Induced anisotropies in a ferromagnet coupled to a polycrystalline antiferromagnet
Résumé
The effect of thermal activation of a polycrystalline antiferromagnet (AF) coupled to a ferromagnet (FM) on the unidirectional anisotropy responsible for positive shift of the resonant frequency (fR) of the FM is presented. Hysteresis loops and ferromagnetic resonance plots of Co35Fe65/Ni50Mn50 are evaluated and matched with those obtained from experiments. The contribution of the AF magnetic structure to fR is highlighted. An inverse relation between fR and AF grain size is predicted.