Method to improve remanence-squareness-thickness-product and coercivity profiles in magnetic media
US7592079B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 2004 |
| Grant date | Sep 22, 2009 |
| Priority date | — |
| Expiry date | Jun 29, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/676
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic disk for information storage that includes a substrate and an information layer for containing information. The information layer includes a upper (e.g., recording) and lower (e.g., stabilizing) layers. The information layer has a remanence-squareness-thickness-product (“Mrt”) that varies radially between first and second disk radii. At least one of the following conditions is true: (i) the information layer has a coercivity that is at least substantially constant between the first and second disk radii; (ii) the lower magnetic layer has a magnetic anisotropy energy of no more than about 1.5×106 erg/cm3; and (iii) the magnetic anisotropy energy of the upper magnetic layer is at least about 150% of the magnetic anisotropy energy of the lower magnetic layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.