Comparing empirical interatomic potentials to modeling silicon surface stress

TY - JOUR

T1 - Comparing empirical interatomic potentials to modeling silicon surface stress

AU - Esfahani, Mohammad Nasr

N1 - Publisher Copyright: © 2022 Elsevier Ltd

PY - 2022/3/1

Y1 - 2022/3/1

N2 - This study compares six widely used classical many-body potentials – Tersoff-T3, Stillinger–Weber, modified Tersoff, optimized modified Tersoff, environment-dependent interatomic potential and modified embedded atom method – to model silicon surface stress. Functional forms for all potentials are first analyzed to determine atomic stress. This is then followed by a set of surface stress analysis on silicon {100} and {110} surfaces. A significant difference between those potentials is observed to calculate the surface stress in silicon crystal. The Tersoff-T3 and environment-dependent interatomic potentials demonstrate a significant surface stress in unreconstructed silicon {100} and {110} surfaces, while the Stillinger–Weber potential estimates a negligible surface stress. The implication of the surface stress is studied on the mechanical response of silicon nanowires. A dramatic contrast between potentials is recognized to calculate the equilibrium elongation due to the surface stress in silicon nanowires along <100> crystal orientation. While the environment-dependent interatomic potential predicts a contraction in the equilibrium elongation in relaxed nanowires, the Tersoff-T3 potential exhibits a considerable uniaxial expansion in silicon nanowires comparable with density functional theories. Findings in this work give more insight into the capability of empirical interatomic potentials to capture the surface stress in silicon nanostructures.

AB - This study compares six widely used classical many-body potentials – Tersoff-T3, Stillinger–Weber, modified Tersoff, optimized modified Tersoff, environment-dependent interatomic potential and modified embedded atom method – to model silicon surface stress. Functional forms for all potentials are first analyzed to determine atomic stress. This is then followed by a set of surface stress analysis on silicon {100} and {110} surfaces. A significant difference between those potentials is observed to calculate the surface stress in silicon crystal. The Tersoff-T3 and environment-dependent interatomic potentials demonstrate a significant surface stress in unreconstructed silicon {100} and {110} surfaces, while the Stillinger–Weber potential estimates a negligible surface stress. The implication of the surface stress is studied on the mechanical response of silicon nanowires. A dramatic contrast between potentials is recognized to calculate the equilibrium elongation due to the surface stress in silicon nanowires along <100> crystal orientation. While the environment-dependent interatomic potential predicts a contraction in the equilibrium elongation in relaxed nanowires, the Tersoff-T3 potential exhibits a considerable uniaxial expansion in silicon nanowires comparable with density functional theories. Findings in this work give more insight into the capability of empirical interatomic potentials to capture the surface stress in silicon nanostructures.

KW - Atomic simulations

KW - Interatomic potential

KW - Mechanical behavior

KW - Silicon crystal

KW - Surface stress

UR - http://www.scopus.com/inward/record.url?scp=85123051484&partnerID=8YFLogxK

U2 - 10.1016/j.ssc.2022.114656

DO - 10.1016/j.ssc.2022.114656

M3 - Article

AN - SCOPUS:85123051484

SN - 0038-1098

VL - 344

JO - Solid state communications

JF - Solid state communications

M1 - 114656

ER -