The phenomenology of the adsorption of Fe adatoms and ad-dimers and the diffusion of Fe adatoms on an ultra-thin titanium oxide monolayer grown on the Pt(111) surface was investigated via density functional simulations. It was found that (i) Fe atoms adsorbed on 3-fold hollow sites or defective holes of the oxide slab with interaction energies ranging from 2.3 to 4.7eV; (ii) Fe dimers adsorbed with proportional energetics and a clear preference for horizontal rather than vertical configurations; (iii) Fe atoms diffused over the oxide surface with energy barriers ranging from ̃0.7 to 1.1eV on compact regions to 1.6 to 2.0eV on defective regions of the film. This pointed to a great importance of kinetic effects in the growth of Fe clusters on this surface; much greater than in the previously investigated cases of noble or quasi-noble metals such as Au and Pd.

Adsorption and Diffusion of Fe on a Titania Ultrathin Film. Barcaro, G., Fortunelli, A.: Journal of Physical Chemistry A, 2009, 113[52], 14860-6