Calculations of Electron Inelastic Mean Free Paths (IMFPs) V. Data for 14 Organic Compounds over the 50-2000 eV Range

Published

September 14, 1994

Author(s)

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

Abstract

We report calculations of electron inelastiv mean free paths (IMFPs) of 50-2000 eV electrons for a group of 14 organic compounds: 26-n-paraffin, adenine, β-carotene, bovine plasma albumin, deoxyribonucleic acid, diphenylhexatriene, guanine, kapton, polyacetylene, poly(butene-1-sulfone), polyethylene, polymethylmethacrylate, polystyrene, and poly(2-vinylpyridine). The computed IMFPs for these compounds showed greater similarities in magnitude and in the dependences on electron energy than was found in our previous calculations for groups of elements and inorganic compounds (Papers II and III in this series). Comparison of the IMFPs for the organic compounds with values obtained from our predictive IMFP formula TPP-2 showed systematic differences of 40%. These differences are due to the extrapolation of TPP-2 from the regime of mainly high-density elements (from which it had been developed and tested) to the low-density materials such as the organic compounds. We analyzed the IMFP data for the groups of elements and organic compounds together and derived a modified empirical expression for one of the parameters in our predicitive IMFP equation. The modified equation, denoted TPP-2M, is believed to be satisfactory for estimating IMFPs in elements, inorganic compounds and organic compounds.

Citation

Surface and Interface Analysis

Volume

21

Issue

3

Pub Type

Journals

Citation

Tanuma, S. , Powell, C. and Penn, D. (1994), Calculations of Electron Inelastic Mean Free Paths (IMFPs) V. Data for 14 Organic Compounds over the 50-2000 eV Range, Surface and Interface Analysis (Accessed November 8, 2024)