I superconducting systems, withx = 0.4, I 0.3, 0.

high-T, superconducting systems with x = 1 and 2 were prepared by the solid-state reaction method. The system withx = 1 gave the highest T,,.,,, 7 116 K. This paper reports mainly t h e x-ray diffraction analysis of both types of Bi-based systems. In the Bi,,,Pbo.,Sr,Ca,Cu,O, system t h e phases 2223 and 2212 were found, which were tetragonal. Three phases, 2123, 2223 and 2212, were found in the Bi,.,Pb,4Sr,Ca,Cu,0, system. The first two phases were orthorhombic and the last phase was tetragonal. The 2123 phase in the Bi, ,