Temperature-programmed C super(18)O sub(2) 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 C super(18)O sub(2) in the SSITKA mode was applied for estimation of the oxygen self-diffusion coefficients D sub(o). 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 C super(18)O sub(2) SSITKA approach. For powders calcined at moderate temperatures much lower values of D sub(o) were obtained thus suggesting a strong negative effect of inhomogeneity of dopants spatial distribution on the oxygen mobility.