| Project/Area Number |
15540345
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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 |
SERA Masafumi Hiroshima University, Graduate School of Advanced Sciences of Matter, Professor, 大学院・先端物質科学研究科, 教授 (40196978)
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| Co-Investigator(Kenkyū-buntansha) |
TOU Hideki 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 (60295467)
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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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2004: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2003: ¥3,000,000 (Direct Cost: ¥3,000,000)
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| Keywords | multipolar ordering / Kondo effect / quadrupolar interaction / octupolar interaction / CeB_6 / phase IV / crystalline electric field / magnetic anisotropy / 軌道秩序 / 磁気秩序 / 多重極子秩序 / 多重極子相互作用 / f電子 / NdB_6 |
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| Research Abstract |
It is 1980 that the typical dense Kondo compound, CaB_6 is focused due to the appearance of the unusual phase transition. However, it is only recently that the quadrupolar and octupolar interactions play an essential role in its unusual low temperature phase. Recently, discovered new phase called as phase IV has attracted much attention and has been studied extensively to clarify its order parameter. The possibility of the appearance of the pure octupolar ordering has been discussed. In the present work, we have studied Ce_xR_<1-x>B_6(R=La,Pr,Nd) in detail and the followings are clarified. (1)The effect on the AF magnetic ordering by Nd doping in CeB_6 is very different from that by Pr doping. The interaction between Ce and Pr is strong but that between Ce and Nd is surprisingly week. As a result of that, the Kondo state in the AF state of Ce_xPr_<1-x>B_6, is suppressed rapidly but that of Ce_xNd_<1-x>B_6 survives even when the system sets in the AF magnetic phase. (2)In one ordered phase of Ce_<0.7>Pr_<0.3>B_6, the different ordering wave vector was found between the neutron scattering and X-ray one. The possibility of the separation between the orbital and spin was suspected in the rare-earth element in which the strong L-S coupling should be expected. (3)The R(=Pr,Nd) doping in phase IV induces the unusual new phase. (4)The thermoelectric power has been studied intensively in Ce_xR_<1-x>B_6(R=La,Pr,Nd) in both zero and finite magnetic fields. The new important information on the competition between the Kondo effect and RKKY interaction has been obtained.
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