Growth mechanism of YBa2Cu3O7–δthin films and precipitates on planar and vicinal SrTiO3substrates

Abstract

Effects of the vicinal angle, film thickness, and temperature on the growth modes, microstructures, and electrical properties of YBa2Cu3O7–δon SrTiO3were studied. Island growth transition between the initial nucleation and the later coalescence stages was observed with film thickness on a planar SrTiO3, while no islands were observed at the later stage due to the step-flow mode. As the growth temperature increased,a-axis precipitates were transformed toc-axis precipitates (islands), while no islands formed on vicinal SrTiO3. The supercurrent critical temperature was strongly related to the substrate vicinal angle due to the step-flow mode.