To continue the rapid increase of recording density, most observers believe the next generation of hard drives will use perpendicular media, in which the magnetization is perpendicular to the plane of the disk, rather than parallel as in existing "longitudinal" media.
We have simulated the switching process in a realistic thin film medium, whose material parameters are fit to the experimental hard axis loop.Here is a link to a 1.6 MB quicktime movie. It shows a 4x4 cell discretization of a section of an infinite thin film, with periodic boundary conditions.
A paper based on this work has been submitted to J. Appl. Physics, Feb. 2003.