Calculations of Electron Inelastic Mean Free Paths. VIII. Data for 15 Elemental Solids Over the 50 eV to 2000 eV Range

Published

January 1, 2005

Author(s)

S Tanuma, Cedric J. Powell, David R. Penn

Abstract

We report calculations of electron inelastic mean free paths (IMFPs) for 50 eV to 2000 eV electrons in 14 elemental solids (Li, Be, diamond, graphite, Na, K, Sc, Ge, In, Sn, Cs, Gd, Tb, and Dy) and for one solid (Al) using better optical data than in our previous work. The new IMFPs have also been used to test our TPP-2M equation for estimating IMFPs in these materials. We found surprisingly large root-mean-square deviations (from 39.3 % to 71.8 %) between IMFPs calculated from TPP-2M and those calculated here from optical data for diamond, graphite, and cesium. An analysis showed that these large deviations occurred for relatively small computed values of the parameter β in the TPP-2M equation (β 0.01 for diamond and graphite) and for a relatively large value of β (β 0.25 for Cs). While such extreme values of β are unlikely to be encountered for many other materials, the present results indicate an aditional limitation in the reliability of the TPP-2M equation. We also show that the parameter N_v in the TPP-2M equation should be computed for the rare-earth elements from the number of valence electrons and the six 5p electrons.

Citation

Surface and Interface Analysis

Volume

37 No. 1

Pub Type

Journals

Keywords

Auger electron spectroscopy, cesium, diamond, electron inelastic mean free path, graphite, surface analysis, x-ray photoelectron spectroscopy

Citation

Tanuma, S. , Powell, C. and Penn, D. (2005), Calculations of Electron Inelastic Mean Free Paths. VIII. Data for 15 Elemental Solids Over the 50 eV to 2000 eV Range, Surface and Interface Analysis (Accessed November 8, 2024)