中国物理B ›› 2007, Vol. 16 ›› Issue (12): 3848-3852.doi: 10.1088/1009-1963/16/12/049

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Magnetic properties and magnetic entropy changes of La1-xPrxFe11.5Si1.5 compounds with 0≤x≤ 0.5

李养贤1, 沈 俊2, 高 博3, 闫丽琴3, 张宏伟3, 胡凤霞3, 孙继荣3   

  1. (1)School of Material Science and Engineering, Hebei University of Technology, Tianjin 300130, China; (2)School of Material Science and Engineering, Hebei University of Technology, Tianjin 300130, China;State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China; (3)State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
  • 出版日期:2007-12-20 发布日期:2007-12-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 50571112), the National Basic Research Program of China (Grant No 2006CB601101) and the Program of Chinese Academy of Sciences (Grant No KJCX2-YW-W02).

Magnetic properties and magnetic entropy changes of La1-xPrxFe11.5Si1.5 compounds with 0≤x≤ 0.5

Shen Jun (沈俊)a)b), Gao Bo (高博)b), Yan Li-Qin (闫丽琴)b), Li Yang-Xian (李养贤)a), Zhang Hong-Wei (张宏伟)b), Hu Feng-Xia (胡凤霞)b), and Sun Ji-Rong (孙继荣)b)   

  1. a School of Material Science and Engineering, Hebei University of Technology, Tianjin 300130, China; b State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
  • Online:2007-12-20 Published:2007-12-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 50571112), the National Basic Research Program of China (Grant No 2006CB601101) and the Program of Chinese Academy of Sciences (Grant No KJCX2-YW-W02).

摘要: Magnetic properties and magnetic entropy changes in LaFe$_{11.5}$Si$_{1.5}$ have been investigated by partially substituting Pr by La. It is found that La$_{1 - x}$Pr$_{x}$Fe$_{11.5}$Si$_{1.5}$ compounds remain cubic NaZn$_{13}$-type structures even when the Pr content is increased to 0.5, i.e. $x = 0.5$. Substitution of Pr for La leads to a reduction in both the crystal constant and the Curie temperature. A stepwise magnetic behaviour in the isothermal magnetization curves is observed, indicating that the characteristic of the itinerant electron metamagnetic (IEM) transition above TC becomes more prominent with the Pr content increasing. As a result, the magnetic entropy change is remarkably enhanced from 23.0 to 29.4\,J/kg$\cdot$K as the field changes from 0 to 5\,T, with the value of $x$ increasing from 0 to 0.5. It is more attractive that the magnetic entropy changes for all samples are shaped into high plateaus in a wide range of temperature, which is highly favourable for Ericsson-type magnetic refrigeration.

关键词: La_{1 - x}Pr_{x}Fe_{11.5}Si_{1.5} compounds, magnetic entropy change, magnetic property, itinerant electron metamagnetic transition

Abstract: Magnetic properties and magnetic entropy changes in LaFe$_{11.5}$Si$_{1.5}$ have been investigated by partially substituting Pr by La. It is found that La$_{1 - x}$Pr$_{x}$Fe$_{11.5}$Si$_{1.5}$ compounds remain cubic NaZn$_{13}$-type structures even when the Pr content is increased to 0.5, i.e. $x = 0.5$. Substitution of Pr for La leads to a reduction in both the crystal constant and the Curie temperature. A stepwise magnetic behaviour in the isothermal magnetization curves is observed, indicating that the characteristic of the itinerant electron metamagnetic (IEM) transition above TC becomes more prominent with the Pr content increasing. As a result, the magnetic entropy change is remarkably enhanced from 23.0 to 29.4 J/kg$\cdot$K as the field changes from 0 to 5 T, with the value of $x$ increasing from 0 to 0.5. It is more attractive that the magnetic entropy changes for all samples are shaped into high plateaus in a wide range of temperature, which is highly favourable for Ericsson-type magnetic refrigeration.

Key words: La1-xPrxFe11.5Si1.5 compounds, magnetic entropy change, magnetic property, itinerant electron metamagnetic transition

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

  • 75.30.Sg
61.66.Fn (Inorganic compounds) 65.40.G- (Other thermodynamical quantities) 75.30.Kz (Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)) 75.60.Ej (Magnetization curves, hysteresis, Barkhausen and related effects)