Patent ID: 6913837

Claim:
A perpendicular magnetic recording medium, comprising: a nonmagnetic substrate; a soft magnetic under layer; an intermediate layer; a bilayer magnetic recording layer; a protective layer; and a liquid lubricant layer, wherein, according to a following order, the soft magnetic under layer, the intermedIate layer, the bilayer magnetic recording layer, the protective layer, and the liquid lubricant layer are sequentially stacked on the nonmagnetic substrate, and the bilayer magnetic recordIng layer comprises a first perpendicular magnetic layer comprising a CoCr alloy crystalline film, and a second perpendicular magnetic layer comprising a rare earth-transition metal alloy noncrystalline film, wherein the rare earth-transition metal alloy nonciystalline film comprises one of Pr, Nd, Gd, Dy, and Ho, wherein the CoCr alloy crystalline film has a film thickness of 10 nm to 30 nm, and the rare earth-transition metal alloy noncrystalline film has a film thickness of 2 nm to 15 nm, and wherein, when the film thickness of the CoCr alloy crystalline film is a, and the film thickness of the rare earth-transition metal alloy noncrystalline film is b, a film thickness ratio a/b is at least 2.