Nanocomposite thin films composed of a TiO2 matrix doped with noble metals nanoparticles (MNPS), Au and Ag, were deposited on Si (100) and glass substrates by dc magnetron sputtering. The samples were annealed in a protective atmosphere at temperatures
ranging from 200 to 700 ºC. The main goal of this work is to characterize and compare the Surface Plasmon Resonance (SPR) behaviour in both systems. The studies have been focused on the growth of the nanoclusters and on their role on the optical properties of the films. Size, shape and distribution of the nanoclusters embedded on the titanium oxide dielectric matrix are reported as key factors on the SPR behaviour in both systems (Au:TiO2 and Ag:TiO2). The MNPs grew due to diffusion mechanisms, which were led by the annealing treatments, even at the highest annealing temperatures. Evidences of the correlation between the nanocomposite film structural changes and the evolution of the optical properties due to the SPR activity are reported. The SPR phenomenon manifests itself as a wide band on the visible range on the absorption spectra, and it is confirmed by
an important change on the surface colour tones of the samples.This research is sponsored by FEDER funds through the program COMPETE - Programa
Operacional Factores de Competitividade and by national funds through FCT - Fundação para a
Ciência e a Tecnologia, under the project PTDC/CTM/ 70037/2006 70037/20B and also UB-SCT
(Barcelona) for the TEM characterization
