New magnetic material R3T system with extremely large heat capacities used as heat regenerators

M. Sahashi, Y. Tokai, T. Kuriyama, H. Nakagome, R. Li, M. Ogawa, T. Hashimoto

Research output: Chapter in Book/Report/Conference proceedingChapter

36 Citations (Scopus)

Abstract

We developed a new magnetic material R3T system, where R is a rare earth metal and T a transition metal, used as a regenerator matrix in a conventional two-stage Gifford-McMahon (GM) type cryocooler. These compounds, especially Er3Ni (Erbium 3 Nickel), possess extremely large heat capacities between 4 K and room temperature because of their low Debye temperatures, about 150 K, and broadened large peaks in specific heat due to complicated ferromagnetic or antiferromagnetic spin configurations near each transition temperature, for instance 7 K for Er3Ni. The specific heat of lead (Pb) used as a conventional regenerator matrix is too small to make it possible to produce refrigeration effectively in the temperature range between 4 and 15 K, because in most non-magnetic substance, such as lead, only the lattice vibrations and the conduction electrons make a contribution to the specific heat. In this paper, we present the thermal properties, especially specific heats, for the rare earth-3d transition metal (R-T) intermetallics rich in rare earth metal and the method of fabricating spherical particles for the newly developed regenerator matrix, which is useful for a conventional two-stage GM refrigerator.

Original languageEnglish
Title of host publicationAdvances in Cryogenic Engineering
PublisherPubl by Plenum Publ Corp
Pages1175-1182
Number of pages8
Volume35
Editionpt B
ISBN (Print)0306435977
Publication statusPublished - 1990 Dec 1
EventProceedings of the 1989 Cryogenic Engineering Conference. Part 2 (of 2) - Los Angeles, CA, USA
Duration: 1989 Jul 241989 Jul 28

Other

OtherProceedings of the 1989 Cryogenic Engineering Conference. Part 2 (of 2)
CityLos Angeles, CA, USA
Period89/7/2489/7/28

ASJC Scopus subject areas

  • Engineering(all)

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