| 摘要 |
A perpendicular magnetic disk that includes, a base 110, a granular magnetic layer 160, and a auxiliary recording layer 180 disposed as an upper layer of the granular magnetic layer 160. The granular magnetic layer 160 has a granular structure in which a grain boundary portion is formed by segregation of a non-magnetic substance containing an oxide as a main component around magnetic particles containing a CoCrPt alloy grown in a columnar shape as a main component. The auxiliary recording layer 180 contains a CoCrPtRu alloy as a main component and has a film thickness of 1.5 nm to 4.0 nm. With this structure, the auxiliary recording layer can be thinned while maintaining the function thereof to improve SNR. |
