New data are presented on the phase equilibria and crystal chemistry of the binary systems Sr0-Bi203 and SrO-CuO and the ternary system Sr0-Bi203-Cu0. Symmetry data and unit cell dimensions based on single crystal and powder xray diffraction measurements are reported for all the binary Sr0-Bi203 phases, including a new phase identified as Sr6Bi209. The ternary system contains at least four ternary phases which can be formed in air at ~900 C. These are identified as Sr2Bi2Cu06, Sr8Bi4Cu50i9+jt, Sr3Bi2Cu208 and a solid solution (the Raveau phase) which, for equilibrium conditions at ~900 C, corresponds approximately to the formula Sri.8_;,Bi2.2+,Cui,/2O.(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.
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Roth et al. (1990) studied this question.
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