Article révisé par les pairs
Résumé : The theoretical calculations of the positron response to different types of defects can be very helpful in order to interpret properly positron measurements. In this contribution a new computational technique to determine positron properties in nanocrystalline materials is presented. In such calculations we employ the realistic models of n-materials obtained using molecular dynamics. The new technique is based on the so-called atomic superposition method where atomic densities are superimposed in a selected region of the model (virtual) sample to approximate the electron density of the system. We study the virtual samples of n-Cu, n-Ni, n-NiAl, and n-Ni3Al, for which we calculate positron lifetimes and positron binding energies corresponding to defects located in selected regions of the samples. The regions of interest for positron calculations comprise grain boundaries including triple points, nano-voids, and bulk-like regions. © 2001 Materials Research Society.