中国物理B ›› 1999, Vol. 8 ›› Issue (12): 919-926.doi: 10.1088/1004-423X/8/12/007

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CONTRIBUTION FROM MOLDCULAR FIELD TO THE TEMPERATURE DEPENDENCE OF TUNNELING MAGNETORESISTANCE

王俊忠1, 李伯藏2, 高俊山3   

  1. (1)Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; (2)Institute of Theoretical Physics, Shanxi University, Thiyuan 030006, China; (3)North China Institute of Astronautic Engineering, Langfang, 065000, China
  • 收稿日期:1999-03-17 出版日期:1999-12-15 发布日期:2005-06-29

CONTRIBUTION FROM MOLDCULAR FIELD TO THE TEMPERATURE DEPENDENCE OF TUNNELING MAGNETORESISTANCE

WANG JUN-ZHONG (王俊忠)a, LI BO-ZANG (李伯藏)ab, GAO JUN-SHAN (高俊山)c   

  1. a Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; 
    b Institute of Theoretical Physics, Shanxi University, Thiyuan 030006, China; c North China Institute of Astronautic Engineering, Langfang, 065000, China
  • Received:1999-03-17 Online:1999-12-15 Published:2005-06-29

摘要: Based on the nearly free-electron approximation, we have investigaed the temperature (T) dependence of spin-polarized tunneling in the magnetic tunnel junction with an asymmetrical barrier, with emphasis on the variation of molecular field with T in the same way as that of surface magnetization. It is found that the Slonczewski model can describe well the T depen-dence of spin-polarized tunneling, while the Julliere model only describes the T dependence of JMR qualitatively, but does accurately that of the difference of tunneling conductance between the parallel and antiparallal alignments for the magnetizations of FMs; Differing from the pre-vious finding, we find the electron spin polarization is not strictly proportional to the surface magnetization, for the former decreases with the increasing T more rapidly than the latter does.

Abstract: Based on the nearly free-electron approximation, we have investigaed the temperature (T) dependence of spin-polarized tunneling in the magnetic tunnel junction with an asymmetrical barrier, with emphasis on the variation of molecular field with T in the same way as that of surface magnetization. It is found that the Slonczewski model can describe well the T depen-dence of spin-polarized tunneling, while the Julliere model only describes the T dependence of JMR qualitatively, but does accurately that of the difference of tunneling conductance between the parallel and antiparallal alignments for the magnetizations of FMs; Differing from the pre-vious finding, we find the electron spin polarization is not strictly proportional to the surface magnetization, for the former decreases with the increasing T more rapidly than the latter does.

中图分类号:  (Magnetotransport phenomena; materials for magnetotransport)

  • 75.47.-m
75.70.Rf (Surface magnetism) 75.60.Ej (Magnetization curves, hysteresis, Barkhausen and related effects) 73.40.Gk (Tunneling)