Magnetic powder for magnetic recording and magnetic recording medium containing the same
US5378547A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1992 |
| Grant date | Jan 3, 1995 |
| Priority date | — |
| Expiry date | Apr 16, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2982
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic powder for magnetic recording is disclosed which comprises composite type magnetic particles (A), each of which contains hexagonal ferrite and spinel structure ferrite, and single phase type magnetic particles of hexagonal ferrite (B). When the mixing ratio of (A) and (B) in the range from 5:95 to 95:5, remarkable effect can be obtained. Especially, when the mixing ratio of (A) and (B) is in the range from 5:95 to 30:70, the dispersion property is improved due to disturbance of magnetic stacking. Thus, the magnetic powder in this mixing ratio is particularly suitable for magnetic recording in a short wavelength range. When the mixing ratio of (A) and (B) is in the range 70: 30 to 95:5, the reproduction output is improved due to activation of (A) . Thus, the magnetic powder in this mixing ratio is specifically suitable for magnetic recording in a long wavelength range. By containing the magnetic powder described above, a perpendicular magnetic recording medium with high electromagnetic characteristics, particularly a high S/N ratio and a low noise can be obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.