Nanometer-sized titanium dioxide (TiO(2)) particles were prepared on carbon substrates by reactive direct-current magnetron sputtering. By performing measurements with high resolution electron microscopes, the mean narroparticle diameter and the coverage fraction of the substrate by the nanoparticles (NPs) were measured at 19 nm and 30%, respectively. Moreover, electron diffraction analysis showed that the TiO(2) NPs' crystalline structure on the carbon substrate was a mixture of anatase and rutile. Finally, we provided information on the TiO(2) initial growth stage: crystalline NPs were formed after deposition of amorphous nanoparticles on the substrate and heating. (C) 2009 Elsevier B.V. All rights reserved.