Patent ID: 7989097
Filing Date: 2011-08-02
Classification: G11B

Abstract:
1. A magnetic recording medium comprising: a substrate; a first underlayer formed on the substrate and comprising an amorphous alloy containing Ni; a crystalline second underlayer formed on the first underlayer and comprising simple Cr or an alloy containing Cr; a nonmagnetic crystalline third underlayer formed on the second underlayer and comprising at least one element selected from the group consisting of Pt, Pd, Ag, Cu and Ir; and a magnetic recording layer formed on the third underlayer and comprising at least one element of Fe and Co and at least one element of Pt and Pd, and containing magnetic crystal grains having an L1 wherein an oxygen amount remaining on an upper surface of the second underlayer is larger than an oxygen amount remaining on a lower surface of the second underlayer, wherein the third underlayer contains crystal grains having a (100) plane oriented with a tilt angle in a range of 3 to 25° to a normal line to a medium plane, and wherein a normal line to a (001) plane of the magnetic crystal grains in the magnetic recording layer is oriented with a tilt angle in a range of 3 to 25° to a normal line to a medium plane.