When a slightly defective rutile TiO2(110) surface is exposed to O2 at elevated temperatures, the molecule dissociates at defects, filling O vacancies (\ov) and creating O adatoms (\oad) on {\tifc} rows. The adsorption of molecular O2 at low temperatures has remained controversial. Low-Temperature Scanning Tunneling Microscopy (LT-STM) of O2, dosed on TiO2(110) at a sample temperature of ≈ 100 K and imaged at 17 K, shows a molecular precursor at \ov as a faint change in contrast. The adsorbed O2 easily dissociates during the STM measurements, and formation of \oad's at both sides of the original \ov is observed.
@article{arxiv.1009.1479,
title = {Observation and destruction of an elusive adsorbate with STM: O$_2$/TiO$_2$},
author = {Philipp Scheiber and Alexander Riss and Michael Schmid and Peter Varga and Ulrike Diebold},
journal= {arXiv preprint arXiv:1009.1479},
year = {2010}
}
Comments
Submitted to Physical Review Letters. 4 pages, 2 figures