PREPARATION OF SUPERCONDUCTING-GRADE COPPER FROM COMMERCIAL GRADE COPPER SALT

Fine samples with nominal composition of Bi1.6Pb0.4Sr2Ca2Cu3Ox have be en produced by solid state method using various purity grades of start ing copper oxide powder. Studies on T-c and high-T-c volume fraction m easurements of these samples revealed that the samples produced using CuO powders obtained in laboratory after double purification of the co mmercially available copper salts have higher T-c (104.46 K) and incre ased percentage of high T-c volume fraction (58%) compared to even the samples prepared from Aldrich grade (99.99%) CuO. A simple and cost-e ffective chemical route for the purification of CuO from commercially available copper salts has been outlined.