Study and Analysis of Calcium Substitution in Y0.8Pr0.2Ba2Cu3O7- Δ

Abstract

YBa2Cu3O7−δ cuprate is a suitable system for the study of impurity effect on superconducting properties because carrier concentration can be widely changed without introducing significant disorder. Thus, the effect of replacing Cu by Co atoms, and Y by Ca atoms is reported to provide useful information about the mechanism of high-Tc superconductivity. In this paper, we have investigated the effect of Ca and Co simultaneous substitution on the structural and physical properties for a series of (Y1−xCax)Ba2(Cu0.98Co0.02)3O7−δ (0 ≤ x ≤ 0.35) ceramic. Doped Y123 samples are prepared by conventional solid-state reaction method and characterized by X-ray diffraction (XRD), SEM, and resistivity measurements. We found that the obtained crystalline structure is mainly orthorhombic. No parasite phase is observed. The orthorhombicity increases with Ca content. The analysis of the superconducting behavior of the samples showed that co-substitution of Ca does not counteract the adverse influence of Co within the single-phase range Introduction