MICROSTRUCTURE AND PROPERTIES OF YBA2CU3O7 THIN-FILMS GROWN ON VICINAL LAALO3 SUBSTRATES

Thin films of YBa2Cu3O7 have been grown on vicinal LaAlO3 substrates b y pulsed-laser deposition. In most cases, the substrate surface, nomin ally (001), has been rotated similar to 6 degrees about an axis parall el to the <110> direction, Films grown on these surfaces were found to have substantially improved properties compared to those obtained for films deposited on (001)-oriented substrates under equivalent conditi ons at our facility. The surface morphology of the films exhibited an elongated granular structure which differed markedly from the more equ iaxed grain structure found in films grown on (001)-oriented substrate s. Furthermore, this particular elongated morphology and improvement i n properties seems to occur only for films deposited at higher laser e nergies (similar to 30J/cm(2)).