Paramagnetic structure for the soliton of the $30^\circ$ partial dislocation in silicon

TL;DR

This paper proposes a new atomic structure for a fundamental defect in silicon dislocations, linking it to experimental ESR signatures and enabling better understanding of silicon's plastic deformation.

Contribution

It introduces a novel paramagnetic soliton structure for the 30° partial dislocation in silicon based on ab initio calculations, connecting theory with ESR observations.

Findings

Identified a five-fold coordinated atom near the dislocation core.

Linked the defect's electronic structure to the ESR signature of the R center.

Suggested experimental methods to measure soliton density.

Abstract

Based on ab initio calculation, we propose a new structure for the fundamental excitation of the reconstructed 30$^\circ$ partial dislocation in silicon. This soliton has a rare structure involving a five-fold coordinated atom near the dislocation core. The unique electronic structure of this defect is consistent with the electron spin resonance signature of the hitherto enigmatic thermally stable R center of plastically deformed silicon. This identification suggests the possibility of an experimental determination of the density of solitons, a key defect in understanding the plastic flow of the material.