Tc. Lin et al., A CONSISTENT METHOD FOR QUANTITATIVE XPS PEAK ANALYSIS OF THIN OXIDE-FILMS ON CLEAN POLYCRYSTALLINE IRON SURFACES, Applied surface science, 119(1-2), 1997, pp. 83-92
Citations number
41
Categorie Soggetti
Physics, Condensed Matter","Chemistry Physical","Materials Science, Coatings & Films
We report a method for the quantitative analysis of the Fe(2p) and O(1
s) core level XPS spectra which allows the determination of the Fe2+/F
e3+ ratio within a thin oxide film. The method involves the determinat
ion of the intensity of specific shake-up features within the Fe(2p) s
pectrum. This analytical method is demonstrated by comparing the Fe(2p
) spectra of electrochemically modified Fe2+-rich and Fe3+-rich electr
odes in a combined UHV-XPS-electrochemical system. Exposure of clean p
olycrystalline Fe surfaces to low pressures of O-2 gas for different t
ime intervals has also been carried out. Quantitative XPS analyses of
the oxide films produced by O-2 exposures reveal that the oxide films
are predominantly trilayers of FeO, Fe3O4 and FeOOH phases, the latter
due to ambient background contamination. The analyses demonstrate tha
t a multiplicity of Fe2+ and/or Fe3+ chemical environments and binding
energies is present in such films, and this must be explicitly accoun
ted for during quantitative analyses. (C) 1997 Elsevier Science B.V.