Critical-current variation with Pr content in Y1−xPrxBa2Cu3O7 epitaxial films

Abstract

c-axis-oriented epitaxial Y1-xPrxBa2Cu3O7 (x=0, 0.05, 0.1, 0.2, 0.3, and 0.35) thin films have been grown with the pulsed-laser-deposition method. Superconducting transition temperatures of the films are within +/-2 K of the corresponding polycrystalline bulk samples. The critical current density Jc of Pr-doped films for x=0.1-0.3 is about two orders of magnitude lower than of the pure 1:2:3 films. This exponential fall in Jc with doping (x) can be understood semiquantitatively in terms of depairing due to a random-impurity (Pr-ion) potential causing localized suppression of the superconducting order parameter around the impurity to about the in-plane coherence length.