中国物理B ›› 2004, Vol. 13 ›› Issue (7): 1129-1133.doi: 10.1088/1009-1963/13/7/029

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Magnetism and magnetoresistance of Er1-xSmxMn6Ge6(x=0.2－1.0) compounds

张立刚1, 李云宝1, 汪汝武2, 张绍英3, 沈保根3, 姚金雷4   

  1. (1)Department of Applied Physics, University of Science and Technology of Wuhan, Wuhan 430081, China; (2)Department of Applied Physics, University of Science and Technology of Wuhan, Wuhan 430081, China; State Key Laboratory of Magnetism, Institute of Physics and Centre for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; (3)State Key Laboratory of Magnetism, Institute of Physics and Centre for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; (4)State Key Laboratory of Magnetism, Institute of Physics and Centre for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China
  • 收稿日期:2003-11-13 修回日期:2003-12-12 出版日期:2004-07-05 发布日期:2005-07-05
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 50071041), and the State Key Development Programme for Basic Research of China (Grant No G1998061303).

Magnetism and magnetoresistance of Er1-xSmxMn6Ge6(x=0.2－1.0) compounds

Wang Ru-Wu (汪汝武)ab, Zhang Shao-Ying (张绍英)b, Zhang Li-Gang (张立刚)a, Yao Jin-Lei (姚金雷)bc, Li Yun-Bao (李云宝)a, Shen Bao-Gen (沈保根)b    

  1. a Department of Applied Physics, University of Science and Technology of Wuhan, Wuhan 430081, China; b State Key Laboratory of Magnetism, Institute of Physics and Centre for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; c State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China
  • Received:2003-11-13 Revised:2003-12-12 Online:2004-07-05 Published:2005-07-05
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 50071041), and the State Key Development Programme for Basic Research of China (Grant No G1998061303).

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摘要： Magnetic and transport properties of Er_{1-x}Sm_xMn_6Ge_6(x=0.2-1.0) have been investigated by x-ray diffraction (XRD) and magnetization measurement. Analysis of the XRD patterns indicates that the samples with x≤0.4 mainly consist of HfFe_6Ge_6-type phase and the samples with 0.6≤x≤1.0 mainly consist of YCo_6Ge_6-type phase (P6/mmm). The lattice constants and the unit cell volume increase with increasing Sm content. The antiferro－ferri－ferromagnetic transitions can be observed with increasing Sm content. The samples with x=0.2 and 0.4 order antiferromagnetically at 420 and 425K, respectively. The samples with x=0.6, 0.8 and 1.0 order from ferri- to ferromagnetically over the whole magnetic ordering temperature range. The corresponding Curie temperatures are 435, 441 and 446K, respectively. The magnetoresistance (MR) isotherms of the sample with x=0.8, measured at various temperatures, are analysed. The magnitude of MR is found to be positive below 55K and gradually increases to a relatively large value of about 5.02% at 5K in a field of 5T as the temperature is lowered. A possible explanation for the positive MR is given.

关键词: magnetism, positive magnetoresistance

Abstract: Magnetic and transport properties of Er$_{1-x}$Sm$_x$Mn$_6$Ge$_6$($x$=0.2-1.0) have been investigated by x-ray diffraction (XRD) and magnetization measurement. Analysis of the XRD patterns indicates that the samples with x≤0.4 mainly consist of HfFe$_6$Ge$_6$-type phase and the samples with 0.6≤x≤1.0 mainly consist of YCo$_6$Ge$_6$-type phase (P6/mmm). The lattice constants and the unit cell volume increase with increasing Sm content. The antiferro－ferri－ferromagnetic transitions can be observed with increasing Sm content. The samples with x=0.2 and 0.4 order antiferromagnetically at 420 and 425K, respectively. The samples with x=0.6, 0.8 and 1.0 order from ferri- to ferromagnetically over the whole magnetic ordering temperature range. The corresponding Curie temperatures are 435, 441 and 446K, respectively. The magnetoresistance (MR) isotherms of the sample with x=0.8, measured at various temperatures, are analysed. The magnitude of MR is found to be positive below 55K and gradually increases to a relatively large value of about 5.02% at 5K in a field of 5T as the temperature is lowered. A possible explanation for the positive MR is given.

Key words: magnetism, positive magnetoresistance

中图分类号:  (Magnetization curves, hysteresis, Barkhausen and related effects)

  • 75.60.Ej
75.47.Np (Metals and alloys) 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.)) 61.66.Dk (Alloys )