A. Krol, C.J. Sher, et al.
Surface Science
The influence of surface corrections on three-dimensional dislocation dynamics is investigated by considering a curved dislocation intersecting a plane free surface. The Boussinesq-Cerruti formalism is used to determine the image field for this problem to high accuracy. A heuristic method for simultaneously regularizing the self-interaction and the image-field singularity allows curvature and image effects to compete dynamically. Comparison of our implementation against analytical predictions for the critical strain in a strained layer with a free surface yields excellent agreement. We find that while the image corrections determine the angle at which the dislocation enters the boundary, their overall effect on a curved dislocation is surprisingly small, varying from a few per cent for a 1 νm half-loop at the surface to at most 40% for a half-loop with a radius as small as 1 nm. We conclude that for many dislocation problems, especially those involving only a few dislocations in a confined geometry, it is a meaningful first approximation to neglect long-range image effects altogether, the errors becoming large only at scales comparable to the Burgers vector. A useful way of implementing this approximation in the case of a free surface is to estimate an image force using a formula given by Lothe, and apply it to the surface intercept point only. © 2005 IOP Publishing Ltd.
A. Krol, C.J. Sher, et al.
Surface Science
Oliver Schilter, Alain Vaucher, et al.
Digital Discovery
T.N. Morgan
Semiconductor Science and Technology
I. Morgenstern, K.A. Müller, et al.
Physica B: Physics of Condensed Matter