Method for producing soft magnetic hexagonal ferrite sintered material and soft magnetic hexagonal ferrite sintered material
US7025946B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 21, 2002 |
| Grant date | Apr 11, 2006 |
| Priority date | — |
| Expiry date | Mar 21, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2237/704
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A soft hexagonal ferrite sintered material includes crystal particles of M-type hexagonal ferrite corresponding to a general chemical formula MFe12O19 wherein M is at least one element selected from the group consisting of Ba, Sr and Pb. Crystal particles having particle diameters of 5 μm to 100 μm are extracted from a sintered material produced from a precursor powder mixture. The extracted particles as seed crystals are mixed with a calcined powder comprising fine crystals having the above composition and particle diameters of 0.5 μm to 3 μm, then is sintered until the intended particle growth of the crystal particles in the sintered material is achieved to give an average particle diameter of 30 μm to 500 μm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.