Process for the synthesis of crystalline powders of perovskite compounds
US5900223A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1996 |
| Grant date | May 4, 1999 |
| Priority date | — |
| Expiry date | Nov 14, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/776
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for the preparation of crystalline perovskite powders consisting essentially of primary particles uniform in nanometer or micrometer size and uniform and near spherical shape and of narrow size distribution, of the general formula A.sub.x (BO.sub.3).sub.y, wherein cation A is at least one metal selected from the group comprising Li.sup.+, Na.sup.+, K.sup.+, Mg.sup.2+, Ca.sup.2+, Sr.sup.2+, Ba.sup.2+ and La.sup.3+ and B in the anion (BO.sub.3) is at least one metal selected from the group consisting of Ti.sup.4+, Zr.sup.4+, Sn.sup.4+, Hf.sup.4+, Nb.sup.5+ and Ta.sup.5+, x is equal to the valence of the anion (BO.sub.3) and y is equal to the valence of cation (A), comprising contacting, under stirring, an aqueous solution (I) containing inorganic or organic salts or organometallic compounds of at least one metal A and of at least one metal B, the ratio (A)/(B) being around the stoichiometric value corresponding to the above general formula, with an aqueous basic solution (II) containing an inorganic or organic base in an amount at least above the stoichiometric amount corresponding to the above general formula, preheated to 70.degree.-100.degree. C., and performing the proc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.