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

Abstract

The critical current density and flux pinning properties ofBi1.6Pb0.5Sr2−xEuxCa1.1Cu2.1Oy (where x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) prepared by solid state synthesis in bulk polycrystallineform were studied. The samples were characterized by powder x-ray diffraction(XRD), scanning electron microscopy (SEM) equipped with energy-dispersive x-rayanalysis (EDS) and superconductivity measurements. The critical temperature(TC), critical currentdensity (JC) and fielddependence of JC of the Eu-substituted samples were found to be highly enhanced for optimumdoping levels. The peak position of the normalized pinning force density(Fp/Fpmax) is found to shift to higher fields (0.88 T) for optimally doped samplesin contrast to 0.2 T for the undoped sample. The enhancement of theJC–B characteristic andpinning force density FP (FP = JC × B) due to Eu substitution is of great technological significance.