Charge transfer at oxygen/zirconia interface at elevated temperatures: Part 7: Effect of surface processing

The present paper considers the effect of surface processing procedures, such as polishing and subsequent annealing, on oxidation mechanisms and related charge transfer at the oxygen/zirconia interface at elevated temperatures. The studies were performed on yttria-stabilised cubic zirconia (10 mol-%Y2O3) with three surface types: unpolished (as sintered at 1673 K), sintered at 1673 K and then polished, and sintered at 1673 K, polished and reannealed at 1673 K. Work function measurements were used to examine the effect of the applied surface processing procedures on the reactivity of zirconia with oxygen and related charge transfer. This examination involved monitoring changes in work function during oxidation at 1073 and 1173 K. It is shown that surface processing has an effect on the oxidation kinetics and mechanism at both temperatures. Differences in WF data are considered in terms of the local properties of the surface defects formed during processing.