The Energetics of Defects and Impurities in Metals and Ionic Materials from First Principles

De Vita, Alessandro

Abstract

The study of defects in metals and ionic solids has been the subject of great theoretical and experimental interest, in basic as well as applied research areas. The present work collects two series of calculations on the energetics of a variety of defective systems, in a metal host matrix (Al), and in two ionic oxides (MgO and Li2O) . The energetics and the electronic ground state of the vacancy, of the self-interstitial, and of the hydrogen impurity systems in Al were investigated. The formation and migration energies of Schottky defects in MgO and Frenkel Defects in Li2O were also studied. All results are in close agreement with experiment, while the work gives new insight into the localisation of defects, the role played by lattice relaxation effects, and the defectinduced redistribution of valence electrons. The calculations are based on density functional and pseudopotential theory, make use the supercell approach, and employ in different implementations the conjugate gradients technique to minimise the total energy functional. For the calculations on oxides, we made use of a newly developed parallel computing methodology.

Citation

De Vita, A. (1992). The Energetics of Defects and Impurities in Metals and Ionic Materials from First Principles. (Thesis). Keele University. https://keele-repository.worktribe.com/output/1240616

• Thesis Type: Thesis
• Online Publication Date: May 23, 2025
• Deposit Date: May 23, 2025
• Publicly Available Date: May 23, 2025
• Keywords: Department of Physics.
• Public URL: https://keele-repository.worktribe.com/output/1240616
• Award Date: 1992