| Project/Area Number |
10440096
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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 |
固体物性Ⅱ(磁性・金属・低温)
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
AMITSUKA Hiroshi Hokkaido University, Graduate School of Science, Lecturer, 大学院・理学研究科, 講師 (40212576)
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| Co-Investigator(Kenkyū-buntansha) |
TENYA Kenichi Hokkaido University, Graduate School of Science, Instructor, 大学院・理学研究科, 助手 (70261279)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥5,500,000 (Direct Cost: ¥5,500,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥5,000,000 (Direct Cost: ¥5,000,000)
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| Keywords | Non Fermi Liquid / Kondo Effects / Multi-Channel Kondo Effects / Non-Kramers Configuration / Heavy Fermion / Weak Antiferromagnetism / Pressure Effects / Neutron Scattering / ウラン希薄合金 / 非クラマース電子系 / 比熱 / 電気抵抗 |
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| Research Abstract |
Single-U-ion properties of heavy-electron compound URuィイD22ィエD2SiィイD22ィエD2 have been investigated by a series of diluting experiments on RィイD21-xィエD2UィイD2xィエD2RuィイD22ィエD2SiィイD22ィエD2(R=Y, Th; x 【less than or equal】0.07). A strong uniaxial magnetic anisotropy of local 5f moments is commonly observed throughout the dilutions. From a large enhancement of Χ and C/T at T → 0, we suggest a non-Kramers, magnetic doublet ΓィイD25ィエD2 (fィイD12ィエD1) to be eminently suitable for the crystal-field lowest level, contrary to general views of low-lying singlets for the periodic system. We have further confirmed absence of the conventional Kondo effect in all these dilutions. A strong suppression of 5f moments at low temperatures accompanies a non-trivial lnT decrease in ρ and a small change in the magnetic entropy. Specific-heat measurements in magnetic fields up to 12 T have revealed no sign of the residual entropy, eliminating the simple application of the two-channel Kondo theory to the present alloys. We have also found through neutron-scattering experiments that the periodic system URuィイD22ィエD2SiィイD22ィエD2 undergoes a new phase transition under high pressure.
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