Tuning Flux-pinning in Epitaxial NdBa2Cu3O7-δFilms via Engineered, Hybrid Nanoscale Defect Structures

Epitaxial NdBa 2 Cu 3 O 7-δ films with a hybrid nanoscale defect structure comprised of BaZrO 3 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.