Details of the Researcher

PHOTO

Kazutoshi Inoue
Section
Advanced Institute for Materials Research
Job title
Associate Professor
Degree

  • 博士（理学）（東北大学）

  • 修士（理学）（東北大学）

Professional Memberships 3

  • 日本物理学会

  • 日本数学会

  • THE JAPAN INSTITUTE OF METALS AND MATERIALS

Research Interests 3

  • interface

  • crystallography

  • grain boundary

Research Areas 1

  • Nanotechnology/Materials / Metallic materials /

Awards 1

  1. Paper Award

    2019/06

Papers 32

  1. Enhanced ferromagnetism in an artificially stretched lattice in quasi-two-dimensional Cr2Ge2Te6

    Hiroshi Idzuchi, Andres E. Llacsahuanga Allcca, Anh Khoa Augustin Lu, Mitsuhiro Saito, Subhadip Das, John F. Ribeiro, Michel Houssa, Ruishen Meng, Kazutoshi Inoue, Xing-Chen Pan, Katsumi Tanigaki, Yuichi Ikuhara, Takeshi Nakanishi, Yong P. Chen

    Physical Review B　2025/01/07

    DOI： 10.1103/PhysRevB.111.L020402 　

  2. Reduction of (100)-Faceted CeO2 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　2024/05/21

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acs.chemmater.4c00627 　

    ISSN： 0897-4756

    eISSN： 1520-5002

  3. 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　2024

    DOI： 10.1021/acsnano.4c01475 　

    ISSN： 1936-0851

    eISSN： 1936-086X

  4. Prominent Structural Dependence of Quantum Capacitance Unraveled by Nitrogen‐Doped Graphene Mesosponge

    Rui Tang, Alex Aziz, Wei Yu, Zheng‐Ze Pan, Ginga Nishikawa, Takeharu Yoshii, Keita Nomura, Erin E. Taylor, Nicholas P. Stadie, Kazutoshi Inoue, Motoko Kotani, Takashi Kyotani, Hirotomo Nishihara

    Small　2023/12/06

    Publisher: Wiley

    DOI： 10.1002/smll.202308066 　

    ISSN： 1613-6810

    eISSN： 1613-6829

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    Abstract Porous carbons are important electrode materials for supercapacitors. One of the challenges associated with supercapacitors is improving their energy density without relying on pseudocapacitance, which is based on fast redox reactions that often shorten device lifetimes. A possible solution involves achieving high total capacitance (Ctot), which comprises Helmholtz capacitance (CH) and possibly quantum capacitance (CQ), in high‐surface carbon materials comprising minimally stacked graphene walls. In this work, a templating method is used to synthesize 3D mesoporous graphenes with largely identical pore structures (≈2100 m2 g−1 with an average pore size of ≈7 nm) but different concentrations of oxygen‐containing functional groups (0.3–6.7 wt.%) and nitrogen dopants (0.1–4.5 wt.%). Thus, the impact of the heteroatom functionalities on Ctot is systematically investigated in an organic electrolyte excluding the effect of pore structures. It is found that heteroatom functionalities determine Ctot, resulting in the cyclic voltammetry curves being rectangular or butterfly‐shaped. The nitrogen functionalities are found to significantly enhance Ctot owing to increased CQ.

  5. Edge‐Site‐Free and Topological‐Defect‐Rich Carbon Cathode for High‐Performance Lithium‐Oxygen Batteries International-journal

    Wei Yu, Takeharu Yoshii, Alex Aziz, Rui Tang, Zheng‐Ze Pan, Kazutoshi Inoue, Motoko Kotani, Hideki Tanaka, Eva Scholtzová, Daniel Tunega, Yuta Nishina, Kiho Nishioka, Shuji Nakanishi, Yi Zhou, Osamu Terasaki, Hirotomo Nishihara

    Advanced Science　10　(16)　e2300268　2023/04/07

    Publisher: Wiley

    DOI： 10.1002/advs.202300268 　

    ISSN： 2198-3844

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    The rational design of a stable and catalytic carbon cathode is crucial for the development of rechargeable lithium-oxygen (LiO2 ) batteries. An edge-site-free and topological-defect-rich graphene-based material is proposed as a pure carbon cathode that drastically improves LiO2 battery performance, even in the absence of extra catalysts and mediators. The proposed graphene-based material is synthesized using the advanced template technique coupled with high-temperature annealing at 1800 °C. The material possesses an edge-site-free framework and mesoporosity, which is crucial to achieve excellent electrochemical stability and an ultra-large capacity (>6700 mAh g-1 ). Moreover, both experimental and theoretical structural characterization demonstrates the presence of a significant number of topological defects, which are non-hexagonal carbon rings in the graphene framework. In situ isotopic electrochemical mass spectrometry and theoretical calculations reveal the unique catalysis of topological defects in the formation of amorphous Li2 O2 , which may be decomposed at low potential (∼ 3.6 V versus Li/Li+ ) and leads to improved cycle performance. Furthermore, a flexible electrode sheet that excludes organic binders exhibits an extremely long lifetime of up to 307 cycles (>1535 h), in the absence of solid or soluble catalysts. These findings may be used to design robust carbon cathodes for LiO2 batteries.

  6. 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.

  7. Capacitance of edge-free three-dimensional graphene: New perspectives on the design of carbon structures for supercapacitor applications

    Rui Tang, Keita Nomura, Kazutoshi Inoue, Motoko Kotani, Takashi Kyotani, Hirotomo Nishihara

    Electrochimica Acta　429　2022/10/10

    DOI： 10.1016/j.electacta.2022.141009 　

    ISSN： 0013-4686

  8. 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

  9. 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　2021/06/21

    Publisher: Royal Society of Chemistry (RSC)

    DOI： 10.1039/d1nr01746b 　

    ISSN： 2040-3364

    eISSN： 2040-3372

  10. Arrangement of polyhedral units for [0001]-symmetrical tilt grain boundaries in zinc oxide

    Kazutoshi Inoue, Ji Young Roh, Kazuaki Kawahara, Mitsuhiro Saito, Motoko Kotani, Yuichi Ikuhara

    Acta Materialia　212　2021/06/15

    DOI： 10.1016/j.actamat.2021.116864 　

    ISSN： 1359-6454

  11. Anataselike Grain Boundary Structure in Rutile Titanium Dioxide

    Georg Schusteritsch, Ryo Ishikawa, Abdul Razak Elmaslmane, Kazutoshi Inoue, Keith P. McKenna, Yuichi Ikuhara, Chris J. Pickard

    Nano Letters　21　(7)　2745-2751　2021/04

    DOI： 10.1021/acs.nanolett.0c04564 　

    ISSN： 1530-6984

    eISSN： 1530-6992

  12. Atomistic origin of high-concentration Ce3+ in {100}-faceted Cr-substituted CeO<inf>2</inf> nanocrystals Peer-reviewed

    Xiaodong Hao, Akira Yoko, Kazutoshi Inoue, Yang Xu, Mitsuhiro Saito, Chunlin Chen, Gimyeong Seong, Takaaki Tomai, Seiichi Takami, Alexander L. Shluger, Bingshe Xu, Tadafumi Adschiri, Yuichi Ikuhara

    Acta Materialia　203　2021/01/15

    Publisher: Elsevier BV

    DOI： 10.1016/j.actamat.2020.11.015 　

    ISSN： 1359-6454

  13. 3D arrangement of atomic polyhedra in tilt grain boundaries Peer-reviewed

    Kazutoshi Inoue, Kazuaki Kawahara, Mitsuhiro Saito, Motoko Kotani, Yuichi Ikuhara

    Acta Materialia　202　(1)　266-276　2021/01/01

    Publisher: Elsevier BV

    DOI： 10.1016/j.actamat.2020.10.017 　

    ISSN： 1359-6454

  14. Analysis of the hierarchy of grain-boundary structural units Peer-reviewed

    Kazutoshi Inoue, Mitsuhiro Saito, Kazuaki Kawahara, Motoko Kotani, Yuichi Ikuhara

    Math-for-Industory Research　15　67-74　2019/11

  15. Strong metal–metal interaction and bonding nature in metal/oxide interfaces with large mismatches Peer-reviewed

    Hongping Li, Mitsuhiro Saito, Chunlin Chen, Kazutoshi Inoue, Kazuto Akagi, Yuichi Ikuhara

    Acta Materialia　179　237-246　2019/10/15

    DOI： 10.1016/j.actamat.2019.08.018 　

    ISSN： 1359-6454

  16. Nanodomain Structures in a Strained Batio3 Film Detected Using Picoscale Cation Displacement Measurements Peer-reviewed

    S. Kobayashi, K. Inoue, T. Kato, Y. Ikuhara, T. Yamamoto

    AMTC Letters　6　10-11　2019/06

  17. 新たな原子構造をもつ第四の固体物質 ー 周期性と非周期性が共存する一次元規則結晶の発見 Peer-reviewed

    井上和俊, 斎藤光浩, 幾原雄一

    化学　74　(7)　12-15　2019/06

  18. Determination of the structure and properties of an edge dislocation in rutile TiO<inf>2</inf> Peer-reviewed

    Emile Maras, Mitsuhiro Saito, Kazutoshi Inoue, Hannes Jónsson, Yuichi Ikuhara, Keith P. McKenna

    Acta Materialia　163　199-207　2019/01/15

    DOI： 10.1016/j.actamat.2018.10.015 　

    ISSN： 1359-6454

  19. Ceramic phases with one-dimensional long-range order Peer-reviewed

    Deqiang Yin, Chunlin Chen, Mitsuhiro Saito, Kazutoshi Inoue, Yuichi Ikuhara

    Nature Materials　18　(1)　19-23　2019/01/01

    DOI： 10.1038/s41563-018-0240-0 　

    ISSN： 1476-1122

    eISSN： 1476-4660

  20. Atomic-Scale Valence State Distribution inside Ultrafine CeO<inf>2</inf> Nanocubes and Its Size Dependence Peer-reviewed

    Xiaodong Hao, Akira Yoko, Chunlin Chen, Kazutoshi Inoue, Mitsuhiro Saito, Gimyeong Seong, Seiichi Takami, Tadafumi Adschiri, Yuichi Ikuhara

    Small　14　(42)　2018/10/18

    DOI： 10.1002/smll.201802915 　

    ISSN： 1613-6810

    eISSN： 1613-6829

  21. Direct Imaging for Single Molecular Chain of Surfactant on CeO<inf>2</inf> Nanocrystals Peer-reviewed

    Xiaodong Hao, Chunlin Chen, Mitsuhiro Saito, Deqiang Yin, Kazutoshi Inoue, Seiichi Takami, Tadafumi Adschiri, Yuichi Ikuhara

    Small　14　(31)　2018/08/02

    DOI： 10.1002/smll.201801093 　

    ISSN： 1613-6810

    eISSN： 1613-6829

  22. Direct Determination of Atomic Structure and Magnetic Coupling of Magnetite Twin Boundaries Peer-reviewed

    Chunlin Chen, Hongping Li, Takehito Seki, Deqiang Yin, Gabriel Sanchez-Santolino, Kazutoshi Inoue, Naoya Shibata, Yuichi Ikuhara

    ACS Nano　12　(3)　2662-2668　2018/03/27

    DOI： 10.1021/acsnano.7b08802 　

    ISSN： 1936-0851

    eISSN： 1936-086X

  23. Multiphase nanodomains in a strained BaTiO<inf>3</inf> film on a GdScO<inf>3</inf> 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： 0021-8979

    eISSN： 1089-7550

  24. 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： 1936-0851

    eISSN： 1936-086X

  25. Structure of Tilt Grain Boundaries from Mathematical Perspective Peer-reviewed

    Kazutoshi Inoue, Motoko Kotani, Yuichi Ikuhara

    九州大学マス・フォア・インダストリ研究所レクチャーノート　2017/12

  26. Analysis of Periodic Atomic Structures in Grain Boundaries by Number Theory Peer-reviewed

    Inoue Kazutoshi, Saito Mitsuhiro, Kotani Motoko, Ikuhara Yuichi

    Materia Japan　56　(10)　589-596　2017/10

    Publisher: The Japan Institute of Metals and Materials

    DOI： 10.2320/materia.56.589 　

    ISSN： 1340-2625

  27. 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

  28. 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　2016/12/01

    DOI： 10.1093/jmicro/dfw034 　

    ISSN： 2050-5698

    eISSN： 2050-5701

  29. 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　2016/02/18

    DOI： 10.1038/srep21273 　

    ISSN： 2045-2322

    eISSN： 2045-2322

  30. - Peer-reviewed

    Kazutoshi Inoue, Chunlin Chen, Motoko Kotani, Yuichi Ikuhara

    まてりあ　55　(12)　582-582　2016

    Publisher: The Japan Institute of Metals and Materials

    DOI： 10.2320/materia.55.582 　

  31. 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

  32. 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

    DOI： 10.2320/matertrans.M2015277 　

    ISSN： 1345-9678

    eISSN： 1347-5320

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Research Projects 4

  1. マルチスケール粒界理論の構築による新材料開拓

    井上 和俊

    Offer Organization: 科学技術振興機構

    System: 戦略的な研究開発の推進 創発的研究支援事業

    Institution: 東北大学

    2022 - 2028

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    結晶同士の界面である粒界の原子構造と機能特性との間には、深い相関性があります。本研究では、幾何学および整数論に基づく原子論的アプローチにより、すべての粒界構造を普遍的に記述する理論を完成させ、原子構造予測を効率化します。さらに、微分幾何学に基づくメソスケール粒界理論の構築により、多結晶体の機能予測に挑みます。そして双方の粒界理論を統合し、粒界構造を制御した材料設計指針の確立に貢献します。

  2. 粒界数理学の構築に基づく機能材料創出

    井上 和俊

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業 基盤研究(B)

    Category: 基盤研究(B)

    Institution: 東北大学

    2021/04/01 - 2025/03/31

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    金属・酸化物等から構成される機能材料は多結晶体として用いられ, 種々の格子欠陥が材料の機能特性に多大な影響を及ぼすことが知られている. 特に粒界構造を系統的に記述することは重要であるが, 傾角粒界近傍の原子構造は従来二次元構造ユニット配列で記述されてきた. 一方, 結晶の三次元構造は特定の多面体によって充填されることが知られているが, 粒界近傍を充填する場合, 母結晶の多面体を歪ませた多面体の他に, 粒界由来の多面体が存在する. 本研究では, 面心立方金属の[001]傾角・捩り粒界の幾何学モデル, および粒間並進モデルを系統的に構築し, 第一原理計算により各構造の粒界エネルギーを求めた. また, 剛体球充填モデルを採用し, 原子位置についてのボロノイ分割に基づき, 各ボロノイ頂点に挿入しうる球の最大半径(ボイド半径)を求めた. 各構造における最大のボイド半径と最安定構造の粒界エネルギーを比較した結果, それらがよく相関することが分かった. 剛体並進により系全体のボイドサイズを平均化し, さらに局所的に原子位置を最適化すること最安定構造が得られることが推測される. また, 対応方位関係は回転軸と回転角を与えることによって決定するが, 異なる回転軸・回転角から同 一の粒界を構成できる場合があるため既存の分類法では重複が生じる. 本研究では, 整数論的手法を用いて対応方位関係における整合結晶面を決定することで, 任意の対応粒界に適用出来る粒界分類法を構築した.

  3. 離散・位相幾何学的手法による界面構造予測と粒界指標の確立

    井上 和俊

    Offer Organization: 科学技術振興機構

    System: 戦略的な研究開発の推進 戦略的創造研究推進事業 さきがけ

    Institution: 東北大学

    2017 - 2020

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    離散および位相幾何学的手法を基軸とした純粋数学的手法と,原子分解能走査透過電子顕微鏡法・第一原理計算の融合により, 粒界現象の背後に潜む数理構造を抽出します.これにより,安定粒界構造および粒界現象の根本原理を解明し,既存の粒界幾何学理論を超えた新たな粒界原子構造の幾何学を構築します.そして機能予測に有効な粒界構造指標を提案し,多結晶体の機能特性の系統的予測に取り組みます.

  4. 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

    2015/04/01 - 2018/03/31

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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.