Low-frequency dynamic hysteresis in exchange-coupled Ni 81 Fe 19 / I r 22 Mn 78 bilayers
Low-frequency dynamic hysteresis in exchange-coupled Ni 81 Fe 19 / I r 22 Mn 78 bilayers
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DOI：
10.1103/physrevb.64.184416
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发表时间：
2001-10
影响因子：
3.7
通讯作者：
Haiwen Xi;R. White;S. Mao;Zheng Gao;Zhi-jian Yang;E. Murdock
中科院分区：
文献类型：
--
作者：
Haiwen Xi;R. White;S. Mao;Zheng Gao;Zhi-jian Yang;E. Murdock
The dynamics of hysteresis, including the training effect, the field sweep rate dependence, and the field strength dependence of the exchange bias and coercivity, is experimentally investigated in exchange-coupled ${\mathrm{Ni}}_{81}{\mathrm{Fe}}_{19}{/\mathrm{I}\mathrm{r}}_{22}{\mathrm{Mn}}_{78}$ bilayers in the low-frequency range. The dependence of the exchange field and the coercivity with the number of measurement cycles is well described by a power-law function in which the index varies with the ${\mathrm{Ir}}_{22}{\mathrm{Mn}}_{78}$ thickness. We have also found that the exchange bias depends upon the sweep rate according to a power law. This ``training effect'' and the dynamic response of the exchange biasing can be explained by a thermal fluctuation model in which the antiferromagnet is assumed to be composed of grains which undergo thermal fluctuations.
The dynamics of hysteresis, including the training effect, the field sweep rate dependence, and the field strength dependence of the exchange bias and coercivity, is experimentally investigated in exchange-coupled ${\mathrm{Ni}}_{81}{\mathrm{Fe}}_{19}{/\mathrm{I}\mathrm{r}}_{22}{\mathrm{Mn}}_{78}$ bilayers in the low-frequency range. The dependence of the exchange field and the coercivity with the number of measurement cycles is well described by a power-law function in which the index varies with the ${\mathrm{Ir}}_{22}{\mathrm{Mn}}_{78}$ thickness. We have also found that the exchange bias depends upon the sweep rate according to a power law. This ``training effect'' and the dynamic response of the exchange biasing can be explained by a thermal fluctuation model in which the antiferromagnet is assumed to be composed of grains which undergo thermal fluctuations.