Electronic structure of vacancies and interstitials in metals

Abstract

Recent work on the electronic structure of point defects in metals is reviewed. The basic ideas of the models most frequently used in studies of vacancies and interstitials are described, but technical aspects of the calculations are avoided. Most calculations have been performed for the simple metals and the emphasis of the paper is on these, but the prospects for studying other metals are discussed. Sophisticated calculations have been performed for vacancies leading to estimations of formation energies and volumes including lattice relaxation. The calculations have had some success, but limitations of the model are now clear and these are described. Comparatively less work has been done on interstitials and most of this has been confined to light interstitials such as hydrogen and helium. However, trends are emerging from the calculations and these are discussed. The extension of the models to treat defect characteristics at elevated temperatures is described.