Growth of high Tc-superconducting Y-Ba-Cu-O thin films by a chemical spray pyrolysis method

Abstract

A chemical spray pyrolysis method has been applied to grow high Tc Y-Ba-Cu-O thin films on SiO2, (001)SrTiO3 and (001)MgO substrates. The best results were obtained for films deposited on (001)SrTiO3 and (001)MgO substrates with Tc onset at 95 and 82 and Tc zero at 82 and 76 K, respectively. For films deposited on MgO, X-ray diffraction pattern revealed that the films are highly preferentially oriented with respect to MgO substrates with the C-axis parallel to the normal of the substrate surface. Both planview and cross-sectional transmission electron microscopy have been applied to characterize the 6pitaxia1 films. The orientation relationships between the epitaxial films and the substrate were analyzed to be [001]YBCO//[001]MgO and (110)YBCO//(200)MgO. Twins, which may be preceived as domains that are rotated 900 along the C-axis of the thin films with respect to the substrate, were found to be copiously present. © 1988 Elsevier Science Publishers B.V.