Corrosion resistant granular magnetic stack
US8728637B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 2010 |
| Grant date | May 20, 2014 |
| Priority date | — |
| Expiry date | Jan 13, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/672
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A corrosion-resistant granular magnetic recording medium with improved recording performance comprises a non-magnetic substrate having a surface; and a layer stack on the substrate surface, including, in order from the surface: a granular magnetic recording layer; an intermediate magnetic de-coupling layer; and a corrosion preventing magnetic cap layer. The intermediate magnetic de-coupling layer has an optimal thickness and/or composition for: (1) promoting magnetic exchange de-coupling between the granular magnetic recording layer and the magnetic cap layer; and (2) reducing the dynamic closure field (Hcl) for determining writeability and eraseability of the medium. Grain boundaries of the magnetic cap layer are substantially oxide-free, and have a greater density and lower average porosity and surface roughness than those of the granular magnetic recording layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.