The Contribution of Auger Spectroscopy to the Study of Core Hole Screening and Electron Correlation in Alloys

In principle the electron spectra of Auger transitions which create final-hole states in atomic valence levels can yield information on the local electronic structure of the atomic environment. Unfortunately the most interesting Auger transitions involving valence levels are often weak and progress in this branch of electron spectroscopy has depended on the development of high sensitivity electron spectrometers. Fortunately great advances have been made in instrumentation in the last ten years and Auger spectroscopy is now beginning to show its potential as a probe of local electronic structure. In this work an account will be given of recent work on alloy systems in which Auger spectroscopy has been used to determine electron correlation energies and the nature of the screening charge around impurities and core-ionised atoms.