Abstract:
The effect of chemisorbed oxygen molecules on the electron structure of ytterbium films of nanosized thicknesses has been studied by means of high-resolution photoelectron spectroscopy. It has been demonstrated that, in the process of chemisorption of O$_2$ molecules, the subsurface layers of ytterbium films transform from a two-valence state into a three-valence one. Estimation of the depth of disturbance induced by molecules has been performed. The estimates reveal that the above depth can attain very large values: up to 22 film layers, or 7.5 nm.