1997 Fiscal Year Final Research Report Summary
Role of anions and chemical bond in the metallic inorganic compounds
| Project/Area Number |
07404054
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
機能・物性・材料
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
KOSUGE Koji Kyoto Univ., Graduate School of Sci., Prof., 大学院・理学研究科, 教授 (00025371)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Masaki Kyoto Univ., Graduate School of Sci., Instructor, 大学院・理学研究科, 助手 (90271006)
YOSHIMURA Kazuyoshi Kyoto Univ., Graduate School of Sci., Asso.Prof., 大学院・理学研究科, 助教授 (70191640)
OKA Yoshio Kyoto Univ., Integrated Human Studies, Prof., 総合人間学部, 教授 (10152282)
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| Project Period (FY) |
1995 – 1997
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| Keywords | vabadium chalcogenides / chamical transport / nuclear magnetic resonance / CaRuO_3 / SrRuO_3 / Invar effect |
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| Research Abstract |
(A)Investigation of vanadium chalcogenides
(1)We tried to grow the single crystals of vanadium chalcogenides V_3X_4, V_5X_8 (X=S,Se) by a chemical transport methods using of TeCl_2, I_2, HCl and Cl_2 as transport agents.
The infrared arc furnace was used for these experiment. As a result, it was confirmed that I_2 as a transport agent is most adequate to get a larger good single crystal. For example, we got a single crystal of V_5S_8 with the dimension 5*5*1mm.
(2)Measurement of magnetizatio process of V_5S_8 single crystal was done under the high magnetic field up to 50T,which showed two step magnetization. The paper on this experiment with the detailed discussion is now contributing.
(3)And also NMR (nuclear magnetic resonance) measurement on ^<51>V of V_5S_8 is under investigation
(B)Investigation of (Sr_<1-x>Ca_x) RuO_3 with the perovskite structure.
Both of CaRuO_3 and SrRuO_3 have the perovskite-type structure and show a metallic behavior. The former is paramagnetic down to 1.2K and the latter shows a phase transtition to ferromagnetic at 150K.The characteristics of the solid solution (Sr_<1-x>Ca_x) RuO_3 is in the behavior of thermal expansion (sigma). The sigma of CaRuO_3 can ve fitted by a Debye function. On the other hand, the sigma of SrRuO_3 ahows "Invar effect" below T_c, that is, independent on temperature. This is a first discovery of Invar Oxides, which may be closely related to electron correlation. The paper has been published in Phys. Rev.B.
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