Process for the manufacture of polycrystalline garnet and corresponding monocrystals
US4350558A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 1980 |
| Grant date | Sep 21, 1982 |
| Priority date | — |
| Expiry date | Nov 7, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2004/50
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for the manufacture of a polycrystalline garnet containing aluminium and/or gallium and/or indium and at least one element taken from the group comprising the rare earths and yttrium, and to the corresponding monocrystal. The process comprises the following steps: PA0 (1) a solution containing the salts of the constituent cations of the garnet, in the proportions corresponding to the composition of the latter, is prepared; PA0 (2) corresponding hydroxides are co-precipitated by means of a base in order to obtain a co-hydroxide, the solution of salts and the base being added simultaneously at a temperature between ambient temperature and the boiling point of the solution of salts, in such a way that the pH of the medium is between about 5 and 10 and that, within these limits, it is kept at a constant value throughout the co-precipitation; PA0 (3) if appropriate, the co-hydroxide is left to age; PA0 (4) it is filtered off; PA0 (5) it is washed; PA0 (6) it is dried; and PA0 (7) it is then calcined at a temperature above the temperature for the formation of the desired garnet structure. The monocrystals obtained by Czochralski drawing of the polycrystalline garnets of the inv…
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