Extra‐atomic relaxation energies and auger parameters of titanium compounds

Abstract

A series of titanium compounds have been studied by x-ray photoelectron spectroscopy within the Auger parameter formalism. Two different titanium Auger parameters are reported, both calculated from binding energies resulting from photoemission from Ti 2p3/2 core-level states. Of the two values, one has been commonly used for titanium Auger parameter analysis and involves a valence-level Auger transition (L3M2,3Mv), whereas the other is based purely on core-level transitions (L3M2,3M2,3). Both parameters correlate roughly with each other and with extra-atomic relaxation energies calculated from surrounding nearest-neighbor anion polarizabilities. However, the core-level-based Auger parameter shows significantly better correlation with predicted relaxation energy values, particularly when corrections are made for M2,3 multiplet splittings in the analysis. The ability to model extra-atomic relaxation with polarization energies suggests that the ligand polarizabilities in titanium thin-film and powder samples may be estimated reliably from Auger parameter data despite the high degree of covalent character found in many of these compounds. Copyright © 1999 John Wiley & Sons, Ltd.