Effect of Li Addition to the Low-Tc Phase in the Bi-Sr-Ca-Cu-O system (II)

The effect of Li addition to the low-Tc phase in Bi-Sr-Ca-Cu-O system has been studied for the samples with nominal compositions of Bi:Sr:Ca:Cu:Li=2:3-y:y:2:x(x=0 to 0.6, y=1.25, 1.5, 2.0) heated at 600 to 760°C for 12 to 48h in air. The Li addition promotes the formation of the low-Tc phase. Monophasic samples of the low-Tc phase were obtained for x=0.2 to 0.6 by heating at remarkably lower temperatures. The lattice constant c of the low-Tc phase depends on y as well as Li content. As the heating time extends, the Li content in the low-Tc phase decreases. For y=1.25 and 1.5 c increases as the Li content increases. On the contrary, c for y=2.0 decreases as the Li content increases.