Synthesis And Characterization Of Glass-Ceramic Superconductors In (Pb, B)-Doped Bi-Sr-Ca-Cu-O System

Glass-ceramic superconductors in the Bi-Sr-Ca-Cu-O system were prepared by melt-quenching method in the presence of some additives (Pb, B). The studied glasses were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (DTA/TGA) and differential scanning calorimetry (DSC). On the crystallized ceramics obtained by the annealing the glasses, transport resistance and XRD measurements were also done. The glass transition temperatures (T-g) was found to range in the 380-430 degrees C domain, followed by a set of exothermal effects that could be assigned to the crystallization of the superconducting phases. The nucleation and growth of the crystals is influenced by both the nature of the oxides used as additives and by their ratio. So, the samples doped with low amount of B (x=0.1 and 0.2) present obvious transitions at about 110 K, highlighting the presence of the 2223 phase in highest amount and well interconnected.