Perpendicular magnetic recording medium, method of evaluating magnetic properties of the same
US7457064B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 2007 |
| Grant date | Nov 25, 2008 |
| Priority date | — |
| Expiry date | Jun 11, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/1278
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Embodiments in accordance with the present invention provide a perpendicular magnetic recording medium which is easy to record, offers superior thermal stability of recording magnetization, and allows high-density recording. In one embodiment, a perpendicular magnetic layer with controlled magnetic properties is used as a magnetic storage layer of a perpendicular magnetic recording medium, the magnetic properties having been controlled such that an indicator σhsw [%] of the dispersion of magnetization switching fields in the perpendicular magnetic layer and an indicator Dn [nm] of the intensity of exchange interactions, in film surface directions, in the perpendicular magnetic layer satisfy inequalities σhsw/27+Dn/90<1, and Dn>20. The indicators can be measured using a magnetometer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.