Patent ID: 7645528
Filing Date: 2010-01-12
Classification: G11B

Abstract:
1. A magnetic recording medium comprising: a substrate; an underlayer formed on the substrate; a first ferromagnetic layer formed on the underlayer; a nonmagnetic layer formed on the first ferromagnetic layer; a second ferromagnetic layer formed on the nonmagnetic layer; and a third ferromagnetic layer formed on the second ferromagnetic layer, the first ferromagnetic layer and the second ferromagnetic layer being antiferromagnetically coupled via the nonmagnetic layer, the second ferromagnetic layer and the third ferromagnetic layer being ferromagnetically coupled, wherein, where the saturation magnetization of the first ferromagnetic layer is M t t and, the value t wherein the film thickness of the third ferromagnetic layer is thinner than the film thickness of the second ferromagnetic layer; wherein the ratio of the saturation magnetization M