AVS 50th International Symposium
    Surface Science Thursday Sessions
       Session SS3-ThM

Paper SS3-ThM8
The Oxygen Chemistry of Rutile TiO@sub 2@(110) - A Comprehensive STM Study

Thursday, November 6, 2003, 10:40 am, Room 328

Session: Oxide Structure, Growth, and Defects
Presenter: R. Schaub, Interdisciplinary Nanoscience Center, Denmark
Authors: R. Schaub, Interdisciplinary Nanoscience Center, Denmark
E. Wahlström, Interdisciplinary Nanoscience Center, Denmark
A. Ronnau, Interdisciplinary Nanoscience Center, Denmark
E.K. Vestergaard, Interdisciplinary Nanoscience Center, Denmark
F. Besenbacher, Interdisciplinary Nanoscience Center, Denmark
Correspondent: Click to Email
The detailed understanding of the oxygen chemistry on titanium oxide is an important issue for chemical and photo-chemical processes on this material. We present a thorough high resolution variable temperature STM investigation of the interaction of oxygen molecules with the (110) surface of TiO@sub 2@. Single oxygen molecules interact with oxygen vacancies, mediating their diffusion through a simple oxygen atom exchange mechanism. Surprisingly, this mechanism does not account for healing of the vacancies as speculated in the literature until now. The adsorption of molecular oxygen leads also to the creation of different oxygen-related species, which are readily distinguishable by their contrast in STM images and their dynamics in time-resolved STM experiments. The subtle interaction of these different species present on the surface accounts for the healing of the vacancies through an unanticipated and complex mechanism discussed in detail.