AVS 50th International Symposium
    QSA-10 Topical Conference Tuesday Sessions
       Session QS-TuP

Paper QS-TuP4
Experimental Determinations of Electron Inelastic Mean Free Paths in Ten Elemental Solids from Elastic Peak Intensities

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Aspects of Quantitative Surface Analysis
Presenter: S. Tanuma, National Institute for Materials Science, Japan
Authors: S. Tanuma, National Institute for Materials Science, Japan
T. Kimura, National Institute for Materials Science, Japan
K. Goto, Nagoya Institute of Technology, Japan
S. Ichimura, National Institute for Advanced Industral Science, Japan
Correspondent: Click to Email
The values of electron inelastic mean free paths (IMFPs) are very important physical quantity for surface analyses by AES and XPS. In usual, they have been determined from the theoretical calculations because the reliable experimental determinations of IMFP is rather a complicated work. The elastic-peak electron spectroscopy (EPES) is an efficient tool for experimental determination of IMFPs. This method, however, requires a reference specimen to obtain the values of IMFPs and gave different values according to the used reference specimen. On the other hand, absolute elastic-peak measurement method, which is carried out with a novel cylindrical mirror analyzer equipped with a Faraday cup, does not need the reference specimen. However, this method needs the surface plasmon excitation correction. Then, we have measured the IMFPs for Si, Zn, Cu, Ag, Ta, W, Au, Mo, Fe and Pt using Ni reference in the range 50 -2000 eV and compared with the IMFPs determined from theoretical calculations and absolute elastic-peak method using Oswald surface excitation correction. The experimental elastic peak intensity rations of above elemental solids to Ni-reference are in excellent agreement with those of Monte Carlo calculations from TPP-2M and from theoretical IMFPs (Penn algorithm) in the 200 - 5000 eV energy range. Under 200 eV, however, the measured intensity rations of them did not coincide well with the calculated result, which was mainly due to the surface excitation effects and the uncertainty of used elastic scattering cross sections.