Patent ID: 7169488
Filing Date: 2007-01-30
Classification: G11B

Abstract:
1. A granular perpendicular magnetic recording medium, comprising: a substrate; a surface treated granular magnetic layer formed over the substrate comprising a granular magnetic layer and a boundary layer comprising an oxide or a nitride of a component of the granular magnetic layer formed directly on the surface of the granular magnetic layer, wherein the granular magnetic layer has a granular structure comprising magnetic grains separated by grain boundaries, the grain boundaries comprising at least one of oxygen and nitrogen; and a protective overcoat formed over the surface treated granular magnetic layer, wherein the granular magnetic layer and the boundary layer comprises cobalt-based alloy comprising an oxide or a nitride and the protective overcoat comprises a carbon-containing overcoat, the carbon-containing overcoat having a thickness in the range of about 20 Å to about 70 Å, further comprising at least one interlayer, wherein the at least one interlayer comprises a first material selected from the group consisting of Ru, RuCr, and non-magnetic CoCr.