坡莫合金纳米盘中交换偏置的涡旋动力学行为

提出铁磁反铁磁界面交换作用模型,并采用数值计算方法对在交换偏置场作用下坡莫合金纳米盘中涡旋的动力学行为进行研究.计算表明,在这种涡旋形钉扎场的作用下,涡旋核的螺旋运动频率会增大,而且随着铁磁/反铁磁之间界面交换作用的增加而线性增加;同时涡旋核向平衡位置的弛豫时间缩短,交换偏置作用起到了阻尼的效果.当有外磁场作用时,交换偏置使得铁磁层涡旋核运动轨迹不再是简单的螺旋曲线,核到盘中心的距离振荡增加直到达到一个稳定值.

Dynamic Behavior of Exchange-Biased Vortex in Permalloy Nanodisk

The dynamic behavior of the exchanged-biased vortex in permalloy nanodisk was studied by numerical calculations based on the interfacial exchange model we developed.It was found that the frequency of the gyrotropic motion of the vortex core increases linearly with the increasing interfacial exchange constant between ferromagnetic and antiferromagnetic layers under the action of the vortex-shaped pinning field.Meanwhile,the relaxation time required from the vortex core to equilibrium position shortens,thus p...