The strategy to study the initial stages of oxidation of TiAl involved gaining first some information on the electronic structure of pure TiO2 surface and then on TiAl surface before and after oxidation. Both materials were studied in cleaned states generated by repeated sputtering and heating. The results on the initial stage of oxidation of TiAl confirm the nucleation of Ti203 islands with nanometer size and monolayer height. The ledges acted as nucleation sites. The oxygen vacancies created additional defect states in the band gap of stoichiometric TiO2.
Keywords: STM, TiO2, TiAl, oxidation