TiCl4(THF)(2) was impregnated by spin-coating on a Si(100) wafer covered with a thin SiOx layer and on a polycrystalline Au foil. The nature of the surface species was determined at room temperature and after annealing, by X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). A mixed Si:O:Ti interfacial layer was formed on the silicon substrate while in the case of Au, TiOClx and TiOx were the main surface species at room temperature. Annealing at 723 K leads to the total desorption of the Cl atoms, and in both cases a significant amount of Ti atoms was reduced to the Ti3+ state. AFM measurements revealed a homogenous distribution of nano-sized TiOx clusters with semi-ellipsoid shape and increased contact area with the underlying silica. (C) 2004 Elsevier B.V All rights reserved.