Areal Density Potential for Non-Stoner-Wohlfarth Media

In composite media switching of magnetization takes place through domain wall reversal, rather than coherent rotation, characteristic of Stoner-Wohlfarth (S-W) media. The angular dependence of coercivity on applied field angle deviates significantly from the S-W astroid. A modified Williams-Comstock formalism is used to show how this angular dependence modifies the effective field gradient, hence the transition length. Analytical expressions are deduced to express the areal density potential of various media designs.