Perpendicular magnetic recording media with magnetic anisotropy/coercivity gradient and local exchange coupling
US7846564B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 2005 |
| Grant date | Dec 7, 2010 |
| Priority date | — |
| Expiry date | Aug 27, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic anisotropy field Hk extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.