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Determination of photoelectron attenuation lengths in thin oxide films on iron surfaces using quantitative XPS and elastic recoil detection
Author(s) -
Roosendaal S. J.,
Giebels I. A. M. E.,
Vredenberg A. M.,
Habraken F. H. P. M.
Publication year - 1998
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199809)26:10<758::aid-sia425>3.0.co;2-b
Subject(s) - x ray photoelectron spectroscopy , elastic recoil detection , analytical chemistry (journal) , stoichiometry , attenuation length , oxide , chemistry , attenuation , thin film , materials science , nuclear magnetic resonance , optics , nanotechnology , physics , organic chemistry , chromatography
Abstract Thin oxide films play an important role in the corrosion of metals. Using XPS it is possible in principle to obtain information on the chemical state of near‐surface atoms, the stoichiometry of the surface layer and its thickness. A problem is the quantification of XPS spectra, due to the large uncertainty in the value of both electron attenuation lengths as well as sensitivity factors. By applying the Tougaard background subtraction method and comparing only peak intensities of the Fe 2p and O 1s peaks with those of Fe, FeO and Fe 2 O 3 reference samples, we determined the stoichiometry of the oxide layer grown on Fe(100) and Fe(110) at 200°C and room temperature to be Fe 0.90±0.05 O. We combined XPS with the high‐energy ion‐beam technique of elastic recoil detection (ERD). By comparing the absolute coverages of oxygen determined by ERD with the intensities of different XPS peaks, we were able to determine the attenuation lengths for kinetic energies of 776 eV (Fe 2p) and 957 eV (O 1s) to be 9.3×10 15 and 9.9×10 15 Fe 0.9 O molecules cm −2 , respectively. © 1998 John Wiley & Sons, Ltd.