Switching behaviour of interacting magnetic particles

The magnetostatic properties of particulate magnetic media depend strongly on the packing density because of the magnetic interactions of the particles. To investigate the influence of these interactions we considered two models. One was a dipole model consisting of anisotropic dipoles and dealing with only one component of the magnetic moment. The other model consisted of two interacting Stoner-Wohlfarth particles, where the magnetic moments might rotate. We observed that in the latter model the coercive force decreases under practical conditions with the strength of the interaction, while in the first model it increases.