铁磁/反铁磁/铁磁三层膜系统中反铁磁自旋结构及其交换各向异性

研究铁磁/反铁磁/铁磁三层膜中界面存在二次以及双二次交换耦合下反铁磁磁矩转动及其交换各向异性.结果表明,其反铁磁膜中的磁矩转动存在可逆"恢复行为"、不可逆"连续倒转行为"以及不可逆"中断倒转行为"三种情形,三种情形的出现强烈地依赖于两界面处的线性耦合和双二次耦合.钉扎界面的交换耦合与旋转界面的交换耦合相互竞争,当钉扎界面耦合占主导时,反铁磁磁矩发生可逆"恢复行为",系统出现交换偏置.在旋转界面耦合占主导情形下,其线性耦合与双二次耦合也相互竞争,分别导致反铁磁磁矩发生不可逆"连续倒转行为"和不可逆"中断倒转行为",系统都不出现交换偏置,但矫顽场都得以增强.相关结论为实验上观测的磁滞能耗以及界面垂直耦合提供了可能的解释.

Antiferromagnetic Magnetization and Exchange Anisotropy in Ferromagnetic/Antiferromagnetic/Ferromagnetic Trilayers

Phases of antiferromagnetic magnetization and exchange bias and coercivity in ferromagnetic/antiferromagnetic/ferromagnetic(FM/AF/FM)trilayers with interface quadratic and biquadratic exchange coupling are studied comprehensively.Three possible cases are found,namely reversible recovering case,irreversible continuously-reversing case and irreversible discontinuouslyreversing case.Realization of the cases strongly depends on pinned-M_(FM) interface quadratic exchange coupling J_1,free-M_(FM) interface quadratic exchange coupling J_2 and biquadratic coupling J'_2.In the reversible recovering,the exchange coupling results in an exchange bias,and there is no exchange bias in other cases.It provides possible explanation for both hysteresis energy loss and perpendicular coupling at the interface.