State-of-the-art flux pinning in YBa₂Cu₃O_{7 − δ}by the creation of highly linear, segmented nanorods of Ba₂(Y /Gd)(Nb/Ta)O₆together with nanoparticles of (Y /Gd)₂O₃and (Y /Gd)Ba₂Cu₄O₈

Abstract

Self-assembled, segmented nanorods of c-axis-aligned Ba2(Y /Gd)(Nb/Ta)O6 as well as randomly distributed nanoparticles of (Y /Gd)2O3 and (Y /Gd)Ba2Cu4O8 were grown into YBa2Cu3O7 − δ (YBCO) thin films by pulsed-laser deposition. The complex pinning landscape proves to be extremely effective, particularly at higher fields where the segmented vortices yield a plateau in critical current density (Jc) with field angle around 60°. In 0.3 µm thick films, the Jc values are higher than 1 MA cm − 2 at 2.5 T ( axis). Owing to the combined interactions of the vortices with the different pinning centres, interesting new features are observed at high fields in the angular dependence of Jc.