BaCe0.95Nd0.05O3-
and SrCe0.95Y0.05O3- are determined using an isotope exchange method in the temperature range 630–820°C at oxygen pressures of 2.7–13.3 gPa and diffusion coefficients for oxygen are calculated.
Effective energies of activation of oxygen exchange and diffusion coefficients for oxygen are calculated. Depen-
dence of exchange characteristics and the diffusion coefficients on the oxygen pressure in the gas phase is inves-
tigated. The oxygen exchange on the surface of studied oxides is shown to proceed only with the participation of
oxygen of the oxides, which causes high rates of interphase exchange of oxygen of studied cerates of barium and
strontium. It is shown that the obtained data satisfactorily agree with those found in the relevant literature.