Nanocrystalline SnO2 thin films were synthesized by Chemical Vapor Deposition on Si(100) and Al2O3 substrates using bis(diethylamino)dimethylstannane(IV) [(CH3)2Sn(N(C2H5)2)2] as precursor. Film growth was performed at 400-500°C in an O2(H2O)+N2 atmosphere, with the aim of studying the effects of the synthesis conditions on the coating properties. The sample chemical composition and surface morphology were analyzed by X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM), while their structural features were investigated by Glancing Incidence X-ray Diffraction (GIXRD) and X-ray Reflectivity (XRR). In this paper, the attention is focused on the interplay between film nanostructure and morphology, with particular regard to the influence of the growth surface.

TiO2and W:TiO2 thin films have been prepared by a chemically modified sol-gel technique, that implies hydrolysis and condensation of tetraethylortotitanate in the presence of a polymer dissolved in ethanol. Oxide-polymer films were deposited by dip-coating. Annealing at 500°C results in nanosized structurally stable oxides films. For doping tungsten(V)ethoxide was used in concentration that led to a final W/Ti atomic ratio of 1/33, 5/33, 10/33. The morphological and structural characteristics of thin films were studied through microraman, GIXRD, SEM and TEM. A microstructural comparison between pure and doped TiO2 layers is reported. Ethanol and methanol sensing properties are tested.

The influence of the niobium content on the anatase-to-rutile phase transition in nanopowders of Nb–Ti oxides was studied and the changes in the particle size and microstrain distribution obtained at different temperatures were analyzed. A correlation is found between the initial microstructure in the Ti1 – xNbxO2 (x = 0.03, 0.2) powder and the niobium content. The presence of Nb was found to inhibit the growth of both the anatase and the rutile phases.

Thin films of the Ti-W-O system grown by r.f. reactive sputtering from a Ti-W (10%–90% weight) target have been studied by Raman and microraman spectroscopy, X-ray diffraction and scanning electron microscopy with the aim to investigate their microstructural and morphological properties. To this purpose, the kinetics of structural transformations at different temperatures (600 °C, and 800 °C) have been studied, and the effect of Ti on the WO3 lattice has been singled out. The results show that annealing at different temperatures induces a microstructural evolution from the amorphous phase of the as-deposited thin film to WO3 crystalline phases via an intermediate cubic disordered phase of WO3. The effect of Ti on this cubic phase and on the thin film morphology is also investigated with the aid of microraman and scanning electron microscopy analysis. The results show that two distinct phases arise upon long annealing treatments; namely, small crystallites belonging to the WO3 monoclinic phase are dispersed on a layer composed of a disordered cubic WO3 phase with a high Ti content.