Numerical micromagnetics: rectangular parallelopipeds

Results of simulations of magnetization reversal in rectangular Permalloy particles with aspect ratios 10×5×1 are given. Magnetization patterns during nucleation of reversal in the remanent state and after the applied field is reversed are shown in detail for the case of an applied field along the long axis of the particle. The nucleation and remanent state behaviors are also illustrated in lesser detail for other applied field directions. The remanent state is the classical four-domain pattern, although the seven-domain pattern also appears. The longest wall in the four-domain pattern is a vortex wall