The effect of Cd doping on Bi-based superconductor

Abstract

In this study, the Cd substitution effects on Bi-based superconductors have been investigated. Samples of Bi1.6PbxCdzSr2Ca2Cu3Oy, where (z, x) = (0.01, 0.39), (0.02, 0.38), (0.03, 0.37), (0.04, 0.36), (0.05, 0.35), (0.06,0.34), (0.07,0.33), (0.08, 0.32), (0.09, 0.31) and (0.1, 0.3) were fabricated by the solid state reaction method, using the powders of Bi2O3, PbO, CUO,CaCO3, SrCO3 and CdO as starting materials. The structural analysis was carried out by XRD, SEM and EDX measurements. The XRD results show that the unwanted phases in the samples were reduced by increasing the amount of Cd and annealing time. The maximum fraction of Bi (2223) phase obtained in the sample with z=0.04 and annealing time of 270 h. The critical temperature (Tc) and critical current density (Jc) were measured at 77 K. The maximum critical current density and the critical temperature were obtained in a sample with z = 0.04 for annealing time of 270 h. In order to study the effect of Cd on the room temperature resistivity of the samples, the V-I curves of the samples were measured at room temperature. The resistance of Cd-doped samples at room temperature increase when the amount of Cd is increased. It decreases by increasing the annealing time. © 2008 Asian Network for Scientific Information.