Micromagnetic calculation for superlattice magnetic recording media

A micromagnetic model with realistic grain configuration (planar Voronoi cells) is developed to simulate perpendicular magnetic recording media. The model is applied to an experimental Co/Pd superlattice film. The calculated perpendicular hysteresis loop exhibits a coercivity of 6560 Oe, in approximate agreement with the experimental value. It is found that the coercivity is largely invariant to grain irregularity, but the initial switching field depends greatly on grain size uniformity for ideally oriented material. In particular, an assumption of uniform grains produces a knee in the hysteresis loop that is not found with the more realistic Voronoi grains or in experiment. (C) 2000 American Institute of Physics. [S0021-8979(00)46008-1].