SEGREGATION, INTERFACE REACTIONS AND SURFACE-TOPOGRAPHY OF YBA2CU3O7-DELTA THIN-FILMS, INVESTIGATED BY AUGER DEPTH PROFILING, MICROPROBE ANALYSIS, STM AND SEM

Thin films of the high Tc superconductor YBaCuO, prepared by co-evaporation on substrates of ZrO2and SrTiO3, have been examined with Auger electron depth profile analysis, microprobe analysis, scanning electron microscopy and scanning tunneling microscopy. The Auger depth profiles unveil pronounced diffusion of Ba into the substrate for films prepared on ZrO2. Introduction of a Pt buffer layer at the interface promotes strong segregation of the metallic elements in the film. The STM images provide quantitative data on the surface topography and are shown to correlate excellently with SEM micrographs.