Micromagnetic studies of interacting Permalloy particles

Pairs of interacting Permalloy particles of submicron size have been studied using a micromagnetic code based on the finite element method. The hysteretic properties of the pairs are affected by both the placements and the separations between particles. Plateaus are found in the hysteresis loops of most pairs placed side by side or one on top of the other. They correspond to antiferromagnetically aligned states. Most pairs may be brought to a cross-tie wall state. It is found that cross-tie wall formation is affected by the shapes of the particles at the ends