Studies of the nonautonomous state of ytterbium nanofilms induced by chemisorbed oxygen molecules by means of photoelectron spectroscopy

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.