Approximate Analysis of Perpendicular Magnetic Recording Characteristics

In perpendicular magnetic recording using a single pole type magnetic head and a double-layered medium, a sharp magnetization transition is formed in the Co-Cr layer of the medium because the demagnetizing field is minimized in the region of magnetization transition. Therefore, the shapes of isolated pulses can be easily calculated by a head field and a M-H loop of the medium. In this paper, a simple means of approximation for the analysis of an isolated pulse shape in perpendicular magnetic recording in described. For the analysis, the distribution of the head field is computed by FEM considering the head-to-medium magnetic interaction, and an actual M-H loop are used. The calculated narrow pulse width in perpendicular magnetic recording is compared with those measured and calculated in longitudinal magnetic recording.