Patent ID: 7132176

Claim:
A perpendicular magnetic recording medium comprising: a nonmagnetic substrate; a first perpendicular magnetic recording layer formed on the nonmagnetic substrate at room temperature, wherein the first perpendicular magnetic recording layer has an easy axis of magnetization in a vertical direction, and contains cobalt, oxygen, and at least one of platinum and chromium; a second perpendicular magnetic recording layer formed on the first perpendicular magnetic recording layer at room temperature, wherein the second perpendicular magnetic recording layer has an easy axis of magnetization in the vertical direction, and mainly contains a crystalline alloy, and the crystalline alloy consists essentially of cobalt, chromium, platinum, and optionally one or both tantalum and niobium, and at least one rare earth element selected from the group consisting of yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, thulium, ytterbiu and lutetium, and one of a lubricating layer and a protective layer.