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

摘要

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