Study on the Development of High Efficient Materials for Generation of Very Low Temperatures

产生极低温度的高效材料的开发研究

• 批准号: 05555178
• 负责人: FUKAMICHI Kazuaki
• 金额: $ 9.47万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05555178/
• 关键词: Magnetic moment; Low-temperature specific heat; Magnetic entropy; Heat capacity; Amorphous alloys; Rare earth compound; Quasicrystal; 蓄冷材; フォノン; 磁気変態; ヘビーフェルミオン; アモルファス; デバイ温度; 磁気比熱; 希土類元素; 耐候性

In the field of cryogenics, cold media such as helium and technics of generation for low temperatures are important. For gas refrigeration, high efficient reservoirs are necessary to generate very low temperatures. The reservoir receives the heat carried out by the Carnot cycle.Pb has conventionally used as a reservoir. In this case, it is impossible to generate low temperatures below 10 K.This prevents using widely helium. In the present study, the development of the high efficient reservoir has been carried out in order to overcome the berrier mentioned above.Until last year, various compounds and alloys with a heat capacity as large as possible have been investigated. It has become clear by low-temperature specific heat measurements that rare earth compound HoPb_2 with a large magnetic moment has a large heat capacity, compared with that of Er-Ni compounds which have high potentials for applications. However, this compound is not so good as the reservoir because of the ready oxidation at atmosphere. The low temperature specific heat measurements for amorphous alloys with a large random magnetic anisotropy and quasicrystals containing rare earth element have been carried out. However, the heat capacity for these materials is not so large to use the reservoir.From these results, it is concluded that the improvement of the atmospheric resistance of HoPb_2 is necessary for application.

在低温培养基领域，氦气和低温的发电技术很重要。对于气体制冷，需要高效的水库来产生非常低的温度。储层接收Carnot Cycle.PB所进行的热量。PB通常用作储层。在这种情况下，不可能产生低于10 k的低温。这可以防止使用广泛的氦气。在本研究中，为了克服上面提到的贝里尔（Berrier）而进行了高效储层的开发。直到去年，已经研究了尽可能大的热容量的各种化合物和合金。通过低温特异性热测量值，与具有较高应用的ER-NI化合物相比，具有较大的磁力容量的稀土化合物Hopb_2具有很大的热量。但是，由于大气中的现成氧化，这种化合物不如储层。已经进行了具有较大的随机磁各向异性和含有稀土元件的准磁性的无定形合金的低温特异性热量测量值。但是，这些材料的热容量使用储层并不是那么大。从这些结果，可以得出的结论是，在应用中需要改善Hopb_2的大气阻力。

项目成果

Y. Hattori: "Spin-glass-like Behaviour and Low-temperature Specific Heat of Amorphous Er_xNi_<100-x> Random Magnetic Anisotropy System" J. Phys. Condens. Matter. 7. 4193-4205 (1995)

Y. Hattori：“非晶 Er_xNi_<100-x> 随机磁各向异性系统的类旋转玻璃行为和低温比热”J. Phys。

K.Fukamichi et al: "Spin-glass-like Behavior, Random Magnetic Anisotropy and Low-temperature Specific Heat of Amorphous Er-Cu, Er-Ni and Gd-Al Alloys" Sci. Rep. RITU. A42. 65-84 (1996)

K.Fukamichi 等人：“非晶 Er-Cu、Er-Ni 和 Gd-Al 合金的类旋转玻璃行为、随机磁各向异性和低温比热” Sci。

Y. Hattori: "Spin-glass-like Behaviour and Low-temperature Specific Heat of Amprphous Er_XNi_<100-X> Random Magnetic Anisotropy System" J. Phys. Condens. Matter. 7. 4193-4205 (1995)

Y. Hattori：“双相 Er_XNi_<100-X> 随机磁各向异性系统的类旋转玻璃行为和低温比热”J. Phys。

Y. Hattori: "Electronic Specific Heat Coefficient and Magnetic Entropy of Icosahedral Mg-RE-Zn (RE=Gd, Tb and Y) Quasicrystals" J. Phys. Condens. Matter. 7. 4183-4191 (1995)

Y. Hattori：“二十面体 Mg-RE-Zn（RE=Gd、Tb 和 Y）准晶体的电子比热系数和磁熵”J. Phys。

Y.Hattori et al: "Spin-glass-like Behavior and Low-temperature Specific Heat of Amorphous Er_XNi_<100-X> Random Magnetic Anisotropy System" J.Phys. Condens. Matter. 7. 4193-4205 (1995)

Y.Hattori 等人：“非晶 Er_XNi_<100-X> 随机磁各向异性系统的类旋转玻璃行为和低温比热”J.Phys。