title: Direct observation of charge transfer at a MgO(111) surface.
abstract: Transmission electron diffraction (TED) combined with direct methods have been used to study the sqrt[3]xsqrt[3]R30 degrees reconstruction on the polar (111) surface of MgO and refine the valence charge distribution. The surface is nonstoichiometric and is terminated by a single magnesium atom. A charge-compensating electron hole is localized in the next oxygen layer and there is a nominal charge transfer from the oxygen atoms to the top magnesium atom. The partial charges that we obtain for the surface atoms are in reasonable agreement with empirical bond-valence estimations.
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, USA.
authors.forename: A
authors.initials: A
authors.lastname: Subramanian
authors.forename: L D
authors.initials: LD
authors.lastname: Marks
authors.forename: O
authors.initials: O
authors.lastname: Warschkow
authors.forename: D E
authors.initials: DE
authors.lastname: Ellis