Effect of (CuPb)x Substitution on Tc of Bi2-x(CuPb)x Sr2Ca2Cu3O10+δ Superconductors


High temperature superconductors with a nominal compositionBi2-x (CuPb) xSr2Ca2Cu3O10+δ for (0≤x≤0.5) were prepared by solid state reaction method.The effect of (CuPb) x substitution on Tc of Bi2-x(CuPb)xSr2Ca2Cu3O10+δ compoundhas been investigated by X-ray diffraction , resistance measurements and oxygencontent to obtain the optimum conditions for the formation and stabilization of thehigh TC phase (2223- phase).The results showed that the optimum sinteringtemperature for the composition Bi2-x(CuPb)xSr2Ca2Cu3O10+δ is Ts=1133K forts=140h.The x-ray diffraction (XRD) analysis showed that all the samples have almost twophases: high-Tc phase (2223- phase) and low-TC phase (2212- phase). It was foundthat all the samples having an orthorhombic structure with lattice parameter value (c)increased with increasing of the critical temperature Tc.Substitution of (CuPb)x to 0.1, 0.3, 0.4 increases the transition temperature toTC=107K, 125K, 95K, respectively.