Co-Cr COMPOSITE MEDIA INTENDED FOR PERPENDICULAR MAGNETIC RECORDING BY USING A RING-TYPE HEAD

Abstract

A Co-Cr double layer medium, with a very thin back layer, was investigated to improve recording performances in perpendicular recording when using a ring head. A very thin (only 100 Å) semi-hard back layer with high Bs has been shown to not only dramatically increase the reproduced output, but also to increase recording sensitivity. The preferred reproduced waveform, with a sharp single peak, has been obtained, showing a small peak shift as small as that seen for a single layer Co-Cr medium. We conclude that these improvements are due to reduced demagnetizing effects in the recording process rather than effects in the reproducing process. A design of this composite medium is also discussed.