The effect of Sb substitution on properties of Bi1.6Pb0.4Sr2−xSbxCa2Cu3Oy superconductors

The effect of the partial substitution of Sr by Sb in the Bi-based superconducting materials has been investigated by X-ray diffraction (XRD), dc electrical resistivity, magnetoresistivity and critical temperature. Maximum value of the volume fraction of high-Tc phase was calculated to be 69.83 for the sample having Sb content x=0.06; the same sample has also shown the highest Tc(0) value of 107.8 K amongst the samples. We estimated the transition temperature of the samples from the resistivity versus temperature measurements in dc magnetic fields up to 0.5 T. All samples exhibit metal-like behavior and appear to have a multiphase character. The lattice parameters and cell volume were found to be affected by substitution of Sb at the Sr-site.