SUPERCONDUCTIVITY IN Pb-DOPED Bi-Ca-Sr-Cu-O SYSTEM

A new superconducting transition near 100 K was observed in the Pb-doped Bi-Ca-Sr-Cu-O samples. Compared with the 107 K and 65 K phases, the volume fraction of this superconducting phase is very small, but forms an effective connection between the grains of other two phases. It is suggested that the new phase plays an important role for Tc above 100 K in the Bi2−xPbxCa2Sr2Cu3Oy system.