Molecular Dynamics Simulation of GaN Nano-grinding

Abstract

The molecular dynamics model of wurtzite crystal structure GaN in nano-grinding was established using the Tersoff multi-body potential. The complete structure defect-free GaN model and the defect-containing GaN model were set for comparison. The MD model used hemispherical diamond abrasive grains as the grinding tool, and the micro-regular ensemble (NVE) was used in the grinding process. Additionally, the GaN grinding simulation results under different loading conditions (changing grinding speed, depth) were analyzed to study the changes of internal crystal structure and the evolution of crystal defects. The results show that there is a transition from wurtzite to zinc-blende in GaN during the grinding. Moreover, defects and grinding force increase as the depth of grinding increases. The grinding speed has no obvious influence on the grinding force. When the grinding distance reaches 15 nm, the grinding force decreases slightly with the increase of the speed.