1992 Fiscal Year Final Research Report Summary
The magnetic interactions between rare-earth and transition elements in the intermetallic compound
| Project/Area Number |
03452035
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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 | Shinshu University |
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Principal Investigator |
NAGAI Hiroyuki Shinshu University, Department of Physics., Professor., 理学部, 教授 (60020674)
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| Co-Investigator(Kenkyū-buntansha) |
AMAKO Yasushi Shinshu University, Department of Physics, Assistant, 理学部, 助手 (90222679)
TERAO Kiyoshi Shinshu University, Department of Physics, Assistant, 理学部, 助手 (40020664)
YOSHIE Hiroshi Shinshu University, Department of Physics, Assistant Professor., 理学部, 助教授 (10020661)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Intermetallic compound / Coexistence of magnetic interactions / Permanent magnet / Magnetic anisotropy |
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| Research Abstract |
In the final year, the remain measurements were carried out. According to the electronic resistances of R(Fe,Mn)_<12> where R is the rare earth element, the rapid increase due to the transition to the antiferromagnetic state was observed and explained by the similar method for CrMn alloy. The saturation magnetizations of RMn_<12> are smaller than the expected values for R^<3+> by assuming the antiferromagnetic coupling of Mn atoms. This fact suggests the existence of the strong interaction between R and Mn atoms. The R-Mn interaction was observed by ^<55>Mn NMR in the temperature range between T_C and T_N where T_C (<10K) is the magnetic ordering point of R atoms and T_N ( 100K) is that of Mn atoms. From the Mossbauer effect of ^<57>Fe in R(Fe,Mn)_<12>, The site preference of Fe atom was quantatively obtained. 8f-site is most preferential and 8i-site is hard. In the lower density of Fe , the population rate of Fe (8j/8f) is estimated to be about 30%.
The another object of study is to develop strong ferromagnetic substances. In order to study the basic properties of permanent magnets, the ferromagnetic compound Gd_5Si_4 was selected as a start substance and substituted to increase the magnetic anisotropy. The contribution of R atom to the magnetic anisotropy was also investigated. As a result, the substance with higher Curie temperature was not found. While the magnetic moment per atom was larger than others. The strong permanent magnet is possible at low temperature. The NMR study of R_2Co_<14>B indicates the contribution to the magnetic anisotropy of Co sites. From these results the conditions of the possibility of the strong permanent magnet are pointed out.
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