Density and phase dependence of edge erase band in MR/thin film head recording

The erase band resulting from edge overwrite has been studied using magnetic force microscopy. Utilizing image processing techniques, we developed a method to accurately measure the width of the edge erase band. In this paper, we focus on the study of MR/thin film head recording. Our experimental results show the erase band width is strongly dependent on the relative phase of the transitions in the old and new tracks at low bit densities. As the recording density is increased, the erase band width increases and becomes independent of the phase change. The erase band width observed ranges from 0 to 0.7 μm for a typical MR/thin film head with 4 μm wide trailing pole