Revisiting the Y1-xPrxBa2Cu3O7-δ system- CuO2 plane disorder induced flux pinning

Abstract

Sample of Y1-xPrxBa2Cu3O7 with x = 0.0 to 0.80 are synthesized by solid- state reaction route. All the samples crystallized in orthorhombic structure with space group pmmm. Slight decrease in orthorhombicity is seen with an increase in Pr content. Superconductivity is destroyed above 50% Pr content. Non-superconducting samples are highly semi conducting. Detailed high field magnetization (M-H) measurements showed that the lower critical field (Hc1) improves slightly with Pr content of up to 4% and the same later decreases for higher Pr contents. The critical current density calculated by invoking Bean's critical state model improves dramatically until x=0.04 and decrease later for higher Pr contents in comparison to the pristine sample. These results are explained on the basis of Pr4f and O2p hybridization induced disorder in superconducting CuO2 planes. For low Pr content the mild disorder in superconducting condensate (CuO2 plane) induces intrinsic pinning and hence resulting in an increased Jc(H) and Hc1.