Abstract
The formation of the high-Tc phase and the electrical property have been studied for the Pb-rich sample with a nominal composition of Bi:Pb:Sr:Ca:Cu=0.726:0.374:1.0:1.0:1.65 sintered at temperature range between 840 and 853°C. The sample calcined at 800°C for 12h consists of a large amount of Ca2PbO4 and CuO beside the low-Tc phase. The low-Tc phase increases rapidly in an early stage of sintering and then decreases through a maximum as sintering is extended. On the other hand, the high-Tc phase increases much gradually in comparison with that in the Pb-poor sample of Bi:Pb:Sr:Ca:Cu=0.96:0.24:1.0:1.1:1.6 reported previously. The samples sintered in the temperature range from 845 to 853-C show Tc of about 110K, independent of sintering temperature.
