| 摘要 |
PURPOSE:To obtain a powdery starting material capable of providing a rare earth element - alkaline earth element - Cu type high temp. oxide superconductor having high density and high critical current density by precalcining a coprecipitate obtd. by using a specified precipitant. CONSTITUTION:A precipitate is formed by allowing a mixed soln. contg. a rare earth element salt. an alkaline earth element salt, and a Cu salt to contact with a mixed soln. of an ammonium salt and an amine compd. The precipitate is separated by filtration after washing with water or without washing with water, and dried and precalcined. Suitable salts of the above described elements are chlorides, nitrates, etc. Suitable ammonium salts are carbonates, bicarbonates, etc. Suitable amt. thereof to be used is equimolar amt. to the amt. of alkaline earth element salt. Suitable amine compds. are primary, secondary, and tertiary amine compd., but, particulary, secondary amine compds. (R2NH; wherein R is 1-4C alkyl) are preferred. Suitable amt. thereof to be used is >=1.5 times for the amt. of the Cu salt. |
