外应力场下铁磁/反铁磁双层膜系统中的交换偏置

采用自由能极小的方法研究了铁磁/反铁磁双层膜系统在外应力场下的交换各向异性.本模型中铁磁层具有单轴磁晶各向异性和立方磁晶各向异性，而反铁磁层仅具有单轴磁晶各向异性，但其厚度趋于半无穷.理论上解析地给出了系统的等效交换偏置和钉扎角(它显示了反铁磁层对铁磁层磁化的钉扎作用)与外应力场之间的关系.数值计算表明：系统的等效交换偏置与外磁场的方向有关，而与其大小无关；然而外应力场的大小和方向均对系统的等效交换偏置有影响，其根源在于外应力场的大小和方向都影响着钉扎角.关键词：铁磁/反铁磁双层膜交换偏置钉扎角应力场

The exchange bias in ferromagnetic/antiferro-magnetic bilayers under the stress field

Using a method in which the free energy is minimized, the exchange bias for ferromagnetic(FM)/antiferromagnetic(AFM) bilayers under the stress field is studied. The thin FM film is considered as a single crystal with cubic and uniaxial magnetocrystalline anisotropies, while the AFM film has only uniaxial magnetocrystalline anisotropy. In the semi-infinite approximation for the AFM layer, the analytical expressions have been derived for effective exchange bias and pinning angle. Numerical calculations show that the effective exchange bias depends on the angle of applied magnetic field, but not on its magnitude. However, the effective exchange bias depends not only on the angle of the stress field but also on its magnitude. The reason is that both the magnitude and angle of the stress field affect the pinning angle.