CONTROL OF EPITAXIAL-GROWTH ORIENTATION IN YBA2CU3O7-DELTA FILMS ON VICINAL (110)SRTIO3 SUBSTRATES

Films of YBa2Cu3O7-delta (YBCO) were grown on (001), exact and vicinal (110), and (111) SrTiO3 single crystal substrates by pulsed laser dep osition, and evaluated by x-ray diffraction and scanning force microsc opy (AFM). It was observed that the YBCO was always epitaxially aligne d to the substrate with the [001] (c-axis) parallel to a substrate cub e axis direction. For the exact (001), (110), and (111) surfaces, ther e were one, two, and three orientations, respectively. For the vicinal (110) surfaces, however, there was usually only one discernible c-axi s orientation, corresponding to a single {013} film surface orientatio n. The reduction of the (110) surface twofold symmetry by use of a vic inal substrate thus allowed controlled growth of a YBCO single crystal with an inclined c-axis orientation.