Corners and nucleation in micromagnetics

The divergence of the stray field in corners and its consequence for micromagnetic calculations was studied numerically in two dimensions for high-anisotropy materials. The results show that no atomistic theory has to be invoked because the singularity is smoothed out already within micromagnetics. The magnetic configurations and its deduced critical quantity, the coercivity, are determined correctly if the configurations are well approximated on the exchange length SQRT(A/Kd). The singularity in the stray field remains only visible in the torque balance where it is compensated by an exchange torque.