Sharp transitions in perpendicular recording

A simple continuum model and a discrete model are proposed in order to examine the issue of the existence of sharp transitions in perpendicular recording. Both approaches, even though fundamentally different, give a range of material parameters where transition sharpness is limited only by exchange. In the discrete model the head field gradient determines the sharpness of an isolated transition. However, when a periodic pattern is considered the optimization of the head depends critically on the density and magnetization regime.