Ferromagnetic resonance and stress anisotropy in a ferromagnetic/antiferromagnetic bilayer

We study the ferromagnetic resonance (FMR) on a system consisting of a ferromagnetic (FM) film and an antiferromagnetic film. The FMR frequency and its linewidth were derived analytically and calculated numerically as a function of applied magnetic field and its angle, exchange anisotropy, strength, and angle of the stress anisotropy for single crystal FM films with, respectively, uniaxial or cubic magnetocrystalline anisotropies. The results show that the system with an applied or residual stress anisotropy has some symmetrical, or equivalent, directions of the hard and easy axes. This property is always destroyed by the asymmetrical shift caused by the exchange anisotropy. This fact will be helpful to the experimentalist in distinguishing between the stress and the exchange anisotropies.