Initial stage of oxidation of titanium

The electronic structure of titanium with different oxidation levels of the surface was studied by photoelectron spectroscopy and electron energy loss spectroscopy (EELS). The spectra of the valence band and the core level of Ti3p and EEL spectra were recorded for a titanium surface with oxidation exposures from 0.12 to 900 L at room temperature. In general, the titanium oxidation process is similar to that for zirconium, which was investigated earlier; however, certain features of the electronic structure that were not observed earlier were revealed for titanium. Even at high oxidation exposures of ∼1000 L, both O2p valence band and valence band corresponding to titanium metal states were observed. During consecutive oxidation, one can see four different positions of the Ti3p peak corresponding to titanium atoms with different valences. It is probable that, at the initial oxidation stage, islands of complex composition oxide were formed on the surface and grew into the bulk during further oxidation.