TOHOKU UNIVERSITY Researchers

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Yuichi Ikuhara

Section

Advanced Institute for Materials Research

Job title

Professor

Degree

Dr. Eng.

researchmap

https://researchmap.jp/ikuhara_yuichi

J-GLOBAL ID

200901062933868498

Research History 12

2017/04 - Present

Tohoku University　Advanced Institute for Materials Research　Principal Investigator, Professor
2012/09 - Present

Kyoto University　Elements Strategy Initiative for Structural Materials　Principal Investigators, Professor
2007/04 - Present

Japan Fine Ceramics Center　Nanostructures Research Lab
2003/01 - Present

The University of Tokyo　The Graduate School of Engineering
2008/04 - 2017/03

Tohoku University　World Primer International Research Center, Advanced Institute for Materials Research
2005/04 - 2008/03

The University of Tokyo　The Graduate School of Engineering Institute of Engineering Innovation
1996/07 - 2003/01

The University of Tokyo　The Graduate School of Engineering
1995/07 - 1996/06

Japan Fine Ceramics Center
1993/07 - 1995/06

Japan Fine Ceramics Center
1993/04 - 1993/07

Japan Fine Ceramics Center
1991/07 - 1993/03

Case Western Reserve University　Visiting Assistant Professor
1988/07 - 1993/03

Japan Fine Ceramics Center

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Education 2

Kyushu University　The Interdisciplinary Graduate School of Engineering Sciences　The Department of Materials Science and Technology

1983/04 - 1988/03
Kyushu University　School of Engineering　Department of iron and steel Metallurgy

1979/04 - 1988/03

Professional Memberships 8

米国セラミックス学会
日本電子顕微鏡学会
日本金属学会
日本セラミックス協会
Japanese Society of Electron Microscopy
Japan Institute of Metals
Ceramic Society Japan
American Ceramics Society

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Research Interests 8

電子顕微鏡
界面
粒界
セラミックス
Electron Microscopy
Interface
Grain Boundary
Ceramics

Research Areas 2

Nanotechnology/Materials / Structural and functional materials /
Informatics / Computational science /

Awards 28

学士院賞

2023/05　日本学士院
Best Teaching Award 2019

2019/03　School of Engineering, The University of Tokyo
FY2019 Dean’s Award

2019/02　School of Engineering, The University of Tokyo
The 2018 Hatsujiro Hashimoto Medal

2018/09　International Federation of Societies for Microscopy
2017 Hattori Hoko Award

2017/10　The Hattori Hokokai Foundation　"Development of super high-resolution microscopy for direct atomic imaging, and study on controlling atomic structure of interfaces and dislocations"
Medal with Purple Ribbon

2016/11　Cabinet Office, Government of Japan　Achievements in materials science research
CerSJ Fellow Awards

2016/06　The Ceramic Society of Japan
Honorary Professor of East China Normal University

2016/04　East China Normal University
2015 Robert B. Sosman Lecture

2015/10　The American Ceramic Society　"Grain Boundary Segregation, Vacancies and Properties in Oxide Ceramics"
Weatherly Distinguished Lecturer

2015/05　The Microscopical Society of Canada　"In appreciation of his contribution to the electron microscopy of interface"
54th Tanikawa-Harris Award, The Japan Institute of Metals and Materials, 2015

2015/03　The Japan Institute of Metals and Materials
Academician

2014/06　World Academy of Ceramics
Commendation for Science and Technology by the Minister of Education、Culture、Sports、Science and Technology

2013/04　Minister of Education, Culture, Sports, Science and Technology
Fellows of The American Ceramic Society

2011/06　The American Ceramic Society
The Humboldt Research Award

2011/03　Die Alexander von Humboldt-Stiftung　Production and properties of functional materials
2010 Lee Hsun (Li Xun) Lecture Award

2010/11　The Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS)　Atomic Structures and Properties of Ceramic Interfaces Combination of Cs-corrected STEM and First Principles Calculations
The 7th Honda Frontier Award

2010/05　Honda Memorial Foundation
Cosslett Award- Best Invites Paper, Microbeam Analysis Society

2007/08　Microbeam Analysis Society　"Observing Impurity Doping in Oxide Grain Boundaries Using STEM"
the 52nd Seto Award of the Japanese Society of Microscopy, 2007

2007/05　The Japanese Society of Microscopy
The 7th Japan Institute of Metals and Materials Distinguished Contribution Award

2006/03　The Japan Institute of Metals and Materials
2002 Richard M. Fulrath Award by The American Ceramic Society

2002　The American Ceramic Society
55th CerSJ Awards for academic achievements in ceramic science and technology

2001/05　The Ceramic Society of Japan
The 59th Japan Institute of Metals and Materials Meritorious Award

2001/03　The Japan Institute of Metals and Materials
18th Murakami Research Encouragement Prize

1998/06　Murakami Memorial Foundation
1997 Academic Encouragement Award, The Society of Materials Science, Japan

1997　The Society of Materials Science, Japan
JFCC Best Research Award

1991/06　Japan Fine Ceramics Center
11th Honda Memorial Young Researcher Award

1990/05　The Honda Memorial Foundation
村上奨励賞(1998)

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Papers 647

Structural transition and the effect of Ca impurities in MgO Σ5(210) grain boundary

Qian Chen, Mitsuhiro Saito, Kazuaki Kawahara, Atsutomo Nakamura, Kazutoshi Inoue, Yuichi Ikuhara

Journal of the European Ceramic Society　46　(6)　118068-118068　2026/06
Publisher: Elsevier BV
DOI： 10.1016/j.jeurceramsoc.2025.118068 　

ISSN： 0955-2219
Thermal Conductivities of Fluorite Ln O ₂ and Bixbyite Ln ₂ O ₃ Epitaxial Films ( Ln = Ce, Pr, and Tb)

Mitsuki Yoshimura, Ahrong Jeong, Jason Tam, Bin Feng, Yuichi Ikuhara, Kwanhong Park, Jaekwang Lee, Hiromichi Ohta

Journal of the American Ceramic Society　109　(3)　2026/03/03
Publisher: Wiley
DOI： 10.1111/jace.70627 　

ISSN： 0002-7820

eISSN： 1551-2916

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ABSTRACT CeO ₂₋ _δ (0 ≤ δ ≤ 0.5) has attracted attention as an active material for electrochemical thermal switches that control heat flow electrically because of its wide thermal conductivity ( κ ) switching width between CeO ₂ with fluorite structure (12.5 W m ⁻¹ K ⁻¹ ) and Ce ₂ O ₃ with bixbyite structure (2.2 W m ⁻¹ K ⁻¹ ). Although understanding κ of structurally analogous oxides Ln O ₂ and Ln ₂ O ₃ ( Ln = Pr and Tb) is useful for the selection of active materials for thermal switches, κ of Ln O ₂ and Ln ₂ O ₃ has not been reported due to the lack of single‐phase crystals. In this study, we fabricated Ln O ₂ and Ln ₂ O ₃ ( Ln = Ce, Pr, and Tb) epitaxial films by pulsed laser deposition followed by the electrochemical redox control and measured the κ by time‐domain thermoreflectance method. The oxidized PrO ₂ exhibits markedly lower κ (5.2 W m ⁻¹ K ⁻¹ ) than CeO ₂ or TbO ₂ (10.0 W m ⁻¹ K ⁻¹ ). By comparison, the reduced Pr ₂ O ₃ and Tb ₂ O ₃ display comparable κ values, whereas reduced CeO _x remains multiphase with a slightly lower κ . First‐principles calculation results support the observed κ well. Since the specific heat capacities and densities among these oxides are similar, the present results indicate that the thermal diffusivity of PrO ₂ is intrinsically lower than CeO ₂ or TbO ₂ .
Decomposition Behavior of a Thermoelectric Oxide at High-Temperatures and Its Impact on the Thermoelectric Properties International-journal International-coauthorship Peer-reviewed

Kungwan Kang, Yuqiao Zhang, Jingyuan Yan, Chuchu Yang, Bin Feng, Naoya Shibata, Yuichi Ikuhara, Ahrong Jeong, Hiromichi Ohta

ACS Applied Energy Materials　2026/02/09

DOI： 10.1021/acsaem.5c03826 　
Switchable Polarization in an A-Site Deficient Perovskite through Vacancy and Cation Engineering

Suguru Yoshida, Olivier Hernandez, Jinsuke Miyake, Kei Nakayama, Ryo Ishikawa, Hajime Hojo, Yuichi Ikuhara, Venkatraman Gopalan, Katsuhisa Tanaka, Koji Fujita

Journal of the American Chemical Society　2026/01/23
Publisher: American Chemical Society (ACS)
DOI： 10.1021/jacs.5c19790 　

ISSN： 0002-7863

eISSN： 1520-5126
In situ Electron Microscopic Observation of Electrochemical Reactions in Liquid Electrolytes

Kaname Yoshida, Yuki Sasaki, Akihide Kuwabara, Yuichi Ikuhara

Materia Japan　65　(1)　29-29　2026/01/01
Publisher: Japan Institute of Metals
DOI： 10.2320/materia.65.29 　

ISSN： 1340-2625

eISSN： 1884-5843
Improving low-temperature degradation resistance in 3-mol% yttria-stabilized zirconia by flash sintering

Fei Shen Ong, Kenta Kawamura, Kohei Hosoi, Hiroshi Masuda, Bin Feng, Koji Matsui, Yuichi Ikuhara, Hidehiro Yoshida

Ceramics International　2025/12
Publisher: Elsevier BV
DOI： 10.1016/j.ceramint.2025.12.479 　

ISSN： 0272-8842
LaCu5 intermetallic alloy cathode for fluoride-ion batteries

Shun Sasano, Ryo Ishikawa, Kazuaki Kawahara, Naoya Shibata, Yuichi Ikuhara

Journal of Power Sources　658　238294-238294　2025/12
Publisher: Elsevier BV
DOI： 10.1016/j.jpowsour.2025.238294 　

ISSN： 0378-7753
Dopant diffusion and segregation of iron in a near 45° (100) twist grain boundary in SrTiO ₃

William Hahn, Kazuaki Kawahara, Shun Sasano, Bin Feng, Naoya Shibata, Yuichi Ikuhara, Klaus van Benthem

Journal of the American Ceramic Society　109　(1)　2025/10/24
Publisher: Wiley
DOI： 10.1111/jace.70312 　

ISSN： 0002-7820

eISSN： 1551-2916

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Abstract Dopant segregation is a key contributor to interfacial stability and the macroscopic physical properties of polycrystalline materials. Near 45° (100) twist grain boundaries were diffusion bonded either from Fe‐doped SrTiO ₃ single crystals, or nominally undoped single crystals after a thin film of iron was deposited onto the single crystal surface prior to diffusion bonding. After diffusion bonding, scanning transmission electron microscopy characterization detected increased Fe signals from the grain boundary cores of both types of bicrystals. Fe enrichment occurred either by segregation from the doped single crystals or by dopant out‐diffusion into the bulk away from the deposited layer. Quantitative energy dispersive X‐ray spectroscopy experiments identified that the grain boundary prepared after Fe deposition was characterized by much higher dopant enrichment compared to the case after diffusion bonding of two doped single crystals. Additional thermal annealing of the bicrystal formed after iron layer deposition caused a decrease in iron enrichment approaching the excess observed for the diffusion‐bonded doped single crystals. The experimental results demonstrate that, dependent on the method of doping, extended thermal annealing of bicrystals may be necessary after diffusion bonding to achieve equilibrium grain boundary excess quantities.
Atomic and electronic structure of stacking faults on the {11¯02}$\{ {1\bar 102} \}$ plane in 4H‐SiC

Eita Tochigi, Hirofumi Matsuhata, Yuichi Ikuhara

Journal of the American Ceramic Society　2025/09/27
Publisher: Wiley
DOI： 10.1111/jace.70269 　

ISSN： 0002-7820

eISSN： 1551-2916

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Abstract 4H‐SiC epitaxial layers often contain an extended defect called “carrot”, which is considered to consist of three partial dislocations and two stacking faults on the basal and prismatic planes. However, the atomic and electronic structures of the prismatic fault have not yet been revealed. In this study, the prismatic fault was characterized by transmission electron microscopy (TEM) and first‐principles calculations. TEM observations showed that the prismatic fault is composed of stacking faults on the and planes in a zigzag pattern. Theoretical calculations based on experimental results revealed that the fault vector of the stacking fault is . This stacking fault generates some defect levels within the bandgap of 4H‐SiC, which are associated with trigonal planar atomic configurations formed by the stacking fault.
Role of electrode configurations in flash sintering of 3-mol% yttria-stabilized zirconia across varying sample sizes

Fei Shen Ong, Kenta Kawamura, Kohei Hosoi, Hiroshi Masuda, Bin Feng, Koji Matsui, Yuichi Ikuhara, Hidehiro Yoshida

Journal of the European Ceramic Society　117660-117660　2025/07
Publisher: Elsevier BV
DOI： 10.1016/j.jeurceramsoc.2025.117660 　

ISSN： 0955-2219
Real-space observation of polarization induced charges at nanoscale ferroelectric interfaces

Takehito Seki, Toshihiro Futazuka, Scott D Findlay, Naoya Shibata, Masaya Takamoto, Satoko Toyama, Yuichi Ikuhara

Science Advances　2025/06/13

DOI： 10.1126/sciadv.adu8021 　
Atomic-scale observation of Σ5{310} and Σ9{411} grain boundaries in silicon steel

Toshihiro Futazuka, Masaki Arai, Takehito Seki, Ryo Matsubara, Nobusato Morishige, Yuichi Ikuhara, Naoya Shibata

Journal of Materials Science　2025/04/03
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/s10853-025-10770-4 　

ISSN： 0022-2461

eISSN： 1573-4803

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Abstract Grain boundaries (GBs) play a significant role in the formation of coarse-grained texture of silicon steels. Recently, an unusual GB atomic structure has been found in Σ9{221} GB in silicon steel, where the structure is incommensurate with the bulk crystal structure and structural fluctuation may be present due to the phason mode of the incommensurate structure. This new finding evokes the necessity of atomic-scale structural analysis of GBs in silicon steel for other orientation GBs. In this study, we characterized the atomic structure of Σ5{310} and Σ9{411} GBs in silicon steel using magnetic-field-free atomic resolution scanning transmission electron microscopy and theoretical calculation. We have revealed that the observed GB structures matched the previous theoretical predictions. We suggest that the low GB excess and the distorted local atomic structures may be the key factors for the formation of incommensurate GB structures.
Relaxation mechanism of interfacial lattice misfit between PZT and SRO in a thin-film actuator

Shinsuke Hashimoto, Shun Kondo, Takehito Seki, Yuichi Ikuhara, Naoya Shibata

Journal of the Ceramic Society of Japan　133　(4)　105-111　2025/04/01
Publisher: Ceramic Society of Japan
DOI： 10.2109/jcersj2.24111 　

ISSN： 1882-0743

eISSN： 1348-6535
Low‐furnace‐temperature flash sintering of tetragonal 1.5‐mol% YSZ: Role of particle necking on grain growth

Fei Shen Ong, Kenta Kawamura, Kohei Hosoi, Hiroshi Masuda, Bin Feng, Koji Matsui, Yuichi Ikuhara, Hidehiro Yoshida

Journal of the American Ceramic Society　108　(7)　2025/03/19
Publisher: Wiley
DOI： 10.1111/jace.20490 　

ISSN： 0002-7820

eISSN： 1551-2916

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Abstract This study presents a strategy to achieve over 99% relative density in monophasic tetragonal 1.5‐mol% yttria‐stabilized zirconia (1.5YSZ) polycrystalline ceramics via current‐ramp flash (CRF) sintering at furnace temperatures as low as 600°C. While 1.5YSZ exhibits high toughness, it is prone to cracking due to spontaneous tetragonal‐to‐monoclinic (T → M) phase transformation when grain sizes exceed a critical threshold. The proposed strategy combines preheating with multi‐step CRF sintering, where preheating promotes particle neck growth, a key mechanism enabling flash sintering at lower furnace temperatures. Without preheating, flash sintering at furnace temperatures below 1100°C resulted in accelerated grain growth and spontaneous T → M transformation, driven by current localization at poorly developed particle necks. In contrast, incorporating preheating under identical flash sintering conditions reduced grain size by nearly half with minimal change in sample temperature. This strategy lowers furnace temperatures by over 50% compared to conventional sintering methods and significantly accelerates densification. Moreover, it integrates efficiently into existing ceramic manufacturing workflows, which often include calcination to produce moderately dense bodies.
Atomic-scale observations of dislocation junction formation and decomposition processes in gold

Mingen Sou, Shun Kondo, Takaaki Sato, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara

Scripta Materialia　258　116505-116505　2025/03
Publisher: Elsevier BV
DOI： 10.1016/j.scriptamat.2024.116505 　

ISSN： 1359-6462
Direct observations of jog formation and drag caused by screw-screw dislocation interaction

Shun Kondo, Naoya Shibata, Yuichi Ikuhara

Scripta Materialia　258　116513-116513　2025/03
Publisher: Elsevier BV
DOI： 10.1016/j.scriptamat.2024.116513 　

ISSN： 1359-6462
Realizing near-full density monophasic tetragonal 1.5-mol% yttria-stabilized zirconia ceramics via current-ramp flash sintering

Fei Shen Ong, Kohta Nambu, Kenta Kawamura, Kohei Hosoi, Hiroshi Masuda, Bin Feng, Koji Matsui, Yuichi Ikuhara, Hidehiro Yoshida

Acta Materialia　283　2025/01/15

DOI： 10.1016/j.actamat.2024.120496 　

ISSN： 1359-6454
Fluorination of single-crystal copper electrodes in fluoride-ion batteries

Shunsuke Kobayashi, Kazuyuki Sato, Hsin-Hui Huang, Daisaku Yokoe, Takafumi Ogawa, Yuichi Ikuhara, Takeshi Abe, Akihide Kuwabara

Journal of Materials Chemistry A　2025
Publisher: Royal Society of Chemistry (RSC)
DOI： 10.1039/d5ta06729d 　

ISSN： 2050-7488

eISSN： 2050-7496

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We investigated the fluorination process of Cu in fluoride-ion batteries under well-controlled conditions using single-crystal model electrodes, analyzed by electron microscopy.
Capacity enhancement of LaAl₂Ag ternary alloy anode for fluoride-ion batteries

Shun Sasano, Ryo Ishikawa, Kazuaki Kawahara, Naoya Shibata, Yuichi Ikuhara

Journal of Materials Chemistry A　13　(24)　18610-18617　2025
Publisher: Royal Society of Chemistry (RSC)
DOI： 10.1039/d5ta00837a 　

ISSN： 2050-7488

eISSN： 2050-7496

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We demonstrate the LaAl₂Ag ternary alloy as a new anode for fluoride-ion batteries. Compared to pure Al metal and LaAl₃ binary alloy anodes, the LaAl₂Ag anode shows a high reversible capacity of more than 400 mA h g⁻¹ with good cycle stability.
High-performance solid-state electrochemical thermal switches with earth-abundant cerium oxide

Mitsuki Yoshimura, Bin Feng, Ahrong Jeong, Jason Tam, Zhiping Bian, Yasutaka Matsuo, Takashi ENDO, Yuichi Ikuhara, Hiromichi Ohta, Hyeonjun Kong

Science Advances　2025/01/01

DOI： 10.1126/sciadv.ads6137 　
Atomic and electronic structures of inversion domain boundary in MgO doped AlN

D. Kato, B. Feng, T. Nishi, Y. Noritake, T. Hishida, N. Shibata, K. Matsunaga, Y. Ikuhara

Acta Materialia　281　2024/12/01

DOI： 10.1016/j.actamat.2024.120371 　

ISSN： 1359-6454
Direct observation of space-charge-induced electric fields at oxide grain boundaries

Satoko Toyama, Takehito Seki, Bin Feng, Yuichi Ikuhara, Naoya Shibata

Nature Communications　15　(1)　2024/12
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s41467-024-53014-w 　

eISSN： 2041-1723
Ultra-stable and highly reactive colloidal gold nanoparticle catalysts protected using multi-dentate metal oxide nanoclusters Peer-reviewed

Kang Xia, Takafumi Yatabe, Kentaro Yonesato, Soichi Kikkawa, Seiji Yamazoe, Ayako Nakata, Ryo Ishikawa, Naoya Shibata, Yuichi Ikuhara, Kazuya Yamaguchi, Kosuke Suzuki

Nature Communications　15　(1)　2024/12

DOI： 10.1038/s41467-024-45066-9 　

eISSN： 2041-1723
Nanoscale electromagnetic field imaging by advanced differential phase-contrast STEM

Satoko Toyama, Takehito Seki, Yuji Kohno, Yoshiki O. Murakami, Yuichi Ikuhara, Naoya Shibata

Nature Reviews Electrical Engineering　2024/11/26
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s44287-024-00117-7 　

eISSN： 2948-1201
Defect-Engineered Coordination Compound Nanoparticles Based on Prussian Blue Analogues for Surface-Enhanced Raman Spectroscopy International-journal

Xingxing Yu, Xuke Tang, Jun Yu Dong, Yunjie Deng, Mitsuhiro Saito, Zhanglei Gao, Pablo Martinez Pancorbo, Machiko Marumi, Walker Peterson, Huanhuan Zhang, Naoki Kishimoto, Abdullah N. Alodhayb, Prabhat K. Dwivedi, Yuichi Ikuhara, Yasutaka Kitahama, Ting Hui Xiao, Keisuke Goda

ACS Nano　18　(45)　30987-31001　2024/11/12

DOI： 10.1021/acsnano.4c06972 　

ISSN： 1936-0851

eISSN： 1936-086X
La_1−xSrxF_3−x: A Solid-State Electrolyte for Fluoride Ion Battery with High Ionic Conductivity and Wide Electrochemical Potential Window

Kazuaki Kawahara, Ryo Ishikawa, Shun Sasano, Naoya Shibata, Yuichi Ikuhara

Journal of The Electrochemical Society　171　(11)　110508-110508　2024/11/01
Publisher: The Electrochemical Society
DOI： 10.1149/1945-7111/ad8d10 　

ISSN： 0013-4651

eISSN： 1945-7111

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Fluoride ion conductors are developed for use as solid-state electrolytes in fluoride ion batteries which are one of promising candidates for next-generation storage batteries. Ba-doped LaF₃ (La_0.9Ba_0.1F_2.9: LBF) is mainly used as a solid-state electrolyte in fluoride ion batteries. However, room temperature conductivity of LBF is considerably low, on the order of 10⁻⁶ S cm⁻¹ and it is still unclear the optimal elements to be doped to LaF₃. In this study, we have explored La_0.9Sr_xBa_0.1−xF_2.9 system (x = 0, 0.01, 0.025, 0.05, 0.1), in which Ba in LBF is substituted for Sr and investigated the composition dependence of ionic conductivity. We elucidate that the higher concentration of Sr without Ba can significantly improve the ionic conductivity, and the maximum ionic conductivity of La_0.9Sr_0.1F_2.9 is 1.5 × 10⁻⁵ S cm⁻¹ at room temperature, which is one order of magnitude larger than that of LBF. The higher ionic conductivity of LSF is due to the larger grain size and higher sintering density of LSF compared to LBF, which results in lower grain boundary resistance. The LSF total ionic conductivity of 10⁻⁴ S cm⁻¹ can be achieved at 350 K, which significantly lowers operating temperature of fluoride ion batteries down to 350 K.
Atomic resolution observation of zeolitic framework and captured cations using low-dose OBF STEM technique

Kousuke Ooe, Takehito Seki, Koudai Tabata, Kaname Yoshida, Atsushi Nakahira, Yuji Kohno, Yuichi Ikuhara, Naoya Shibata

BIO Web of Conferences　129　07003-07003　2024/10/17
Publisher: EDP Sciences
DOI： 10.1051/bioconf/202412907003 　

eISSN： 2117-4458
In situ microscopic observations of zinc electrodeposition process in various electrolytes

Kaname Yoshida, Yuki Sasaki, Akihide Kuwabara, Yuichi Ikuhara

BIO Web of Conferences　129　25002-25002　2024/10/17
Publisher: EDP Sciences
DOI： 10.1051/bioconf/202412925002 　

eISSN： 2117-4458
Synthesis of a Gold–Silver Alloy Nanocluster within a Ring-Shaped Polyoxometalate and Its Photocatalytic Property

Minori Kamachi, Kentaro Yonesato, Takashi Okazaki, Daiki Yanai, Soichi Kikkawa, Seiji Yamazoe, Ryo Ishikawa, Naoya Shibata, Yuichi Ikuhara, Kazuya Yamaguchi, Kosuke Suzuki

Angewandte Chemie - International Edition　63　(41)　2024/10/07
Publisher: Wiley
DOI： 10.1002/anie.202408358 　

ISSN： 1433-7851

eISSN： 1521-3773
Diffraction contrast of ferroelectric domains in DPC STEM images

Masaya Takamoto, Takehito Seki, Yuichi Ikuhara, Naoya Shibata

Microscopy　73　(5)　422-429　2024/10/01
Publisher: Oxford University Press (OUP)
DOI： 10.1093/jmicro/dfae019 　

ISSN： 2050-5698

eISSN： 2050-5701
Fabrication of 3YSZ with single tetragonal phase by ultrafast high-temperature sintering

Ryuhei Murakami, Bin Feng, Koji Matsui, Shun Kondo, Naoya Shibata, Yuichi Ikuhara

Ceramics International　50　(19)　37308-37313　2024/10/01
Publisher: Elsevier BV
DOI： 10.1016/j.ceramint.2024.04.118 　

ISSN： 0272-8842
Atomic-engineered gradient tunable solid-state metamaterials

Zhiyuan Yan, Albertus Denny Handoko, Weikang Wu, Chuchu Yang, Hao Wang, Meltem Yilmaz, Zhiyong Zhang, Libo Cheng, Xinbin Cheng, Ghim Wei Ho, Bin Feng, Naoya Shibata, Rong Zhao, Joel K.W. Yang, Chong Tow Chong, Yuichi Ikuhara, Cheng Wei Qiu

Proceedings of the National Academy of Sciences of the United States of America　121　(39)　2024/09/24

DOI： 10.1073/pnas.2408974121 　

ISSN： 0027-8424

eISSN： 1091-6490
Comprehensive electrochemical imaging analyses of redox activities correlated to multilayer graphene and graphite structures

Akichika Kumatani, Chiho Miura, Hiroki Ida, Yasufumi Takahashi, Yuichi Ikuhara, Hitoshi Shiku, Tomokazu Matsue, Takeru Okada

Electrochimica Acta　499　144688-144688　2024/09/20
Publisher: Elsevier BV
DOI： 10.1016/j.electacta.2024.144688 　

ISSN： 0013-4686
Real‐Space Tilting Method for Atomic Resolution STEM Imaging of Nanocrystalline Materials

Jiake Wei, Zhangze Xu, Wenjie Shen, Bin Feng, Ryo Ishikawa, Naoya Shibata, Yuichi Ikuhara, Xuedong Bai

Small Methods　2024/09/09
Publisher: Wiley
DOI： 10.1002/smtd.202401023 　

ISSN： 2366-9608

eISSN： 2366-9608
Atomic-Scale and Nanoscale Structural Changes in LiCoO₂ Due to Irreversible Delithiation Accompanied by Oxygen Release

Kei Nakayama, Shunsuke Kobayashi, Ryo Ishikawa, Akihide Kuwabara, Yuichi Ikuhara

Chemistry of Materials　2024/09/05
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.chemmater.4c02084 　

ISSN： 0897-4756

eISSN： 1520-5002
Synthesis of Ultrahigh-Purity (6,5) Carbon Nanotubes Using a Trimetallic Catalyst

Satoru Shiina, Tennpei Murohashi, Koyo Ishibashi, Xing He, Takashi Koretsune, Zheng Liu, Wataru Terashima, Yuichiro K. Kato, Kazutoshi Inoue, Mitsuhiro Saito, Yuichi Ikuhara, Toshiaki Kato

ACS Nano　18　(35)　23979-23990　2024/09/03

DOI： 10.1021/acsnano.4c01475 　

ISSN： 1936-0851

eISSN： 1936-086X
Total third-degree variation for noise reduction in atomic-resolution STEM images

Kazuaki Kawahara, Ryo Ishikawa, Shun Sasano, Naoya Shibata, Yuichi Ikuhara

Microscopy　2024/07/02
Publisher: Oxford University Press (OUP)
DOI： 10.1093/jmicro/dfae031 　

ISSN： 2050-5698

eISSN： 2050-5701

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Abstract Scanning Transmission Electron Microscopy (STEM) enables direct determination of atomic arrangements in materials and devices. However, materials such as battery components are weak for electron beam irradiation, and low electron doses are required to prevent beam-induced damages. Noise removal is thus essential for precise structural analysis of electron-beam-sensitive materials at atomic resolution. Total square variation (TSV) regularization is an algorithm that exhibits high noise removal performance. However, the use of the TSV regularization term leads to significant image blurring and intensity reduction. To address these problems, we here propose a new approach adopting L2 norm regularization based on higher-order total variation. An atomic-resolution STEM image can be approximated as a set of smooth curves represented by quadratic functions. Since the third-degree derivative of any quadratic function is 0, total third-degree variation (TTDV) is suitable for a regularization term. The application of TTDV for denoising the atomic-resolution STEM image of CaF2 observed along the [001] zone axis is shown, where we can clearly see the Ca and F atomic columns without compromising image quality.
Dynamic Observations of Dislocations and Grain Boundaries in Oxides

Yuichi Ikuhara

Microscopy and Microanalysis　30　(Supplement_1)　1049-1050　2024/07/01

DOI： 10.1093/mam/ozae044.517 　

ISSN： 1431-9276

eISSN： 1435-8115
Three-dimensional crystal defect imaging by STEM depth sectioning

Ryo Ishikawa, Naoya Shibata, Yuichi Ikuhara

Chinese Physics B　33　(8)　086101-086101　2024/07/01
Publisher: IOP Publishing
DOI： 10.1088/1674-1056/ad4ff9 　

ISSN： 1674-1056

eISSN： 2058-3834
Reduction of (100)-Faceted CeO<inf>2</inf> for Effective Pt Loading

Akira Yoko, Haodong Wang, Ko Furuya, Daiki Takahashi, Gimyeong Seong, Takaaki Tomai, Anatoly I. Frenkel, Mitsuhiro Saito, Kazutoshi Inoue, Yuichi Ikuhara, Tadafumi Adschiri

Chemistry of Materials　36　(11)　5611-5620　2024/06/11
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.chemmater.4c00627 　

ISSN： 0897-4756

eISSN： 1520-5002
Crystal structures of two new high-pressure oxynitrides with composition SnGe4N4O4, from single-crystal electron diffraction

Philipp Gollé-Leidreiter, Shrikant Bhat, Leonore Wiehl, Qingbo Wen, Peter Kroll, Ryo Ishikawa, Martin Etter, Robert Farla, Yuichi Ikuhara, Ralf Riedel, Ute Kolb

Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials　80　(3)　182-192　2024/06/01
Publisher: International Union of Crystallography (IUCr)
DOI： 10.1107/S2052520624002683 　

ISSN： 2052-5192

eISSN： 2052-5206
Dopant-impurity interactions on grain boundary segregation in alumina

Chuchu Yang, Bin Feng, Jiake Wei, Naoya Shibata, Yuichi Ikuhara

Journal of Materials Science and Technology　181　58-62　2024/05/10
Publisher: Elsevier BV
DOI： 10.1016/j.jmst.2023.08.066 　

ISSN： 1005-0302
Direct Imaging of Atomic Rattling Motion in a Clathrate Compound Peer-reviewed

Koudai Tabata, Takehito Seki, Scott D. Findlay, Ryo Ishikawa, Ryuji Tamura, Yuichi Ikuhara, Naoya Shibata

Small Science　4　(4)　2024/04

DOI： 10.1002/smsc.202300254 　

eISSN： 2688-4046
Applications of electron microscopic observations to electrochemistry in liquid electrolytes for batteries

Kaname Yoshida, Yuki Sasaki, Akihide Kuwabara, Yuichi Ikuhara

Microscopy　73　(2)　154-168　2024/04/01
Publisher: Oxford University Press (OUP)
DOI： 10.1093/jmicro/dfad044 　

ISSN： 2050-5698

eISSN： 2050-5701
Hydrogen-Induced Reduction Improves the Photoelectrocatalytic Performance of Titania

Carlos Sánchez-Sánchez, Roberto Muñoz, Elena Alfonso-González, Mariam Barawi, José I. Martínez, Elena López-Elvira, Gabriel Sánchez-Santolino, Naoya Shibata, Yuichi Ikuhara, Gary J. Ellis, Mar García-Hernández, María Francisca López, Víctor A. de la Peña O’Shea, José A. Martín-Gago

ACS Applied Energy Materials　7　(6)　2101-2108　2024/03/25

DOI： 10.1021/acsaem.3c02707 　

eISSN： 2574-0962
Nanoscale Localized Phonons at Al<inf>2</inf>O<inf>3</inf> Grain Boundaries

Jingyuan Yan, Ruochen Shi, Jiake Wei, Yuehui Li, Ruishi Qi, Mei Wu, Xiaomei Li, Bin Feng, Peng Gao, Naoya Shibata, Yuichi Ikuhara

Nano Letters　24　(11)　3323-3330　2024/03/20
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.nanolett.3c04149 　

ISSN： 1530-6984

eISSN： 1530-6992
Real-time tracking of three-dimensional atomic dynamics of Pt trimer on TiO 2 (110) Peer-reviewed

Ryo Ishikawa, Toshihiro Futazuka, Yu Jimbo, Kazuaki Kawahara, Naoya Shibata, Yuichi Ikuhara

Science Advances　10　(9)　2024/03

DOI： 10.1126/sciadv.adk6501 　

eISSN： 2375-2548
Atomistic Investigation of Grain Boundary Fracture in Alumina

Jingyuan Yan, Shun Kondo, Bin Feng, Naoya Shibata, Yuichi Ikuhara

Nano Letters　24　(10)　3112-3117　2024/02/28
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.nanolett.3c04875 　

ISSN： 1530-6984

eISSN： 1530-6992
The atomic and electronic band structures in Ca/Si-doped and Ca/Si/Ti-doped Al2O3 grain boundaries

Chuchu Yang, Bin Feng, Toshihiro Futazuka, Jiake Wei, Naoya Shibata, Yuichi Ikuhara

Journal of the European Ceramic Society　44　(2)　1005-1011　2024/02
Publisher: Elsevier BV
DOI： 10.1016/j.jeurceramsoc.2023.09.011 　

ISSN： 0955-2219

eISSN： 1873-619X
Mixed anion effects on structural and electrochemical characteristics of Li₄Ti₅O₁₂ for high-rate and durable anode materials Peer-reviewed

Hye-min Kim, Dae-wook Kim, Kenjiro Hara, Hiromasa Shiiba, Youn Charles-Blin, Eugenio Hernán Otal, Hideki Tanaka, Katsuya Teshima, Gabriel Sanchez-Santolino, Ryo Ishikawa, Yuichi Ikuhara, Nobuyuki Zettsu

Journal of Materials Chemistry A　12　(12)　7107-7121　2024/01/11

DOI： 10.1039/d3ta03494a 　

ISSN： 2050-7488

eISSN： 2050-7496
ARIM-mdx Data System: Towards a Nationwide Data Platform for Materials Science.

Masatoshi Hanai, Ryo Ishikawa, Mitsuaki Kawamura, Masato Ohnishi, Norio Takenaka, Kou Nakamura, Daiju Matsumura, Seiji Fujikawa, Hiroki Sakamoto, Yukinori Ochiai, Tetsuo Okane, Shin-Ichiro Kuroki, Atsuo Yamada, Toyotaro Suzumura, Junichiro Shiomi, Kenjiro Taura, Yoshio Mita, Naoya Shibata, Yuichi Ikuhara

CoRR　abs/2409.06734　2024

DOI： 10.48550/arXiv.2409.06734 　
Unusual Crystal Orientation in Hexagonal HoFeO<inf>3</inf> Multiferroic Films and the Effect on Magnetism

Binjie Chen, Jinghuang Lin, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta, Tsukasa Katayama

Crystal Growth and Design　2024

DOI： 10.1021/acs.cgd.4c00930 　

ISSN： 1528-7483

eISSN： 1528-7505
Highly Reversible Conversion-Type CoSn<inf>2</inf> Cathode for Fluoride-Ion Batteries

Shun Sasano, Ryo Ishikawa, Kazuaki Kawahara, Naoya Shibata, Yuichi Ikuhara

Small　2024

DOI： 10.1002/smll.202408023 　

ISSN： 1613-6810

eISSN： 1613-6829
Point-defect chemistry for ionic conduction in solid electrolytes with isovalent cation mixing

Takafumi Ogawa, Kazuyuki Sato, Kazuhiro Mori, Shunsuke Kobayashi, Hiroki Moriwake, Yuichi Ikuhara, Akihide Kuwabara

Journal of Materials Chemistry A　2024

DOI： 10.1039/d4ta05684a 　

ISSN： 2050-7488

eISSN： 2050-7496
Composite anode for fluoride-ion batteries using alloy formation and phase separation in charge and discharge processes

Kei Nakayama, Hidenori Miki, Takashi Nakagawa, Kousuke Noi, Yoshihiro Sugawara, Shunsuke Kobayashi, Katsutoshi Sakurai, Hideki Iba, Akihide Kuwabara, Yuichi Ikuhara, Takeshi Abe

Journal of Materials Chemistry A　12　(14)　8350-8358　2024
Publisher: Royal Society of Chemistry (RSC)
DOI： 10.1039/d3ta07038g 　

ISSN： 2050-7488

eISSN： 2050-7496
Ultrahigh-resolution Magnetic Field Imaging by Magnetic-field-free Atomic Resolution Electron Microscopy

Takehito SEKI, Yuji KOHONO, Yuichi IKUHARA, Naoya SHIBATA

Vacuum and Surface Science　66　(12)　683-688　2023/12/10
Publisher: Surface Science Society Japan
DOI： 10.1380/vss.66.683 　

ISSN： 2433-5835

eISSN： 2433-5843
Incommensurate grain-boundary atomic structure

Takehito Seki, Toshihiro Futazuka, Nobusato Morishige, Ryo Matsubara, Yuichi Ikuhara, Naoya Shibata

Nature Communications　14　(1)　2023/12

DOI： 10.1038/s41467-023-43536-0 　

eISSN： 2041-1723
La-Al Intermetallic Alloy Anode for Realizing High-Energy Fluoride-Ion Battery

Shun Sasano, Ryo Ishikawa, Kazuaki Kawahara, Naoya Shibata, Yuichi Ikuhara

Journal of The Electrochemical Society　170　(12)　2023/12/01

DOI： 10.1149/1945-7111/ad136e 　

ISSN： 0013-4651

eISSN： 1945-7111
High-mobility rutile SnO2 epitaxial films grown on (1−100) α-Al2O3

Binjie Chen, Jinghuang Lin, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta

Journal of the Ceramic Society of Japan　131　(10)　640-644　2023/10/01
Publisher: Ceramic Society of Japan
DOI： 10.2109/jcersj2.23035 　

ISSN： 1882-0743

eISSN： 1348-6535
The effect of annealing atmospheres on the segregation behaviors in Ti-doped α-Al2O3 grain boundary

Chuchu Yang, Bin Feng, Naoya Shibata, Yuichi Ikuhara

Journal of the Ceramic Society of Japan　131　(10)　608-612　2023/10/01
Publisher: Ceramic Society of Japan
DOI： 10.2109/jcersj2.23054 　

ISSN： 1882-0743

eISSN： 1348-6535
Effect of oxygen potential gradient on mass transfer along grain boundary in alumina bicrystal

Tsuneaki Matsudaira, Takafumi Ogawa, Miyuki Takeuchi, Jiake Wei, Bin Feng, Naoya Shibata, Yuichi Ikuhara, Satoshi Kitaoka

Journal of the Ceramic Society of Japan　131　(10)　632-639　2023/10/01
Publisher: Ceramic Society of Japan
DOI： 10.2109/jcersj2.23073 　

ISSN： 1882-0743

eISSN： 1348-6535
Effect of oxygen potential gradient on mass transfer along grain boundary in alumina bicrystal

Tsuneaki Matsudaira, Takafumi Ogawa, Miyuki Takeuchi, Jiake Wei, Bin Feng, Naoya Shibata, Yuichi Ikuhara, Satoshi Kitaoka

Journal of the Ceramic Society of Japan　131　(10)　632-639　2023/10/01
Publisher: Ceramic Society of Japan
DOI： 10.2109/jcersj2.23073 　

ISSN： 1882-0743

eISSN： 1348-6535
Direct observation of intrinsic core structure of a partial dislocation in ZnS

Bin Feng, Sena Hoshino, Bin Miao, Jiake Wei, Yu Ogura, Atsutomo Nakamura, Eita Tochigi, Katsuyuki Matsunaga, Yuichi Ikuhara, Naoya Shibata

Journal of the Ceramic Society of Japan　131　(10)　659-664　2023/10/01
Publisher: Ceramic Society of Japan
DOI： 10.2109/jcersj2.23065 　

ISSN： 1882-0743

eISSN： 1348-6535
Tetragonal phase stabilization and densification in AC flash-sintered 1.5 mol% yttria-stabilized zirconia polycrystals with high toughness Peer-reviewed

Fei Shen Ong, Kohta Nambu, Kohei Hosoi, Kenta Kawamura, Hiroshi Masuda, Bin Feng, Koji Matsui, Yuichi Ikuhara, Hidehiro Yoshida

Journal of the European Ceramic Society　44　(2)　1036-1043　2023/09

DOI： 10.1016/j.jeurceramsoc.2023.09.010 　

ISSN： 0955-2219

eISSN： 1873-619X
Shedding new light on the dislocation-mediated plasticity in wurtzite ZnO single crystals by photoindentation

Yan Li, Xufei Fang, Eita Tochigi, Yu Oshima, Sena Hoshino, Takazumi Tanaka, Hiroto Oguri, Shigenobu Ogata, Yuichi Ikuhara, Katsuyuki Matsunaga, Atsutomo Nakamura

Journal of Materials Science & Technology　156　206-216　2023/09
Publisher: Elsevier BV
DOI： 10.1016/j.jmst.2023.02.017 　

ISSN： 1005-0302
Direct imaging of local atomic structures in zeolite using optimum bright-field scanning transmission electron microscopy

Kousuke Ooe, Takehito Seki, Kaname Yoshida, Yuji Kohno, Yuichi Ikuhara, Naoya Shibata

Science Advances　9　(31)　2023/08/02
Publisher: American Association for the Advancement of Science (AAAS)
DOI： 10.1126/sciadv.adf6865 　

eISSN： 2375-2548
Real-time Tracking of Atomic Dynamics

Ryo Ishikawa, Yu Jimbo, Naoya Shibata, Yuichi Ikuhara

Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada　29　(1)　1372-1373　2023/07/22

DOI： 10.1093/micmic/ozad067.705 　

eISSN： 1435-8115
Sodium-ion migration in secondary battery cathode material Na4Co3(PO4)2P2O7: A first-principles molecular dynamics study

Hiroki Moriwake, Akihide Kuwabara, Craig A. J. Fisher, Keiichi Kohama, Masafumi Nose, Shinji Nakanishi, Hideki Iba, Yuichi Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　131　(7)　279-283　2023/07

DOI： 10.2109/jcersj2.22157 　

ISSN： 1882-0743

eISSN： 1348-6535
Ultrahigh toughness zirconia ceramics

Koji Matsui, Kohei Hosoi, Bin Feng, Hidehiro Yoshida, Yuichi Ikuhara

Proceedings of the National Academy of Sciences　120　(27)　2023/06/26
Publisher: Proceedings of the National Academy of Sciences
DOI： 10.1073/pnas.2304498120 　

ISSN： 0027-8424

eISSN： 1091-6490

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The attainment of both high strength and toughness is the ultimate goal for most structural materials. Although ceramic material has been considered for use as a structural material due to its high strength and good chemical stability, it suffers from the limitation of low toughness. For instance, although Y ₂ O ₃ -stabilized tetragonal ZrO ₂ polycrystals (Y-TZPs) exhibit remarkable toughness among ceramics due to their phase transformation toughening mechanism, this toughness is still much weaker than that of metals. Here, we report Y-TZP-based ceramic materials with toughnesses exceeding 20 MPa m ^1/2 , which is comparable to those of metals, while maintaining strengths over 1,200 MPa. The superior mechanical properties are realized by reducing the phase stability of tetragonal zirconia by tailoring the microstructure and chemistry of the Y-TZP. The proposed ceramic materials can further advance the design and application of ceramic-based structural materials.
Effect of oxygen potential gradient on mass transfer in polycrystalline alumina film doped with trace elements

Tsuneaki Matsudaira, Takafumi Ogawa, Miyuki Takeuchi, Naoya Shibata, Yuichi Ikuhara, Satoshi Kitaoka

Acta Materialia　252　118927-118927　2023/06
Publisher: Elsevier BV
DOI： 10.1016/j.actamat.2023.118927 　

ISSN： 1359-6454
Atomic and electronic structure of grain boundaries in a-Al<inf>2</inf>O<inf>3</inf>: A combination of machine learning, first-principles calculation and electron microscopy

T. Yokoi, A. Hamajima, J. Wei, B. Feng, Y. Oshima, K. Matsunaga, N. Shibata, Y. Ikuhara

Scripta Materialia　229　2023/05

DOI： 10.1016/j.scriptamat.2023.115368 　

ISSN： 1359-6462
Suppression of Strain Relaxation in VO₂/TiO₂ Multilayered Films

Binjie Chen, Chuchu Yang, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta

ACS Applied Electronic Materials　5　(4)　2433-2438　2023/04/04
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acsaelm.3c00246 　

ISSN： 2637-6113

eISSN： 2637-6113
Ion diffusion across/along symmetric tilt grain boundaries in yttria-stabilized zirconia investigated by molecular dynamics simulations

Susumu Ikeda, Bin Feng, Naoya Shibata, Yuichi Ikuhara

Solid State Ionics　392　116163-116163　2023/04
Publisher: Elsevier BV
DOI： 10.1016/j.ssi.2023.116163 　

ISSN： 0167-2738
Real-space observation of a two-dimensional electron gas at semiconductor heterointerfaces

Satoko Toyama, Takehito Seki, Yuya Kanitani, Yoshihiro Kudo, Shigetaka Tomiya, Yuichi Ikuhara, Naoya Shibata

Nature Nanotechnology　18　(5)　521-528　2023/03/20
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s41565-023-01349-8 　

ISSN： 1748-3387

eISSN： 1748-3395
Mathematical Description for the Hierarchy of Grain-boundary Structures

Kazutoshi INOUE, Motoko KOTANI, Yuichi IKUHARA

Vacuum and Surface Science　66　(3)　146-151　2023/03/10
Publisher: Surface Science Society Japan
DOI： 10.1380/vss.66.146 　

ISSN： 2433-5835 2433-5843

eISSN： 2433-5843

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Polycrystalline materials are ubiquitous, and their macroscopic properties strongly depend on the defects in crystalline structures. Grain boundaries (GBs) are the interfaces between crystal grains, which admit unique atomic arrangements different from those of crystals. It is essential to reveal the polyhedral arrangement in GB atomic structures to identify the origin of structure-property relationships in polycrystalline materials. We found that the GB region can only be packed by the bulk or GB-type polyhedral units with minor variations. Moreover, the GB hierarchy directly follows the distribution of rational numbers that is represented by the Farey diagram. The singular GB is defined to be a GB packed by at the most two types of polyhedral units in a period, and any GB can be packed by the polyhedral units that form the singular GBs. This approach allows us to predict the polyhedral arrangement in any tilt GBs including random GBs.
Solid‐State Electrochemical Thermal Transistors

Qian Yang, Hai Jun Cho, Zhiping Bian, Mitsuki Yoshimura, Joonhyuk Lee, Hyoungjeen Jeen, Jinghuang Lin, Jiake Wei, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta

Advanced Functional Materials　33　(19)　2214939-2214939　2023/02/21
Publisher: Wiley
DOI： 10.1002/adfm.202214939 　

ISSN： 1616-301X

eISSN： 1616-3028
Fluoride Ion Conductivity of Rb Doped KSbF4

Kazuaki Kawahara, Ryo Ishikawa, Naoya Shibata, Yuichi Ikuhara

Journal of The Electrochemical Society　170　(2)　2023/02/16
Publisher: The Electrochemical Society
DOI： 10.1149/1945-7111/acbca5 　

ISSN： 0013-4651

eISSN： 1945-7111
深さ断層法による3次元電子顕微鏡法 Invited Peer-reviewed

石川亮, 柴田直哉, 幾原雄一

92　(2)　74-78　2023/02

DOI： 10.11470/oubutsu.92.2_74 　
Formation of La-rich tysonite nano-precipitates in fluorite Ba0.6La0.4F2.4

Shun Sasano, Ryo Ishikawa, Kazuaki Kawahara, Atsushi Mineshige, Naoya Shibata, Yuichi Ikuhara

Journal of Power Sources　557　232581-232581　2023/02
Publisher: Elsevier BV
DOI： 10.1016/j.jpowsour.2022.232581 　

ISSN： 0378-7753
Atomistic grain boundary migration in Al₂O₃

Bin Feng, Jiake Wei, Naoya Shibata, Yuichi Ikuhara

International Journal of Ceramic Engineering & Science　5　(1)　2023/01/11
Publisher: Wiley
DOI： 10.1002/ces2.10169 　

ISSN： 2578-3270

eISSN： 2578-3270
Defect structures and dopant solution states of Hf-doped Si<inf>3</inf>N<inf>4</inf> ceramics

Akihide Kuwabara, Xiang Gao, Ralf Riedel, Emanuel Ionescu, Yuichi Ikuhara

International Journal of Applied Ceramic Technology　20　(1)　190-196　2023

DOI： 10.1111/ijac.14236 　

ISSN： 1546-542X

eISSN： 1744-7402
Highly luminescent and narrow-band-emitting InP/ZnSe/ZnS quantum dot synthesis by halide modified shell reaction

Takafumi Moriyama, Akihito Kumamoto, Makoto Kido, Hirokazu Sasaki, Thomas Novet, Naoya Shibata, Yuichi Ikuhara

Applied Physics Express　16　(1)　2023/01

DOI： 10.35848/1882-0786/aca9ba 　

ISSN： 1882-0778

eISSN： 1882-0786
CeO₂ supported high-valence Fe oxide for highly active and stable water oxidation

Hongzhi Liu, Jun Yu, Jinghuang Lin, Bin Feng, Mingzi Sun, Chen Qiu, Kun Qian, Zhichun Si, Bolong Huang, Jean-Jacques Delaunay, Yuichi Ikuhara, Shihe Yang

EES Catalysis　1　(5)　720-729　2023
Publisher: Royal Society of Chemistry (RSC)
DOI： 10.1039/d3ey00113j 　

eISSN： 2753-801X
Single‐atom microscopy in wide‐bandgap nitrides

Ryo Ishikawa, Naoya Shibata, Fumiyasu Oba, Takashi Taniguchi, Yuichi Ikuhara

International Journal of Applied Ceramic Technology　20　(1)　166-173　2023/01

DOI： 10.1111/ijac.14134 　

ISSN： 1546-542X

eISSN： 1744-7402
Grain boundary structural transformation induced by co-segregation of aliovalent dopants

Toshihiro Futazuka, Ryo Ishikawa, Naoya Shibata, Yuichi Ikuhara

Nature Communications　13　(1)　2022/12

DOI： 10.1038/s41467-022-32935-4 　

eISSN： 2041-1723
Formation Mechanisms of Rhombohedral Twinning in Sapphire

Eita Tochigi, Bin Miao, Atsutomo Nakamura, Naoya Shibata, Yuichi Ikuhara

Materia Japan　61　(12)　856-859　2022/12/01
Publisher: Japan Institute of Metals
DOI： 10.2320/materia.61.856 　

ISSN： 1340-2625

eISSN： 1884-5843
Orthorhombic distortion-induced anatase-like optoelectronic properties of rutile TiO₂

Binjie Chen, Kungwan Kang, Hyoungjeen Jeen, Yuqiao Zhang, Jinghuang Lin, Bin Feng, Yuichi Ikuhara, Sena Hoshino, Katsuyuki Matsunaga, Hiromichi Ohta

Journal of Applied Physics　132　(18)　185301-185301　2022/11/14
Publisher: AIP Publishing
DOI： 10.1063/5.0119725 　

ISSN： 0021-8979

eISSN： 1089-7550
Highly Durable Bifunctional Gas Diffusion Electrodes Fabricated with Melilite-Type Fe/Co/Ni-Mixed Oxide Electrocatalysts

Satoshi Ogawa, Kei Nakayama, Misaki Katayama, Ryo Ishikawa, Yuichi Ikuhara, Miwa Saito, Teruki Motohashi

ACS Applied Energy Materials　5　(12)　15502-15509　2022/11/09
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acsaem.2c03084 　

ISSN： 2574-0962

eISSN： 2574-0962
Fabricating one-dimensional van der Waals heterostructures on chirality-sorted single-walled carbon nanotubes

Ruixi Zhang, Ya Feng, Henan Li, Akihito Kumamoto, Shuhui Wang, Yongjia Zheng, Wanyu Dai, Nan Fang, Ming Liu, Takeshi Tanaka, Yuichiro K. Kato, Hiromichi Kataura, Yuichi Ikuhara, Shigeo Maruyama, Rong Xiang

Carbon　199　407-414　2022/10
Publisher: Elsevier BV
DOI： 10.1016/j.carbon.2022.07.076 　

ISSN： 0008-6223
Crystal Defect Core Studied by Advanced Electron Microscopy

Bin Feng, Jiake Wei, Ryo Ishikawa, Takehito Seki, Naoya Shibata, Yuichi Ikuhara

Materia Japan　61　(10)　640-644　2022/10/01
Publisher: Japan Institute of Metals
DOI： 10.2320/materia.61.640 　

ISSN： 1340-2625

eISSN： 1884-5843
Linear imaging theory for differential phase contrast and other phase imaging modes in scanning transmission electron microscopy

Takehito Seki, Kushagra Khare, Yoshiki O. Murakami, Satoko Toyama, Gabriel Sánchez-Santolino, Hirokazu Sasaki, Scott D. Findlay, Timothy C. Petersen, Yuichi Ikuhara, Naoya Shibata

Ultramicroscopy　240　113580-113580　2022/10
Publisher: Elsevier BV
DOI： 10.1016/j.ultramic.2022.113580 　

ISSN： 0304-3991
Spatial and phase resolution in electron microscopy

Ryo Ishikawa, Shigeyuki Morishita, Toshiaki Tanigaki, Naoya Shibata, Yuichi Ikuhara

Microscopy　72　(2)　78-96　2022/09/12
Publisher: Oxford University Press (OUP)
DOI： 10.1093/jmicro/dfac045 　

ISSN： 2050-5698

eISSN： 2050-5701
Enhanced high-temperature volume resistivity of AlN by doping

Daiki Kato, Bin Feng, Yasunobu Noritake, Tomoko Hishida, Naoya Shibata, Yuichi Ikuhara

Applied Physics Express　15　(9)　095501-095501　2022/08/10
Publisher: IOP Publishing
DOI： 10.35848/1882-0786/ac851f 　

ISSN： 1882-0778

eISSN： 1882-0786

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Abstract The addition of various oxide dopants for AlN were investigated aiming to increase the AlN volume resistivity at high temperature. It was confirmed that the volume resistivity of 1 mol% MgO doped AlN shows four orders of magnitude higher than that of non-doped AlN. To further clarify the effect of MgO doping, we sintered various kinds of AlN with different MgO concentration and grain sizes, and the microstructures were investigated by transmission electron microscopy. The results suggest the inversion domain boundary appeared in the MgO doped AlN might be the possible reason for the increase of volume resistivity.
Quantitative electric field mapping in semiconductor heterostructures via tilt-scan averaged DPC STEM

Satoko Toyama, Takehito Seki, Yuya Kanitani, Yoshihiro Kudo, Shigetaka Tomiya, Yuichi Ikuhara, Naoya Shibata

Ultramicroscopy　238　113538-113538　2022/08
Publisher: Elsevier BV
DOI： 10.1016/j.ultramic.2022.113538 　

ISSN： 0304-3991
Atomic-resolution STEM image denoising by total variation regularization Peer-reviewed

Kazuaki Kawahara, Ryo Ishikawa, Shun Sasano, Naoya Shibata, Yuichi Ikuhara

Microscopy　71　(5)　302-310　2022/06/17
Publisher: Oxford University Press (OUP)
DOI： 10.1093/jmicro/dfac032 　

ISSN： 2050-5698

eISSN： 2050-5701

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Abstract Atomic-resolution electron microscopy imaging of solid-state material is a powerful method for structural analysis. Scanning transmission electron microscopy (STEM) is one of the actively used techniques to directly observe atoms in materials. However, some materials are easily damaged by the electron beam irradiation, and only noisy images are available when we decrease the electron dose to avoid beam damages. Therefore, a denoising process is necessary for precise structural analysis in low-dose STEM. In this study, we propose total variation (TV) denoising algorithm to remove quantum noise in an STEM image. We defined an entropy of STEM image that corresponds to the image contrast to determine a hyperparameter and we found that there is a hyperparameter that maximizes the entropy. We acquired atomic-resolution STEM image of CaF2 viewed along the [001] direction and executed TV denoising. The atomic columns of Ca and F are clearly visualized by the TV denoising, and atomic positions of Ca and F are determined with the error of ±1 pm and ±4 pm, respectively.
Lithium Lanthanum Titanate Single Crystals: Dependence of Lithium-Ion Conductivity on Crystal Domain Orientation

Shunsuke Kobayashi, Daisaku Yokoe, Yasuyuki Fujiwara, Kazuaki Kawahara, Yuichi Ikuhara, Akihide Kuwabara

Nano Letters　2022/06/13
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.nanolett.2c01655 　

ISSN： 1530-6984

eISSN： 1530-6992
Reliable electrochemical setup for in situ observations with an atmospheric SEM Peer-reviewed

Yoshida, K., Sasaki, Y., Kuwabara, A., Ikuhara, Y.

Microscopy　71　(5)　2022/06/11

DOI： 10.1093/jmicro/dfac028 　

ISSN： 2050-5701 2050-5698
Direct Observation of Atomistic Reaction Process between Pt Nanoparticles and TiO2 (110) Peer-reviewed

Ryo Ishikawa, Yujiro Ueno, Yuichi Ikuhara, Naoya Shibata

Nano Letters　22　(10)　4161-4167　2022/05/25
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acs.nanolett.2c00929 　

ISSN： 1530-6984

eISSN： 1530-6992
Design and fabrication of an electrochemical chip for liquid-phase transmission electron microscopy

Yuki Sasaki, Ayako Mizushima, Yoshio Mita, Kaname Yoshida, Akihide Kuwabara, Yuichi Ikuhara

Microscopy　2022/05/04
Publisher: Oxford University Press (OUP)
DOI： 10.1093/jmicro/dfac023 　

ISSN： 2050-5698

eISSN： 2050-5701

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Abstract Liquid-phase transmission electron microscopy (LP-TEM) can be used with an electrochemical chip (e-chip) to observe electrochemical reactions in a liquid in situ. The design of electrodes on an e-chip fabricated using microelectromechanical system technology cannot be easily changed. Here, we report a newly designed e-chip and its fabrication process. Electrodes with a desired shape were fabricated with various metals via an additional step of vacuum deposition onto our e-chip with a shadow mask. For precise control of the electrochemical reactions in LP-TEM, optimization of the electrode shape and material is critical.
Atomic and electronic band structures of Y-doped Al2O3 grain boundaries

Chuchu Yang, Bin Feng, Jiake Wei, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　130　(3)　286-289　2022/03

DOI： 10.2109/jcersj2.21168 　

ISSN： 1882-0743

eISSN： 1348-6535
Direct imaging of the disconnection climb mediated point defects absorption by a grain boundary

Jiake Wei, Bin Feng, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara

NATURE COMMUNICATIONS　13　(1)　2022/03

DOI： 10.1038/s41467-022-29162-2 　

eISSN： 2041-1723
The Observation of Local Electric Fields in GaN/AlGaN/InGaN Multi-heterostructures by Differential Phase Contrast STEM

Satoko Toyama, Takehito Seki, Yuya Kanitani, Shigetaka Tomiya, Yuichi Ikuhara, Naoya Shibata

IEEJ Transactions on Electronics, Information and Systems　142　(3)　367-372　2022/03/01
Publisher: Institute of Electrical Engineers of Japan (IEE Japan)
DOI： 10.1541/ieejeiss.142.367 　

ISSN： 0385-4221

eISSN： 1348-8155
Factors limiting quantitative phase retrieval in atomic-resolution differential phase contrast scanning transmission electron microscopy using a segmented detector

T. Mawson, D.J. Taplin, H.G. Brown, L. Clark, R. Ishikawa, T. Seki, Y. Ikuhara, N. Shibata, D.M. Paganin, M.J. Morgan, M. Weyland, T.C. Petersen, S.D. Findlay

Ultramicroscopy　233　113457-113457　2022/03
Publisher: Elsevier BV
DOI： 10.1016/j.ultramic.2021.113457 　

ISSN： 0304-3991
Effect of annealing on grain growth and Y segregation behavior in tetragonal ZrO 2 thin film

Hiroaki Nakade, Eita Tochigi, Bin Feng, Ryo Ishikawa, Hiromichi Ohta, Naoya Shibata, Yuichi Ikuhara

Journal of the American Ceramic Society　105　(3)　2300-2308　2022/03
Publisher: Wiley
DOI： 10.1111/jace.18217 　

ISSN： 0002-7820

eISSN： 1551-2916
Real-space visualization of intrinsic magnetic fields of an antiferromagnet

Yuji Kohno, Takehito Seki, Scott D. Findlay, Yuichi Ikuhara, Naoya Shibata

Nature　602　(7896)　234-239　2022/02/10
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s41586-021-04254-z 　

ISSN： 0028-0836

eISSN： 1476-4687
Atomic-Level Changes during Electrochemical Cycling of Oriented LiMn₂O₄ Cathodic Thin Films

Yumi H. Ikuhara, Xiang Gao, Kazuaki Kawahara, Craig A. J. Fisher, Akihide Kuwabara, Ryo Ishikawa, Hiroki Moriwake, Yuichi Ikuhara

ACS Applied Materials & Interfaces　14　(5)　6507-6517　2022/02/09
Publisher: American Chemical Society (ACS)
DOI： 10.1021/acsami.1c18630 　

ISSN： 1944-8244

eISSN： 1944-8252
Low-temperature degradation in yttria-stabilized tetragonal zirconia polycrystal: Effect of Y³⁺ distribution in grain interiors

Matsui, K., Nakamura, K., Saito, M., Kuwabara, A., Yoshida, H., Ikuhara, Y.

Acta Materialia　227　2022

DOI： 10.1016/j.actamat.2022.117659 　

ISSN： 1359-6454
TEM Characterization of Lattice Defects Associated with Deformation and Fracture in α-Al₂O₃

Tochigi, E., Miao, B., Kondo, S., Shibata, N., Ikuhara, Y.

The Plaston Concept: Plastic Deformation in Structural Materials　2022

DOI： 10.1007/978-981-16-7715-1_7 　
70th anniversary issue: Preface

Ikuhara, Y.

Microscopy　71　2022

DOI： 10.1093/jmicro/dfac001 　

ISSN： 2050-5701 2050-5698
Fluoride-ion conversion alloy for fluoride-ion batteries Peer-reviewed

Nakayama, K., Ishikawa, R., Tojigamori, T., Miki, H., Iba, H., Shibata, N., Ikuhara, Y.

Journal of Materials Chemistry A　10　(7)　2022
Publisher: Royal Society of Chemistry ({RSC})
DOI： 10.1039/d1ta09324j 　

ISSN： 2050-7496 2050-7488
Oxygen atom ordering on SiO<inf>2</inf>/4H-SiC {0001} polar interfaces formed by wet oxidation

Mitsuhiro Saito, Hongping Li, Kazutoshi Inoue, Hirofumi Matsuhata, Yuichi Ikuhara

Acta Materialia　221　2021/12

DOI： 10.1016/j.actamat.2021.117360 　

ISSN： 1359-6454
Breaking of Thermopower-Conductivity Trade-Off in LaTiO3 Film around Mott Insulator to Metal Transition

Takayoshi Katase, Xinyi He, Terumasa Tadano, Jan M. Tomczak, Takaki Onozato, Keisuke Ide, Bin Feng, Tetsuya Tohei, Hidenori Hiramatsu, Hiromichi Ohta, Yuichi Ikuhara, Hideo Hosono, Toshio Kamiya

ADVANCED SCIENCE　8　(23)　2021/12

DOI： 10.1002/advs.202102097 　

eISSN： 2198-3844
Solid-State Electrochemical Switch of Superconductor-Metal-Insulators

Xi Zhang, Gowoon Kim, Qian Yang, Jiake Wei, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta

ACS Applied Materials and Interfaces　13　(45)　54204-54209　2021/11/17
Publisher: American Chemical Society
DOI： 10.1021/acsami.1c17014 　

ISSN： 1944-8252 1944-8244
Unveiling the electronic structure of grain boundaries in anatase with electron microscopy and first-principles modeling

James A. Quirk, Bin Miao, Bin Feng, Gowoon Kim, Hiromichi Ohta, Yuichi Ikuhara, Keith P. McKenna

Nano Letters　21　(21)　9217-9223　2021/11/10
Publisher: American Chemical Society
DOI： 10.1021/acs.nanolett.1c03099 　

ISSN： 1530-6992 1530-6984
On-Chip Electrochemical Analysis Combined with Liquid-Phase Electron Microscopy of Zinc Deposition/Dissolution

Yuki Sasaki, Kaname Yoshida, Akihide Kuwabara, Yuichi Ikuhara

Journal of The Electrochemical Society　168　(11)　112511-112511　2021/11/01
Publisher: The Electrochemical Society
DOI： 10.1149/1945-7111/ac39e0 　

ISSN： 0013-4651

eISSN： 1945-7111

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Dendrite growth of Zn on the anode of Zn-based rechargeable batteries can cause short-circuiting. To avoid the formation of dendrites, the Zn deposition/dissolution behaviors and their dependence on the electrochemical conditions should be clarified. In this study, <italic>in situ</italic> transmission electron microscopy (TEM) observations using an electrochemical chip (e-chip) were conducted to visualize the initial stage of the electrodeposition of Zn on an anode. The electrochemical data corresponding to the <italic>in situ</italic> TEM observations were precisely and extensively analyzed. The combined optimized use of a potentiostat and transmission electron microscope enabled electrochemical electrodes to be isolated completely from the potential of the TEM column. This environment stabilized the electrodeposition process during the <italic>in situ</italic> TEM observations. Under constant-current mode, the electric potential was varied, resulting in the deposition of various amounts of Zn onto the Pt working electrode. Controlling the surface materials of the electrodes and the electrochemical conditions was important for <italic>in situ</italic> TEM observations of electrochemical reactions.
Surface segregation of 3mol% yttria-doped tetragonal zirconia particle studied by atomic-resolution scanning transmission electron microscopy-energy-dispersive X-ray spectroscopy

Bin Feng, Akihito Kumamoto, Koji Matsui, Masatoshi Tanemura, Masato Yoshiya, Hidehiro Yoshida, Yuichi Ikuhara

Journal of the Ceramic Society of Japan　129　(9)　561-565　2021/09/01

DOI： 10.2109/jcersj2.21032 　

ISSN： 1882-0743

eISSN： 1348-6535
Fabrication of calcite-core/Mg-calcite-shell nanorods for better thermal stability

Yuki Kezuka, Eita Tochigi, Hidenobu Murata, Maya Yoshida, Atsushi Nakahira, Yuichi Ikuhara, Masahiko Tajika

Advanced Powder Technology　2021/06
Publisher: Elsevier BV
DOI： 10.1016/j.apt.2021.05.033 　

ISSN： 0921-8831
Spin Polarization-Assisted Dopant Segregation at a Coherent Phase Boundary

Jiang, Y., Li, H., Yao, T., Wang, Y., Yin, D., Chen, C., Ma, X., Ye, H., Ikuhara, Y.

ACS Nano　15　(12)　2021

DOI： 10.1021/acsnano.1c07449 　

ISSN： 1936-086X 1936-0851
Surfactant-mediated morphology evolution and self-assembly of cerium oxide nanocrystals for catalytic and supercapacitor applications

Xiaodong Hao, Shuai Zhang, Yang Xu, Liangyu Tang, Kazutoshi Inoue, Mitsuhiro Saito, Shufang Ma, Chunlin Chen, Bingshe Xu, Tadafumi Adschiri, Yuichi Ikuhara

Nanoscale　13　(23)　10393-10401　2021
Publisher: Royal Society of Chemistry (RSC)
DOI： 10.1039/d1nr01746b 　

ISSN： 2040-3364

eISSN： 2040-3372

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Surfactant-mediated morphology evolution of CeO₂ nanocrystals is fully investigated at the atomic scale and it was found that the exposure of {100} facets largely affects the concentration of Ce³⁺ and subsequently the OSC performance.
High Electron and Low Heat Transports of 1D Atomic Defect Tunnels Stabilized in Tungsten Oxide Epitaxial Films

Gowoon Kim, Bin Feng, Yu-Miin Sheu, Hai Jun Cho, Yuichi Ikuhara, Hiromichi Ohta

ECS Meeting Abstracts　2020/11/23

DOI： 10.1149/MA2020-02291970mtgabs 　
Fabrication and Characterization of Ba1/3CoO2Epitaxial Films Exhibiting Thermoelectric ZT = 0.12 at Room Temperature

Yugo Takashima, Yu-Qiao Zhang, Jiake Wei, Bin Feng, Yuichi Ikuhara, Hai Jun Cho, Hiromichi Ohta

Proceedings of AM-FPD 2020 - 27th International Workshop on Active-Matrix Flatpanel Displays and Devices: TFT Technologies and FPD Materials　123-126　2020/09/01
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.23919/AM-FPD49417.2020.9224485 　
Composition gradient (1-x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 film with improved dielectric, piezoelectric and ferroelectric temperature stability

Ruijian Zhu, Zengmei Wang, Zhenxiang Cheng, Xinli Guo, Tong Zhang, Zhonglan Cai, Hideo Kimura, Takao Matsumoto, Naoya Shibata, Yuichi Ikuhara

Ceramics International　46　(12)　20284-20290　2020/08/15
Publisher: Elsevier Ltd
DOI： 10.1016/j.ceramint.2020.05.111 　

ISSN： 0272-8842
Quantitative electric field mapping of a p–n junction by DPC STEM Peer-reviewed

Toyama, S., Seki, T., Anada, S., Sasaki, H., Yamamoto, K., Ikuhara, Y., Shibata, N.

Ultramicroscopy　216　2020/06

DOI： 10.1016/j.ultramic.2020.113033 　

ISSN： 1879-2723 0304-3991
Thickness-dependent frictional behavior of topological insulator Bi2Se3 nanoplates

Ruijian Zhu, Zengmei Wang, Quanzhou Yao, Qunyang Li, Zhenxiang Cheng, Xinli Guo, Tong Zhang, Xiaoshuai Li, Hideo Kimura, Takao Matsumoto, Naoya Shibata, Yuichi Ikuhara

Applied Physics A: Materials Science and Processing　126　(4)　2020/04/01
Publisher: Springer
DOI： 10.1007/s00339-020-3452-5 　

ISSN： 1432-0630 0947-8396
Grain boundary functions as a spin valve

Ikuhara, Y.

National Science Review　7　(7)　2020

DOI： 10.1093/NSR/NWAA074 　

ISSN： 2053-714X 2095-5138
TV-rate Atomic-resolution STEM Imaging

Ryo Ishikawa, Yu Jimbo, Mitsuhisa Terao, Masashi Nishikawa, Yujiro Ueno, Shigeyuki Morishita, Masaki Mukai, Naoya Shibata, Yuichi Ikuhara

Microscopy and Microanalysis　2020
Publisher: Cambridge University Press
DOI： 10.1017/S1431927620017122 　

ISSN： 1435-8115 1431-9276
Ferroelectric Oxide Thin Film with an Out-of-Plane Electrical Conductivity Peer-reviewed

Yao, T., Jiang, Y., Chen, C., Yan, X., Tao, A., Yang, L., Li, C., Sugo, K., Ohta, H., Ye, H., Ikuhara, Y., Ma, X.

Nano Letters　20　(2)　2020

DOI： 10.1021/acs.nanolett.9b04210 　

ISSN： 1530-6992 1530-6984
Microscopic characterization of the C–F bonds in fluorine–graphite intercalation compounds Peer-reviewed

Yoshida, K., Sugawara, Y., Saitoh, M., Matsumoto, K., Hagiwara, R., Matsuo, Y., Kuwabara, A., Ukyo, Y., Ikuhara, Y.

Journal of Power Sources　445　227320　2020/01

DOI： 10.1016/j.jpowsour.2019.227320 　

ISSN： 0378-7753
Electrical polarization induced by atomically engineered compositional gradient in complex oxide solid solution

Ping-Chun Wu, Rong Huang, Ying-Hui Hsieh, Bo Wang, Min Yen, Sheng-Zhu Ho, Akihito Kumamoto, Chaorong Zhong, Haili Song, Yi-Chun Chen, Long-Qing Chen, Chun-Gang Duan, Yuichi Ikuhara, Ying-Hao Chu

NPG Asia Materials　11　(1)　2019/12/01
Publisher: Nature Publishing Group
DOI： 10.1038/s41427-019-0117-y 　

ISSN： 1884-4057 1884-4049
PM-03 New Magnetic Structure Imaging Techniques in Polycrystalline Materials by DPC STEM

Yoshiki O Murakami, Takehito Seki, Akihito Kinoshita, Tetsuya Shoji, Yuichi Ikuhara, Naoya Shibata

Microscopy　68　(Supplement_1)　i36-i36　2019/11/01
Publisher: Oxford University Press (OUP)
DOI： 10.1093/jmicro/dfz093 　

ISSN： 2050-5698

eISSN： 2050-5701
Carrier Depletion near the Grain Boundary of a SiC Bicrystal Peer-reviewed

Kim, Y.-W., Tochigi, E., Tatami, J., Kim, Y.-H., Jang, S.H., Javvaji, S., Jung, J., Kim, K.J., Ikuhara, Y.

Scientific Reports　9　(1)　2019/11
Publisher: Springer Science and Business Media {LLC}
DOI： 10.1038/s41598-019-54525-z 　

ISSN： 2045-2322
Strong metal–metal interaction and bonding nature in metal/oxide interfaces with large mismatches Peer-reviewed

Li, H., Saito, M., Chen, C., Inoue, K., Akagi, K., Ikuhara, Y.

Acta Materialia　179　237-246　2019/10/15

DOI： 10.1016/j.actamat.2019.08.018 　

ISSN： 1359-6454
Direct observation of electric field in GaN semiconductor hetero interface by DPC STEM

Toyama Satoko, Seki Takehito, Kanitani Yuya, Kudo Yoshihiro, Tomiya Shigetaka, Ikuhara Yuichi, Shibata Naoya

JSAP Annual Meetings Extended Abstracts　2019.2　1737-1737　2019/09/04
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/jsapmeeting.2019.2.0_1737 　

eISSN： 2436-7613
Synthesis of Tunable-Aspect-Ratio Calcite Nanoparticles via Mg²⁺ Doping Peer-reviewed

Kezuka, Y., Tochigi, E., Murata, H., Yoshida, M., Eguchi, K., Nakahira, A., Ikuhara, Y., Tajika, M.

Crystal Growth and Design　19　(11)　6784　2019/09
Publisher: American Chemical Society ({ACS})
DOI： 10.1021/acs.cgd.9b01196 　

ISSN： 1528-7505 1528-7483
Transition-Metal Distribution in Brownmillerite Ca₂FeCoO₅ Peer-reviewed

Nakayama, K., Ishikawa, R., Kuwabara, A., Kobayashi, S., Motohashi, T., Shibata, N., Ikuhara, Y.

Inorganic Chemistry　58　(15)　10209-10216　2019/08/05

DOI： 10.1021/acs.inorgchem.9b01356 　

ISSN： 1520-510X 0020-1669
Liquid-Crystalline Hydroxyapatite/Polymer Nanorod Hybrids: Potential Bioplatform for Photodynamic Therapy and Cellular Scaffolds Peer-reviewed

Nakayama, M., Lim, W.Q., Kajiyama, S., Kumamoto, A., Ikuhara, Y., Kato, T., Zhao, Y.

ACS Applied Materials and Interfaces　11　(19)　17759-17765　2019/07

DOI： 10.1021/acsami.9b02485 　

ISSN： 1944-8252 1944-8244
Atomic-scale structural identification and evolution of Co-W-C ternary SWCNT catalytic nanoparticles: High-resolution STEM imaging on SiO₂ Peer-reviewed

An, H., Kumamoto, A., Xiang, R., Inoue, T., Otsuka, K., Chiashi, S., Bichara, C., Loiseau, A., Li, Y., Ikuhara, Y., Maruyama, S.

Science Advances　5　(5)　eaat9459　2019/05

DOI： 10.1126/sciadv.aat9459 　

ISSN： 2375-2548
Determination of the structure and properties of an edge dislocation in rutile TiO₂ Peer-reviewed

Maras, E., Saito, M., Inoue, K., J{\'o}nsson, H., Ikuhara, Y., McKenna, K., P

Acta Materialia　163　199-207　2019/01/15

DOI： 10.1016/j.actamat.2018.10.015 　

ISSN： 1359-6454
Insights into fundamental deformation processes from advanced in situ transmission electron microscopy

Spiecker, E., Oh, S.H., Shan, Z.-W., Ikuhara, Y., Mao, S.

MRS Bulletin　44　(6)　2019

DOI： 10.1557/mrs.2019.129 　

ISSN： 0883-7694
Ceramic phases with one-dimensional long-range order Peer-reviewed

Yin, D., Chen, C., Saito, M., Inoue, K., Ikuhara, Y.

Nature Materials　18　(1)　19-+　2019/01

DOI： 10.1038/s41563-018-0240-0 　

ISSN： 1476-4660 1476-1122
Oxygen loss and surface degradation during electrochemical cycling of lithium-ion battery cathode material LiMn₂O₄ Peer-reviewed

Gao, X., Ikuhara, Y.H., Fisher, C.A.J., Huang, R., Kuwabara, A., Moriwake, H., Kohama, K., Ikuhara, Y.

Journal of Materials Chemistry A　7　(15)　8845-8854　2019/01

DOI： 10.1039/c8ta08083f 　

ISSN： 2050-7496 2050-7488
Stimuli-responsive hydroxyapatite liquid crystal with macroscopically controllable ordering and magneto-optical functions Peer-reviewed

Masanari Nakayama, Satoshi Kajiyama, Akihito Kumamoto, Tatsuya Nishimura, Yuichi Ikuhara, Masafumi Yamato, Takashi Kato

Nature Communications　9　(1)　2018/12/01

DOI： 10.1038/s41467-018-02932-7 　

ISSN： 2041-1723
Atomic-Scale Valence State Distribution inside Ultrafine CeO₂ Nanocubes and Its Size Dependence Peer-reviewed

Hao, X., Yoko, A., Chen, C., Inoue, K., Saito, M., Seong, G., Takami, S., Adschiri, T., Ikuhara, Y.

Small　14　(42)　2018/10/18

DOI： 10.1002/smll.201802915 　

ISSN： 1613-6829 1613-6810
Local chemical ordering within the incubation period as a trigger for nanocrystallization of a highly supercooled Ti-based liquid Peer-reviewed

Wang, Z., Chen, C., Ketov, S.V., Akagi, K., Tsarkov, A.A., Ikuhara, Y., Louzguine-Luzgin, D.V.

Materials and Design　156　504-513　2018/10/15

DOI： 10.1016/j.matdes.2018.07.013 　

ISSN： 1873-4197 0264-1275
Systematic analysis of electron energy-loss near-edge structures in Li-ion battery materials Peer-reviewed

Saitoh, M., Gao, X., Ogawa, T., Ikuhara, Y.H., Kobayashi, S., Fisher, C.A.J., Kuwabara, A., Ikuhara, Y.

Physical Chemistry Chemical Physics　20　(38)　25052-25061　2018/10

DOI： 10.1039/c8cp03390k 　

ISSN： 1463-9076
Lattice expansion and local lattice distortion in Nb- and La-doped SrTi O₃ single crystals investigated by x-ray diffraction and first-principles calculations Peer-reviewed

Kobayashi, S., Ikuhara, Y., Mizoguchi, T.

Physical Review B　98　(13)　134114　2018/10

DOI： 10.1103/PhysRevB.98.134114 　

ISSN： 2469-9969 2469-9950
Revealing tetragonal-to-monoclinic phase transformation in Y-TZP at an initial stage of low temperature degradation using grazing incident-angle X-ray diffraction measurement Peer-reviewed

Koyama, T., Kumamoto, A., Matsui, K., Ikuhara, Y., Yoshida, H.

Journal of the Ceramic Society of Japan　126　(9)　728-731　2018/09

DOI： 10.2109/jcersj2.18068 　

ISSN： 1348-6535 1882-0743
Crystallographic orientation-surface energy-wetting property relationships of rare earth oxides Peer-reviewed

Tam, J., Feng, B., Ikuhara, Y., Ohta, H., Erb, U.

Journal of Materials Chemistry A　6　(38)　2018/09

DOI： 10.1039/c8ta04938f 　

ISSN： 2050-7496 2050-7488
Structural changes and their effect on Li-ion conductivity upon quenching of La_(1-x)/3Li_xNbO₃ solid electrolytes Peer-reviewed

Hu, X., Fisher, C.A.J., Kobayashi, S., Ikuhara, Y.H., Fujiwara, Y., Hoshikawa, K., Moriwake, H., Kohama, K., Iba, H., Ikuhara, Y.

Acta Materialia　156　379-388　2018/09

DOI： 10.1016/j.actamat.2018.06.006 　

ISSN： 1359-6454
Site-Selective Analysis of Nickel-Substituted Li-Rich Layered Material: Migration and Role of Transition Metal at Charging and Discharging Peer-reviewed

Komatsu, H., Minato, T., Matsunaga, T., Shimoda, K., Kawaguchi, T., Fukuda, K., Nakanishi, K., Tanida, H., Kobayashi, S., Hirayama, T., Ikuhara, Y., Arai, H., Ukyo, Y., Uchimoto, Y., Matsubara, E., Ogumi, Z.

Journal of Physical Chemistry C　122　(35)　20099-20107　2018/09

DOI： 10.1021/acs.jpcc.8b05539 　

ISSN： 1932-7455 1932-7447
Direct Imaging for Single Molecular Chain of Surfactant on CeO₂ Nanocrystals Peer-reviewed

Hao, X., Chen, C., Saito, M., Yin, D., Inoue, K., Takami, S., Adschiri, T., Ikuhara, Y.

Small　14　(31)　2018/08/02

DOI： 10.1002/smll.201801093 　

ISSN： 1613-6829 1613-6810
First-principles study in an inter-granular glassy film model of silicon nitride

Ching, W.-Y., Yoshiya, M., Adhikari, P., Rulis, P., Ikuhara, Y., Tanaka, I.

Journal of the American Ceramic Society　101　(7)　2673-2688　2018/07
Publisher: WILEY
DOI： 10.1111/jace.15538 　

ISSN： 1551-2916 0002-7820
Microscopic mechanism of biphasic interface relaxation in lithium iron phosphate after delithiation Peer-reviewed

Kobayashi, S., Kuwabara, A., Fisher, C.A.J., Ukyo, Y., Ikuhara, Y.

Nature Communications　9　(1)　2863　2018/07

DOI： 10.1038/s41467-018-05241-1 　

ISSN： 2041-1723
Large thickness dependence of the carrier mobility in a transparent oxide semiconductor, La-doped BaSnO₃ Peer-reviewed

Sanchela, A.V., Wei, M., Zensyo, H., Feng, B., Lee, J., Kim, G., Jeen, H., Ikuhara, Y., Ohta, H.

Applied Physics Letters　112　(23)　232102　2018/06

DOI： 10.1063/1.5033326 　

ISSN： 0003-6951
Double thermoelectric power factor of a 2D electron system

Zhang, Y., Feng, B., Hayashi, H., Chang, C.-P., Sheu, Y.-M., Tanaka, I., Ikuhara, Y., Ohta, H.

Nature Communications　9　(1)　2224　2018/06
Publisher: NATURE PUBLISHING GROUP
DOI： 10.1038/s41467-018-04660-4 　

ISSN： 2041-1723
Structure of the basal edge dislocation in ZnO Peer-reviewed

Nakamura, A., Tochigi, E., Nagahara, R., Furushima, Y., Oshima, Y., Ikuhara, Y., Yokoi, T., Matsunaga, K.

Crystals　8　(3)　2018/03

DOI： 10.3390/cryst8030127 　

ISSN： 2073-4352
Multiphase nanodomains in a strained BaTiO3 film on a GdScO3 substrate Peer-reviewed

Shunsuke Kobayashi, Kazutoshi Inoue, Takeharu Kato, Yuichi Ikuhara, Takahisa Yamamoto

Journal of Applied Physics　123　(6)　2018/02/14

DOI： 10.1063/1.5012545 　

ISSN： 1089-7550 0021-8979

eISSN： 1089-7550
Stable Magnetic Skyrmion States at Room Temperature Confined to Corrals of Artificial Surface Pits Fabricated by a Focused Electron Beam Peer-reviewed

Takao Matsumoto, Yeong Gi So, Yuji Kohno, Yuichi Ikuhara, Naoya Shibata

Nano Letters　18　(2)　754-762　2018/02/14

DOI： 10.1021/acs.nanolett.7b03967 　

ISSN： 1530-6984

eISSN： 1530-6992
Attainment of 40.5 pm spatial resolution using 300 kV scanning transmission electron microscope equipped with fifth-order aberration corrector Peer-reviewed

Shigeyuki Morishita, Ryo Ishikawa, Yuji Kohno, Hidetaka Sawada, Naoya Shibata, Yuichi Ikuhara

Microscopy　67　(1)　46-50　2018/02/01

DOI： 10.1093/jmicro/dfx122 　

ISSN： 2050-5698

eISSN： 2050-5701
One-angstrom-resolution element mapping by phase contrast ARHVEM technique

Iwamoto, C., Shen, X.Q., Okumura, H., Matsuhata, H., Ikuhara, Y.

Microscopy of Semiconducting Materials 2003　2018

DOI： 10.1201/9781351074636 　
Review: microstructure-development mechanism during sintering in polycrystalline zirconia Peer-reviewed

Matsui, K., Yoshida, H., Ikuhara, Y.

International Materials Reviews　63　(6)　375-406　2018

DOI： 10.1080/09506608.2017.1402424 　

ISSN： 1743-2804 0950-6608
Hierarchically structured thermoelectric materials in quaternary system cu-zn-sn-s featuring a mosaic-type nanostructure Peer-reviewed

Li, C., Shen, Y., Huang, R., Kumamoto, A., Chen, S., Dai, C., Yoshiya, M., Fujii, S., Funai, K., Fisher, C.A.J., Wang, Y., Qi, R., Duan, C.-G., Pan, L., Chu, J., Hirayama, T., Ikuhara, Y.

ACS Applied Nano Materials　1　(6)　2579-2588　2018

DOI： 10.1021/acsanm.8b00278 　

ISSN： 2574-0970
Interfacial atomic structures of single-phase Li₂MnO₃ thin film with superior initial charge-discharge behavior Peer-reviewed

Sugawara, Y., Taminato, S., Hirayama, T., Hirayama, M., Kanno, R., Ukyo, Y., Ikuhara, Y.

Journal of the Electrochemical Society　165　(2)　A55-A60　2018

DOI： 10.1149/2.0261802jes 　

ISSN： 1945-7111 0013-4651
Effects of an oxygen potential gradient and water vapor on mass transfer in polycrystalline alumina at high temperatures Peer-reviewed

Matsudaira, T., Kitaoka, S., Shibata, N., Ikuhara, Y., Takeuchi, M., Ogawa, T.

Acta Materialia　151　21-30　2018

DOI： 10.1016/j.actamat.2018.03.021 　

ISSN： 1359-6454
Dissociation reaction of the 1/3 〈1101 〉 edge dislocation in α-Al₂O₃ Peer-reviewed

Tochigi, E., Mizoguchi, T., Okunishi, E., Nakamura, A., Shibata, N., Ikuhara, Y.

Journal of Materials Science　53　(11)　8049-8058　2018

DOI： 10.1007/s10853-018-2133-7 　

ISSN： 1573-4803 0022-2461
Atomic-scale nanostructures by advanced electron microscopy and informatics Peer-reviewed

Mizoguchi, T., Kiyohara, S., Ikuhara, Y., Shibata, N.

Nanoinformatics　157-178　2018

DOI： 10.1007/978-981-10-7617-6_8 　
Impact of a surface TiO₂ atomic sheet on the electronic transport properties of LaAlO₃/SrTiO₃ heterointerfaces Peer-reviewed

Ohsawa, T., Saito, M., Shimizu, R., Iwaya, K., Shiraki, S., Ikuhara, Y., Hitosugi, T.

Applied Physics Letters　113　(14)　141602　2018

DOI： 10.1063/1.5046876 　

ISSN： 0003-6951
< 100 > Dislocation at a {20} low-angle grain boundary in LiNbO3 Peer-reviewed

Yuho Furushima, Atsutomo Nakamura, Eita Tochigi, Yuichi Ikuhara, Kazuaki Toyoura, Katsuyuki Matsunaga

JOURNAL OF MATERIALS SCIENCE　53　(1)　333-344　2018/01

DOI： 10.1007/s10853-017-1532-5 　

ISSN： 0022-2461

eISSN： 1573-4803
Atomic-scale structure relaxation, chemistry and charge distribution of dislocation cores in SrTiO<inf>3</inf> Peer-reviewed

Peng Gao, Ryo Ishikawa, Bin Feng, Akihito Kumamoto, Naoya Shibata, Yuichi Ikuhara

Ultramicroscopy　184　217-224　2018/01

DOI： 10.1016/j.ultramic.2017.09.006 　

ISSN： 0304-3991

eISSN： 1879-2723
Picometer-scale atom position analysis in annular bright-field STEM imaging Peer-reviewed

Peng Gao, Akihito Kumamoto, Ryo Ishikawa, Nathan Lugg, Naoya Shibata, Yuichi Ikuhara

Ultramicroscopy　184　177-187　2018/01

DOI： 10.1016/j.ultramic.2017.09.001 　

ISSN： 0304-3991

eISSN： 1879-2723
Atomic-Scale Origin of the Quasi-One-Dimensional Metallic Conductivity in Strontium Niobates with Perovskite-Related Layered Structures Peer-reviewed

Chunlin Chen, Deqiang Yin, Kazutoshi Inoue, Frank Lichtenberg, Xiuliang Ma, Yuichi Ikuhara, Johannes Georg Bednorz

ACS Nano　11　(12)　12519-12525　2017/12/26

DOI： 10.1021/acsnano.7b06619 　

ISSN： 1936-086X 1936-0851

eISSN： 1936-086X
One-pot synthesis of a C/SiFeN(O)-based ceramic paper with in-situ generated hierarchical micro/nano-morphology Peer-reviewed

Cong Zhou, Claudia Fasel, Ryo Ishikawa, Markus Gallei, Yuichi Ikuhara, Stefan Lauterbach, Hans-Joachim Kleebe, Ralf Riedel, Emanuel Ionescu

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY　37　(16)　5193-5203　2017/12

DOI： 10.1016/j.jeurceramsoc.2017.03.007 　

ISSN： 0955-2219

eISSN： 1873-619X
Direct Observation of Oxygen Vacancy Distribution across Yttria-Stabilized Zirconia Grain Boundaries Peer-reviewed

Bin Feng, Nathan R. Lugg, Akihito Kumamoto, Yuichi Ikuhara, Naoya Shibata

ACS Nano　11　(11)　11376-11382　2017/11/28

DOI： 10.1021/acsnano.7b05943 　

ISSN： 1936-0851

eISSN： 1936-086X
Quantitative electric field mapping in thin specimens using a segmented detector: Revisiting the transfer function for differential phase contrast Peer-reviewed

Takehito Seki, Gabriel Sanchez-Santolino, Ryo Ishikawa, Scott D. Findlay, Yuichi Ikuhara, Naoya Shibata

ULTRAMICROSCOPY　182　258-263　2017/11

DOI： 10.1016/j.ultramic.2017.07.013 　

ISSN： 0304-3991

eISSN： 1879-2723
Realization of Large Electric Polarization and Strong Magnetoelectric Coupling in BiMn3Cr4O12 Peer-reviewed

Long Zhou, Jianhong Dai, Yisheng Chai, Huimin Zhang, Shuai Dong, Huibo Cao, Stuart Calder, Yunyu Yin, Xiao Wang, Xudong Shen, Zhehong Liu, Takashi Saito, Yuichi Shimakawa, Hajime Hojo, Yuichi Ikuhara, Masaki Azuma, Zhiwei Hu, Young Sun, Changqing Jin, Youwen Long

ADVANCED MATERIALS　29　(44)　2017/11

DOI： 10.1002/adma.201703435 　

ISSN： 0935-9648

eISSN： 1521-4095
Solid-phase epitaxial film growth and optical properties of a ferroelectric oxide, Sr2Nb2O7 Peer-reviewed

Yukio Nezu, Yu-Qiao Zhang, Chunlin Chen, Yuichi Ikuhara, Hiromichi Ohta

JOURNAL OF APPLIED PHYSICS　122　(13)　2017/10

DOI： 10.1063/1.4997813 　

ISSN： 0021-8979

eISSN： 1089-7550
Inversion domain boundaries in Mn and Al dual-doped ZnO: Atomic structure and electronic properties Peer-reviewed

Joshua Hoemke, Eita Tochigi, Tetsuya Tohei, Hidehiro Yoshida, Naoya Shibata, Yuichi Ikuhara, Yoshio Sakka

Journal of the American Ceramic Society　100　(9)　4252-4262　2017/09

DOI： 10.1111/jace.14931 　

ISSN： 0002-7820

eISSN： 1551-2916
Another origin of yield drop behavior in sapphire deformed via basal slip: Recombination of climb-dissociated partial dislocations Peer-reviewed

Atsutomo Nakamura, Katsuyuki Matsunaga, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara, K. Peter D. Lagerlof

SCRIPTA MATERIALIA　138　109-113　2017/09

DOI： 10.1016/j.scriptamat.2017.06.001 　

ISSN： 1359-6462
Ferroelectric domains and phase evolution in (Fe:) KTa <inf>1−x</inf> Nb <inf>x</inf> O <inf>3</inf> crystals Peer-reviewed

Hongyang Zhao, Kang Cai, Ziran Fan, Zhideng Huang, Zhibin Ma, Tingting Jia, Hideo Kimura, Yuguo Yang, Takao Matsumoto, Tetsuya Tohei, Naoya Shibata, Yuichi Ikuhara

Applied Surface Science　413　1-6　2017/08/15

DOI： 10.1016/j.apsusc.2017.04.003 　

ISSN： 0169-4332
Quantitative analysis of Li distributions in battery material Li1-xFePO4 using Fe M-2,M-3-edge and valence electron energy loss spectra Peer-reviewed

Shunsuke Kobayashi, Craig A. J. Fisher, Akihide Kuwabara, Yoshio Ukyo, Yuichi Ikuhara

MICROSCOPY　66　(4)　254-260　2017/08

DOI： 10.1093/jmicro/dfx012 　

ISSN： 2050-5698

eISSN： 2050-5701
Thermopower modulation clarification of the intrinsic effective mass in transparent oxide semiconductor BaSnO3 Peer-reviewed

Anup V. Sanchela, Takaki Onozato, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta

PHYSICAL REVIEW MATERIALS　1　(3)　2017/08

DOI： 10.1103/PhysRevMaterials.1.034603 　

ISSN： 2475-9953
Single-source-precursor synthesis and electromagnetic properties of novel RGO-SiCN ceramic nanocomposites Peer-reviewed

Xingmin Liu, Zhaoju Yu, Ryo Ishikawa, Lingqi Chen, Xiaowei Yin, Yuichi Ikuhara, Ralf Riedel

JOURNAL OF MATERIALS CHEMISTRY C　5　(31)　7950-7960　2017/08

DOI： 10.1039/c7tc00395a 　

ISSN： 2050-7526

eISSN： 2050-7534
Room-temperature dilute ferromagnetic dislocations in S r1-x M nxTi O3-δ Peer-reviewed

Ryo Ishikawa, Yoichi Shimbo, Issei Sugiyama, Nathan R. Lugg, Naoya Shibata, Yuichi Ikuhara

Physical Review B　96　(2)　2017/07/25

DOI： 10.1103/PhysRevB.96.024440 　

ISSN： 2469-9950

eISSN： 2469-9969
Direct Visualization of Local Electromagnetic Field Structures by Scanning Transmission Electron Microscopy Peer-reviewed

Naoya Shibata, Scott D. Findlay, Takao Matsumoto, Yuji Kohno, Takehito Seki, Gabriel Sanchez-Santolino, Yuichi Ikuhara

ACCOUNTS OF CHEMICAL RESEARCH　50　(7)　1502-1512　2017/07

DOI： 10.1021/acs.accounts.7b00123 　

ISSN： 0001-4842

eISSN： 1520-4898
Full picture discovery for mixed-fluorine anion effects on high-voltage spinel lithium nickel manganese oxide cathodes Peer-reviewed

Dae-wook Kim, Hiromasa Shiiba, Nobuyuki Zettsu, Tetsuya Yamada, Takeshi Kimijima, Gabriel Sanchez-Santolino, Ryo Ishikawa, Yuichi Ikuhara, Katsuya Teshima

NPG ASIA MATERIALS　9　2017/07

DOI： 10.1038/am.2017.90 　

ISSN： 1884-4049

eISSN： 1884-4057
Possible absence of critical thickness and size effect in ultrathin perovskite ferroelectric films Peer-reviewed

Peng Gao, Zhangyuan Zhang, Mingqiang Li, Ryo Ishikawa, Bin Feng, Heng Jui Liu, Yen Lin Huang, Naoya Shibata, Xiumei Ma, Shulin Chen, Jingmin Zhang, Kaihui Liu, En Ge Wang, Dapeng Yu, Lei Liao, Ying Hao Chu, Yuichi Ikuhara

Nature Communications　8　2017/06/06

DOI： 10.1038/ncomms15549 　

ISSN： 2041-1723

eISSN： 2041-1723
Three-Dimensional Visualization and Characterization of Polymeric Self-Assemblies by Transmission Electron Microtomography Peer-reviewed

Hiroshi Jinnai, Takeshi Higuchi, Xiaodong Zhuge, Akihito Kumamoto, Kees Joost Batenburg, Yuichi Ikuhara

ACCOUNTS OF CHEMICAL RESEARCH　50　(6)　1293-1302　2017/06

DOI： 10.1021/acs.accounts.7b00103 　

ISSN： 0001-4842

eISSN： 1520-4898
Relative Li-ion mobility mapping in Li<inf>0.33</inf>La<inf>0.56</inf>TiO<inf>3</inf> polycrystalline by electron backscatter diffraction and electrochemical strain microscopy Peer-reviewed

Shun Sasano, Ryo Ishikawa, Issei Sugiyama, Takuma Higashi, Teiichi Kimura, Yumi H. Ikuhara, Naoya Shibata, Yuichi Ikuhara

Applied Physics Express　10　(6)　2017/06

DOI： 10.7567/APEX.10.061102 　

ISSN： 1882-0778

eISSN： 1882-0786
Electric field imaging of single atoms Peer-reviewed

Naoya Shibata, Takehito Seki, Gabriel Sanchez-Santolino, Scott D. Findlay, Yuji Kohno, Takao Matsumoto, Ryo Ishikawa, Yuichi Ikuhara

NATURE COMMUNICATIONS　8　2017/05

DOI： 10.1038/ncomms15631 　

ISSN： 2041-1723
Single-source-precursor derived RGO/CNTs-SiCN ceramic nanocomposite with ultra-high electromagnetic shielding effectiveness Peer-reviewed

Xingmin Liu, Zhaoju Yu, Ryo Ishikawa, Lingqi Chen, Xiaofei Liu, Xiaowei Yin, Yuichi Ikuhara, Ralf Riedel

ACTA MATERIALIA　130　83-93　2017/05

DOI： 10.1016/j.actamat.2017.03.031 　

ISSN： 1359-6454

eISSN： 1873-2453
Thermoelectric phase diagram of the SrTiO3-SrNbO3 solid solution system Peer-reviewed

Yuqiao Zhang, Bin Feng, Hiroyuki Hayashi, Tetsuya Tohei, Isao Tanaka, Yuichi Ikuhara, Hiromichi Ohta

JOURNAL OF APPLIED PHYSICS　121　(18)　2017/05

DOI： 10.1063/1.4983359 　

ISSN： 0021-8979

eISSN： 1089-7550
Direct Observation of Impurity Segregation at Dislocation Cores in an Ionic Crystal Peer-reviewed

Eita Tochigi, Yuki Kezuka, Akiho Nakamura, Atsutomo Nakamura, Naoya Shibata, Yuichi Ikuhara

NANO LETTERS　17　(5)　2908-2912　2017/05

DOI： 10.1021/acs.nanolett.7b00115 　

ISSN： 1530-6984

eISSN： 1530-6992
Atomic level changes during capacity fade in highly oriented thin films of cathode material LiCoPO4 Peer-reviewed

Yumi H. Ikuhara, Xiang Gao, Craig A. J. Fisher, Akihide Kuwabara, Hiroki Moriwake, Keiichi Kohama, Hideki Iba, Yuichi Ikuhara

JOURNAL OF MATERIALS CHEMISTRY A　5　(19)　9329-9338　2017/05

DOI： 10.1039/c6ta10084h 　

ISSN： 2050-7488

eISSN： 2050-7496
Atomic structure and electronic properties of MgO grain boundaries in tunnelling magnetoresistive devices Peer-reviewed

Jonathan J. Bean, Mitsuhiro Saito, Shunsuke Fukami, Hideo Sato, Shoji Ikeda, Hideo Ohno, Yuichi Ikuhara, Keith P. McKenna

SCIENTIFIC REPORTS　7　2017/04

DOI： 10.1038/srep45594 　

ISSN： 2045-2322
Structure of < 110 >-tilt boundaries in cubic zirconia Peer-reviewed

Kazutoshi Inoue, Bin Feng, Naoya Shibata, Motoko Kotani, Yuichi Ikuhara

JOURNAL OF MATERIALS SCIENCE　52　(8)　4278-4287　2017/04

DOI： 10.1007/s10853-016-0682-1 　

ISSN： 0022-2461

eISSN： 1573-4803
Reactive Solid-Phase Epitaxy and Electrical Conductivity of Layered Sodium Manganese Oxide Films Peer-reviewed

Shota Katayama, Takayoshi Katase, Tetsuya Tohei, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta

CRYSTAL GROWTH & DESIGN　17　(4)　1849-1853　2017/04

DOI： 10.1021/acs.cgd.6b01810 　

ISSN： 1528-7483

eISSN： 1528-7505
Atomic scale imaging of structural changes in solid electrolyte lanthanum lithium niobate upon annealing Peer-reviewed

Xiaobing Hu, Craig A. J. Fisher, Shunsuke Kobayashi, Yumi H. Ikuhara, Yasuyuki Fujiwara, Keigo Hoshikawa, Hiroki Moriwake, Keiichi Kohama, Hideki Iba, Yuichi Ikuhara

ACTA MATERIALIA　127　211-219　2017/04

DOI： 10.1016/j.actamat.2017.01.028 　

ISSN： 1359-6454

eISSN： 1873-2453
Transparent polycrystalline cubic silicon nitride Peer-reviewed

Norimasa Nishiyama, Ryo Ishikawa, Hiroaki Ohfuji, Hauke Marquardt, Alexander Kurnosov, Takashi Taniguchi, Byung-Nam Kim, Hidehiro Yoshida, Atsunobu Masuno, Jozef Bednarcik, Eleonora Kulik, Yuichi Ikuhara, Fumihiro Wakai, Tetsuo Irifune

SCIENTIFIC REPORTS　7　2017/03

DOI： 10.1038/srep44755 　

ISSN： 2045-2322
Direct-bonded aluminum on aluminum nitride substrates by transient liquid phase bonding Peer-reviewed

Yoshirou Kuromitsu, Yoshiyuki Nagatomo, Kazuhiro Akiyama, Naoya Shibata, Yuichi Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　125　(3)　165-167　2017/03

DOI： 10.2109/jcersj2.16235 　

ISSN： 1882-0743

eISSN： 1348-6535
Study on the deterioration mechanism of layered rock-salt electrodes using epitaxial thin films Li(Ni, Co, Mn)0(2) and their Zr-O surface modified electrodes Peer-reviewed

Machiko Abe, Hideaki Iba, Kota Suzuki, Hiroaki Minamishima, Masaaki Hirayama, Kazuhisa Tamura, Jun'ichiro Mizuki, Tomohiro Saito, Yuichi Ikuhara, Ryoji Kanno

JOURNAL OF POWER SOURCES　345　108-119　2017/03

DOI： 10.1016/j.jpowsour.2017.01.103 　

ISSN： 0378-7753

eISSN： 1873-2755
Atomic-Scale Tracking of a Phase Transition from Spinel to Rocksalt in Lithium Manganese Oxide Peer-reviewed

Peng Gao, Ryo Ishikawa, Eita Tochigi, Akihito Kumamoto, Naoya Shibata, Yuichi Ikuhara

CHEMISTRY OF MATERIALS　29　(3)　1006-1013　2017/02

DOI： 10.1021/acs.chemmater.6b03659 　

ISSN： 0897-4756

eISSN： 1520-5002
Direct visualization of lithium via annular bright field scanning transmission electron microscopy: a review Peer-reviewed

Scott David Findlay, Rong Huang, Ryo Ishikawa, Naoya Shibata, Yuichi Ikuhara

MICROSCOPY　66　(1)　3-14　2017/02

DOI： 10.1093/jmicro/dfw041 　

ISSN： 2050-5698

eISSN： 2050-5701
Mechanical force involved multiple fields switching of both local ferroelectric and magnetic domain in a Bi5Ti3FeO15 thin film Peer-reviewed

Tingting Jia, Hideo Kimura, Zhenxiang Cheng, Hongyang Zhao, Yoon-Hyun Kim, Minoru Osada, Takao Matsumoto, Naoya Shibata, Yuichi Ikuhara

NPG ASIA MATERIALS　9　2017/02

DOI： 10.1038/am.2017.3 　

ISSN： 1884-4049

eISSN： 1884-4057
Fracture behavior of the Sigma 13 grain boundary of alpha-alumina Peer-reviewed

2017 5TH INTERNATIONAL WORKSHOP ON LOW TEMPERATURE BONDING FOR 3D INTEGRATION (LTB-3D)　63　2017
Atomic structure of Ti-doped alumina grain boundaries fabricated in air and reducing atmosphere Peer-reviewed

Saki Ishihara, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara

2017 5TH INTERNATIONAL WORKSHOP ON LOW TEMPERATURE BONDING FOR 3D INTEGRATION (LTB-3D)　79-79　2017

DOI： 10.23919/LTB-3D.2017.7947475 　
Why is sodium-intercalated graphite unstable? Peer-reviewed

Hiroki Moriwake, Akihide Kuwabara, Craig A. J. Fisher, Yuichi Ikuhara

RSC ADVANCES　7　(58)　36550-36554　2017

DOI： 10.1039/c7ra06777a 　

ISSN： 2046-2069

eISSN： 2046-2069
Atomic scale imaging of structural variations in La(1-x)/3LixNbO3 (0 <= x <= 0.13) solid electrolytes Peer-reviewed

Xiaobing Hu, Shunsuke Kobayashi, Yumi H. Ikuhara, Craig A. J. Fisher, Yasuyuki Fujiwara, Keigo Hoshikawa, Hiroki Moriwake, Keiichi Kohama, Hideki Iba, Yuichi Ikuhara

ACTA MATERIALIA　123　167-176　2017/01

DOI： 10.1016/j.actamat.2016.10.025 　

ISSN： 1359-6454

eISSN： 1873-2453
A Novel Class of Multiferroic Material, Bi4Ti3O12 center dot nBiFeO(3) with Localized Magnetic Ordering Evaluated from Their Single Crystals Peer-reviewed

Hongyang Zhao, Kang Cai, Zhenxiang Cheng, Tingting Jia, Hideo Kimura, Zhibin Ma, Qiuming Fu, Zhideng Huang, Takao Matsumoto, Tetsuya Tohei, Naoya Shibata, Yuichi Ikuhara

ADVANCED ELECTRONIC MATERIALS　3　(1)　2017/01

DOI： 10.1002/aelm.201600254 　

ISSN： 2199-160X
Investigation of V-shaped extended defects in a 4H-SiC epitaxial film Peer-reviewed

Eita Tochigi, Hirofumi Matsuhata, Hirotaka Yamaguchi, Takashi Sekiguchi, Hajime Okumura, Yuichi Ikuhara

PHILOSOPHICAL MAGAZINE　97　(9)　657-670　2017

DOI： 10.1080/14786435.2016.1275869 　

ISSN： 1478-6435

eISSN： 1478-6443
Solid-liquid phase epitaxial growth of Li4Ti5O12 thin film Peer-reviewed

Ning Li, Takayoshi Katase, Yanbei Zhu, Takao Matsumoto, Tomonari Umemura, Yuichi Ikuhara, Hiromichi Ohta

APPLIED PHYSICS EXPRESS　9　(12)　2016/12

DOI： 10.7567/APEX.9.125501 　

ISSN： 1882-0778

eISSN： 1882-0786
Mathematical analysis and STEM observations of arrangement of structural units in < 001 > symmetrical tilt grain boundaries Peer-reviewed

Kazutoshi Inoue, Mitsuhiro Saito, Chunlin Chen, Motoko Kotani, Yuichi Ikuhara

MICROSCOPY　65　(6)　479-487　2016/12

DOI： 10.1093/jmicro/dfw034 　

ISSN： 2050-5698

eISSN： 2050-5701
Direct observation of individual dislocation interaction processes with grain boundaries Peer-reviewed

Shun Kondo, Tasuku Mitsuma, Naoya Shibata, Yuichi Ikuhara

SCIENCE ADVANCES　2　(11)　2016/11

DOI： 10.1126/sciadv.1501926 　

ISSN： 2375-2548
A Metal-Insulator Transition of the Buried MnO2 Monolayer in Complex Oxide Heterostructure Peer-reviewed

Heng-Jui Liu, Jheng-Cyuan Lin, Yue-Wen Fang, Jing-Ching Wang, Bo-Chao Huang, Xiang Gao, Rong Huang, Philip R. Dean, Peter D. Hatton, Yi-Ying Chin, Hong-Ji Lin, Chien-Te Chen, Yuichi Ikuhara, Ya-Ping Chiu, Chia-Seng Chang, Chun-Gang Duan, Qing He, Ying-Hao Chu

ADVANCED MATERIALS　28　(41)　9142-+　2016/11

DOI： 10.1002/adma.201602281 　

ISSN： 0935-9648

eISSN： 1521-4095
An artificial photosynthesis anode electrode composed of a nanoparticulate photocatalyst film in a visible light responsive GaN-ZnO solid solution system Peer-reviewed

Yoshihiko Imanaka, Toshihisa Anazawa, Toshio Manabe, Hideyuki Amada, Sachio Ido, Fumiaki Kumasaka, Naoki Awaji, Gabriel Sanchez-Santolino, Ryo Ishikawa, Yuichi Ikuhara

SCIENTIFIC REPORTS　6　2016/10

DOI： 10.1038/srep35593 　

ISSN： 2045-2322
First principles calculation of thermal expansion coefficients of pure and Cr doped alpha-alumina crystals Peer-reviewed

Tetsuya Tohei, Yuito Watanabe, Hak-Sung Lee, Yuichi Ikuhara

JOURNAL OF APPLIED PHYSICS　120　(14)　2016/10

DOI： 10.1063/1.4961720 　

ISSN： 0021-8979

eISSN： 1089-7550
Dislocation structures and electrical conduction properties of low angle tilt grain boundaries in LiNbO3 Peer-reviewed

Yuho Furushima, Atsutomo Nakamura, Eita Tochigi, Yuichi Ikuhara, Kazuaki Toyoura, Katsuyuki Matsunaga

JOURNAL OF APPLIED PHYSICS　120　(14)　2016/10

DOI： 10.1063/1.4961706 　

ISSN： 0021-8979

eISSN： 1089-7550
Single atom visibility in STEM optical depth sectioning Peer-reviewed

Ryo Ishikawa, Stephen J. Pennycook, Andrew R. Lupini, Scott D. Findlay, Naoya Shibata, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　109　(16)　2016/10

DOI： 10.1063/1.4965709 　

ISSN： 0003-6951

eISSN： 1077-3118
Enhanced Piezoelectric Response due to Polarization Rotation in Cobalt-Substituted BiFeO3 Epitaxial Thin Films Peer-reviewed

Keisuke Shimizu, Hajime Hojo, Yuichi Ikuhara, Masaki Azuma

ADVANCED MATERIALS　28　(39)　8639-8644　2016/10

DOI： 10.1002/adma.201602450 　

ISSN： 0935-9648

eISSN： 1521-4095
Jointed magnetic skyrmion lattices at a small-angle grain boundary directly visualized by advanced electron microscopy Peer-reviewed

Takao Matsumoto, Yeong-Gi So, Yuji Kohno, Hidetaka Sawada, Ryo Ishikawa, Yuichi Ikuhara, Naoya Shibata

SCIENTIFIC REPORTS　6　2016/10

DOI： 10.1038/srep35880 　

ISSN： 2045-2322
An experimental system combined with a micromachine and double-tilt TEM holder Peer-reviewed

Takaaki Sato, Eita Tochigi, Teruyasu Mizoguchi, Yuichi Ikuhara, Hiroyuki Fujita

MICROELECTRONIC ENGINEERING　164　43-47　2016/10

DOI： 10.1016/j.mee.2016.06.018 　

ISSN： 0167-9317

eISSN： 1873-5568
Atomic-Scale Observations of (010) LiFePO4 Surfaces Before and After Chemical Delithiation Peer-reviewed

Shunsuke Kobayashi, Craig A. J. Fisher, Takeharu Kato, Yoshio Ukyo, Tsukasa Hirayama, Yuichi Ikuhara

NANO LETTERS　16　(9)　5409-5414　2016/09

DOI： 10.1021/acs.nanolett.6b01689 　

ISSN： 1530-6984

eISSN： 1530-6992
Crystal and electronic structure changes during the charge-discharge process of Na4Co3(PO4)(2)P2O7 Peer-reviewed

Hiroki Moriwake, Akihide Kuwabara, Craig Aj. Fisher, Masafumi Nose, Hideki Nakayama, Shinji Nakanishi, Hideki Iba, Yuichi Ikuhara

JOURNAL OF POWER SOURCES　326　220-225　2016/09

DOI： 10.1016/j.jpowsour.2016.07.006 　

ISSN： 0378-7753

eISSN： 1873-2755
Structure and energetics of nanotwins in cubic boron nitrides Peer-reviewed

Shijian Zheng, Ruifeng Zhang, Rong Huang, Takashi Taniguchi, Xiuliang Ma, Yuichi Ikuhara, Irene J. Beyerlein

APPLIED PHYSICS LETTERS　109　(8)　2016/08

DOI： 10.1063/1.4961240 　

ISSN： 0003-6951

eISSN： 1077-3118
Dependence of Structural Defects in Li2MnO3 on Synthesis Temperature Peer-reviewed

Toshiyuki Matsunaga, Hideyuki Komatsu, Keiji Shimoda, Taketoshi Minato, Masao Yonemura, Takashi Kamiyama, Shunsuke Kobayash, Takeharu Kato, Tsukasa Hirayama, Yuichi Ikuhara, Hajime Arai, Yoshio Ukyo, Yoshiharu Uchimoto, Zempachi Ogumi

CHEMISTRY OF MATERIALS　28　(12)　4143-4150　2016/06

DOI： 10.1021/acs.chemmater.5b05041 　

ISSN： 0897-4756

eISSN： 1520-5002
Structural Understanding of Superior Battery Properties of Partially Ni-Doped Li2MnO3 as Cathode Material Peer-reviewed

Toshiyuki Matsunaga, Hideyuki Komatsu, Keiji Shimoda, Taketoshi Minato, Masao Yonemura, Takashi Kamiyama, Shunsuke Kobayash, Takeharu Kato, Tsukasa Hirayama, Yuichi Ikuhara, Hajime Arai, Yoshio Ukyo, Yoshiharu Uchimoto, Zempachi Ogumi

JOURNAL OF PHYSICAL CHEMISTRY LETTERS　7　(11)　2063-2067　2016/06

DOI： 10.1021/acs.jpclett.6b00587 　

ISSN： 1948-7185
Sintering characteristics and thermoelectric properties of Mn-Al co-doped ZnO ceramics Peer-reviewed

Joshua Hoemke, Atta Ullah Khan, Hidehiro Yoshida, Takao Mori, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara, Yoshio Sakka

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　124　(5)　515-522　2016/05

DOI： 10.2109/jcersj2.15282 　

ISSN： 1882-0743

eISSN： 1348-6535
Crystalline Grain Interior Configuration Affects Lithium Migration Kinetics in Li-Rich Layered Oxide Peer-reviewed

Haijun Yu, Yeong-Gi So, Akihide Kuwabara, Eita Tochigi, Naoya Shibata, Tetsuichi Kudo, Haoshen Zhou, Yuichi Ikuhara

NANO LETTERS　16　(5)　2907-2915　2016/05

DOI： 10.1021/acs.nanolett.5b03933 　

ISSN： 1530-6984

eISSN： 1530-6992
Adsorption sites of single noble metal atoms on the rutile TiO2 (110) surface influenced by different surface oxygen vacancies Peer-reviewed

Katsuyuki Matsunaga, Teng-Yuan Chang, Ryo Ishikawa, Qian Dong, Kazuaki Toyoura, Atsutomo Nakamura, Yuichi Ikuhara, Naoya Shibata

JOURNAL OF PHYSICS-CONDENSED MATTER　28　(17)　2016/05

DOI： 10.1088/0953-8984/28/17/175002 　

ISSN： 0953-8984

eISSN： 1361-648X
Rational Low-Temperature Synthesis of Ultrasmall Nanocrystalline Manganese Binary Oxide Catalysts under Controlled Metal Cation Hydration in Organic Media Peer-reviewed

Yumi Miyamoto, Yoshiyuki Kuroda, Tsubasa Uematsu, Hiroyuki Oshikawa, Naoya Shibata, Yuichi Ikuhara, Kosuke Suzuki, Mitsuhiro Hibino, Kazuya Yamaguchi, Noritaka Mizuno

CHEMNANOMAT　2　(4)　297-306　2016/04

DOI： 10.1002/cnma.201600034 　

eISSN： 2199-692X
Atomic mechanism of polarization-controlled surface reconstruction in ferroelectric thin films Peer-reviewed

Peng Gao, Heng-Jui Liu, Yen-Lin Huang, Ying-Hao Chu, Ryo Ishikawa, Bin Feng, Ying Jiang, Naoya Shibata, En-Ge Wang, Yuichi Ikuhara

NATURE COMMUNICATIONS　7　2016/04

DOI： 10.1038/ncomms11318 　

ISSN： 2041-1723
Atomic structures of a liquid-phase bonded metal/nitride heterointerface Peer-reviewed

Akihito Kumamoto, Naoya Shibata, Kei-ichiro Nayuki, Tetsuya Tohei, Nobuyuki Terasaki, Yoshiyuki Nagatomo, Toshiyuki Nagase, Kazuhiro Akiyama, Yoshirou Kuromitsu, Yuichi Ikuhara

SCIENTIFIC REPORTS　6　2016/03

DOI： 10.1038/srep22936 　

ISSN： 2045-2322
Atomically ordered solute segregation behaviour in an oxide grain boundary Peer-reviewed

Bin Feng, Tatsuya Yokoi, Akihito Kumamoto, Masato Yoshiya, Yuichi Ikuhara, Naoya Shibata

NATURE COMMUNICATIONS　7　2016/03

DOI： 10.1038/ncomms11079 　

ISSN： 2041-1723
The Band Structure of Polycrystalline Al2O3 and Its Influence on Transport Phenomena Peer-reviewed

Arthur H. Heuer, Maryam Zahiri Azar, Hannes Guhl, Matthew Foulkes, Brian Gleeson, Tsubasa Nakagawa, Yuichi Ikuhara, Mike W. Finnis

JOURNAL OF THE AMERICAN CERAMIC SOCIETY　99　(3)　733-747　2016/03

DOI： 10.1111/jace.14149 　

ISSN： 0002-7820

eISSN： 1551-2916
Atomic-Scale Structure and Local Chemistry of CoFeB-MgO Magnetic Tunnel Junctions Peer-reviewed

Zhongchang Wang, Mitsuhiro Saito, Keith P. McKenna, Shunsuke Fukami, Hideo Sato, Shoji Ikeda, Hideo Ohno, Yuichi Ikuhara

NANO LETTERS　16　(3)　1530-1536　2016/03

DOI： 10.1021/acs.nanolett.5b03627 　

ISSN： 1530-6984

eISSN： 1530-6992
Atomic structures and oxygen dynamics of CeO2 grain boundaries Peer-reviewed

Bin Feng, Issei Sugiyama, Hajime Hojo, Hiromichi Ohta, Naoya Shibata, Yuichi Ikuhara

SCIENTIFIC REPORTS　6　2016/02

DOI： 10.1038/srep20288 　

ISSN： 2045-2322
Direct observation of Sigma 7 domain boundary core structure in magnetic skyrmion lattice Peer-reviewed

Takao Matsumoto, Yeong-Gi So, Yuji Kohno, Hidetaka Sawada, Yuichi Ikuhara, Naoya Shibata

SCIENCE ADVANCES　2　(2)　2016/02

DOI： 10.1126/sciadv.1501280 　

ISSN： 2375-2548
Interfacial Atomic Structure of Twisted Few-Layer Graphene Peer-reviewed

Ryo Ishikawa, Nathan R. Lugg, Kazutoshi Inoue, Hidetaka Sawada, Takashi Taniguchi, Naoya Shibata, Yuichi Ikuhara

SCIENTIFIC REPORTS　6　2016/02

DOI： 10.1038/srep21273 　

ISSN： 2045-2322
Orientation control of LiCoO2 epitaxial thin films on metal substrates Peer-reviewed

Susumu Shiraki, Yoshitaka Takagi, Ryota Shimizu, Tohru Suzuki, Masakazu Haruta, Yukio Sato, Yuichi Ikuhara, Taro Hitosugi

THIN SOLID FILMS　600　175-178　2016/02

DOI： 10.1016/j.tsf.2016.01.032 　

ISSN： 0040-6090
Patterning oxide nanopillars at the atomic scale by phase transformation

Chunlin Chen, Frank Lichtenberg, Yuichi Ikuhara, Johannes Georg Bednorz

Materials Science and Technology Conference and Exhibition 2016, MS and T 2016　2　1233-1237　2016
Publisher: Association for Iron and Steel Technology, AISTECH
Atom-resolved STEM-EDS Mapping of a Liquid-phase Bonded Metal/Nitride Heterointerface

Kumamoto Akihito, Shibata Naoya, Nayuki Kei-ichiro, Tohei Tetsuya, Ikuhara Yuichi, Terasaki Nobuyuki, Nagatomo Yoshiyuki, Nagase Toshiyuki, Akiyama Kazuhiro, Kuromitsu Yoshirou

Materia Japan　55　(12)　611-611　2016
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.55.611 　
Complex Point Defect Structure in Cubic Boron Nitride

Ishikawa Ryo, Shibata Naoya, Ikuhara Yuichi, Oba Fumiyasu, Findlay Scott D., Taniguchi Takashi, Tanaka Isao

Materia Japan　55　(12)　609-609　2016
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.55.609 　
Chirality specific and spatially uniform synthesis of single-walled carbon nanotubes from a sputtered Co-W bimetallic catalyst Peer-reviewed

Hua An, Akihito Kumamoto, Hiroki Takezaki, Shinnosuke Ohyama, Yang Qian, Taiki Inoue, Yuichi Ikuhara, Shohei Chiashi, Rong Xiang, Shigeo Maruyama

NANOSCALE　8　(30)　14523-14529　2016

DOI： 10.1039/c6nr02749k 　

ISSN： 2040-3364

eISSN： 2040-3372
Synthesis of subnanometer-diameter vertically aligned single-walled carbon nanotubes with copper-anchored cobalt catalysts Peer-reviewed

Kehang Cui, Akihito Kumamoto, Rong Xiang, Hua An, Benjamin Wang, Taiki Inoue, Shohei Chiashi, Yuichi Ikuhara, Shigeo Maruyama

NANOSCALE　8　(3)　1608-1617　2016

DOI： 10.1039/c5nr06007a 　

ISSN： 2040-3364

eISSN： 2040-3372
Microstructural Analysis and Thermoelectric Properties of Sn-Al co-doped ZnO Ceramics Peer-reviewed

Joshua Hoemke, Atta Ullah Khan, Hidehiro Yoshida, Takao Mori, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara, Yoshio Sakka

FRONTIERS IN MATERIALS SCIENCE (FMS2015)　1763　2016

DOI： 10.1063/1.4961357 　

ISSN： 0094-243X
Microstructures and improved J(c)-H characteristics of Cl-containing YBCO thin films prepared by the fluorine-free MOD method Peer-reviewed

Takanori Motoki, Jun-ichi Shimoyama, Hiraku Ogino, Kohji Kishio, Jiyoung Roh, Tetsuya Tohei, Yuichi Ikuhara, Shigeru Horii, Toshiya Doi, Genki Honda, Tatsuoki Nagaishi

SUPERCONDUCTOR SCIENCE & TECHNOLOGY　29　(1)　2016/01

DOI： 10.1088/0953-2048/29/1/015006 　

ISSN： 0953-2048

eISSN： 1361-6668
Low-temperature degradation in yttria-stabilized tetragonal zirconia polycrystal doped with small amounts of alumina: Effect of grain-boundary energy Peer-reviewed

Koji Matsui, Kazuto Nakamura, Akihito Kumamoto, Hidehiro Yoshida, Yuichi Ikuhara

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY　36　(1)　155-162　2016/01

DOI： 10.1016/j.jeurceramsoc.2015.09.016 　

ISSN： 0955-2219

eISSN： 1873-619X
Band engineering of perovskite-type transition metal oxynitrides for photocatalytic overall water splitting Peer-reviewed

Chengsi Pan, Tsuyoshi Takata, Kazunori Kumamoto, Su Su Khine Ma, Koichiro Ueda, Tsutomu Minegishi, Mamiko Nakabayashi, Takao Matsumoto, Naoya Shibata, Yuichi Ikuhara, Kazunari Domen

JOURNAL OF MATERIALS CHEMISTRY A　4　(12)　4544-4552　2016

DOI： 10.1039/c5ta10612e 　

ISSN： 2050-7488

eISSN： 2050-7496
Atomic Structure Characterization of Stacking Faults on the {1(1)over-bar00} Plane in alpha-Alumina by Scanning Transmission Electron Microscopy Peer-reviewed

Eita Tochigi, Scott D. Findlay, Eiji Okunishi, Teruyasu Mizoguchi, Atsutomo Nakamura, Naoya Shibata, Yuichi Ikuhara

FRONTIERS IN MATERIALS SCIENCE (FMS2015)　1763　2016

DOI： 10.1063/1.4961356 　

ISSN： 0094-243X
Control of the Metal-Insulator Transition at Complex Oxide Heterointerfaces through Visible Light Peer-reviewed

Jheng-Cyuan Lin, Vu Thanh Tra, Dung-Sheng Tsai, Tai-Te Lin, Po-Cheng Huang, Wei-Lun Hsu, Hui Jun Wu, Rong Huang, Nguyen Van Chien, Ryuji Yoshida, Jiunn-Yuan Lin, Yuichi Ikuhara, Ya-Ping Chiu, Shangjr Gwo, Din Ping Tsai, Jr-Hau He, Ying-Hao Chu

ADVANCED MATERIALS　28　(4)　764-770　2016/01

DOI： 10.1002/adma.201503499 　

ISSN： 0935-9648

eISSN： 1521-4095
First principles study of oxygen diffusion in a alpha-alumina {10(1)over-bar1} twin grain boundary Peer-reviewed

Tetsuya Tohei, Yuito Watanabe, Nobuaki Takahashi, Tsubasa Nakagawa, Naoya Shibata, Yuichi Ikuhara

PHILOSOPHICAL MAGAZINE　95　(35)　3985-3999　2015/12

DOI： 10.1080/14786435.2015.1110257 　

ISSN： 1478-6435

eISSN： 1478-6443
The Decomposition Formula of < 001 > Symmetrical Tilt Grain Boundaries Peer-reviewed

Kazutoshi Inoue, Mitsuhiro Saito, Zhongchang Wang, Motoko Kotani, Yuichi Ikuhara

MATERIALS TRANSACTIONS　56　(12)　1945-1952　2015/12

DOI： 10.2320/matertrans.M2015277 　

ISSN： 1345-9678

eISSN： 1347-5320
Solid-Phase Epitaxial Growth of A-Site-Ordered Perovskite Sr4-xErxCo4O12-delta: A Room Temperature Ferrimagnetic p-Type Semiconductor Peer-reviewed

Takayoshi Katase, Hidefumi Takahashi, Tetsuya Tohei, Yuki Suzuki, Michihiko Yamanouchi, Yuichi Ikuhara, Ichiro Terasaki, Hiromichi Ohta

ADVANCED ELECTRONIC MATERIALS　1　(12)　2015/12

DOI： 10.1002/aelm.201500199 　

ISSN： 2199-160X
High Electron Mobility of Nb-Doped SrTiO3 Films Stemming from Rod-Type Sr Vacancy Clusters Peer-reviewed

Shunsuke Kobayashi, Yuki Mizumukai, Tsuyoshi Ohnishi, Naoya Shibata, Yuichi Ikuhara, Takahisa Yamamoto

ACS NANO　9　(11)　10769-10777　2015/11

DOI： 10.1021/acsnano.5b05720 　

ISSN： 1936-0851

eISSN： 1936-086X
Tetragonal BiFeO3 on yttria-stabilized zirconia Peer-reviewed

Heng-Jui Liu, Yu-Hao Du, Peng Gao, Yen-Chin Huang, Hsiao-Wen Chen, Yi-Chun Chen, Hsiang-Lin Liu, Qing He, Yuichi Ikuhara, Ying-Hao Chu

APL MATERIALS　3　(11)　2015/11

DOI： 10.1063/1.4935310 　

ISSN： 2166-532X
Synthesis of ultrasmall Li-Mn spinel oxides exhibiting unusual ion exchange, electrochemical, and catalytic properties Peer-reviewed

Yumi Miyamoto, Yoshiyuki Kuroda, Tsubasa Uematsu, Hiroyuki Oshikawa, Naoya Shibata, Yuichi Ikuhara, Kosuke Suzuki, Mitsuhiro Hibino, Kazuya Yamaguchi, Noritaka Mizuno

SCIENTIFIC REPORTS　5　2015/10

DOI： 10.1038/srep15011 　

ISSN： 2045-2322
Patterning Oxide Nanopillars at the Atomic Scale by Phase Transformation Peer-reviewed

Chunlin Chen, Zhongchang Wang, Frank Lichtenberg, Yuichi Ikuhara, Johannes Georg Bednorz

NANO LETTERS　15　(10)　6469-6474　2015/10

DOI： 10.1021/acs.nanolett.5b01847 　

ISSN： 1530-6984

eISSN： 1530-6992
Atomic-scale assessment of the crystallization onset in silicon carbonitride Peer-reviewed

Gabriela Mera, Ryo Ishikawa, Emanuel Ionescu, Yuichi Ikuhara, Ralf Riedel

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY　35　(12)　3355-3362　2015/10

DOI： 10.1016/j.jeurceramsoc.2015.01.008 　

ISSN： 0955-2219

eISSN： 1873-619X
Melting of Pb Charge Glass and Simultaneous Pb-Cr Charge Transfer in PbCrO3 as the Origin of Volume Collapse Peer-reviewed

Runze Yu, Hajime Hojo, Tetsu Watanuki, Masaichiro Mizumaki, Takashi Mizokawa, Kengo Oka, Hyunjeong Kim, Akihiko Machida, Kouji Sakaki, Yumiko Nakamura, Akane Agui, Daisuke Mori, Yoshiyuki Inaguma, Martin Schlipf, Konstantin Z. Rushchanskii, Marjana Lezaic, Masaaki Matsuda, Jie Ma, Stuart Calder, Masahiko Isobe, Yuichi Ikuhara, Masaki Azuma

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY　137　(39)　12719-12728　2015/10

DOI： 10.1021/jacs.5b08216 　

ISSN： 0002-7863

eISSN： 1520-5126
Structural and electronic properties of Sigma 7 grain boundaries in alpha-Al2O3 Peer-reviewed

Hannes Guhl, Hak-Sung Lee, Paul Tangney, W. M. C. Foulkes, Arthur H. Heuer, Tsubasa Nakagawa, Yuichi Ikuhara, Michael W. Finnis

ACTA MATERIALIA　99　16-28　2015/10

DOI： 10.1016/j.actamat.2015.07.042 　

ISSN： 1359-6454

eISSN： 1873-2453
Control of normally on/off characteristics in hydrogenated diamond metal-insulator-semiconductor field-effect transistors

Liu, J.W., Liao, M.Y., Imura, M., Matsumoto, T., Shibata, N., Ikuhara, Y., Koide, Y.

Journal of Applied Physics　118　(11)　2015/09/21

DOI： 10.1063/1.4930294 　

ISSN： 1089-7550 0021-8979
Bulk metallic glassy surface native oxide: Its atomic structure, growth rate and electrical properties Peer-reviewed

Louzguine-Luzgin, D.V., Chen, C.L., Lin, L.Y., Wang, Z.C., Ketov, S.V., Miyama, M.J., Trifonov, A.S., Lubenchenko, A.V., Ikuhara, Y.

Acta Materialia　97　282-290　2015/09

DOI： 10.1016/j.actamat.2015.06.039 　

ISSN： 1359-6454
Solid Solution Domains at Phase Transition Front of LixNi0.5Mn1.5O4 Peer-reviewed

Hideyuki Komatsu, Hajime Arai, Yukinori Koyama, Kenji Sato, Takeharu Kato, Ryuji Yoshida, Haruno Murayama, Ikuma Takahashi, Yuki Orikasa, Katsutoshi Fukuda, Tsukasa Hirayama, Yuichi Ikuhara, Yoshio Ukyo, Yoshiharu Uchimoto, Zempachi Ogumi

ADVANCED ENERGY MATERIALS　5　(17)　2015/09

DOI： 10.1002/aenm.201500638 　

ISSN： 1614-6832

eISSN： 1614-6840
First Principles Calculation of Thermal Expansion of Carbon and Boron Nitrides Based on Quasi-Harmonic Approximation Peer-reviewed

Tetsuya Tohei, Hak-Sung Lee, Yuichi Ikuhara

MATERIALS TRANSACTIONS　56　(9)　1452-1456　2015/09

DOI： 10.2320/matertrans.MA201574 　

ISSN： 1345-9678

eISSN： 1347-5320
A Single-Atom-Thick TiO2 Nanomesh on an Insulating Oxide Peer-reviewed

Takeo Ohsawa, Mitsuhiro Saito, Ikutaro Hamada, Ryota Shimizu, Katsuya Iwaya, Susumu Shiraki, Zhongchang Wang, Yuichi Ikuhara, Taro Hitosugi

ACS NANO　9　(9)　8766-8772　2015/09

DOI： 10.1021/acsnano.5b02867 　

ISSN： 1936-0851

eISSN： 1936-086X
Two-dimensional electron gas at the Ti-diffused BiFeO3/SrTiO3 interface Peer-reviewed

Chunlin Chen, Shuhui Lv, Junjie Li, Zhongchang Wang, Xiaobin Liang, Yanxi Li, Dwight Viehland, Ken Nakajima, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　107　(3)　2015/07

DOI： 10.1063/1.4926732 　

ISSN： 0003-6951

eISSN： 1077-3118
Room-Temperature-Protonation-Driven On-Demand Metal-Insulator Conversion of a Transition Metal Oxide Peer-reviewed

Takayoshi Katase, Kenji Endo, Tetsuya Tohei, Yuichi Ikuhara, Hiromichi Ohta

ADVANCED ELECTRONIC MATERIALS　1　(7)　2015/07

DOI： 10.1002/aelm.201500063 　

ISSN： 2199-160X
Development of a monochromator for aberration-corrected scanning transmission electron microscopy Peer-reviewed

Masaki Mukai, Eiji Okunishi, Masanori Ashino, Kazuya Omoto, Tomohisa Fukuda, Akihiro Ikeda, Kazunori Somehara, Toshikatsu Kaneyama, Tomohiro Saitoh, Tsukasa Hirayama, Yuichi Ikuhara

MICROSCOPY　64　(3)　151-158　2015/06

DOI： 10.1093/jmicro/dfv001 　

ISSN： 2050-5698

eISSN： 2050-5701
Assessment of Strain-Generated Oxygen Vacancies Using SrTiO3 Bicrystals Peer-reviewed

Si-Young Choi, Sung-Dae Kim, Minseok Choi, Hak-Sung Lee, Jungho Ryu, Naoya Shibata, Teruyasu Mizoguchi, Eita Tochigi, Takahisa Yamamoto, Suk-Joong L. Kang, Yuichi Ikuhara

NANO LETTERS　15　(6)　4129-4134　2015/06

DOI： 10.1021/acs.nanolett.5b01245 　

ISSN： 1530-6984

eISSN： 1530-6992
Resolving 45-pm-separated Si-Si atomic columns with an aberration-corrected STEM Peer-reviewed

Hidetaka Sawada, Naoki Shimura, Fumio Hosokawa, Naoya Shibata, Yuichi Ikuhara

MICROSCOPY　64　(3)　213-217　2015/06

DOI： 10.1093/jmicro/dfv014 　

ISSN： 2050-5698

eISSN： 2050-5701
Dissociation of the 1/3 <(1)over-bar101 > dislocation and formation of the anion stacking fault on the basal plane in alpha-Al2O3 Peer-reviewed

Eita Tochigi, Atsutomo Nakamura, Teruyasu Mizoguchi, Naoya Shibata, Yuichi Ikuhara

ACTA MATERIALIA　91　152-161　2015/06

DOI： 10.1016/j.actamat.2015.02.033 　

ISSN： 1359-6454

eISSN： 1873-2453
Imaging of built-in electric field at a p-n junction by scanning transmission electron microscopy Peer-reviewed

Naoya Shibata, Scott D. Findlay, Hirokazu Sasaki, Takao Matsumoto, Hidetaka Sawada, Yuji Kohno, Shinya Otomo, Ryuichiro Minato, Yuichi Ikuhara

SCIENTIFIC REPORTS　5　2015/06

DOI： 10.1038/srep10040 　

ISSN： 2045-2322
Grain Boundary Plane Effect on Pr Segregation Site in ZnO sigma 13 [0001] Symmetric Tilt Grain Boundaries Peer-reviewed

Ji-Young Roh, Yukio Sato, Yuichi Ikuhara

JOURNAL OF THE AMERICAN CERAMIC SOCIETY　98　(6)　1932-1936　2015/06

DOI： 10.1111/jace.13536 　

ISSN： 0002-7820

eISSN： 1551-2916
Atomistic mechanisms of nonstoichiometry-induced twin boundary structural transformation in titanium dioxide Peer-reviewed

Rong Sun, Zhongchang Wang, Mitsuhiro Saito, Naoya Shibata, Yuichi Ikuhara

NATURE COMMUNICATIONS　6　2015/05

DOI： 10.1038/ncomms8120 　

ISSN： 2041-1723
Grain-boundary structures of stabilized zirconia

Naoya Shibata, Yuichi Ikuhara

New Research Trends of Fluorite-Based Oxide Materials: From Basic Chemistry and Materials Science to Engineering Applications　165-192　2015/04/01
Publisher: Nova Science Publishers, Inc.
On the quantitativeness of EDS STEM Peer-reviewed

Lugg, N.R., Kothleitner, G., Shibata, N., Ikuhara, Y.

Ultramicroscopy　151　150-159　2015/04
Publisher: Elsevier BV
DOI： 10.1016/j.ultramic.2014.11.029 　

ISSN： 1879-2723 0304-3991
Atomic-Scale Structure Evolution in a Quasi-Equilibrated Electrochemical Process of Electrode Materials for Rechargeable Batteries Peer-reviewed

Lin Gu, Dongdong Xiao, Yong-Sheng Hu, Hong Li, Yuichi Ikuhara

ADVANCED MATERIALS　27　(13)　2134-2149　2015/04

DOI： 10.1002/adma.201404620 　

ISSN： 0935-9648

eISSN： 1521-4095
A Complex Perovskite-Type Oxynitride: The First Photocatalyst for Water Splitting Operable at up to 600 nm Peer-reviewed

Chengsi Pan, Tsuyoshi Takata, Mamiko Nakabayashi, Takao Matsumoto, Naoya Shibata, Yuichi Ikuhara, Kazunari Domen

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION　54　(10)　2955-2959　2015/03

DOI： 10.1002/anie.201410961 　

ISSN： 1433-7851

eISSN： 1521-3773
Direct in situ observation of metallic glass deformation by real-time nano-scale indentation Peer-reviewed

Lin Gu, Limei Xu, Qingsheng Zhang, Deng Pan, Na Chen, Dmitri V. Louzguine-Luzgin, Ke-Fu Yao, Weihua Wang, Yuichi Ikuhara

SCIENTIFIC REPORTS　5　2015/03

DOI： 10.1038/srep09122 　

ISSN： 2045-2322
Domain boundaries and their influence on Li migration in solid-state electrolyte (La,Li)TiO3 Peer-reviewed

Hiroki Moriwake, Xiang Gao, Akihide Kuwabara, Craig A. J. Fisher, Teiichi Kimura, Yumi H. Ikuhara, Keiichi Kohama, Takeshi Tojigamori, Yuichi Ikuhara

JOURNAL OF POWER SOURCES　276　203-207　2015/02

DOI： 10.1016/j.jpowsour.2014.11.139 　

ISSN： 0378-7753

eISSN： 1873-2755
Phase Interface Structures in Li1+xRh2O4 Zero Strain Cathode Material Analyzed by Scanning Transmission Electron Microscopy Peer-reviewed

Akiho Nakamura, Yunpeng Gu, Kouji Taniguchi, Naoya Shibata, Hidenori Takagi, Yuichi Ikuhara

CHEMISTRY OF MATERIALS　27　(3)　938-943　2015/02

DOI： 10.1021/cm5042106 　

ISSN： 0897-4756

eISSN： 1520-5002
Misfit accommodation mechanism at the heterointerface between diamond and cubic boron nitride Peer-reviewed

Chunlin Chen, Zhongchang Wang, Takeharu Kato, Naoya Shibata, Takashi Taniguchi, Yuichi Ikuhara

NATURE COMMUNICATIONS　6　2015/02

DOI： 10.1038/ncomms7327 　

ISSN： 2041-1723
Simple and engineered process yielding carbon nanotube arrays with 1.2 x 10(13) cm(-2) wall density on conductive underlayer at 400 degrees C Peer-reviewed

Nuri Na, Dong Young Kim, Yeong-Gi So, Yuichi Ikuhara, Suguru Noda

CARBON　81　773-781　2015/01

DOI： 10.1016/j.carbon.2014.10.023 　

ISSN： 0008-6223

eISSN： 1873-3891
Cation ordering in A-site-deficient Li-ion conducting perovskites La(1-x)/3LixNbO3 Peer-reviewed

Xiang Gao, Craig A. J. Fisher, Yumi H. Ikuhara, Yasuyuki Fujiwara, Shunsuke Kobayashi, Hiroki Moriwake, Akihide Kuwabara, Keigo Hoshikawa, Keiichi Kohama, Hideki Iba, Yuichi Ikuhara

JOURNAL OF MATERIALS CHEMISTRY A　3　(7)　3351-3359　2015

DOI： 10.1039/c4ta07040b 　

ISSN： 2050-7488

eISSN： 2050-7496
A dislocation core in titanium dioxide and its electronic structure Peer-reviewed

Rong Sun, Zhongchang Wang, Naoya Shibata, Yuichi Ikuhara

RSC ADVANCES　5　(24)　18506-18510　2015

DOI： 10.1039/c4ra15278f 　

ISSN： 2046-2069
On the Periodicity of < 001 > Symmetrical Tilt Grain Boundaries Peer-reviewed

Kazutoshi Inoue, Mitsuhiro Saito, Zhongchang Wang, Motoko Kotani, Yuichi Ikuhara

MATERIALS TRANSACTIONS　56　(3)　281-287　2015

DOI： 10.2320/matertrans.M2014394 　

ISSN： 1345-9678

eISSN： 1347-5320
Double Columnar Structure with a Nanogradient Composite for Increased Oxygen Diffusivity and Reduction Activity Peer-reviewed

Young-Wan Ju, Junji Hyodo, Atsushi Inoishi, Shintaro Ida, Tetsuya Tohei, Yeong-Gi So, Yuichi Ikuhara, Tatsumi Ishihara

ADVANCED ENERGY MATERIALS　4　(17)　2014/12

DOI： 10.1002/aenm.201400783 　

ISSN： 1614-6832

eISSN： 1614-6840
Fabrication of all-solid-state battery using epitaxial Li CoO2 thin films Peer-reviewed

Susumu Shiraki, Hideki Oki, Yoshitaka Takagi, Tohru Suzuki, Akichika Kumatani, Ryota Shimizu, Masakazu Haruta, Takeo Ohsawa, Yukio Sato, Yuichi Ikuhara, Taro Hitosugi

JOURNAL OF POWER SOURCES　267　881-887　2014/12

DOI： 10.1016/j.jpowsour.2014.05.133 　

ISSN： 0378-7753

eISSN： 1873-2755
Atomic-scale structure and properties of highly stable antiphase boundary defects in Fe3O4 Peer-reviewed

Keith P. McKenna, Florian Hofer, Daniel Gilks, Vlado K. Lazarov, Chunlin Chen, Zhongchang Wang, Yuichi Ikuhara

NATURE COMMUNICATIONS　5　2014/12

DOI： 10.1038/ncomms6740 　

ISSN： 2041-1723
Morphology-Controlled Synthesis of Cubic Cesium Hydrogen Silicododecatungstate Crystals Peer-reviewed

Sayaka Uchida, Yoshiyuki Ogasawara, Toshiaki Maruichi, Akihito Kumamoto, Yuichi Ikuhara, Teppei Yamada, Hiroshi Kitagawa, Noritaka Mizuno

CRYSTAL GROWTH & DESIGN　14　(12)　6620-6626　2014/12

DOI： 10.1021/cg501575x 　

ISSN： 1528-7483

eISSN： 1528-7505
Atomic and electronic structure of the SrNbO3/SrNbO3.4 interface Peer-reviewed

Chunlin Chen, Shuhui Lv, Zhongchang Wang, Kazuto Akagi, Frank Lichtenberg, Yuichi Ikuhara, Johannes Georg Bednorz

APPLIED PHYSICS LETTERS　105　(22)　2014/12

DOI： 10.1063/1.4902970 　

ISSN： 0003-6951

eISSN： 1077-3118
Observations of crack propagation along a Zr-doped alumina grain boundary

A. Ishihara, S. Kondo, E. Tochigi, N. Shibata, Y. Ikuhara

Microscopy　63　(suppl 1)　i20.2-i21　2014/11
Publisher: Oxford University Press (OUP)
DOI： 10.1093/jmicro/dfu064 　

ISSN： 2050-5698

eISSN： 2050-5701
Structural Distortion and Compositional Gradients Adjacent to Epitaxial LiMn2O4 Thin Film Interfaces Peer-reviewed

Xiang Gao, Yumi H. Ikuhara, Craig A. J. Fisher, Hiroki Moriwake, Akihide Kuwabara, Hideki Oki, Keiichi Kohama, Ryuji Yoshida, Rong Huang, Yuichi Ikuhara

ADVANCED MATERIALS INTERFACES　1　(8)　2014/11

DOI： 10.1002/admi.201400143 　

ISSN： 2196-7350
Full Determination of Individual Reconstructed Atomic Columns in Intermixed Heterojunctions Peer-reviewed

Zhongchang Wang, Mitsuhiro Saito, Chunlin Chen, Yuya Matsubara, Kazunori Ueno, Masashi Kawasaki, Yuichi Ikuhara

NANO LETTERS　14　(11)　6584-6589　2014/11

DOI： 10.1021/nl503212j 　

ISSN： 1530-6984

eISSN： 1530-6992
Phase Boundary Structure of LixFePO4 Cathode Material Revealed by Atomic-Resolution Scanning Transmission Electron Microscopy Peer-reviewed

Akiho Nakamura, Sho Furutsuki, Shin-ichi Nishimura, Tetsuya Tohei, Yukio Sato, Naoya Shibata, Atsuo Yamada, Yuichi Ikuhara

CHEMISTRY OF MATERIALS　26　(21)　6178-6184　2014/11

DOI： 10.1021/cm5024986 　

ISSN： 0897-4756

eISSN： 1520-5002
Existence of basal oxygen vacancies on the rutile TiO2 (110) surface Peer-reviewed

Katsuyuki Matsunaga, Yusuke Tanaka, Kazuaki Toyoura, Atsutomo Nakamura, Yuichi Ikuhara, Naoya Shibata

PHYSICAL REVIEW B　90　(19)　2014/11

DOI： 10.1103/PhysRevB.90.195303 　

ISSN： 1098-0121

eISSN： 1550-235X
Spatially-resolved mapping of history-dependent coupled electrochemical and electronical behaviors of electroresistive NiO Peer-reviewed

Issei Sugiyama, Yunseok Kim, Stephen Jesse, Evgheni Strelcov, Amit Kumar, Alexander Tselev, Ehasan Kabiri Rahani, Vivek B. Shenoy, Takahisa Yamamoto, Naoya Shibata, Yuichi Ikuhara, Sergei V. Kalinin

SCIENTIFIC REPORTS　4　2014/10

DOI： 10.1038/srep06725 　

ISSN： 2045-2322
Nanoepitaxy of Anatase-type TiO2 on CeO2 Nanocubes Self-Assembled on a Si Substrate for Fabricating Well-Aligned Nanoscale Heterogeneous Interfaces Peer-reviewed

Daisuke Hojo, Takanari Togashi, Takeo Ohsawa, Mitsuhiro Saito, Zhongchang Wang, Yusuke Sakuda, Shunsuke Asahina, Yuichi Ikuhara, Taro Hitosugi, Tadafumi Adschiri

CRYSTAL GROWTH & DESIGN　14　(9)　4714-4720　2014/09

DOI： 10.1021/cg500821z 　

ISSN： 1528-7483

eISSN： 1528-7505
Structural evolution and enhanced piezoresponse in cobalt-substituted BiFeO3 thin films Peer-reviewed

Hajime Hojo, Ko Onuma, Yuichi Ikuhara, Masaki Azuma

APPLIED PHYSICS EXPRESS　7　(9)　2014/09

DOI： 10.7567/APEX.7.091501 　

ISSN： 1882-0778

eISSN： 1882-0786
Single adatom dynamics at monatomic steps of free-standing few-layer reduced graphene Peer-reviewed

Haixin Chang, Mitsuhiro Saito, Takuro Nagai, Yunye Liang, Yoshiyuki Kawazoe, Zhongchang Wang, Hongkai Wu, Koji Kimoto, Yuichi Ikuhara

SCIENTIFIC REPORTS　4　2014/08

DOI： 10.1038/srep06037 　

ISSN： 2045-2322
Subgrain boundary analyses in deformed orthopyroxene by TEM/STEM with EBSD-FIB sample preparation technique Peer-reviewed

Toshihiro Kogure, Hugues Raimbourg, Akihito Kumamoto, Eiko Fujii, Yuichi Ikuhara

EARTH PLANETS AND SPACE　66　2014/08

DOI： 10.1186/1880-5981-66-84 　

ISSN： 1880-5981
A New Sealed Lithium-Peroxide Battery with a Co-Doped Li2O Cathode in a Superconcentrated Lithium Bis(fluorosulfonyl)amide Electrolyte Peer-reviewed

Shin-ichi Okuoka, Yoshiyuki Ogasawara, Yosuke Suga, Mitsuhiro Hibino, Tetsuichi Kudo, Hironobu Ono, Koji Yonehara, Yasutaka Sumida, Yuki Yamada, Atsuo Yamada, Masaharu Oshima, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara, Noritaka Mizuno

SCIENTIFIC REPORTS　4　2014/07

DOI： 10.1038/srep05684 　

ISSN： 2045-2322
Atomic Structure and Kinetics of NASICON NaxV2(PO4)(3) Cathode for Sodium-Ion Batteries Peer-reviewed

Zelang Jian, Chenchen Yuan, Wenze Han, Xia Lu, Lin Gu, Xuekui Xi, Yong-Sheng Hu, Hong Li, Wen Chen, Dongfeng Chen, Yuichi Ikuhara, Liquan Chen

ADVANCED FUNCTIONAL MATERIALS　24　(27)　4265-4272　2014/07

DOI： 10.1002/adfm.201400173 　

ISSN： 1616-301X

eISSN： 1616-3028
Titanium enrichment and strontium depletion near edge dislocation in strontium titanate [001]/(110) low-angle tilt grain boundary Peer-reviewed

Takehara, K., Sato, Y., Tohei, T., Shibata, N., Ikuhara, Y.

Journal of Materials Science　49　(11)　3962-3969　2014/06

DOI： 10.1007/s10853-014-8034-5 　

ISSN： 1573-4803 0022-2461
Atomistic structure and segregation behavior in secondary structure and facet of Pr-doped ZnO Sigma 13 27.8 degrees [0001] tilt grain boundary Peer-reviewed

Ji-Young Roh, Yukio Sato, Yuichi Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　122　(1426)　381-385　2014/06

DOI： 10.2109/jcersj2.122.381 　

ISSN： 1882-0743

eISSN： 1348-6535
Systematic calculations of On (n=1 to 6) polytypes of LiCoO2 Peer-reviewed

Craig A. J. Fisher, Akihide Kuwabara, Hiroki Moriwake, Hideki Oki, Keiichi Kohama, Yuichi Ikuhara

PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS　8　(6)　545-548　2014/06

DOI： 10.1002/pssr.201409167 　

ISSN： 1862-6254

eISSN： 1862-6270
Selective impurity segregation at a near-I 5 pound grain boundary in MgO Peer-reviewed

Mitsuhiro Saito, Zhongchang Wang, Yuichi Ikuhara

JOURNAL OF MATERIALS SCIENCE　49　(11)　3956-3961　2014/06

DOI： 10.1007/s10853-014-8016-7 　

ISSN： 0022-2461

eISSN： 1573-4803
Large magnetoelectric coupling in magnetically short-range ordered Bi5Ti3FeO15 film Peer-reviewed

Hongyang Zhao, Hideo Kimura, Zhenxiang Cheng, Minoru Osada, Jianli Wang, Xiaolin Wang, Shixue Dou, Yan Liu, Jianding Yu, Takao Matsumoto, Tetsuya Tohei, Naoya Shibata, Yuichi Ikuhara

SCIENTIFIC REPORTS　4　2014/06

DOI： 10.1038/srep05255 　

ISSN： 2045-2322
Possible ferroelectricity in perovskite oxynitride SrTaO2N epitaxial thin films Peer-reviewed

Daichi Oka, Yasushi Hirose, Hideyuki Kamisaka, Tomoteru Fukumura, Kimikazu Sasa, Satoshi Ishii, Hiroyuki Matsuzaki, Yukio Sato, Yuichi Ikuhara, Tetsuya Hasegawa

SCIENTIFIC REPORTS　4　2014/05

DOI： 10.1038/srep04987 　

ISSN： 2045-2322
Epitaxial growth of Li4Ti5O12 thin films using RF magnetron sputtering Peer-reviewed

Akichika Kumatani, Susumu Shiraki, Yoshitaka Takagi, Tohru Suzuki, Takeo Ohsawa, Xiang Gao, Yuichi Ikuhara, Taro Hitosugi

JAPANESE JOURNAL OF APPLIED PHYSICS　53　(5)　2014/05

DOI： 10.7567/JJAP.53.058001 　

ISSN： 0021-4922

eISSN： 1347-4065
Nanocrystalline, Ultra-Degradation-Resistant Zirconia: Its Grain Boundary Nanostructure and Nanochemistry Peer-reviewed

Koji Matsui, Hidehiro Yoshida, Yuichi Ikuhara

SCIENTIFIC REPORTS　4　2014/04

DOI： 10.1038/srep04758 　

ISSN： 2045-2322
Atomic Structure of ZnO Sigma 13 [0001]/{13(4)over-bar0} Symmetric Tilt Grain Boundary Peer-reviewed

Ji-Young Roh, Yukio Sato, Yuichi Ikuhara

JOURNAL OF THE AMERICAN CERAMIC SOCIETY　97　(2)　617-621　2014/02

DOI： 10.1111/jace.12666 　

ISSN： 0002-7820

eISSN： 1551-2916
Fluorine in Shark Teeth: Its Direct Atomic-Resolution Imaging and Strengthening Function Peer-reviewed

Chunlin Chen, Zhongchang Wang, Mitsuhiro Saito, Tetsuya Tohei, Yoshiro Takano, Yuichi Ikuhara

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION　53　(6)　1543-1547　2014/02

DOI： 10.1002/anie.201307689 　

ISSN： 1433-7851

eISSN： 1521-3773
Enhancing Photocatalytic Activity of LaTiO2N by Removal of Surface Reconstruction Layer Peer-reviewed

Michinori Matsukawa, Ryo Ishikawa, Takashi Hisatomi, Yosuke Moriya, Naoya Shibata, Jun Kubota, Yuichi Ikuhara, Kazunari Domen

NANO LETTERS　14　(2)　1038-1041　2014/02

DOI： 10.1021/nl404688h 　

ISSN： 1530-6984

eISSN： 1530-6992
Core structure and dissociation energetics of basal edge dislocation in alpha-Al2O3: A combined atomistic simulation and transmission electron microscopy analysis Peer-reviewed

Kenji Tsuruta, Eita Tochigi, Yuki Kezuka, Kazuaki Takata, Naoya Shibata, Atsutomo Nakamura, Yuichi Ikuhara

ACTA MATERIALIA　65　76-84　2014/02

DOI： 10.1016/j.actamat.2013.11.035 　

ISSN： 1359-6454

eISSN： 1873-2453
Atomic-Scale Visualization of Polarization Pinning and Relaxation at Coherent BiFeO3/LaAlO3 Interfaces Peer-reviewed

Rong Huang, Hang-Chen Ding, Wen-I Liang, Yong-Chao Gao, Xiao-Dong Tang, Qing He, Chun-Gang Duan, Ziqiang Zhu, Junhao Chu, Craig A. J. Fisher, Tsukasa Hirayama, Yuichi Ikuhara, Ying-Hao Chu

ADVANCED FUNCTIONAL MATERIALS　24　(6)　793-799　2014/02

DOI： 10.1002/adfm.201301470 　

ISSN： 1616-301X

eISSN： 1616-3028
Atom-resolved STEM characterization for advanced materials

Ikuhara, Y.

Kobunshi　63　(9)　2014

ISSN： 0454-1138
Polymorphism of dislocation core structures at the atomic scale Peer-reviewed

Zhongchang Wang, Mitsuhiro Saito, Keith P. McKenna, Yuichi Ikuhara

NATURE COMMUNICATIONS　5　2014/01

DOI： 10.1038/ncomms4239 　

ISSN： 2041-1723
Role of grain boundaries in ZnO Peer-reviewed

Yukio Sato, Yuichi Ikuhara

OXIDE-BASED MATERIALS AND DEVICES V　8987　2014

DOI： 10.1117/12.2042752 　

ISSN： 0277-786X

eISSN： 1996-756X
Grain Boundary Segregation-Induced Phase Transformation and Grain Growth in Y2O3-Stabilized ZrO2 Polycrystals Peer-reviewed

Koji Matsui, Hidehiro Yoshida, Yuichi Ikuhara

ADVANCED CERAMICS AND NOVEL PROCESSING　616　8-13　2014

DOI： 10.4028/www.scientific.net/KEM.616.8 　

ISSN： 1013-9826
Direct Imaging of Pt Single Atoms Adsorbed on TiO2 (110) Surfaces Peer-reviewed

Teng-Yuan Chang, Yusuke Tanaka, Ryo Ishikawa, Kazuaki Toyoura, Katsuyuki Matsunaga, Yuichi Ikuhara, Naoya Shibata

NANO LETTERS　14　(1)　134-138　2014/01

DOI： 10.1021/nl403520c 　

ISSN： 1530-6984

eISSN： 1530-6992
Size-Dependent Staging and Phase Transition in LiFePO4/FePO4 Peer-reviewed

Changbao Zhu, Lin Gu, Liumin Suo, Jelena Popovic, Hong Li, Yuichi Ikuhara, Joachim Maier

ADVANCED FUNCTIONAL MATERIALS　24　(3)　312-318　2014/01

DOI： 10.1002/adfm.201301792 　

ISSN： 1616-301X

eISSN： 1616-3028
Segregation of Mn2+ Dopants as Interstitials in SrTiO3 Grain Boundaries Peer-reviewed

Hao Yang, Paul G. Kotula, Yukio Sato, Miaofang Chi, Yuichi Ikuhara, Nigel D. Browning

MATERIALS RESEARCH LETTERS　2　(1)　16-22　2014

DOI： 10.1080/21663831.2013.856815 　

ISSN： 2166-3831
Atomic Structure of Luminescent Centers in High-Efficiency Ce-doped w-AlN Single Crystal Peer-reviewed

Ryo Ishikawa, Andrew R. Lupini, Fumiyasu Oba, Scott D. Findlay, Naoya Shibata, Takashi Taniguchi, Kenji Watanabe, Hiroyuki Hayashi, Toshifumi Sakai, Isao Tanaka, Yuichi Ikuhara, Stephen J. Pennycook

SCIENTIFIC REPORTS　4　2014/01

DOI： 10.1038/srep03778 　

ISSN： 2045-2322
A New Layered Iron Arsenide Superconductor: (Ca,Pr)FeAs2 Peer-reviewed

Hiroyuki Yakita, Hiraku Ogino, Tomoyuki Okada, Akiyasu Yamamoto, Kohji Kishio, Tetsuya Tohei, Yuichi Ikuhara, Yoshito Gotoh, Hiroshi Fujihisa, Kunimitsu Kataoka, Hiroshi Eisaki, Jun-ichi Shimoyama

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY　136　(3)　846-849　2014/01

DOI： 10.1021/ja410845b 　

ISSN： 0002-7863

eISSN： 1520-5126
Characterization of Threading Edge Dislocation in 4H-SiC by X-ray Topography and Transmission Electron Microscopy Peer-reviewed

Yoshihiro Sugawara, Yong-Zhao Yao, Yukari Ishikawa, Katsunori Danno, Hiroshi Suzuki, Takeshi Bessho, Satoshi Yamaguchi, Koichi Nishikawa, Yuichi Ikuhara

SILICON CARBIDE AND RELATED MATERIALS 2013, PTS 1 AND 2　778-780　366-+　2014

DOI： 10.4028/www.scientific.net/MSF.778-780.366 　

ISSN： 0255-5476
A New Rechargeable Sodium Battery Utilizing Reversible Topotactic Oxygen Extraction/Insertion of CaFeOz (2.5 <= z <= 3) in an Organic Electrolyte Peer-reviewed

Mitsuhiro Hibino, Ryuji Harimoto, Yoshiyuki Ogasawara, Ryota Kido, Akira Sugahara, Tetsuichi Kudo, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara, Noritaka Mizuno

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY　136　(1)　488-494　2014/01

DOI： 10.1021/ja411365z 　

ISSN： 0002-7863

eISSN： 1520-5126
Domain boundary structures in lanthanum lithium titanates Peer-reviewed

Xiang Gao, Craig A. J. Fisher, Teiichi Kimura, Yumi H. Ikuhara, Akihide Kuwabara, Hiroki Moriwake, Hideki Oki, Takeshi Tojigamori, Keiichi Kohama, Yuichi Ikuhara

JOURNAL OF MATERIALS CHEMISTRY A　2　(3)　843-852　2014

DOI： 10.1039/c3ta13726k 　

ISSN： 2050-7488

eISSN： 2050-7496
Determination of Exact Positions of Individual Tungsten Atoms in Unisize Tungsten Oxide Clusters Supported on Carbon Substrate by HAADF-STEM Observation Peer-reviewed

Hisato Yasumatsu, Tetsuya Tohei, Yuichi Ikuhara

JOURNAL OF PHYSICAL CHEMISTRY C　118　(3)　1706-1711　2014/01

DOI： 10.1021/jp4083745 　

ISSN： 1932-7447
Multivariate Statistical Characterization of Charged and Uncharged Domain Walls in Multiferroic Hexagonal YMnO3 Single Crystal Visualized by a Spherical Aberration-Corrected STEM Peer-reviewed

Takao Matsumoto, Ryo Ishikawa, Tetsuya Tohei, Hideo Kimura, Qiwen Yao, Hongyang Zhao, Xiaolin Wang, Dapeng Chen, Zhenxiang Cheng, Naoya Shibata, Yuichi Ikuhara

NANO LETTERS　13　(10)　4594-4601　2013/10

DOI： 10.1021/nl402158c 　

ISSN： 1530-6984

eISSN： 1530-6992
Atomic-scale structure and electronic property of the La 2FeCrO6/SrTiO3 interface Peer-reviewed

Shuhui Lv, Mitsuhiro Saito, Zhongchang Wang, Chunlin Chen, Suvankar Chakraverty, Masashi Kawasaki, Yuichi Ikuhara

Journal of Applied Physics　114　(11)　2013/09/21

DOI： 10.1063/1.4821795 　

ISSN： 0021-8979
Thermal stability, morphology and electronic band gap of Zn(NCN) Peer-reviewed

Koji Morita, Gabriela Mera, Kaname Yoshida, Yuichi Ikuhara, Andreas Klein, Hans-Joachim Kleebe, Ralf Riedel

SOLID STATE SCIENCES　23　50-57　2013/09

DOI： 10.1016/j.solidstatesciences.2013.06.008 　

ISSN： 1293-2558
Effect of Oxygen Pressure on Electrical Properties of BiFe0.9Co0.1O3 Thin Films Prepared by Pulsed Laser Deposition Peer-reviewed

Hajime Hojo, Ko Onuma, Yuichi Ikuhara, Masaki Azuma

JAPANESE JOURNAL OF APPLIED PHYSICS　52　(9)　2013/09

DOI： 10.7567/JJAP.52.09KD09 　

ISSN： 0021-4922

eISSN： 1347-4065
Large Magnetoresistance in Magnetically Coupled SrRuO3-CoFe2O4 Self-Assembled Nanostructures Peer-reviewed

Heng-Jui Liu, Vu-Thanh Tra, Ying-Jiun Chen, Rong Huang, Chun-Gang Duan, Ying-Hui Hsieh, Hong-Ji Lin, Jiunn-Yuan Lin, Chien-Te Chen, Yuichi Ikuhara, Ying-Hao Chu

ADVANCED MATERIALS　25　(34)　4753-4759　2013/09

DOI： 10.1002/adma.201301461 　

ISSN： 0935-9648

eISSN： 1521-4095
Effect of local coordination of Mn on Mn-L2,3 edge electron energy loss spectrum Peer-reviewed

Shuji Nishida, Shunsuke Kobayashi, Akihito Kumamoto, Hidekazu Ikeno, Teruyasu Mizoguchi, Isao Tanaka, Yuichi Ikuhara, Takahisa Yamamoto

Journal of Applied Physics　114　(5)　2013/08/07

DOI： 10.1063/1.4817425 　

ISSN： 0021-8979
Direct Observation of Cationic Ordering in Double Perovskite Sr2FeReO6 Crystals Peer-reviewed

Si-Young Choi, Jong Bong Lim, Yuichi Ikuhara, Danilo Suvorov, Jae-Ho Jeon

MICROSCOPY AND MICROANALYSIS　19　25-28　2013/08

DOI： 10.1017/S1431927613012269 　

ISSN： 1431-9276

eISSN： 1435-8115
Local atomic structure of a near-sigma 5 tilt grain boundary in MgO Peer-reviewed

Mitsuhiro Saito, Zhongchang Wang, Susumu Tsukimoto, Yuichi Ikuhara

JOURNAL OF MATERIALS SCIENCE　48　(16)　5470-5474　2013/08

DOI： 10.1007/s10853-013-7340-7 　

ISSN： 0022-2461
Periodic nanowire array at the crystal interface Peer-reviewed

Atsutomo Nakamura, Teruyasu Mizoguchi, Katsuyuki Matsunaga, Takahisa Yamamoto, Naoya Shibata, Yuichi Ikuhara

ACS Nano　7　(7)　6297-6302　2013/07/23

DOI： 10.1021/nn4023334 　

ISSN： 1936-0851 1936-086X
Unusual 90°domain structure in (2/3)Bi(Zn1/2Ti 1/2)O3-(1/3)BiFeO3 epitaxial films with giant 22% tetragonal distortion Peer-reviewed

Shintaro Yasui, Keisuke Yazawa, Masaaki Matsushima, Tomoaki Yamada, Hitoshi Morioka, Hiroshi Uchida, Takashi Iijima, Lu You, Junling Wang, Takahisa Yamamoto, Yuichi Ikuhara, Hiroshi Funakubo

Applied Physics Letters　103　(4)　2013/07/22

DOI： 10.1063/1.4816420 　

ISSN： 0003-6951
Regulating Infrared Photoresponses in Reduced Graphene Oxide Phototransistors by Defect and Atomic Structure Control Peer-reviewed

Haixin Chang, Zhenhua Sun, Mitsuhiro Saito, Qinghong Yuan, Han Zhang, Jinhua Li, Zhongchang Wang, Takeshi Fujita, Feng Ding, Zijian Zheng, Feng Yan, Hongkai Wu, Mingwei Chen, Yuichi Ikuhara

ACS NANO　7　(7)　6310-6320　2013/07

DOI： 10.1021/nn4023679 　

ISSN： 1936-0851
Atomic-scale identification of individual lanthanide dopants in optical glass fiber Peer-reviewed

Teruyasu Mizoguchi, Scott D. Findlay, Atsunobu Masuno, Yoshihiro Saito, Koji Yamaguchi, Hiroyuki Inoue, Yuichi Ikuhara

ACS Nano　7　(6)　5058-5063　2013/06/25

DOI： 10.1021/nn400605z 　

ISSN： 1936-0851 1936-086X
Atomistic geometry and bonding characteristics at the Sr2FeTaO6/SrTiO3 interface Peer-reviewed

Shuhui Lv, Mitsuhiro Saito, Zhongchang Wang, Suvankar Chakraverty, Masashi Kawasaki, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　102　(22)　2013/06

DOI： 10.1063/1.4809536 　

ISSN： 0003-6951
Labyrinth-type domain structure of heteroepitaxial SrMnO2.5 film Peer-reviewed

Shunsuke Kobayashi, Yuichi Ikuhara, Takahisa Yamamoto

APPLIED PHYSICS LETTERS　102　(23)　2013/06

DOI： 10.1063/1.4811152 　

ISSN： 0003-6951
Direct atomic-scale confirmation of three-phase storage mechanism in Li4Ti5O12 anodes for room-temperature sodium-ion batteries Peer-reviewed

Yang Sun, Liang Zhao, Huilin Pan, Xia Lu, Lin Gu, Yong-Sheng Hu, Hong Li, Michel Armand, Yuichi Ikuhara, Liquan Chen, Xuejie Huang

NATURE COMMUNICATIONS　4　2013/05

DOI： 10.1038/ncomms2878 　

ISSN： 2041-1723
Atomic and electronic structure of La2CoMnO6 on SrTiO3 and LaAlO3 substrates from first principles Peer-reviewed

Shuhui Lv, Zhongchang Wang, Mitsuhiro Saito, Yuichi Ikuhara

JOURNAL OF APPLIED PHYSICS　113　(20)　2013/05

DOI： 10.1063/1.4807410 　

ISSN： 0021-8979
Lithium Atom and A-Site Vacancy Distributions in Lanthanum Lithium Titanate Peer-reviewed

Xiang Gao, Craig A. J. Fisher, Teiichi Kimura, Yumi H. Ikuhara, Hiroki Moriwake, Akihide Kuwabara, Hideki Oki, Takeshi Tojigamori, Rong Huang, Yuichi Ikuhara

CHEMISTRY OF MATERIALS　25　(9)　1607-1614　2013/05

DOI： 10.1021/cm3041357 　

ISSN： 0897-4756

eISSN： 1520-5002
Self-Limiting Chemical Vapor Deposition Growth of Monolayer Graphene from Ethanol Peer-reviewed

Pei Zhao, Akihito Kumamoto, Sungjin Kim, Xiao Chen, Bo Hou, Shohei Chiashi, Erik Einarsson, Yuichi Ikuhara, Shigeo Maruyama

JOURNAL OF PHYSICAL CHEMISTRY C　117　(20)　10755-10763　2013/05

DOI： 10.1021/jp400996s 　

ISSN： 1932-7447
Direct Atomic-Resolution Observation of Two Phases in the Li 1.2 Mn 0.567 Ni 0.166 Co 0.067 O 2 Cathode Material for Lithium-Ion Batteries Peer-reviewed

Haijun Yu, Ryo Ishikawa, Yeong-Gi So, Naoya Shibata, Tetsuichi Kudo, Haoshen Zhou, Yuichi Ikuhara

Angew. Chem.　125　(23)　6085　2013/04
Publisher: Wiley-Blackwell
DOI： 10.1002/ange.201301236 　
Grain-boundary structural transformation induced by geometry and chemistry Peer-reviewed

Yukio Sato, Ji-Young Roh, Yuichi Ikuhara

PHYSICAL REVIEW B　87　(14)　2013/04

DOI： 10.1103/PhysRevB.87.140101 　

ISSN： 1098-0121
Oxygen polarity and interfacial atomic arrangement in an MgxZn1-xO/C-MgO/sapphire heterostructure Peer-reviewed

Xiang He, Lin Gu, Sandong Guo, Zhanglong Liu, Richeng Yu, Zengxia Mei, Xiaolong Du, Banggui Liu, Yuichi Ikuhara, Xiaofeng Duan

JOURNAL OF PHYSICS D-APPLIED PHYSICS　46　(14)　2013/04

DOI： 10.1088/0022-3727/46/14/145303 　

ISSN： 0022-3727
Atomic structure, energetics, and chemical bonding of Y doped sigma 13 grain boundaries in -Al2O3 Peer-reviewed

Shinya Azuma, Naoya Shibata, Teruyasu Mizoguchi, Scott D. Findlay, Kaoru Nakamura, Yuichi Ikuhara

PHILOSOPHICAL MAGAZINE　93　(10-12)　1158-1171　2013/04

DOI： 10.1080/14786435.2012.733827 　

ISSN： 1478-6435
Cubic cesium hydrogen silicododecatungstate with anisotropic morphology and polyoxometalate vacancies exhibiting selective water sorption and cation-exchange properties Peer-reviewed

Yoshiyuki Ogasawara, Sayaka Uchida, Toshiaki Maruichi, Ryo Ishikawa, Naoya Shibata, Yuichi Ikuhara, Noritaka Mizuno

Chemistry of Materials　25　(6)　905-911　2013/03/26

DOI： 10.1021/cm3039448 　

ISSN： 0897-4756 1520-5002
Oxygen segregation at coherent grain boundaries of cubic boron nitride Peer-reviewed

Chunlin Chen, Shuhui Lv, Zhongchang Wang, Mitsuhiro Saito, Naoya Shibata, Takashi Taniguchi, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　102　(9)　2013/03

DOI： 10.1063/1.4795300 　

ISSN： 0003-6951
Functional Complex Point-Defect Structure in a Huge-Size-Mismatch System Peer-reviewed

Ryo Ishikawa, Naoya Shibata, Fumiyasu Oba, Takashi Taniguchi, Scott D. Findlay, Isao Tanaka, Yuichi Ikuhara

PHYSICAL REVIEW LETTERS　110　(6)　2013/02

DOI： 10.1103/PhysRevLett.110.065504 　

ISSN： 0031-9007
Effects of TiO2 support on the initial stage of pt nanoparticle growth Peer-reviewed

Teng-Yuan Chang, Yuichi Ikuhara, Naoya Shibata

Applied Physics Express　6　(2)　2013/02

DOI： 10.7567/APEX.6.025503 　

ISSN： 1882-0778 1882-0786
Real-Space Imaging of Light Elements by Annular Bright-Field Scanning Transmission Electron Microscopy

SHIBATA Naoya, FINDLAY Scott D., IKUHARA Yuichi

X-RAYS　55　(6)　362-368　2013
Publisher: The Crystallographic Society of Japan
DOI： 10.5940/jcrsj.55.362 　

ISSN： 0369-4585

More details Close

In this review, we report the basics and application of annular bright-field（ABF）imaging in scanning transmission electron microscopy（STEM）, which enables the direct imaging of light element atomic columns in crystals. In addition, we explain a recent technique for further enhancing the image contrast of light element columns, extending the idea of ABF STEM.
Antiphase inversion domains in lithium cobaltite thin films deposited on single-crystal sapphire substrates Peer-reviewed

Zheng, S.J., Fisher, C.A.J., Hitosugi, T., Kumatani, A., Shiraki, S., Ikuhara, Y.H., Kuwabara, A., Moriwake, H., Oki, H., Ikuhara, Y.

Acta Materialia　61　(20)　7671-7678　2013

DOI： 10.1016/j.actamat.2013.09.004 　

ISSN： 1359-6454
Microstructures and grain boundaries of cubic boron nitrides Peer-reviewed

Chunlin Chen, Rong Huang, Zhongchang Wang, Naoya Shibata, Takashi Taniguchi, Yuichi Ikuhara

Diamond and Related Materials　32　27-31　2013

DOI： 10.1016/j.diamond.2012.11.011 　

ISSN： 0925-9635
Spontaneous Structural Distortion and Quasi-One-Dimensional Quantum Confinement in a Single-Phase Compound Peer-reviewed

Zhongchang Wang, Lin Gu, Mitsuhiro Saito, Susumu Tsukimoto, Masaru Tsukada, Frank Lichtenberg, Yuichi Ikuhara, Johannes Georg Bednorz

ADVANCED MATERIALS　25　(2)　218-222　2013/01

DOI： 10.1002/adma.201203134 　

ISSN： 0935-9648
Ferromagnetic dislocations in antiferromagnetic NiO Peer-reviewed

Issei Sugiyama, Naoya Shibata, Zhongchang Wang, Shunsuke Kobayashi, Takahisa Yamamoto, Yuichi Ikuhara

Nature Nanotechnology　8　(4)　266-270　2013

DOI： 10.1038/nnano.2013.45 　

ISSN： 1748-3395 1748-3387
Scanning transmission electron microscopy and thermoelectric properties of Sr-doped misfit cobalt oxide Peer-reviewed

Takao Morimura, Yukio Sato, Yuichi Ikuhara, Takahiro Yamaguchi, Masayuki Hasaka

Japanese Journal of Applied Physics　52　(7)　2013/01

DOI： 10.7567/JJAP.52.071101 　

ISSN： 0021-4922 1347-4065
Direct Atomic-Resolution Observation of Two Phases in the Li1.2Mn0.567Ni0.166Co0.067O2 Cathode Material for Lithium-Ion Batteries Peer-reviewed

Haijun Yu, Ryo Ishikawa, Yeong-Gi So, Naoya Shibata, Tetsuichi Kudo, Haoshen Zhou, Yuichi Ikuhara

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION　52　(23)　5969-5973　2013

DOI： 10.1002/anie.201301236 　

ISSN： 1433-7851
First-Principles Calculations of Lithium-Ion Migration at a Coherent Grain Boundary in a Cathode Material, LiCoO2 Peer-reviewed

Hiroki Moriwake, Akihide Kuwabara, Craig A. J. Fisher, Rong Huang, Taro Hitosugi, Yumi H. Ikuhara, Hideki Oki, Yuichi Ikuhara

ADVANCED MATERIALS　25　(4)　618-622　2013/01

DOI： 10.1002/adma.201202805 　

ISSN： 0935-9648

eISSN： 1521-4095
Electron carrier-mediated room temperature ferromagnetism in anatase (ti,co) o 2

Tomoteru Fukumura, Yoshinori Yamada, Kazunori Ueno, Hongtao Yuan, Hidekazu Shimotani, Yoshihiro Iwasa, L. I.N. Gu, Susumu Tsukimoto, Yuichi Ikuhara, Masashi Kawasaki

SPIN　2　(4)　2012/12/01
Publisher: World Scientific Publishing Co. Pte Ltd
DOI： 10.1142/S2010324712300058 　

ISSN： 2010-3255 2010-3247
ZnO dense nanowire array on a film structure in a single crystal domain texture for optical and photoelectrochemical applications Peer-reviewed

Miao Zhong, Yukio Sato, Mario Kurniawan, Aleksandra Apostoluk, Bruno Masenelli, Etsuo Maeda, Yuichi Ikuhara, Jean-Jacques Delaunay

NANOTECHNOLOGY　23　(49)　2012/12

DOI： 10.1088/0957-4484/23/49/495602 　

ISSN： 0957-4484

eISSN： 1361-6528
New Insight into the Atomic Structure of Electrochemically Delithiated O3-Li(1-x)CoO2 (0 <= x <= 0.5) Nanoparticles Peer-reviewed

Xia Lu, Yang Sun, Zelang Jian, Xiaoqing He, Lin Gu, Yong-Sheng Hu, Hong Li, Zhaoxiang Wang, Wen Chen, Xiaofeng Duan, Liquan Chen, Joachim Maier, Susumu Tsukimoto, Yuichi Ikuhara

NANO LETTERS　12　(12)　6192-6197　2012/12

DOI： 10.1021/nl303036e 　

ISSN： 1530-6984
Domain formation in anatase TiO2 thin films on LaAlO3 substrates Peer-reviewed

Shijian Zheng, Craig A. J. Fisher, Takeharu Kato, Yuki Nagao, Hiromichi Ohta, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　101　(19)　2012/11

DOI： 10.1063/1.4766338 　

ISSN： 0003-6951

eISSN： 1077-3118
Direct observation of the cleavage plane of sapphire by in-situ indentation TEM Peer-reviewed

Takeo Sasaki, Naoya Shibata, Katsuyuki Matsunaga, Takahisa Yamamoto, Yuichi Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　120　(1407)　473-477　2012/11

DOI： 10.2109/jcersj2.120.473 　

ISSN： 1882-0743

eISSN： 1348-6535
Revealing Antiphase Boundaries and Defects at Atomic Resolution in NaLaMgWO6 Double Perovskites (vol 2, pg 51, 2012) Peer-reviewed

Shanming Li, Qingqing Gao, Jingbo Li, Xiaoqing He, Qinghua Zhang, Chao Li, Yang Shen, Lin Gu, Yuan Yao, Yanguo Wang, Richeng Yu, Xiaofeng Duan, Yuichi Ikuhara

MATERIALS EXPRESS　2　(3)　264-264　2012/09

DOI： 10.1166/mex.2012.1078 　

ISSN： 2158-5849
Gigantic Electrostrain in Duplex Structured Alkaline Niobates Peer-reviewed

Si-Young Choi, Soon-Jong Jeong, Dae-Su Lee, Min-Soo Kim, Jae-Shin Lee, Jeong Ho Cho, Byoung Ik Kim, Yuichi Ikuhara

CHEMISTRY OF MATERIALS　24　(17)　3363-3369　2012/09

DOI： 10.1021/cm301324h 　

ISSN： 0897-4756
Real-Space Distribution of Local WO4 Ordering in Negative Thermal Expansive ZrW2O8 Peer-reviewed

Yukio Sato, Yasuhisa Yamamura, Kazuya Saito, Yuichi Ikuhara

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY　134　(34)　13942-13945　2012/08

DOI： 10.1021/ja305456J 　

ISSN： 0002-7863
Differential phase-contrast microscopy at atomic resolution Peer-reviewed

Naoya Shibata, Scott D. Findlay, Yuji Kohno, Hidetaka Sawada, Yukihito Kondo, Yuichi Ikuhara

NATURE PHYSICS　8　(8)　611-615　2012/08

DOI： 10.1038/NPHYS2337 　

ISSN： 1745-2473
Transmission Electron Microscopy Analysis of a Threading Dislocation with c+a Burgers Vector in 4H-SiC Peer-reviewed

Yoshihiro Sugawara, Michio Nakamori, Yong-Zhao Yao, Yukari Ishikawa, Katsunori Danno, Hiroshi Suzuki, Takeshi Bessho, Satoshi Yamaguchi, Koichi Nishikawa, Yuichi Ikuhara

APPLIED PHYSICS EXPRESS　5　(8)　2012/08

DOI： 10.1143/APEX.5.081301 　

ISSN： 1882-0778

eISSN： 1882-0786
Structural and electronic impact of SrTiO3 substrate on TiO2 thin films Peer-reviewed

Zhongchang Wang, Rong Sun, Chunlin Chen, Mitsuhiro Saito, Susumu Tsukimoto, Yuichi Ikuhara

JOURNAL OF MATERIALS SCIENCE　47　(13)　5148-5157　2012/07

DOI： 10.1007/s10853-012-6392-4 　

ISSN： 0022-2461
Nanowire of hexagonal gallium oxynitride: Direct observation of its stacking disorder and its long nanowire growth Peer-reviewed

Yuji Masubuchi, Ryohei Yamaoka, Tetsuya Tohei, Teruyasu Mizoguchi, Yuichi Ikuhara, Shinichi Kikkawa

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY　32　(9)　1989-1993　2012/07

DOI： 10.1016/j.jeurceramsoc.2011.10.038 　

ISSN： 0955-2219

eISSN： 1873-619X
Terraces at ohmic contact in SiC electronics: Structure and electronic states Peer-reviewed

Zhongchang Wang, Mitsuhiro Saito, Susumu Tsukimoto, Yuichi Ikuhara

JOURNAL OF APPLIED PHYSICS　111　(11)　2012/06

DOI： 10.1063/1.4729074 　

ISSN： 0021-8979

eISSN： 1089-7550
Lithium Storage in Li4Ti5O12 Spinel: The Full Static Picture from Electron Microscopy Peer-reviewed

Xia Lu, Liang Zhao, Xiaoqing He, Ruijuan Xiao, Lin Gu, Yong-Sheng Hu, Hong Li, Zhaoxiang Wang, Xiaofeng Duan, Liquan Chen, Joachim Maier, Yuichi Ikuhara

ADVANCED MATERIALS　24　(24)　3233-3238　2012/06

DOI： 10.1002/adma.201200450 　

ISSN： 0935-9648

eISSN： 1521-4095
Flower-like surface modification of titania materials by lithium hydroxide solution Peer-reviewed

George Hasegawa, Kazuyoshi Kanamori, Yoshihiro Sugawara, Yuichi Ikuhara, Kazuki Nakanishi

JOURNAL OF COLLOID AND INTERFACE SCIENCE　374　291-296　2012/05

DOI： 10.1016/j.jcis.2012.02.002 　

ISSN： 0021-9797
Rutile-TiO2 Nanocoating for a High-Rate Li4Ti5O12 Anode of a Lithium-Ion Battery Peer-reviewed

Yong-Qing Wang, Lin Guo, Yu-Guo Guo, Hong Li, Xiao-Qing He, Susumu Tsukimoto, Yuichi Ikuhara, Li-Jun Wan

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY　134　(18)　7874-7879　2012/05

DOI： 10.1021/ja301266w 　

ISSN： 0002-7863
Low-Temperature Superplasticity in Nanocrystalline Tetragonal Zirconia Polycrystal (TZP) Peer-reviewed

Hidehiro Yoshida, Koji Matsui, Yuichi Ikuhara

JOURNAL OF THE AMERICAN CERAMIC SOCIETY　95　(5)　1701-1708　2012/05

DOI： 10.1111/j.1551-2916.2012.05150.x 　

ISSN： 0002-7820
Simultaneous visualization of oxygen vacancies and the accompanying cation shifts in a perovskite oxide by combining annular imaging techniques Peer-reviewed

Shunsuke Kobayashi, Scott D. Findlay, Naoya Shibata, Teruyasu Mizoguchi, Yukio Sato, Eiji Okunishi, Yuichi Ikuhara, Takahisa Yamamoto

APPLIED PHYSICS LETTERS　100　(19)　2012/05

DOI： 10.1063/1.4714920 　

ISSN： 0003-6951

eISSN： 1077-3118
Distinct Configurations of Antisite Defects in Ordered Metal Phosphates: Comparison between LiMnPO4 and LiFePO4 Peer-reviewed

Sung-Yoon Chung, Si-Young Choi, Seongsu Lee, Yuichi Ikuhara

PHYSICAL REVIEW LETTERS　108　(19)　2012/05

DOI： 10.1103/PhysRevLett.108.195501 　

ISSN： 0031-9007
Evolution of nanodomains under DC electrical bias in Pb(Mg1/3Nb2/3) O-3-PbTiO3: An In-situ transmission electron microscopy study Peer-reviewed

Yukio Sato, Tsukasa Hirayama, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　100　(17)　2012/04

DOI： 10.1063/1.4705418 　

ISSN： 0003-6951
Phase transitions in LiCoO2 thin films prepared by pulsed laser deposition Peer-reviewed

Rong Huang, Taro Hitosugi, Craig A. J. Fisher, Yumi H. Ikuhara, Hiroki Moriwake, Hideki Oki, Yuichi Ikuhara

MATERIALS CHEMISTRY AND PHYSICS　133　(2-3)　1101-1107　2012/04

DOI： 10.1016/j.matchemphys.2012.02.022 　

ISSN： 0254-0584
Dynamic observations of dislocation behavior in SrTiO3 by in situ nanoindentation in a transmission electron microscope Peer-reviewed

Shun Kondo, Naoya Shibata, Tasuku Mitsuma, Eita Tochigi, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　100　(18)　2012/04

DOI： 10.1063/1.4710558 　

ISSN： 0003-6951
Revealing Antiphase Boundaries and Defects at Atomic Resolution in NaLaMgWO6 Double Perovskites Peer-reviewed

Shanming Li, Qingqing Gao, Jingbo Li, Xiaoqing He, Qinghua Zhang, Chao Li, Yang Shen, Lin Gu, Yuan Yao, Yanguo Wang, Richeng Yu, Xiaofeng Duan, Yuichi Ikuhara

MATERIALS EXPRESS　2　(1)　51-56　2012/03

DOI： 10.1166/mex.2012.1054 　

ISSN： 2158-5849
STEM characterization for lithium-ion battery cathode materials Peer-reviewed

Rong Huang, Yuichi Ikuhara

CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE　16　(1)　31-38　2012/02

DOI： 10.1016/j.cossms.2011.08.002 　

ISSN： 1359-0286
Unusually Large Enhancement of Thermopower in an Electric Field Induced Two-Dimensional Electron Gas Peer-reviewed

Hiromichi Ohta, Taku Mizuno, Shijian Zheng, Takeharu Kato, Yuichi Ikuhara, Katsumi Abe, Hideya Kumomi, Kenji Nomura, Hideo Hosono

ADVANCED MATERIALS　24　(6)　740-+　2012/02

DOI： 10.1002/adma.201103809 　

ISSN： 0935-9648

eISSN： 1521-4095
A High-Coincidence Twin Boundary in Lithium Battery Material LiCoO2 Peer-reviewed

Craig A. J. Fisher, Rong Huang, Taro Hitosugi, Hiroki Moriwake, Akihide Kuwabara, Yumi H. Ikuhara, Hideki Oki, Yuichi Ikuhara

NANOSCIENCE AND NANOTECHNOLOGY LETTERS　4　(2)　165-168　2012/02

DOI： 10.1166/nnl.2012.1301 　

ISSN： 1941-4900

eISSN： 1941-4919
Structure of screw dislocations in a (0 0 0 1)/[0 0 0 1] low-angle twist grain boundary of alumina (α-Al ₂O ₃) Peer-reviewed

Tochigi, E., Kezuka, Y., Shibata, N., Nakamura, A., Ikuhara, Y.

Acta Materialia　60　(3)　1293-1299　2012

DOI： 10.1016/j.actamat.2011.11.027 　

ISSN： 1359-6454
First principles calculation of dopant solution energy in HfO ₂ polymorphs Peer-reviewed

Saitoh, M., Mizoguchi, T., Tohei, T., Ikuhara, Y.

Journal of Applied Physics　112　(8)　2012

DOI： 10.1063/1.4755797 　

ISSN： 0021-8979
Atomic structure of a σ3 [110]/(111) grain boundary in CeO ₂ Peer-reviewed

Feng, B., Hojo, H., Mizoguchi, T., Ohta, H., Findlay, S.D., Sato, Y., Shibata, N., Yamamoto, T., Ikuhara, Y.

Applied Physics Letters　100　(7)　2012

DOI： 10.1063/1.3682310 　

ISSN： 0003-6951
High-resolution observation of basal-plane C-core edge dislocations in 4H-SiC crystal by transmission electron microscopy Peer-reviewed

Hirofumi Matsuhata, Takeharu Kato, Susumu Tsukimoto, Yuichi Ikuhara

PHILOSOPHICAL MAGAZINE　92　(31)　3780-3788　2012

DOI： 10.1080/14786435.2012.687839 　

ISSN： 1478-6435
High Crystallinity CuScO2 Delafossite Films Exhibiting Ultraviolet Photoluminescence Grown by Vapor-Liquid-Solid Tri-phase Epitaxy Peer-reviewed

Yuya Matsubara, Takayuki Makino, Hiroki Hiraga, Chunlin Chen, Susumu Tsukimoto, Kazunori Ueno, Yusuke Kozuka, Yuichi Ikuhara, Masashi Kawasaki

APPLIED PHYSICS EXPRESS　5　(1)　2012/01

DOI： 10.1143/APEX.5.011201 　

ISSN： 1882-0778
Highly ordered staging structural interface between LiFePO4 and FePO4 Peer-reviewed

Liumin Suo, Wenze Han, Xia Lu, Lin Gu, Yong-Sheng Hu, Hong Li, Dongfeng Chen, Liquan Chen, Susumu Tsukimoto, Yuichi Ikuhara

PHYSICAL CHEMISTRY CHEMICAL PHYSICS　14　(16)　5363-5367　2012

DOI： 10.1039/c2cp40610a 　

ISSN： 1463-9076

eISSN： 1463-9084
The influence of charge ordering on the phase stability of spinel LiNi2O4 Peer-reviewed

Akihide Kuwabara, Craig A. J. Fisher, Yumi H. Ikuhara, Hiroki Moriwake, Hideki Oki, Yuichi Ikuhara

RSC ADVANCES　2　(33)　12940-12948　2012

DOI： 10.1039/c2ra21043f 　

ISSN： 2046-2069
Microstructural Observation of LiNi0.8Co0.15Al0.05O2 after Charge and Discharge by Scanning Transmission Electron Microscopy Peer-reviewed

Yoshinari Makimura, Shijian Zheng, Yuichi Ikuhara, Yoshio Ukyo

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　159　(7)　A1070-A1073　2012

DOI： 10.1149/2.073207jes 　

ISSN： 0013-4651
First principles pseudopotential calculation of electron energy loss near edge structures of lattice imperfections Peer-reviewed

Teruyasu Mizoguchi, Katsuyuki Matsunaga, Eita Tochigi, Yuichi Ikuhara

MICRON　43　(1)　37-42　2012/01

DOI： 10.1016/j.micron.2011.07.005 　

ISSN： 0968-4328
Atom-resolved imaging of ordered defect superstructures at individual grain boundaries Peer-reviewed

Zhongchang Wang, Mitsuhiro Saito, Keith P. McKenna, Lin Gu, Susumu Tsukimoto, Alexander L. Shluger, Yuichi Ikuhara

NATURE　479　(7373)　380-383　2011/11

DOI： 10.1038/nature10593 　

ISSN： 0028-0836
Heterointerfaces: atomic structures, electronic states, and related properties Peer-reviewed

Zhongchang Wang, Mitsuhiro Saito, Susumu Tsukimoto, Yuichi Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　119　(1395)　783-793　2011/11

DOI： 10.2109/jcersj2.119.783 　

ISSN： 1882-0743

eISSN： 1348-6535
Zr segregation and associated Al vacancies in alumina grain boundaries Peer-reviewed

James P. Buban, Teruyasu Mizoguchi, Naoya Shibata, Eiji Abe, Takahisa Yamamoto, Yuichi Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　119　(1395)　840-844　2011/11

DOI： 10.2109/jcersj2.119.840 　

ISSN： 1882-0743

eISSN： 1348-6535
TEM analysis of dislocation structures formed in the Cr-doped grain boundary of alumina Peer-reviewed

Yuki Kezuka, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　119　(1395)　817-821　2011/11

DOI： 10.2109/jcersj2.119.817 　

ISSN： 1882-0743

eISSN： 1348-6535
Characterization and atomic modeling of an asymmetric grain boundary Peer-reviewed

Hak-Sung Lee, Teruyasu Mizoguchi, Takahisa Yamamoto, Suk-Joong L. Kang, Yuichi Ikuhara

PHYSICAL REVIEW B　84　(19)　2011/11

DOI： 10.1103/PhysRevB.84.195319 　

ISSN： 1098-0121
Growth of Ruddlesden-Popper type faults in Sr-excess SrTiO₃ homoepitaxial thin films by pulsed laser deposition Peer-reviewed

Tokuda, Y., Kobayashi, S., Ohnishi, T., Mizoguchi, T., Shibata, N., Ikuhara, Y., Yamamoto, T.

Applied Physics Letters　99　(17)　2011/10

DOI： 10.1063/1.3656340 　

ISSN： 0003-6951
Real-Time Direct Observations of Polarization Reversal in a Piezoelectric Crystal: Pb(Mg1/3Nb2/3)O-3-PbTiO3 Studied via In Situ Electrical Biasing Transmission Electron Microscopy Peer-reviewed

Yukio Sato, Tsukasa Hirayama, Yuichi Ikuhara

PHYSICAL REVIEW LETTERS　107　(18)　2011/10

DOI： 10.1103/PhysRevLett.107.187601 　

ISSN： 0031-9007
Grain boundary character dependence of oxygen grain boundary diffusion in alpha-Al2O3 bicrystals Peer-reviewed

Tsubasa Nakagawa, Hitoshi Nishimura, Isao Sakaguchi, Naoya Shibata, Katsuyuki Matsunaga, Takahisa Yamamoto, Yuichi Ikuhara

SCRIPTA MATERIALIA　65　(6)　544-547　2011/09

DOI： 10.1016/j.scriptamat.2011.06.024 　

ISSN： 1359-6462
Electric field thermopower modulation analysis of an interfacial conducting layer formed between Y2O3 and rutile TiO2 Peer-reviewed

Taku Mizuno, Yuki Nagao, Akira Yoshikawa, Kunihito Koumoto, Takeharu Kato, Yuichi Ikuhara, Hiromichi Ohta

JOURNAL OF APPLIED PHYSICS　110　(6)　2011/09

DOI： 10.1063/1.3633217 　

ISSN： 0021-8979

eISSN： 1089-7550
Ferrimagnetism and spontaneous ordering of transition metals in double perovskite La₂CrFeO₆ films Peer-reviewed

Chakraverty, S., Ohtomo, A., Okuyama, D., Saito, M., Okude, M., Kumai, R., Arima, T., Tokura, Y., Tsukimoto, S., Ikuhara, Y., Kawasaki, M.

Physical Review B - Condensed Matter and Materials Physics　84　(6)　2011/08/26

DOI： 10.1103/PhysRevB.84.064436 　

ISSN： 1098-0121 1550-235X
Grain boundary atomic structures and light-element visualization in ceramics: combination of Cs-corrected scanning transmission electron microscopy and first-principles calculations Peer-reviewed

Yuichi Ikuhara

JOURNAL OF ELECTRON MICROSCOPY　60　S173-S188　2011/08

DOI： 10.1093/jmicro/dfr049 　

ISSN： 0022-0744
A new iron pnictide oxide (Fe2As2)(Ca-5(Mg, Ti)(4)O-y) and a new phase in the Fe-As-Ca-Mg-Ti-O system Peer-reviewed

Hiraku Ogino, Yasuaki Shimizu, Naoto Kawaguchi, Kohji Kishio, Jun-ichi Shimoyama, Tetsuya Tohei, Yuichi Ikuhara

SUPERCONDUCTOR SCIENCE & TECHNOLOGY　24　(8)　2011/08

DOI： 10.1088/0953-2048/24/8/085020 　

ISSN： 0953-2048
First-principles study of grain boundary sliding in alpha-Al2O3 (vol 75, 184109, 2007) Peer-reviewed

Kaoru Nakamura, Teruyasu Mizoguchi, Naoya Shibata, Katsuyuki Matsunaga, Takahisa Yamamoto, Yuichi Ikuhara

PHYSICAL REVIEW B　84　(5)　2011/08

DOI： 10.1103/PhysRevB.84.059903 　

ISSN： 1098-0121
Strontium vacancy clustering in Ti-excess SrTiO₃ thin film Peer-reviewed

Tokuda, Y., Kobayashi, S., Ohnishi, T., Mizoguchi, T., Shibata, N., Ikuhara, Y., Yamamoto, T.

Applied Physics Letters　99　(3)　2011/07

DOI： 10.1063/1.3616136 　

ISSN： 0003-6951
Formation of a Cr3+-rich luminescent thin phase along a grain boundary of alpha-Al2O3 Peer-reviewed

Yuki Kezuka, Eita Tochigi, Naoya Shibata, Chiwon Moon, Shingo Kanehira, Kazuyuki Hirao, Yuichi Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　119　(1391)　620-622　2011/07

DOI： 10.2109/jcersj2.119.620 　

ISSN： 1882-0743

eISSN： 1348-6535
Mass transfer through a single grain boundary in alumina bicrystals under oxygen potential gradients Peer-reviewed

Tsuneaki Matsudaira, Satoshi Kitaoka, Naoya Shibata, Tsubasa Nakagawa, Yuichi Ikuhara

JOURNAL OF MATERIALS SCIENCE　46　(12)　4407-4412　2011/06

DOI： 10.1007/s10853-010-5017-z 　

ISSN： 0022-2461
Controlling Interface Intermixing and Properties of SrTiO3-Based Superlattices Peer-reviewed

Teruyasu Mizoguchi, Hiromichi Ohta, Hak-Sung Lee, Nobuaki Takahashi, Yuichi Ikuhara

ADVANCED FUNCTIONAL MATERIALS　21　(12)　2258-2263　2011/06

DOI： 10.1002/adfm.201100230 　

ISSN： 1616-301X

eISSN： 1616-3028
TEM observation of liquid-phase bonded aluminum-silicon/aluminum nitride hetero interface Peer-reviewed

Christine Marie Montesa, Naoya Shibata, Tetsuya Tohei, Yuichi Ikuhara

JOURNAL OF MATERIALS SCIENCE　46　(12)　4392-4396　2011/06

DOI： 10.1007/s10853-010-5023-1 　

ISSN： 0022-2461
Preface to the special issue on intergranular and interphase boundaries in materials Peer-reviewed

Yuichi Ikuhara, Masanori Kohyama

JOURNAL OF MATERIALS SCIENCE　46　(12)　4093-4094　2011/06

DOI： 10.1007/s10853-011-5453-4 　

ISSN： 0022-2461
Direct Observation of Lithium Staging in Partially Delithiated LiFePO4 at Atomic Resolution Peer-reviewed

Lin Gu, Changbao Zhu, Hong Li, Yan Yu, Chilin Li, Susumu Tsukimoto, Joachim Maier, Yuichi Ikuhara

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY　133　(13)　4661-4663　2011/04

DOI： 10.1021/ja109412x 　

ISSN： 0002-7863
Atomic structure and strain field of threading dislocations in CeO2 thin films on yttria-stabilized ZrO2 Peer-reviewed

Hajime Hojo, Eita Tochigi, Teruyasu Mizoguchi, Hiromichi Ohta, Naoya Shibata, Bin Feng, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　98　(15)　2011/04

DOI： 10.1063/1.3575566 　

ISSN： 0003-6951

eISSN： 1077-3118
Atomic-scale Ti3SiC2 bilayers embedded in SiC: Formation of point Fermi surface Peer-reviewed

Zhongchang Wang, Susumu Tsukimoto, Rong Sun, Mitsuhiro Saito, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　98　(10)　2011/03

DOI： 10.1063/1.3560505 　

ISSN： 0003-6951
Direct Imaging of Lithium Ions Using Aberration-Corrected Annular-Bright-Field Scanning Transmission Electron Microscopy and Associated Contrast Mechanisms Peer-reviewed

Xiaoqing He, Lin Gu, Changbao Zhu, Yan Yu, Chilin Li, Yong-Sheng Hu, Hong Li, Susumu Tsukimoto, Joachim Maier, Yuichi Ikuhara, Xiaofeng Duan

MATERIALS EXPRESS　1　(1)　43-50　2011/03

DOI： 10.1166/mex.2011.1006 　

ISSN： 2158-5849
Cation diffusion along basal dislocations in sapphire Peer-reviewed

Tsubasa Nakagawa, Atsutomo Nakamura, Isao Sakaguchi, Naoya Shibata, Teruyasu Mizoguchi, Takahisa Yamamoto, Hajime Haneda, Naoki Ohashi, Yuichi Ikuhara

ACTA MATERIALIA　59　(3)　1105-1111　2011/02

DOI： 10.1016/j.actamat.2010.10.041 　

ISSN： 1359-6454

eISSN： 1873-2453
Direct bonded aluminum on aluminum nitride substrates via a transient liquid phase and its application

Yoshirou Kuromitsu, Yoshiyuki Nagatomo, Hiroshi Tonomura, Kazuhiro Akiyama, Christine Marie Montesa, Naoya Shibata, Yuichi Ikuhara

2010 6th International Conference on Integrated Power Electronics Systems, CIPS 2010　2011
Electrically induced ferromagnetism at room temperature in cobalt-doped titanium dioxide Peer-reviewed

Yamada, Y., Ueno, K., Fukumura, T., Yuan, H.T., Shimotani, H., Iwasa, Y., Gu, L., Tsukimoto, S., Ikuhara, Y., Kawasaki, M.

Science　332　(6033)　1065-1067　2011

DOI： 10.1126/science.1202152 　

ISSN： 0036-8075 1095-9203
The effect of vacancies on the annular dark field image contrast of grain boundaries: A SrTiO ₃ case study Peer-reviewed

Lee, H.-S., Findlay, S.D., Mizoguchi, T., Ikuhara, Y.

Ultramicroscopy　111　(11)　1531-1539　2011

DOI： 10.1016/j.ultramic.2011.08.013 　

ISSN： 0304-3991 1879-2723
Scanning transmission electron microscopy imaging dynamics at low accelerating voltages Peer-reviewed

Lugg, N.R., Findlay, S.D., Shibata, N., Mizoguchi, T., D{'}Alfonso, A.J., Allen, L.J., Ikuhara, Y.

Ultramicroscopy　111　(8)　999-1013　2011

DOI： 10.1016/j.ultramic.2011.02.009 　

ISSN： 0304-3991 1879-2723
Erratum: First-principles sliding simulation of Al-terminated Σ13 pyramidal twin grain boundary in α-Al₂O₃ (Philosophical Magazine Letters (2010) 90:3 (159-172)) Peer-reviewed

Nakamura, K., Mizoguchi, T., Shibata, N., Matsunaga, K., Yamamoto, T., Ikuhara, Y.

Philosophical Magazine Letters　91　(9)　561-562　2011

DOI： 10.1080/09500839.2011.598138 　

ISSN： 0950-0839 1362-3036
Defect energetics in SrTiO₃ symmetric tilt grain boundaries Peer-reviewed

Lee, H.-S., Mizoguchi, T., Mistui, J., Yamamoto, T., Kang, S.-J.L., Ikuhara, Y.

Physical Review B - Condensed Matter and Materials Physics　83　(10)　2011

DOI： 10.1103/PhysRevB.83.104110 　

ISSN： 1098-0121 1550-235X
Oxygen-Vacancy Ordering at Surfaces of Lithium Manganese(III,IV) Oxide Spinel Nanoparticles Peer-reviewed

Rong Huang, Yumi H. Ikuhara, Teruyasu Mizoguchi, Scott D. Findlay, Akihide Kuwabara, Craig A. J. Fisher, Hiroki Moriwake, Hideki Oki, Tsukasa Hirayama, Yuichi Ikuhara

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION　50　(13)　3053-3057　2011

DOI： 10.1002/anie.201004638 　

ISSN： 1433-7851
Real-time direct observation of Li in LiCoO2 cathode material Peer-reviewed

Rong Huang, Taro Hitosugi, Scott D. Findlay, Craig A. J. Fisher, Yumi H. Ikuhara, Hiroki Moriwake, Hideki Oki, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　98　(5)　2011/01

DOI： 10.1063/1.3551538 　

ISSN： 0003-6951
Microstructural Changes in LiNi0.8Co0.15Al0.05O2 Positive Electrode Material during the First Cycle Peer-reviewed

Shijian Zheng, Rong Huang, Yoshinari Makimura, Yoshio Ukyo, Craig A. J. Fisher, Tsukasa Hirayama, Yuichi Ikuhara

JOURNAL OF THE ELECTROCHEMICAL SOCIETY　158　(4)　A357-A362　2011

DOI： 10.1149/1.3544843 　

ISSN： 0013-4651
Grain-Boundary Segregation and Phase-Separation Mechanism in Yttria-Stabilized Tetragonal Zirconia Polycrystal Peer-reviewed

Koji Matsui, Hidehiro Yoshida, Yuichi Ikuhara

ADVANCED ENGINEERING CERAMICS AND COMPOSITES　484　82-+　2011

DOI： 10.4028/www.scientific.net/KEM.484.82 　

ISSN： 1013-9826
Morphology change from nanocrack into periodic pore array formed by femtosecond laser pulses Peer-reviewed

Chiwon Moon, Shingo Kanehira, Kiyotaka Miura, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara, Kazuyuki Hirao

JOURNAL OF APPLIED PHYSICS　109　(1)　2011/01

DOI： 10.1063/1.3527899 　

ISSN： 0021-8979

eISSN： 1089-7550
First-principles sliding simulation of Al-terminated Sigma 13 pyramidal twin grain boundary in alpha-Al2O3 (vol 90, pg 159, 2010) Peer-reviewed

Kaoru Nakamura, Teruyasu Mizoguchi, Naoya Shibata, Katsuyuki Matsunaga, Takahisa Yamamoto, Yuichi Ikuhara

PHILOSOPHICAL MAGAZINE LETTERS　91　(9)　561-562　2011

DOI： 10.1080/09500839.2011.598138 　

ISSN： 0950-0839
Quantitative analyses of oxidation states for cubic SrMnO₃ and orthorhombic SrMnO_2.5 with electron energy loss spectroscopy Peer-reviewed

Kobayashi, S., Tokuda, Y., Mizoguchi, T., Shibata, N., Sato, Y., Ikuhara, Y., Yamamoto, T.

Journal of Applied Physics　108　(12)　2010/12

DOI： 10.1063/1.3520655 　

ISSN： 0021-8979
Atomic-scale structure and electronic property of the LaAlO3/TiO2 interface Peer-reviewed

Zhongchang Wang, Wen Zeng, Lin Gu, Mitsuhiro Saito, Susumu Tsukimoto, Yuichi Ikuhara

JOURNAL OF APPLIED PHYSICS　108　(11)　2010/12

DOI： 10.1063/1.3516496 　

ISSN： 0021-8979
New area detector for atomic-resolution scanning transmission electron microscopy Peer-reviewed

Naoya Shibata, Yuji Kohno, Scott D. Findlay, Hidetaka Sawada, Yukihito Kondo, Yuichi Ikuhara

JOURNAL OF ELECTRON MICROSCOPY　59　(6)　473-479　2010/12

DOI： 10.1093/jmicro/dfq014 　

ISSN： 0022-0744
Atomic Structure of a CeO2 Grain Boundary: The Role of Oxygen Vacancies Peer-reviewed

Hajime Hojo, Teruyasu Mizoguchi, Hiromichi Ohta, Scott D. Findlay, Naoya Shibata, Takahisa Yamamoto, Yuichi Ikuhara

NANO LETTERS　10　(11)　4668-4672　2010/11

DOI： 10.1021/nl1029336 　

ISSN： 1530-6984

eISSN： 1530-6992
Electric field modulation of thermopower for transparent amorphous oxide thin film transistors Peer-reviewed

Hirotaka Koide, Yuki Nagao, Kunihito Koumoto, Yuka Takasaki, Tomonari Umemura, Takeharu Kato, Yuichi Ikuhara, Hiromichi Ohta

APPLIED PHYSICS LETTERS　97　(18)　2010/11

DOI： 10.1063/1.3512870 　

ISSN： 0003-6951

eISSN： 1077-3118
Dimensionality-driven insulator-metal transition in A-site excess non-stoichiometric perovskites Peer-reviewed

Zhongchang Wang, Masaki Okude, Mitsuhiro Saito, Susumu Tsukimoto, Akira Ohtomo, Masaru Tsukada, Masashi Kawasaki, Yuichi Ikuhara

NATURE COMMUNICATIONS　1　2010/11

DOI： 10.1038/ncomms1111 　

ISSN： 2041-1723
Field-induced water electrolysis switches an oxide semiconductor from an insulator to a metal Peer-reviewed

Hiromichi Ohta, Yukio Sato, Takeharu Kato, SungWng Kim, Kenji Nomura, Yuichi Ikuhara, Hideo Hosono

NATURE COMMUNICATIONS　1　2010/11

DOI： 10.1038/ncomms1112 　

ISSN： 2041-1723
Cr diffusion in alpha-Al2O3: Secondary ion mass spectroscopy and first-principles study Peer-reviewed

Nobuaki Takahashi, Teruyasu Mizoguchi, Tsubasa Nakagawa, Tetsuya Tohei, Isao Sakaguchi, Akihide Kuwabara, Naoya Shibata, Takahisa Yamamoto, Naoki Ohashi, Yuichi Ikuhara

PHYSICAL REVIEW B　82　(17)　2010/11

DOI： 10.1103/PhysRevB.82.174302 　

ISSN： 1098-0121

eISSN： 1550-235X
Direct bandgap measurements in a three-dimensionally macroporous silicon 9R polytype using monochromated transmission electron microscope Peer-reviewed

Lin Gu, Yan Yu, Wilfried Sigle, Noritaka Usami, Susumu Tsukimoto, Joachim Maier, Yuichi Ikuhara, Peter A. van Aken

APPLIED PHYSICS LETTERS　97　(21)　2010/11

DOI： 10.1063/1.3518703 　

ISSN： 0003-6951
A new homologous series of iron pnictide oxide superconductors (Fe2As2)(Can+2(Al, Ti)(n)O-y) (n=2, 3, 4) Peer-reviewed

Hiraku Ogino, Kenji Machida, Akiyasu Yamamoto, Kohji Kishio, Jun-ichi Shimoyama, Tetsuya Tohei, Yuichi Ikuhara

SUPERCONDUCTOR SCIENCE & TECHNOLOGY　23　(11)　2010/11

DOI： 10.1088/0953-2048/23/11/115005 　

ISSN： 0953-2048
Experimental characterization of the electronic structure of anatase TiO2: Thermopower modulation Peer-reviewed

Yuki Nagao, Akira Yoshikawa, Kunihito Koumoto, Takeharu Kato, Yuichi Ikuhara, Hiromichi Ohta

APPLIED PHYSICS LETTERS　97　(17)　2010/10

DOI： 10.1063/1.3507898 　

ISSN： 0003-6951

eISSN： 1077-3118
Origins of Hole Doping and Relevant Optoelectronic Properties of Wide Gap p-Type Semiconductor, LaCuOSe Peer-reviewed

Hidenori Hiramatsu, Toshio Kamiya, Tetsuya Tohei, Eiji Ikenaga, Teruyasu Mizoguchi, Yuichi Ikuhara, Keisuke Kobayashi, Hideo Hosono

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY　132　(42)　15060-15067　2010/10

DOI： 10.1021/ja107042r 　

ISSN： 0002-7863
Application of coincidence of reciprocal lattice point model to metal/sapphire hetero interfaces Peer-reviewed

Christine Marie Montesa, Naoya Shibata, Tetsuya Tohei, Kazuhiro Akiyama, Yoshirou Kuromitsu, Yuichi Ikuhara

MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS　173　(1-3)　234-238　2010/10

DOI： 10.1016/j.mseb.2009.12.023 　

ISSN： 0921-5107
Interface atomic structure of LaCuOSe:Mg epitaxial thin film and MgO substrate Peer-reviewed

Tetsuya Tohei, Teruyasu Mizoguchi, Hidenori Hiramatsu, Hideo Hosono, Yuichi Ikuhara

MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS　173　(1-3)　229-233　2010/10

DOI： 10.1016/j.mseb.2009.12.024 　

ISSN： 0921-5107
Dislocation structures and strain fields in [111] low-angle tilt grain boundaries in zirconia bicrystals Peer-reviewed

Yuki Nohara, Eita Tochigi, Naoya Shibata, Takahisa Yamamoto, Yuichi Ikuhara

JOURNAL OF ELECTRON MICROSCOPY　59　S117-S121　2010/08

DOI： 10.1093/jmicro/dfq038 　

ISSN： 0022-0744

eISSN： 1477-9986
Homologous series of iron pnictide oxide superconductors (Fe2As2)x[Can+1(Sc,Ti)(n)O-y] (n=3,4,5) with extremely thick blocking layers Peer-reviewed

Hiraku Ogino, Shinya Sato, Kohji Kishio, Jun-ichi Shimoyama, Tetsuya Tohei, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　97　(7)　2010/08

DOI： 10.1063/1.3478850 　

ISSN： 0003-6951
Prospects for 3D imaging of dopant atoms in ceramic interfaces Peer-reviewed

Scott D. Findlay, Naoya Shibata, Shinya Azuma, Yuichi Ikuhara

JOURNAL OF ELECTRON MICROSCOPY　59　S29-S38　2010/08

DOI： 10.1093/jmicro/dfq029 　

ISSN： 0022-0744
Electrical current flow at conductive nanowires formed in GaN thin films by a dislocation template technique Peer-reviewed

Shin-ichi Amma, Yuki Tokumoto, Keiichi Edagawa, Naoya Shibata, Teruyasu Mizoguchi, Takahisa Yamamoto, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　96　(19)　2010/05

DOI： 10.1063/1.3429604 　

ISSN： 0003-6951
Phase-transformation and grain-growth kinetics in yttria-stabilized tetragonal zirconia polycrystal doped with a small amount of alumina Peer-reviewed

Koji Matsui, Hidehiro Yoshida, Yuichi Ikuhara

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY　30　(7)　1679-1690　2010/05

DOI： 10.1016/j.jeurceramsoc.2010.01.007 　

ISSN： 0955-2219

eISSN： 1873-619X
A single crystalline strontium titanate thin film transistor Peer-reviewed

Kosuke Uchida, Akira Yoshikawa, Kunihito Koumoto, Takeharu Kato, Yuichi Ikuhara, Hiromichi Ohta

JOURNAL OF APPLIED PHYSICS　107　(9)　2010/05

DOI： 10.1063/1.3407568 　

ISSN： 0021-8979

eISSN： 1089-7550
Structures of dissociated 〈1over(1, ̄) 0 0〉 dislocations and {1over(1, ̄) 0 0} stacking faults of alumina (α-Al₂O₃) Peer-reviewed

Tochigi, E., Shibata, N., Nakamura, A., Mizoguchi, T., Yamamoto, T., Ikuhara, Y.

Acta Materialia　58　(1)　208-215　2010

DOI： 10.1016/j.actamat.2009.08.067 　

ISSN： 1359-6454
HAADF-STEM observations of a σ13 grain boundary in α-Al ₂O₃ from two orthogonal directions Peer-reviewed

Azuma, S., Shibata, N., Findlay, S.D., Mizoguchi, T., Yamamoto, T., Ikuhara, Y.

Philosophical Magazine Letters　90　(8)　539-546　2010

DOI： 10.1080/09500831003630765 　

ISSN： 0950-0839 1362-3036
Wear Resistance of SiO2-Doped Y-TZP Grinding Media During Wet Milling Peer-reviewed

Hiroshi Ohnishi, Miyuki Takeuchi, Tohru Sekino, Yuichi Ikuhara, Koichi Niihara

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY　7　(4)　502-511　2010

DOI： 10.1111/j.1744-7402.2009.02360.x 　

ISSN： 1546-542X
First-principles sliding simulation of Al-terminated Sigma 13 pyramidal twin grain boundary in alpha-Al2O3 Peer-reviewed

Kaoru Nakamura, Teruyasu Mizoguchi, Naoya Shibata, Katsuyuki Matsunaga, Takahisa Yamamoto, Yuichi Ikuhara

PHILOSOPHICAL MAGAZINE LETTERS　90　(3)　159-172　2010

DOI： 10.1080/09500830903451850 　

ISSN： 0950-0839
Direct Imaging of Hydrogen within a Crystalline Environment Peer-reviewed

Scott D. Findlay, Tomohiro Saito, Naoya Shibata, Yukio Sato, Junko Matsuda, Kohta Asano, Etsuo Akiba, Tsukasa Hirayama, Yuichi Ikuhara

APPLIED PHYSICS EXPRESS　3　(11)　2010

DOI： 10.1143/APEX.3.116603 　

ISSN： 1882-0778

eISSN： 1882-0786
Oxygen Adsorption on Anatase TiO2 (101) and (001) Surfaces from First Principles Peer-reviewed

Wen Zeng, Tianmo Liu, Zhongchang Wang, Susumu Tsukimoto, Mitushiro Saito, Yuichi Ikuhara

MATERIALS TRANSACTIONS　51　(1)　171-175　2010/01

DOI： 10.2320/matertrans.M2009317 　

ISSN： 1345-9678

eISSN： 1347-5320
Direct Imaging of Dopant Segregation in a Ceramic Grain Boundary

SHIBATA Naoya, AZUMA Shinya, FINDLAY Scott D., MIZOGUCHI Teruyasu, YAMAMOTO Takahisa, IKUHARA Yuichi

Bulletin of the Japan Institute of Metals　48　(12)　639-639　2009/12/01
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.48.639 　

ISSN： 1340-2625
Local Crystal Structure Analysis for La-doped SrTiO_3 Super Lattice Thin Film based on STEM and EELS

SAITO Mitsuhiro, TSUKIMOTO Susumu, WANG Zhongchang, IKUHARA Yuichi, MIZOGUCHI Teruyasu, OKUDE Masaki, OHOTOMO Akira, KAWASAKI Masashi, KITA Takuji

Bulletin of the Japan Institute of Metals　48　(12)　595-595　2009/12/01
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.48.595 　

ISSN： 1340-2625
Electric-Field Modulation of Thermopower for the KTaO3 Field-Effect Transistors Peer-reviewed

Akira Yoshikawa, Kosuke Uchida, Kunihito Koumoto, Takeharu Kato, Yuichi Ikuhara, Hiromichi Ohta

APPLIED PHYSICS EXPRESS　2　(12)　2009/12

DOI： 10.1143/APEX.2.121103 　

ISSN： 1882-0778

eISSN： 1882-0786
Crack Propagation in a Ruby Single Crystal by Femtosecond Laser Irradiation Peer-reviewed

Chiwon Moon, Shingo Kanehira, Masayuki Nishi, Kiyotaka Miura, Takayuki Nakaya, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara, Kazuyuki Hirao

JOURNAL OF THE AMERICAN CERAMIC SOCIETY　92　(12)　3118-3121　2009/12

DOI： 10.1111/j.1551-2916.2009.03353.x 　

ISSN： 0002-7820

eISSN： 1551-2916
Ohmic contacts on silicon carbide: The first monolayer and its electronic effect Peer-reviewed

Zhongchang Wang, Susumu Tsukimoto, Mitsuhiro Saito, Kazuhiro Ito, Masanori Murakami, Yuichi Ikuhara

PHYSICAL REVIEW B　80　(24)　2009/12

DOI： 10.1103/PhysRevB.80.245303 　

ISSN： 1098-0121
Interface Atomic-Scale Structure and Its Impact on Quantum Electron Transport Peer-reviewed

Zhongchang Wang, Mitsuhiro Saito, Susumu Tsukimoto, Yuichi Ikuhara

ADVANCED MATERIALS　21　(48)　4966-+　2009/12

DOI： 10.1002/adma.200900877 　

ISSN： 0935-9648
Atomic structure of threading dislocations in AlN thin films Peer-reviewed

Yuki Tokumoto, Naoya Shibata, Teruyasu Mizoguhci, Takahisa Yamamoto, Yuichi Ikuhara

PHYSICA B-CONDENSED MATTER　404　(23-24)　4886-4888　2009/12

DOI： 10.1016/j.physb.2009.08.254 　

ISSN： 0921-4526
Fabrication of electrically conductive nanowires using high-density dislocations in AlN thin films Peer-reviewed

Yuki Tokumoto, Shin-ichi Amma, Naoya Shibata, Teruyasu Mizoguchi, Keiichi Edagawa, Takahisa Yamamoto, Yuichi Ikuhara

JOURNAL OF APPLIED PHYSICS　106　(12)　2009/12

DOI： 10.1063/1.3270398 　

ISSN： 0021-8979

eISSN： 1089-7550
Selective Detection of Formaldehyde Gas Using a Cd-Doped TiO2-SnO2 Sensor Peer-reviewed

Wen Zeng, Tianmo Liu, Zhongchang Wang, Susumu Tsukimoto, Mitsuhiro Saito, Yuichi Ikuhara

SENSORS　9　(11)　9029-9038　2009/11

DOI： 10.3390/s91109029 　

ISSN： 1424-8220
Direct imaging of doped fluorine in LaFeAsO1-XFX superconductor by atomic scale spectroscopy Peer-reviewed

Tetsuya Tohei, Teruyasu Mizoguchi, Hidenori Hiramatsu, Yoichi Kamihara, Hideo Hosono, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　95　(19)　2009/11

DOI： 10.1063/1.3263148 　

ISSN： 0003-6951
Individual charge-trapping dislocations in an ionic insulator Peer-reviewed

Zhongchang Wang, Susumu Tsukimoto, Mitsuhiro Saito, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　95　(18)　2009/11

DOI： 10.1063/1.3259778 　

ISSN： 0003-6951

eISSN： 1077-3118
Atomic and electronic structure of the YBa2Cu3O7/SrTiO3 interface from first principles Peer-reviewed

Zhongchang Wang, Susumu Tsukimoto, Mitsuhiro Saito, Yuichi Ikuhara

JOURNAL OF APPLIED PHYSICS　106　(9)　2009/11

DOI： 10.1063/1.3257264 　

ISSN： 0021-8979
Atomic-scale segregation behavior of Pr at a ZnO [0001] Sigma 49 tilt grain boundary Peer-reviewed

Yukio Sato, Teruyasu Mizoguchi, Naoya Shibata, Takahisa Yamamoto, Tsukasa Hirayama, Yuichi Ikuhara

PHYSICAL REVIEW B　80　(9)　2009/09

DOI： 10.1103/PhysRevB.80.094114 　

ISSN： 1098-0121
Field-modulated thermopower in SrTiO3-based field-effect transistors with amorphous 12CaO center dot 7Al(2)O(3) glass gate insulator Peer-reviewed

Hiromichi Ohta, Yumi Masuoka, Ryoji Asahi, Takeharu Kato, Yuichi Ikuhara, Kenji Nomura, Hideo Hosono

APPLIED PHYSICS LETTERS　95　(11)　2009/09

DOI： 10.1063/1.3231873 　

ISSN： 0003-6951

eISSN： 1077-3118
Nanowire design by dislocation technology Peer-reviewed

Yuichi Ikuhara

PROGRESS IN MATERIALS SCIENCE　54　(6)　770-791　2009/08

DOI： 10.1016/j.pmatsci.2009.03.001 　

ISSN： 0079-6425

eISSN： 1873-2208
Magnetic properties of ilmenite-hematite solid-solution thin films: Direct observation of antiphase boundaries and their correlation with magnetism Peer-reviewed

Hajime Hojo, Koji Fujita, Teruyasu Mizoguchi, Kazuyuki Hirao, Isao Tanaka, Katsuhisa Tanaka, Yuichi Ikuhara

PHYSICAL REVIEW B　80　(7)　2009/08

DOI： 10.1103/PhysRevB.80.075414 　

ISSN： 1098-0121
Transmission electron microscopy and scanning transmission electron microscopy study on B-site cation ordered structures in a (1-x)Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) single crystal Peer-reviewed

Yukio Sato, Teruyasu Mizoguchi, Naoya Shibata, Hiroki Moriwake, Tsukasa Hirayama, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　95　(2)　2009/07

DOI： 10.1063/1.3183508 　

ISSN： 0003-6951

eISSN： 1077-3118
Oxide Ceramics with High Density Dislocations and Their Properties Peer-reviewed

Yuichi Ikuhara

MATERIALS TRANSACTIONS　50　(7)　1626-1632　2009/07

DOI： 10.2320/matertrans.MF200928 　

ISSN： 1345-9678

eISSN： 1347-5320
Atomic Scale Characterization of Function Providing Elements

IKUHARA Yuichi, SHIBATA Naoya, MIZOGUCHI Teruyasu, ABE Eiji

Bulletin of the Japan Institute of Metals　48　(6)　284-289　2009/06/01
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.48.284 　

ISSN： 1340-2625
Quantum electron transport through SrTiO3: Effects of dopants on conductance channel Peer-reviewed

Zhongchang Wang, Susumu Tsukimoto, Mitsuhiro Saito, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　94　(25)　2009/06

DOI： 10.1063/1.3158615 　

ISSN： 0003-6951
Preface: Special issue on nano-materials science for atomic scale modification Peer-reviewed

Ikuhara, Y., Tanaka, I., Yamamoto, T.

Materials Transactions　50　(5)　939-939　2009/05
Publisher: JAPAN INST METALS
ISSN： 1345-9678
High-Resolution Transmission Electron Microscopy Observation of Liquid-Phase Bonded Aluminum/Sapphire Interfaces Peer-reviewed

Christine Marie Montesa, Naoya Shibata, Si-Young Choi, Hiroshi Tonomura, Kazuhiro Akiyama, Yoshirou Kuromitsu, Yuichi Ikuhara

MATERIALS TRANSACTIONS　50　(5)　1037-1040　2009/05

DOI： 10.2320/matertrans.MC200810 　

ISSN： 1345-9678

eISSN： 1347-5320
Optical and Structural Characterization of InGaN/GaN Multiple Quantum Wells by Epitaxial Lateral Overgrowth Peer-reviewed

Masakazu Sugiyama, Tomonari Shioda, Yuki Tomita, Takahisa Yamamoto, Yuichi Ikuhara, Yoshiaki Nakano

MATERIALS TRANSACTIONS　50　(5)　1085-1090　2009/05

DOI： 10.2320/matertrans.MC200830 　

ISSN： 1345-9678

eISSN： 1347-5320
Growth and Microstructure of Epitaxial Ti3SiC2 Contact Layers on SiC Peer-reviewed

Susumu Tsukimoto, Kazuhiro Ito, Zhongchang Wang, Mitsuhiro Saito, Yuichi Ikuhara, Masanori Murakami

MATERIALS TRANSACTIONS　50　(5)　1071-1075　2009/05

DOI： 10.2320/matertrans.MC200831 　

ISSN： 1345-9678

eISSN： 1347-5320
Structure and Configuration of Boundary Dislocations on Low Angle Tilt Grain Boundaries in Alumina Peer-reviewed

Atsutomo Nakamura, Eita Tochigi, Naoya Shibata, Takahisa Yamamoto, Yuichi Ikuhara

MATERIALS TRANSACTIONS　50　(5)　1008-1014　2009/05

DOI： 10.2320/matertrans.MC200821 　

ISSN： 1345-9678

eISSN： 1347-5320
First Principles Study on Intrinsic Vacancies in Cubic and Orthorhombic CaTiO3 Peer-reviewed

Haksung Lee, Teruyasu Mizoguchi, Takahisa Yamamoto, Yuichi Ikuhara

MATERIALS TRANSACTIONS　50　(5)　977-983　2009/05

DOI： 10.2320/matertrans.MC200813 　

ISSN： 1345-9678

eISSN： 1347-5320
Transmission Electron Microscopy Study of Sn-Doped Sintered Indium Oxide Peer-reviewed

Yoshimitsu Ishikawa, Hitoshi Nagayama, Hirokuni Hoshino, Michiharu Ohgai, Naoya Shibata, Takahisa Yamamoto, Yuichi Ikuhara

MATERIALS TRANSACTIONS　50　(5)　959-963　2009/05

DOI： 10.2320/matertrans.MC200814 　

ISSN： 1345-9678

eISSN： 1347-5320
First Principles Calculations of Vacancy Formation Energies in Sigma 13 Pyramidal Twin Grain Boundary of alpha-Al2O3 Peer-reviewed

Nobuaki Takahashi, Teruyasu Mizoguchi, Tetsuya Tohei, Kaoru Nakamura, Tsubasa Nakagawa, Naoya Shibata, Takahisa Yamamoto, Yuichi Ikuhara

MATERIALS TRANSACTIONS　50　(5)　1019-1022　2009/05

DOI： 10.2320/matertrans.MC200825 　

ISSN： 1345-9678

eISSN： 1347-5320
Anisotropic carrier transport properties in layered cobaltate epitaxial films grown by reactive solid-phase epitaxy Peer-reviewed

Kenji Sugiura, Hiromichi Ohta, Shin-ichi Nakagawa, Rong Huang, Yuichi Ikuhara, Kenji Nomura, Hideo Hosono, Kunihito Koumoto

APPLIED PHYSICS LETTERS　94　(15)　2009/04

DOI： 10.1063/1.3119631 　

ISSN： 0003-6951

eISSN： 1077-3118
Grain boundary mobility and grain growth behavior in polycrystals with faceted wet and dry boundaries Peer-reviewed

Byung-Kwon Yoon, Si-Young Choi, Takahisa Yamamoto, Yuichi Ikuhara, Suk-Joong L. Kang

ACTA MATERIALIA　57　(7)　2128-2135　2009/04

DOI： 10.1016/j.actamat.2009.01.005 　

ISSN： 1359-6454
Structural Transformation of Ca-Arrangements and Carrier Transport Properties in Ca0.33CoO2 Epitaxial Films Peer-reviewed

Kenji Sugiura, Hiromichi Ohta, Yukiaki Ishida, Rong Huang, Tomohiro Saito, Yuichi Ikuhara, Kenji Nomura, Hideo Hosono, Kunihito Koumoto

APPLIED PHYSICS EXPRESS　2　(3)　2009/03

DOI： 10.1143/APEX.2.035503 　

ISSN： 1882-0778

eISSN： 1882-0786
Isothermal Sintering Effects on Phase Separation and Grain Growth in Yttria-Stabilized Tetragonal Zirconia Polycrystal Peer-reviewed

Koji Matsui, Hidehiro Yoshida, Yuichi Ikuhara

JOURNAL OF THE AMERICAN CERAMIC SOCIETY　92　(2)　467-475　2009/02

DOI： 10.1111/j.1551-2916.2008.02861.x 　

ISSN： 0002-7820
Direct Determination of Dopant Site Selectivity in Ordered Perovskite CaCu3Ti4O12 Polycrystals by Aberration-Corrected STEM Peer-reviewed

Si-Young Choi, Sung-Yoon Chung, Takohisa Yamamoto, Yuichi Ikuhara

ADVANCED MATERIALS　21　(8)　885-+　2009/02

DOI： 10.1002/adma.200802728 　

ISSN： 0935-9648
Interface structures of gold nanoparticles on TiO2 (110) Peer-reviewed

Shibata, N., Goto, A., Matsunaga, K., Mizoguchi, T., Findlay, S.D., Yamamoto, T., Ikuhara, Y.

Physical Review Letters　102　(13)　2009

DOI： 10.1103/PhysRevLett.102.136105 　

ISSN： 0031-9007 1079-7114
First-principles calculation of oxygen K-electron energy loss near edge structure of HfO₂ Peer-reviewed

Mizoguchi, T., Saitoh, M., Ikuhara, Y.

Journal of Physics Condensed Matter　21　(10)　2009

DOI： 10.1088/0953-8984/21/10/104212 　

ISSN： 0953-8984 1361-648X
Direct Observation of TiO₂ (110) surfaces by HVEM and HAADF STEM Peer-reviewed

Shibata, N., Goto, A., Mizoguchi, T., Findlay, S., Choi, S.Y., Yamamoto, T., Yuichi, I.

Microscopy and Microanalysis　15　(SUPPL. 2)　1194-1195　2009

DOI： 10.1017/S1431927609093775 　

ISSN： 1431-9276 1435-8115
Atomic-scale imaging of individual dopant atoms in a buried interface Peer-reviewed

Shibata, N., Findlay, S.D., Azuma, S., Mizoguchi, T., Yamamoto, T., Ikuhara, Y.

Nature Materials　8　(8)　654-658　2009

DOI： 10.1038/nmat2486 　

ISSN： 1476-4660 1476-1122
Microstructure Evolutions at Severely-deformed Austenite/Martensite Interfaces of a Layer-integrated Steel Peer-reviewed

Taisuke Hayashi, Eiji Abe, Toru Hara, Yuichi Ikuhara

ISIJ INTERNATIONAL　49　(9)　1406-1413　2009

DOI： 10.2355/isijinternational.49.1406 　

ISSN： 0915-1559
Dislocation-Free InGaAs on Si(111) Using Micro-Channel Selective-Area Metalorganic Vapor Phase Epitaxy Peer-reviewed

Momoko Deura, Takuya Hoshii, Takahisa Yamamoto, Yuichi Ikuhara, Mitsuru Takenaka, Shinichi Takagi, Yoshiaki Nakano, Masakazu Sugiyama

APPLIED PHYSICS EXPRESS　2　(1)　2009/01

DOI： 10.1143/APEX.2.011101 　

ISSN： 1882-0778
Microstructure evolution of Ca0.33CoO2 thin films investigated by high-angle annular dark-field scanning transmission electron microscopy Peer-reviewed

Rong Huang, Teruyasu Mizoguchi, Kenji Sugiura, Shin-ichi Nakagawa, Hiromichi Ohta, Tomohiro Saito, Kunihito Koumoto, Tsukasa Hirayama, Yuichi Ikuhara

JOURNAL OF MATERIALS RESEARCH　24　(1)　279-287　2009/01

DOI： 10.1557/JMR.2009.0020 　

ISSN： 0884-2914

eISSN： 2044-5326
Atomic Resolution and In-Situ Characterization of Structural Ceramics Peer-reviewed

Yuichi Ikuhara

SIAIONS AND NON-OXIDES　403　43-44　2009

DOI： 10.4028/www.scientific.net/KEM.403.43 　

ISSN： 1013-9826
Orientation-Dependent Arrangement of Antisite Defects in Lithium Iron(II) Phosphate Crystals Peer-reviewed

Sung-Yoon Chung, Si-Young Choi, Takahisa Yamamoto, Yuichi Ikuhara

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION　48　(3)　543-546　2009

DOI： 10.1002/anie.200803520 　

ISSN： 1433-7851
SiC/Ti3SiC2 interface: Atomic structure, energetics, and bonding Peer-reviewed

Zhongchang Wang, Susumu Tsukimoto, Mitsuhiro Saito, Yuichi Ikuhara

PHYSICAL REVIEW B　79　(4)　2009/01

DOI： 10.1103/PhysRevB.79.045318 　

ISSN： 1098-0121
Mechanical properties of 2.0-3.5 mol% Y2O3-stabilized zirconia polycrystals fabricated by the solid phase mixing and sintering method Peer-reviewed

Hiroshi Ohnishi, Hironori Naka, Tohru Sekino, Yuichi Ikuhara, Koichi Niihara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　116　(1360)　1270-1277　2008/12

DOI： 10.2109/jcersj2.116.1270 　

ISSN： 1882-0743

eISSN： 1348-6535
Misfit Dislocation Formation at the c/t Interphase Boundary in Y-TZP Peer-reviewed

Seiichiro Ii, Hidehiro Yoshida, Koji Matsui, Yuichi Ikuhara

JOURNAL OF THE AMERICAN CERAMIC SOCIETY　91　(11)　3810-3812　2008/11

DOI： 10.1111/j.1551-2916.2008.02747.x 　

ISSN： 0002-7820
Direct observations of Ca ordering in Ca0.33CoO2 thin films with different superstructures Peer-reviewed

Rong Huang, Teruyasu Mizoguchi, Kenji Sugiura, Hiromichi Ohta, Kunihito Koumoto, Tsukasa Hirayama, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　93　(18)　2008/11

DOI： 10.1063/1.3021369 　

ISSN： 0003-6951

eISSN： 1077-3118
Growth Mechanism and Internal Structure of Vertically Aligned Single-Walled Carbon Nanotubes Peer-reviewed

Erik Einarsson, Masayuki Kadowaki, Kazuaki Ogura, Jun Okawa, Rong Xiang, Zhengyi Zhang, Takahisa Yamamoto, Yuichi Ikuhara, Shigeo Maruyama

JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY　8　(11)　6093-6098　2008/11

DOI： 10.1166/jnn.2008.SW22 　

ISSN： 1533-4880
Cross patterning on MgO based on dislocations using femtosecond laser irradiation Peer-reviewed

Shingo Kanehira, Kiyotaka Miura, Kazuyuki Hirao, Naoya Shibata, Yuichi Ikuhara

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING　92　(4)　913-916　2008/09

DOI： 10.1007/s00339-008-4561-8 　

ISSN： 0947-8396
High-resolution transmission electron microscopy (HRTEM) observation of dislocation structures in A1N thin films Peer-reviewed

Yuki Tokumoto, Naoya Shibata, Teruyasu Mizoguchi, Masakazu Sugiyama, Yukihiro Shimogaki, Jung-Seung Yang, Takahisa Yamamoto, Yuichi Ikuhara

Journal of Materials Research　23　(8)　2188-2194　2008/08

DOI： 10.1557/jmr.2008.0265 　

ISSN： 0884-2914
Critical thickness for giant thermoelectric Seebeck coefficient of 2DEG confined in SrTiO3/SrTi0.8Nb0.2O3 superlattices Peer-reviewed

Hiromichi Ohta, Yoriko Mune, Kunihito Koumoto, Teruyasu Mizoguchi, Yuichi Ikuhara

THIN SOLID FILMS　516　(17)　5916-5920　2008/07

DOI： 10.1016/j.tsf.2007.10.034 　

ISSN： 0040-6090
Large enhancement of the thermoelectric Seebeck coefficient for amorphous oxide semiconductor superlattices with extremely thin conductive layers Peer-reviewed

Hiromichi Ohta, Rong Huang, Yuichi Ikuhara

PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS　2　(3)　105-107　2008/06

DOI： 10.1002/pssr.200802017 　

ISSN： 1862-6254

eISSN： 1862-6270
Mechanical properties of Y2O3-stabilized ZrO2 polycrystals fabricated by the solid phase mixing and sintering method Peer-reviewed

Hiroshi Ohnishi, Hironori Naka, Tohru Sekino, Yuichi Ikuhara, Koichi Niihara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　116　(1351)　491-496　2008/03

DOI： 10.2109/jcersj2.116.491 　

ISSN： 1882-0743

eISSN： 1348-6535
Atomic-scale visualization of antisite defects in LiFePO(4) Peer-reviewed

Sung-Yoon Chung, Si-Young Choi, Takahisa Yamamoto, Yuichi Ikuhara

PHYSICAL REVIEW LETTERS　100　(12)　2008/03

DOI： 10.1103/PhysRevLett.100.125502 　

ISSN： 0031-9007
PET fiber fabrics modified with bioactive titanium oxide for bone substitutes Peer-reviewed

Tadashi Kokubo, Takahiro Ueda, Masakazu Kawashita, Yuichi Ikuhara, Gikan H. Takaoka, Takashi Nakamura

JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE　19　(2)　695-702　2008/02

DOI： 10.1007/s10856-007-3103-9 　

ISSN： 0957-4530
Partial dislocation configurations in a low-angle boundary in α-Al₂O₃ Peer-reviewed

Tochigi, E., Shibata, N., Nakamura, A., Yamamoto, T., Ikuhara, Y.

Acta Materialia　56　(9)　2015-2021　2008

DOI： 10.1016/j.actamat.2007.12.041 　

ISSN： 1359-6454
Direct imaging of reconstructed atoms on TiO₂ (110) surfaces Peer-reviewed

Shibata, N., Goto, A., Choi, S.-Y., Mizoguchi, T., Findlay, S.D., Yamamoto, T., Ikuhara, Y.

Science　322　(5901)　570-573　2008

DOI： 10.1126/science.1165044 　

ISSN： 0036-8075 1095-9203
Atomic structure, electronic structure, and defect energetics in [001](310)Σ5 grain boundaries of SrTiO₃ and BaTiO₃ Peer-reviewed

Imaeda, M., Mizoguchi, T., Sato, Y., Lee, H.-S., Findlay, S.D., Shibata, N., Yamamoto, T., Ikuhara, Y.

Physical Review B - Condensed Matter and Materials Physics　78　(24)　2008

DOI： 10.1103/PhysRevB.78.245320 　

ISSN： 1098-0121 1550-235X
Origin of giant Seebeck coefficient for high density 2DEGs confined in the SrTiO3/SrTi0.8Nb0.2O3 superlattices Peer-reviewed

Yoriko Mune, Hiromichi Ohta, Teruyasu Mizoguchi, Yuichi Ikuhara, Kunihito Koumoto

THERMOELECTRIC POWER GENERATION　1044　369-+　2008

ISSN： 0272-9172
Enhanced Seebeck coefficient of amorphous oxide semiconductor superlattices Peer-reviewed

Hiromichi Ohta, Rong Huang, Yuichi Ikuhara

THERMOELECTRIC POWER GENERATION　1044　395-+　2008

ISSN： 0272-9172
Quantum size effect of 2DEG confined within BaTiO3/SrTiO3 : Nb superlattices Peer-reviewed

Yuki Nakanishi, Hiromichi Ohta, Teruyasu Mizoguchi, Yuichi Ikuhara, Kunihito Koumoto

THERMOELECTRIC POWER GENERATION　1044　375-+　2008

ISSN： 0272-9172
Site dependence and peak assignment of YBa(2)Cu(3)O(7-x)OK-edge electron energy loss near-edge fine structure Peer-reviewed

Teruyasu Mizoguchi, Maria Varela, James P. Buban, Takahisa Yamamoto, Yuichi Ikuhara

PHYSICAL REVIEW B　77　(2)　2008/01

DOI： 10.1103/PhysRevB.77.024504 　

ISSN： 1098-0121
First-principles calculation of defect energetics in cubic-BaTiO3 and a comparison with SrTiO3 Peer-reviewed

Hak-Sung Lee, Teruyasu Mizoguchi, Takahisa Yamamoto, Suk-Joong L. Kang, Yuichi Ikuhara

ACTA MATERIALIA　55　(19)　6535-6540　2007/11

DOI： 10.1016/j.actamat.2007.07.054 　

ISSN： 1359-6454
Enhanced Seebeck coefficient of quantum-confined electrons in SrTiO3/SrTi0.8Nb0.2O3 superlattices Peer-reviewed

Yoriko Mune, Hiromichi Ohta, Kunihito Koumoto, Teruyasu Mizoguchi, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　91　(19)　2007/11

DOI： 10.1063/1.2809364 　

ISSN： 0003-6951

eISSN： 1077-3118
Yttrium doping effect on oxygen grain boundary diffusion in alpha-Al2O3 Peer-reviewed

Tsubasa Nakagawa, Isao Sakaguchi, Naoya Shibata, Katsuyuki Matsunaga, Teruyasu Mizoguchi, Takahisa Yamamoto, Hajime Haneda, Yuichi Ikuhara

ACTA MATERIALIA　55　(19)　6627-6633　2007/11

DOI： 10.1016/j.actamat.2007.08.016 　

ISSN： 1359-6454
First-principles calculation of solution energy of alkaline-earth metal elements to BaTiO3 Peer-reviewed

Hiroki Moriwake, Tsukasa Hirayama, Yuichi Ikuhara, Isao Tanaka

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS　46　(10B)　7136-7140　2007/10

DOI： 10.1143/JJAP.46.7136 　

ISSN： 0021-4922
First-principles study on incident direction, individual site character, and atomic projection dependences of ELNES for perovskite compounds (vol 106, pg 92, 2006) Peer-reviewed

Teruyasu Mizoguchi, James P. Buban, Katsuyuki Matsunaga, Takahisa Yamamoto, Yuichi Ikuhara

ULTRAMICROSCOPY　107　(8)　703-704　2007/08

DOI： 10.1016/j.ultramic.2007.01.006 　

ISSN： 0304-3991
Thermoelectric properties of the layered cobaltite Ca3Co4O9 epitaxial films fabricated by topotactic ion-exchange method Peer-reviewed

Kenji Sugiura, Hiromichi Ohta, Kenji Nomura, Tomohiro Saito, Yuichi Ikuhara, Masahiro Hirano, Hideo Hosono, Kunihito Koumoto

MATERIALS TRANSACTIONS　48　(8)　2104-2107　2007/08

DOI： 10.2320/matertrans.E-MRA2007864 　

ISSN： 1345-9678

eISSN： 1347-5320
Synthesis and evaluation of bulky Y-zeolites by hydrothermal hot-pressing method Peer-reviewed

Atsushi Nakahira, Shinichi Takezoe, Yuki Yamasaki, Yukichi Sasaki, Yuichi Ikuhara

JOURNAL OF THE AMERICAN CERAMIC SOCIETY　90　(8)　2322-2326　2007/08

DOI： 10.1111/j.1551-2916.2007.01721.x 　

ISSN： 0002-7820
Diffusion model of gallium in single-crystal ZnO proposed from analysis of concentration-dependent profiles based on the Fermi-level effect Peer-reviewed

Tsubasa Nakagawa, Isao Sakaguchi, Masashi Uematsu, Yoshiyuki Sato, Naoki Ohashi, Hajime Haneda, Yuichi Ikuhara

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS　46　(7A)　4099-4101　2007/07

DOI： 10.1143/JJAP.46.4099 　

ISSN： 0021-4922
Detecting real oxygen ions in polycrystalline diamond thin film using secondary ion mass spectrometry Peer-reviewed

Tsubasa Nakagawa, Isao Sakaguchi, Hajime Haneda, Naoki Ohashi, Yuichi Ikuhara

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS　46　(6A)　3391-3393　2007/06

DOI： 10.1143/JJAP.46.3391 　

ISSN： 0021-4922
First-principles study of grain boundary sliding in alpha-Al2O3 Peer-reviewed

Kaoru Nakamura, Teruyasu Mizoguchi, Naoya Shibata, Katsuyuki Matsunaga, Takahisa Yamamoto, Yuichi Ikuhara

PHYSICAL REVIEW B　75　(18)　2007/05

DOI： 10.1103/PhysRevB.75.184109 　

ISSN： 1098-0121
Optically produced cross patterning based on local dislocations inside MgO single crystals Peer-reviewed

Shingo Kanehira, Kiyotaka Miura, Koji Fujita, Kazuyuki Hirao, Jinhai Si, Naoya Shibata, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　90　(16)　2007/04

DOI： 10.1063/1.2722669 　

ISSN： 0003-6951
Effect of alloying elements on the interfacial bonding strength and electric conductivity of carbon nano-fiber reinforced Cu matrix composites Peer-reviewed

Sang Bok Lee, Katsuyuki Matsunaga, Yuichi Ikuhara, Sang-Kwan Lee

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING　449　778-781　2007/03

DOI： 10.1016/j.msea.2006.02.377 　

ISSN： 0921-5093
Microstructure and crystal phase development of Y2O3-stabilized ZrO2 polycrystal fabricated by the solid phase mixing and sintering method Peer-reviewed

Hiroshi Ohnishi, Tetsurou Fukuhara, Toshio Kawanami, Tohru Sekino, Yuichi Ikuhara, Koichi Niihara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　115　(1339)　210-215　2007/03

DOI： 10.2109/jcersj.115.210 　

ISSN： 1882-0743

eISSN： 1348-6535
Giant thermoelectric Seebeck coefficient of two-dimensional electron gas in SrTiO3 Peer-reviewed

Hiromichi Ohta, Sungwng Kim, Yorika Mune, Teruyasu Mizoguchi, Kenji Nomura, Shingo Ohta, Takashi Nomura, Yuki Nakanishi, Yuichi Ikuhara, Masahiro Hirano, Hideo Hosono, Kunihito Koumoto

NATURE MATERIALS　6　(2)　129-134　2007/02

DOI： 10.1038/nmat1821 　

ISSN： 1476-1122

eISSN： 1476-4660
Atomic structures and electrical properties of ZnO grain boundaries Peer-reviewed

Yukio Sato, Takahisa Yamamoto, Yuichi Ikuhara

JOURNAL OF THE AMERICAN CERAMIC SOCIETY　90　(2)　337-357　2007/02

DOI： 10.1111/j.1551-2916.2006.01481.x 　

ISSN： 0002-7820

eISSN： 1551-2916
Materials Science Forum: Preface

Kang, S.-J.L., Ikuhara, Y.

Materials Science Forum　558-559　(PART 1)　2007
Publisher: Materials Science Forum
ISSN： 1662-9752 0255-5476
GRAIN-BOUNDARY ATOMIC STRUCTURES IN ZIRCONIA CERAMICS Peer-reviewed

Naoya Shibata, Fumiyasu Oba, Takahisa Yamamoto, Yuichi Ikuhara

MECHANICAL PROPERTIES AND PERFORMANCE OF ENGINEERING CERAMICS AND COMPOSITES II　27　(2)　171-+　2007

ISSN： 0196-6219
Atomic-scale processes of grain-boundary faceting in a zirconia bicrystal Peer-reviewed

Naoya Shibata, Fumiyasu Oba, Takahisa Yamamoto, Yuichi Ikuhara

RECRYSTALLIZATION AND GRAIN GROWTH III, PTS 1 AND 2　558-559　955-+　2007

DOI： 10.4028/www.scientific.net/MSF.558-559.955 　

ISSN： 0255-5476
Theoretical tensile deformation of Sigma 13 pyramidal twin grain boundary in alumina Peer-reviewed

Kaoru Nakamura, Teruyasu Mizoguchi, Naoya Shibata, Takahisa Yamamoto, Yuichi Ikuhara

INNOVATION IN CERAMICS SCIENCE AND ENGINEERING　352　21-+　2007

DOI： 10.4028/www.scientific.net/KEM.352.21 　

ISSN： 1013-9826
Grain-boundary structure and phase-transformation mechanism in yttria-stabilized tetragonal zirconia polycrystal Peer-reviewed

Koji Matsui, Hidehiro Yoshida, Yuichi Ikuhara

RECRYSTALLIZATION AND GRAIN GROWTH III, PTS 1 AND 2　558-559　921-+　2007

DOI： 10.4028/www.scientific.net/MSF.558-559.921 　

ISSN： 0255-5476
Direct Observation of Y Segregation Sites at Alumina Grain Boundary

BUBAN James P., SHIBATA Naoya, IKUHARA Yuichi, YAMAMOTO Takahisa

Materia Japan　45　(12)　852-852　2006/12/20
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.45.852 　

ISSN： 1340-2625
Structure Units of *9 Zirconia Grain Boundary

SHIBATA Naoya, IKUHARA Yuichi, OBA Fumiyasu, YAMAMOTO Takahisa

Materia Japan　45　(12)　842-842　2006/12/20
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.45.842 　

ISSN： 1340-2625
Microstructure and Concentration Distribution of Y_2O_3 in 3Y-TZP Powder

II Seiichiro, YOSHIDA Hidehiro, MATSUI Koji, IKUHARA Yuichi

Materia Japan　45　(12)　875-875　2006/12/20
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.45.875 　

ISSN： 1340-2625
Chemical bonding, interface strength, and oxygen K electron-energy-loss near-edge structure of the Cu/Al2O3 interface Peer-reviewed

Teruyasu Mizoguchi, Takeo Sasaki, Shingo Tanaka, Katsuyuki Matsunaga, Takahisa Yamamoto, Masanori Kohyama, Yuichi Ikuhara

PHYSICAL REVIEW B　74　(23)　2006/12

DOI： 10.1103/PhysRevB.74.235408 　

ISSN： 1098-0121
Oxygen pipe diffusion in sapphire basal dislocation Peer-reviewed

Tsubasa Nakagawa, Atsutomo Nakamura, Isao Sakaguchi, Naoya Shibata, K. Peter. D. Lagerlof, Takahisa Yamamoto, Hajime Haneda, Yuichi Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　114　(1335)　1013-1017　2006/11

DOI： 10.2109/jcersj.114.1013 　

ISSN： 1882-0743

eISSN： 1348-6535
Atomic structure and relaxation behavior at AlN (0001)/Al2O3(0001) interface Peer-reviewed

Yuki Tokumoto, Teruyasu Mizoguchi, Yukio Sato, Naoya Shibata, Takahisa Yamamoto, Yuichi Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　114　(1335)　1018-1021　2006/11

DOI： 10.2109/jcersj.114.1018 　

ISSN： 1882-0743

eISSN： 1348-6535
Role of Pr segregation in acceptor-state formation at ZnO grain boundaries Peer-reviewed

Yukio Sato, James P. Buban, Teruyasu Mizoguchi, Naoya Shibata, Masatada Yodogawa, Takahisa Yamamoto, Yuichi Ikuhara

PHYSICAL REVIEW LETTERS　97　(10)　2006/09

DOI： 10.1103/PhysRevLett.97.106802 　

ISSN： 0031-9007
Microstructure and surface segregation of 3 mol% Y2O3-doped ZrO2 particles Peer-reviewed

Seiichiro Ii, Hidehiro Yoshida, Koji Matsui, Nobukatsu Ohmichi, Yuichi Ikuhara

JOURNAL OF THE AMERICAN CERAMIC SOCIETY　89　(9)　2952-2955　2006/09

DOI： 10.1111/j.1551-2916.2006.01132.x 　

ISSN： 0002-7820
Inherent nanoscale bend of crystal lattice in Fe-doped calcium copper titanate Peer-reviewed

Sung-Yoon Chung, Si-Young Choi, Takahisa Yamamoto, Yuichi Ikuhara

APPLIED PHYSICS LETTERS　89　(12)　2006/09

DOI： 10.1063/1.2354470 　

ISSN： 0003-6951
Bonding nature of metal/oxide incoherent interfaces by first-principles calculations Peer-reviewed

Katsuyuki Matsunaga, Takeo Sasaki, Naoya Shibata, Teruyasu Mizoguchi, Takahisa Yamamoto, Yuichi Ikuhara

PHYSICAL REVIEW B　74　(12)　2006/09

DOI： 10.1103/PhysRevB.74.125423 　

ISSN： 1098-0121
Effect of alumina-doping on grain boundary segregation-induced phase transformation in yttria-stabilized tetragonal zirconia polycrystal Peer-reviewed

Koji Matsui, Nobukatsu Ohmichi, Michiharu Ohgai, Hidehiro Yoshida, Yuichi Ikuhara

JOURNAL OF MATERIALS RESEARCH　21　(9)　2278-2289　2006/09

DOI： 10.1557/JMR.2006.0274 　

ISSN： 0884-2914

eISSN： 2044-5326
Synthesis and characterization of bulky FSM with interconnected mesopore-networks using an HHP method Peer-reviewed

Mari Takimura, Hidezutni Nagata, Yuki Yamasaki, Toshiyuki Suzuki, Yuichi Ikuhara, Atsushi Nakahira

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　114　(1330)　554-557　2006/06

DOI： 10.2109/jcersj.114.554 　

ISSN： 1882-0743

eISSN： 1348-6535
Improvement of high temperature ductility in oxide ceramics by grain boundary nanostructure control Peer-reviewed

H. Yoshida, K. Morita, B. -N. Kim, K. Hiraga, T. Yamamoto, Y. Ikuhara

Transactions of the Materials Research Society of Japan, Vol 31, No 2　31　(2)　533-536　2006
First-principles study on incidence direction, individual site character, and atomic projection dependences of ELNES for perovskite compounds Peer-reviewed

Mizoguchi, T., Buban, J.P., Matsunaga, K., Yamamoto, T., Ikuhara, Y.

Ultramicroscopy　106　(2)　92-104　2006

DOI： 10.1016/j.ultramic.2005.06.006 　

ISSN： 0304-3991
Oxygen diffusion along symmetric [0001] tilt grain boundaries in alpha-alumina Peer-reviewed

Tsubasa Nakagawa, Isao Sakaguchi, Katsuyuki Matsunaga, Takahisa Yamamoto, Hajime Haneda, Yuichi Ikuhara

SCIENCE OF ENGINEERING CERAMICS III　317-318　415-418　2006

DOI： 10.4028/www.scientific.net/KEM.317-318.415 　

ISSN： 1013-9826
Thermoelectric properties of epitaxial films of layered cobalt oxides fabricated by topotactic ion-exchange methods Peer-reviewed

Kenji Sugiura, Hiromichi Ohta, Kenji Nomura, Tomohiro Saito, Yuichi Ikuhara, Masahiro Hirano, Hideo Hosono, Kunihito Koumoto

ICT'06: XXV INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS　99-+　2006
Facetted Structure at a *3 Zirconia Grain Boundary

SHIBATA Naoya, IKUHARA Yuichi

Materia Japan　44　(12)　963-963　2005/12/20
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.44.963 　

ISSN： 1340-2625
Grain Boundary Dependence of Dopant Segregation and Electrical Property in ZnO

SATO Yukio, OBA Fumiyasu, YODOGAWA Masatada, YAMAMOTO Takahisa, IKUHARA Yuichi

Materia Japan　44　(12)　965-965　2005/12/20
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.44.965 　

ISSN： 1340-2625
Direct Observation of Dislocation Emission from a Crack Tip in YSZ

SASAKI Takeo, TANAKA Satoshi, YAMAMOTO Takahisa, MATSUNAGA Katsuyuki, IKUHARA Yuichi

Materia Japan　44　(12)　998-998　2005/12/20
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.44.998 　

ISSN： 1340-2625
High resolution microscopy study of [001] symmetric tilt boundary with a tilt angle of 66° in rutile-type TiO ₂ bicrystal,High resolution microscopy study of [001] symmetric tilt boundary with a tilt angle of 66° in rutile-type TiO ₂ bicrystal Peer-reviewed

Ohno, T., Ii, S., Shibata, N., Matsunaga, K., Ikuhara, Y., Yamamoto, T.

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　69　(11)　1004-1009　2005/11/01

DOI： 10.2320/jinstmet.69.1004 　

ISSN： 0021-4876
Atomic Scale Investigation of Brittle Fracture in Ceramics

MATSUNAGA Katsuyuki, II Seiichiro, IWAMOTO Chihiro, YAMAMOTO Takahisa, IKUHARA Yuichi

Bulletin of the Japan Institute of Metals　44　(4)　302-307　2005/04/20
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.44.302 　

ISSN： 1340-2625
Electron transport behaviors across single grain boundaries in n-type BaTiO₃, SrTiO₃ and ZnO

Yamamoto, T., Sato, Y., Tanaka, T., Hayashi, K., Ikuhara, Y., Sakuma, T.

Journal of Materials Science　40　(4)　881-887　2005/02/01

DOI： 10.1007/s10853-005-6505-4 　

ISSN： 0022-2461
Systematic study of grain boundary atomistic structures and related properties in cubic zirconia bicrystals

Shibata, N., Oba, F., Yamamoto, T., Ikuhara, Y.

Zeitschrift fuer Metallkunde/Materials Research and Advanced Techniques　96　(2)　2005

DOI： 10.3139/146.101017 　

ISSN： 0044-3093
Grain boundary structure and properties in oxide bicrystals

Hidehiro Yoshida, Naoya Shibata, Yuichi Ikuhara

Materials Science and Technology　3　3-10　2005

ISSN： 1546-2498
Improvement of in-plane alignment and superconducting characteristics of SmBa2Cu3Oy film on textured NiO/Ni substrate by using BaZrO3 buffer layer

Teruo Izumi, Katsuya Hasegawa, Toru Izumi, Yuh Shiohara, Yoshihiro Sugawara, Tsukasa Hirayama, Fumiyasu Oba, Yuichi Ikuhara

Proceedings - Electrochemical Society　PV 2003-29　270-282　2005
Lattice strain and dislocations in polished surfaces on sapphire

Saito, T., Hirayama, T., Yamamoto, T., Ikuhara, Y.

Journal of the American Ceramic Society　88　(8)　2277-2285　2005

DOI： 10.1111/j.1551-2916.2005.00398.x 　

ISSN： 0002-7820
Localized strain and atomic structures of symmetrical tilt grain boundaries in Al₂O₃ bicrystals

Saito, T., Hirayama, T., Matsunaga, K., Yamamoto, T., Ikuhara, Y.

Journal of the Ceramic Society of Japan　113　(1321)　605-610　2005

DOI： 10.2109/jcersj.113.605 　

ISSN： 0914-5400
Nano-structured defects in an oxide superconductor induced by Au and Fe ion irradiation

Sasaki, Y., Huang, D.X., Hirayama, T., Ikuhara, Y.

Journal of the Ceramic Society of Japan　113　(1313)　107-111　2005

DOI： 10.2109/jcersj.113.107 　

ISSN： 0914-5400
Sr vacancy segregation by heat treatment at SrTiO₃ grain boundary Peer-reviewed

Mizoguchi, T., Sato, Y., Buban, J.P., Matsunaga, K., Yamamoto, T., Ikuhara, Y.

Applied Physics Letters　87　(24)　1-3　2005

DOI： 10.1063/1.2146051 　

ISSN： 0003-6951
ELNES analysis of local electronic structures at Cu/Al ₂O ₃(0001) interface Peer-reviewed

Sasaki, T., Mizoguchi, T., Matsunaga, K., Tanaka, S., Yamamoto, T., Kohyama, M., Ikuhara, Y.

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　69　(1)　86-89　2005

DOI： 10.2320/jinstmet.69.86 　

ISSN： 0021-4876
Systematic study of grain boundary atomistic structures and related properties in cubic zirconia bicrystals Peer-reviewed

Shibata, N., Oba, F., Yamamoto, T., Ikuhara, Y.

International Journal of Materials Research　96　(2)　177-185　2005

DOI： 10.3139/ijmr-2005-0031 　

ISSN： 1862-5282
Arrangement of multiple structural units in a [0001] Σ49 tilt grain boundary in ZnO Peer-reviewed

Sato, Y., Mizoguchi, T., Oba, F., Ikuhara, Y., Yamamoto, T.

Physical Review B - Condensed Matter and Materials Physics　72　(6)　2005

DOI： 10.1103/PhysRevB.72.064109 　

ISSN： 1098-0121 1550-235X
A new method for preparing plan-view TEM specimen of multilayered films using focused ion beam

Kato, T., Muroga, T., Iijima, Y., Saitoh, T., Yamada, Y., Izumi, T., Shiohara, Y., Hirayama, T., Ikuhara, Y.

Journal of Electron Microscopy　53　(5)　501-504　2004

DOI： 10.1093/jmicro/dfh065 　

ISSN： 0022-0744
Direct characterization of grain-boundary electrical activity in doped (Ba_0.6Sr_0.4)TiO₃ by combined imaging of electron-beam-induced current and electron-backscattered diffraction

Hayashi, K., Yamamoto, T., Ikuhara, Y., Sakuma, T.

Journal of the American Ceramic Society　87　(6)　1153-1156　2004

DOI： 10.1111/j.1551-2916.2004.01153.x 　

ISSN： 0002-7820
Structure, energy and solute segregation behaviour of [110] symmetric tilt grain boundaries in yttria-stabilized cubic zirconia Peer-reviewed

Shibata, N., Oba, F., Yamamoto, T., Ikuhara, Y.

Philosophical Magazine　84　(23)　2381-2415　2004

DOI： 10.1080/14786430410001693463 　

ISSN： 1478-6435
Interfacial structures of Y123 and Nd123 films formed on MgO(001) substrates by liquid phase epitaxy Peer-reviewed

Matsuda, J.S., Oba, F., Murata, T., Yamamoto, T., Ikuhara, Y., Mizuno, M., Nomura, K., Izumi, T., Shiohara, Y.

Journal of Materials Research　19　(9)　2674-2682　2004

DOI： 10.1557/JMR.2004.0353 　

ISSN： 0884-2914
Identification of native defects around grain boundary in Pr-doped ZnO bicrystal using electron energy loss spectroscopy and first-principles calculations Peer-reviewed

Sato, Y., Mizoguchi, T., Oba, F., Yodogawa, M., Yamamoto, T., Ikuhara, Y.

Applied Physics Letters　84　(26)　5311-5313　2004

DOI： 10.1063/1.1766078 　

ISSN： 0003-6951
Grain boundary dependency of nonlinear current-voltage characteristics in Pr and Co doped ZnO bicrystals Peer-reviewed

Sato, Y., Oba, F., Yodogawa, M., Yamamoto, T., Ikuhara, Y.

Journal of Applied Physics　95　(3)　1258-1264　2004

DOI： 10.1063/1.1636816 　

ISSN： 0021-8979
Effectiveness of BaZrO₃ buffer layer in SmBa₂Cu ₃O_y epitaxial growth on MgO substrate: A first-principles study Peer-reviewed

Oba, F., Sugawara, Y., Hasegawa, K., Izumi, T., Shiohara, Y., Hirayama, T., Yamamoto, T., Ikuhara, Y.

Journal of Applied Physics　95　(5)　2309-2318　2004

DOI： 10.1063/1.1641525 　

ISSN： 0021-8979
Atomic structure of [0001]-tilt grain boundaries in ZnO: A high-resolution TEM study of fiber-textured thin films Peer-reviewed

Oba, F., Ohta, H., Sato, Y., Hosono, H., Yamamoto, T., Ikuhara, Y.

Physical Review B - Condensed Matter and Materials Physics　70　(12)　2004

DOI： 10.1103/PhysRevB.70.125415 　

ISSN： 0163-1829
Multifunctional alloys obtained via a dislocation-free plastic deformation mechanism

T. Saito, T. Furuta, J. H. Hwang, S. Kuramoto, K. Nishino, N. Suzuki, R. Chen, A. Yamada, K. Ito, Y. Seno, T. Nonaka, H. Ikehata, N. Nagasako, C. Iwamoto, Y. Ikuhara, T. Sakuma

Science　300　(5618)　464-467-467　2003/04

ISSN： 0036-8075

eISSN： 1095-9203
Single-crystalline films of the homologous series InGaO3(ZnO)(m) grown by reactive solid-phase epitaxy

H Ohta, K Nomura, M Orita, M Hirano, K Ueda, T Suzuki, Y Ikuhara, H Hosono

ADVANCED FUNCTIONAL MATERIALS　13　(2)　139-144　2003/02

ISSN： 1616-301X
HRTEM characterization of atomic structures in Cu/α-Al₂O₃ (0001) interface

Sasaki, T., Matsunaga, K., Ohta, H., Hosono, H., Yamamoto, T., Ikuhara, Y.

Zairyo/Journal of the Society of Materials Science, Japan　52　(6)　2003

DOI： 10.2472/jsms.52.555 　

ISSN： 0514-5163
A new interpretation of stress relaxation behavior in Si3N 4 ceramics

Z. L. Hong, H. Yoshida, T. Sakuma, Y. Ikuhara, T. Nishimura, M. Mitomo

Key Engineering Materials　247　279-282　2003
Publisher: Trans Tech Publications Ltd
ISSN： 1662-9795 1013-9826
Atomic structures and energies of Σ7 symmetrical tilt grain boundaries in alumina bicrystals

Hitoshi Nishimura, Katsuyuki Matsunaga, Tomohiro Saito, Takahisa Yamamoto, Yuichi Ikuhara

Journal of the American Ceramic Society　86　(4)　574-80　2003
Publisher: American Ceramic Society
DOI： 10.1111/j.1151-2916.2003.tb03343.x 　

ISSN： 0002-7820
Mechanism for improvement of in-plane alignment of SmBa₂Cu₃O_y films by BaZrO₃ buffer layer on MgO substrate Peer-reviewed

Hasegawa, K., Izumi, T., Shiohara, Y., Sugawara, Y., Hirayama, T., Oba, F., Ikuhara, Y.

Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals　67　(6)　295-301　2003

DOI： 10.2320/jinstmet1952.67.6_295 　

ISSN： 0021-4876
Grain-boundary faceting at a Σ = 3, [110]/{112} grain boundary in a cubic zirconia bicrystal Peer-reviewed

Shibata, N., Oba, F., Yamamoto, T., Sakuma, T., Ikuhara, Y.

Philosophical Magazine　83　(19)　2221-2246　2003

DOI： 10.1080/0141861031000108231 　

ISSN： 1478-6435
Current-voltage characteristics of cobalt-doped inversion boundaries in zinc oxide bicrystals Peer-reviewed

Oba, F., Sato, Y., Yamamoto, T., Ikuhara, Y., Sakuma, T.

Journal of the American Ceramic Society　86　(9)　1616-1618　2003

DOI： 10.1111/j.1151-2916.2003.tb03526.x 　

ISSN： 0002-7820
Atomic and electronic structures of Cu/alpha-Al2O3 interfaces prepared by pulsed-laser deposition Peer-reviewed

Takeo Sasaki, Katsuyuki Matsunaga, Hiromichi Ohta, Hideo Hosono, Takahisa Yamamoto, Yuichi Ikuhara

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS　4　(6)　575-584　2003

DOI： 10.1016/j.stam.2003.12.003 　

ISSN： 1468-6996

eISSN： 1878-5514
Distribution and structures of nanopores in YSZ-TBC deposited by EB-PVD Peer-reviewed

Yun-Chul Jung, Takeo Sasaki, Toru Tomimatsu, Katsuyuki Matsunaga, Takahisa Yamamoto, Yutaka Kagawa, Yuichi Ikuhara

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS　4　(6)　571-574　2003

DOI： 10.1016/j.stam.2003.12.002 　

ISSN： 1468-6996

eISSN： 1878-5514
Non-linear current-voltage characteristics related to native defects in SrTiO3 and ZnO bicrystals Peer-reviewed

Yukio Sato, Tomohito Tanaka, Fumiyasu Oba, Takahisa Yamamoto, Yuichi Ikuhara, Taketo Sakuma

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS　4　(6)　605-611　2003

DOI： 10.1016/j.stam.2003.10.031 　

ISSN： 1468-6996

eISSN： 1878-5514
Materials Transactions: Preface

Yuichi Ikuhara, Isao Tanaka

Materials Transactions　43　(7)　1425　2002/07

ISSN： 1345-9678
Grain boundary and interface characterization by TEM (I)

IKUHARA Yuichi, YAMAMOTO Takahisa

kenbikyo　37　(1)　51-55　2002/03/30
Publisher: The Japanese Society of Microscopy
DOI： 10.11410/kenbikyo1950.37.51 　

ISSN： 0417-0326
Microstructural analysis of liquid-phase-sintered β-silicon carbide

Zhan, G.-D., Ikuhara, Y., Mitomo, M., Xie, R.-J., Sakuma, T., Mukherjee, A.K.

Journal of the American Ceramic Society　85　(2)　2002

DOI： 10.1111/j.1151-2916.2002.tb00107.x 　

ISSN： 0002-7820
Self-lubrication of chlorine-implanted titanium nitride coating

Aizawa, T., Akhadejdamrong, T., Iwamoto, C., Ikuhara, Y., Mitsuo, A.

Journal of the American Ceramic Society　85　(1)　2002

DOI： 10.1111/j.1151-2916.2002.tb00032.x 　

ISSN： 0002-7820
Growth model and the effect of CuO nanocrystallites on the properties of chemically derived epitaxial thin films of YBa ₂Cu ₃O _7-x

Araki, T., Niwa, T., Yamada, Y., Hirabayashi, I., Shibata, J., Ikuhara, Y., Kato, K., Kato, T., Hirayama, T.

Journal of Applied Physics　92　(6)　3318-3325　2002

DOI： 10.1063/1.1499985 　

ISSN： 0021-8979
Crystallization mechanism of Nd_1+xBa_2-xCu₃O_7-y and YBa₂Cu₃O_7-y films deposited by metalorganic deposition method using trifluoroacetates

Shibata, J., Honjo, T., Fuji, H., Araki, T., Hirabayashi, I., Hirayama, T., Izumi, T., Shiohara, Y., Yamamoto, T., Ikuhara, Y.

Journal of Materials Research　17　(6)　1266-1275　2002

DOI： 10.1557/JMR.2002.0190 　

ISSN： 0884-2914
Interfaces between solution-derived LiMn₂O₄ thin films and MgO and Au/MgO substrates Peer-reviewed

Ikuhara, Y.H., Ma, X., Iwamoto, Y., Ikuhara, Y., Kikuta, K., Hirano, S.-I.

Journal of Materials Research　17　(2)　358-366　2002

DOI： 10.1557/JMR.2002.0051 　

ISSN： 0884-2914
Current-voltage characteristics across [0001] twist boundaries in zinc oxide bicrystals Peer-reviewed

Sato, Y., Oba, F., Yamamoto, T., Ikuhara, Y., Sakuma, T.

Journal of the American Ceramic Society　85　(8)　2142-2144　2002

DOI： 10.1111/j.1151-2916.2002.tb00424.x 　

ISSN： 0002-7820
Atomic structure and solute segregation of a Σ = 3, [110]/{111} grain boundary in an yttria-stabilized cubic zirconia bicrystal Peer-reviewed

Shibata, N., Oba, F., Yamamoto, T., Ikuhara, Y., Sakuma, T.

Philosophical Magazine Letters　82　(7)　393-400　2002

DOI： 10.1080/09500830210137407 　

ISSN： 0950-0839
Electrical Properties of Co-chemical Boundary in a Semiconductive SrTiO_3 Bicrystal

YAMAMOTO Takahisa, SAKUMA Taketo, IKUHARA Yuichi

Materia Japan　40　(12)　1011-1011　2001/12/20
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.40.1011 　

ISSN： 1340-2625
A new type of stacking fault in β-SiC

Shirahata, N., Kijima, K., Ma, X., Ikuhara, Y.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers　40　(2 A)　2001

DOI： 10.1143/jjap.40.505 　

ISSN： 0021-4922
Local bonding state and tensile ductility in MO2-doped TZP (M=Ge, Ti) Peer-reviewed

A Kuwabara, S Yokota, Y Ikuhara, T Sakuma

PRICM 4: FORTH PACIFIC RIM INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS AND PROCESSING, VOLS I AND II　2069-2072　2001
Analysis of phase stability in cubic zirconia solid solutions by first principle molecular orbital method Peer-reviewed

Kuwabara, A., Ikuhara, Y., Sakuma, T.

Zairyo/Journal of the Society of Materials Science, Japan　50　(6)　619-624　2001

DOI： 10.2472/jsms.50.619 　

ISSN： 0514-5163
The instability and resulting phase transition of cubic zirconia Peer-reviewed

Shibata, N., Katamura, J., Kuwabara, A., Ikuhara, Y., Sakuma, T.

Materials Science and Engineering: A　312　(1-2)　90-98　2001

DOI： 10.1016/S0921-5093(00)01863-3 　

ISSN： 0921-5093
Grain Boundary Structure and Electronic States in Alumina Ceramics with Improved High-temperature Creep Resistance

YOSHIDA Hidehiro, IKUHARA Yuichi, SAKUMA Taketo

Materia Japan　39　(12)　992-992　2000/12/20
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.39.992 　

ISSN： 1340-2625
Grain Boundary and Localized Quantum Structures in Ceramics

IKUHARA Yuichi, YOSHIDA Hidehiro, SAKUMA Taketo

Bulletin of the Japan Institute of Metals　39　(7)　558-562　2000/07/20
Publisher: The Japan Institute of Metals and Materials
DOI： 10.2320/materia.39.558 　

ISSN： 1340-2625
Superplastic behavior of fine-grained β-silicon nitride material under compression

Zhan, G.-D., Mitomo, M., Nishimura, T., Xie, R.-J., Sakuma, T., Ikuhara, Y.

Journal of the American Ceramic Society　83　(4)　2000

DOI： 10.1111/j.1151-2916.2000.tb01283.x 　

ISSN： 0002-7820
Atomic structures and properties of systematic [0001] tilt grain boundaries in alumina Peer-reviewed

T Watanabe, H Yoshida, T Yamamoto, Y Ikuhara, T Sakuma

GRAIN BOUNDARY ENGINEERING IN CERAMICS - FROM GRAIN BOUNDARY PHENOMENA TO GRAIN BOUNDARY QUANTUM STRUCTURES　118　369-375　2000

ISSN： 1042-1122
Microstructure control in BaTiO3 sinters by a small amount of dopants Peer-reviewed

T Yamamoto, Y Ikuhara, K Hayashi, T Sakuma

GRAIN BOUNDARY ENGINEERING IN CERAMICS - FROM GRAIN BOUNDARY PHENOMENA TO GRAIN BOUNDARY QUANTUM STRUCTURES　118　207-214　2000

ISSN： 1042-1122
Electron transport across boundaries in Nb-doped SrTiO3 bicrystals

T Yamamoto, Y Ikuhara, K Hayashi, T Sakuma

GRAIN BOUNDARY ENGINEERING IN CERAMICS - FROM GRAIN BOUNDARY PHENOMENA TO GRAIN BOUNDARY QUANTUM STRUCTURES　118　266-272　2000

ISSN： 1042-1122
Electronic conduction through a grain boundary in BaTiO3 positive temperature coefficient thermistors

K Hayashi, T Yamamoto, Y Ikuhara, T Sakuma

GRAIN BOUNDARY ENGINEERING IN CERAMICS - FROM GRAIN BOUNDARY PHENOMENA TO GRAIN BOUNDARY QUANTUM STRUCTURES　118　247-254　2000

ISSN： 1042-1122
Interfacial structures of YbBa2Cu3O7-delta superconducting films deposited on SrTiO3(001) substrates by the dipping-pyrolysis process Peer-reviewed

J Shibata, T Hirayama, K Yamagiwa, Hirabayashi, I, Y Ikuhara

GRAIN BOUNDARY ENGINEERING IN CERAMICS - FROM GRAIN BOUNDARY PHENOMENA TO GRAIN BOUNDARY QUANTUM STRUCTURES　118　551-558　2000

ISSN： 1042-1122
Effects of the heat-treatment conditions on microstructures of YbBa2Cu3O7-delta superconducting films formed by the dipping-pyrolysis process Peer-reviewed

J Shibata, K Yamagiwa, Hirabayashi, I, T Hirayama, Y Ikuhara

MATERIALS SCIENCE OF NOVEL OXIDE-BASED ELECTRONICS　623　401-406　2000

ISSN： 0272-9172
Transmission electron microscopic studies of ain films formed on off-oriented R-plane of sapphire substrates by MOCVD Peer-reviewed

J Shibata, T Shibata, Y Nakamura, K Asai, H Sakai, T Hirayama, Y Ikuhara

GRAIN BOUNDARY ENGINEERING IN CERAMICS - FROM GRAIN BOUNDARY PHENOMENA TO GRAIN BOUNDARY QUANTUM STRUCTURES　118　559-566　2000

ISSN： 1042-1122
Effects of the final heat-treatment conditions on microstructures of YbBa2Cu3O7-delta superconducting final films deposited on LaAlO3(001) substrates by the dipping-pyrolysis process Peer-reviewed

J Shibata, K Yamagiwa, Hirabayashi, I, T Hirayama, Y Ikuhara

ADVANCES IN SUPERCONDUCTIVITY XII　589-591　2000
Critical current density-magnetic field curve for untwinned orthorhombic Nd_1+xBa_2-xCu₃O_7±δ single crystal and its microstructure

Oka, A., Koyama, S., Izumi, T., Shiohara, Y., Ma, X., Yamamoto, T., Ikuhara, Y., Sakuma, T., Sugawara, Y., Hirayama, T.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers　39　(12 A)　6515-6522　2000

DOI： 10.1143/jjap.39.6515 　

ISSN： 0021-4922
Transmission electron microscopic studies of YbBa₂Cu₃O_7-δ superconducting final films formed on LaAlO₃(001) substrates by the dipping-pyrolysis process

Shibata, J., Yamagiwa, K., Hirabayashi, I., Hirayama, T., Ikuhara, Y.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers　39　(6 A)　3361-3365　2000

DOI： 10.1143/jjap.39.3361 　

ISSN： 0021-4922
Grain boundary character dependence of potential barrier in barium titanate

Hayashi, K., Yamamoto, T., Ikuhara, Y., Sakuma, T.

Materials Science Forum　294-296　(294-296)　711-714　1999/12/01
Publisher: Materials Science Forum
ISSN： 1662-9752 0255-5476
Grain boundary electrical barriers in positive temperature coefficient thermistors Peer-reviewed

Hayashi, K., Yamamoto, T., Ikuhara, Y., Sakuma, T.

Journal of Applied Physics　86　(5)　2909　1999/09
Publisher: {AIP} Publishing
DOI： 10.1063/1.371140 　

ISSN： 0021-8979
HREM and FELS study for grain boundaries in BaTiO_3

YAMAMOTO Takahisa, IKUHARA Yuichi, SAKUMA Taketo

kenbikyo　34　(1)　58-60　1999/03/31
Publisher: The Japanese Society of Microscopy
DOI： 10.11410/kenbikyo1950.34.58 　

ISSN： 0417-0326
Grain boundaries in BaTiO₃ with a small cation nonstoichiometry

Yamamoto, T., Ikuhara, Y., Hayashi, K., Sakuma, T.

Key Engineering Materials　169　51-54　1999

ISSN： 1013-9826
Effects of the initial heat-treatment conditions on microstructures of YbBa₂Cu₃O_7-δ superconducting final films deposited on SrTiO₃(001) substrates by the dipping-pyrolysis process

Shibata, J., Yamagiwa, K., Hirabayashi, I., Xiuliang, M.A., Yuan, J., Hirayama, T., Ikuhara, Y.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers　38　(9 A)　5050-5053　1999

DOI： 10.1143/jjap.38.5050 　

ISSN： 0021-4922
Chemical bonding state at grain boundaries in BaTiO₃doped with a small amount of cation

Yamamoto, T., Hayashi, K., Ikuhara, Y., Sakuma, T.

Philosophical Magazine Letters　79　(6)　327-331　1999/01/01

DOI： 10.1080/095008399177165 　

ISSN： 1362-3036 0950-0839
The Role of Co Ions on the Appearance of Non-Linear I-V Characteristics of ZnO-Based Ceramics Peer-reviewed

Yodogawa, M., Ikuhara, Y., Oba, F., Tanaka, I.

Key Engineering Materials　157-158　249-255　1999
Publisher: Key Engineering Materials
ISSN： 1662-9795 1013-9826
X-ray study of residual stress distribution of ground ceramics

Sakaida, Y., Tanaka, K., Ikuhara, Y., Suzuki, K.

JSME International Journal, Series A: Mechanics and Material Engineering　41　(3)　1998

DOI： 10.1299/jsmea.41.422 　

ISSN： 1340-8046
On epitaxy and orientation relationships in bicrystals

Pirouz, P., Ernst, F., Ikuhara, Y.

Solid State Phenomena　59-60　1998
Publisher: Solid State Phenomena
DOI： 10.4028/www.scientific.net/ssp.59-60.51 　

ISSN： 1012-0394
Fabrication and characterization of Nd_1+xBa_2-xCu₃O_7-y thin films deposited by metal-organic chemical vapor deposition using liquid state sources

Kumagai, Y., Yoshida, Y., Iwata, M., Hasegawa, M., Sugawara, Y., Hirayama, T., Ikuhara, Y., Hirabayashi, I., Takai, Y.

Physica C: Superconductivity and its Applications　304　(1-2)　35-42　1998

DOI： 10.1016/S0921-4534(98)00273-1 　

ISSN： 0921-4534
Grain boundary structure in TiO₂-excess barium titanate

Yamamoto, T., Ikuhara, Y., Hayashi, K., Sakuma, T.

Journal of Materials Research　13　(12)　3449-3452　1998

DOI： 10.1557/JMR.1998.0469 　

ISSN： 0884-2914
X-ray study of residual stress distribution of ground ceramics

Sakaida, Yoshihisa, Tanaka, Keisuke, Ikuhara, Yuichi, Suzuki, Kenzi

Nippon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A　63　(612)　1997

DOI： 10.1299/kikaia.63.1681 　

ISSN： 0387-5008
Single crystal growth of Nd123 superconductive oxides: New process to control critical currents

Yuh Shiohara, Masaru Nakamura, Tsukasa Hirayama, Yuichi Ikuhara

Journal of the Korean Physical Society　31　(1)　56-59　1997

ISSN： 0374-4884
Effect of Al2O3 on high temperature mechanical properties of silicon nitride with Yb4Si2O7N2

Toshiyuki Nishimura, Mamoru Mitomo, Akira Ishida, Hidehiro Yoshida, Yuichi Ikuhara, Taketo Sakuma

Journal of the Ceramic Society of Japan　105　(9)　801-804　1997
Publisher: Ceramic Society of Japan
DOI： 10.2109/jcersj.105.801 　

ISSN： 0914-5400
Interface structure of oxide superconducting films grown by liquid phase epitaxy.

Ikuhara Yuichi, Sugawara Yoshihiro

kenbikyo　32　(3)　155-160　1997
Publisher: The Japanese Society of Microscopy
DOI： 10.11410/kenbikyo1950.32.155 　

ISSN： 0417-0326
Correlation between anomalous peak effect in magnetic hysteresis loop and nanoscale structure for NdBa₂Cu₃O_7-δ single-crystal superconductor

Nakamura, M., Hirayama, T., Yamada, Y., Ikuhara, Y., Shiohara, Y.

Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers　35　(7)　3882-3886　1996

DOI： 10.1143/jjap.35.3882 　

ISSN： 0021-4922
Transmission electron microscopic study of c -BN films deposited on a Si substrate

Watanabe, S., Miyake, S., Zhou, W., Ikuhara, Y., Suzuki, T., Murakawa, M.

Applied Physics Letters　66　3203-3203　1995

DOI： 10.1063/1.113660 　

ISSN： 0003-6951
Direct observation of hexagonal boron nitride at the grain boundary of cubic boron nitride by high resolution electron microscopy

Zhou, W.-L., Ikuhara, Y., Murakawa, M., Watanabe, S., Suzuki, T.

Applied Physics Letters　66　3287-3287　1995

DOI： 10.1063/1.113142 　

ISSN： 0003-6951
Effects of 18MeV Fe⁸⁺ ion irradiation on superconductivity and microstructure of Bi₂Sr₂CaCu₂O_x superconductor

Sasaki, Yukichi, Zhou, Weilie, Ishiguro, Yuji, Ikuhara, Yuichi

Journal of the Ceramic Society of Japan. International ed.　103　(2)　1995

ISSN： 0912-9200
Microstructures and Mechanical Properties of Bi-Sr-Ca-Cu-O/Ag Superconductor Composites Peer-reviewed

Ikuhara, Y., Suzuki, T., Michishita, K., Kubo, Y., Ikuhara, Y.

Journal of the Society of Materials Science, Japan　44　(501)　700-704　1995

DOI： 10.2472/jsms.44.700 　

ISSN： 1880-7488 0514-5163
Electrical properties of bulk BSCCO/IN interfaces Peer-reviewed

Michishita, K., Ikuhara, Y., Ikuhara, Y., Kubo, Y., Takahashi, K., Kamisada, Y., Ogawa, T.

Physica C: Superconductivity and its applications　185-189　(PART 4)　2293-2294　1991

DOI： 10.1016/0921-4534(91)91271-5 　

ISSN： 0921-4534
Structure and Strength of Grain-Boundaries in Si Bicrystals with <111> Twist Misorientations

Kazuaki Sato, Kazuaki Sato, Hirokazu Miyazaki, Hirokazu Miyazaki, Yuichi Ikuhara, Yuichi Ikuhara, Hiroaki Kurishita, Hiroaki Kurishita, Hideo Yoshinaga

Materials Transactions, JIM　31　(10)　865-872　1990

DOI： 10.2320/matertrans1989.31.865 　

ISSN： 0916-1821
Structure and strength of grain boundaries in Si bicrystals with 〈111〉 twist misorientations

Sato, Kazuaki, Miyazaki, Hirokazu, Ikuhara, Yuichi, Kurishita, Hiroaki, Yoshinaga, Hideo

Nippon Kinzoku Gakkai-si　53　(5)　1989

ISSN： 0369-4186
Carbon in plasma sintered SiC-C composites

Ikuhara, Yuichi, Suyama, Yoko, Kijima, Kazunori

Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan　97　(11)　1989

DOI： 10.2109/jcersj.97.1403 　

ISSN： 0914-5400
Grain boundary structure and strength of SiC bicrystals

Ikuhara, Yuichi, Miyazaki, Hirokazu, Kurishita, Hiroaki, Yoshinaga, Hideo

Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan　97　(12)　1989

DOI： 10.2109/jcersj.97.1511 　

ISSN： 0914-5400
Change in Grain Boundary Structure of Ain-Polytype Sialon by Electron Irradiation

Ikuhara, Y., Yoshinaga, H.

Microscopy　36　(6)　1987

DOI： 10.1093/oxfordjournals.jmicro.a050648 　

ISSN： 2050-5701 2050-5698
GRAIN BOUNDARY AND HIGH-TEMPERATURE STRENGTH OF SINTERED SiC.

Ikuhara, Yuichi, Kurishita, Hiroaki, Yoshinaga, Hideo

Yogyo Kyokai Shi/Journal of the Ceramic Society of Japan　95　(6)　1987

ISSN： 0372-7718
JOINING OF REACTION BONDED Si//3N//4 USING Al.

Ikuhara, Yuichi, Kobayashi, Masanori, Yoshinaga, Hideo

Yogyo Kyokai Shi/Journal of the Ceramic Society of Japan　95　(9)　1987

ISSN： 0372-7718
MECHANICAL PROPERTIES OF NEWLY DEVELOPED Si//3N//4-SiC COMPOSITE MATERIAL WITH RELATIVELY HIGH FLEXIBILITY.

Ikuhara, Yuichi, Ueno, Haruyuki, Yoshinaga, Hideo

Yogyo Kyokai Shi/Journal of the Ceramic Society of Japan　93　(8)　1985

ISSN： 0372-7718

Show all ︎Show first 5

Misc. 137

First-principles study on (Ba,Ca)F₂ fluoride-ion conductor

小川貴史, 佐藤和之, 森一広, 小林俊介, 森分博紀, 幾原雄一, 幾原雄一, 桑原彰秀

日本セラミックス協会秋季シンポジウム講演予稿集(Web)　37th　2024
In-situ observation of magnetic domain structures in nanocrystalline soft magnetic materials by differential-phase-contrast scanning transmission electron microscopy

Takehito Seki, Masaya Takamoto, Masayuki Ishihara, Haruhito Ishio, Yuichi Ikuhara, Naoya Shibata

Journal of the Ceramic Society of Japan　131　(10)　767-770　2023/10

DOI： 10.2109/jcersj2.23061 　

ISSN： 1882-0743

eISSN： 1348-6535
Theoretical Modeling of Cation Configurations and Li-Ion Diffusion in Solid Electrolyte LLTO

FISHER Craig A. J., 幾原裕美, 桑原彰秀, 森分博紀, 幾原雄一, 幾原雄一

日本セラミックス協会秋季シンポジウム講演予稿集(Web)　36th　2023
First-principles study on ionic conduction mechanism in (Ba,Ca) F₂ solid solution

小川貴史, 佐藤和之, 森一広, 小林俊介, 森分博紀, 幾原雄一, 桑原彰秀

電池討論会PDF要旨集(CD-ROM)　64th　2023
Post heat treatment of (Bi, K)TiO₃-based thin films prepared by hydrothermal method and their local structure

村下太一, 岡本一輝, 高橋雄真, 窪田るりか, 伊東良晴, 藤井康裕, 是枝聡肇, 清水荘雄, 小林俊介, 加藤丈晴, HUANG Hsin-Hui, 森分博紀, 幾原雄一, 幾原雄一, 舟窪浩

電子材料研究討論会プログラム講演予稿集(CD-ROM)　43rd　2023
チタン酸リチウムランタン単結晶による高リチウムイオン伝導の実証

小林俊介, 横江大作, 桑原彰秀, 幾原雄一, 幾原雄一, 川原一晃, 藤原靖幸

JFCC研究成果集　2023　2023
Liイオン電池用酸化物固体電解質-正極膜の作製と構造解析

幾原裕美, 小林俊介, FISHER Craig, 桑原彰秀, 森分博紀, 幾原雄一, 幾原雄一

JFCC研究成果集　2023　2023
First-principles calculations of fluorine-ion migration in graphite

森分博紀, FISHER Craig A.J., 小川貴史, 桑原彰秀, 幾原雄一, 幾原雄一, 丹羽栄貴, 濱口海征, 森大輔

電池討論会PDF要旨集(CD-ROM)　63rd　2022
Crystal domain orientation dependence of Lithium-Ion Conductivity in lithium lanthanum titanate single crystals

小林俊介, 横江大作, 桑原彰秀, 藤原靖幸, 川原一晃, 幾原雄一, 幾原雄一

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
Investigation of Li ion conduction and crystal domain dependence using perovskite-type oxide LLTO single crystals

小林俊介, 横江大作, 藤原靖幸, 川原一晃, 幾原雄一, 幾原雄一, 桑原彰秀

電池討論会PDF要旨集(CD-ROM)　63rd　2022
リチウムイオン電池用正極膜内部の充放電による構造変化

幾原裕美, 高翔, 高翔, FISHER Craig, 桑原彰秀, 森分博紀, 川原一晃, 石川亮, 幾原雄一, 幾原雄一

JFCC研究成果集　2022　2022
Nano-Structural Changes during Electrochemical Cycling of Oriented LiMn₂O₄ Cathodic Thin Films

幾原裕美, GAO Xiang, FISHER Craig A. J., 桑原彰秀, 森分博紀, 川原一晃, 石川亮, 幾原雄一, 幾原雄一

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
First-principles calculations of defect formation behavior and fluoride ion conduction in Sr-doped CeF₃

桑原彰秀, 小川貴史, FISHER Craig A. J., 森分博紀, 幾原雄一, 幾原雄一

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
In situ Transmission Electron Microscopic Observation of Zn Dendrite Growth Invited Peer-reviewed

Yuki Sasaki, Kaname Yoshida, Akihide Kuwabara, Yuichi Ikuhara

KENBIKYO　56　(3)　105-109　2021/12/30

DOI： 10.11410/kenbikyo.56.3_105 　
First-principles calculations on the mechanism of fluoride ion conduction in CeF₃ solid electrolyte

桑原彰秀, 小川貴史, FISHER Craig A. J., 森分博紀, 幾原雄一, 幾原雄一

電池討論会PDF要旨集(CD-ROM)　62nd　2021
Deformation and Fracture Analysis by In Situ and Atomic-resolution Transmission Electron Microscopy

Eita Tochigi, Bin Miao, Shun Kondo, Takaaki Sato, Naoya Shibata, Hiroyuki Fujita, Yuichi Ikuhara

Materia Japan　60　(1)　35-39　2021/01/01
Publisher: Japan Institute of Metals
DOI： 10.2320/materia.60.35 　

ISSN： 1340-2625
Atomic-scale Analysis of Mechanical Response of SrTiO₃by MEMS-based in Situ STEM Mechanical Testing

Tochigi, E., Sato, T., Shibata, N., Fujita, H., Ikuhara, Y.

Microscopy and Microanalysis　26　(S2)　1838-1840　2020/07
Publisher: Cambridge University Press ({CUP})
DOI： 10.1017/S1431927620019558 　

ISSN： 1435-8115 1431-9276
Structural analysis of fluoride-shuttle battery anode MgF₂ using STEM-EELS techniques

小林俊介, 桑原彰秀, 横江大作, 幾原雄一, 幾原雄一

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)　33rd　2020
Improving the depth resolution of HAADF sectioning by 3D deconvolution

Akimitsu Ishizuka, Kazuo Ishizuka, Ryo Ishikawa, Naoya Shibata, Yuichi Ikuhara, Hiroki Hashiguchi, Ryusuke Sagawa

Microscopy and Microanalysis　2020
Publisher: Cambridge University Press
DOI： 10.1017/S1431927620023843 　

ISSN： 1435-8115 1431-9276
First-principles calculations of fluoride ion conductive solid electrolyte Ba-doped LaF3

桑原彰秀, FISHER Craig A. J., 森分博紀, 幾原雄一, 幾原雄一

電池討論会PDF要旨集(CD-ROM)　61st　2020
First-principles calculations of fluoride ion conductive solid electrolyte Ba-doped LaF₃

桑原彰秀, FISHER Craig A. J., 森分博紀, 幾原雄一, 幾原雄一

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)　33rd　2020
グラファイト中フッ素イオンの伝導挙動の第一原理計算

森分博紀, FISHER Craig, 幾原裕美, 小林俊介, 桑原彰秀, 吉田要, 西藤哲史, 右京良雄, 幾原雄一

JFCC研究成果集　2019　2019
Liイオン電池用正極膜の充放電による表面構造変化

幾原裕美, 高翔, FISHER Craig, 桑原彰秀, 森分博紀, 幾原雄一

JFCC研究成果集　2019　2019
リチウム二次電池用正極膜の充放電に伴う表面構造変化

幾原裕美, GAO Xiang, FISHER Craig A. J., 桑原彰秀, 森分博紀, 小浜恵一, 幾原雄一

日本セラミックス協会年会講演予稿集(CD-ROM)　2019　2019
理論計算によるLLNbO固体電解質の構造・特性へ与える急冷処理の影響

FISHER C. A. J., HU X., 幾原裕美, 森分博紀, 小浜恵一, 幾原雄一, 幾原雄一

日本セラミックス協会年会講演予稿集(CD-ROM)　2019　2019
First-principles calculations of point defect structures in fluoride ion conductor LaF₃

桑原彰秀, FISHER Craig. A. J., 森分博紀, 森分博紀, 右京良雄, 幾原雄一, 幾原雄一

電池討論会PDF要旨集(CD-ROM)　60th　2019
Nanostructural changes in lithium-ion battery cathodic films during electrochemical cycling

幾原裕美, GAO Xiang, FISHER Craig A. J., 桑原彰秀, 森分博紀, 幾原雄一

電池討論会PDF要旨集(CD-ROM)　60th　2019
LiMn₂O₄中の粒界構造と電池特性-原子分解能構造解析と理論計算-

森分博紀, FISHER Craig, 幾原裕美, 小林俊介, 桑原彰秀, HU Xiaobing, 右京良雄, 幾原雄一

JFCC研究成果集　2018　2018
La_(1-x)/3Li_xNbO₃固体電解質の熱処理によるナノ構造変化

幾原裕美, HU Xiaobing, 小林俊介, FISHER Craig A. J., 森分博紀, 幾原雄一, 藤原靖幸, 干川圭吾, 小浜恵一, 射場英紀

日本セラミックス協会年会講演予稿集(CD-ROM)　2018　2018
Redox reactions and electronic structure changes in olivine-type cathodes

桑原彰秀, FISHER Craig. A. J., 森分博紀, 森分博紀, 右京良雄, 幾原雄一, 幾原雄一

電池討論会講演要旨集　59th　2018
Relationship between nanostructure and Li ionic conductivity of solid electrolyte La_(1-X)/3Li_XNbO₃

幾原裕美, 小林俊介, HU Xiaobing, FISHER Craig A. J., 森分博紀, 幾原雄一, 藤原靖幸, 干川圭吾, 小浜恵一, 射場英紀

電池討論会講演要旨集　59th　2018
First-principles calculations of fluorine-ion migration in graphite

森分博紀, 森分博紀, FISHER Craig A. J., 桑原彰秀, 吉田要, 西藤哲史, 右京良雄, 幾原雄一, 幾原雄一

電池討論会講演要旨集　59th　2018
グラファイト中フッ素イオンの伝導挙動の第一原理計算

森分博紀, 森分博紀, FISHER Craig A. J., 桑原彰秀, 吉田要, 西藤哲史, 右京良雄, 幾原雄一, 幾原雄一

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
刺激応答性コロイド液晶の開発

中山真成, 梶山智司, 西村達也, 熊本明仁, 幾原雄一, 山登正文, 加藤隆史

高分子学会予稿集(CD-ROM)　66　(1)　2017
La_(1-x)/3Li_xNbO₃固体電解質のLi濃度と微細構造との相関

幾原裕美, HU X., 小林俊介, FISHER Craig A. J., 森分博紀, 藤原靖幸, 干川圭吾, 小浜恵一, 射場英紀, 幾原雄一, 幾原雄一

日本セラミックス協会年会講演予稿集(CD-ROM)　2017　2017
LiCoPO₄正極膜の充放電によるナノ構造変化

幾原裕美, 高翔, 菅原義之, FISHER Craig, 桑原彰秀, 森分博紀, 小浜恵一, 射場英紀, 幾原雄一

JFCC研究成果集　2017　2017
Atomic level microstructural changes of the thin film cathode for lithium ion batteries by electrochemical cycling

幾原裕美, GAO Xiang, 菅原義弘, FISHER Craig A. J., 桑原彰秀, 森分博紀, 小浜恵一, 射場英紀, 幾原雄一

電池討論会講演要旨集　58th　2017
Grain boundary structure in LiMn₂O₄ thin film and its influence on battery properties

森分博紀, 森分博紀, FISHER Graig A. J., 幾原裕美, 小林俊介, 桑原彰秀, HU Xiaobing, 右京良雄, 幾原雄一, 幾原雄一

電池討論会講演要旨集　58th　2017
無機/高分子ハイブリッドナノ粒子からなるコロイド液晶の開発

中山真成, 梶山智司, 西村達也, 熊本明仁, 幾原雄一, 加藤隆史

高分子学会予稿集(CD-ROM)　65　(2)　2016
化学溶液法によるLiCoPO₄正極膜の作製と微細構造解析

幾原裕美, 高翔, 菅原義之, フィッシャークレイグ, 桑原彰秀, 森分博紀, 小浜恵一, 幾原雄一

JFCC研究成果集　2016　2016
化学溶液法によるLiイオン電池用正極膜の合成と構造解析

幾原裕美, GAO X., 菅原義之, FISHER C. A. J., 桑原彰秀, 森分博紀, 幾原雄一, 幾原雄一, 小浜恵一

日本セラミックス協会年会講演予稿集(CD-ROM)　2016　2016
グラファイト負極へのNa挿入挙動の第一原理計算

森分博紀, 桑原彰秀, FISHER Craig, 幾原雄一

電池討論会講演要旨集　57th　2016
フッ素フリーMOD法Y123薄膜のJ_c特性および微細組織におよぼすClドープ効果

元木貴則, 山本明保, 荻野拓, 岸尾光二, 幾原雄一, 下山淳一, 堀井滋, 土井俊哉, 本田元気, 永石竜起

低温工学・超電導学会講演概要集　91st　2015

ISSN： 0919-5998
NiMn系スピネル正極活物質における電子構造と電極反応に関する第一原理計算

桑原彰秀, FISHER Craig A.J., 森分博紀, 小浜恵一, 幾原雄一, 幾原雄一

電気化学会大会講演要旨集(CD-ROM)　82nd　2015
LLNbO系固体電解質における変調構造のLiイオン伝導性への影響

FISHER C.A.J., GAO X., 桑原彰秀, 幾原裕美, 森分博紀, 藤原靖幸, 干川圭吾, 小浜敬一, 幾原雄一, 幾原雄一

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)　28th　2015
Na二次電池正極材料Na₄Co₃(PO₄)₂P₂O₇の電池特性の第一原理計算

森分博紀, 桑原彰秀, FISHER Craig A.J., 野瀬雅文, 中山英樹, 中西真二, 射場英紀, 幾原雄一, 幾原雄一, 幾原雄一

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)　28th　2015
Na二次電池正極材料Na₄Co₃(PO₄)₂P₂O₇の電池特性の第一原理計算

森分博紀, 桑原彰秀, FISHER Craig, 野瀬雅文, 中山英樹, 中西真二, 射場英紀, 幾原雄一

電池討論会講演要旨集　56th　2015
固体電解質Li_xLa_(1-x)/3NbO₃中のリチウムイオン伝導度へ及ぼす変調構造の影響

FISHER Craig A. J., 桑原彰秀, 幾原裕美, 森分博紀, 藤原靖幸, 干川圭吾, 小浜恵一, 幾原雄一, 幾原雄一

電池討論会講演要旨集　56th　2015
化学溶液法によるLiイオン電池用正極膜の合成と微細構造解析

幾原裕美, GAO X., 菅原義之, FISHER C. A. J., 桑原彰秀, 森分博紀, 幾原雄一, 小浜恵一

電池討論会講演要旨集　56th　2015
第一原理計算によるLiCoO₂多形体の構造と特性

フィッシャークレイグ, 桑原彰秀, 森分博紀, 幾原雄一

JFCC研究成果集　2015　2015
スピネル系正極活物質における固溶状態と電極反応機構の解析

桑原彰秀, フィッシャークレイグ, 森分博紀, 小浜恵一, 幾原雄一

JFCC研究成果集　2015　2015
Liイオン電池用固体電解質LLNbOの微細構造解析

幾原裕美, 高翔, フィッシヤークレイグ, 小林俊介, 森分博紀, 桑原彰秀, 幾原雄一, 藤原靖幸, 干川圭吾, 小浜恵一, 射場英紀

JFCC研究成果集　2015　2015
NiMnスピネル系正極材料における固溶状態と電極特性に関する第一原理計算

桑原彰秀, FISHER Carig A. J., 森分博紀, 小浜恵一, 幾原雄一, 幾原雄一

固体イオニクス討論会講演要旨集　41st　2015
固体電解質(La,Li)TiO₃の90°ドメイン構造のLi伝導特性への影響

森分博紀, GAO Xiang, 木村禎一, 桑原彰秀, 幾原裕美, FISHER Craig A.J., 大木栄幹, 當寺ケ盛健志, 小浜恵一, 幾原雄一, 幾原雄一, 幾原雄一

日本セラミックス協会年会講演予稿集(CD-ROM)　2014　2014
第一原理計算による高電位正極材料LiNi_0.5Mn_1.5O₄における固溶状態と電極特性の解析

桑原彰秀, FISHER C. A. J., 幾原裕美, 森分博紀, 小浜恵一, 幾原雄一, 幾原雄一

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)　27th　2014
Na電池正極材料Na₄Co₃(PO₄)₂P₂O₇の電子構造の第一原理計算

森分博紀, 桑原彰秀, 野瀬雅文, 中山英樹, 中西真二, 幾原雄一, 幾原雄一, 幾原雄一

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)　27th　2014
Naイオン二次電池正極材料Na₄Co₃(PO₄)₂P₂O₇の電子構造の第一原理計算

森分博紀, 桑原彰秀, 野瀬雅文, 中山英樹, 中西真二, 幾原雄一

電池討論会講演要旨集　55th　2014
固体電解質LLTO中90°ドメインのLi伝導への影響

森分博紀, 高翔, 桑原彰秀, 幾原裕美, 木村禎一, FISHER C A J, 幾原雄一, 小浜恵一, 當寺ケ盛健志

JFCC研究成果集　2014　2014
リチウムイオン二次電池用正極膜のナノ構造解析

高翔, 幾原裕美, 吉田竜視, フィッシャークレイグ, 桑原彰秀, 森分博紀, 幾原雄一, 小浜恵一

JFCC研究成果集　2014　2014
第一原理計算によるLiCoO₂ポリタイプの構造と特性

フィッシャークレイグ, 桑原明秀, 森分博紀, 幾原雄一, 幾原雄一

JFCC研究成果集　2014　2014
Atomistic study of abnormal grain growth structure in BaTiO₃ by transmission electron microscopy and scanning transmission electron microscopy Peer-reviewed

Zheng, S.J., Ma, X.L., Yamamoto, T., Ikuhara, Y.

Acta Materialia　61　(7)　2298-2307　2013/07

DOI： 10.1016/j.actamat.2012.12.046 　

ISSN： 1359-6454
Liイオン二次電池用正極膜の作製と微細構造解析

幾原裕美, GAO Xiang, FISHER Craig A.J., 桑原彰秀, 森分博紀, 幾原雄一, 幾原雄一, 大木栄幹, 小浜恵一

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)　26th　2013
NiTi系スピネル正極活物質の電極特性に関する理論計算と特性評価

桑原彰秀, 幾原裕美, GAO X, FISHER C. A. J., 森分博紀, 當寺ケ盛健志, 大木栄幹, 小浜恵一, 幾原雄一

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)　26th　2013
固体電解質(La,Li)TiO₃の90°ドメイン構造のLi伝導特性への影響

森分博紀, GAO Xiang, 木村禎一, 桑原彰秀, 幾原裕美, FISHER Craig A. J., 大木栄幹, 當寺ケ盛健志, 小浜恵一, 幾原雄一

電池討論会講演要旨集　54th　2013
リチウム二次電池用正極材料の微細構造解析

幾原裕美, 高翔, FISHER C.A.J., 桑原彰秀, 森分博紀, 幾原雄一, 大木栄幹, 小浜恵一

JFCC研究成果集　2013　2013
リチウムイオン電池用Li_0.34La_0.51TiO₃固体電解質の原子構造観察

高翔, 幾原裕美, 木村禎一, 桑原彰秀, フィッシャークレイグ, 森分博紀, 幾原雄一, 幾原雄一

日本セラミックス協会年会講演予稿集　2012　2012
LiCoO₂薄膜中のΣ2粒界におけるLi伝導の第一原理計算

森分博紀, FISHER C. A. J., 桑原彰秀, HUANG R., 幾原裕美, GAO X., 木村禎一, 幾原雄一, 幾原雄一, 幾原雄一, 一杉太郎, 大木栄幹, 大木栄幹

日本セラミックス協会年会講演予稿集　2012　2012
α-Al₂O₃基板上のLiCoO₂薄膜におけるドメイン境界

FISHER C. A. J., ZHENG S., 桑原彰秀, 森分博紀, 幾原裕美, 一杉太郎, HUANG R., 大木栄幹, 大木栄幹, 幾原雄一, 幾原雄一

日本セラミックス協会年会講演予稿集　2012　2012
第一原理計算によるスピネル型LiNi_0.5Mn_1.5O₄の電子構造と理論電位

桑原彰秀, FISHER Craig A. J., 幾原裕美, 森分博紀, 幾原雄一, 幾原雄一, 大木栄幹

日本セラミックス協会年会講演予稿集　2012　2012
正極材料LiNi_0.5Mn_1.5O₄の電子構造と理論電位の第一原理計算

桑原彰秀, FISHER Craig. A. J., 幾原裕美, 森分博紀, 幾原雄一, 幾原雄一, 大木栄幹

電気化学会大会講演要旨集　79th　2012
LiCoO₂エピタキシャル薄膜における結晶粒界の界面抵抗

熊谷明哉, 大澤健男, 清水亮太, 鈴木竜, 高木由貴, 白木将, 森分博紀, 幾原雄一, 幾原雄一, 幾原雄一, 一杉太郎

固体イオニクス討論会講演要旨集　38th　2012
LiCoO₂電池正極材料の粒界の電池特性への影響の第一原理計算

森分博紀, 桑原彰秀, フィッシャークレイグ, 幾原裕美, 黄栄, 大木栄幹, 大木栄幹, 一杉太郎, 幾原雄一

JFCC研究成果集　2012　2012
リチウムイオン電池用固体電解質の原子構造観察

高翔, 幾原裕美, 木村禎一, 森分博紀, 桑原彰秀, フィッシャークレイグ, 幾原雄一, 大木栄幹, 大木栄幹

JFCC研究成果集　2012　2012
高電位正極活物質LiNi_0.5Mn_1.5O₄の電子構造解析

桑原彰秀, FISHER C.A.J., 幾原裕美, 森分博紀, 幾原雄一, 幾原雄一, 大木栄幹, 大木栄幹

JFCC研究成果集　2012　2012
LiCoO₂エピタキシャル薄膜の電気伝導性におよぼす結晶粒界の寄与

熊谷明哉, 大澤健男, 鈴木竜, 高木由貴, 白木将, 大木栄幹, 大木栄幹, 森分博紀, 幾原雄一, 幾原雄一, 幾原雄一, 一杉太郎

応用物理学関係連合講演会講演予稿集(CD-ROM)　59th　2012
LiCoO₂エピタキシャル薄膜の伝導特性に与える結晶粒界の寄与

熊谷明哉, 大澤健男, 鈴木竜, 高木由貴, 白木将, 大木栄幹, 大木栄幹, 森分博紀, 幾原雄一, 幾原雄一, 幾原雄一, 一杉太郎

電気化学会大会講演要旨集　79th　2012
LiCoO₂薄膜中のΣ2粒界におけるLi伝導の第一原理計算

森分博紀, FISHER Craig A.J., 桑原彰秀, HUANG Rong, HUANG Rong, 幾原裕美, GAO Xiang, 木村禎一, 幾原雄一, 幾原雄一, 幾原雄一, 一杉太郎, 大木栄幹, 大木栄幹

電池討論会講演要旨集　53rd　2012
六方晶希土類複合酸化物の強誘電性と微構造

藤平哲也, 幾原雄一, 田中功, 森分博紀

日本金属学会講演概要(CD-ROM)　151st　2012

ISSN： 2433-3093
Theory and Application of Atomic-Resolution Annular Bright-Field (ABF)STEM

SHIBATA Naoya, FINDLAY Scott D., IKUHARA Yuichi

Microscopy　46　(1)　55-60　2011/03/30
Publisher: 日本顕微鏡学会
ISSN： 1349-0958
アモルファス酸化物薄膜トランジスタの熱電能電界変調

小出浩貴, 長尾有記, 河本邦仁, 高崎裕加, 梅村知也, 加藤丈晴, 幾原雄一, 太田裕道

応用物理学会学術講演会講演予稿集　2011.1　1500-1500　2011/03/09
Publisher: 公益社団法人応用物理学会
DOI： 10.11470/jsapmeeting.2011.1.0_1500 　

eISSN： 2436-7613
リチウム二次電池用LiCoO₂系正極材料における界面の構造・特性

FISHER C. A. J., 桑原彰秀, 森分博紀, 幾原裕美, HUANG R., 一杉太郎, 大木栄幹, 幾原雄一, 幾原雄一

日本セラミックス協会年会講演予稿集　2011　2011
リチウムイオン二次電池用電極材料LiCoO₂の双晶境界における各イオンの原子配列

鄭士建, クレイグフィッシャー, 一杉太郎, 森分博紀, 大木栄幹, 幾原雄一, 幾原雄一, 幾原雄一

日本セラミックス協会年会講演予稿集　2011　2011
Liイオン二次電池用LiCoO₂における界面の原子・電子構造

フィッシャークレイグ, 桑原彰秀, 森分博紀, 幾原裕美, 黄栄, 一杉太郎, 大木栄幹, 幾原雄一, 幾原雄一

日本金属学会講演概要　148th　2011

ISSN： 1342-5730
スピネル型LiNi_0.5Mn_1.5O₄正極活物質における電子構造の第一原理計算

桑原彰秀, FISHER Craig A. J., 幾原裕美, 森分博紀, 幾原雄一, 幾原雄一, 大木栄幹

日本金属学会講演概要　148th　2011

ISSN： 1342-5730
LiCoO₂薄膜中の粒界構造の第一原理計算

森分博紀, FISHER C. A. J., 桑原彰秀, HUANG R., 幾原裕美, ZHENG S., 幾原雄一, 幾原雄一, 幾原雄一, 一杉太郎, 大木栄幹, 大木栄幹

日本セラミックス協会秋季シンポジウム講演予稿集　24th　2011
化学溶液法で作製したLiイオン電池用正極材料の微細構造解析

幾原裕美, 鄭士建, 黄栄, フィッシャークレイグ, 桑原彰秀, 森分博紀, 幾原雄一, 大木栄幹

JFCC研究成果集　2011　2011
5V級正極活物質LiNi_0.5Mn_1.5O₄の電子構造と電池反応に関する第一原理計算

桑原彰秀, FISHER Craig A.J., 幾原裕美, 森分博紀, 幾原雄一, 幾原雄一, 大木栄幹

固体イオニクス討論会講演要旨集　37th　2011
Conducting Nanowires Fabricated by Dislocations Engineering in Insulating Crystals

NAKAMURA Atsutomo, MATSUNAGA Katsuyuki, YAMAMOTO Takahisa, IKUHARA Yuichi

49　(7)　310-311　2010/07/01

ISSN： 1340-2625
21pGE-16 First principles calculation of charge-orbital ordering in spinel-type LiNi_2O_4

Kuwabara Akihide, Fisher Craig A. J., Huang Rong, Ikuhara Yumi, Moriwake Hiroki, Ikuhara Yuichi, Oki Hideki

Meeting abstracts of the Physical Society of Japan　65　(1)　629-629　2010/03/01
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Ni系正極活物質Li_0.5NiO₂における電子構造の第一原理計算

桑原彰秀, FISHER Craig A. J., 黄栄, 幾原裕美, 森分博紀, 幾原雄一, 幾原雄一, 幾原雄一, 大木栄幹

日本金属学会講演概要　146th　2010

ISSN： 1342-5730
Liイオン電池用正極材料における界面の原子・電子構造

FISHER C. A. J., 森分博紀, 桑原彰秀, 幾原裕美, 黄榮, 幾原雄一, 幾原雄一, 大木栄幹

JFCC研究成果集　2010　2010
走査透過電子顕微鏡によるLi原子等軽元素の直接観察

福永啓一, 黄栄, 齋藤智浩, 森分博紀, 平山司, 大木栄幹, 一杉太郎, 幾原雄一, 幾原雄一

JFCC研究成果集　2010　2010
Liイオン二次電池正極材料LiCoO₂中のLiイオン伝導の第一原理計算

森分博紀, 桑原彰秀, フィシャークレイグ, 黄栄, 鄭士建, 幾原裕美, 幾原雄一, 幾原雄一, 大木栄幹

JFCC研究成果集　2010　2010
Microstructure and electron states of the dielectric TiO2/SrTiO3 heterointerface

Materials integration　22　(9)　38-42　2009/09
Publisher: ティー・アイ・シィー
ISSN： 1344-7858
Scanning Transmission Electron Microscopy : Advances in Ceramic Interface and Surface Characterization

SHIBATA Naoya, IKUHARA Yuichi

Ceramics Japan　44　(9)　673-678　2009/09/01
Publisher: 日本セラミックス協会
ISSN： 0009-031X
Atomic and Electronic Structure Analysis using EELS and First Principles Calculation

MIZOGUCHI Teruyasu, IKUHARA Yuichi

Ceramics Japan　44　(9)　702-707　2009/09/01
Publisher: 日本セラミックス協会
ISSN： 0009-031X
Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃単結晶中のBサイト陽イオン規則構造に関するTEM・STEM解析

佐藤幸生, 溝口照康, 柴田直哉, 森分博紀, 平山司, 幾原雄一, 幾原雄一

日本セラミックス協会秋季シンポジウム講演予稿集　22nd　2009
LiCoO₂中のLi伝導の第一原理計算

森分博紀, 桑原彰秀, FISHER Craig A. J., HUANG Rong, 幾原裕美, 幾原雄一, 幾原雄一, 大木栄幹

日本セラミックス協会秋季シンポジウム講演予稿集　22nd　2009
スピネル型Li_0.5NiO₂における電荷整列相の第一原理計算

桑原彰秀, FISHER Craig A. J., HUANG Rong, 幾原裕美, 森分博紀, 幾原雄一, 大木栄幹

日本セラミックス協会秋季シンポジウム講演予稿集　22nd　2009
Researches today: Interface and surface studies by cs-corrected STEM

Microscopy　44　(1)　65-68　2009
Publisher: 日本顕微鏡学会
ISSN： 1349-0958
Grain boundary atomic structures and electrical properties in n-type SrTiO3 single grain boundaries

Materials integration　20　(10)　8-14　2007/10
Publisher: ティー・アイ・シィー
ISSN： 1344-7858
Internal Structure of Vertically Aligned Single-Walled Carbon Nanotube Arrays

EINARSSON Erik, YAMAMOTO Takahisa, IKUHARA Yuichi, MARUYAMA Shigeo

2007　708-709　2007/09/19
Microstructure and Crystal Phase Development of Y_2O_3-Stabilized ZrO_2 Polycrystal Fabricated by the Solid Phase Mixing and Sintering Method

OHNISHI Hiroshi, FUKUHARA Tetsurou, KAWANAMI Toshio, SEKINO Tohru, IKUHARA Yuichi, NIIHARA Koichi

Journal of the Ceramic Society of Japan　115　(1339)　210-215　2007/03/01
Publisher: The Ceramic Society of Japan
ISSN： 1882-1022

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The microstructure and crystal phase in 2.8 mol% yttria-stabilized zirconia polycrystals were investigated. Starting powders were prepared by wet dispersing and mixing using an agitator mill or by the liquid phase precipitation method. The composites powders were sintered at 1275-1600℃ and then analyzed. Solid phase method (SPM) powders showed higher sinterability than those of the liquid phase precipitation method (LPM) powders, and high density samples consisting of fine grains could be obtained at lower sintering temperatures than from LPM powders. Unlike the LPM sample, the cubic and tetragonal phase was formed in the SPM sample at low sintering temperature, because there was the region of high and low Y^<3+> ion concentration in the material. As the sintering temperature increased, the cubic phase decreased and tetragonal phase increased by the progress of the diffusion of Y^<3+> ions. And then, Y^<3+> ions segregated at grain boundaries, and tetragonal grains containing cubic phase at grain boundary regions were formed. The thermal expansion curve for the SPM sample samples sintered at 1275℃ exhibited a monoclinic to tetragonal transformation during the heating stage; however, the expansion was linear during the cooling stage, as was the case for both SPM samples sintered at higher temperatures and the LPM samples. The thermal expansion behavior of the SPM sample suggested that the monoclinic phase was essentially not present within the sample, although the transformed monoclinic phase in a surface layer by grinding stresses was exist.
Nonstoichiometric dislocation cores in α-alumina

Shibata, N., Chisholm, M.F., Nakamura, A., Pennycook, S.J., Yamamoto, T., Ikuhara, Y.

Science　316　(5821)　82-85　2007

DOI： 10.1126/science.1136155 　

ISSN： 0036-8075 1095-9203
Grain boundary strengthening in alumina by rare earth impurities

Buban, J.P., Matsunaga, K., Chen, J., Shibata, N., Ching, W.Y., Yamamoto, T., Ikuhara, Y.

Science　311　(5758)　212　2006

DOI： 10.1126/science.1119839 　

ISSN： 0036-8075 1095-9203
Variation of long-period stacking order structures in rapidly solidified Mg₉₇Zn₁Y₂ alloy

Matsuda, M., Ii, S., Kawamura, Y., Ikuhara, Y., Nishida, M.

Materials Science and Engineering: A　393　(1-2)　269-274　2005/02/25

DOI： 10.1016/j.msea.2004.10.040 　

ISSN： 0921-5093
Investigation of the surface structure of zeolite A

Wakihara, T., Sasaki, Y., Kato, H., Ikuhara, Y., Okubo, T.

Physical Chemistry Chemical Physics　7　(19)　3416-3418　2005

DOI： 10.1039/b509263a 　

ISSN： 1463-9076
Control of dislocation configuration in sapphire Peer-reviewed

Nakamura, A., Lagerl{\"o}f, K.P.D., Matsunaga, K., Tohma, J., Yamamoto, T., Ikuhara, Y.

Acta Materialia　53　(2)　455-462　2005

DOI： 10.1016/j.actamat.2004.10.002 　

ISSN： 1359-6454
Direct evidence of dopant-enhanced grain-boundary sliding in yttria-stabilized zirconia bicrystals Peer-reviewed

Nakamura, A., Shibata, N., Morishige, N., Matsunaga, K., Ikuhara, Y., Yamamoto, T.

Journal of the American Ceramic Society　88　(4)　938-942　2005

DOI： 10.1111/j.1551-2916.2005.00219.x 　

ISSN： 0002-7820
Interaction between long period stacking order phase and deformation twin in rapidly solidified Mg₉₇Zn₁Y₂ alloy

Matsuda, M., Ii, S., Kawamura, Y., Ikuhara, Y., Nishida, M.

Materials Science and Engineering: A　386　(1-2)　447-452　2004/11/25

DOI： 10.1016/j.msea.2004.08.006 　

ISSN： 0921-5093
Formation of titanium-solute clusters in alumina: A first-principles study Peer-reviewed

Matsunaga, K., Mizoguchi, T., Nakamura, A., Yamamoto, T., Ikuhara, Y.

Applied Physics Letters　84　(23)　4795-4797　2004

DOI： 10.1063/1.1760598 　

ISSN： 0003-6951
Microstructure Analysis for Interface Structures and Properties of Integrated Ceramics

SHIBATA Noriyoshi, HIRAYAMA Tsukasa, IKUHARA Yuichi

Ceramics Japan　38　(7)　501-505　2003/07/01
Publisher: 日本セラミックス協会
ISSN： 0009-031X
High-resolution transmission electron microscopy and computational analyses of atomic structures of [0001] symmetric tilt grain boundaries of Al₂O₃ with equivalent grain-boundary planes

Matsunaga, K., Nishimura, H., Saito, T., Yamamoto, T., Ikuhara, Y.

Philosophical Magazine　83　(36)　4071　2003

DOI： 10.1080/14786430310001613228 　

ISSN： 1478-6435
Single-crystalline films of the homologous series InGaO₃(ZnO)_m grown by reactive solid-phase epitaxy

Ohta, H., Nomura, K., Orita, M., Hirano, M., Ueda, K., Suzuki, T., Ikuhara, Y., Hosono, H.

Advanced Functional Materials　13　(2)　139-144　2003

DOI： 10.1002/adfm.200390020 　

ISSN： 1616-301X
Imprity Effects on Grain Boundary Strength in Structural Ceramics

Annual report of the Institute of Engineering Innovation, School of Engineering, University of Tokyo　1　124-130　2002/08
Publisher: 東京大学工学部総合研究機構
ISSN： 1347-653X
Structure and Chemistry of Grain Boundaries in SiO2-doped TZP

Annual report of the Institute of Engineering Innovation, School of Engineering, University of Tokyo　1　131-144　2002/08
Publisher: 東京大学工学部総合研究機構
ISSN： 1347-653X
Grain Boundary Structure and Electrical Properties in Electroceramics

YAMAMOTO Takahisa, OBA Fumiyasu, IKUHARA Yuichi, SAKUMA Taketo

Ceramics Japan　37　(6)　435-440　2002/06/01
Publisher: 日本セラミックス協会
ISSN： 0009-031X
Development of YBCO superconducting tapes by metalorganic deposition method using trifluoroacetates : High J_c structure of YBCO films derived from highly purified coating solution

ARAKI Takeshi, MUROGA Takemi, NIWA Toshiharu, KATO Takeharu, SHIBATA Jyunko, YAMADA Yutaka, HIRAYAMA Tsukasa, IKUHARA Yuuichi, SHIOHARA Yu, HIRABAYASHI Izumi

66　107-107　2002/05/18

ISSN： 0919-5998
Grain boundary and interface structures in ceramics

Y Ikuhara

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　109　(7)　S110-S120　2001/07

DOI： 10.2109/jcersj.109.1271_S110 　

ISSN： 1882-0743

eISSN： 1348-6535
Grain Boundary Structure and High-Temperature Strength of Structural Ceramics

IKUHARA Y., YAMAMOTO T., YOSHIDA H., SAKUMA T.

27　(1)　26-26　2001/01/20

ISSN： 0387-1096
Grain boundary and interface structures in ceramics

Y. Ikuhara

Journal of the Ceramic Society of Japan　109　(1271)　S110-S120　2001
Publisher: Ceramic Society of Japan
DOI： 10.2109/jcersj.109.1271_S110 　

ISSN： 0914-5400
Structure and chemistry of grain boundaries in SiO2-doped TZP

Yuichi Ikuhara, Takahisa Yamamoto, Akihide Kuwabara, Hidehiro Yoshida, Taketo Sakuma

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS　2　(2)　411-424　2001

DOI： 10.1016/S1468-6996(01)00009-2 　

ISSN： 1468-6996

eISSN： 1878-5514
Effect of Cation Doping on the Superplastic Flow in Yttria-Stabilized Tetragonal Zirconia Polycrystals

Mimurada, J., Nakano, M., Sasaki, K., Ikuhara, Y., Sakuma, T.

Journal of the American Ceramic Society　84　(8)　2001

DOI： 10.1111/j.1151-2916.2001.tb00920.x 　

ISSN： 0002-7820
BaTiO3系PTCR素子の電気的特性に及ぼす微量陽イオン比の影響

山本剛久, 幾原雄一

東京大学工学部総合試験所年報　59　165-169　2000/10
Publisher: 東京大学工学部総合試験所
ISSN： 0371-3067
圧縮変型されたα-Al2O3単結晶の転位組織

中村篤智, 山本剛久, 幾原雄一

東京大学工学部総合試験所年報　59　159-164　2000/10
Publisher: 東京大学工学部総合試験所
ISSN： 0371-3067
単原子層対応型分析電子顕微鏡の開発

幾原雄一, 山本剛久

東京大学工学部総合試験所年報　59　153-157　2000/10
Publisher: 東京大学工学部総合試験所
ISSN： 0371-3067
Check Point in a High-Resolution Transmission Electron Microscope with X-ray Energy Dispersive Spectroscope

YAMAMOTO Takahisa, IKUHARA Yuichi

Ceramics Japan　35　(5)　382-385　2000/05/01
Publisher: 日本セラミックス協会
ISSN： 0009-031X
半導性SrTiO3双結晶の結晶粒界電気的特性

山本剛久, 幾原雄一

東京大学工学部総合試験所年報　(58)　189-193　2000/01
Publisher: 東京大学工学部総合試験所
ISSN： 0371-3067
ジルコニア双結晶の結晶粒界構造

幾原雄一, 山本剛久

東京大学工学部総合試験所年報　(58)　183-187　2000/01
Publisher: 東京大学工学部総合試験所
ISSN： 0371-3067
Formation of potential barrier related to grain-boundary character in semiconducting barium titanate

Hayashi, K., Yamamoto, T., Ikuhara, Y., Sakuma, T.

Journal of the American Ceramic Society　83　(11)　2000

DOI： 10.1111/j.1151-2916.2000.tb01616.x 　

ISSN： 0002-7820
Interface Structure of WC-Co Alloy Doped with a Small Amount of VC

JAROENWORALUCK Ankana, YAMAMOTO Takahisa, IKUHARA Yuichi, SAKUMA Taketo

38　(2)　65-66　1998/04/01

ISSN： 0288-0490
セラミック材料の物理

日刊工業新聞社(1999)
透過電子顕微鏡

日本表面科学会編、丸善株式会社(1999)
Effect of Cation Doping on the Superplastic Flow in Yttria-Stablized Tetragonal Zirconia Polycrystals

J. Am. Ceram. Soc., 84, 1817-1821 (2001)
Long columnar defects with constant column size in 180-MeV Re-irradiated Bi₂Sr₂CaCu₂O_x crystals

Phys. Rev. B, 61, 15442-15449 (2000)

DOI： 10.1103/PhysRevB.61.15442 　
Formation of Potential Barrier Related to Grain-Boundary Character in Semiconducting Barium Titanate

J. Am. Ceram. Soc., 83, 2684-2688 (2000)
Long columnar defects with constant column size in 180-MeV Re-irradiated Bi₂Sr₂CaCu₂O_x crystals

Phys. Rev. B, 61, 15442-15449 (2000)

DOI： 10.1103/PhysRevB.61.15442

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Industrial Property Rights 17

高温部品

松平恒昭, 北岡諭, 小川貴史, 柴田直哉, 幾原雄一

特許第6792791号

Property Type: Patent
セラミックス/アルミニウム接合体、パワーモジュール用基板、及び、パワーモジュール

黒光祥郎, 秋山和裕, 長瀬敏之, 長友義幸, 寺▲崎▼ 伸幸, 幾原雄一, 柴田直哉, 熊本明仁

特許第6656657号

Property Type: Patent
ノーマリーオフ特性を有する水素化ダイヤモンドMISFETの製造方法

劉江偉, 小出康夫, リャオメイヨン, 井村将隆, 松元隆夫, 柴田直哉, 幾原雄一

特許第6519792号

Property Type: Patent
導電性薄膜の製造方法

幾原雄一, 山本剛久, 柴田直哉, 水向祐樹, 小林俊介

特許第6112499号

Property Type: Patent
高導電性ジルコニア質焼結体

大西宏司, 河波利夫, 幾原雄一, 山本剛久

特許第5172076号

Property Type: Patent
単結晶性薄膜

長谷川勝哉, 和泉輝郎, 塩原融, 菅原義弘, 平山司, 大場史康, 幾原雄一

特許第4155796号

Property Type: Patent
電界放出型電子顕微鏡

山本剛久, 幾原雄一, 代田畊平, 安宅慶一, 森山和彦, 小林隆, 谷中隆志

特許第3974415号

Property Type: Patent
分析電子顕微鏡

幾原雄一, 山本剛久, 森山和彦, 小林隆, 代田畊平, 谷中隆志

特許第3909669号

Property Type: Patent

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特願2001-006956(2000)
耐剥離性被覆部材

曽根正則, 鈴木哲也, 幾原雄一

特許第3388006号

Property Type: Patent
高強度被覆体

鈴木哲也, 深野賢治, 木幡護, 幾原雄一

特許第3358696号

Property Type: Patent
カーボンナノカプセル及びその製造方法

千田正明, 徳冨勝也, 楠美智子, 幾原雄一

特許第3159880号

Property Type: Patent
電子顕微鏡用加熱装置

幾原雄一, 楠美智子, 齋藤智浩, 高須誠一, 河野智

特許第3040663号

Property Type: Patent
電子顕微鏡用試料温度測定装置

楠美智子, 幾原雄一, 齋藤智浩, 高須誠一, 河野智

特許第3040664号

Property Type: Patent
電子顕微鏡用試料引張装置

幾原雄一, 鈴木敏之, 成瀬幹夫

特許第2779075号

Property Type: Patent
走査型透過電子顕微鏡による観察方法、走査型透過電子顕微鏡システム及びプログラム

柴田直哉, 関岳人, 大江耕介, 幾原雄一

Property Type: Patent
反強磁性体、磁気抵抗素子、磁気ランダムアクセスメモリ

幾原雄一, 山本剛久, 杉山一生, 柴田直哉

Property Type: Patent
分析透過型電子顕微鏡

Property Type: Patent

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特願2001-006094(2000)

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Research Projects 34

Establishment of fundamental theories on material strengthening mechanisms based on nano-dynamics observations

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: The University of Tokyo

2022/04/27 - 2027/03/31
欠陥原子構造の解明に基づく高性能ZrO2セラミックスの合成

幾原雄一, YOO KYUNGHYEON

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別研究員奨励費

Institution: 東京大学

2023/09/27 - 2025/03/31

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本研究ではジルコニアセラミックスのモデル欠陥や単結晶を対象に、多様な先端走査透過電子顕微鏡法を高度に融合し、その局所原子構造、異種元素偏析構造、電子状態を直接計測することで、ジルコニアにおける特性発現メカニズムを解明し、高機能ジルコニアセラミックスの創製を目指す。当該年度は下記の成果が得られた。 ①単斜晶ジルコニア多結晶体の焼結：本研究では単斜晶ジルコニア粉末を用いて、異なる温度条件で単斜晶ジルコニア多結晶体の焼結を試みた。その結果、1200度の条件下で相対密度約90％の焼結体を作製することに成功した。相対密度を向上させるため、さらに高温条件で焼結を行ったが、作製された焼結体はすべて割れた。この原因として、焼結過程中に高温から冷却される際に、ジルコニアが高温安定相である正方晶から単斜晶へ相変態が発生し、それに伴う体積膨張が割れの原因と考察される。そこで本研究では冷間静水圧成形法（CIP）を用いて成形体を作製し、再度焼結温度1200度で焼結を試みた。その結果、相対密度97％の単斜晶ジルコニア焼結体を作製することに成功した。 ②正方晶ジルコニア単結晶の合成：本研究ではY2O3無添加の単斜晶ジルコニア粉末と10mol% Y2O3添加立方晶ジルコニア単結晶を接触させ、1600度で熱処理することでYの拡散を意図的に制御し、正方晶ジルコニアモデル単結晶の作製を試みた。しかし、結果として単結晶が割れており正方晶構造は確認されなかった。この問題の原因として、熱処理過程において高温から冷却される際に、ジルコニア粉末が正方晶から単斜晶へ相変態し、その結果、粉末と接触する単結晶側では粉末の体積変化による応力を受け、割れが発生したと考察される。
Analysis of mechanical properties of interfaces by in situ TEM nano-dynamics observations

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: The University of Tokyo

2022/04/01 - 2025/03/31
セラミックス欠陥の原子構造と機能特性

幾原雄一, LIN JINGHUANG

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特別研究員奨励費

Category: 特別研究員奨励費

Institution: 東京大学

2020/11 - 2022/03

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本研究では最先端の原子分解能走査透過電子顕微鏡法（STEM）を用いて、セラミックス欠陥における局所原子構造を直接観察することで、その機能発現メカニズムの解明を目指す．当該年度は酸化タングステンを主な対象として研究を進めており、下記の成果が得られた． ①酸化タングステン粒界の構造解析：パルスレーザー堆積法により、YSZ（111）基板上に成長させた酸化タングステン薄膜の構造解析を行った。その結果、結晶性の高い[001]軸配向酸化タングステン膜が得られ、多様な傾角粒界が観察された。各粒界の原子構造をさらに詳細に解析した結果、粒界はタングステンで構成される特異な五員環構造と六員環構造で記述できることが明らかになった。 ②酸素欠損酸化タングステン薄膜の構造解析：パルスレーザー堆積法を用いて、異なる酸素雰囲気下でLAO（001）基板上に作成された酸化タングステン薄膜について原子構造解析を行った。その結果、すべての薄膜において、特異なタングステンの五員環で形成されていることが明らかになった。また成膜時の酸素分圧の低下に伴い、五員環の密度が上昇することが確認された。環状明視野（ABF）―STEM法を用いて五員環を詳細に観察した結果、酸素欠損が確認され、このような酸素欠損五員環構造は酸化タングステンの電気伝導特性と熱伝導特性に影響することが示唆された。
Atom-by-atom imaging of ion dynamics in nano-structures for materials

Ikuhara Yuichi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Specially Promoted Research

Category: Grant-in-Aid for Specially Promoted Research

Institution: The University of Tokyo

2017/04 - 2022/03

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In this study, we have evolved advanced atomic-resolution S/TEM into “the direct observation method for dynamics of atoms and ions”. The newly developed fast electron beam scanning/detecting systems and environmental control holders enabled us to reveal atomic-scale materials phenomena unknown so far, such as dislocation behavior, crack propagation, atomic diffusion, and grain boundary migration. These results led the elucidation of the correlation between nanostructures and functional properties. The primary achievement of the present project is to establish the nanostructure design methods and the construction of the fundamental principles for materials development.
第一原理計算による機能材料界面の原子構造と量子輸送特性の解明

幾原雄一, LI HONGPING

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特別研究員奨励費

Category: 特別研究員奨励費

Institution: 東北大学

2016/07 - 2019/03

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本研究では、機能材料中の異種界面および双晶界面の原子構造と電子状態について、最先端の原子分解能走査透過型電子顕微鏡法(STEM)と密度汎関数法による第一原理計算により研究を行った。金属と酸化物により形成される異種界面では、界面の原子構造が機能特性に多大な影響を及ぼす。また、界面の原子構造と電子状態は、酸化物結晶の界面における極性に依存して大きく異なると考えられる。本研究では、分子線エピタキシー法によりZnO(0001)および(000-1)面にPd原子を成膜し、原子分解能STEMにより異種界面の観察を行った。STEM像の解析で得られた界面原子構造モデルをもとに約1000原子からなる超格子を作成し、第一原理計算により構造最適化を行い、界面の電子状態を計算した。Pd/ZnO界面の格子定数は18%と大きく異なるが、周期的に原子位置がずれることで不整合を緩和していることが分かった。さらに、界面の化学結合は共有結合とイオン結合の両方の性質を示し、その度合いと電子状態を定量的に明らかにした。また、磁性材料双晶界面の電子状態についても解析を行った。磁性材料の一つとして応用が期待される四酸化三鉄は、常温でフェリ磁性・半金属性を示し、スピントロニクス、触媒、医療材料など幅広い実用範囲を持つ。本研究では、まず三酸化二鉄結晶を真空中で1246℃で加熱し、四酸化三鉄双晶試料を得た。その後、STEM観察を行い3種類の安定構造を発見した。第一原理計算により原子構造と電子状態を詳しく調べた結果、双晶近傍の強・反磁性は原子構造に依存することが分かり、それぞれ特徴的な電子状態を持つことが明らかになった。また、微分位相コントラストSTEM法により磁気結合を直接観察し、理論計算による予測と整合する結果を得た。
Study of random grain boundary structures by geometrical approach

Kazutoshi Inoue, IKUHARA Yuichi, KOTANI Motoko

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2015/04 - 2018/03

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Atomic structure of symmetrical tilt GBs are analyzed from mathematical perspective. The structures of symmetrical tilt GBs can be described by a part of quasi-periodical arrangements of structural units as a realization of the lowest energy structure. Then, reference structures can linearly interpolate intermediate GBs. The major structures were well predicted by a simple decomposition formula of symmetrical tilt GBs with an algorithm due to the Farey sequence. The arrangement of structural units can be derived so as to maximize the separation of minority units which can be applicable to other GBs. The fundamental theory is necessary to be established for determining the reference structures and the stable atomic arrangements of grain boundaries.
Interfacial structural unit design for advanced stractural and functional materials

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: The University of Tokyo

2015/04 - 2018/03
Frontier explorations in nanodopant analysis

Shibata Naoya, IKUHARA YUICHI

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

Institution: The University of Tokyo

2013/06 - 2018/03

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In this project, we explored new frontiers of nano-dopant analysis using atomic-resolution scanning transmission electron microscopy (STEM). By developing new STEM techniques and applying them to the characterization of nano-dopant structures on surfaces, grain boundaries, dislocations and point defects of oxides and nitrides, we have succeeded in obtaining new structural information of nano-dopants at atomic dimensions. These results are shared with other groups and used for understanding structure-property relationships of nano-dopants inside materials. In addition, we developed a new technique called “grain boundary informatics,” which can predict stable grain boundary structures very efficiently using machine learning techniques.
機能性酸化物における格子欠陥の電子顕微鏡による動的観察

幾原雄一, GAO PENG

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特別研究員奨励費

Category: 特別研究員奨励費

Institution: 東京大学

2015/04 - 2016/03

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量子常誘電体であるチタン酸ストロンチウムは低次元化，基盤による歪み，カチオン置換などの手法により強誘電性が発現することがよく知られている．多結晶体では粒界において，点欠陥や転位などの格子欠陥が高密度に導入される．したがって，粒界近傍の領域でも同様に強誘電性が発現する可能性があり，電子物性の制御に重要な役割を果たす．本研究では，双結晶法を用いて制御された粒界を人工的に作製し，その原子・電子構造を電子顕微鏡で直接観察することにより，粒界近傍での強誘電性について検討した．電子回折法により観察したところ，所望の10°の小傾角粒界が熱拡散接合によって作製できていることを確認した．原子分解能を有する走査透過型電子顕微鏡法により二種類の転位コアが周期的に配列されていることが明らかとなった．幾何位相解析法を用いて局所的な歪みを検討したところ，10%程度の大きな歪みが転位周辺に導入されていることが分かる．さらに，この領域での電子エネルギー損失分光から，転位コア周辺では酸素空孔の導入により，一部のチタンが還元されていることが分かった．局所的な原子変位を現在解析しており，これらの解析手法を組み合わせることによって，粒界の強誘電性について今後検討する．
透過型電子顕微鏡による、セラミックス粒界構造解析

幾原雄一, MENG Fanzhi, FANZHI Meng

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特別研究員奨励費

Category: 特別研究員奨励費

Institution: 東北大学

2012/04 - 2015/03

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In this study, we fabricated a bicrystal, possessing bi-crystallographic relations of (310)[001]||(310)[001] between upper and lower crystals. Analysis of diffraction patterns confirms these orientations to within a small misfit tilt angle, and high-resolution TEM(HRTEM) reveals a perfect joining at atomic level. The HRTEM image of the grain boundary(GB) of the MgO bicrystal shows that MgO atoms were arranged symmetrically on the GB and the stronger bright spots are arranged periodically at intervals of 0.62 nm on the GB. Since this periodic arrangement of atoms is the very property of the Σ5 GB, we can confirm that a Σ5 symmetric tilt GB is manufactured. In addition, from the HAADF (High-Angle-Annular-Dark-Field) and EELS (Electron Energy-Loss Spectroscopy) mapping images, the very small amount impurities of calcium (Ca) and titanium (Ti) atoms are segregated at the GB at the same time, and formed the ordered array at the atomic scale which was not present in the natural three-dimensional structure. According to the theoretical calculations, the defects and the charge were strongly combined and formed a complex stable structure. This structure results in a significant change in properties of the sintered material. The strongly bound grain boundary which has such a stable structure, will increase the strength of the bulk material. It was found that the trace amounts of impurities in the ceramic grain boundary will make the ordered superstructure self-assembled, and greatly affect the physical properties of the ceramics materials.
Development of microscopic observation under atmospheric and stress environment and its application to ceramics

IKUHARA Yuichi, YAMAMOTO Takahisa, MIZOGUCHI Teruyasu, SHIBATA Naoya, SUSUMU Tsukimoto, SATO Yukio

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: The University of Tokyo

2010 - 2012

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In order to truly understand the structure-property relationship of materials, structure under external stimuli must be investigated. In this research project, we have developed in-situ electron microscopy under external stimuli such as mechanical stress and electric field, and we have applied these techniques to some ceramic materials. The achievement includes direct observations of the dislocation motion and twin formations under mechanical stresses and the direct observations of domain movement in piezoelectric materials, and so on.
Nano Materials Science for Atomic Scale Modification

IKUHARA Yuichi, YAMAMOTO Takahisa, MUTO Shunsuke, MORITA Seizo, TANAKA Isao, TSURUTA Kenji, TANIGUCHI Takashi, KITAOKA Satoshi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas

Category: Grant-in-Aid for Scientific Research on Priority Areas

Institution: The University of Tokyo

2007 - 2012
Nano Materials Science for Atomic Scale Modification

IKUHARA Yuichi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas

Category: Grant-in-Aid for Scientific Research on Priority Areas

Institution: The University of Tokyo

2007 - 2011
Nano-dopant superstructure analysis

IKUHARA Yuichi, MIZOGUCHI Teruyasu, SHIBATA Naoya, ABE Eiji, TSUKIMOTO Susumu, SATO Yukio

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas

Category: Grant-in-Aid for Scientific Research on Priority Areas

Institution: The University of Tokyo

2007 - 2011

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In the vicinity of the lattice defects such as interface, grain boundary, surface, and dislocation, dopants or impurities are often segregated, and they change the macroscopic properties of the materials drastically. We call these dopants "function providing elements". The purpose of this study is to reveal the atomic and electronic structures around "function providing elements" by combining advanced transmission electron microscopy and first principles calculations, to understand their role on the properties quantitatively and to obtain the guideline to design new functional materials.
収差補正STEMを用いた材料界面の原子構造・電子状態定量解析手法の確立

幾原雄一, FINDLAY Scott David

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別研究員奨励費

Institution: 東京大学

2007 - 2009

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本年度は、STEM像シミュレーション法をセラミック材料解析に適応し、界面における原子構造、特にドーパント構造の3D解析を試みた。以下にその結果を列挙する。 (1)材料内部界面の3次元ドーパント偏析構造解析イットリウムを添加したアルミナモデル界面にたいして、界面と垂直な方向からのPlan-view観察を行った場合のSTEM像理論計算を行った。その結果、低対称結晶軸からの入射によっては電子線の広がりを抑え、界面原子構造に関する3次元情報を得られる可能性が示唆された。またこの可能性を実験的に検証することにも成功した。 (2)酸素構造直接観察のための新規イメージング法の開拓酸化物界面における酸素構造を直接同定するため、新規STEMイメージング条件の開拓を行った。その結果、環状明視野領域に散乱された電子のみを用いることにより、酸素構造に敏感な像を得ることが理論的に明らかとなり、実験的にも証明することに成功した。 (3)STEMによる定量評価指針の構築本研究で得られた結果を総合すると、STEM法は材料界面の原子レベルの構造を決定する上で、極めて有力な手法である。本研究で発展させた理論計算法と実験との高度な融合により、これまで難しかった界面構造の3次元解析、軽元素構造解析、ナノ界面定量観察が可能になることが示された。このように理論アプローチを積極的に利用することにより、STEM界面解析が格段に高度化することが示された。
Development of novel ceramic device by controlling dislocation array

IKUHARA Yuichi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: The University of Tokyo

2006 - 2008
Development of High-temperature cBN Thin Film DevicesFor Severe Environments

YOSHIDA Toyonobu, IKUHARA Yuuichi, KONDO Takashi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S)

Category: Grant-in-Aid for Scientific Research (S)

Institution: The University of Tokyo

2004 - 2008
転位量子デバイスの作製とサブナノ電子構造制御

幾原雄一, 崔時榮

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別研究員奨励費

Institution: 東京大学

2006 - 2007

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平成19年度においてはNb添加SrTiO3小傾角粒界に現れる転位近傍組成・ひずみ解析と、Liイオン電池正極材料としての利用が期待されているLiFePO4のアンチサイトFe欠陥の直接観察に関する研究を行った。具体的には、Nb添加SrTiO3[001]軸10°小傾角粒界を含む双結晶を1873Kにおける熱拡散接合により作製し、双結晶粒界にあらわれる転位の中心と転位-転位間の組成を高分解能STEM-EELS法により分析した。刃状転位においてはextra-halfplaneの存在により非常に大きな応力が負荷されている。そのような状況では格子が歪み、点欠陥の形成エネルギーが変化する。古くから転位中心に酸素欠陥が濃化している可能性が議論されてきたが、転位中心の構造が不明であるためいまだ議論の余地がのこされている.今回は転位と転位の間の擬バルク領域からのEELS測定を行った。同領域はバルクと等価のHAADF-STEM像が観察される。しかしスペクトラムイメージを解析した結果、転位中心よりも多くの酸素欠陥が形成されていることが明らかになった。このことは転位中心だけでなく、転位-転位間の擬バルク領域においても特異な機能が発現することを示唆している、 LiFePO4のアンチサイト欠陥の直接観察に関しては、高純度LiFePO4ペレットを作成し、球面収差補正を装備した超高分解能STEM(JEM-2100F)を用いて高角度散乱暗視野(HAADF)像を観察した。また、中性子回折実験も行い、Feのアンチサイト欠陥が形成されていることを確認した。LiFePO4はオリビン型構造を有し、[010]方向から投影するとLiカラムを観察することができる。Fe->Liアンチサイト欠陥が及ぼすHAADF像への影響を明らかにするために、アンチサイトFe量に対するHAADF像強度の計算も行った。その結果、アンチサイトFe欠陥が約15%あれば直接観察可能であることが明らかになった。実際にHAADF像を観察した結果、Feアンチサイト欠陥の直接観察に成功した。Feは転位量子デバイスの配線材として利用する元素である。今回の結果から、Feの濃度が15%あれば可視化できることが明らかになった。以上の研究を通し、転位量子デバイスの原子・電子構造制御、機能制御に重要な知見を得ることができた。
Application of Chromium-based Nitride Films to Cutting Tools.

SUZUKI Tetsuya, NOGUCHI Hirohisa, KOMOTORI Jun, IKUHARA Yuichi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Keio University

2004 - 2006

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Metastable PVD films have been developed by incorporating second metals to binary nitride films in aims a gaining excellent mechanical and tribological properties. The cathodic arc method is a specialized method in creating metastable ternary films which cannot be synthesized under stable thermodynamic conditions. In this series of study, 2004-2006, the maximum hardness of ceramics nitride films was investigated based on the phase transition analyzed by X-ray diffraction and scanning and transmission electron microscopy. Ternary nitride films had higher microhardness than the binaries and had their own maximum hardness at certain values. The crystal structures of Ti_<1-x>Al_xN changed from the NaCl-type to Wurtzite-type at the X=0.6, while the structures of Ti_<1-x>Cr_xN and Ti_<1-x>Zr_xN retained the NaCl-type for all X values. The maximum microhardness of Cr_<1-x>Al_xN and Zr_<1-x>Al_xN were obtained at phase boundary, where films had had some special microstructure with the mixture with crystal and amorphous. Addition of Cr atoms to (Ti, Al) N films expanded maximum Al solubility up to 73 at.% without hexagonal phase segregation. The cubic Ti_xCr_yAl_zN films obtained by thermal annealing were investigated with respect to phase transition, lattice parameter and microhardness. They were kept cubic type even up to 800℃. The lattice parameter of films at decreased by 0.5% compared with to that of room temperature. Finally, cubic phase was partially transformed into hexagonal phase through the thermal diffusion process over 900℃, which decreased its microhardness.
セラミックス中への量子細線創製とナノスケール構造解析

幾原雄一, BUBAN James Paul

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別研究員奨励費

Institution: 東京大学

2004 - 2005

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本研究は,原子分解能を有する走査透過型電子顕微鏡(STEM)を主として用い,酸化アルミニウム(Al_2O_3)中の格子不整合領域(転位及び粒界)に局在化したドーパントの電子・原子構造を解析し,ドーパントによる機能発現機構の解明と機能設計のための指針を得ることを目的としている. Al_2O_3中転位を量子細線として利用するにはドーパントを転位に局在化させる必要がある。これまではTiを用いてきたが,本年度は他の3d遷移元素(V及びFe)を用いて量子細線の作成を試みた.結果的にV量子細線の作成に成功し,電気伝導を発現させることに成功した.また,STEMを用いてVナノ細線の原子・電子構造を解析した.特にZコントラスト法によるVの局所原子構造観察とEELSによる局所電子状態解析を行った.また,これと平行して第一原理バンド計算法を用いてAl_2O_3中のVの電子状態計算を行った。得られた状態密度をEELSによる実験結果と比較検討することで,Vナノ細線の電気伝導性発現の電子論的メカニズムを検討することができた. また転位以外の格子不整合領域(粒界)に局在化したドーパントの原子・電子構造解析を行った。YはAl_2O_3粒界に偏析することで高温変形挙動を劇的に改善することが知られている。Zコントラスト法によるY添加Al_2O_3双結晶粒界の観察から,Yが粒界に周期的に存在していることを明らかにした。格子静力学計算及び第一原理計算を用いた解析から,Yが粒界上の特定のサイトに存在しており,周辺の化学結合に影響していることを突き止めた。Y添加による機能改善機構を究明することができた。
DESIGN OF CERAMICS BY COTROLLING GRAIN BOUNDARY CHARACTER AND QUANTUM STRUCTURES

IKUHARA Yuichi, MATSUNAGA Katsuyuki, IWAMOTO Chihiro, YAMAMOTO Takahisa

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: The University of Tokyo

2002 - 2004

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The effect of grain boundary character on the properties in oxide ceramics by using bicrystals and tricrystals. The bicrystals of Al_2O_3,ZrO_2,ZnO and SrTiO_3 have systematically fabricated, and the grain boundary atomic structures, chemical bonding state and composition were characterized by HREM, EELS and EDS. In addition, the grain boundary energy, creep behavior and electronic properties in the respective bicrystals were measured, and the relationships of grain boundary structures, chemistry and properties were clarified from the view point of grain boundary character. The grain boundary structures in the respective bicrystals were thus analyzed by combination of HREM and static lattice calculation. HRTEM observation revealed that the present grain boundaries have asymmetrical structures with translation along the grain boundary plane. The most stable grain boundary models calculated by static lattice calculation well correspond with the HREM image. It was found that characters of grain boundary plane are an important factor to determine grain boundary atomic structures. The behavior of grain boundary sliding was also investigated by high temperature compressive creep test. The creep behavior due to grain boundary sliding was found to depend on the grain boundary structures and atomic density The [0001] tilt grain boundaries in pure alumina contained large open spaces along the boundary plane. The Y-doped boundary in alumina also exhibited a similar core structure, indicating that Y ions segregation did not change the grain boundary structure even at the atomic level. In addition, static lattice calculations showed that Y ions tended to be located around the open spaces at the grain boundary core. Therefore, it is thought that Y ions play a role for decreasing atomic diffusivity at the open grain boundary core even when their concentration is quite small. Based on the results mentioned above, importance of grain boundary atomic structures and characters were quantitatively understood, and an guideline to design ceramic grain boundary were proposed in this study.
セラミックス粒界の局在量子構造

山本剛久, 佐久間健人, 幾原雄一, 松永克志, 山本剛久, 吉田英弘, PEZZOTI Giuseppe

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特定領域研究

Category: 特定領域研究

Institution: 東京大学

2000 - 2004

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種々のセラミック材料の機能特性は、粒界原子構造に基づいて形成される粒界局在量子構造と密接に関係する。本研究では、構造用セラミックスであるアルミナやジルコニア、また、機能性セラミックであるチタン酸ストロンチウム(SrTiO3)、酸化亜鉛(ZnO)などの双結晶を作製し、粒界原子構造・電子状態と機械的・電気的特性との相関性を系統的に調べ、粒界量子構造設計に関する設計指針を構築することを目的とした。構造材については、アルミナ双結晶において極微量のイットリウム添加により高温粒界すべりが大きく抑制されることが見出された。粒界における電子状態分析を行ったところ、添加されたイットリウムが粒界における共有結合性を向上させていることが明らかとなり、添加剤による粒界電子状態制御により高温機械的特性を調整できることを突き止めた。ジルコニアにおいては主に小角粒界において形成される粒界転位構造を調べた。その結果、安定化材として添加されているイットリウムは粒界転位へ偏析し、その結果、粒界がファセット状となることが見出された、このファセット形成は高温での粒界強度と密接に関係することが分かった。一方、電子材料においては粒界転位の組織を厳密に制御することにより特異な電気特性が発現することが見出された。これは、ある傾角において転位配列が特殊な構造をとるためであり、粒界部に形成される高い応力場により粒界近傍への陽イオン空孔の集積が顕著となるためであると考えられる。ZnOについては粒界静電ポテンシャル障壁の障壁高さが粒界に偏析したPr量に依存して変化し、偏析量が多いほど高い障壁が形成されることが明らかとなった。
Development of TEM in-situ system for interface structure in ceramic material

IKUHARA Yuichi, SHIROTA Kohel, KIJSUNOKI Michiko, YAMAMOTO Takahisa

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: The University of Tokyo

2001 - 2003

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The purpose of this study is to quantitatively characterize the atomic and electronic structures in ceramic interface by in-situ transmission electron microscopy. In this year, we finally designed the in-situ TEM holder to characterize the interfacial function, and applied this technique to several model systems. We developed this project on the following points with the collaboration between University of Tokyo, Japan Fine Ceramic Center and Topcon EM service Co.. (1)Development of in-situ TEM system We developed newly designed in-situ TEM holder to characterize the interfacial function by combining the parts which were made experimentally at three institutes. In this case, the voltage applied components, the temperature measurement components and. vacuum camber attachments were optimized, and the accuracy for voltage and temperature were quantitatively confirmed. In addition, the developed TEM holder was introduced inside the high-resolution pole-piece in TEMP and the systems to be able to simultaneously characterize EDS and EELS were constructed by optimizing the measurement conditions. As the result, the point-point resolution was attained to O.2Onm at 1300℃, and the energy resolution of EELS was got up to 0.8eV at the high temperature. Furthermore, the CCD system to obtain high quality dynamic images was constructed, and the amount of the drift in this system was confirmed to be within 2nm/min.. (2)Demonstration Experiments The newly developed in-situ TEM holder to characterize the interfacial function was applied for several material systems. As the result, the dynamic behavior of micro and electronic structures at grain boundaries and dislocations, the behavior of lattice defects at high-temperatures were successfully measured for alumina, zirconia, strontium. titanate, zinc oxide and so on.
Development of a new specimen thinning technique based on the quantum process.

ICHINOSE Hideki, SHIBAYAMA Tamaki, IKUHARA Yuichi, TAKAHASHI Heisichiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

2000 - 2003

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The research is aimed to develop a new specimen thinning technique employing not an accelerated ions but a tuned short wave length electro magnetic wave to cut out atomic bonding on or near the materials surface to thin the specimen layer by layer without any damages on and in the specimen. The new technique is expected to increase the quality and the credibility of indispensable atomic structure information to the nano-technology obtained by a TEM. Apparent advancement in the precise control technique of the laser power, in development of fine focus control system and in high efficiency this technique on various materials were shown. Detailed results are as follows ; (1)A quantum-process thinning system equipped by both an ion gun and a laser gun was developed to acquire the optimum optical condition and energy density of the laser, (2)Both binary elemental covalent handing material (SiC) and a pure covalent bonding material (diamond) were thinned at the fixed wavelength to compare with Si to optimize the thinning condition. (3)A guiding rule to evaluate the size of evaporating material from the surface due to the laser irradiation was obtained. (4)A prototype of the new product was designed. The research is planned to be followed by the JST project on the next stage.
Self-Lubrication Design for Ceramic Coating via Light-Element Ion Implantation

AIZAWA Tatsuhiko, MITSUO Atsushi, SUWA Yoshihiro, MURAISHI Shinji, KUWAHARAS Hideyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: The University of Tokyo

2000 - 2002

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Ion implantation is an effective surface modification technology since various kinds of elements can be implanted into any targeting materials. In particular, various surface nano-structuring can be accommodated by the light element ion implantation. Three kinds of nanostructuring methods are introduced to investigate the nano-structuring behavior via the ion implantation and to understand the nano-hetero structuring process when these nano-structured materials are in use. Ion-plated titanium nitride films are employed as a common substrate to be nano-structured. The chemical bonding state can be gradually modified with increasing the doses of carbon via ion implantation. This first nano-structuring control in chemical bonding leads to selective hardening for designated surface area. Furthermore, hardened surface is often favored for promotion of wear resistance even in the severe wearing condition. The second nano-structuring is characterized by in-situ formation of non-equilibrium compound and by cluster formation of implanted atoms. The imposed aluminum has loose bonding with the targeting material system. This results in the formation of non-equilibrium cubic solid solution (TI, Al) N. While, a part of imposed aluminum still remains as a metallic aluminum phase. With increasing the bulk temperature, these aluminum atoms make counter diffusion from the depth to the surface, resulting in the reaction with penetrating oxygen atoms from surface and the in-situ formation of dense *-alumina surface layer. This works as a protective layer to prevent titanium nitride from further oxidation even at the elevated temperature, where the original titanium nitride films can be easily oxidized. The third nano-structuring is characterized by high mobility and reactivity of implanted atoms in TiN. The implanted chlorine has no or little distinct bonding with the lattice atoms of TiN. They might well be trapped at the dislocation in TiN without significant change of lattice constants. Since they have sufficient mobility to diffuse in the columnar TiN to the surface, the surface tribo-chemical reaction in the wear track is modified to make in-situ formation of intermediate phase oxides or Magneli phase oxides. Owing to their shearing deformation, the contact surface between TiN and work materials is self-lubricated to preserve low friction and low wearing state. This surface nano-structuring with nano-hetero structural modification becomes a new material design to improve the wear toughness.
マイクロカプセル技術を用いた材料合成過程のその場観察

幾原雄一

Offer Organization: 日本学術振興会

System: 科学研究費助成事業萌芽的研究

Category: 萌芽的研究

Institution: 東京大学

2000 - 2001

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本研究は、セラミックス微粉末を雰囲気ガスごとマイクロカプセルに閉じ込める技術を開発し、高圧ガス雰囲気中でのセラミックスの焼結・合成の素過程をその場観察することを目的として行った。本年度は、昨年度までに行った重合膜マイクロカプセルの耐熱性を向上させるために、直流プラズマ成膜装置を用いた炭化水素重合膜を作製した。具体的には、メタンガスとエタンガスの比を制御し、取適な耐熱強度を有す炭化水素系重合膜で構成されるマイクロカプセルの作製を試みた。Ar雰囲気下でカプセル化したセラミックス超微粒子の高温観察を行った結果、800℃までの温度範囲で蜂定に観察できることが分かった。さらに、耐熱性を向上させるためにPLD(パルスレーザーデポジション)法を用いて1nm以下のYSZジルコニアアモルファス膜を粉末試料にコーティングした。その結果、PLD法でYSZによるセラミックス粉末のマイクロカプセル化が可能であることがわかった。作製したマイクロカプセルを抵抗加熱TEMホルダーに固定し高温観察した結果、1000℃〜1400℃における連続的な組織変化を通常倍率(CTEM)および高分解能観察(HREM)できることが分かった。その際、低温で閉じ込められた雰囲気ガスが膨張し、マイクロカプセル内の圧力が増加するが、1200℃まではYSZコーティング膜は安定であった。また、試料の焼結・合成反応の全素過程の動的データーをビデオシステムで記録することによって、各セラミックスの焼結・合成反応の素過程を温度および時間の関数として評価することが可能であることが示唆された。
Grain Boundary Design using Ceramic Multiple Crystals and Plasticity

IKUHARA Yuichi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: The University of Tokyo

1999 - 2001

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In this year, alumina and zirconia multiple crystals were systematically fabricated, and the respective grain boundary structure and chemistry were characterized by high-resolution electron microscopy (HREM), energy dispersive X-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS). Alumina multiple crystals were fabricated by a hot joining technique at 1500 ℃ in air to obtain ten kinds of tilt grain boundaries which included small angle, CSL and high angle grain boundaries. It was found that grain boundary energy strongly depended on the grain boundary characters, e.g., there were large energy cusps at low Σ CSL grain boundaries. But, main part of grain boundary energy is likely to be due to the strain energy around the grain boundary, and the contribution of atomic configuration is not so large. Small angle grain boundaries were consisted of an array of partial dislocation with Burgers vector of 1/3[1 1^^- 00] to form the stacking faults between the dislocations. The behavior of grain boundary sliding was also investigated for typical grain boundaries by high-temperature creep test at 1400 ℃. As the result, the occurrence of grain boundary sliding was found to depend on the grain boundary geometry and atomic structure. Zirconia multiple crystals were also fabricated by a hot joining technique at 1600 ℃ in air to obtain ten kinds of tilt grain boundaries. It was found that the grain boundary structure and energy strongly depended on the grain boundary characters. For example, Σ9 grain boundary showed particularly high energy because the structure unit is highly strained at the boundary, although the amount of segregated yttrium is very large. In the case of Σ3 boundary, the atomic structure depends on the boundary planes. When boundary plane is (111), the boundary is perfectly straight along the (111) plane, however, facet structure is formed along (111)//(115) planes when the initial boundary plane is set parallel to (112). The relationship between grain boundary characters and energy will be discussed in detail from the view point of atomic structures and segregation for all kinds of grain boundaries in zirconia.
Electrical properties in semiconducting BaTiOィイD23ィエD2 bicrystals

YAMAMOTO Takahisa, IKUHARA Yuichi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: THE UNIVERSITY OF TOKYO

1998 - 1999

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BaTiOィイD23ィエD2, Which is often used as based materials for electroceramics, exhibits semiconduction when it is doped with cations whose valence is large than host cations' valence. In general, most of electroceramics are utilized for practical use as in polycrystals and their electrical properties is often closely related to their grain boundary phenomena. Therefore, it must be necessary to investigate the electrical properties directly at single grain boundaries. In this study, BaTiOィイD23ィエD2 bicrystals were fabricated and then their electrical properties were examined. The following results could be obtained. (1) It was succeeded in construction of the technique for controlling the abnormal grain growth in BaTiOィイD23ィエD2 by changing A/B-site ratio. Coarse-grained structure with a grain size of about 1mm could be obtained. (2) It was found that the electrical properties in BaTiOィイD23ィエD2 bicrystal closely depend on the grain orientation relationship. The magnitude of Positive temperature coefficient of resistivity effect decerases with an increase in the coherency at grain boundaries. (3) The similar tendency could be obtained also in SrTiOィイD23ィエD2 bicrystal, which has the same lattice structure and similar electrical properties.
ジルコニアの相転移に伴う組織形成のコンピュータシミュレーション

幾原雄一, 佐久間健人

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特定領域研究(A)

Category: 特定領域研究(A)

Institution: 東京大学

1996 - 1999

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ZrO_2-Y_2O_3系のc-t二相域内での熱処理初期段階に形成される層状組織を計算機上でシミュレートした。その結果、この組織は連続的な界面、時間経過によるY^<3+>濃度揺らぎの連続的増大といった特徴を有することが予期された。実際にこれらの特徴をHREM及びTEM-EDSを用いて検証したところ、界面は原子レベルで連続であり、明暗相間でY^<3+>イオン濃度の連続的な変化がおこっていることが明らかとなった。また、熱処理時間の増大とともに、Y^<3+>の濃度揺らぎが大きくなる様子もTEM-EDS分析により捉えられた。これらの実験結果はシミュレーション結果と良い一致を示している。このように、理論・実験両面からこの組織がスピノーダル分解によって生じた変調構造組織であることが示され、c-t相転移のモデリングの妥当性が示された。微細組織形成シミュレーションから、t-ZrO_2単相域内で等温熱処理を施すと、APBに溶質イオンであるY^<3+>が偏析することが予期された。APBへのY^<3+>の偏析は実験的にもZrO_2-Y_2O_3-TiO_2系で確認された。このようなAPBへの偏析現象の起源はAPBがc-ZrO_2に近い構造を取るためであり、c相安定化効果のあるイオンが偏析することで不安定なAPBを緩和していると解釈することができる。ZrO_2-CeO_2系で同様のt-ZrO_2単相域での組織発展の実験を行ったところ、Ce^<4+>はc相安定化効果のあるイオンであるにもかかわらず偏析していなかった。このAPBに対しTEM-EELS分析を行ったところ、APB上とドメイン内部ではCeイオンの電子状態が変化している様子が捉えられた。この変化は価数変化に起因すると考えられ、APB直上においてドメイン内部よりも価数が小さくなっでいる可能性が示された。DV-Xα法を用いた第一原理計算からもCe^<3+>がCe^<4+>4よりも格段に大きなc相安定化効果を持つという結果が得られており、このAPBはCeイオンの価数変化により偏析することなく安定化されている可能性がある。
ジルコニヤの相転移に伴う組織形成のコンピュータシミュレーション

幾原雄一, 佐久間健人

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特定領域研究(A)

Category: 特定領域研究(A)

Institution: 東京大学

1998 - 1998

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本研究では、コンピュータシミュレーションを用いて、ジルコニアセラミックスのc-t相転移に伴う微細組織形成に関する解析を行った。また第一原理的手法を用いて、c-ZrO_2安定化に関する解析も行った。 ZrO_2-Y_2O_3系のc-t相分離初期段階で観察される周期的な層状組織に対して、サブナノレベルのブローブを有する分析電子顕微鏡を用いて化学分析を行った。その結果、各ラメラ間でYイオン濃度が異なっており、電子顕微鏡像のコントラストと対応していることが明らかとなった。また、相分離の進行に伴いYイオン濃度の振幅が増加することも明らかとなった。さらにラメラ間でのYイオン濃度の変化を詳細に調べると、ラメラ界面でYイオン濃度が連続的に変化していることも実験的に示された。これは、これまでのコンピュータシミュレーションにより示された結果とよく合致するものである。また、このような組織の特徴は、この層状組織がスピノーダル分解に起因する変調構造であると考えることにより合理的に説明されうるものである。すなわち、ZrO_2-Y_2O_3系のc-t相分離はスピノーダル分解を伴うものであり、これはジルコニアのc-t無拡散相転移が二次相転移的な性質を有しているという考えを支持するものである。またc-ZrO_2およびt-ZrO_2に対してDV-Xα分子軌道法による計算を行ったところ、結晶中の隣接酸素イオン間の干渉と構造の安定性が密接に関連にしていることが明らかとなった。また同様の計算により、c-ZrO_2の安定化には、大きなイオン半径を有する陽イオンの添加と酸素イオン空孔の導入が有効であることも明らかとなった。
Atomic and Electronic Structure of Ceramic Bicrystals and High Temperature Strength

IKUHARA Yuichi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: The University of Tokyo

1997 - 1998

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Mechanical properties of ceramics are closely related to the atomic structure and chemical bonding state in the grain boundaries. Therefore, the relationships between properties and grain boundary structure are needed to be clarified in order to obtain a guideline to design high strength and high reliable ceramics. In this study, 1 : Fabrication of ceramics bicrystals, 2 : Evaluation of grain boundary atomic and electronic structure, 3 : Grain boundary characteristics and grain boundary sliding, and 4 : Effect of grain boundary segregation were systematically investigated and the following results were obtained. 1 : Fabrication of ceramics Zirconia bicrystals with [110] tilt boundaries and alumina bicrystals with [1120] tilt boundaries were fabricated by joining two single crystals at high temperatures. Their grain boundary energy was measured by observing the profiles of thermal grooving by an atomic force microscope. It was found that the grain boundary energy depends on the grain boundary characteristics and shows the energy cusp at the tilt angles corresponding to CSL orientation. 2 : Evaluation of grain boundary atomic and electronic structure Grain boundary atomic structures in the bicrystals were determined by combing HREM image and the image simulation technique. The obtained structures were compared with the atomic structures deduced by molecular orbital method. The experimental results agreed well with the theoretically obtained structures. 3 : Grain boundary characteristics and grain boundary sliding It was found that the grain boundary sliding were influenced by the grain boundary characteristics. However, grain boundary sliding is mainly controlled by the grain boundary atomistic configuration, rather than grain boundary energy. 4 : Effect of grain boundary segregation Grain boundary segregation was investigated by EDS and EELS by using nano probe in a field emission electron microscope. It was found that the chemical composition and chemical bonding state in the segregation strongly depended on the grain boundary characteristics. Grain boundary chemical bonding state was evaluated by comparing the EELS spectra and partial density of state calculated by the molecular orbital method.
ジルコニアの相転移に伴う微細組織形式のコンピュータシミュレーション

幾原雄一, 佐久間健人

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 重点領域研究

Institution: 東京大学

1997 - 1997

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本研究では、ジルコニアセラミックスのc-t相転移に伴う微細組織形成に対して、コンピュータシミュレーションを中心とした解析を行った。シミュレーションは、c-t相転移を二次転移と仮定したモデルを用い、time-dependent Ginzburg-Landau(TDGL)方程式の解を算出することにより行った。このシミュレーション結果は、ZrO_<2->Y_2O_3系で観察されるドメイン構造や、層状の変調構造等の特異な組織をよく再現しており、実際の現象の評価に有用なものであることが示唆される。同様の手法により、実験的に困難であるt-ZrO_2単相領域での熱処理のシミュレーションを行ったところ、ドメイン構造の逆位相境界(APB)にY^<3+>イオンが偏析する傾向にあることが明らかになった。またAPBは、c-ZrO_2あるいはそれに近い構造を有しているものとして計算された。このことから、c-ZrO_2安定化効果のあるY^<3+>イオンがAPBの構造を安定化させるために偏析したものと考えることができる。このようなAPBへのY^<3+>イオンの偏析は、比較的広いt-ZrO_2単相領域を有するZrO_2-Y_2O_3-TiO_2系セラミックスのFE‐TEMによる実験結果とも符合した。また、ZrO_2-R_2O_3(R:希土類酸化物)系のc-t相分離をシミュレートした結果、より大ききなR^<3+>を添加した系の方が相分離速度が上昇する傾向にあることが示された。このような相分離速度の差異が組織形成に大きな影響を与えることは実験的にも報告されており、本研究によるシミュレーションと合致するものとなっている。
セラミックス焼結過程の高分解能その場観察技術の開発

幾原雄一

Offer Organization: 日本学術振興会

System: 科学研究費助成事業萌芽的研究

Category: 萌芽的研究

Institution: 東京大学

1997 - 1997

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セラミックス材料の焼結や粒成長などの高温における素過程については、未だ多くのことが明確になっていない。本研究では、高温TEMその場観察法と高分解能電子顕微鏡法を組み合わせて、セラミックスの高温現象の素過程を動的に明らかにすることを目的としている。まず、TEM-CCDカメラとビデオシステムをTEM本体に組み込み、高温加熱ステージの高温安定性および温度補正法について検討し、その場観察の最適条件を見出した。次に、粉末試料を高温で安定に保持するための支持体の材質・形状を検討した結果、Ta製穴あきディスクあるいはW製ワイヤーが優れていることが分かった。以上の実験条件の検討を基に、ジルコニアとアルミナ粉末の高温その場実験を実施した。その際、各試料の状態を室温から1600℃まで連続的に観察し、記録はビデオシステムを用いて行った。ジルコニア、アルミナともに連続的に粒成長・合体していく様子が明瞭に観察された。ジルコニアでは表面の数原子層が集団で運動する過程が観察されたが、これは表面拡散に対応するものと考えられる。また、ジルコニアに微量のシリカを添加した系についての高温観察も行った。その結果、約1000℃でジルコニアとシリカは反応し、大部のシリカはジルコニア中に固溶して消失する現象が観察された。この試料を冷却すると約600℃でジルコニア粉末表面からシリカ膜の析出が観察された。従来ジルコニアとアルミナは固溶しない系とされてきたが、今回の結果はジルコニアの極表面部においてシリカは固溶可能であることを示唆している。この結果は、シリカ添加ジルコニアの粒界において数nmのSi偏析相が存在するという高分解能観察・EDS分析の結果と一致する。また、粒界のEELS測定とSiの固溶をモデルとした分子軌道法の計算結果の比較もSiがジルコニア中に固溶していることを示した。以上のように、本手法によって、従来は不明であった幾つかのセラミックスの高温現象の素過程が明らかになった。今後、本手法をさらに種々の系に適用していくことによって、多くの不明確な高温現象が解明されることが期待される。

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