Magnetic recording medium comprising multiple thin film magnetic layers each formed within specified maximum and minimum incident angles
US5225234A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 2, 1991 |
| Grant date | Jul 6, 1993 |
| Priority date | — |
| Expiry date | May 2, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium of the longitudinal recording type is comprised of a magnetic layer on one major surface of a non-magnetic substrate wherein the magnetic layer consists of at least two layers of cobalt-based ferromagnetic metal thin film which are formed by oblique evaporation at an incident angle varying between a maximum .theta.max and a minimum .theta.min. Assuming that the layers disposed close to and remote from the substrate are designated lowermost and uppermost layers, respectively, the lowermost layer of ferromagnetic metal thin film is deposited at a smaller .theta.max value than is the uppermost layer of ferromagnetic metal thin film. The uppermost layer is deposited at a greater .theta.min value than is the lowermost layer. The medium is improved in corrosion resistance and electromagnetic properties properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.