Hydrothermal process for producing magnetoplumbitic ferrite
US4789494A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 1987 |
| Grant date | Dec 6, 1988 |
| Priority date | — |
| Expiry date | Jan 9, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/42
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
There is disclosed in hydrothermal process for producing a magnetoplumbitic ferrite powder of the formula: EQU MO.n(Fe.sub.2-x M'.sub.x O.sub.3) (1) wherein M is one or more metals selected from the group consisting of Ba, Sr, Ca and Pb; n is a number of 3 to 6; M' is at least one component selected from the group consisting of Si, Ta, Sb, Nb, Zr and Ti, or a combination of that component with at least one other component selected from the group consisting of Ni, Co, Cu, Mg, Mn and Zn; x is a number of 0.01 to 0.7, which process comprises carrying out the reaction of said ferrite powder formation in a H.sub.2 O medium at a temperature higher than 100.degree. C. and in the presence of an alkali having an alkali equivalent ratio greater than 1.0 with respect to an acid residue or in the presence of an alkali that provides the reaction system with a pH of 11 or more, said reaction being caused to proceed in the presence of "agent A" or in the present of both "agent A" and "agent B".
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.