In-field dependences of the critical current density J$_c$ in GdBa$_2$Cu$_3$O$_{7-d}$ coated conductors produced by Zr irradiation and post-annealing at low temperatures

TL;DR

This study investigates how 6 MeV Zr irradiation and subsequent annealing affect the in-field critical current density of GdBa2Cu3O7-d coated conductors, revealing optimized irradiation improves Jc performance under magnetic fields.

Contribution

It demonstrates that controlled Zr irradiation combined with low-temperature annealing enhances in-field Jc and suppresses disorder effects in GdBa2Cu3O7-d coated conductors.

Findings

Optimal irradiation reduces self-field Jc by ~10%.

In-field Jc nearly doubles at 5 T after annealing.

Correlation between T_c, disorder, and Jc is established.

Abstract

We report the influence of 6 MeV Zr$^{4+}$ irradiation and post-irradiation annealing (200 {\deg}C) in the in-field dependences of the critical current densities J$_c$ of 1.3 $\mu$m thick GdBa$_2$Cu$_3$O$_{7-d}$ coated conductors grown by co-evaporation. Samples were irradiated with 6 MeV Zr$^{4+}$ and fluences between 2.3x10$^{11}$ cm$^{-2}$ and 3x10$^{12}$ cm$^{-2}$. The correlation between the superconducting critical temperature T$_c$ and in-field dependences of critical current densities J$_c$ has been analyzed. In addition, random disorder introduced by irradiation was reduced by thermal annealed at 200 {\deg}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 J$_c$ of $\simeq$ 10 $\%$ and in-field J$_c$ enhancements nearly doubled at about 5 T. A clear correlation between T$_c$, disorder and self-field J$_c$ is observed. Additional random disorder and nanoclusters suppress systematically T$_c$ and increase the flux creep relaxation at intermediate temperatures (reducing the characteristic glassy $\mu$ value).