Demagnetizing influence on a Stoner-Wohlfarth particle array

The effect of sheet demagnetizing on the classic Stoner-Wohlfarth particle is calculated. The model used is a two dimensional array of the Stoner-Wohlfarth particles with easy axis normal to the array plane. The particles are assumed to be decoupled except for sheet demagnetizing fields. Particles are assumed to be close enough together that volume average moment density can be used to compute the demagnetizing fields. Assuming there are two sub-ensembles of particles (one switched and one unswitched), an energy expression is found and both it and its derivatives are evaluated to determine the equilibrium magnetization orientations. The results, from an iterative calculation, are the sheared hysteresis loops. The sheared hysteresis loops are calculated for various angles of applied fields and for varying strengths of demagnetizing. In addition, an estimate of the rotational hysteresis parameter RHis made as a function of the strength of the demagnetizing fields.