中国物理B ›› 2004, Vol. 13 ›› Issue (3): 397-400.doi: 10.1088/1009-1963/13/3/025

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Magnetic properties and magnetocaloric effects of Mn5G3-xGax

张绍英1, 沈保根1, 刘喜斌2   

  1. (1)State Key Laboratory for Magnetism, Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; (2)State Key Laboratory for Magnetism, Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; Chinese People's Armed Police Force Academy , Langfang 065000, China
  • 收稿日期:2003-06-17 修回日期:2003-07-04 出版日期:2004-03-06 发布日期:2005-07-06
  • 基金资助:
    Project supported by the State Key Project of Fundamental Research (Grant No G1998061303) and the National Natural Science Foundation of China (Grant No 10174094).

Magnetic properties and magnetocaloric effects of Mn5G3-xGax

Liu Xi-Bin (刘喜斌)ab, Zhang Shao-Ying (张绍英)a, Shen Bao-Gen (沈保根)a   

  1. a State Key Laboratory for Magnetism, Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; b Chinese People's Armed Police Force Academy , Langfang 065000, China
  • Received:2003-06-17 Revised:2003-07-04 Online:2004-03-06 Published:2005-07-06
  • Supported by:
    Project supported by the State Key Project of Fundamental Research (Grant No G1998061303) and the National Natural Science Foundation of China (Grant No 10174094).

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摘要： We report on the magnetic properties and magnetocaloric effects of Mn_5Ge_{3-x}Ga_x compounds with x=0.1, 0.2, 0.3, 0.4, 0.6 and 0.9. All samples crystallize in the hexagonal Mn_5Si_3-type structure with space group P6_3/mcm and order ferromagnetically. The Curie temperature of these compounds decreases with increasing x, from 306K (x=0.1) to 274K (x=0.9). The average Mn magnetic moments increases with increasing Ga content, reaching a maximum value at x=0.6. The magnetic entropy changes in these compounds are determined from the temperature and field dependence of the magnetization using the thermodynamic Maxwell relation. The Ga substitution has two kinds of influence on the magnetocaloric effect (MCE) of Mn_5Ge_3. One is that the magnitude of the magnetic entropy change decreases, the other is that the MCE peak becomes broadened.

关键词: magnetic properties, magnetic entropy change

Abstract: We report on the magnetic properties and magnetocaloric effects of Mn$_5$Ge$_{3-x}$Ga$_x$ compounds with $x$=0.1, 0.2, 0.3, 0.4, 0.6 and 0.9. All samples crystallize in the hexagonal Mn$_5$Si$_3$-type structure with space group P6$_3$/mcm and order ferromagnetically. The Curie temperature of these compounds decreases with increasing x, from 306K (x=0.1) to 274K (x=0.9). The average Mn magnetic moments increases with increasing Ga content, reaching a maximum value at x=0.6. The magnetic entropy changes in these compounds are determined from the temperature and field dependence of the magnetization using the thermodynamic Maxwell relation. The Ga substitution has two kinds of influence on the magnetocaloric effect (MCE) of Mn$_5$Ge$_3$. One is that the magnitude of the magnetic entropy change decreases, the other is that the MCE peak becomes broadened.

Key words: magnetic properties, magnetic entropy change

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

  • 75.30.Sg
75.30.Kz (Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)) 75.40.-s (Critical-point effects, specific heats, short-range order) 75.30.Cr (Saturation moments and magnetic susceptibilities) 75.60.Ej (Magnetization curves, hysteresis, Barkhausen and related effects)