MESSAGE
Nagoya University)
“CRYSTAL DEFECT CORE” PROJECT HAS LAUNCHED!
Since occurrence of the human civilization, epoch-making innovations in fields of environmental conservation, energy development and information technology have been realized by emergence of novel and advanced materials of metals, ceramics, and semiconductors. In this regard, it is not too much to say that materials science has played an essential role for them in history of mankind. In the current complicated, diversified and globalized modern societies, however, timely development of unprecedented materials is indispensable and highly desired. Therefore, it is necessary to conduct materials development based on a new concept in materials science.
In this project, we firmly conduct fundamental and scientific researches on the structure property relationships in crystal defects of materials at the nanometer scale. This is because crystal defects such as grain boundaries, interfaces and dislocations are found to become physical origins of distinct properties in recent advanced materials. Moreover, scientific attempts are now being done in advanced-material development by designing and controlling physical properties of crystal defects at the nanometer scale. If we know how to maximize potentials of physical properties of crystal defects, such knowledge should provide us with breakthroughs in materials science. Then, it should be an indispensable step to systematically reveal nature of specific electronic and atomic structures at crystal defects, especially at their core regions.
Here we refer to specific electronic and atomic structures localized at crystal defects as “crystal defect cores”, and try to establish the new materials science. For this purpose, researchers specializing in theoretical calculations, nanoscale characterization and advanced materials processing conduct collaborative studies. Establishment of new scientific principles based on the concept of “crystal defect core” will make it possible to explore novel materials with excellent properties due to crystal defects.
RESEARCH
PURPOSE OF THE RESEARCH PROJECT
In this project, specific electronic and atomic structures of grain boundaries, interfaces and dislocations that can realize novel and distinct materials properties are defined and referred to as “crystal defect cores”. Researchers specializing in theoretical calculations, nanoscale characterization and advanced materials processing conduct collaborative studies, aiming at creating a new area in materials science named “crystal defect core”. Through establishing new scientific principles based on the concepts of “crystal defect core”, we will further explore novel properties and materials due to crystal defects.
Conventional studies have focused on average bulk structures and macroscopic properties of materials in general, and thus understanding of crystal defects is often limited to their static and averaged atomic pictures. Recent technological progresses in methods and approaches of nanoscale characterization and computational science are so remarkable that we have been enabled to acquire quantitative information on nanoscale structures of crystal defects. These advanced approaches and methods have facilitated our more in-depth understanding about the crucial roles that the crystal defects play for realizing various materials properties. For future materials design and development, it is essential to reveal relationships between nanoscale structures of crystal defects and materials properties. Thus, in this project, we aim at discovering or creating new materials functions and new exploratory materials based on “crystal defect cores”, including those emerging under external stimulus including thermal, electric, magnetic, optical or stress fields.
CONTENT OF THE RESEARCH PROJECT
This research project has three major research items as follows:
- A01: Modeling and design of crystal defect cores
- A02: Nanoscale characterization of crystal defect cores
- A03: Materials development based on crystal defect cores
In research items A01 and A02, we focus on basic science of crystal defects. We do collaborative and systematic researches of grain boundaries, interfaces and dislocations so as to establish new scientific principles based on in-depth understanding of a structure-property relationship of the crystal defects, by means of theoretical calculations, materials informatics and nanoscale characterization at the world-class highest level. Researches in the Research item A03 of materials processing come from diverse materials fields, and try to develop novel materials and their properties by controlling crystal defects at the nanometer scale. Throughout the research area, it is expected for our intensive and extensive collaborations to prove that “crystal defect core” is a universal concept to realize novel materials development in the next generation.
EXPECTED RESEARCH ACHIEVEMENTS
- To establish new scientific principles to make it possible to explore novel and distinct materials properties originating from crystal defects
- To discover or create new materials with remarkable properties in diverse fields of materials science
- To facilitate considerable technical development of theoretical calculations, nanoscale characterization, and materials processing
EXPECTED SCIENTIFIC SIGNIFICANCE
Our concept of “crystal defect core” will provide a scientific impact when we succeed in developing materials and their properties through precisely controlling crystal defect cores. This is because crystal defects have been thought to play a negative role for materials properties. This research area can find out a new strategy for controlling crystal defect cores so that they play positive roles for better properties, paving a new avenue for future materials developments.
MEMBER
EXECUTIVE COMMITTEE
| Katsuyuki Matsunaga (Nagoya University) | Teruyasu Mizoguchi (The University of Tokyo) |
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| Naoya Shibata (The University of Tokyo) | Masayuki Abe (Osaka University) |
| Hitoshi Yusa (National Institute for Materials Science) | Hiromichi Ohta (Hokkaido University) |
| Satoshi Kitaoka (Japan Fine Ceramics Center) | Masaaki Hirayama (Tokyo Institute of Technology) |
| Masato Yoshiya (Osaka University) | Atsutomo Nakamura (Osaka University) |
| Hidehiro Yoshida (The University of Tokyo) | |
EVALUATION COMMITTEE MEMBERS
| Taketo Sakuma (The University of Tokyo, Emeritus Professor) |
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| Hirotarou Mori (Osaka University, Invited Professor) |
| Seizo Morita (Osaka University, Emeritus Professor) |
| Masanori Kohyama (National Institute of Advanced Industrial Science and Technology, Emeritus Researcher) |
RESEARCH AREA ADVISORS
| Isao Tanaka (Kyoto University, Professor) |
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| Yuichi Ikuhara (The University of Tokyo, Professor) |
EXTERNAL EXAMINER
| Toshiki Sugimoto (Institute for Molecular Science, Associate Professor) |
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| Yuichi Yoshida (National Institute of Informatics, Associate Professor) |
RESEARCH ITEMS AND GROUPS
A01Modeling and Design of Crystal Defect Cores
A01-aModeling of Crystal Defect Cores
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A01-bComputational Design with Materials Informatics
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A02Nanoscale Characterization of Crystal Defect Cores
A02-cNanoscale Interface Characterization
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A02-dNanoscale Surface Characterization
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A03Materials Development Based on Crystal Defect Cores
A03-eFunctional Materials with High Temperature/Pressure Processing
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A03-fThermoelectric Materials with Thin Film Processing
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A03-gHigh-Temperature Structural Ceramics
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A03-hSolid State Ionic Materials
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ACHIEVEMENT
2021.12.21
T. Yokoi, K. Adachi, S. Iwase, K. Matsunaga, Accurate prediction of grain boundary structures and energetics in CdTe: A machine-learning potential approach, Phys. Chem. Chem. Phys. (2021) accepted.2021.12.03
Hai Jun Cho*, Yuzhang Wu, Jiajun Qi, Yuna Kim, and Hiromichi Ohta, Osamu Matsuda*, “Specular acoustic vibrational wave transmissions with the presence of phononic bandgaps”, J. Phys. Soc. Japan 91, 014601 (2022). (DOI: 10.7566/JPSJ.91.014601)2021.11.27
第15回物性科学領域横断研究会 (領域合同研究会) 若手奨励賞
「計算科学と情報科学による粒界原子構造ー熱 伝導相関の解明」
藤井進2021.11.26
S. Fujii, K. Funai, T. Yokoi, M. Yoshiya, Grain-size dependence and anisotropy of nanoscale thermal transport in MgO, Appl. Phys. Lett., 119 (23), 231604(2021), Published Online. (https://doi.org/10.1063/5.0075854)2021.11.16
Yusuke Ogura, Tatsuya Yokoi, Kotaro Fujii, Masatomo Yashima, Katsuyuki Matsunaga, “Effect of La vacancies on the oxide-ion conduction in lanthanum silicate apatites”, Solid State Ionics 373 (2021) 115793, (https://doi.org/10.1016/j.ssi.2021.115793)2021.11.16
T. Ushiro, T. Yokoi, Y. Noda, E. Kamiyama, M. Ohbitsu, H. Nagakura, K. Sueoka, K. Matsunaga, Preferential Growth Mode of Large-Sized Vacancy Clusters in Silicon: A Neural-Network Potential and First-Principles Study, J. Phys. Chem. C, 125(48) (2021) 26869-26882. (DOI: 10.1021/acs.jpcc.1c07973)2021.11.11
Hiroaki Nakade, Eita Tochigi, Bin Feng, Ryo, Ishikawa, Hiromichi Ohta, Naoya Shibata, Yuichi Ikuhara, “Effect of annealing on grain growth and Y segregation behavior in tetragonal ZrO2 thin film”, J. Am. Ceram. Soc. XX, XXXX (2021). (DOI: 10.1111/jace.18217)2021.11.04
Xi Zhang*, Gowoon Kim, Qian Yang, Jiake Wei, Bin Feng, Yuichi Ikuhara, and Hiromichi Ohta*, “Solid-State Electrochemical Switch of Superconductor-Metal-Insulators”, ACS Applied Materials & Interfaces 13, 54204-54209 (2021). (DOI: 10.1021/acsami.1c17014)2021.11.02
Shun-ichiro Ito, Kaito Kanahashi, Hiromichi Ohta, Hiroshi Ito, Taishi Takenobu* and Hisaaki Tanaka*,
Structure and thermoelectric properties in electrochemically doped polythiophene thin films: effect of side chain density,
Appl. Phys. Lett. 119, 183304 (2021).(https://aip.scitation.org/doi/10.1063/5.0067769)2021.11.01
James A. Quirk, Bin Miao, Bin Feng, Gowoon Kim, Hiromichi Ohta, Yuichi Ikuhara, and Keith P. McKenna, “Unveiling the Electronic Structure of Grain Boundaries in Anatase with Electron Microscopy and First-Pronciples Modeling”, Nano Lett. 21, 9217-9223(2021). (DOI: 10.1021/acs.nanolett.1c03099)