Mechanisms of formation and the electronic properties of the Yb-Si(100) thin-film system

The formation and properties of the Yb-Si(100) thin-film system were studied by high-resolution photoelectron spectroscopy with synchrotron radiation, Auger electron spectroscopy, the contact potential difference technique, and low-energy electron diffraction measurements over a wide range of coverages and at different temperatures. It was established that the formation of the Yb-Si(100) system prepared by solid-phase epitaxy occurs through a mechanism close to the Stranski-Krastanow mechanism. It was shown that, at submonolayer coverages, it is primarily these two-dimensional (2D) 2 × 3 and 2 × 6 structures that are formed, while at higher coverages a three-dimensional Yb silicide film grows. Data on the morphology and phase composition of the silicide film and on the electronic state of the Si atoms and the valence state of the Yb atoms in the silicide and the 2D structures, as well as on the atomic structure of these films, were obtained. The components of the Si 2p spectra were studied for different coverages. The relation between the shape of these spectra obtained for multilayer Yb silicide films and their phase composition was revealed.