| Project/Area Number |
09640428
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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 |
固体物性Ⅱ(磁性・金属・低温)
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| Research Institution | Shinshu University |
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Principal Investigator |
YAMADA Hideji Faculty of Science, Shinshu University, Professor, 理学部, 教授 (00023151)
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| Co-Investigator(Kenkyū-buntansha) |
TERAO Kiyosi Faculty of Science, Shinshu University, Associate Professor, 理学部, 助教授 (40020664)
NAGAI Hiroyuki Faculty of Science, Shinshu University, Professor, 理学部, 教授 (60020674)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1997: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Itinerant-electrons / Metamagnetism / Electronic structure / Intermetallic compounds / 遍歴電子模型 |
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| Research Abstract |
(1) B20-type compounds MnSi and FeSi
Electronic structures of MnSi and FeSi with the B20-type crystal structure have been calculated by the self-consistent LMTO method. It has been shown, by the numerical calcu-lations in the fixed-spin-moment procedure, that MnSi shows a first-order transition from the magnetic to non-magnetic state and then the metamagnetic transition takes place with decreasing lattice constant. This result is consistent with recent results observed under high pressures. Similar calculations have also carried out for semi conducting compound FeSi and the critical field of the metamagnetic transition was estimated. Our calculated value of the critical field is in good agreement with the value observed very recently by Russian group.
(2) NMR measurements for CeCoィイD24ィエD2B and RィイD22ィエD2CoィイD27ィエD2BィイD23ィエD2
NMR measurements of CeCoィイD24ィエD2B and RィイD22ィエD2CoィイD27ィエD2BィイD23ィエD2 (R=Y, Ce, Nd, Sm, Gd) have been carried out and magnetic moments of Co in these compounds have
… More
been estimated. It has been found that the orbital moment of Co at 2c site is relatively large in CeCoィイD24ィエD2B. For CeィイD22ィエD2CoィイD27ィエD2BィイD23ィエD2 the metamagnetic transition was observed at 70 kOe.
(3) Metamagnetic transition and susceptibility maximum in UCoAl
Metamagnetic transition and susceptibility maximum have been observed in 5f-electron system UCoAl. The observed results were analysed on the model of spin-fluctuations in the itinerant-electron system. The temperature dependence of the critical field, estimated with the susceptibility maximum temperature, was found to be in excellent agreement with the observed result. It was shown that the theoretical model for the itinerant-electron meta- magnetism could be applicable even to such a 5f-electron system.
(4) (Sc,Ti)FeィイD22ィエD2 with C14-type Laves phase compound
Electronic structures of ScFeィイD22ィエD2, TiFeィイD22ィエD2 and their alloys have been calculated by the self- consistent LMTO method. It has been found by numerical calculations that three magnetic states with large-moment, small-moment and antiferromagnetic states are stable in these compounds. The volume dependence of these magnetic states was also discussed. A good agreement between the calculated and observed results has been obtained. Less
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