Temperature-programmed C18O2 SSITKA for powders of fast oxide-ion conductors: Estimation of oxygen self-diffusion coefficients

For powders of oxide-ion conductors based on Al/Fe- doped lanthanum silicates as well as Sc+Ce-doped zirconia, the temperature -programmed exchange with C18O2 in the SSITKA mode was applied for estimation of the oxygen self-diffusion coefficients Do. Comparison with results obtained for dense ceramics of these electrolytes using SIMS isotope profiling and conductivity measurements demonstrated a reasonable agreement for powders sintered at high temperatures, thus providing required verification of C18O2 SSITKA approach. For powders calcined at moderate temperatures much lower values of DO were obtained thus suggesting a strong negative effect of inhomogeneity of dopants spatial distribution on the oxygen mobility.