Patent ID: 8895164

Claim:
A perpendicular magnetic recording medium, comprising: a nonmagnetic substrate; and a first underlayer formed as a soft magnetic under-layer (SUL), a second underlayer, an intermediate layer, a magnetic recording layer, a protective layer, and a lubricant layer sequentially laminated on the nonmagnetic substrate; wherein the SUL has a plurality of SUL layers including a type-A SUL layer being closest to the magnetic recording layer among the SUL layers, a plurality of type-B SUL layers including at least two adjacent type-B SUL layers, and a nonmagnetic metal spacer layer disposed between the two adjacent type-B SUL layers, wherein both the type-A SUL layer and each of the type-B SUL layers include a material selected from the group consisting of Co, Fe and Ni, and a material selected from the group consisting of W, Zr and Nb, and the type-A SUL layer further includes V, and each of the type-B SUL layers is free of V.