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Auger electron appearance potential spectroscopy study of CrN x films
Author(s) -
Chourasia A. R.,
Hood S. J.
Publication year - 2001
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/sia.991
Subject(s) - chromium , x ray photoelectron spectroscopy , analytical chemistry (journal) , auger electron spectroscopy , binding energy , chromium nitride , electron spectroscopy , fermi level , density of states , chemistry , nitrogen , spectroscopy , nitride , materials science , atomic physics , electron , metallurgy , nuclear magnetic resonance , physics , condensed matter physics , nuclear physics , organic chemistry , chromatography , layer (electronics) , quantum mechanics
Abstract Thin films of chromium nitride deposited with varying concentrations of nitrogen on stainless steel substrates have been studied using Auger electron appearance potential spectroscopy (AEAPS). This technique provides information on the density of states in the conduction band. The chromium L 2,3 levels have been investigated. The normalized AEAPS chromium spectra in the films have been compared with the elemental chromium spectrum. The signal strength at the Fermi level ( E F ) is observed to be larger in the films. This represents an increase in the density of states at E F for the films as compared with that of elemental chromium. However, in the films, the density of states is found to decrease with increasing nitrogen concentration. The binding energy of the chromium L 3 level for the films exhibits a positive chemical shift with respect to elemental chromium. These spectral data indicate a direction of charge transfer from chromium to nitrogen. In the films, the charge transfer is observed to decrease with increasing nitrogen content. We also present a scheme to estimate the Coulomb correlation energy using the chromium L 3 core‐level binding energy data obtained from AEAPS and x‐ray photoelectron spectroscopy (XPS). A decrease in the correlation energy with increasing nitrogen content is observed for the films. We also have estimated the total density of unoccupied states above E F from the experimental data. This total density is observed to be more in the films than in elemental chromium. In the films, the total density of states decreases with nitrogen concentration. The AEAPS spectral results have been correlated with our earlier XPS results on these films. Copyright © 2001 John Wiley & Sons, Ltd.