Demonstration of 35 Gbits/in/sup 2/ in media on glass substrates

Abstract

A recording density of 35 Gbits/in/sup 2/ was achieved in longitudinal recording media with high-sensitivity GMR heads. The media displayed excellent thermal stability as a result of a CoPtCrB alloy with high magnetocrystalline anisotropy and relatively narrow grain size distribution. The degree of Co easy-axis orientation in the plane of the /spl mu/m was greatly improved and the grain size was reduced in the media on glass substrates. Estimates of the switching volume from dynamic coercivity and signal-to-noise measurements are larger than the physical grain size, suggesting that intergranular interactions improve stability. A potential path to further increases in recording density above 35 Gbits/in/sup 2/ is to use antiferromagnetically coupled magnetic layers in the media.