Influence of adsorbed carbon monoxide molecules on the thermal properties of rare-earth metal ytterbium films of nanoscale thickness has been studied. The films are produced at room temperature by metal deposition on single-crystal silicon substrates with the Si(111) surface orientation or textured tungsten ribbons with the predominant (100) face. It is shown that the adsorbed molecules hinder evaporation of ytterbium. The strength of such hindering is dependent on the chemical nature of substrate material. It is established that the substrates affect the state of adsorbed molecules through the nanofilms. This in turn influences on the evaporation rate of nanolayer material.
The effect of standing waves of charge density (Friedel oscillations) generated by an interface of the ‘metallic ytterbium nanofilm single-crystal silicon substrate’ type on the work function of ytterbium nanolayers has been studied. It is shown that in the range of nanofilm thicknesses from 0 to 8 monatomic layers, the work function has an oscillating character. This feature of the dependence of the work function on the nanofilm thickness is a consequence of the fact that the standing waves change nonmonotonically the power (momentum) of the electric double layer, which exists on the metal surface and affects the work function of the metal. This ultimately determines the oscillating nature of the dependence of the work function on the thickness of the nanofilms.