| Project/Area Number |
16540319
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
IGA Fumitoshi Hiroshima University, Graduate School of advanced Sciences of Matter, Associate Professor, 大学院・先端物質科学研究科, 助教授 (60192473)
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| Co-Investigator(Kenkyū-buntansha) |
YAMANAKA Shoji Hiroshima Univ., Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (90081314)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2004: ¥3,100,000 (Direct Cost: ¥3,100,000)
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| Keywords | High pressure synthesis / Borides / Kondo semiconductor / Cage structure |
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| Research Abstract |
The purpose of this research is synthesis of materials that cannot be synthesized up to now under ambient pressure by the technique of a high-pressure synthesis (highest pressure= 10GPa, maximum temperature=1800℃) among rare earth borides of RB_6 and RB_<12> (R=La〜Yb). Many interesting behaviors such as valence fluctuation, Kondo effect, Kondo semiconductor, multipole ordering and new magnetic ordering will be expected to be found from the measurements of magnetism, transport, thermal properties, and the electronic structure by the optical spectroscopy.
Research representative's Iga introduced a desk-top type high-pressure synthetic equipment under the condition of the maximum temperature 1800℃ and highest pressure 4GPa. Iga tried to do a high-pressure synthesis of GdB_<12>. The optimum condition for high pressure synthesis is not yet established. Otherwise, this equipment is useful for synthesis of clathrate and skutterdite compounds.
Iga and the research collaborator Prof.Yamanaka tried to do a high pressure synthesis of GdB_<12> by using a Cubic-ambil equipment under the condition of about one hour at 1600℃ at pressure of 5GPa. X-ray analysis clarified that two phases of GdB_6 and GdB_<12> were formed in the ratio of 1:1. Furthermore we tried to do higher pressure synthesis at 10GPa and 1500℃ at last year. Octahedral ambil was included in Cubic-ambil in order to obtain the single phase of GdB_<12>. This method was developed by Prof.Yamanaka. At present the better condition is continuously searched.
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