The atomic structure, composition and bonding at a nominally undoped 58° [001] tilt grain boundary were studied in order to understand the effect which the grain boundary plane had upon the bulk properties. Room temperature and in situ heating experiments showed that there was a segregation of O vacancies to the grain boundary. This increased at high temperatures, and was independent of the cation arrangement. These measurements provided direct support for experimental and theoretical predictions that non-stoichiometry (especially that of O vacancies) was responsible for the widely observed grain boundary properties.

Atomic-Scale Characterization of Oxygen Vacancy Segregation at SrTiO3 Grain Boundaries. R.F.Klie, N.D.Browning: Applied Physics Letters, 2000, 77[23], 3737-9