| Project/Area Number |
13450259
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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 |
Physical properties of metals
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| Research Institution | Toyohashi University of Technology |
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Principal Investigator |
KAMEGASHIRA Naoki Toyohashi University of Technology, Materials Science, Professor, 工学部, 教授 (20023153)
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| Co-Investigator(Kenkyū-buntansha) |
SATOH Hirohisa Toyohashi University of Technology, Materials Science, Assistant, 工学部, 助手 (10215832)
NAKANO Hiromi Ryukoku Universtity, Electron Microscope Laboratory, Lecturer, 理工学部・電子顕微鏡室, 実験講師 (00319500)
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| Project Period (FY) |
2001 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥14,900,000 (Direct Cost: ¥14,900,000)
Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2003: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2002: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2001: ¥9,800,000 (Direct Cost: ¥9,800,000)
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| Keywords | rare earth manganites / new materials / subsequent phase transition / magnetism / single crystals / 相解析 / 結晶構造 / 層状ペロブスカイト / 相転移 / 新物質合成 / 多形 / 単結晶構造解析 / 単結晶育成 / ペロブスカイト / 熱測定 / 磁気的性質 / 層状構造 |
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| Research Abstract |
This project was aimed to develop new materials for four years with various types of magnetism and phase transition on the basis of rare earth manganites which have been studied for many years by the authors. The unique point of this project is application of adjustment technique of oxygen partial pressure to control valence state of manganese, which affects magnetic interaction and phase transition based on the tilting model of oxygen octahedra of the crystal structures. Our group has established this unique technique. Several new materials of Ln_2MnTiO_6(Ln=rare earth) were successfully synthesized under low oxygen partial pressure at high temperature. These have three kinds of crystal structures and unique magnetic interaction between long distant ions. Another new materials of rare earth manganites containing precious metal elements with perovskite structure were also developed, which have phase transition at high temperature and magnetism from a combination of antiferromagnetic an
… More
d ferromagnetic interactions between magnetic ions. New types of phase transition were further discovered for some rare earth manganites with layered perovskites such as BaLn_2Mn_2O_7 and (Ca,Ln)_2MnO_4 (Ln=rare earth) at high and low temperature. These phase transitions were characterized by tilting model of mutual oxygen octahedra inside the structure from the results of high and low temperature X-ray diffractometry and electron diffraction analysis and high resolution electron microscopic study. Single crystal characterization method became useful to clarify phase behavior in this project after annealing single crystal under various heat treatment conditions for refinement to determine the crystal structures. Other types of new materials with pyrochlore-related structure were also successfully synthesized and their crystal structures were characterized by several methods as mentioned above. Thus new results were obtained from this project and these results are now published in international academic journals. Less
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