SIMULTANEOUS DETERMINATION OF COMPOSITION AND THICKNESS OF THIN IRON-OXIDE FILMS FROM XPS FE 2P SPECTRA

The composition and thickness of thin iron-oxide films on pure iron we re determined from XPS Fe 2p spectra. To this end the spectra were rec onstructed from reference spectra for Fe-0, Fe2+ and Fe3+. The appropr iate background due to inelastically scattered electrons was calculate d for each reference spectrum, using a recent generalization of Tougaa rd's method. For the reconstruction the film thickness and the relativ e amounts of Fe2+ and Fe3+ in the oxide film were used as fit paramete rs. A good agreement was obtained between experimental and reconstruct ed spectra.