Electromigration in dilute body-centred cubic alloys

A multiple-scattering theory for the wind force in dilute substitutional alloys is applied as an ab initio method to body-centred cubic (BCC) metals. Results are given for self-electromigration in the alkali metals and the group IIA, IVA, VA and VIA metals. For many transition metal systems, the wind force is found to point in the direction of the electric field, which is in agreement with experiment and which could not be reproduced by simpler electronic structure models used in the past. The specific role of the vacancy in the scattering process, leading to the wind force at the initial position of a migrating atom, is made explicit for the group VA metal V. Migration of 3d, 4d and 5d impurities in the metals V, Nb and Ta is studied systematically.