Electrical conductivity and superconductivity in (Bi–Pb)–Sr–Ca–Cu–O glass ceramics during the first minutes of crystallization

Abstract

(Bi 0.8Pb 0.2) 4Sr 3Ca 3Cu 4O x glass ceramic samples were obtained by annealing at temperatures between 700 and 870 °C for a short time. The measurements of the temperature dependence of resistivity in annealed samples were carried out with the conventional four-terminal method in a temperature range from 3 to 300 K. The dynamic changes of resistivity during the process of annealing were also monitored in some of the studied annealing temperatures. Low temperature resistivity measurements show that during the growth of crystalline phases a gradual change of conduction mechanism occurs. Some samples were superconducting with transition temperatures characteristic for (Bi 0.8Pb 0.2) 2Sr 2CuO x and (Bi 0.8Pb 0.2) 2Sr 2CaCu 2O x materials.