An ESCA method for determining the oxide thickness on aluminum alloys

A simple method for estimating the oxide thickness on aluminum alloys using ESCA was investigated. The method is based on a uniform overlayer model and requires only a single ESCA measurement per sample. Expressions are shown which relate the experimental intensity ration of the oxidic and metallic Al 2p ESCA peaks to the oxide thickness, for both MG and Al x‐ray sources. The method does not require ion etching or separate calibration procedures. Several practical examples that illustrate the usefulness of this method are presented. The method can also be applied to other thin film (i.e. <∼ 100 Å) metal oxide/metal systems. The maximum oxide thickness that can be measured using the method is limited to approximately three times the inelastic mean free path of the appropriate photoelectrons within the material of interest.