Perpendicular magnetic recording medium and method of manufacturing the same
US7875372B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 2007 |
| Grant date | Jan 25, 2011 |
| Priority date | — |
| Expiry date | Oct 2, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/82
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Embodiments of the present invention help to improve corrosion resistance and durability by providing a functional diamond like carbon (DLC) protective layer for a perpendicular magnetic recording medium using a granular magnetic layer. According to one embodiment, when a DLC protective layer that protects a granular magnetic layer of a perpendicular magnetic recording medium is formed using a CVD method, the thickness of a first layer on the granular magnetic layer is set to 7.5 to 25% of the total thickness of the protective layer and a hydrogen content of the first layer is set to 33 to 38%, the thickness of a second layer is set to 50 to 85% of the total thickness of the protective layer and a nitrogen content of the second layer is set to 3 to 7%, and the thickness of a third layer located at the outermost side of the protective layer is set to 7.5 to 25% of the total thickness of the protective layer and a hydrogen content of the third layer is set to 25% or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.