An Analysis of One Particle Per Bit Perpendicular Recording

In this paper, the particle characteristics which differ from those of the switching astroid of coherent rotation by allowing an easier mode of reversal in response to fields applied in directions close to the easy axes. Thus the critical switching distribution is an astroid cut off by a line at H = He crossing the easy axis. The required conditions and properties for single particle perpendicular recording at high densities are therefore for small head to medium spacings, particles with easy axes perpendicular to the media planes, an easy axis mode of reversal at fields less that the anisotropy field, and a low distribution of particle coercivities.