Baseline Shift of Perpendicular Single-Layered Media and Perpendicular/Longitudinal Composite Media.

The baseline shift of perpendicular single-layered media and perpendicular-longitudinal composite media was investigated. A baseline shift was observed for both the perpendicular single-layered media and the composite media, but the extent of the shift decreased with increasing underlayer coercivity for the composite media. From the off-track profile and MFM observation, the baseline shift is considered to be caused by the remanent magnetization state around the track edge for these media. The decrease in the baseline shift with increasing underlayer coercivity for the composite media is likely to be related to the writability of these media, and it might cause a change in the remanent magnetization state around the track edge.