1990 Fiscal Year Final Research Report Summary
Magnetism and Superconductivity of Uranium Compounds UM_3(M=Pd, Ir-Pt) and their Pseudo-Binary Systems
| Project/Area Number |
01460034
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性
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| Research Institution | Nagoya University |
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Principal Investigator |
KONTANI Masaki Nagoya Univ. Fac. of Science, Professor., 理学部, 助教授 (90022623)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUI Hisayuki Nagoya Univ. Fac. of Engineering, Assistant Prof., 工学部, 助手 (00023185)
NISHIOKA Takashi Nagoya Univ. Fac. of Science, Assistant Prof., 理学部, 助手 (10218117)
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| Project Period (FY) |
1989 – 1990
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| Keywords | uranium compounds / heavy fermion / antiferromagnetism / Specific heat in magnetic fields / NMR / magnetization in ultra-high fields. |
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| Research Abstract |
We have studied systematically magnetic properties of 1. binary U-M, 2. pseudobinary U-(M,M') and 3, ternary U-Cu-Al compounds and obtained the following results :
1.(1) U-Au system : It was found that this system contains UAu_3, U_<14>Au_<51> and UAu_2 and they all belong to the heavy fermion system. Their magnetic properties were also studied by specific heat in magnetic fields and magnetization in ultra-high fields.
(2) U-Ru and U-Os systems : All the compounds were found to be Pauli paramagnetic.
(3) U-Rh system : URh was found to be a weak ferromagnet of Tc=55k and all the others to be Curie Weirs paramagnets.
(4) U-Pd system : U_5Pd_6 was found to be a heavy. fermion antiferromagnet. UPd_4 and UPd_5 showed localized magnetic behavior, but depending much on heat-treatments.
2. (1) U_<14>Au_<51-x>Cu_x : T_N Shoved a marked decrease with x due to a chemical pressure effect.
(2) URh_<1-x>(Os,Ru)_x : Tc decreased with x , showing spin fluctuation effects around x_C=0.3.
3. Ternary UCu_<4+x>Al_<8-x> system : We prepared the ThMn_<12>-type samples for 0<less than or equal>X<less than or equal>2, and found that T_N decreases steeply with x (T_N=37K for x=0.25) and disappears for X*1.5. It was found that the compounds for X*1.5 reverl pronounced heavy fermion behavior. We also studied microscopic magnetic properties by ^<27>Al NMR.
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