Role of interatomic potentials in molecular dynamics simulations of silicon nanomachining

Abstract

This investigation examines the impact of diverse interatomic potentials on the molecular dynamics simulation results of deformation and microstructural evolution during nanomachining. The results revealed that the application of the Stillinger-Weber (SW) potential led to the occurrence of significant stacking faults and dislocations. Conversely, the Tersoff potential prevented the initiation of dislocations during the loading segment. The Tersoff potential adept representation of the high-pressure phase transformation of monocrystalline silicon throughout the nanoindentation more accurately predicted mechanical parameters when compared with experimental data. Analytical bond-order potential (ABOP) accurately delineated the deformation mechanisms, including dislocation nucleation and amorphization, during nanoscratching. In contrast, the SW potential tended to underestimate the generation of high-pressure phases, with dislocation nucleation predicted by the SW potential dominating the plastic deformation of monocrystalline Si, contradicting the experimental observations. Consequently, this study concludes that the Tersoff potential and ABOP are the preferred choices for investigating the behavior of monocrystalline Si under nanomachining conditions.