Direct-current conductivity measurements were used to monitor isothermal equilibration in undoped single crystals, at temperatures ranging from 950 to 1206K, during oxidation and reduction experiments. It was deduced that the chemical diffusivity could be described by:

D (cm2/s) = 4.32 x 10-2 exp[-79.58(kJ/mol)/RT]

The diffusivity exhibited a complex dependence upon the O partial pressure.

Diffusion in BaTiO3 under Chemical Potential Gradient. J.Nowotny, M.Rekas, C.C.Sorrell, H.I.Yoo: Journal of the Australasian Ceramic Society, 1998, 34[1], 80-5