Effect of Ca Substitution at Y-Site of YB2C3O7 Superconductor Prepared via Co-Precipitation Method

Abstract

The effect of Ca substitution in Y1-xCaxBa2Cu3O7 superconductor prepared via co-precipitation method has been investigated. The concentration of Ca substitution was varied from x = 0.05 to x = 0.20. The samples were characterized using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (SEM), resistivity measurement and current density measurement (without magnetic field). The critical temperature of the samples decreased as the concentration of Ca be increased whereby the highest value of critical temperature (Tc zero) was 83 K at x = 0.05. The crystallographic structure of pure sample was evidenced to be orthorhombic form where a ≠ b ≠ c.. At x = 0.10, the microstructure showed an improvement in grain alignment compared to other Ca concentration. The critical current density (Jc) increased with Ca concentration. The value of Jc for x = 0.05 at 50 K and 60 K was 1.51 A/cm2 and 1.00 A/cm2, respectively.