In-field dependences of the critical current density Jc in GdBa2Cu3O7-d coated conductors produced by Zr irradiation and post-annealing at low temperatures

Abstract

We report the influence of 6 MeV Zr4+irradiation and post-irradiation annealing (200 °C) in the in-field dependences of the critical current densities Jc of 1.3 thick GdBa2Cu3O7-d coated conductors grown by co-evaporation. Samples were irradiated with 6 MeV Zr4+ and fluences between 2.3 × 1011 cm−2 and 3 × 1012 cm−2. The correlation between the superconducting critical temperature Tc and in-field dependences of Jc has been analyzed. In addition, random disorder introduced by irradiation was reduced by thermal annealed at 200 °C. The analysis of our experimental findings indicates that the optimal irradiation (reducing random disorder by annealing) results in the suppression of the self-field Jc of ≈10% and in-field Jc enhancements nearly doubled at about 5 T. A clear correlation between Tc, disorder and self-field Jc is observed. Additional random disorder and nanoclusters suppress systematically Tc and increase the flux creep relaxation at intermediate temperatures (reducing the characteristic glassy μ value).