| Project/Area Number |
15360340
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
YASHIMA Masatomo Tokyo Institute of Technology, Interdisciplinary Graduate School of Science and Engineering, Associate Professor, 大学院・総合理工学研究科, 助教授 (00239740)
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| Co-Investigator(Kenkyū-buntansha) |
IZUMI Fujio Tokyo Institute of Technology, Materials and Structures Laboratory, Professor, 物質研究所, 主席研究員 (70354397)
SASAKI Satoshi National Institute for Materials Science, Advanced Material Institute, Senior Researcher, 応用セラミックス研究所, 教授 (10162364)
KAMIYAMA Takeshi High Energy Accelerator Research Organization, Institute for Materials Structure Science, Associate Professor, 物質構造科学研究所, 助教授 (60194982)
TANAKA Masahiko High Energy Accelerator Research Organization, Institute for Materials Structure Science, Research Associate, 物質構造科学研究所, 助手 (60249901)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥13,400,000 (Direct Cost: ¥13,400,000)
Fiscal Year 2004: ¥5,300,000 (Direct Cost: ¥5,300,000)
Fiscal Year 2003: ¥8,100,000 (Direct Cost: ¥8,100,000)
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| Keywords | positional disorder / diffusion path / oxide-ion conductors / Rietveld refinement / maximum-entropy method / perovskite / fluorite-type structure / synchrotron / 中性子回折 / イオン伝導経路 / 放射光粉末回折 / 電子密度分布 |
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| Research Abstract |
We have investigated the positional disorder and diffusion path of oxide ions in Bi_2O_3,CeO_2, and (La_<0.8>Sr_<0.2>)(Ga_<0.8>Mg_<0.15>Co_<0.05>)O_<3-δ・>. These were studied through the nuclear density distribution obtained by a combined technique including a Rietveld refinement, a maximum-entropy method(MEM) and MEM-based pattern fitting of the neutron powder diffraction data measured at high temperatures. Oxide ions in fluorite-type structured δ-Bi_2O_3 and CeO_2 have a complicated disorder spreading over a wide area and shift to the <111> directions from the ideal fluorite site at higher temperatures. Diffusion path of oxide ions in (La_<0.8>Sr_<0.2>)(Ga_<0.8>Mg_<0.05>Co_<0.05>)O_<3-δ> perovskite is not along the straight line between the ideal positions, but exhibits an arc shape away from the B-site cation (Ga_<0.8>Mg_<0.5>Co_<0.05>).
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