| 摘要 |
A perpendicular magnetic recording medium, which includes a nonmagnetic substrate, and a first underlayer in the form of 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. The SUL has a plurality of SUL layers including a type-A SUL layer, 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. The type-A SUL layer may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb. Each of the type-B SUL layers is in antiferromagnetic coupling, and may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb. |
| 主权项 |
1. 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, andthe type-A SUL layer further includes V, and each of the type-B SUL layers is free of V. |
