Quantitative analysis of adsorbed layers by Auger electron spectroscopy

A mathematical analysis is presented which enables a simple quantitative characterization of adsorbed layers on a homogeneous substrate. Two main cases are considered: submonolayer coverage by one kind of species (atoms or molecules) and coverage by two different species adsorbed one on top of the other. In both cases, a single Auger spectrum is sufficient to provide the information needed to determine the coverage. The analysis is applied to the case of simultaneous hydrocarbon and oxygen adsorption on polycrystalline silver. The coverage so determined agrees very well with that derived from measurements of adsorption as a function of exposure.