Tuning flux-pinning in epitaxial NdBa₂Cu₃O _7-δ films via engineered, hybrid nanoscale defect structures

Epitaxial NdBa₂Cu₃O_7-δ films with a hybrid nanoscale defect structure comprised of BaZrO3 nanodot arrays aligned along the c-axis in one half of the film thickness and aligned perpendicular to the c-axis in the other half thickness of the film were fabricated. Transmission electron microscopy images confirm the orientation of the nanoscale defect structures. The angular dependence of critical current density, J_c, at 77 K, 1 T, shows significantly reduced angular variation of J_c. This study nicely demonstrates how pinning characteristics can be tuned by tuning the nanoscale defect structures within the films.