A combination of experiments and theoretical calculations was used to develop an atomic-scale model of the grain boundary potential in perovskite oxides. More specifically, pristine 8° and 58° [001] tilt grain boundaries in SrTiO3, which could be regarded as model systems for all cubic perovskite systems, were examined by Z-contrast imaging and electron-energy-loss spectroscopy. Based on results obtained from these systems, distance-valence least-square analysis and multiple-scattering calculations were used to determine the density of grain boundary states for the 8° and 58° grain boundaries, respectively. To compute the grain boundary potentials, the Thomas-Fermi approach of screened charges and the classical Schottky model was used. The validity of both models for various perovskite oxide grain boundary configurations was discussed, and the appropriate grain boundary potentials were compared with previously reported data.

Atomic-Scale Model of the Grain Boundary Potential in Perovskite Oxides. R.F.Klie, M.Beleggia, Y.Zhu, J.P.Buban, N.D.Browning: Physical Review B, 2003, 68[21], 214101 (10pp)