The Effect of Sn Substitution of Pb on Microstructure and Superconducting Properties of Bi–Pb–Sr–Ca–Cu–O Superconductor

Abstract

The effect of substitution of Pb by Sn in Bi1.6Pb0.4−xSnxSr2Ca2Cu3Oδ samples at x = 0.0, 0.1, 0.2, and 0.3 on the critical transition temperature and structural properties was investigated in this work. All the samples were prepared by the solid-state reaction method. The prepared samples were characterized by X-ray diffraction (XRD), resistance–temperature curve (R–T), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The Sn 4+ substitution of Pb 2+ caused significant changes in the properties of the samples. The formation of the (Bi, Pb)-2212 phase was stabilized and the Tc (onset) was improved at the x = 0.2 level of Sn 4+ substitution. The SEM micrographs have shown that the structure of the sample with x = 0.2 became more dense. However, samples with x = 0.1 and 0.3 have not shown zero resistance by EDS analysis because of oxygen deficiency.