Compositions of particulate magnetic oxides with a defect spinel structure, preparation thereof and application thereof
US4808327A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 1, 1987 |
| Grant date | Feb 28, 1989 |
| Priority date | — |
| Expiry date | Jun 1, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/42
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Particulate magnetic oxide compositions based on iron oxide (III) and oxide of at least one bivalent metal selected among cobalt, iron, copper, zinc, magnesium, nickel, manganese and cadmium, characterized in that said compositions contain additionally in the form of an oxide from 0.2 to 5% by weight calculated on the total weight at least one additive or substituent selected among alkali metals, alkaline-earth metals, boron, the elements of columns 3, 4 and 5 of the periodical classification of elements having a molecular mass higher than 26, the transition metals 3d and 4d other than those already mentioned, and the rare earths, with the proviso that when an alkali metal or tin is present, at least another additive or substituent is also present, and in that said compositions have a structure of the lanucar spinel type; the preparation and application thereof are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.