Training effect in ferro (F)/antiferromagnetic (AF) exchange coupled systems: Dependence on AF thickness
Training effect in ferro (F)/antiferromagnetic (AF) exchange coupled systems: Dependence on AF thickness
复制标题
DOI：
10.1063/1.1447869
复制
发表时间：
2002-05
影响因子：
3.2
通讯作者：
K. Zhang;T. Zhao;H. Fujiwara
中科院分区：
文献类型：
--
作者：
K. Zhang;T. Zhao;H. Fujiwara
使用溅射 NiFe/IrMn 双层对多晶铁 (F)/反铁磁 (AF) 交换耦合系统中的训练效应进行的系统研究表明，随着 AF 层厚度的增加，训练效应的类型从一种类型 (I 型) 变为另一种类型 (II 型)。在类型 I 中，固定方向上的磁滞回线随着外加磁场的周期从两侧收缩，而在类型 II 中，磁滞回线随着回线收缩而向正固定方向移动。这种现象可以理解为 AF 晶粒的稳定有助于增强矫顽力和与施加场循环的交换偏置。这一结论基于我们最近提出的扩展 Fulcomer 和 Charap 模型，其中纳入了 AF 颗粒之间的直接正负交换耦合。
Systematic investigation on the training effect in polycrystalline ferro (F)/antiferromagnetic (AF) exchange coupled systems using sputtered NiFe/IrMn bilayers has revealed that the type of the training effect changes from one type (Type I) to another (Type II) with increasing the AF layer thickness. In Type I the hysteresis loop in the pinned direction shrinks from both sides with the cycle of the applied field, while in Type II it shifts toward the positive pinned direction accompanied by loop shrinkage. This phenomenon can be understood as the stabilization of both AF grains contributing to the enhancement of coercivity and to the exchange biasing with cycles of applied field. This conclusion is based on our recently proposed extended Fulcomer and Charap’s model in which direct positive and negative exchange coupling between the AF grains is incorporated.