Perpendicular magnetic recording disk having a permeability gradient
US8982510B2 · kind B2 · utility
0Cited by
9References
25Claims
0Family size
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Inventor
Key dates
| Filing date | Nov 5, 2007 |
| Grant date | Mar 17, 2015 |
| Priority date | — |
| Expiry date | Jul 31, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/7368
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Perpendicular magnetic recording disks and methods of fabricating perpendicular magnetic recording disks are described. The perpendicular magnetic recording disk includes a soft magnetic underlayer (SUL) structure, an interlayer, and a perpendicular magnetic recording layer. The SUL structure has an increased permeability from an inner radius of the disk to an outer radius of the disk. As a result, the magnetic write width (MWW) on the tracks of the disk is substantially uniform throughout the disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.