Recorded magnetisation distributions in thin film media

The nature of magnetization distributions written into thin film recording media is described, with particular attention focused on the form of sawtooth magnetization patterns in longitudinal recording. The implications of these distributions are considered in detail and related to attainable packing densities and the hysteresis properties of the recording media. Transition widths for sawtooth type transitions are predicted which appear to agree, at least qualitatively, with experimental observations, and depend strongly on medium hysteresis and head properties. It is shown that the shapes of recorded transitions play a strong role in determining the packing-density-related aspects of recording performance, perhaps more than hitherto recognized. The shapes of the recorded transitions in thin metal films where sawtooth structures are known to exist are related not only to (M_rD/H _c) but also the slopes of the sides of the hysteresis loops and to record head field gradient