Intrinsic anisotropy-defined magnetization reversal in submicron ring magnets

The influence of magnetocrystalline anisotropy in the magnetization reversal of submicron Co rings was studied. The magneto-optical Kerr effect (MOKE) magnetometry and magnetic force microscopy (MFM) combined with numerical micromagnetic simulations were used for the study. It was found by micromagnetic simulations that the magnetization reversal process of the rings started from a buckling-like reverse domain nucleation, followed by local vortex formation and an avalanche process of local vortex nucleation.