Perpendicular magnetic recording media and magnetic storage apparatus using the same
US7618722B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 2008 |
| Grant date | Nov 17, 2009 |
| Priority date | — |
| Expiry date | Mar 27, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/737
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Embodiments of the invention provide a perpendicular magnetic recording medium that not only attains the magnetic isolation of crystal grains in a magnetic recording layer from one another in a region of the medium in which the thickness of an intermediate layer is equal to or smaller than about 20 nm but also exhibits excellent crystallographic texture and that exhibits small medium noise, excellent thermal stability, and high write-ability. In one embodiment, a perpendicular magnetic recording medium has at least a soft-magnetic underlayer, a first intermediate layer, a second intermediate layer, a third intermediate layer, and a magnetic recording layer successively formed on a substrate. The magnetic recording layer is composed of ferromagnetic crystal grains and oxides or nitrides, the third intermediate layer is composed of Ru or an Ru alloy, the second intermediate layer is composed of a metal or an alloy having the face-centered cubic lattice structure, and the first intermediate layer is composed of a metal or an alloy having the hexagonal close-packed structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.