Magnet powder, sintered magnet, process for producing them, bonded magnet, motor and magnetic recording medium
US6258290A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 13, 2000 |
| Grant date | Jul 10, 2001 |
| Priority date | — |
| Expiry date | Jun 13, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/113
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The magnetic powder and the sintered magnet of the invention contains a primary phase of a hexagonal ferrite containing A, Co or R wherein A represents Sr, Ba or Ca, and R represents at least one element which may be rare earth elements including Y, and Bi, and have at least two different Curie temperatures. wherein the two different Curie temperatures are present within a range of from 400 to 480.degree. C., and an absolute value of a difference therebetween is 5.degree. C. or more. As both the saturation magnetization and the magnetic anisotropy of the M type ferrite therein are increased, the magnetic powder and the wintered magnet have a high residual magnetic flux density and a high coercive force, which conventional M type ferrite magnets could not have, while having excellent temperature characteristics of coercive force.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.