Method of preparation of perovskite-type compounds
AssigneeHughes Aircraft Company
InventorsRicardo C. Pastor, Florentino V. Lee
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Abstract
The present invention relates to a low temperature method of preparing a compound of the formula: ABO.sub.3 wherein A=Ba, Sr, Ca and Pb; and B=Ti, Zr and Hf, by (a) reacting a B-alkoxide, with a predetermined amount of aqueous A-hydroxide, (b) heating the reaction mixture to an initial temperature of 100.degree. C.-250.degree. C. at 1-40 atmospheres of pressure; (c) cooling the reaction mixture and thereafter, heating it to a subsequent temperature of approximately 40.degree. C. to 60.degree. C.; (d) dialyzing the cooled reaction product and recovering the tenate.
Claims12
A low temperature method of preparing a compound of the formula:
- ABO.sub.3
- wherein
- A=Ba, Sr, Ca and Pb;
- and
- B=Ti, Zr and Hf,
- comprising the steps of:
- (a) reacting a B-alkoxide with at least a stoichiometric amount of aqueous A-hydroxide;
- (b) heating the reaction mixture to an initial temperature of 100.degree. C.-250.degree. C. at 1-40 atmospheres of pressure to form a reaction product;
- (c) cooling the reaction product to a temperature below 40.degree. C. and thereafter, heating it to a subsequent temperature of approximately 40.degree. C. to 60.degree. C.;
- (d) dialyzing the reaction product to form a dialyzate and a tenate and recovering the tenate.
A method of producing barium titanate comprising the steps of:
- (a) reacting titanium iso-butoxide with at least a stoichiometric amount of aqueous barium hydroxide;
- (b) heating the reaction mixture to an initial temperature of 100.degree. C.-250.degree. C. at 1-40 atmospheres of pressure to form a reaction product;
- (c) cooling the reaction product to a temperature of below 40.degree. C. and thereafter heating it to approximately 40.degree. C. to 60.degree. C.;
- (d) treating the reaction product with hydrochloric acid until a pH of 1-2 is attained;
- (e) dialyzing the reaction product into a dialyzate and tenate;
- (f) recovering the tenate and washing it with methylalcohol;
- and
- (g) drying the remaining residue.
Dependencies are inferred from the claim text.