Structure, barriers and relaxation mechanisms of kinks in the 90-degree partial dislocation in silicon

Abstract

Kink defects in the 90-degree partial dislocation in silicon are studied using a linear-scaling density-matrix technique. The asymmetric core reconstruction plays a crucial role, generating at least four distinct kink species as well as soliton defects. The energies and migration barriers of these entities are calculated and compared with experiment. As a result of certain low-energy kinks, a peculiar alternation of the core reconstruction is predicted. We find the solitons to be remarkably mobile even at very low temperature, and propose that they mediate the kink relaxation dynamics.

4 pages in a two column gzipped postscript file (128 K), containing 3 figures and one table. Submitted to Phys. Rev. Lett

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