Switching mechanism of Co-Cr films with Ge underlayer

The switching mechanism of a highly oriented Co-Cr single layer film with a Ge underlayer was investigated by measuring R/W characteristics, observing the Bitter pattern of recorded magnetization and head field calculation by finite element method. To clarify the relationship between magnetization reversal and head field intensity, overwrite signal to noise ratio and asymmetry ratio of two adjacent hits output amplitude were measured. To analyze the switching mode of this film, Bitter patterns of the recorded medium on the top and the bottom surfaces with different write currents were observed. From these results, it is concluded: (1) Complete magnetization reversal can be achieved when the head field in the perpendicular direction is greater than × 1.2 at the bottom of the Co-Cr layer. (2) This film is easily magnetized through the direction of depth, but degradation of the perpendicular head field distribution affects perpendicular magnetization penetration.