Spin waves in ferromagnetic/antiferrmagnetic bilayers under the stress field

Abstract

Using a method of free energy minimization, the spin wave, namely the ferromagnetic resonance, of ferromagnetic (FM)/antiferromagnetic (AFM) bilayers under the stress field has been investigated. The thin FM film is taken to be a single crystal with cubic or uniaxial magnetocrystalline anisotropy, while the thickness of AFM layer is semi-infinite and has single uniaxial magnetocrystalline anisotropy. Numerical calculation shows that stress field and the interface coupling strength will affect the behavior of FM resonance only under low magnetic field, and there are two branches of FMR modes at the critical field, which distinguishes between the weak and strong external field. The critical field depends on the direction of stress field. On the other hand, the change of the direction of the stress field can weakly affect magnetocrystalline anisotropies axis of FM layer.