Perpendicular magnetic recording medium and manufacturing of the same
US7625644B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 2005 |
| Grant date | Dec 1, 2009 |
| Priority date | — |
| Expiry date | Jun 6, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/851
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a granular magnetic recording layer of a perpendicular magnetic recording medium, media noises are reduced by separating adequately magnetic crystal grains and non-magnetic grain boundary and decreasing magnetic exchange interactions among the magnetic crystal grains without causing damage to magnetic anisotropy of the magnetic crystal grains. In one embodiment, the perpendicular magnetic recording medium, in which crystal alloy grains containing Co, Pt, and Cr, and non-magnetic grain boundary containing Si and O is included; the ratio of the number of O atom to that of Si atom in the magnetic recording layer is between about 2.5 and 5; the Si atomic composition in the magnetic recording layer is between about 3 and 6 atomic %; and the O atomic composition in the magnetic recording layer is between about 12 and 20 atomic %, is used. The in-plane distribution of perpendicular coercivity at any points of the medium of the magnetic recording layer is made at most about ±10% of an average value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.