THE EFFECT OF ELECTRONIC LOCALIZED STATES AT DISLOCATIONS ON THE CHEMICAL IMPURITY-DISLOCATION INTERACTION

The electronic contribution to the interaction energy between impuriti es and edge dislocations, which is related to the existence of localiz ed electronic states at the dislocation, is calculated within the fram ework of a simple model. It is shown that the interaction energy varie s within the limits of 10(-2)-10(-1) of the bandwidth and depends esse ntially on the lattice structure, the Burgers vector b, the type of im purity ('donor' or 'acceptor') and on the conduction-band filling. The se effects are expected to be important in intermetallics with the B2 structure, where plastic deformation is governed by dislocations with b = a(100) (NiAl, CoAl, etc.).