High-field critical current density enhancement in GdBCO coated conductors by cooperative defects

Irradiation can precisely control defects in, and improve the superconducting properties of, REBa₂Cu₃O_7−δ (REBCO, RE: rare earth) coated conductors (CCs). Here we report an effective approach for enhancing the in-field performance of GdBCO CCs. The critical current density (J _c) of GdBCO films was significantly improved through cooperative defects created by co-irradiation with O ions and protons, especially at low temperatures and high magnetic fields. Surprisingly, the in-field J _c of commercial CCs can be nearly doubled. The cooperative irradiation-induced defects are uniformly distributed throughout the GdBCO layer, which promotes the overall performance of the CC. Moreover, the dimensions of these irradiation-induced defects closely match the coherence length of REBCO. This simple and efficient method is a practical post-production solution to improve the in-field performance of commercial REBCO CCs.