| 摘要 |
A perpendicular magnetic recording medium has a nonmagnetic substrate having concave portions and a soft magnetic layer on the nonmagnetic substrate. The depth of the concave portion and the thickness of the soft magnetic layer are larger than at least the length and the width of the concave portion such that the easy axis of magnetization in the regions of the soft magnetic layer in the concave portions is oriented perpendicular to the soft magnetic layer due to shape magnetic anisotropy. The easy axis of magnetization oriented perpendicular to the soft magnetic layer facilitates signal generation. The recording medium does not use the magnetization of the magnetic recording layer for such signal generation, which can be head positioning signals or other signals, such as copyright data. Instead, it uses the magnetization in the concave regions of the soft magnetic layer for such signal generation. |
