DISTRIBUTION OF ANISOTROPY-FIELD IN RECORDING MEDIA DEDUCED FROM THE HYSTERESIS CURVE

The distribution of anisotropy fields in magnetic recording media is c arried out by performing the second derivative of the magnetization cu rve detected in perpendicular direction with respect to the easy axis of the system, following a procedure similar to that used for the soft magnetic materials. The method is applied to the CoCr films with the anisotropy direction perpendicular to the film plane. It was found tha t the field at the peak of the distribution function agrees with the a nisotropy field measured by the torque method. For particulate media,t he shape of the anisotropy distribution function depends both on the p article orientation ratio and on the interparticle interactions; as a consequence, the anisotropy distribution function determined on these materials does not represent the intrinsic anisotropy field distributi on of the particles but the anisotropy distribution as it appears in t hat particular specimen. In any case, this function is useful for unde rstanding the magnetic behavior of the system. (C) 1997 American Insti tute of Physics.