STRUCTURAL INVESTIGATION OF YBCO FILMS AND BICRYSTAL GRAIN-BOUNDARY JUNCTIONS

We present a structural analysis of YBCO superconducting thin films fa bricated in situ by Inverted Cylindrical Magnetron (ICM) sputtering on commercial SrTiO3 single-crystal and bicrystal substrates. A detailed structural characterization of the superconductor films was performed by using single-crystal X-ray diffractometry confirming that YBCO fil ms have a strong c-axis orientation of the grains with a small mosaic spread. In the films grown on bicrystal substrates we observed a stron g correlation with the lattice structure of the substrate. In addition , a surface analysis of the region across the grain boundary edge has been performed by using scanning electron microscopy.