PHASE-STRUCTURE AND THERMAL EVOLUTION IN COATINGS AND POWDERS OBTAINED BY THE SOL-GEL PROCESS .1. ZRO2-11.3 MOL-PERCENT Y2O3

Yttria-stabilized cubic zirconia powders and coatings produced by the sol-gel method have been investigated by Perturbed Angular Correlation Spectroscopy (PAC). Results indicate that the metastable cubic phase is retained during heating and cooling cycles. The hyperfine interacti on that describes this cubic phase, once crystallized, exhibits two co mponents in a constant ratio of 4:1. The components represent differen t vacancy configurations. For the fast movement of oxygen vacancies st arting at 750 degrees C, which is reflected by the damping of the hype rfine pattern, an activation energy of 0.96 eV was determined.