Lattice Relaxations near a Vacancy or Interstitial in Aluminum

Publisher Website
Google Scholar
Abstract
The method of lattice statics is applied to calculate the lattice relaxations in the vicinity of a vacancy or an interstitial defect in aluminum. A least-squares fit to the phonon spectrum obtained by Stedmann and Nilsson was used, in conjunction with the elastic constants as constraints, to derive the dynamical matrix including up to eighth-neighbor interactions. The interionic interaction was obtained by using Harrison's model pseudopotential, with parameters adjusted to give a best fit with the phonon data. For a vacancy, the relaxations are found to be 2% (of the lattice constant) or smaller. For the nominal interstitial, the first neighbors are found to relax by 17% and the rest of the neighbors by 3% or less.