A classical force-field model, with partial ionic charges, was used to study the behaviour of oxygen vacancies in the perovskite oxide. The dynamic behaviour of these point defects was investigated as a function of temperature and defect concentration by means of molecular dynamics simulations. The interaction between oxygen vacancies and an extended defect, here a Σ3(111) grain boundary, was also examined by means of molecular dynamics simulations. Analysis of the vacancy distribution revealed a considerable accumulation of vacancies in the envelope of the grain boundary. Possible clustering of oxygen vacancies in bulk SrTiO3 was studied by means of static lattice calculations within the Mott-Littleton approach. All binary vacancy-vacancy configurations were found to be energetically unfavourable.

Molecular Dynamics Simulations of Oxygen Vacancy Diffusion in SrTiO3. Schie, M., Marchewka, A., Müller, T., De Souza, R.A., Waser, R.: Journal of Physics Condensed Matter, 2012, 24[48], 485002