Control of epitaxial growth orientation in YBa2Cu3O7−δ films on vicinal (110) SrTiO3 substrates

Films of Yba2Cu3O7−δ (YBCO) were grown on (001), exact and vicinal (110), and (111) SrTiO3 single crystal substrates by pulsed laser deposition, and evaluated by x-ray diffraction and scanning force microscopy (AFM). It was observed that the YBCO was always epitaxially aligned to the substrate with the [001] (c-axis) parallel to a substrate cube axis direction. For the exact (001), (110), and (111) surfaces, there were one, two, and three orientations, respectively. For the vicinal (110) surfaces, however, there was usually only one discernible c-axis orientation, corresponding to a single {013} film surface orientation. The reduction of the (110) surface twofold symmetry by use of a vicinal substrate thus allowed controlled growth of a YBCO single crystal with an inclined c-axis orientation.