Magnetic recording medium comprising a ferromagnetic metal film and two carbon protective layers
US5364690A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 1992 |
| Grant date | Nov 15, 1994 |
| Priority date | — |
| Expiry date | Oct 22, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/30
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium comprising: a non-magnetic substrate; a ferromagnetic metal thin film provided on the non-magnetic substrate; a filmlike first carbon layer provided on the ferromagnetic metal thin film; and a hard and amorphous second carbon layer provided on the first carbon layer; the first and second carbon layers having first and second Raman spectra based on Raman spectrophotometry, respectively; assuming that when each of the first and second Raman spectra is decomposed into a first band of Gaussian function having a peak in the vicinity of 1380 cm.sup.-1 and a second band of Gaussian function having a peak in the vicinity of 1550 cm.sup.-1 in X-Y rectangular coordinates with an X-axis expressed in cm.sup.-1 and a Y-axis indicative of spectral intensity, a ratio of an area enclosed by the first band and the X-axis to an area enclosed by the second band and the X-axis represents "relative intensity", the first carbon layer has a relative intensity of 2 to 20, while the second carbon layer has a relative intensity of 0.8 to 3, a Vickers hardness of not less than 1,000 kg/mm.sup.2 and a thickness of 50 to 300 .ANG..
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.