Raman spectra, microstructure and superconducting properties of Sb(III)–YBCO composite superconductor

Abstract

The pure YBCO (YBa 2Cu 3O 7) and its variant antimony containing composites with general formula; Y 1+ x Sb x Ba 2Cu 3O z , where x = 0.1, 0.2, 0.4 and 0.6 mol%, respectively, were prepared by the solid-state reaction route. X-ray measurements indicated that Sb 3+ ions have a negligible effect on the main crystalline structure and substitutes Y-sites successfully in lattice structure of 123-YBCO at low concentrations of doping ( x = 0.1 → 0.2). From SE-microscopy mapping and EDX elemental analysis, Sb 3+ was detected qualitatively with good approximation to the actual molar ratio but not observed at 123-YBCO grain boundaries which confirm that antimony (III) has diffused regularly into material bulk of superconducting 123-YBCO-phase at low concentrations. Additions of Sb(III) affected sharply on the main vibrating modes of YBCO regime particularly, on the apical oxygen (O 4) vibrational mode A 1g. Magnetic susceptibility measurements proved that antimony oxide additions have slight effect on the transport properties of YBCO-composites regime.