Synthesis and Decomposition of the High-Tc Phase of a Pb-Doped Bi-Sr-Ca-Cu-O Superconductor

The processes of synthesis and decomposition of the high-T c phase of a Pb-doped Bi-Sr-Ca-Cu-O superconductor were studied in terms of the sintering temperature and time. It was found that the high-T c phase incongruently melted and decomposed into the low-T c phase and liquid around 870–880°C. Ca-rich needlelike crystals were newly formed from the liquid (partially melted portion).