Magnetic recording medium having a secondary recording layer made of a material having a negative crystal magnetic anisotropy and magnetic recording and reproducing apparatus
US8116035B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 9, 2006 |
| Grant date | Feb 14, 2012 |
| Priority date | — |
| Expiry date | Jun 12, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F10/16
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention provides a magnetic recording medium, and a magnetic recording and reproducing apparatus. The magnetic recording medium includes a substrate 11, an under layer 12 formed on the substrate 11, a magnetic recording layer 13 formed on the under layer 12, and a protective layer 14 formed on the magnetic recording layer 13. The magnetic recording layer 13 is composed of a primary recording layer 14 and a secondary recording layer 15 which are mutually exchange-coupled. The primary recording layer 14 has magnetic grains and a nonmagnetic material that surrounds the magnetic grains, and has a perpendicular magnetic anisotropy. The secondary recording layer 15 is made of a material having a negative crystal magnetic anisotropy and its easy plane of the magnetization is a plane of the medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.