| Project/Area Number |
09650712
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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 |
Physical properties of metals
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| Research Institution | Tohoku University |
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Principal Investigator |
YOSHIDA Hajime Tohoku Univ., Institute for Materials Research, Researcher, 金属材料研究所, 助手 (90005950)
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| Co-Investigator(Kenkyū-buntansha) |
ABE Shunya Tohoku Univ., Institute for Materials Research, Researcher, 金属材料研究所, 助手 (00005901)
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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 |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1998: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1997: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | 3d transition metals / magnetic moment / chemical pressure / clamp-type high pressure vessel / Ti alloys / spin flop depending on temperature / ac susceptibility / MnBi / マンガン金属間化合物 / クランプ式加圧装置 / 高圧力 / 磁気秩序 / マイクロ・ボンベ |
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| Research Abstract |
The appearance of the magnetic moment in the 3d transition alloys and compounds is closely related to the distance between the magnetic atoms. Not only the direct compression but also the substitution of ions with different ionic radius can change the distance effectively. This chemical pressure is useful to produce the negative pressure for which it is hard to be realized by the physical compression means. The magnetic properties of Gd_<1-x>Y_xCo_2 in Laves phase have been investigated by examining the chemical pressure and direct compression effect. In the present studies, we notice a clamp-type microbomb as a high pressure apparatus and searched the good nonmagnetic materials for yielding the high pressure more than 1.5 GPa. The titanium alloys (Ti-6Al-4V) which have been applied to jet engines and rockets is lighter (density = 4 g/cc) and is stable at low temperatures, and its magnetic properties show a Pauli paramagnetism. The magnetic susceptibility at 4.2 K is 2.56x10^<-6> emu/g and the value of the magnetization at 10 kOe for the used high pressure vessel (-50 cc) is 5 emu/g. The mechanical features of the test pieces show higher properties than Be-Cu alloys. Pressure in the high pressure vessel below room temperature has been calibrated by measuring the resistivity of Manganin. The pressure effect of the critical temperature on spin-flop depending on the temperature was measured with ac susceptibility as its application. When Mn magnetic moments are along c-axis in the NiAs-type crystal structure, the volume of the sample becomes larger comparing with when magnetic ones are in c-plane and the value of the moment also becomes large.
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