Comparative studies for the physical properties of superconducting (BaSnO3)x(Bi,Pb)-2223 samples determined from excess conductivity and thermoelectric power analysis

Abstract

To study the effects of BaSnO3 nanoparticles addition to BSCCO superconducting system, five polycrystalline samples with general formula (BaSnO3)x(Bi1.6Pb0.4)Sr2Ca2Cu3O10−δ (BaSnO3)x(Bi,Pb)-2223, with were prepared by the conventional solid-state reaction technique. X-ray diffraction (XRD, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX) were used for structural characterization of the samples. The room temperature x-ray diffraction patterns as well as the SEM/EDX micrographs of the samples indicate the formation of the major Bi-(2223) phase. To get into the conduction mechanisms of (BaSnO3)x(Bi,Pb)-2223, it was important to study the electrical resistivity with superconducting induced fluctuations as well as thermoelectric power. By applying several theoretical models to the analysis of experimental results, a number of physical parameters was extracted such as superconducting-transition temperature Tc, coherence length along c-axis ξc(0), effective layer thickness d, Fermi velocity vF as well as Fermi energy EF were calculated as a function of BaSnO3-content.