GROWTH AND STRUCTURE OF BUFFER LAYERS FOR HIGH-TEMPERATURE SUPERCONDUCTING FILMS

We have studied thin CeO2 buffer layers prepared by aerosol MOCVD on ( <1(1)over bar 02>) Al2O3 substrate at high deposition temperature, Td = 900 degrees C. A texture analysis by X-ray diffraction showed a high degree of epitaxial character of CeO2 films. A study of the microstru cture by transmission electron microscopy revealed that the CeO2 films are in a relaxed state being composed of slightly misoriented blocks surrounded by dislocations. The films are smooth, giving mean square r oot values of the surface roughness measured by atomic force microscop y up to 1 nm.