中国物理B ›› 2007, Vol. 16 ›› Issue (7): 2123-2130.doi: 10.1088/1009-1963/16/7/055

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Theoretical investigation of exchange bias

王怀玉1, 熊知杰2, 丁泽军2   

  1. (1)Department of Physics, Tsinghua University, Beijing 100084, China ; (2)Department of Physics, University of Science and Technology of China, Hefei 230026, China
  • 收稿日期:2006-11-24 修回日期:2007-01-18 出版日期:2007-07-20 发布日期:2007-07-04
  • 基金资助:
    Project supported by the National~Natural Science Foundation of China (Grant Nos 10574121, 90406024 and 10025420), Chinese Education Ministry and Chinese Academy of Sciences.

Theoretical investigation of exchange bias

Xiong Zhi-Jie(熊知杰)a), Wang Huai-Yu(王怀玉)b), and Ding Ze-Jun(丁泽军)a)   

  1. a Department of Physics, University of Science and Technology of China, Hefei 230026, China; b Department of Physics, Tsinghua University, Beijing 100084, China
  • Received:2006-11-24 Revised:2007-01-18 Online:2007-07-20 Published:2007-07-04
  • Supported by:
    Project supported by the National~Natural Science Foundation of China (Grant Nos 10574121, 90406024 and 10025420), Chinese Education Ministry and Chinese Academy of Sciences.

摘要: The exchange bias of bilayer magnetic films consisting of ferromagnetic (FM) and antiferromagnetic (AFM) layers in an uncompensated case is studied by use of the many-body Green's function method of quantum statistical theory. The effects of the layer thickness and temperature and the interfacial coupling strength on the exchange bias HE are investigated. The dependence of the exchange bias HE on the FM layer thickness and temperature is qualitatively in agreement with experimental results. When temperature varies, both the coercivity HC and HE decrease with the temperature increasing. For each FM thickness, there exists a least AFM thickness in which the exchange bias occurs, which is called pinning thickness.

关键词: exchange bias, coercivity, uncompensated case, Heisenberg Hamiltonian

Abstract: The exchange bias of bilayer magnetic films consisting of ferromagnetic (FM) and antiferromagnetic (AFM) layers in an uncompensated case is studied by use of the many-body Green's function method of quantum statistical theory. The effects of the layer thickness and temperature and the interfacial coupling strength on the exchange bias HE are investigated. The dependence of the exchange bias HE on the FM layer thickness and temperature is qualitatively in agreement with experimental results. When temperature varies, both the coercivity HC and HE decrease with the temperature increasing. For each FM thickness, there exists a least AFM thickness in which the exchange bias occurs, which is called pinning thickness.

Key words: exchange bias, coercivity, uncompensated case, Heisenberg Hamiltonian

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

  • 75.60.Ej
75.10.-b (General theory and models of magnetic ordering) 75.50.Ee (Antiferromagnetics) 75.70.Ak (Magnetic properties of monolayers and thin films)