Thickness dependence of superconducting critical current density in vicinal YBa_(2)Cu_(3)O_(7-δ) thick films

摘要

In YBa_(2)Cu_(3)O_(7-δ) (YBCO) thick films, the superconducting critical current density (J_(c)) decreases with increasing film thickness (t). The mechanisms responsible for this J_(c)-t behavior remain unclear. To probe the correlation between the film microstructure and J_(c)-thickness behavior, we have deposited YBCO thick films up to 3.0 μm in thickness on flat and surface-miscut (100) SrTiO_(3) 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 J_(c)-t behaviors. Surprisingly the small miscut angles of 5°-10° were favorable to obtain higher J_(c) and smaller J_(c) reduction at larger film thickness.