Growth and Structure of Buffer Layers for High Temperature Superconducting Films

We have studied thin CeO$\text{}_{2}$ buffer layers prepared by aerosol MOCVD on (11̅02) Al$\text{}_{2}$O$\text{}_{3}$ substrate at high deposition temperature, T$\text{}_{d}$= 900°C. A texture analysis by X-ray diffraction showed a high degree of epitaxial character of CeO$\text{}_{2}$ films. A study of the microstructure by transmission electron microscopy revealed that the CeO$\text{}_{2}$ films are in a relaxed state being composed of slightly misoriented blocks surrounded by dislocations. The films are smooth, giving mean square root values of the surface roughness measured by atomic force microscopy up to 1 nm.