Abstract
It is necessary to understand phase equilibria in the Bi-system to effectively produce superconductors in this system. Experiments were performed using a quench method together with microscopic study as well as composition analyses by ICP and EPMA. Equilibrium phases at different temperatures were investigated and plotted on a quasi-binary temperature versus composition diagram between the nominal compositions Bi2 Sr2 Ca2 Cu3 Ox (2223, the high Tc phase) and Bi2 Sr2 Ca Cu2 Ox (2212, the low Tc phase). The liquidus temperature of the compound with the 2223 nominal composition found to be above 1100°C, and the primary solid phase formed to be Carich oxide. These results contradict those in previously reported phase diagrams, in which the temperature of the liquidus is about 1000°C. The liquidus lines along the composition axis as well as the primary phase coresponding to these lines Is also reported.
