中国物理B ›› 2006, Vol. 15 ›› Issue (2): 449-453.doi: 10.1088/1009-1963/15/2/036

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Influence of magnetic field sweep rate on the hysteresis loops of Ni0.8Fe0.2/Fe0.5Mn0.5 exchange bias bilayer

何珂   

  1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
  • 收稿日期:2005-08-17 修回日期:2005-10-31 出版日期:2006-02-20 发布日期:2006-02-20

Influence of magnetic field sweep rate on the hysteresis loops of Ni0.8Fe0.2/Fe0.5Mn0.5 exchange bias bilayer

He Ke (何珂)   

  1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
  • Received:2005-08-17 Revised:2005-10-31 Online:2006-02-20 Published:2006-02-20

摘要: The influence of the magnetic field sweep rate on the hysteresis loops of exchange bias Ni$_{0.8}$Fe$_{0.2}$/Fe$_{0.5}$Mn$_{0.5}$ bilayers has been investigated with a vibrating sample magnetometer. It was found that the sweep rate of 13.6\,kA/4$\pi $ms is high enough to bring about obvious changes in the hysteresis loops of the exchange bias bilayer. High sweep rate in the magnetization reversal stage enlarges the coercivity of the sample, while high sweep rate in the saturation state reduces the coercivity. The above phenomena were attributed to magnetic viscosity in the ferromagnetic layer enhanced by the interface exchange interaction and domain magnetization reversals assisted by thermal fluctuation in the antiferromagnetic layer respectively.

关键词: exchange bias, coercivity, sweep rate, magnetic viscosity, Fulcomer--Charap model

Abstract: The influence of the magnetic field sweep rate on the hysteresis loops of exchange bias Ni$_{0.8}$Fe$_{0.2}$/Fe$_{0.5}$Mn$_{0.5}$ bilayers has been investigated with a vibrating sample magnetometer. It was found that the sweep rate of 13.6 kA/4$\pi $ms is high enough to bring about obvious changes in the hysteresis loops of the exchange bias bilayer. High sweep rate in the magnetization reversal stage enlarges the coercivity of the sample, while high sweep rate in the saturation state reduces the coercivity. The above phenomena were attributed to magnetic viscosity in the ferromagnetic layer enhanced by the interface exchange interaction and domain magnetization reversals assisted by thermal fluctuation in the antiferromagnetic layer respectively.

Key words: exchange bias, coercivity, sweep rate, magnetic viscosity, Fulcomer--Charap model

中图分类号:  (Magnetic properties of interfaces (multilayers, superlattices, heterostructures))

  • 75.70.Cn
75.50.-y (Studies of specific magnetic materials) 75.60.Ej (Magnetization curves, hysteresis, Barkhausen and related effects) 75.60.Jk (Magnetization reversal mechanisms) 75.30.Et (Exchange and superexchange interactions)