Characterization and phase transitions of (Bi,Pb)2Sr2Ca2Cu3Ox-Ag composite powder obtained by spray pyrolysis

DTA curve exhibited two strong endothermic peaks above 790 °C, one very wide with the onset at 790 °C and the second at 840 °C. In situ X-ray diffraction measurements strongly supported the view that the first endothermic peak was due to Ca2PbO4 decomposition and a transient liquid formation through PbO-CuO-Ag eutectic. The second endothermic peak can be explained by onset of Bi-2212 peritectic melting that began at 840 °C with local formation of Bi-2201 intergrowths. The melting was complete at 875 °C.