Magnetic recording medium and process for producing the same
US4842917A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1987 |
| Grant date | Jun 27, 1989 |
| Priority date | — |
| Expiry date | Aug 24, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24355
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium having a magnetic film formed on a substrate directly or through an underlayer from an alloy containing Co as a principal component. The central line average surface roughness Ra and maximum surface roughness Rmax of the magnetic film in a direction perpendicular to the direction of magnetic recording are selected so as to fall within the ranges of 1 nm.ltoreq.Ra.ltoreq.20 nm and Rmax.ltoreq.25 Ra, respectively, and the in-plane magnetic anisotropy energy Ku of the magnetic film is selected to fall within the range of 0.ltoreq.Ku.ltoreq.8.times.10.sup.5 erg/cm.sup.3. Thus, it is possible to minimize the value of modulation which represents the degree of variation of read output on the same circumference of a magnetic disk. It is also possible to reduce the noise generated in read and write operations by forming the magnetic film so as have no crystallographic orientation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.