Magnetic and Electrical Properties of Superconducting Ceramic YBa2Cu3O7−δ Co-doped with Ca and Zn

Superconducting Y1−xCaxBa2(Cu0.98Zn0.02)3O7−δ ceramics with 0≤x≤0.5 have been prepared by the solid state reaction method. Structural, magnetic and electrical properties of the components have been studied. To characterize the samples, X-rays diffraction (XRD), scanning electron microscopy (SEM) and magnetic measurements techniques are used. Obtained results show that increasing the Ca content leads to a significant decrease of the Y123 phase. While, the parasite phase BaCuO2 increases. For x>0.3, the coexistence of metallic and semiconducting character of samples is observed. DC susceptibility measurements reveal a reduction of the Meissner fraction with Ca doping, suggesting the existence of the flux pining effect.