Patent ID: 6699600
Filing Date: 2004-03-02
Classification: G11B

Abstract:
A magnetic recording medium comprising: on a non-magnetic substrate,at least a soft magnetic undercoat film comprising a soft magnetic material; an orientation control film for controlling an orientation of a film directly above; a perpendicular magnetic film in which an axis of easy magnetization is oriented mainly perpendicularly with respect to the substrate; and a protection film, wherein the perpendicular magnetic film has a structure in which a large number of magnetic grains are separated by a grain boundary layer, and an average separating distance between the magnetic grains along a straight line which connects centers of gravity of mutually neighboring magnetic grains is 1 nm or greater, and wherein the perpendicular magnetic film comprises Co and Cr, and when a Cr concentration in the magnetic grains is c1, and a Cr concentration in the grain boundary layer is c2, c2/c1 is 1.4 or greater.