EFFECTS OF SINTERING CONDITION ON THE SUPERCONDUCTING AND MICROSTRUCTURAL PROPERTIES OF BI-PB-SR-CA-CU-O MATERIALS

The effects of sintering condition on the superconducting properties o f Bi1.7Pb0.3Sr1.6Ca2.4Cu3.6Oy bulk materials were studied. Results ind icated that the decomposition of the high-T-c phase was found when sam ples were sintered at 840-859 degrees C. The low-T-c phase and non-sup erconducting phases such as CuO, CaO, Ca2PbO4, and (Sr,Ca)(2)CuO3 were found to be in these samples. However, the high-T-c phase could be re covered by two-step sintering process. It was also observed that the c ritical current density of the BPSCCO pellets was strongly improved by this two-step heating process. The relationships between the microstr uctural and superconducting properties were also discussed.