Proton diffusion in perovskites: comparison between BaCeO3, BaZrO3, SrTiO3, and CaTiO3 using quantum molecular dynamics

Quantum molecular dynamics simulations have been carried out to calculate t he diffusion coefficients and the activation energies of protonic defects i n BaCeO3, BaZrO3, SrTiO3 and CaTiO3. The calculated activation energies are in agreement with experimental data within statistical uncertainty. The ac tivation energy for proton transfer is found to be significantly affected b y the repulsive interaction of the proton with the B-cation (B=Ce, Zr, Ti). A physical interpretation for the measured infra-red spectra can also be o btained From the numerical results. (C) 2000 Elsevier Science B.V. All righ ts reserved.