It was pointed out that, when an electrical current flowed parallel to a stepped metal surface, each step experienced a force that was due to momentum transfer from the carriers that were diffusely scattered by the step-edge. A ballistic model was used here to compute the wind-force per unit length which acted upon the steps of the vicinal (100) surfaces of Al. Carrier scattering at the surface was described by a potential-barrier model fit to the results of a first-principles calculation of the surface-induced resistivity of the unstepped surface. The magnitude of the wind force was an increasing function of the step terrace-width, and attained a constant value as the steps moved apart. For an isolated step on an Al(100) surface, the effective wind valence per unit length of the step-edge was about -15e/Ǻ. This value was equivalent to a wind valence of about -43e/atom at the leading edge of each step.

Electromigration Wind Force at Stepped Al Surfaces. P.J.Rous: Physical Review B, 1999, 59[11], 7719-23