Abstract
Effects of the Li-addition to the high-Tc phase in the Bi-Pb-Sr-Ca-Cu-O system have been studied for samples with starting compositions of Bi:Pb:Sr:Ca:Cu:Li=0.9:0.2:1.0:1.0:1.6:x with x=0-0.10 and heated at 820-850°C for 40-96h. The temperature, at which an endothermic reaction occurred, lowered markedly as x increased. Tc was raised up to 116K for the sample with x=0.03 heated at 840°C for 48h, while a susceptibility measurement revealed that Tc=110K. The lattice constants, a and c, were independent of Li content. ICP analysis showed that the heat treated samples had very low Li content. The results suggest that a small amount of the high-Tc phase with Tc=116K forms on the surface of the high-Tc phase with Tc=110K.
