Perpendicular magnetic recording medium
US4798765A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 1986 |
| Grant date | Jan 17, 1989 |
| Priority date | — |
| Expiry date | Mar 25, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31721
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A perpendicular magnetic recording medium comprises a recording medium base, a lower layer formed on the recording medium base, and an upper layer formed on the lower layer. The lower layer is made of a first material including cobalt, chromium and one or more elements other than cobalt and chromium. On the other hand, the upper layer is made of a second material including cobalt, chromium and one or more elements other than cobalt and chromium. A quantity of the one or more elements added to cobalt and chromium making up the second material is less than a quantity of the one or more elements added to cobalt and chromium making up the first material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.