PROCESS FOR PRODUCING A HIGH-TEMPERATURE SUPERCONDUCTOR CONTAINING BISMUTH, STRONTIUM, CALCIUM AND COPPER

摘要

The invention relates to a process for producing a bismuth-, copper-, strontium- and calcium-containing high-temperature superconductor, in which an aqueous solution is produced which has a pH of 0.5-4 and which contains the metals in an atomic ratio corresponding to a high-temperature superconductor, the solution is combined with an oxalic acid solution to precipitate the metals quantitatively as oxalates, the oxalates formed are separated off and decomposed thermally to form the oxides and the latter are reacted in the presence of oxygen at temperatures above 700 DEG C. to form the desired high-temperature superconductor. The process comprises concentrating the aqueous solution of the metal until a precipitate begins to appear and using the oxalic acid as a solution in an organic solvent which is miscible with water The oxalates are decomposed at 550-700 DEG C. in the presence of oxygen.