The Monte Carlo technique was used to calculate the dependences of the tracer diffusion coefficient D* and conductivity σ of protons on the temperature and content x of the acceptor dopant in oxides with a distorted fluorite (bixbyite) structure. The analysis was carried out for calcium-doped Y2O3 as an example. The effect of dopant-generated traps (different energy states for protons) and the effect of site blocking due to interactions of protons between themselves and with oxygen vacancies were considered. It was shown that the mobility of protons decreased significantly as a result of doping already at about 1mol%. The behavior of conductivity depended noticeably upon the distribution of dopant ions over non-equivalent cation sites in the lattice. The predominant dopant distribution over the sites of the same type accounted for the appearance of a maximum in the dependence of σ(x) when correlations were taken into account.

Proton Transport in Doped Yttrium Oxide. Monte-Carlo Simulation. M.Z.Uritsky, V.I.Tsidilkovski: Russian Journal of Electrochemistry, 2012, 48[9], 917-21