We have performed density functional theory-generalized gradient approximation periodic calculations to study the formation of an oxygen vacancy on rutile-TiO2(110), rutile-SnO2(110), and MgO(100) surfaces assuming that the removed O atom remains adsorbed in the neighborhood of the vacancy (surface Schottky defect). The readsorption of the removed O atom considerably reduces the energetic cost of formation of the vacancy. The readsorption process differs from adsorption of atomic oxygen on a nondefective surface. In fact, on a regular surface an O atom binds to an oxide anion and forms a peroxo group, while on a reduced surface the O atom adsorbs preferentially on the metal cation. The study accounts also for the possible formation of formally charged defects (e.g., the F+ center) at the surface of ionic oxides.
Menetrey, M., Markovits, A., Minot, C., Pacchioni, G. (2004). Formation of Schottky defects at the surface of MgO, TiO2, and SnO2: A comparative density functional theoretical study. JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL, 108(34), 12858-12864 [10.1021/jp048497c].
Formation of Schottky defects at the surface of MgO, TiO2, and SnO2: A comparative density functional theoretical study
PACCHIONI, GIANFRANCO
2004
Abstract
We have performed density functional theory-generalized gradient approximation periodic calculations to study the formation of an oxygen vacancy on rutile-TiO2(110), rutile-SnO2(110), and MgO(100) surfaces assuming that the removed O atom remains adsorbed in the neighborhood of the vacancy (surface Schottky defect). The readsorption of the removed O atom considerably reduces the energetic cost of formation of the vacancy. The readsorption process differs from adsorption of atomic oxygen on a nondefective surface. In fact, on a regular surface an O atom binds to an oxide anion and forms a peroxo group, while on a reduced surface the O atom adsorbs preferentially on the metal cation. The study accounts also for the possible formation of formally charged defects (e.g., the F+ center) at the surface of ionic oxides.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.