中国物理B ›› 2007, Vol. 16 ›› Issue (7): 1817-1821.doi: 10.1088/1009-1963/16/7/001

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Magnetocaloric effect in ErCo2 compound

邹君鼎, 沈保根, 孙继荣   

  1. State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
  • 收稿日期:2007-03-02 出版日期:2007-07-20 发布日期:2007-07-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No~50571112) and the National Basic Research Program of China (Grant No~2006CB601101).

Magnetocaloric effect in ErCo2 compound

Zou Jun-Ding(邹君鼎), Shen Bao-Gen(沈保根)† , and Sun Ji-Rong(孙继荣)   

  1. State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
  • Received:2007-03-02 Online:2007-07-20 Published:2007-07-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No~50571112) and the National Basic Research Program of China (Grant No~2006CB601101).

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摘要： The ErCo 2 compound is prepared by arc-melting and its entropy changes are calculated using Maxwell relation. Its entropy change reaches 38 J/(kg $\cdot$ K) and its refrigerant capacity achieves 291 J/kg at 0--5 T. The mean field approximation is used to calculate the magnetic entropy of ErCo 2 compound. Results estimated by using the Maxwell relation deviate from mean field approximation calculations in ferrimagnetic state; however, the data obtained by the two ways are consistent in the vicinity of phase transition or at higher temperatures. This indicates that entropy changes are mainly derived from magnetic degree of freedom, and the lattice has almost no contribution to the entropy change in the vicinity of phase transition but its influence is obvious in the ferrimagnetic state below TC.

关键词: magnetocaloric effect, mean field approximation, metamagnetic transition

Abstract: The ErCo 2 compound is prepared by arc-melting and its entropy changes are calculated using Maxwell relation. Its entropy change reaches 38 J/(kg $\cdot$ K) and its refrigerant capacity achieves 291 J/kg at 0--5 T. The mean field approximation is used to calculate the magnetic entropy of ErCo 2 compound. Results estimated by using the Maxwell relation deviate from mean field approximation calculations in ferrimagnetic state; however, the data obtained by the two ways are consistent in the vicinity of phase transition or at higher temperatures. This indicates that entropy changes are mainly derived from magnetic degree of freedom, and the lattice has almost no contribution to the entropy change in the vicinity of phase transition but its influence is obvious in the ferrimagnetic state below TC.

Key words: magnetocaloric effect, mean field approximation, metamagnetic transition

中图分类号:  (Magnetocaloric effect, magnetic cooling)

  • 75.30.Sg
65.40.G- (Other thermodynamical quantities) 75.30.Kz (Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)) 75.40.Cx (Static properties (order parameter, static susceptibility, heat capacities, critical exponents, etc.)) 75.50.Gg (Ferrimagnetics)