Enhanced flux pinning and critical currents in YBa₂Cu ₃O_7-δ films by nanoparticle surface decoration: Extension to coated conductor templates

Interfacial engineering via nanoparticle substrate surface decoration has been extended to coated conductor templates. Preformed BaTiO₃ and BaZrO₃ nanoparticles were applied to substrate surfaces, prior to YBa₂Cu₃O_7-δ (YBCO) deposition, by using a scalable and inexpensive technique of solution-based suspension. Compared to untreated reference samples, nanodecoration yields improved in-field critical current density (J_c) as well as strong correlated pinning along the c -axis direction of the YBCO film. Accordingly, a much reduced falloff of J _c with magnetic field strength was observed in all of the modified samples. In addition, scaling behavior of the normalized volume pinning force density (F_p) with respect to temperature provided insight as to the differences in flux pinning mechanisms dependent on the decoration technique. Finally, with these results our earlier proof-of-concept demonstrations on nanoparticle modified single crystal substrates were replicated on technological substrates, pointing to the versatility of this simple technique for realization of enhanced high temperature superconductor performance.