Valence transition investigation in the O2–Yb–Si(111) system by means of the angle-resolved photoelectron spectroscopy method

Abstract

Investigations of the Yb–Si(111) and O₂–Yb–Si(111) structures are carried out by means of the angle-resolved photoelectron spectroscopy method, and data about distribution of two- and three-valence ions in ytterbium nanofilms are obtained in the case when an adsorbed molecules layer on their surface is not fully formed yet, and Yb²⁺ → Yb³⁺ valence transition is not completed. It is shown that distribution of Yb²⁺ and Yb³⁺ ions deep into the nanofilms is close to isotropic, and that its spread is 9 or more monolayers. The obtained results indicate that all atoms of the nanofilm participate in formation of the ytterbium 5d band, stimulated by adsorbed molecules, confirming assumptions made in earlier publications.