A study was made of several neutral and charged O and Si defects in α-quartz. Plane waves pseudopotential calculations were carried out within the framework of density functional theory in the local density approximation. The structures that were obtained for vacancies and interstitials in several charge states, and the corresponding formation energies, were described. The reciprocal dependence of the formation energies of charged defects (and thus concentrations), and the electron chemical potential on each, were analyzed. The latter were determined by iterative self-consistent solution of the equation, while imposing charge neutrality. Results on defect concentrations, their dependence upon O partial pressure, and self-doping effects were presented.

A First Principles Study of Native Defects in α-Quartz. G.Roma, Y.Limoge: Nuclear Instruments and Methods in Physics Research Section B, 2003, 202, 120-4