate glasses by addition of WO3 International-presentation

T. Omata, A. Sharma, I. Suzuki, T. Ishiyama

21st International conference on solid state proton conductors（Fukuoka, Japan）　2023/09/17
q分解EELS を用いたβ-CuGaO2の電子構造の研究

大澤優太, 斎藤興也, 佐藤庸平, 寺内正己, 鈴木一誓, 小俣孝久

日本物理学会第78回年次大会（東北大学青葉山、川内キャンパス）　2023/09/16
副産物の有効利用に向けた機能材料開発；電気化学的陽イオン置換法によるヒ素を含有する準安定な機能性酸化物半導体の合成

鈴木一誓, 小俣孝久, 渡邉寛人, 浅野聡

資源・素材2023（愛媛大学）　2023/09/12
角度分解光電子分光によるSnS-SnSe 混晶半導体の有効質量の直接評価

鈴木一誓, リンタクシン, 川西咲子, 田中清尚, 野瀬嘉太郎, 小俣孝久, 田中慎一郎

日本セラミックス協会第36回秋季シンポジウム（京都工芸繊維大学）　2023/09/06
水素雰囲気下におけるNbドープしたTiO2のプロトン-電子混合伝導性

白岩拓真, 山﨑智之, 小俣孝久

日本セラミックス協会第36回秋季シンポジウム（京都工芸繊維大学）　2023/09/06
MgIn2O4の水素雰囲気におけるプロトン-電子混合伝導性（FCDIC優秀発表賞）

工藤咲季, 鈴木一誓, 山﨑智之, 小俣孝久

日本セラミックス協会第36回秋季シンポジウム（京都工芸繊維大学）　2023/09/06
Phosphate and phosphoric acid glasses: Promising electrolytes for next-generation fuel and electrolysis cells operating at around 300 °C. International-presentation Invited

T. Omata, T. Ishiyama, J. Nishii

2023 Annual Meeting of Society of Glass Technology（Cambridge, UK）　2023/09/04
TiO2の水素雰囲気下中温域におけるプロトン－電子混合伝導性

白岩拓真, 小俣孝久

第17回固体イオニクスセミナー（山形蔵王）　2023/08/07
MgIn2O4の水素雰囲気における高温でのプロトン-電子混合伝導性（優秀発表賞）

工藤咲季, 小俣孝久

第17回固体イオニクスセミナー（山形蔵王）　2023/08/07
中温域でプロトン・電子混合伝導性を発現する材料HxWO3の混合伝導性

松尾蘭太郎, 小俣孝久, 石山智大, 山口拓哉

第17回固体イオニクスセミナー（山形蔵王）　2023/08/07
PGSカソードを用いたスパッタリング法によるSnS薄膜の作製

野上大一, 鈴木一誓, 小俣孝久

第70回応用物理学会春期学術講演会（上智大学四谷キャンパス）　2023/03/15
三元系ウルツ鉱型酸化物半導体におけるイオン交換反応

鈴木一誓, 小俣孝久

第70回応用物理学会春期学術講演会（上智大学四谷キャンパス）　2023/03/15
Promotion of proton migration by controlling phosphate flamework in proton conducting phosphate glasses Invited

Takahisa Omata

2023/03/09
Nbドープした TiO2の水素雰囲気下での電気伝導度の増大とその起源

白岩拓真, 鈴木一誓, 小俣孝久

日本セラミックス協会2023年年会（神奈川大学みなとみらいキャンパス）　2023/03/08
三元系ウルツ鉱型酸化物とイオン結晶のイオン交換反応

鈴木一誓, 小俣孝久

日本セラミックス協会2023年年会（神奈川大学みなとみらいキャンパス）　2023/03/08
新たな擬固体リン酸ポリマー無水シリコリン酸・ゲルマノリン酸ガラスのプロトン伝導性と中温域での安定性

小俣孝久, Aman Sharma, 鈴木一誓, 石山智大, 西井準治

第48回固体イオニクス討論会（仙台）　2022/12/06
N-type SnS and its application to homojunction solar cells

I. Suzuki, S. Kawanishi, S. R. Bauers, A. Zakutayev, M. Kim, H. Yanagi, T. Omata

33rd. the International Photovoltaic Science and Engineering Conference (PVSEC-33)　2022/11/16
偏光依存ARPESを用いたSnS価電子帯の電子構造の解析

鈴木一誓, 川西咲子, 田中清尚, 田中慎一郎, 小俣孝久

2022年応用物理学会秋季学術講演会（仙台）　2022/09/21
リン酸塩ガラスのプロトン伝導度のSi，Al含有量依存性

山田裕也, 永島裕樹, 石山智大, 藤岡正弥, 小野円佳, 小俣孝久, 西井準治

2022年応用物理学会秋季学術講演会（仙台）　2022/09/21
角度分解光電子分光によるSnS価電子帯の原子軌道の同定

鈴木一誓, 川西咲子, 田中清尚, 田中慎一郎, 小俣孝久

日本セラミックス協会第35回秋季シンポジウム（徳島）　2022/09/15
n型電子伝導性酸化物MgIn2O4の高温での電気伝導性

工藤咲季, 鈴木一誓, 小俣孝久

日本セラミックス協会第35回秋季シンポジウム（徳島）　2022/09/14
プロトン伝導性リン酸塩ガラスを電子ブロッキング電極とした中温域でのHxWO3のプロトン伝導度測定

松尾蘭太郎, 石山智大, 山口拓哉, 小俣孝久

日本セラミックス協会第35回秋季シンポジウム（徳島）　2022/09/16
AlおよびSiを含有するリン酸塩ガラスの構造とプロトン伝導特性

山田裕也, 永島裕樹, 石山智大, 藤岡正弥, 小野円佳, 小俣孝久, 西井準治

日本セラミックス協会第35回秋季シンポジウム（徳島）　2022/09/16
Experimental study of the effect of WO3 on proton mobility and thermal stability of proton conducting phosphate glasses

A. Sharma, I. Suzuki, T. Omata

17th Asian Conference on Solid State Ionics (ACSSI-2020)　2022/09/14
60分でわかる量子ドット蛍光体；その基礎から応用

小俣孝久

SID日本支部第17回サマーセミナー（オンライン）　2022/08/25
（優秀発表賞）

2022/08/08
Proton conductivity and thermal stability of anhydrous silico- and germano-phosphoric acid glasses Invited

T. Omata, A. Sharma, I. Suzuki, T. Ishiyama, J. Nishii

23rd International Conference on Solid State Ionics (SSI-23)　2022/07/22
時代を切り拓いてきたのはいつも新しい材料だった－エネルギー・資源・環境問題を解決する切り札は・・・－ Invited

小俣孝久

東北大学グリーンゴールズパートナー2022年第4回研究会　2022/05/19
偏光を用いたバンド起源の解明：SnSの角度分解光電子分光

田中慎一郎, 鈴木一誓, 川西咲子, 小俣孝久, 田中清尚

第35回日本放射光学会年会・放射光科学合同シンポジウム(オンライン）　2022/01/09
GeO2添加によるリン酸塩ガラスのプロトン移動度と熱安定性の向上

小俣孝久, Aman Sharma, 鈴木一誓, 石山智大, 西井準治

第47回固体イオニクス討論会（徳島）　2021/12/08
SnS 単結晶/MoO3 界面の電子構造と太陽電池への応用

鈴木一誓, 川西咲子, リンタクシン, 小俣孝久, Binxiang Huang, Andreas Klein

日本セラミックス協会第41回電子材料研究討論会(オンライン)　2021/11/04
Technique for evaluating isotope exchange reaction coefficients on proton-conducting phosphate glass surfaces by Raman spectroscopy

T. Ishiyama, T. Yamaguchi, J. Nishii, T. Yamashita, H. Kawazoe, T. Omata

International workshop on solid state proton conductors (SSPC-20), Online Conferenc　2021/09/30
Understanding the effect of oxide components on proton mobility in phosphate glasses; statistical analysis and experimental studies

T. Omata, I. Suzuki, A. Sharma, T. Kinoshita, T. Ishiyama, S. Kohara, T. Yamashita, H. Kawazoe, T. Fang, Y. Ren, M. Fujioka, M. Ono, G. Zhao, J. Nishii

International workshop on solid state proton conductors (SSPC-20), Online Conference　2021/10/01
Zn(Te1-xSex)/ZnSe量子ドットの合成と光学特性

佃諭志, 喜多正雄, 小俣孝久

第82回応用物理学会秋季学術講演会(オンライン）　2021/09/10
ARPESによるSnSの価電子帯の原子軌道の同定

鈴木一誓, 川西咲子, 小俣孝久, 田中慎一郎

第82回応用物理学会秋季学術講演会(オンライン）　2021/09/12
ウルツ鉱型関連構造のナローギャップ酸化物半導 Cu2ZnGeO4 の高温における相転移

喜多正雄, 和田憲幸, 鈴木一誓, 小俣孝久

日本セラミックス協会第34回秋季シンポジウム（オンライン）　2021/09/02
ビス（トリメチルシリル）スルフィドおよびテルリドを用いた Zn(Te1-xSx )混晶量子ドットの合成とその光学特性

松尾蘭太郎, 佃諭志, 小俣孝久

日本セラミックス協会第34回秋季シンポジウム（オンライン）　2021/09/01

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優秀発表賞受賞
近赤外バイオイメージング Ag2S 量子ドット蛍光体の高輝度化

佃諭志, 牧野泰, 喜多正雄, 小俣孝久

日本セラミックス協会第34回秋季シンポジウム（オンライン）　2021/09/01
ARPES によるSnS の価電子帯の電子構造の解明

鈴木一誓, 川西咲子, 小俣孝久, 田中慎一郎

日本セラミックス協会第34回秋季シンポジウム（オンライン）　2021/09/01
大きなバンド屈曲を示す n型 SnS/MoO3 接合の太陽電池への応用

リンタクシン, 鈴木一誓, 川西咲子, 小俣孝久

日本セラミックス協会第34回秋季シンポジウム（オンライン）　2021/09/01
β-CuGaO2薄膜の作製と特性評価

鈴木惇市, 鈴井一誓, 小俣孝久

日本セラミックス協会第34回秋季シンポジウム（オンライン）　2021/09/01
コロイダル量子ドットとその応用；蛍光体を中心に Invited

小俣孝久

産総研FIoTコンソーシアム機能性フレキシブルとインクジェット技術分科会（オンライン）　2021/07/30
Ce3+-Tb3+共添加ペロブスカイト型LaLuO3 中のCe3+からTb3+へのエネルギー移動

永島彰一郎, 植田和茂, 小俣孝久

日本セラミックス協会 2021年年会（オンライン）　2021/03/24
パルスレーザー堆積法による化学量論組成のβ-NaGaO2薄膜作製

鈴木惇市, 鈴木一誓, 小俣孝久

日本セラミックス協会 2021年年会（オンライン）　2021/03/25
フェルミ準位がとりうるエネルギー範囲からみたSnS 太陽電池のポテンシャル

鈴木一誓, 川西咲子, リンタクシン, 小俣孝久, Binxiang Huang, Andreas Klein

日本セラミックス協会 2021年年会（オンライン）　2021/03/25
Zn(Te1-xSex)/ZnS及びZn(Te1-xSex)/ZnSe量子ドットの合成と光学特性

佃諭志, 喜多正雄, 小俣孝久

日本セラミックス協会 2021年年会（オンライン）　2021/03/23
SnS太陽電池におけるVOC > 0.7 Vの可能性〜フェルミ準位の制御性の観点から〜

鈴木一誓, 川西咲子, リンタクシン, 小俣孝久, Binxiang Huang, Andreas Klein

第68回応用物理学会春季学術講演会(オンライン　2021/03/16
Synthesis and optical properties of Zn(Te,S) alloy quantum dots promising as a red phosphor

S. Tsukuda, H. Inayoshi, M. Kita, T. Omata

11th International Conference on Quantum Dots (QD2020)　2020/12/10
機械学習を利用したリン酸塩ガラス中の各種成分のプロトン伝導性に及ぼす効果の理解

小俣孝久, 鈴木一誓, 石山智大, 西井準治, 山下俊晴, 川副博司

第46回固体イオニクス討論会（オンライン）　2020/12/09
Synthesis and application of colloidal alloy quantum dots

Satoshi Tsukuda, Takahisa Omata

2020 IMRAM-NTUT Online Joint Symposium　2020/11/30
n型SnS の作製とホモ接合太陽電池への展開

鈴木一誓, 川⻄咲子, Bauers Sage, Zakutayev Andriy, 柴田浩幸, Kim Minesok, 柳博, 小俣孝久

第40回電子材料研究討論会　2020/11/12
SnS単結晶の溶液成長におけるハロゲン成分の寄与

川西咲子, 鈴木一誓, 小俣孝久, 柴田浩幸

第49回結晶成長国内会議(JCCG-49)　2020/11/11
スパッタリング法によるn型SnS薄膜の作製

鈴木一誓, 川西咲子, Bauers Sage, Zakutayev Andriy, 柴田浩幸, Kim Minesok, 柳博, 小俣孝久

第81回応用物理学会秋季学術講演会（オンライン開催）　2020/09/09
pnホモ接合SnSの作製と太陽電池特性

川西咲子, 鈴木一誓, Bauers Sage, Zakutayev Andriy, 柴田浩幸, 柳博, 小俣孝久

第81回応用物理学会秋季学術講演会（オンライン開催）　2020/09/09
コロイダルZn(Te1-xSx)量子ドットの合成とその光学特性

佃諭志, 稲吉晴子, 喜多正雄, 小俣孝久

第81回応用物理学会秋季学術講演会（オンライン開催）　2020/09/09
n型SnS薄膜のスパッタリング法による作製

鈴木一誓, 川西咲子, Bauers Sage, Zakutayev Andriy, 柴田浩幸, Kim Minesok, 柳博, 小俣孝久

資源・素材 2020　2020/09/09
副産物の有効利用に向けた機能材料開発：太陽電池材料 Enargite型 Cu3AsO4のイオン交換による合成

鈴木一誓, 小俣孝久, 渡邉寛人, 浅野聡

資源・素材 2020　2020/09/08
パルスレーザー堆積法によるウルツβ-NaGaO2薄膜の作製

鈴木惇市, 鈴木一誓, 小俣孝久, 喜多正雄

公益社団法人日本セラミックス協会第33回秋季シンポジウム（オンライン開催）　2020/09/02
n型SnS薄膜の作製

鈴木一誓, 川西咲子, Bauers Sage, Zakutayev Andriy, 柴田浩幸, Kim Minesok, 柳博, 小俣孝久

公益社団法人日本セラミックス協会第33回秋季シンポジウム（オンライン開催）　2020/09/02
ホットソープ法によるZn(Te1-xSx)混晶量子ドットの合成とその光学特性

佃諭志, 稲吉晴子, 喜多正雄, 小俣孝久

公益社団法人日本セラミックス協会第33回秋季シンポジウム（オンライン開催）　2020/09/01
Non-traditional oxide semiconductors for photovoltaic applications International-presentation Invited

T. Omata, I. Suzuki

15th International Ceramics Congress (CIMTEC 2020)
BaTiO3および SrTiO3単結晶中の Fe2+/3+遷移準位の決定

鈴木一誓, 小俣孝久, Leonard Gura, Andreas Klein

日本セラミックス協会 2020年・年会　2020/03/19
パルスレーザー堆積法による β-NaGaO2薄膜の作製

鈴木惇市, 鈴木一誓, 小俣孝久

日本セラミックス協会 2020年・年会　2020/03/19
コロイダルZn(Te1-xSx)混晶量子ドットの合成と光学特性

佃諭志, 稲吉晴子, 小俣孝久, 喜多正雄

日本セラミックス協会 2020年・年会　2020/03/18
Zn(Te1-xSx)量子ドットの合成と光学特性

佃諭志, 稲吉晴子, 喜多正雄, 小俣孝久

第67回応用物理学会春季学術講演会　2020/03/12
伝導度測定によるBaTiO3およびSrTiO3 中のFe2+/3+ 遷移準位の決定

鈴木一誓, 小俣孝久, Leonard Gura, Andreas Klein

2020年第67回応用物理学会春季学術講演会　2020/03/12
新機能光学材料の創製 Invited

OMATA Takahisa

産業技術総合研究所電子光技術研究部門光産業技術振興協会第9回電子光技術シンポジウム（機能性マテリアルの設計と実証－電子・光デバイスのイノベーション開拓に向けて－）　2019/12/20
Cl-doped n-type SnS single crystal International-presentation

I. Suzuki, S. Kawanishi, Y. Iguchi, K. Sato, T. Omata, H. Yanagi

2019 MRS Fall Meeting　2019/12/01
Development of Mist-CVD Equipment for β-NaGaO2 Thin-Film Deposition International-presentation

T. Watanabe, S. Suzuki, I. Suzuki, T. Omata

An-Pang Tsai Memorial Joint Symposium of Taipei Tech and Tohoku University　2019/11/24
高リスク非鉄素材を活用した機能性材料開発の環境整備

OMATA Takahisa

令和元年日本鉱業振興会助成による研究発表会　2019/11/01
Phase transformations of the narrow gap oxide semiconductor Cu2ZnGeO4 with wurtzite-derived structure in Ar atmosphere International-presentation

M. Kita, I. Suzuki, N. Wada, T. Omata

The 13th Pacific Rim Conference of Ceramic Societies (PACRIM13)　2019/10/28
Band alignment and Fermi level shift of β-CuGaO2 International-presentation

I. Suzuki, A. Klein, T. Omata

11th International Symposium on Transparent Oxide and Related Materials for Electronics and Optics (TOEO 11)　2019/10/07
Synthesis and optical properties of Zn(Te1−xSex) quantum dots using zinc acetate as a zinc source International-presentation

S. Tsukuda, M. Kita, T. Omata

11th International Symposium on Transparent Oxide and Related Materials for Electronics and Optics (TOEO 11)　2019/10/07
パルス通電焼結装置を用いたClドープSnS焼結体の作製

西村肇, 平井伸治, 鈴木一誓, 小俣孝久, 川西咲子

資源・素材2019（京都）　2019/09/24
副産物の有効利用に向けた機能材料開発；Enargite型Cu3As(S,O)4の太陽電池材料としてのポテンシャル

鈴木一誓, 小俣孝久, 大橋直樹, 渡邉寛人, 浅野聡

資源・素材2019（京都）　2019/09/24
n型SnS単結晶の電子状態

鈴木一誓, 川西咲子, 井口雄喜, 佐藤孝一, 小俣孝久, 柳博

第80回応用物理学会秋季学術講演会　2019/09/18
酢酸亜鉛を原料としたZn(Te1-xSex)量子ドットの合成と光学特性

佃諭志, 小俣孝久

第80回応用物理学会秋季学術講演会　2019/09/18
無鎘量子點的材料、合成、特性及其應用 International-presentation Invited

OMATA Takahisa

台灣平面顯示器材料與元件產業協會専業課程(Taiwan Flat Panel Display Materials and Devices Association Seminar　2019/09/17
60分でわかる量子ドット蛍光体；その基礎から応用 Invited

OMATA Takahisa

SID日本支部第15回サマーセミナー　2019/08/22
プロトン伝導性リン酸塩ガラス電解質；ITFC用電解質としての可能性 Invited

OMATA Takahisa

第115回 SOFC研究会　2019/08/01
量子ドット蛍光体材料の開発とディスプレイへの応用－カドミウムフリー化への取り組みと発光素子開発の動向－ Invited

佃諭志, 小俣孝久

日本実装技術振興協会高密度実装技術部会 2019年7月定例会　2019/07/18
Electronic structure and band alignment of ternary wurtzite-type oxide semiconductor, β-CuGaO2 International-presentation

I. Suzuki, N. Ohashi, A. Klein, T. Omata

The 11th International Conference on the Science and Technology for Advanced Ceramics (STAC-11)　2019/07/09
Quantum Dot Phosphors Containing NoneQuantum Dot Phosphors Containing None of Hazardous Element; ZnTe-Based Alloy Quantum DotsDots International-presentation Invited

T. Omata, S. Tsukuda, H. Asano

Display Week 2019 Society for Information Display, International Symposium, Seminar & Exhibition　2019/05/12
Synthesis and optical properties of cadmium-free colloidal II–VI alloy quantum dot phosphor International-presentation Invited

S. Tsukuda, H. Asano, T. Omata

China Society for Information Display, International Conference on Display Technology (ICDT 2019)　2019/03/26
ミストCVD 法によるβ-NaGaO2 薄膜の作製とβ-CuGaO2 薄膜へのイオン交換

鈴木一誓, 竹村沙友理, 小俣孝久

日本セラミックス協会 2019年年会　2019/03/24
プロトン伝導性リン酸塩ガラス・融液のプロトン移動度

小俣孝久, 山口拓哉, 佃諭志, 石山智大, 西井準治, 山下俊晴, 川副博司

第44回固体イオニクス討論会　2018/12/06
Fabrication of β-CuGaORR2RR films using β-NaGaORR2RR precursor films prepared by mist CVD method International-presentation

S. Takemura, I. Suzuki, T. Omata

Kick Off Symposium of Academic Exchange Program for TAIPEI TECH-IMRAM　2018/12/03
High temperature photoluminescence properties of quantum dots phosphors International-presentation

H. Inayoshi, S. Tsukuda, T. Omata

Kick Off Symposium of Academic Exchange Program for TAIPEI TECH-IMRAM　2018/12/03
Design and synthesis of novel inorganic materials International-presentation Invited

T. Omata, I. Suzuki, S. Tsukuda

International Symposium on “New Horizon in Advanced Materials”　2018/12/03
Mobility of Proton Carriers in Proton Conducting Phosphate Glasses International-presentation

T. Omata, T. Yamaguchi, S. Tsukuda, J. Nishii, T. Yamashita, H. Kawazoe, T. Ishiyama

2018 MRS Fall Meeting, 2018　2018/11/25
ウルツ鉱型関連構造のナローギャップ酸化物半導体Cu2ZnGeO4の高温相変化

喜多正雄, 和田憲幸, 鈴木一誓, 小俣孝久

第21回日本セラミックス協会北陸支部秋季研究発表会　2018/11/23
Pb, Cd, As フリー材料開発の将来

OMATA Takahisa

第38回エレクトロセラミックス研究討論会　2018/11/16
カドミウムフリーⅡ-Ⅵ族半導体量子ドット蛍光体の材料設計・合成・光学特性

佃諭志, 小俣孝久, 浅野洋

The 38th Electronics Division Meeting of the Ceramic Society of Japan　2018/11/15
三元系ウルツ鉱型酸化物：β-CuGaO2の電子構造とバンドアライメント

鈴木一誓, 大橋直樹, Andreas Klein, 小俣孝久

第38回エレクトロセラミックス研究討論会　2018/11/15

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発表奨励賞
Material design and experimental demonstration of cadmium-free and II-VI semiconductor quantum dot phosphors exhibiting green and red emissions International-presentation Invited

T. Omata, H. Asano, S. Tsukuda, M. Kita

Nanotechnology and Material Science Congress　2018/11/12
高温におけるコロイダル量子ドット蛍光体の発光特性

稲吉晴子, 佃諭志, 小俣孝久

平成30年度日本セラミックス協会東北北海道支部研究発表会　2018/11/03

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優秀発表賞
ナローバンドギャップ酸化物半導体：β-CuGaO2の電子構造とバンドアライメント

鈴木一誓, 大橋直樹, アンドレアス・クライン, 小俣孝久

平成30年度日本セラミックス協会東北北海道支部研究発表会　2018/11/02
Functional Materials Containing Arsenic and Other Hazardous Elements - Development and practical use of new materials containing hazardous elements for sustainable society - International-presentation Invited

T. Omata

Internatinal Seminar on Impurityes of Copper Raw Materials　2018/10/17
Potential of Proton Conducting Phosphate Glasses as Fuel Cell Electrolytes International-presentation

T. Omata, M. Tashiro, I. Suzuki, T. Yamaguchi, T. Ishiyama, J. Nishii, T. Yamashita, H. Kawazoe

19th International Conference on Solid State Proton Conductors (SSPC19)　2018/09/16
Fabrication of β-CuGaO2 Thin Films International-presentation

I. Suzuki, H. Nagatani, M. Kita, T. Omata

10th International Workshop on Zinc Oxide and Other Oxide Semiconductors (IWZnO 2018)　2018/09/12
Conductivity Control of Ternary Wurtzite β-AgGaO2 by Impurity Doping International-presentation

I. Suzuki, H. Nagatani, S. Takemura, M. Kita, T. Omata

10th International Workshop on Zinc Oxide and Other Oxide Semiconductors (IWZnO 2018)　2018/09/12
Synthesis and optical properties of Zn(Te, Se)/ZnS core/shell quantum dots; Cadmium-free and green QD-phosphor International-presentation

Satoshi Tsukuda, Hiroshi Asano, Masao Kita, Takahisa Omata

EL2018　2018/09/11
Cu deficiency in the narrow gap oxide semiconductor Cu2ZnGeO4 with wurtzite-derived structure International-presentation

M. Kita, I. Suzuki, N. Wada, T. Omata

10th International Workshop on Zinc Oxide and Other Oxide Semiconductors (IWZnO2018)　2018/09/09
プロトン伝導性リン酸塩ガラスのプレス加工による薄板化

田代真敬, 山口拓哉, 石山智大, 鈴木一誓, 西井準治, 山下俊晴, 川副博司, 小俣孝久

公益社団法人日本セラミックス協会第31回秋季シンポジウム　2018/09/07
コロイド状量子ドット蛍光体の高温における温度依存性

稲吉晴子, 佃諭志, 小俣孝久

公益社団法人日本セラミックス協会第31回秋季シンポジウム　2018/09/06
ミストCVD法によるβ-NaGaO2薄膜の作製

竹村沙友理, 鈴木一誓, 小俣孝久

公益社団法人日本セラミックス協会第31回秋季シンポジウム　2018/09/05
プロトン伝導性リン酸塩ガラスのホットプレスによる薄板化

鈴木一誓, 田代真敬, 山口拓哉, 石山智大, 西井準治, 山下俊晴, 川副博司, 小俣孝久

第14回固体イオニクスセミナー　2018/09/02
カドミウムフリーII-VI族半導体量子ドット蛍光体の開発「巨大バンドギャップボーイングを利用した量子ドットの光学ギャップ制御」 Invited

佃諭志, 小俣孝久

第373回蛍光体同学会講演会　2018/08/31
XPS study of the band alignment of β-CuGaO2 with other oxides International-presentation

I. Suzuki, A. Klein, T. Omata

Data Science in Life Science and Engineering Collaboration and Symposium, 5th CWRU-Tohoku Joint Workshop　2018/08/03
Wurtzite-type and narrow-band-gap oxide semiconductor, β-CuGaO2, and its derived materials International-presentation Invited

T. Omata

5th CWRU-Tohoku Joint Workshop　2018/08/02
コロイダル量子ドット蛍光体の材料開発と応用；現状と将来 Invited

小俣孝久

新科学技術推進協会(JACI) 電子情報技術部会エレクトロニクス交流会講演会「量子ドットが拓く未来」　2018/07/24
Green and narrow-band emission of Zn(Te, Se)/ZnS core/shell quantum dots International-presentation

Satoshi Tsukuda, Hiroshi Asano, Masao Kita, Takahisa Omata

10th International Conference on Quantum Dots (QD2018)　2018/06/25
Design of cadmium-free and II-VI semiconductor quantum dot phosphors exhibiting green and red emissions International-presentation

Takahisa Omata, Hiroshi Asano, Masao Kita

10th International Conference on Quantum Dots (QD2018)　2018/06/25
不純物ドーピングによるβ-AgGaO2の伝導性制御

竹村沙友理, 鈴木一誓, 長谷拓, 喜多正雄, 小俣孝久

資源・素材学会平成30年度東北支部総会・春季大会　2018/05/25
混晶Zn(Te1-xSex)/ZnSコアシェル量子ドットの合成と光学特性

佃諭志, 小俣孝久, 浅野洋, 喜多正雄

日本セラミックス協会 2018年・年会　2018/03/15
中温域で高いプロトン移動度を発現するリン酸塩ガラス

山口拓哉, 佃諭志, 小俣孝久, 石山智大, 西井準治, 山下俊晴, 川副博司

日本セラミックス協会 2018年・年会　2018/03/15
電気化学的アルカリ-プロトン置換により作製したリン酸塩ガラスのプロトン移動度

山口拓哉, 佃諭志, 小俣孝久, 片岡拓也, 斎藤泰久, 桑原泰隆, 山下弘巳, 石山智大, 西井準治, 山下俊晴, 川副博司

日本セラミックス協会 2018年・年会　2018/03/15
ウルツ鉱型酸化物半導体 β-AgGaO2の伝導性制御

竹村沙友理, 長谷拓, 鈴木一誓, 小俣孝久

日本セラミックス協会 2018年・年会　2018/03/15
ウルツ鉱型関連構造のナローギャップ酸化物半導体 Cu2ZnGeO4の結晶構造と電子構造の解析

喜多正雄, 井上誠, 鈴木一誓, 大橋直樹, 小俣孝久

日本セラミックス協会 2018年・年会　2018/03/15
量子ドット蛍光体の基礎とカドミウムフリー化技術の動向 Invited

小俣孝久

International Display Workshop ‘17　2017/12/04
Crystal and electronic structure of quaternary narrow gap oxide semiconductor Cu2ZnGeO4 with a wurtzite-derived structure International-presentation

M. Kita, I. Suzuki, I. Makoto, T. Omata

2017 MRS Fall Meeting　2017/11/28
コロイダル半導体量子ドットの材料設計と合成 Invited

小俣孝久

平成29年度電気化学会東北支部第48回セミコンファレンス　2017/11/25
ウルツ鉱関連構造のナローギャップ酸化物半導体 Cu2ZnGeO4の結晶構造と電子構造

喜多正雄, 鈴木一誓, 小俣孝久

第２０回日本セラミックス協会北陸支部秋季研究発表会　2017/11/24
コロイダル半導体量子ドットの材料設計と合成 Invited

小俣孝久

平成29年表面技術協会関西支部講演会　2017/11/17
コロイダル量子ドットの材料設計と合成プロセス Invited

小俣孝久

産業技術総合研究所ナノ材料設計・プロセス研究会　2017/10/12
Wurtzite-type ternary I-III-O2 oxide semiconductors; new materials expanding the energy band gap range covered by oxide semiconductors International-presentation Invited

T. Omata

2017 Transparent Conductive Oxide - Fundamentals and Applications　2017/09/18
プロトン伝導性酸化物の材料開発 Invited

小俣孝久

第13回固体イオニクスセミナー　2017/09/12
Wurtzite-type Narrow Band Gap Oxide Semiconductor, β-CuGaO2, and Its Derived Materials International-presentation Invited

T. Omata

The 10th International Conference on the Science and Technology for Advanced Ceramics (STAC-10)　2017/08/01
Wurtzite-Type and Narrow Band Gap Oxide Semiconductor, β-CuGaO2, and Its Derived Materials International-presentation Invited

T. Omata

The 10th International Conference on the Science and Technology for Advanced Ceramics　2017/08/01
Proton carrier injection into Na3Zr2Si2PO12 by electrochemical alkali-proton substitution at high temperature International-presentation

S. Tsukuda, K. Miyake, T. Yamaguchi, T. Ishiyama, J. Nishii, T. Yamashita, H. Kawazoe, T. Omata

21st International Conference on Solid State Ionics　2017/06/18
Proton transport property of phosphate glass fabricated via alkali-proton substitution International-presentation

T. Ishiyama, T. Yamaguchi, S. Tsukuda, J. Nishii, T. Yamashita, H. Kawazoe, T. Omata

21st International Conference on Solid State Ionics　2017/06/18
Proton Conducting Phosphate Glass Exhibiting High Conductivity at Intermediate Temperatures International-presentation

T. Yamaguchi, J. Nishii, T. Yamashita, H. Kawazoe, T. Ishiyama, T. Omata

21st International Conference on Solid State Ionics　2017/06/18
Mobility of Proton Carriers in Phosphate Glasses International-presentation

T. Omata, T. Yamaguchi, S. Tsukuda, J. Nishii, T. Yamashita, H. Kawazoe, T. Ishiyama

21st International Conference on Solid State Ionics　2017/06/18
アルカリ−プロトン置換したリン酸塩ガラスの伝導特性

木下拓也, 藤岡正弥, 海住英生, 西井準治, 山口拓哉, 小俣孝久

日本セラミック協会2017年年会　2017/03/17
希土類含有ガラスのプロトン伝導特性

舘林尭, 木下拓也, 藤岡正弥, 海住英生, 西井準治, 山口拓哉, 小俣孝久

日本セラミック協会2017年年会　2017/03/17
ウルツ鉱型関連構造の4元系ナローギャップ酸化物半導体Cu2ZnGeO4の高温における相変化

喜多正雄, 井上誠, 和田憲幸, 鈴木一誓, 長谷拓, 小俣孝久

日本セラミック協会2017年年会　2017/03/17
ゲルナノワイヤー上でのAuナノ粒子形成とLSPR制御

佃諭志, 関修平, 杉本雅樹, 小俣孝久

第64回応用物理学会春季学術講演会　2017/03/14
酸化物の形態・構造制御−酸化亜鉛量子ドット，新しい酸化物半導体を中心に− Invited

小俣孝久

機能性酸化物膜の液相エピタキシャル結晶成長研究会　2017/03/06
中温域で高いプロトン移動度を発現するリン酸塩ガラス

山口拓哉, 片岡拓也, 斎藤泰久, 西井準治, 山下俊晴, 川副博司, 石山智大, 山地克彦, 小俣孝久

第42回固体イオニクス討論会　2016/12/05
Development of Cadmium Free Semiconductor Quantum Dot Phosphor International-presentation Invited

T. Omata

The 33rd International Korea-Japan Seminar on Ceramics　2016/11/16
Development of Cadmium Free Semiconductor Quantum Dot Phosphors International-presentation Invited

T. Omata

The 33rd international Korea-Japan Seminor on Ceramics　2016/11/16
Formation of Au nanoparticle arrays on hydrogel 2-D patterns based on poly(vinylpyrrolidone) International-presentation

S. Tsukuda, K. Okamoto, H. Yamamoto, T. Kozawa, T. Omata

29th International Microprocesses and Nanotechnology Conference (MNC 2016)　2016/11/08
Control of Electrical Conductivity of Ternary Wurtzite β-AgGaO2 International-presentation

H. Nagatani, I. Suzuki, M. Kita, T. Omata

The 9th International Workshop on Zinc Oxide and Related Materials (IWZnO 2016)　2016/10/30
Flux growth of ternary wurtzite β-NaGaO2 and β-LiGaO2 single crystals International-presentation

A. Kakinuma, I. Suzuki, M. Ueda, T. Omata

The 9th International Workshop on Zinc Oxide and Related Materials (IWZnO 2016)　2016/10/30
New quaternary narrow gap oxide semiconductor Cu2ZnGeO4 with a wurtzite-derived Structure International-presentation

M. Kita, I. Suzuki, H. Nagatani, Y. Mizuno, M. Inoue, T. Omata

The 9th International Workshop on Zinc Oxide and Related Materials (IWZnO 2016)　2016/10/30
Band Gap Engineering of Wurtzite β-CuGaO2 by Alloying with β-CuAlO2 and β-LiGaO2 and Their Electronic Structures International-presentation

T. Omata, H. Nagatani, Y. Mizuno, I. Suzuki, M. Kita, N. Ohashi

The 9th International Workshop on Zinc Oxide and Related Materials (IWZnO 2016)　2016/10/30
高い耐熱性とプロトン伝導を示す希土類含有リン酸塩ガラスの作製

舘林尭, 木下拓也, 山口拓哉, 藤岡正弥, 海住英生, 小俣孝久, 西井準治

平成28年度日本セラミックス協会東北北海道支部研究発表会　2016/10/27
Band Gap Engineering of Wurtzite-Type Narrow Band Gap Oxide Semiconductor β-CuGaO2 International-presentation

T. Omata, Y. Mizuno, H. Nagatani, I. Suzuki, M. Kita

Pacific Rim Meeting on Electrochemical and Solid-State Science 2016 (PRiME 2016)　2016/10/02
Mobility of Proton Carriers in Proton Conducting Phosphate Glasses Fabricated by Electrochemical Substitution of Sodium Ions with Protons International-presentation

T. Omata, T. Yamaguchi, T. Kataoka, Y. Saito, J. Nishii, T. Yamashita, H. Kawazoe

18th International conference on Solid State Protonic Conductors (SSPC-18)　2016/09/18
New Proton Conducting Phosphate Glass Fabricated by Electrochemical Alkali-Proton Substitution at Intermediate Temperature International-presentation

T. Yamaguchi, K. Miyake, J. Nishii, T. Yamashita, H. Kawazoe, T. Ishiyama, H. Kishimoto, K. Yamaji, T. Omata

18th International conference on Solid State Protonic Conductors (SSPC-18)　2016/09/18
Investigation of electrode performance for the proton conducting phosphate glass fabricated via alkali-proton substitution technique International-presentation

T. Ishiyama, H. Kishimoto, K. Yamaji, T. Yamaguchi, T. Omata

18th International conference on Solid State Protonic Conductors (SSPC-18)　2016/09/18
コロナ放電処理で作製したプロトン伝導ガラスの評価

木下拓也, 山口拓哉, 藤岡正弥, 海住英生, 小俣孝久, 西井準治

平成28年度日本セラミックス協会東北北海道支部研究発表会　2016/09/13
コロイダルInAs量子ドットの生成反応におけるアミンの作用

片岡拓也, 上杉秀雄, 柿沼綾子, 喜多正雄, 金折賢二, 小俣孝久

資源・素材2016（盛岡）　2016/09/13
Na+イオンのプロトン置換によるNa3Zr2Si2PO12 (NASICON)のアモルファス化

三宅啓吾, 山口拓哉, 西井準治, 山下俊晴, 川副博司, 小俣孝久

資源・素材2016（盛岡）　2016/09/13
Na+イオンのプロトン置換によるNa3Zr2Si2PO12(NASICON)の

三宅啓吾, 山口拓哉, 小俣孝久, 西井準治, 川副博司, 山下俊晴

日本セラミックス協会関西支部学術講演会　2016/07/29
コロイダルInAs量子ドットの生成反応におけるアミンの作用

片岡拓也, 上杉秀雄, 柿沼綾子, 喜多正雄, 小俣孝久

日本セラミックス協会関西支部学術講演会　2016/07/29
Ternary and Quaternary Wurtzite-type Oxide Semiconductors: β-CuGaO2 and Its Related Materials International-presentation Invited

T. Omata, Y. Mizuno, I. Suzuki, H. Nagatani, M. Kita

The 43rd International Symposium on Compound Semiconductors (ISCS 2016)　2016/06/30
Ternary and Quaternary Wurtzite-type Oxide Semiconductors: β-CuGaO2 and Its Related Materials International-presentation Invited

T. Omata

The 43rd International Symposium on Compound Semiconductors; ISCS 2016　2016/06/26
Proton-conducting phosphate glasses stable a t intermediate temperatures International-presentation Invited

T. Omata, T. Yamaguchi, T. Ishiyama, A. Miyazaki, J. Nishii, T. Yamashita, H. Kawazoe

Rare Earths 2016　2016/06/05
アルカリ−プロトン置換したリン酸塩ガラスの伝導特性と熱的特性

木下拓也, 宮崎篤, 藤岡正弥, 海住英生, 西井準治, 山口拓哉, 小俣孝久

日本セラミック協会2016年年会　2016/03/16
I-III-VI2 Colloidal Semiconductor Quantum Dots; The Present and The Future International-presentation Invited

T. Omata

28th International Microprocesses and Nanotechnology Conference (MNC 2015)　2015/11/10
Wurtzite-derived ternary I-III-O2 semiconductors International-presentation Invited

T. Omata

9th International Symposium on Transparent Oxide Thin Films for Electronics and Optics (TOEO-9)　2015/10/19
Ternary and quaternary wurtzite-type oxide semiconductors: new materials and their properties International-presentation Invited

T. Omata

SPIE Photonics West 2015; Oxide-based Materials and Devices VI　2015/02/08

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Industrial Property Rights 10

プロトン伝導性材料、固体電解質膜、及びプロトン伝導性材料の製造方法

川副博司, 山下俊晴, 小俣孝久, 西井準治, 石山智大

Property Type: Patent
コアシェル型量子ドット蛍光微粒子

小林哲, 井口由紀, 小俣孝久, 橋本真一, 野瀬勝弘

Property Type: Patent
蛍光体、およびその製造方法

中村浩之, 前田英明, 小俣孝久, 上原雅人

Property Type: Patent
可視光域でも触媒活性を有する光触媒

松尾伸也, 小俣孝久

Property Type: Patent
可視光域でも触媒活性を有する光触媒

松尾伸也, 小俣孝久

Property Type: Patent
可視光域でも触媒活性を有する光触媒

松尾伸也, 小俣孝久

Property Type: Patent
光触媒

松尾伸也, 小俣孝久

Property Type: Patent
立方晶錫−タンタル複合酸化物とその製造方法

松尾伸也, 小俣孝久

Property Type: Patent
複合酸化物から成る光触媒とその製造方法

松尾伸也, 小俣孝久

Property Type: Patent
可視光域でも触媒活性を有する光触媒

松尾伸也, 小俣孝久

Property Type: Patent

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Research Projects 29

リン酸塩ガラス中のプロトン輸送を律する機構の解明；高速プロトン伝導の実現に向けて

小俣孝久, 山崎智之, 鈴木一誓

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(A)

Institution: 東北大学

2024/04/01 - 2027/03/31
Novel synthesis method for inorganic materials: electrochemical cation substitution

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Tohoku University

2022/06/30 - 2024/03/31
次世代燃料電池ITFCを実現する電極反応の全貌解明とその高速化

小俣孝久, 石山智大, 鈴木一誓

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(A)

Institution: 東北大学

2021/04/05 - 2024/03/31

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本年度は各種評価に供するWO3焼結体および薄膜の作製方法を重点的に検討し、高密度焼結体の作製方法を確立するとともに、薄膜の堆積条件が薄膜組織、生成相に与える効果を明らかにした。特に薄膜においては、電極性能に有利と思われる粒径5nm程度のナノ結晶の堆積条件を明らかにした。このような組織は従来報告されていない新たな発見である。これらの試料を用いて以下を行った。 (1-a) 昇温脱離分析による吸着気体の定性および定量分析：300℃の水素雰囲気で水素を注入したWO3焼結体の昇温脱離を行った。WO3バルクに溶解した水素を定量した。バルク溶解した水素は、昇温脱離により主にH2Oとして脱離し、H2Oの1/50程度がH2として脱離することを明らかにした。H2として脱離する水素は表面吸着した水素を含む。 (1-b) 水素および酸素の表面交換反応速度の評価・解析： 2H(D)および18Oの濃度の深さプロファイルのSIMS測定に供するWO3焼結体の同位体交換条件を検討した。 (1-c) インピーダンス解析による電極抵抗の評価・解析：WO3焼結体のプロトン伝導度評価法を見直し、電子ブロッキング電極を用いた直流伝導度測定により、混合伝導性の詳細を明らかにするとともに、各種電極候補材料に適用可能な混合伝導性の評価方法を確立した。 (2-a) ラマン分光法による吸着酸素とWO3酸化物表面の化学状態解析：購入した高温雰囲気調整ステージを改造しラマン分光測定の方法を確立した。 (2-b) X線光電子分光法による吸着気体分子と電極材料の電子状態の評価解析：酸素分圧の異なる雰囲気で作製したWO3薄膜を前処理なしにXPS測定し、W5+/W6+イオンの状態がXPSで捕捉できることを確認した。また価電子帯スペクトル、O1sスペクトルから、それらに与える吸着酸素の効果の測定方法を検討した。
超高密度プロトン含有リン酸塩ガラスのプロトン移動の科学と高速プロトン伝導性の実現

西井準治, 小野円佳, 石山智大, 小俣孝久

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(B)

Institution: 北海道大学

2020/04/01 - 2023/03/31

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本研究は、北大グループと東北大・産総研グループが連携して、リン酸塩ガラスのプロトン移動度の支配因子を学術的に明らかにすることを目的としている。北大グループは、Na2O-La2O3-GeO2-P2O5系ガラスにおいて、LaをGeに置換することでプロトン伝導度が上昇する現象を見いだしていたが、その原因は未解明であった。そこで、東北大・産総研グループ、およびNIMSと連携して、ガラス構造とプロトン伝導度の相関の解明に取り組みんだ。SPringの高エネルギーX線回折測定によってGeが6配位であることが明らかとなり、XPS,NMR測定より、P-O-Ge結合の形成がプロトンの移動度の向上に重要な役割を担っていると推察された。本研究は、ガラスにおけるカチオン移動現象に関する重要な知見であることから、体系的に整理した上で論文投稿する予定である。また、北大グループは、Na2O-SiO2-P2O5系ガラスにおいて、Naの90%以上をプロトンに置換することでプロトン伝導が発現することを見出した。この組成系は、現在までに報告されている中で最も単純な3成分系である。最近、高エネルギーX線回折測定によりSiが6配位であり、プロトン伝導の活性化エネルギーが、これまで検討してきたガラス系の中で最も高い1.2eV以上であることが分かった。このガラス系は、本研究課題の目標である『ガラスにおけるカチオン移動現象の科学』を深める上で重要であることから、東北大・産総研グループと連携して、プロトン伝導とガラス構造との相関について詳しく検討する予定である。
Development of novel cathode materials to realize intermediate temperature fuel cells; A major change of the material exploring field

Omata Takahisa

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Tohoku University

2019/06/28 - 2021/03/31

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The proton conductivity of H0.39WO3 was determined to be 1.4×10-3 to 1.1×10-1Scm-1 at 300°C from the hydrogen permeation measurement and the proton conductivity measurement using a phosphate glass as a blocking electrode. This value is higher than the proton conductivity of phosphate glass electrolytes, indicating that the proton conductivity of WO3 is extremely high and the WO3-based materials have high potential as a cathode material. The electronic conductivity of the WO3-based material was successfully maintained at 10 Scm-1 in air at 300°C by Ca0.02HxWO3; the electronic conductivity is sufficient for cathode materials.
New Developments in Oxide Semiconductors; Material Science and Device Technology of Narrow-Gap Wurtzite Oxides

Omata Takahisa

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2017/04/01 - 2021/03/31

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In this study, we investigated mist CVD and PLD methods for the fabrication of β-NaGaO2 thin films, which are precursors of β-CuGaO2. For the mist-CVD method, we developed a new deposition apparatus. By using the new apparatus, deposition of β-NaGaO2 thin film with nearly stoichiometric composition (average composition of Na:Ga=1:0.91) and homogeneous morphology was successful. For the PLD method, we succeeded in depositing β-NaGaO2 thin film with stoichiometric composition and homogeneous microstructure by reducing the distance between target and substrate. XPS analysis revealed that the band alignment of β-CuGaO2 and Al-doped ZnO is Type II, and the electrons and holes generated by photoexcitation are separated, indicating that the p/n junctions of β-CuGaO2 with ZnO is applicable to thin-film solar cells.
Stabilization of proton carriers in rare-earth elements containing glasses; new developments of intermediate-temperature fuel cells

Nishii Junji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Hokkaido University

2017/04/01 - 2020/03/31

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The purpose of this study is the development of high proton conductive electrolyte glass for the intermediate temperature fuel cell operating between 250-500℃. Using our original alkali-proton substitution method (APS), following two research issues were conducted; (1) optimization of composition of phosphate glass containing rare-earth elements, (2) sustention of high proton conductivity for long time. A phosphate glass containing 35 mol% NaO1/2 and 5 mol% GdO3/2 exhibited the conductivity of 0.002 S/cm for 500 h at 310℃. The phase separation and subsequent crystallization were occurred after 500 h. On the other hand, the quadrupole mass spectrometry revealed that the desorption temperature of H2O molecule from the glass were located above 450℃. Therefore, the progress of proton conductivity is expected by the further composition improvement.
Developing of solid state electrolytes for intermediate temperature fuel cells; Exploring of new materials using high-temperature alkali-proton substitution technique

Omata Takahisa

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

2015/04/01 - 2017/03/31

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We explored the proton conducting solid oxide crystals exhibiting high electrical conductivity at intermediate temperatures using electrochemical substitution of Na+ ions with protons at intermediate temperatures (APS). Although we have not been successful to obtain solid oxides exhibiting high proton conductivity, we have found out very interesting phenomenon in APS for Na3Zr2Si3PO12 (NASICON). While the crystal structure of NASICON was maintained up to the 50% substitution of Na+ ions with protons, it became amorphous above 50% substitution of Na+ ions with protons. This observation was explained in terms of the internal pressure introduced by the volume shrinkage during the substitution.
Ternary wurtzite-type narrow band gap oxide semiconductor; Fabrication of thin-films and application to thin-film solar cells

Omata Takahisa

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

2014/04/01 - 2017/03/31

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We studied fabrication method of β-CuGaO2 thin-films. First, we fabricated β-NaGaO2 thin-films as precursor materials; then, the film was subjected to ion-exchange of Na+ ions in the precursor films with Cu+. We successfully fabricated β-NaGaO2 thin-films by magnetron sputtering using β-NaGaO2 as a target material. β-CuGaO2 thin-films that exhibits good surface morphology were fabricated by ion-exchange of Na+ ions in the precursor β-NaGaO2 thin-film with Cu+ ions in CuCl vapor. Although the preferential orientation of the β-NaGaO2 films could not be controlled by magnetron sputtering, it was successfully controlled using electron-beam evaporation and sapphire substrates with various crystal orientations. However, the composition of precursor β-NaGaO2 film fabricated by sputtering and evaporation methods exhibited Na-poor composition. We found CVD is the preferable method to fabricate high quality and stoichiometric β-NaGaO2 precursor films.
Exploring of I-III-VI2 oxide semiconductors and their new functions

OMATA Takahisa, OHASHI Naoki, YANAGI Hiroshi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Osaka University

2013/04/01 - 2015/03/31

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Crystal structure of β-CuGaO2 was refined and its stability was evaluated using TG-DTA and high temperature XRD. Aa a result, this material is a metastable phase, but practically stable <300°C even under oxygen atmosphere. Impurity doping was attempted, and possibility of carrier injection by impurity doping was suggested. Based on the first principles density functional calculation, it was shown that β-CuGaO2 intensely absorb light around the fundamental absorption edge; therefore, it was shown that this material is a promising oxide semiconductor as a solar cell absorber.
Miniband formation in quantum dot amorphous and its application to photovoltaic devices

OMATA Takahisa, KITA Masao

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Osaka University

2011/04/01 - 2014/03/31

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We focused on to develop quantum dot (QD) solar cells that show extremely high conversion efficiency. For this purpose, we investigated synthesis method of colloidal InAs QDs; the InAs QDs show lower threshold energy for multiple exciton generation than PbSe QDs that are currently used in QD solar cell investigations. We focused on the triphenyl arsine that is comparatively safe and easy to handle rather than the conventional tris(trimethylsilyl)arsine as an arsenic source. We successfully developed a new synthesis route to colloidal InAs QDs. Further, we investigated miniband formation in quantum dot amorphous, of which the density of QD is significant larger than that in conventional self-assembled QD films but no periodicity is exist in the QD arrangement. Miniband formation was clearly observed for the PbSe quantum dots, but it was not observed for the CdSe and PbS QDs. This indicates that the miniband formation is significantly dependent on the exciton Bohr radius.
Invention and itsguiding principle of new alloying system of zinc oxide realizing optoelectronic function in visible lights

OMATA Takahisa, OHASHI Naoki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Osaka University

2011 - 2012

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The novel pseudo-binary alloy system (1-x)ZnO-x(AgGaO2)1/2i s demonstrated by rf-magnetron sputtering using mixed powders of ZnO and β-AgGaO2with various mixing ratio as target materials. The energy band gap of ZnO is decreased with the increasing the AgGaO2concentration, and it reaches to 2.55eV (485nm). This alloy system is non-toxic unlike the previous reported alloy, i.e, ZnO-CdO, then this is suitable for the practical applications of ZnO in visible light region.
Fabrication of high temperature proton conductors using electric field accelerated proton-alkali total replacement

NISHII Junji, NISHIYAMA Hiroaki, OMATA Takahisa

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Hokkaido University

2011 - 2012

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Corona discharge treatment replaced an alkali ion to proton in a tungsten containing phosphate and an aluminosilicate glasses. The atmosphere containing H2 gas was effective to increase the alkali depression layer thickness. There was a difference in the coloration of the corona discharged glasses containing WO3 or Nb2O3. There should be a glass network changes during the corona discharge without the simple alkali-proton exchange.
High Speed Reaction Field of Stable/ Metastable Phases Mixed in Nano-scale and Its Applications

MATSUO Shinya, OMATA Takahisa, KITA Masao

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (S)

Institution: Osaka University

2007 - 2011

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Several resembling CaF_2-like phases could coexist in the Zr-Ce-Pr-O system which were originated from the Zr-Ce-O and Zr-Pr-O systems. When the analogous particles with appropriate compositions are connected coherently by sintering, oxygen deficient-sites may be introduced and on the contrary oxygen intercalation may also occur in the interface region. When optimizing the phenomena, complex oxides involving stable/ metastable phases have demonstrated their potentials as superior reaction fields for exhaust gas catalyst and methane-steam reforming.
電子活性ハライドマテリアルズ・サイエンスの黎明

小俣孝久

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 挑戦的萌芽研究

Institution: 大阪大学

2009 - 2010

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本年度は電子ビーム蒸着法によるZnF_2薄膜の作製を検討した。市販されている各種の無水ZnF_2を購入し、粉末XRDにより解析したところ、Zn(OH)Fを含むものが見出された。Zn(OH)Fを不純物として含むものは、焼結時の脱水により酸化亜鉛を生成し純粋なフッ化物とはならなかった。市販試薬の中から純粋なZnF_2であるものを選択し、ベース圧力3×10^<-6>Paの真空下で焼結することで、酸化亜鉛を含まないZnF_2を作製した。得られた焼結体を蒸着源として、ベース圧力9×10^4Pa以下の真空中で電子ビーム蒸着した。基板にはSiO_2ガラス,(0001)面(c面)および(1120)面(a面)サファイア単結晶を使用した。SiO_2ガラスおよびa面サファイア基板では無配向の、c面サファイア基板では(100)配向のルチル型ZnF_2薄膜が得られた。(100)配向膜は酸素の六方最密面であるサファイアc面上に、ルチル構造のフッ素の立方最密面(a面)がエピタキシャル成長した結果であることが明らかとなった。AFMによる観察から、いずれの膜も10～50nmの粒子からなり、rmsで1～2nmの非常に平坦な膜であることが示された。光透過スペクトルの測定により、近赤外から紫外線の非常に広い領域で透明な薄膜であることが示された。真空紫外領域での透過スペクトルの測定から、バンドギャップは約6.7eVであることが明らかとなった。蒸着源に5at%のAIF3の添加したZnF_2を使用することで、キャリア電子のドーピングを試みたが、明らかな伝導性の増大は確認できなかった。XRD、EDXによりAlのZnF_2中への固溶は確認されており、導入された電子は何らかの欠陥にトラップされ、キャリアを生成していないと推察した。真空中でのアニールなどによるドーパントの活性化が必要である。H^+のイオン注入によるキャリアドープも試みたが、伝導性の大きな変化は認められなかった。
Establishment of basics of nanocrystals growth science and its application to achieve bright quantum dot phosphors

OMATA Takahisa, YOSHIYA Masato

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Osaka University

2008 - 2010

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ZnSe quantum dots were synthesized by a hot-soap method, and the mechanism of the ligand-dependent phase determination was studied by using the oreic acid and oleylamine as complex ligands for zinc acetate. In the case of high supersaturation during the nucleation, the stable zincblende type ZnSe appears, while the metastable wurtzite type ZnSe appears in the case of low supersaturation during the nucleation. During the crystal growth period, no phase transformation depending on the supersaturation level occurs. Thus, it was shown that the phase appeared was determined during the nucleation period, and the complex ligand controls the supersuturation level.
イオニクスナノ結晶をアッセンブルしたナノコンポジット反応場

小俣孝久

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特定領域研究

Institution: 大阪大学

2007 - 2008

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1. メゾポーラスCeO_2ナノ結晶の作製 (NH_4)_2Ce(NO_3)_6水溶液にアンモニア水を加えCeO_2ナノ結晶を作製し、それをPEO-PPO-PEOブロックコポリマー(P123)のエタノール溶液と混合し前駆体溶液とした。シリカガラス基板上に前駆体溶液をスピンコートし乾燥後、500℃で焼成した。作製した薄膜では、CuKa線を用いたときに2q〜0.5°および0.9°付近にメソ孔の規則配列に起因する回折線が観測された。解析の結果、薄膜中ではメソ孔がCubicに規則配列したメソポーラス構造を有することが明らかとなった。広角領域のX線回折から、CeO2の粒径は約7nmであることが示された。昨年度のTEM観察の結果とあわせ、孔径約15nmのcubic型のメゾポーラスCeO2薄膜の作製に成功した。Ptコロイドとの複合化により、CeO2-Pt複合体からなるメソポーラス薄膜の作製を検討した。 2. YSZおよびYDCナノ結晶の表面改質と緻密化代表者らがこれまで研究してきたホットソープ法では、結晶性の良いYSZ、YDCナノ結晶が合成できるが、その表一面がオレイルアミン(OLA)により覆われている。ナノイオニクス特性の研究に用いるために、表面OLAの除去と、ナノ結晶の超高圧プレスによる緻密化を検討した。YSZナノ結晶は800℃以下では粒成長が起こらなかった。酸素中650℃での熱処理によりOLAを酸化除去した粒径5nmのナノ結晶を得られた。得られたナノ結晶を6GPa、600℃で超高圧プレスした。プレス後試料は黒く着色し、砕けていた。ラマンスペクトルの解析から、プレスによって高圧相への相転移が生じたと推察された。YDCナノ結晶を過酸化水素水とともに密閉容器に入れ、200℃で3時間オートクレーブ処理することによってOLAを低減できることが見出された。
Synthesis of Semicenductor Quantum Dots Phosphors and Their Application for the Elecnoluminescence Devices

OMATA Takahisa

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Osaka University

2006 - 2007

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1. Synthesis of quantum dots (QDs) CuInS_2 quantum dots with 〜5nm in size were successfully synthesized. The crystal structure of the CuInS_2 QDs, the chalcopyrite-type or the wurtzite-type, was dependent on the amount of the amines and the storage time after addition of amines. The optical absorption edges of the chalcopyrite- and wurtzite-types CuInS_2 QDs obtained were 〜710nm in wavelength. For the chalcopyrite-type CuInS_2, photoluminescence (PL) band at 930nm was observed, and no PL band was observed for the wurtzite-type CuInS_2. The PL band observed for the chalcopyrite-type QDs was attributed to the electron-hole recombination via defect revels. As a result of the further study of the starting solution, we successfully synthesized chalcopyrite-type CuInS_2 QDs with 1.5〜3nm sizes by controlling of the reaction time. For the CuInSe_2 QDs, the increase in PL intensity and the blue shift of the PL wavelength were observed by annealing in oleylamine at 200〜300℃. The changes in the PL properties were related to the increase in the crystallinity of the QDs. 2. Improving the PL properties The PL band near optical absorption edge was newly appeared by overcoating of the CuInS_2 QDs by ZnS thin layer. The PL band may be attributable to the exciton recombination. In this experiment, the QDs used was 〜5nm in size. When the QDs with 2〜3nm in size are overcoated by ZnS, the blue PL may be realized. 3. Fabrication of the QDs thin films and electroluminescence devices By using the ZnS-CuInS_2 alloyed QDs collidal solution as a starting solution, the QDs thin film on the glass substrate, which showed significant PL, was successfully fabricated by electro-spraying. We also fabricated the multilayered EL-device structure, such as glass/ITO/Al_2O_3/QDs-film/Al_2O_3/Al. However, we could not observe any electroluminescence from the device.
コア/シェル複合構造をもつ単分散ナノ結晶からなるシナジーイオニクスの創製

小俣孝久

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特定領域研究

Institution: 大阪大学

2005 - 2006

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(1)ドープしたCeO_2およびZrO_2ナノ結晶の合成セリウムイソプロポキシドとCeBr_3,SmCl_3,GdCl_3との脱ハロゲン化アルキル反応を、オレイルアミンを溶媒および界面活性剤とした溶液中、250℃,30minの条件で行なった。ドープ量の増加に伴い格子定数が増大したこと、Sm203よりもGd203ドープした試料の格子定数が大きかったことから、CeO2ナノ結晶でのドーピングに成功したと結論できた。ナノ結晶中のドーパント濃度は15〜35%、粒径は2.0〜2.3nmであった。ジルコニウムイソプロポキシドとZrCl_4,YCl_3,Gal3との脱ハロゲン化アルキル反応を行なった。反応条件は340℃,1hとした。YCl3を添加した場合、生成物中のY濃度の増大に伴い格子定数は増大し、Gal3を添加した場合は格子定数が減少した。これらより、ZrO2へのドーピングは成功していると結論できた。ドーパントの濃度は10〜35%、粒径は1.2〜2.2nmであった。 (2)CeO_2/ZrO_2コア/シェル複合ナノ結晶のキャラクタリゼーション前年度の研究で得られた、CeO_2/ZrO_2コア/シェル複合ナノ結晶のXPSを解析した結果、CeO_2はナノ粒子の内部にあり、表面はZrO_2に覆われていることを明らかにした。 (3)CeO_2/ZrO_2コア/シェル複合ナノ結晶の低温焼結に関する研究コア/シェル型CeO_2/ZrO_2ナノ結晶の粉末を空気中,200〜500℃の各温度でそれぞれ5時間後アニールした。400および500℃での加熱後のXRDはシャープな回折線からなり、加熱によりコアのCeO_2とシェルのZrO_2が界面で反応し、CeO_2-ZrO_2固溶体を生成したことが示された。コア/シェル複合ナノ構造を維持したバルク体の作製には、400以下の低温でかつGPaオーダーの超高圧下での緻密化により達成されるであろうことが示された。
High efficient charges separation-type photo-electrode with controlled energy band-bending

MATSUO Shinya, OMATA Takahisa, UEDA Masato

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Osaka University

2004 - 2006

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An energy band-bending induced by homo-and hetero-junctions of semiconductors must be a key factor for attainment of efficient hydrogen production via photo-electrode water splitting. In the present study, composites of TiO_2 with donor-doped titanate, Sr(Ti_<1x>Nb_x)O_<3+5> in states of powder, single crystal and thin film, were prepared, and various pysico-chemical phenomena, i.e., photo-bleaching of dyes, water splitting photo-reaction, dye-sensitized photo-current, and ions adsorption, were investigated. (1) Photobleaching of methylene blue aqueous solution sensitized with Sr(Ti_<1-x>Nb_x)O_<3+δ>/ TiO_2 composite powders proceeded several time faster than that with TiO_2 alone. Strong adsorption of MB on the powder was observed. This revealed spatial separation of photo-excited charges near the junction. (2) When Sr(Ti_<0.98>Nb_<0.02>)O_<3+δ> single crystal plate covered by TiO_2 thin film was used as a photo-electrode, the photo-current was larger 1.5 or 2 times than that for glass plate with FTO thin film covered by TiO_2 thin film. The TiO_2 thin film was prepared by sol-gel method. (When mono-light was irradiated, on-set wavelength for Sr(Ti_<0.98>Nb_<0.02>)O_<3+δ> single crystal / TiO_2 was shifted toward shorter wavelength 20 nm (0.1 eV) than that for FTO glass plate / TiO_2. (3)This proved the existence of spike in the heterojunction, end therefore this confirms the appearance of band-bending due to heterjunction. (4)The preparation of Sr(Ti_<i-x>Nb_5)O_<3+5>/ TiO_2 junction on the Ti-based alloy plates and controlling of ion adsorption on the composite powder were examined. (5) The controlling of the ion species adsorbed on the electrode must become important for photo-electrochemical reaction. The findings described above should be applied for highly efficient photo-electrochemical water splitting
Building up of concerted electronic material possessing hybridized conduction band

OMATA Takahisa, MATSUO Shinya

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Osaka University

2003 - 2005

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In this project, we have attempted to design and synthesize novel materials in which the bottom of the conduction band consists of hybridization between s- and d-bands or s- and f -bands. These materials are termed "hybridized conduction-band materials" in this project. The elucidation of the energy band structure, electron doping and searching of novel properties under strong magnetic field have been carried out for these materials. By oxidation of precursor pyrochlore-type oxide of Sn^<II>_2M^V_2O_7 (MV=Nb, Ta) at 〜673K, novel metastable oxides of Sn^<IV>M^VO_<4+x>, in which the cations of Sn^<IV> and M^V were respectively ordered similar manor observed in the precursor pyrochlore structure, were successfully synthesized. The energy of Sn 5s and Nb 4d or Ta 5d orbital was very close in these oxides. The crystal structure of these oxides was elucidated by Rietveld analysis using XRD, and the transformation mechanism has been proposed based on the crystal chemistry. For the SnTaO4+x and CeSnO4, in which the energy of Ce 4f and Sn5s are very close, the electron doping by generation of oxygen vacancies, which were induced by annealing the samples under diluted hydrogen atmosphere, became successful. For instance, we have succeeded to synthesize hybridized conduction-band materials. The electrical conductivity of the SnTaO_<4+x> and CeSnO_4 were measured under strong magnetic field of 7T on a quest to finding out of novel properties such as magnetoresistance. However, we could not find out unfortunately. It was inferred that the hybridization between Sn 5s and Ta 5d or Sn 5s and Ce 4f is insufficient in the present materials. The oxygen release from fluorite related SnTaO_<4+x> was started at very low temperature of 670K under reducing atmosphere, while the α-PbO_2 type SnTaO_<4+x> was start reducing at comparatively high temperature of 820K. Such a property is available for the oxygen storage material in exhaust gas cleaning. It was shown that the hybridized conduction band materials synthesized in the present project show distinctive properties in chemical property.
複合酸化物中で安定に共存する電子・正孔捕獲欠陥とその光化学応用

小俣孝久

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 奨励研究(A)

Institution: 大阪大学

2000 - 2001

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昨年度までの研究により、パイロクロア型およびペロブスカイト型の高温プロトン導電体では、電子捕獲欠陥と正孔捕獲欠陥が共存していること、それらの欠陥に由来する光吸収帯の強度はパイロクロア型プロトン導電体よりもペロブスカイト型プロトン導電体の方が強いことなどが明らかとなっていた。本年度は、光化学応用の一例として、その光触媒作用を中心に検討した。実験は、強い光吸収帯をもつペロブスカイト型プロトン導電体で行った。光触媒活性は、キセノンランプ光を照射した際のメチレンブルー水溶液の光ブリーチングと水の酸素と水素への分解により評価した。その結果、CaZrO_3やSrZrO_3をベースにしたプロトン導電体では、光触媒活性は非常に小さかったが、エネルギーバンドギャップが5eV程度であることを考慮すると、欠陥準位を介した電子励起が関わっている兆候であるといえた。SrCeO_3をベースにしたプロトン導電体では、僅かではあるが水の分解が検出できた。SrCeO_3はもともとのエネルギーバンドギャップが可視域にあったので、SrCeO_3をベースにしたプロトン導電体で観測された光触媒活性は、電子・正孔捕獲欠陥を介した光励起によって生成した電子と正孔ではなく、バンド間遷移により生成した電子と正孔が光触媒反応に関わったに違いない。一連の実験結果を以下のように総括した。高温プロトン導電体では電子捕獲欠陥と正孔捕獲欠陥が安定に共存した。それらの欠陥準位を介した励起は、光触媒反応のような化学反応に関与する電子と正孔となりうる。欠陥の積極的な利用により、光化学的応用の新たな展開が開けるに違いない。より高濃度にそれら欠陥が存在する物質の探索が望まれる。
Novel physical property induced by a construction of organic cell-type ceramics

OTSUKA-YAO-MATSUO Shinya, IZU Noriya, OMATA Takahisa

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A).

Institution: Osaka University

1998 - 2000

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Pyrochlore-type oxide La_2Zr_2O_7 doped with Ca^<2+>, Sr^<2+>, Ba^<2+> on its A and B sites, respectively, dissolves proton ; however, the reaction for the dissolution may be different on the point of positive hole depletion. In the present study, the oxides doped with Ca^<2+> on its A and B sites, respectively, annealed under the H_2O and D_2O gases, respectively, were subjected to infrared spectroscopic analysis. For the A-site displaced sample with H_2O treatment, three sharp peaks were observed around 3500 cm^<-1> ; the result was completely different from that for the perovskite-type oxides exhibiting a broad spine which are well known as proton conductor at high temperatures. When done with D_2O treatment, the peaks was shifted toward a lower wave number, i.e., 2500 cm^<-1>, keeping the shape of the peaks. It could be concluded that the spectra detected came from the dissolved proton. For the B-site displaced sample, more than 6 peaks appeared. Dependence of the spectrum strength on the water vapor pressure differed obviously between the A-site and B-site displacements. These results have revealed that the mechanism of the proton dissolution are different, i.e., on the point of the positive hole depletion. When the water vapor pressure of the atmosphere was changed, the difference may induce a voltage for the junction of the A-site and B-site displaced oxides. We could confirmed the junction voltage experimentally. Thus, using the mixtures of the A-site and B-site displaced oxides powders, which we call organic cell-type ceramics, we tried the NO_2 decomposition based on the internal voltage induced. An quadruple-pole mass spectrometry was used to measure the NO_2 concentration, evacuating the system ; however, the leak of the system could not be neglected. The final objective of the present works was to construct organic cell-type ceramics by mixing the powders and utilizing the internal voltage among the cell, i.e., boundary, to decompose the NO_x gas. To attain the important subject, improvement on the production way of the fine oxides powder, possibly together with platinum powder, and also the detection technique of NO_x gas have been needed.
ドナードープしたC希土構造酸化物中の格子間酸素による電荷補償機構の研究

小俣孝久

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 奨励研究(A)

Institution: 大阪大学

1998 - 1999

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1.光吸収スペクトルの評価・解析 (1)昨年度Er^<3+>をドープしたIn_2O_3とITOの焼結体粉末で得られたせいかの理論的な裏づけを得るため、それらの薄膜に対する低温での光吸収スペクトルの測定を予定していた。しかしながら、Er^<3+>を薄膜中にドープすることが出来ず、これについては今のところの成功していない。 (2)希土類イオンの光による電子遷移の強度に関するJudd-Ofelt理論によると、^4I_<15/2>→^2H_<11/2>の遷移は、ゼロでないU^<(2)>行列要素がある。そのような遷移では、希土類イオンの配位環境に敏感なΩ_2パラメータによって強度が大きく変わる。Er^<3+>ドープしたITOとIn_2O_3の粉末の光吸収スペクトルで見られた差は、そられの間でのΩ_2パラメータの違いを反映したものと結論された。 2.研究総括 (1)大気中で作製されたITOの密度は、電子を2個トラップした格子間酸素の存在によって解釈できる。 (2)Er^<3+>イオンをプローブイオンとしてドープしたIn_2O_3、ITOの多結晶粉末の^4I_<15/2>→^2H_<11/2>のf-f電子遷移に帰属される光吸収(約522nm)は、In_2O_3とITOとで大きな差異があることを見出した。その起源は、Sn^<4+>ドープによってC希土構造中に過剰酸素が持ち込まれ、陽イオンの配位数が増加したことであると結論された。さらに、この光吸収スペクトルの強度変化は、Judd-Ofeltの理論によって解釈できた。 (3)格子間酸素による電荷の補償を考慮し、ITOのSn^<4+>のドーピングの機構を次の欠陥反応式で表せる。2SnO_2→2Sn_<In> +2(1-z)e'+zO_i"+ 3O^×_o+(1-z)/2O_2(gas)
SOLID IONIC PROPERTIES OF METASTABLE ZrO_2-CeO_2-CeO_<1.5> SOLID SOLUTIONS

MATSUO Shinya, KIMURA Hideo, IZU Noriya, OMATA Takahisa

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Osaka University

1997 - 1998

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In the metal-oxygen system, reduction and successive oxidation of a single phase make possible to prepare various metastable phases ; the oxidation proceeds remaining the cation distribution in the precursor of reduced phase. This principle was applied to ZrO_2 - CeO_2 system, the local atom displacements and solid ionics properties of the noble metastable phases obtained were characterized The precursors were prepared by reducing the t'-(Ge_<0.5>Zr_<0.5>O_2) phase at T_<de>=873K-1573K.When the precursor with T_<de>=1573K was oxidized at 873 K, a noble metastable kappa-CeZiO_4 phas was obtained in which Ce and Zr are in an ordered arrangement. The oxidation of the precursor with 1173K produced another noble metastable t'_<meta>, -(Ce_<0.5>Z_<0.5>O_2) phase in which Ce and Zr are in an disordered arrangement similar to t'-(Ce_<0.5>, Zr_<0.5>O_2). The distance between Ce-O-Ce ions decreased in the order of t'* t'_<meta> * kappa. In spite of the same composition : CeZrO_4, the electrical conductivity of the metastable t'_<meta> and kappa phases were found to be fairly larger than that of t'. The results couled be interpreted in terms of the Ce-O-Ce distance, cation distribution, and oxygen displacement. The present results imply that the electrical properties could be controlled by the preparation of metastable phase as well as doping of impurities.
層状ペロブスカイト類似構造を持つクロム、コバルト複合酸化物の熱電能に関する研究

小俣孝久

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 奨励研究(A)

Institution: 大阪大学

1996 - 1996

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La,Sr,Cr及びCoの各酸化物,炭酸塩を出発原料として、1100〜1500℃での固相反応により、La_<2-x>Sr_xCrO_4(1.0≦x≦1.3)およびLa_<2-x>Sr_xCoO_4(0≦x≦1.2)を合成した。仮焼粉末を1〜1.5GPaでCIP成形することにより、相対密度85〜98%の焼結体を合成した。La_<2-x>Sr_xCrO_4(1.0≦x≦1.3)の室温における電気伝導度は10^<-1>S・m^<-1>(x=1.0)から10^1S・m^<-1>(x=1.3)へとSrドープにより増加した。これらの室温〜77Kでの電気伝導度は温度の-1/4乗に比例しvariable range hopping(VRH)伝導で記述できた。また、室温における熱起電力は、343μVK^<-1>(x=1.0)から89μVK^<-1>(x=1.3)へとSrド-ピングにより減少した。VRHモデルによれば、熱起電力は温度の1/2乗に比例する。これより、La_<2-x>Sr_xCrO_4の熱起電力は、室温以上の高温でより大きくなると推測した。室温〜300℃で熱起電力を測定した結果、この温度域での熱起電力は室温の値とほぼ同じであり、温度依存性は見られなかった。そこで、同じ温度範囲での電気伝導度を測定した。その結果、La_<2-x>Sr_xCrO_4の電気伝導度の温度依存性は、100℃付近を境にVRH機構から、通常のホッピング機構かもしくはバンド伝導的な機構に変化していることがわかった。また、VRH伝導機構で記述できる室温〜100℃間の熱起電力に差がないことから次を考察した。VRH伝導の熱起電力の温度依存性は、温度の1/2乗に比例しまた、伝導を担う不純物状態の局在半径の逆数の3乗に比例する。室温〜100℃間の熱起電力に温度依存性が見えなかったのは、不純物状態の局在半径が増大し、それが温度上昇の効果を相殺したためと推測する。La_<2-x>Sr_xCrO_4系のx=1.2では、室温で10^2Sm^<-1>という高い電気伝導度と200μVK^<-1>という大きな熱起電力を観測した。
New Microwave Dielectric Ceramics of Zirconium Titanate Solid Solutions

IKAWA Hiroyuki, TAKEMOTO Minoru, OMATA Takahisa

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Kanagawa Institute of Technology

1995 - 1996

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Microwave Dielectric Properties of Zr_xHf_yTi_zO_4 (x+y+z=2) Solid Solution Ceramics This research aimed at developing a microwave dielectric ceramics of the title composition having a high Q-value. High purities raw materials were used for this purpose, further, examined processings were a co-precipitation method and solid state reaction methods. The f・Q values measured in this study ranged from 14 to 19 THz, which were not hihg enough for this experiment. The value is expected to increase by choosing a slower cooling rate after sintering. Although there were some inconsistency, the relative permittivity was estimated to increase with increasing Ti content (z) and/or Zr content. The largest relative permittivity measured in this study was 41.2 for Zr_<0.34>Hf_<0.58>Ti_<1.08>O_4. The compositions were made clear which were tunable to the zero ppm for a temprature coefficient of resonance frequency. Microwave Dielectric Properties of Complex Perovskite A-site of which is Isomorphoologically Substituted epsilon_r of Ba_<1-x>Ca_x (Mg_<1/3>Ta_<2/3>)O_3 and Ba_<1-x>Ca_x (Mg_<0.3>Ta_<0.6>Zr_<0.1>)O_3 increased significantly with x to have peaks near at solubility limits. The pressure coefficient of epsilon_r increased with increasing epsilon_r of the composition.
鉄を含む複合硫化物の電磁気的性質と電子構造の研究

小俣孝久

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 奨励研究(A)

Institution: 神奈川工科大学

1995 - 1995

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La_2Fe_2S_5良質試料の合成を検討した。合成方法は次であり、主に溶融および焼結温度の影響を研究した。(1)出発原料はLa_2S_3およびFeSとした。これらをLa_2Fe_2S_5組成に坪量しめのう乳鉢で混合。(2)混合粉を油拡散ポンプにより10^<-4>Torr以下に排気した石英ガラス管中に封入。(3)電気炉を用いて800〜1200℃で焼結および溶融。(3)の溶融および焼結操作では1100℃以上で溶解し、La_2Fe_2S_5相とLaFeS_<3-δ>相および未同定相が生成した。1100℃未満では、複雑なX線回折パターンを持つ未同定相が生成し、La_2Fe_2S_5相は得られなかった。1100,1125,1150,1175および1200℃の各温度で溶融し、その温度からの急冷および徐冷を行ったが、La_2Fe_2S_5相の単相は得られなかった。また、原料中の硫黄を化学量論組成より1%,2%および5%過剰に添加した原料を出発として同様の操作を行ったが、単相は得られなかった。粉末X線回折図形より、目的物質であるLa_2Fe_2S_5相が最も多く生成した条件は次であった。硫黄過剰添加量1%,1200℃,4h溶融後室温まで急冷。この操作で得られた試料について、4端子法による直流電気伝導度および熱起電力を測定した。室温での伝導度は2.4×10^<-2>Scm^<-1>であり、その温度依存性は半導体的であった。伝導の活性化エネルギーは約0.2eVであった。熱起電力の符号が正であったことから、この物質はp型の半導体であることがわかった。これらのことをまとめて、La_2Fe_2S_5の電子構造は、伝導帯底部を構成するFe3d軌道よりも価電子帯上部を構成するS3p軌道の逆格子空間における分散が大きいと考察した。
Study on Electrorheological Fluids Dispersing Ferroelectrics in the Range of Size Dependence

IKAWA Hiroyuki, OMATA Takahisa, HAYASHI Tsuyoshi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for General Scientific Research (B)

Institution: Kanagawa Institute of Technology

1994 - 1995

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* Electrorhelogical Effects as Functions of Heating Temperatures of Fine Powders of Barium Titanate and Ba_<0.8>Sr_<0.2>TiO_3 The raw fine powders of BaTiO_3 and Ba_<0.8>Sr_<0.2>TiO_3 were hydrothermally synthesized with particle sizes of 0.1mum. The powders were heated at temperatures to thoroughly disperse in silicon oil with a volume ratio of 10%. Electrorheologies of dispersed oils were measured by using a double cylinder rheometer. An interesting result was noted that electrorhelogical effects -the increase in shear stress by applying a dc electric field, 2 kV/mm in this case - took singular peaks for powders heated at specific temperatures. The respective those temperatures for BaTiO_3 and Ba_<0.8>Sr_<0.2>TiO_3 were 700ﾟC and 900ﾟC.The X-ray diffractions revealed that the 200 peaks of those powers were just before 200/002 splittings which were characteristic to ferroelectrics. * Colloid Chemistry of Barium Titanate and Electrorheology of Surface Treated Barium Titanate The zeta -potential of BaTiO_3 dispersed in ethanol was 40 mV.The adsorption of sodium dodecyl sulfate decreased the potential to 16 mV,and sodium alpha-olefin sulfonate decreased it down to minus. BaTiO_3 were mixed with toluene containing poly-buthyl metacrylate. The apparent viscosity of the dispersed oil was 1/5 of that containing non-treated BaTiO_3. However, the ER effect also decreased in half.

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