铁磁/反铁磁双层膜系统中的磁畴动力学行为

Dynamic behaviors of domain wall in FM/AFM bilayers

比较了铁磁单层膜与铁磁/反铁磁双层膜结构中的磁畴演化行为,发现由于反铁磁层膜对铁磁层膜的耦合作用使得系统的磁畴壁厚度、磁畴壁等效质量、磁畴壁移动速度等发生了改变,系统的矫顽场增强,并出现了交换偏置场.文章具体研究了反铁磁层耦合作用下其磁畴壁厚度、等效质量以及磁畴壁移动速度等与反铁磁层的净磁化、磁各向异性、界面耦合强度以及温度等的关系;并研究了其对铁磁/反铁磁双层膜中的交换偏置场、矫顽场的影响.进而从磁畴结构的形成及其演化上揭示了铁磁/反铁磁双层膜中出现交换偏置以及矫顽场增加的物理机制.

The magnetic domain evolution behaviors of ferromagnetic （FM） monolayer and ferromagnetic （FM）/antiferromagnetic （AFM） bilayer are compared and analyzed. The results indicate that the equivalent width, mass and velocity of magnetic domain wall are changed, then the coercivity is enhanced and the exchange bias is present due to the exchange coupling between anti- ferromagnetic and ferromagnetic layer. The results also show that the equivalent width, mass and velocity of magnetic domain wall for FM/AFM bilayers system could be varied with the change of the net magnetization of antiferromagnetic layer, the magnetic anisotropy constants of FM and AFM layer, the exchange coupling constant of antiferromagnetic layer, interface exchange coupling constant and the temperature, and the relevant influences on the coercivity and exchange bias are discussed. So, the physical mechanisms of the emergence of exchange bias and enhancement of coercivity are discovered by the formation and evolution of the domain wall.