Behavior of Soft Magnetic Backlayer in Recording and Reproducing Process on Perpendicular Magnetic Recording Media

Double layered Co-Cr perpendicular recording media were studied with respect to effect of a Ti thin intermediate layer between the Co-Cr and Ni-Fe layers on recording and reproducing characteristics. The increase of the output voltage by introduction of the Ti layer was explained by the increase of the effective permeability of the total system of the perpendicular head and back layer of the D.L. medium. It was found that the highly permeable back layer achieved by using the Ti layer induces a broadened waveform and an increase of peakshift of reproduced pulses. We concluded that media without a Ti layer are superior to those with a Ti layer with respect to the recording resolution.