Thickness dependence of superconducting critical current densityin vicinal YBa2Cu3O7−δ thick films

Abstract

In YBa2Cu3O7−δ (YBCO) thick films, the superconducting critical current density (Jc) decreases with increasing film thickness (t). The mechanisms responsible for this Jc–t behavior remain unclear. To probe the correlation between the film microstructure and Jc-thickness behavior, we have deposited YBCO thick films up to 3.0μm in thickness on flat and surface-miscut (100) SrTiO3 substrates with 5°, 10°, and 15° vicinal angles. The microstructures of the YBCO films were found to evolve differently on flat and miscut substrates, resulting in different Jc–t behaviors. Surprisingly the small miscut angles of 5°–10° were favorable to obtain higher Jc and smaller Jc reduction at larger film thickness.