Applicability of molecular statics simulation to partial dislocations in GaAs

TL;DR

This study evaluates the effectiveness of molecular statics simulations with a Tersoff potential in modeling partial dislocation cores in GaAs, comparing results with density functional theory to assess accuracy.

Contribution

It demonstrates that molecular statics can reliably model Ga-terminated dislocation cores, but shows limitations for As-terminated cases, highlighting the method's applicability scope.

Findings

Bond lengths in Ga-terminated cores agree within 5-10% with DFT results.

Significant discrepancies found in As-terminated dislocation core modeling.

Molecular statics is suitable for certain dislocation structures in GaAs.

Abstract

The suitability of molecular statics (MS) simulations to model the structure of 90{\deg} glide set partial dislocation cores in GaAs is analyzed. In the MS simulations the atomic positions are iteratively relaxed by energy minimization, for which a Tersoff potential parametrization appropriate for nanostructures has been used. We show that for the Ga terminated partial the resulting bond lengths of the atoms in the dislocation core agree within 5-10% with those of previous density functional theory studies, whereas a significant discrepancy appears in the case of the As terminated partial.