Hexagonal ferrite magnets
US6248253A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1999 |
| Grant date | Jun 19, 2001 |
| Priority date | — |
| Expiry date | Mar 19, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/2641
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An object of the invention is to simultaneously increase the saturation magnetization and magnetic anisotropy of M type ferrite, thereby realizing a hexagonal ferrite magnet having a high remanence and high coercivity which could never be achieved in prior art M type hexagonal ferrite magnets. The object is attained by a hexagonal ferrite magnet comprising A, R, and Fe, wherein A represents at least one element selected from among Sr, Ba, and Ca, and R represents an element capable of assuming a valence of +3 or +4 and having an ionic radius of at least 1.00 angstrom, and n/N is up to 0.35 provided that N is the total number of crystal grains and n is the number of crystal grains having stacking faults.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.