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Title:Core-valence-valence auger spectra of the simple metals
Author(s):Davis, Linda Rae
Doctoral Committee Chair(s):Wortis, M.
Department / Program:Physics
Subject(s):core-valence-valence (CVV)
Auger line spectra
simple metals
many-body models
free-electron theory
Abstract:A comprehensive study of the core-valence-valence (CVV) Auger line shapes for the simple metals, Li, Be, Na, Mg, and AI, is presented. Calculations of these line shapes are performed with a static many-body model which treats the (static) screening of a core hole by conduction electrons with a phenomenological potential. Our model is applicable only to the simple metals, because free-electron theory is used to describe the conduction electrons. The model is implemented with a finite-particle, determinantal approach, and many-body Auger matrix elements are calculated explicitly using a local approximation. The many-body effects which arise from the core-conduction interaction are treated exactly within the model. The dependence of the model line shapes (i) on parameters specifying the metal and core level, (ii) on approximations of the model, and (iii) on the many-body effects produced by the core-conduction interaction are examined in detail. Also, model calculations of the simple-metal CVV spectra for which data exist are presented. Empirical fits of the model calculations to reported data are achieved for the Li(KVV), Be(KVV), Mg(L2,3VV), and Al(L2,3VV) spectra. In all of these cases, the screening of the core hole by conduction electrons is found to have both s-like and p-like character. One-electron and static many-body calculations have also been performed by other authors for some of the simple-metal spectra. Our model and results are compared to those from the other calculations. Although one-electron theory has reproduced several of the reported simple-metal line shapes, our calculations are the only many-body calculations to produce line shapes in agreement with data. Model calculations for the final reported spectrum, the Mg(KVV), are not presented, because the Mg K core hole is not sufficiently long-lived for our model to be valid. Our expectations concerning the unreported Na(L2,3VV) spectrum are discussed. From our empirical fits and model study, we conclude that the many-body effects which are introduced by the core-conduction interaction, although weak, significantly influence the CVV line shapes of the simple metals. This conclusion is suggestive of the inadequacy of the one-electron theory of CVV line shapes, even in cases of simple-metal spectra.
Issue Date:1986
Genre:Dissertation / Thesis
Rights Information:1986 Linda Rae Davis
Date Available in IDEALS:2011-06-03
Identifier in Online Catalog:891651

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