Perpendicular magnetic recording medium and magnetic storage apparatus using the same
US7701667B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 2007 |
| Grant date | Apr 20, 2010 |
| Priority date | — |
| Expiry date | Jan 11, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/672
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Embodiments in accordance with the present invention provide a perpendicular recording medium with low noise and high recording density by reducing the effects from noise generated from the vicinity of the interface with the intermediate layer of the recording layer, in a perpendicular recording medium utilizing a granular recording layer containing oxygen or oxide additive in a cobalt-chromium alloy formed on an intermediate layer with a ruthenium or ruthenium alloy layer. A first recording layer and a second recording layer are formed in order on an intermediate layer of ruthenium or ruthenium alloy. The first recording layer and the second recording layer are comprised of cobalt as the main material in a granular structure containing chromium and oxygen. The saturation magnetization of the first recording layer is lower than the saturation magnetization of the second recording layer. When a first recording layer saturation magnetization is set as Ms1(emu per cubic centimeter), a second recording layer saturation magnetization is set as Ms2(emu per cubic centimeter), and the first recording layer film thickness is set to t1 (nm), then (Ms2−Ms1)×t1 will be larger than 0 (memu per …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.