Fast reversal dynamics of disk media (perpendicular and longitudinal)

A dynamic micromagnetic model of granular thin film magnetic recording media has been employed to study the reversal modes of longitudinal and perpendicular thin films. Different reversal modes can be produced by using vector applied fields which either rotate or are applied off axis. When axial fields are applied the reversal of grains is incoherent, with an interaction energy barrier, high coercivity, long dynamic reversal times, and behavior characteristic of heavy damping. In contrast, for rotational fields in longitudinal media and for off-axis fields in perpendicular media the reversal is coherent, with a reduced energy barrier, lower coercivity, fast dynamic reversal, and behavior characteristic of light damping. (C) 2002 American Institute of Physics.