The tracer diffusion coefficient D* and the mobility of protons in proton-conducting oxides of the AIIBIV1-xRIIIxO3-δ family were calculated using the Monte Carlo method as functions of temperature and concentration x of the acceptor impurity RIII. The effect of proton-dopant interactions (proton trapping) and the effect of protonic sites blocking caused by proton-proton and proton - oxygen vacancy interactions, were analyzed. It was shown that the proton diffusivity depended significantly on the dopant content and was considerably reduced already at small x. The D* value weakly depended on the concentration of oxygen vacancies at fixed, not too large values of x. The conductivity dependence on the doping concentration σ(x) could have a maximum due to the proton-defect and proton-proton interactions. The Haven ratio deviates slightly from unity at the expected intensity of interparticle correlations. The calculated values of both the diffusivity activation energy increase (with x), and the location of the σ(x) maxima agree with the experimental data for a number of proton-conducting oxides.

The Influence of Defects on Proton Diffusion in Perovskites AIIBIV1-xRIIIxO3-δ: Monte Carlo Study. V.I.Tsidilkovski, M.Z.Uritsky, A.N.Varaksin, A.Y.Fishman: Defect and Diffusion Forum, 2006, 258-260, 124-9