| Project/Area Number |
09640413
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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 | Muroran Institute of Technology |
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Principal Investigator |
MURAYAMA Shigeyuki Faculty of Engineering, Professor, 工学部, 教授 (10157802)
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| Co-Investigator(Kenkyū-buntansha) |
SEKINE Chihiro Faculty of Engineering, Assistant, 工学部, 助手 (60261385)
TAKANO Hideaki Faculty of Engineering, Associate Professor, 工学部, 助教授 (70154804)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | heavy-fermion system / antiferromagnetism / spin density wave / Fermi-surface nesting / Fermi liquid / gap / non-Fermi liquid / SDW |
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| Research Abstract |
Recent neuron diffraction experiment has shown that a system Ce(Ru_<1-x>Rh_2)Si_2, where Rh is substituted into the Ru site of paramagnetic heavy-fermion compound CeRu_2Si_2 with a large magnetic anisotropy along the c-axis, has an antiferromagnetic ordering for 0.05*x*0.3 with an incommensurate sinusoidal structure (the wave number and moment are along the c-axis).
Thus, in the first step of this research project we measured the resistivity, specific heat and susceptibility of the present system. The results suggest that the Fermi-surface nesting occurs along the c-axis direction in the heavy quasi-particle band at the Neel temperature with Partial gap opening of the Fermi surface. Therefore, we conclude that the antiferromagnetism is due to the spin density wave (SDW) transition following the Fermi-surface nesting. We also measured the resistivity, specific heat and susceptibility of the present system in magnetic fields. The results suggest' that the gap collapse and the Fermi surface of the heavy fermion completely recovers into a paramagnetic Fermi liquid state.
In the next step we measured the resistivity and susceptibility for .x=0.03, which is in the lower critical concentration region between the SDW and paramagnetic phases, . and for x=0.35, 0.375 and 0.40, which is in the higher critical concentration region. For x=0.03 Fermi-liquid like temperature dependence has been measured the susceptibility is temperature independent and the resistivity cc T^2 in the low temperature. On the other hand, for x = 0.35, 0.375 and 0.40 non-Fermi-liquid like temperature dependence has been observed : the susceptibility * -ROO<T> and the resistivity * T.Therefore, it is suggested that a non-Fermi-liquid phase exists in the higher critical Rh-concentration region of x *0.35 of this system.
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