CRYSTALLIZATION PROCESS IN PB-FREE OR PB-DOPED BI2-XPBXSR2CA2CU3O10-Y GLASS SYSTEM

Bi2-xPbxSr2Ca2Cu3O10-y synthesis (for x = 0.0 and x = 0.3) has been made starting from a glass precursor. After splat quenching, the samples have been annealed at different temperatures for various time spans. X-ray diffraction data and other standard measurements show various growth mechanisms. The 2223 phase results from a dissolution-reprecipitation process rather than from direct recrystallization. A 2201 phase precipitates at high temperature and reacts rapidly with the melt to form the 2223 phase. The kinetics of the lead-substituted sample seems to be controlled by the Ca2PbO4 liquid phase. Alumina contaminated phases have been put into evidence and result from the reaction with the container. Heterogeneous nucleation of the 2223 phase at their surface seems also to exist, as previously reported in other systems.