Microscopic mechanism of proton conduction in perovskite oxides from ab initio molecular dynamics simulations

The microscopic mechanism of proton diffusion in the protonic conductor Sc- doped SrTiO3 is studied by ab initio molecular dynamics (MD) simulations ba sed on the generalized gradient-corrected density functional theory (DFT). It is shown that the frequencies of the O-H stretching vibration are in goo d agreement with the infrared transmission measurements, and that the disto rtion of the oxygen sublattice around the oxygen vacancy enables the pathwa y of the proton diffusion between the second nearest neighbor O ions, which are never seen in the crystal without the oxygen vacancies. (C) 2001 Elsev ier Science B.V. All rights reserved.