| Project/Area Number |
01540259
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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 | Kanazawa University (1990)
Tohoku University (1989) |
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Principal Investigator |
SUZUKI Haruhiko Kanazawa Univ. Faculty of Science : Asociate Professor, 理学部, 助教授 (50004370)
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| Co-Investigator(Kenkyū-buntansha) |
SAKATSUME Shin'ichi Tohoku Univ. Cryogenic Senter : Research Asociate, 助手 (20005896)
後藤 輝孝 東北大学, 科学計測研究所, 助教授 (60134053)
酒井 治 東北大学, 理学部, 助教授 (60005957)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1990: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1989: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Nuclear Magnetism / Nuclear Cooling / Adiabatic Demagneti Zed Cooling / Ultra Low Temperature / Spin Glass / スピン・グラス / 核スピン・オ-ダ- / 核断熱消磁冷却 / スピン・ガラス / SQUZD |
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| Research Abstract |
Among a large number of pure metals, only in Cu the nuclear spins have been cooled down below their spontaneous ordering temperature. Though great efforts have been devoted to achieve the nuclear spin order, the clear evidence of oraering has not yet been observed in other metals so far. We are interested in the nuclear spin ordering in Sc metal which is known as the highly exchange enhanced Pauli paramagnetic metals. In order to achieve the nuclear spin ordering in Sc metal, we constructed two stage demagnetiziaton cryostat. Before doing the two stage demagnetized cooling experiment, we measured a temperature dependance of the magnetic susceptibility of Sc metal above 0.25 mk by the one stage demagnetized cooling. Result can be understood by the spin glass phenomenon of iron impurity in Sc metal. Then we performed the two stage semagnetized experiment. By a first stage demagntization cooling, we cooled down the Sc metal to 0.25 mk. From this temperature and 7 T initial magnetic field, nuclear spins in Sc metal was cooled down below 50 nk by the demagnetization. The warming up behaviour of the ac magnetic susceptibility has been measured following demagnetization cooling of Sc specimen itself. Amtiferromagnetic-like maximum of the magnetic susceptibility was observed. Nuclear spins stayed in the ordered state about 45 minutes. This is the second observation of the nuclear spin ordering in metal elements. But we have not yet deter mined the ordering temperature T_N. We are going to make further experiment to clear the properties of the nuclear magnetism of Sc metal.
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