Granular perpendicular media with surface treatment for improved magnetic properties and corrosion resistance
US7169488B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 2003 |
| Grant date | Jan 30, 2007 |
| Priority date | — |
| Expiry date | Nov 10, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0029
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A granular perpendicular magnetic recording medium having a surface treated magnetic layer comprising an oxidized or nitrogenized boundary layer formed on the surface of the magnetic layer, wherein the magnetic layer comprises granular magnetic regions having oxygen and/or nitrogen-containing grain boundaries. In one embodiment, the granular perpendicular recording medium further comprises a soft magnetic layer below the surface treated granular magnetic layer and a protective overcoat over the surface treated granular magnetic layer. A method of manufacturing a granular perpendicular magnetic recording medium includes depositing a magnetic layer having granular structure over a substrate and subsequently surface treating the granular magnetic layer in an oxygen and/or nitrogen-containing atmosphere to produce an oxidized and/or nitrogenized boundary layer formed on the surface of the granular magnetic layer. The granular perpendicular magnetic recording medium of the present invention exhibits high Hc and SNR while exhibiting improved corrosion resistance and contact start-stop performance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.