The effect of electronic localized states at dislocations on the 'chemical' impurity-dislocation interaction

The electronic contribution to the interaction energy between impurities and edge dislocations, which is related to the existence of localized electronic states at the dislocation, is calculated within the framework of a simple model. It is shown that the interaction energy varies within the limits of 10(-2)-10(-1) of the bandwidth and depends essentially on the lattice structure, the Burgers vector b, the type of impurity ('donor' or 'acceptor') and on the conduction-band filling. These 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.).