Microstructure and phase development of as-quenched and annealed samples of the glass of composition Pb0.32Bi1.68Sr1.75Ca2Cu3Ox have been studied. Evidence for liquid-liquid phase separation during quenching was found The microstructure of this glass during the early stage of crystallization is similar to that found for Bi2Sr2CaCu2Ox (2212) glass. The first phase that crystallizes on annealing at low temperatures appears to be Cu2O. In further heat treatments the sequential crystallization of the R-phase of (PbyBi2-y)Sr2CuOx ('2201') composition and the PbyBi2-ySr2CaCu2Ox ('2212') phase was found, in agreement with other studies. Phase separation determines the initial crystal phase and the development of the superconducting phases. Phase separation observed in this glass points to the possibility that immiscibility may be a common feature of a wide range of Bi(or PbBi)SrCaCuO compositions.
ASJC Scopus subject areas
- Ceramics and Composites
- Electronic, Optical and Magnetic Materials