Temperature dependence of the exchange bias properties of ferromagnetic/antiferromagnetic polycrystalline bilayers
Temperature dependence of the exchange bias properties of ferromagnetic/antiferromagnetic polycrystalline bilayers
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DOI：
10.1016/j.jmmm.2014.07.021
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发表时间：
2014-12
影响因子：
2.7
通讯作者：
D. Ledue;A. Maître;F. Barbe;L. Lechevallier
中科院分区：
文献类型：
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作者：
D. Ledue;A. Maître;F. Barbe;L. Lechevallier
Monte Carlo模拟使用的颗粒级模型的耦合铁磁/反铁磁（F/AF）层，占fandafgrains上的热效应进行计算的交换偏置性能的温度依赖性。还研究了F晶粒间耦合和晶粒尺寸色散的影响。预测的交换偏置和矫顽场的热变化与实验定性一致。对于单分散颗粒，它表明，交换场消失的阻塞温度以下的AF颗粒，即当AF颗粒变得足够不稳定，使他们切换，但之后的AF颗粒。在相同温度下，由于与AF层的耦合，矫顽场呈现最大值。还证明，粒度分布增加了每层的稳定性，从而改善了交换偏置性能。
Monte Carlo simulations using a granular level model of coupled ferromagnetic/antiferromagnetic (F/AF) layers that accounts for thermal effects on bothFandAFgrains are performed to calculate the temperature dependence of the exchange bias properties. The influence of the coupling betweenFgrains and of the grain size dispersion is also investigated. The predicted thermal variation of the exchange bias and coercive fields are in good qualitative agreement with experiment. For monodispersive grains, it is shown that the exchange field vanishes below the blocking temperature of theAFgrains, i.e. when theAFgrains become sufficiently unstable, so that they switch but after theFgrains. At the same temperature, the coercive field exhibits a maximum due to the coupling with theAFlayer. It is also evidenced that a grain size distribution increases the stability of each layer, thus improving the exchange bias properties.