Субмонослойные покрытия натрия на поверхности золотой пленки

Abstract

n situ photoelectron spectroscopy studies have been carried out in ultrahigh vacuum of the electronic structure of a 2D Au film deposited on a surface W with a natural oxide, before and after adsorption of Na atoms. The spectra of photoemission from the valence band and core levels of Au 4f, W 4f and Na 2p were studied under synchrotron excitation in the photon energy range of 120-300 eV. The investigated 2D Au film with a thickness of 0.83 nm has a valence band close to the valence band of the massive sample. The diffusion of Na atoms deep into the gold film was not detected, which indicates the layered growth of the 2D Au film. Two states have been found: Nadelta+ and Na+, which exist even with a 0.15 sodium coating of the monolayer, which indicates the formation of Na islands and single adsorption of Na atoms. The density functional method is used to calculate the electronic structure of a 2D Au layer without and with adsorbed Na. It is established that the adsorption of Na atoms in the pit or bridge position is preferable. It is found that the adsorption of Na leads to the reconstruction of the surface.