PRODUCTION OF BI-ALKALINE EARTH ELEMENT-CU OXIDE BASED RAW MATERIAL POWDER OF SUPERCONDUCTING CERAMIC

摘要

PURPOSE:To obtain the title raw material powder of superconducting ceramic having easy sinterability, by calcining a mixed powder of a co-precipitate obtained by contact of solutions of Bi compound and alkaline earth element compound and a precipitant and Cu compound. CONSTITUTION:Some Bi compound and alkaline earth element compound comprising hydroxide, hydrochloride and organic acid salt, etc., are dissolved in a solvent such as water, alcohols and resultant solution is mixed with a solution of a precipitant such as caustic alkali, NH3, to obtain a co-precipitate containing Bi component and alkaline earth element component. Next, said co-precipitate is mixed with oxide of copper such as copper oxide or copper carbonate which is decomposed by heat and becomes copper oxide, etc. Resultant mixed powder is washed and dried in conventional method and is calcined at 500-900 deg.C to obtain raw material powder of Bi/alkaline earth element/Cu oxide based superconducting ceramic. Further, said raw material powder is molded under high pressure and sintered at 700-950 deg.C to afford superconducting ceramic.