Phase Equilibria and Crystal Chemistry in Portions of the System SrO-CaO-Bi(2)O(3)-CuO, Part II—The System SrO-Bi(2)O(3)-CuO

New data are presented on the phase equilibria and crystal chemistry of the binary systems Sr0-Bi(2)0(3) and SrO-CuO and the ternary system SrO-Bi(2)O(3)-CuO. Symmetry data and unit cell dimensions based on single crystal and powder x-ray diffraction measurements are reported for all the binary SrO-Bi(2)O(3) phases, including a new phase identified as Sr(6)Bi(2)O(9). The ternary system contains at least four ternary phases which can be formed in air at ~900 °C. These are identified as Sr(2)Bi(2)CuO(6), Sr(8)Bi(4)Cu(5)O(19+)(x), Sr(3)Bi(2)Cu(2)O(8) and a solid solution (the Raveau phase) which, for equilibrium conditions at ~900 °C, corresponds approximately to the formula Sr(1.8−)(x)Bi(2.2+)(x)Cu(1±)(x)(/2)O(z).(0.0⩽x⩽~0.15). Superconductivity in this phase apparently occurs only in compositions that correspond to negative values of x. Compositions that lie outside the equilibrium Raveau-phase field often form nearly homogeneous Raveau-phase products. Typically this occurs after relatively brief heat treatments, or in crystallization of a quenched melt.