Cu-free synthesis of screen-printed YBCO superconductor on Cu plates

Abstract

YBa2Cu3O7-delta (YBCO) superconducting films were fabricated on Cu plates for simplicity of the whole process using Cu-free Y2O3 and BaCO3 mixed powders (attrition-milled) by screen-printing method. The experiment conditions were designed from the pre-experiment of Cu oxidation and the mixing ratio of Y2O3 and BaCO3 mixed powders and the ternary phase diagram of Y2O3, BaO and CuO for YBCO. The properties of screen-printed films were characterized by using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersion spectroscopy (EDS) analysis. The possibility that the formed YBCO films show the superconducting properties was also evaluated from the superconductivity transition temperature (T-c) measurement. The screen-printed films were composed of three layers: Cu oxide, YBCO and Cu oxide. As the reaction temperature increased, the upper Cu oxide layer was reduced and Tc was improved. Cu-free synthesis of screen-printed YBCO films were possible on Cu plates. (C) 2004 Elsevier B.V. All rights reserved.