Magnetic recording medium, magnetic recording medium manufacturing method, and magnetic disk
US8076013B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 2008 |
| Grant date | Dec 13, 2011 |
| Priority date | — |
| Expiry date | Apr 17, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/855
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium (10) has a substrate (12) and a perpendicular magnetic recording layer (30) formed over the substrate (12). The perpendicular magnetic recording layer (30) has a granular layer (20) in which a magnetic signal is recorded and a continuous film layer (24) magnetically coupled to the granular layer (20). The continuous film layer (24) has hard magnetic portions (204) formed in positions corresponding to the recording regions where magnetic signals are recorded in the granular layer (20) and magnetic shield portions (202) formed between the hard magnetic portions (204), each having a magnetization curve whose slope is larger than those of the hard magnetic portions in the region where the applied magnetic filed is zero when the magnetization curve is measured, and each having a residual magnetic polarization smaller than those in the hard magnetic portions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.