INFLUENCE OF THE VARIATION OF THE HG AND PB STOICHIOMETRY ON THE MICROSTRUCTURE AND T-C OF HGXPBYBA2CA2CU3O8+DELTA

Samples of HgxPbyBa2Ca2Cu3O8+delta (1223) with x = 1.0, 1.2, 1.4 and y = 0, 0.1, 0.2, 0.3 were prepared by solid state method. The T-c of un doped 1223 was about 111 K after synthesis. After annealing in oxygen the T-c increased to 133 K. The T-c for Pb-doped samples depended slig htly on the Pb-content, for the as-prepared specimens were generally h igher than for undoped specimens and additional annealing did not sign ificantly change the T(c)s. Pb doping influences the shape of crystall ites. (C) 1997 Academic Press Limited.