L.V.Yashina, E.V.Tikhonov, V.S.Neudachina, T.S.Zyubina, A.N.Chaika, V.I.Shtanov, S.P.Kobeleva, Yu.A. Dobrovolsky. The oxidation of PbTe(100) surface in dry oxygen. Surface and Interface Analysis, 2004 (in press)

Abstract

The oxidation of PbTe (100) surface in dry oxygen was studied by means of XPS. The appearance of a Te⁴⁺ component in Te3d spectra and an additional component shifted to 1 eV in Pb 4f spectra was observed. It was revealed that at exposures 10¹¹-10¹⁵L the oxidation mechanism does not change. The oxidation product stoichiometry is close to PbTeO₃. Quantum chemical modelling of the interaction of small cluster (PbTe)₄ with one oxygen molecule was performed in the frames of density functional theory (B3LYP). It was revealed that Pb-O (2.22-2.43Å) and Te-O (1.97Å) bonds are formed during the energetically favorable chemisorption process, this leading to the increase of Pb and Te effective Mulliken charges by +0.18-0.31e and +1.11e, respectively. These changes are in good correlation with the observed binding energies for additional components in the XPS spectra of the oxidized surface.