Evaluations were made of the change in barrier height in the case of an atom jumping to the nearest vacancy site under an imposed strain, and of vacancy diffusion under the influence of strain. Previously, a new approach to solving the problem of the influence of elastic stress upon the vacancy jump-rate for atomic diffusion in crystals had been suggested. This was based upon the simple observation that a stress field altered the surrounding configuration, and upon the assumption that the height of the activation barrier should be altered accordingly. The change in the activation barrier was shown to depend upon the displacement field, the symmetry of the crystal, the atomic structure near to point defects and the interatomic potential. Knowledge of this change made it possible to calculate the jump rate. The expression for the vacancy flux was obtained, with the help of the so-called hole gas method, by using the jump rate. In these non-linear equations, the influence of the strain tensor component upon the diffusion flux was determined by coefficients which depended upon the atomic interaction and atomic structure of the saddle-point configuration.

Diffusion Under a Stress in FCC and BCC Metals. A.V.Nazarov, A.A.Mikheev: Journal of Physics - Condensed Matter, 2008, 20[48], 485203