title: Observation and destruction of an elusive adsorbate with STM: O₂/TiO₂(110).
abstract: When a slightly defective rutile TiO₂(110) surface is exposed to O₂at elevated temperatures, the molecule dissociates at defects, filling O vacancies (V(O)) and creating O adatoms (O(ad)) on Ti(5c) rows. The adsorption of molecular O₂ at low temperatures has remained controversial. Low-temperature scanning tunneling microscopy of O₂, dosed on TiO₂(110) at a sample temperature of ≈100 K and imaged at 17 K, shows a molecular precursor at V(O) as a faint change in contrast. The adsorbed O₂ easily dissociates during the STM measurements, and the formation of O(ad)'s at both sides of the original V(O) is observed.
authors.affiliation: Institute of Applied Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Vienna, Austria.
authors.forename: Philipp
authors.initials: P
authors.lastname: Scheiber
authors.forename: Alexander
authors.initials: A
authors.lastname: Riss
authors.forename: Michael
authors.initials: M
authors.lastname: Schmid
authors.forename: Peter
authors.initials: P
authors.lastname: Varga
authors.forename: Ulrike
authors.initials: U
authors.lastname: Diebold