Magnetic recording medium having a specific relation of coercive force HC and residual magnetization MR in perpendicular direction to substrate surface
US7038873B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 2003 |
| Grant date | May 2, 2006 |
| Priority date | — |
| Expiry date | Dec 30, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0021
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A perpendicular magnetic recording medium has a substrate, a magnetic functional layer provided on the substrate, and a magnetic recording layer stacked in contact with the magnetic functional layer and having perpendicular magnetic anisotropy. −4×2πMs2≦Ku≦6×2πMs2 is satisfied, wherein Ku represents a perpendicular magnetic anisotropy constant of the magnetic functional layer and Ms represents a saturation magnetization. The magnetic moment of the magnetic functional layer is rotated in a direction of an applied magnetic field during the recording, and the magnetic moment acts on the magnetization of the recording layer in such a manner that the applied magnetic field is assisted thereby. Minute magnetic domains can be stably retained and excellent thermal disturbance resistance can be obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.