Patent ID: 6821653
Filing Date: 2004-11-23
Classification: G11B,Y10T

Abstract:
A magnetic recording medium comprising, in order, a non-metallic substrate having texture grooves having a line density of 7,500 lines/mm or more on its surface; an orientation-determining film; a non-magnetic undercoat layer; and a magnetic layers;wherein the magnetic layer has a magnetic anisotropic index (OR) of 1.05 or more; wherein OR&boxH;Hc in a circumferential direction/Hc in a radial direction; wherein the orientation-determining film comprises at least one alloy selected from the group consisting of a Cr alloy, NiB, NiP, and NiPZ; wherein Z is one or more elements selected from the group consisting of Cr, Mo, Si, Mn, W, Nb, Ti and Zr; and wherein the surface of the orientation-determining film has been exposed to an oxygen atmosphere.