Silicon thin films for coverages (θ) between 0.3 and 3 monolayers have been grown on rutile \ce{TiO2}(110)-(1x1) at room temperature and studied by x-ray and ultra-violet photoelectron spectroscopies, Auger electron spectroscopy, and low energy electron diffraction (LEED). A clear evidence of a strong \ce{Si}/\ce{TiO2} interaction consistent with the high affinity of O for Si has been found. The Ti cations on the substrate are reduced, while the Si film is oxidized, yielding \ce{SiO2} and a mixture of silicon suboxides. Neutral Si atoms are observed at a coverage of 3 monolayers. At the interface region we observe the formation of cross-linking Ti-O-Si bonds. The thin Si overlayer strongly attenuates the (1×1) LEED pattern from the substrate. Finally, thermal annealing results in the improvement of the \ce{SiO2} stoichiometry, but the surface order is not recovered. Using ab-initio density functional theory we have obtained optimum geometrical configurations and corresponding density of states for 1/3 \le \theta \le 1monolayersofSiadsorbedonthe1 \times 1$ two-dimensional unit cell.
@article{arxiv.1106.0388,
title = {Characterization of silicon thin overlayers on rutile \ce{TiO2} (110)-(1x1)},
author = {J. Abad and C. Gonzalez and P. L. de Andres and E. Roman},
journal= {arXiv preprint arXiv:1106.0388},
year = {2011}
}