Pressure effects on self-diffusion in silicon

Abstract

The effects of hydrostatic pressure on the energetics of self-diffusion in silicon are investigated via parameter-free total-energy calculations. The three microscopic mechanisms, vacancy, interstitial, and concerted exchange, which have very similar activation energies in Si, exhibit different pressure dependences. The results suggest that a set of experiments carried out at different pressures can unravel their relative contributions by a comparison to the present results. In addition, it is shown that in contrast to the (111) surface, the nearest neighbors of the Si vacancy relax inwards, rather than outwards.