Chemical reactions at surfaces: titanium oxidation

VAQUILA, I.; VERGARA, L.I.; PASSEGGI (JR.), M.C.G.; VIDAL, R.A.; FERRÓN, J.

Rosario (Santa Fe), Argentina, 14-18 Septiembre

Jornada; Jornadas SAM1998, IBEROMET V; 1998

Sociedad Argentina de Metales

Auger electron spectroscopy has been used to study the first stages of titanium oxidation. Titanium at room and high temperature, as well as thin films deposited over a metal substrate, were oxidized at low pressure. The authors found, using factor analysis, two different regimes depending on the sample temperature. For temperatures below 200°C the oxidation is characterized by the presence of only one oxide phase: TiO2. At higher temperatures, the presence of Ti2O3 is detected from the beginning of the process. For thin films [less than one monolayer (ML)] only TiO2 was found, but for thicker films a new oxide phase is detected (TiOx, x<2). Finally, for thicknesses >7 ML, only TiO2 is detected.