Hysteresis gain-to-loss-ratio measurements

The degree of confinement of the magnetic easy axis parallel or perpendicular to the film plane plays a crucial role in both longitudinal and perpendicular recording media. In this paper, we demonstrate a versatile technique for the determination of magnetic orientation distributions based upon a distinct hysteresis anomaly that occurs near the hard magnetic axis. Here, one observes areas of energy gain in addition to the conventional hysteretic energy loss. The ratio of energy gain to loss increases with better definition of the easy axes and can therefore be utilized as its quantitative measure. In addition, we compare our experimental results to calculations of this anomaly based upon the Stoner-Wohlfarth model.