Patent ID: 8247094

Claim:
A perpendicular magnetic recording medium comprising a nonmagnetic substrate, and at least a soft magnetic layer (SUL), an alignment control layer, a magnetic recording layer and a protective layer formed on the nonmagnetic substrate; wherein the magnetic recording layer is constituted of three or more layers and includes a first magnetic recording layer, a second magnetic recording layer and a third magnetic recording layer from the substrate side, and includes an exchange coupling control layer for exchange coupling of both layers between the first magnetic recording layer and the second magnetic recording layer, and also includes an exchange coupling reduction layer for reducing exchange coupling of both layers between the second magnetic recording layer and the third magnetic recording layer and, regarding magnetocrystalline anisotropic energy K u of each magnetic recording layer, the first magnetic recording layer has 4×10 6 erg/cc or higher, the second magnetic recording layer has 2×10 6 erg/cc or lower, the third magnetic recording layer has 1×10 6 erg/cc or lower, and K u of the second magnetic recording layer is higher than that of the third magnetic recording layer.