Magnetic recording medium for perpendicular magnetic recording
US7901802B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 2007 |
| Grant date | Mar 8, 2011 |
| Priority date | — |
| Expiry date | Mar 28, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/678
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A perpendicular recording medium having a perpendicular magnetic recording layer and a magnetically soft underlayer structure disposed beneath the recording layer. The soft underlayer structure includes at least first and second soft magnetic layers having different magnetic permeabilities to create a magnetic permeability gradient in the soft underlayer structure. One or more of the soft magnetic layers can be anti-parallel coupled. The soft underlayer structure of the present invention having a magnetic permeability gradient advantageously leads to reduced adjacent track erasure (ATE) while maintaining good overwrite (OW) properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.