Experimental Determination of Electron Inelastic Mean Free Paths in 13 Elemental Solids in the 50 eV to 5000 eV Energy Range by Elastic-Peak Electron Spectroscopy

Published

May 1, 2005

Author(s)

S Tanuma, T Shiratori, Tetsuya Kimura, K Goto, S Ichimura, Cedric J. Powell

Abstract

We have determined electron inelastic mean free paths (IMFPs) in C (graphite), Si, Cr, Fe, Cu, Zn, Ga, Mo, Ag, Ta, W, Pt and Au by elastic-peak electron spectroscopy (EPES) using Ni as a reference material for electron energies between 50 eV and 5000 eV. These IMFPs could be fit by the simple Bethe equation for inelastic electron scattering in matter for energies from 100 eV to 5000 eV. The average root-mean-square (RMS) deviation in these fits was 9 %. The IMFPs for Si, Cr, Fe, Cu, Ag, Ta, W, Pt and Au were in excellent agreement with the corresponding values calculated from optical data for energies between 100 eV and 5000 eV. While the RMS deviations for graphite and Mo in these comparisons were large (27 % and 17 %, respectively), the average RMS deviation for the eleven elements was 11 %. Similar comparisons were made between our IMFPs and values obtained from the TPP-2M predictive equation for energies between 100 eV and 5000 eV, and an average RMS deviation for the thirteen solids was 10.7 %; in these comparisons, the RMS deviations for Ta and W were relatively large (26 % for each). A correction for surface-electronic excitations was calculated from a formula of Werner et al.; except for Si and Ga, the average correction was 5 % for energies between 150 and 5000 eV. The satisfactory consistency between the IMFPs from our EPES experiments and the corresponding IMFPs computed from optical data indicates that the uncertainty of these IMFPs is about 11 % for electron energies between 100 eV and 5000 eV.

Citation

Surface and Interface Analysis

Volume

37

Pub Type

Journals

Keywords

chromium, copper, elasti-peak electron spectgroscopy, electron inelastic mean free path, gallium, graphite, iron, molybdenum, platinum

Citation

Tanuma, S. , Shiratori, T. , Kimura, T. , Goto, K. , Ichimura, S. and Powell, C. (2005), Experimental Determination of Electron Inelastic Mean Free Paths in 13 Elemental Solids in the 50 eV to 5000 eV Energy Range by Elastic-Peak Electron Spectroscopy, Surface and Interface Analysis (Accessed December 1, 2024)