Magnet powder, sintered magnet, bonded magnet, and magnetic recording medium
US5846449A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 1996 |
| Grant date | Dec 8, 1998 |
| Priority date | — |
| Expiry date | Jul 25, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F10/205
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A magnet powder has a primary phase of hexagonal magnetoplumbite ferrite of the formula: A.sub.1-x R.sub.x (Fe.sub.12-y M.sub.y).sub.z O.sub.19 wherein A is Sr, Ba, Ca or Pb; R is Y, rare earth element or Bi (R essentially containing La); M is Zn or Cd; x, y, and z representative of a molar ratio are 0.04.ltoreq.x.ltoreq.0.45, 0.04.ltoreq.y.ltoreq.0.45, and 0.7.ltoreq.z.ltoreq.1.2. This ferrite is increased in saturation magnetization, offering a magnet having high remanence and maximum energy product. The magnet powder may be fired into a sintered magnet or bound into a bonded magnet. A magnetic recording medium comprising the magnet powder as a coating layer is provided as well as a magnetic recording medium comprising a thin film magnetic layer of the hexagonal magnetoplumbite ferrite.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.