Inelastic neutron scattering from screw dislocations

Publisher Website
Google Scholar
Abstract
The phonon dispersion curves of the localized modes associated with a screw dislocation in a model simple cubic lattice are calculated by employing the approach of Tewary (1974) and by numerical evaluation of the Green function. The imperfect-lattice Green function for the model crystal containing a random array of screw dislocations is derived, and with it an expression for the cross section for inelastic neutron scattering by the dislocation-associated modes is found. The numerical evaluation of the cross section and of the frequency shifts away from the one-dislocation values has been carried out for several scattering directions. The calculations are performed over a range of values of the free parameters: the dislocation density and the longitudinal and transverse force-constants.