The doped samples exhibit higher surface concentrations as well
as higher surface exchange coefficients as compared to the undoped
sample. This indicates that doping has a direct influence to the oxygen
incorporation reaction most probably due to allocation of electrons by
transition metals to the oxygen dissociation step. Additionally, the increased
favourability of the interstitial sites (ability of the dopants to potentially
increase the coordination sphere above four) could contribute
to a higher incorporation rate as well.