The effect of substitution of Eu on the critical current density and flux pinning properties of (Bi, Pb)-2212 superconductor

摘要

The critical current density and flux pinning properties of Bi(1.6)Pb(0.5)Sr(2-x)EuxCa(1.1)Cu(2.1)Oy ( where x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) prepared by solid state synthesis in bulk polycrystalline form were studied. The samples were characterized by powder x- ray diffraction ( XRD), scanning electron microscopy ( SEM) equipped with energy- dispersive x- ray analysis ( EDS) and superconductivity measurements. The critical temperature ( T-C), critical current density ( J(C)) and field dependence of J(C) of the Eu- substituted samples were found to be highly enhanced for optimum doping levels. The peak position of the normalized pinning force density ( F-p/ F-pmax) is found to shift to higher fields ( 0.88 T) for optimally doped samples in contrast to 0.2 T for the undoped sample. The enhancement of the J(C) - B characteristic and pinning force density FP (F-P = J(C) x B) due to Eu substitution is of great technological significance.