Study of Itinerant Electron Magnetism on Amorphous (Hf, Ta)Fe_2 Alloys
| Project/Area Number |
04640319
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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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 | Muroran Institute of Technology |
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Principal Investigator |
MURAYAMA Shigeyuki Muroran Institute of Technology, Faculty of Engineering, Associate Professor, 工学部, 助教授 (10157802)
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| Co-Investigator(Kenkyū-buntansha) |
TAKANO Hideaki Muroran Institute of Technology, Faculty of Engineering, Associate Professor, 工学部, 助教授 (70154804)
HOSHI Kensuke Muroran Institute of Technology, Faculty of Engineering, Professor, 工学部, 教授 (00002866)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1993: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1992: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Amorphous alloys / Itinerant electron magnetism / Mossbauer effect / Thermal expansion / Magnetovolume effect / Coefficient of the electron specific heat / Resistivity / Magnetoresistivity / 遍歴電子型磁性 / 比熱 / 遍歴型電子磁性 / メスバウア効果 / スパッタリング |
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| Research Abstract |
Hexagonal Laves-phase pseudo-binary intermetallic (Hf, Ta)Fe_2 alloys show two-stage magnetic transition : para- antiferro- ferro-magnetism with decreasing temperature. We have made a detailed study of the magnetism on amorphous (Hf, Ta)Fe_2 alloys obtained from high-rate dc sputtering technique.
1. The magnetization and Mossbauer effect have been measured. The ferromagnetic moment and Curie temperature of the amorphous alloys continuously decrease with increasing Ta concentration x and well follow the Rhodes-Wohlfarth curve. This is a typical character of the itinerant electron ferromagnetism. The local Fe moment is found to be inhomogeneously distributed depending on the local environment effects.
2. The thermal expansion has been measured by using gauge method. A positive magnetovolume effect has been observed near and below the Curie temperature. This magnitude decreases with increasing x and almost disappears for x >= 0.7.
3. The specific heat has been measured by using light-chopped ac method. A small peak in the specific heat has been measured at about the Curie temperature for x =< 0.3. Below 10 K the temperature dependence of the specific heat follows gammaT + betaT^3. The coefficient of the electronic specific heat gamma is much larger compared for the common metal and even larger than the crystalline phase with the same chemical composition.
4. The resistivity and magnetoresistivity have been measured. The amount increased below the Curie temperature in the resistivity agrees with the universal function of the ferromagnetic moment with the Ta concentration and external field with implicit parameters. These facts suggest that the variation of the resistivity is mainly due to the magnetic scattering of the conduction electron at the local Fe site. Below 10 K it follows T^<1/2> law and is almost independent of x. This seems to be due the contribution from the fundamental amorphous structure and will be a next interesting subject.
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Report
(3 results)
Research Products
(12 results)
