Phase equilibria and crystal chemistry in portions of the system SrO-CaO-Bi2O3-CuO, Part II - The system SrO-Bi2O3-CuO

Abstract

New data are presented on the phase equilibria and crystal chemistry of the binary systems Sr0-Bi203 and SrO-CuO and the ternary system SrO-Bi2O3-CuO. Symmetry data and unit cell dimensions based on single crystal and powder x-ray diffraction measurements are reported for all the binary SrO-Bi2O3 phases, including a new phase identified as Sr6Bi2O9. The ternary system contains at least four ternary phases which can be formed in air at ~900 °C. These are identified as Sr2Bi2CuO6, Sr8Bi4Cu5O19+x, Sr3Bi2Cu2O8 and a solid solution (the Raveau phase) which, for equilibrium conditions at ~900 °C, corresponds approximately to the formula Sr1.8−xBi2.2+xCu1±x/2Oz.(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.

Molecular beam epitaxy: a path to novel high Tc superconductors?

“…The growth conditions, structural features, and asgrown Tc (p0) of the samples to be discussed are given in Table 1 . The pattern of spots is consistent with the oriented presence of the Sr6Bi2O9 11,12 Since only a 2212like phase was observed by x-ray diffraction after growth, and SEM images of the surface (shown in Fig. A sequence of RHEED patterns observed during the growth of a 2212-like film is shown in Fig.…”

Structural behavior of Sr2Bi2O5 at high pressures

“…The phase diagram of the Bi-Sr-O ternary system has been investigated over its entire compositional range [1][2][3]. Besides the solid solutions of SrO in Bi 2 O 3 , there are at least five stable ternary phases in the system.…”

Stability, Oxygen Nonstoichiometry, and Transformations of the Bi2Sr2CoO6+δCeramic

“…Chemical reaction (nucleation and growth of nuclei) 2Bi Sr CoO where ( m/m ) R is the weight gain observed at time t and ( m/m ) is the theoretical weight gain corresponding to complete proceeding of reaction [8].…”