Effect of Loading Rate on Monocrystalline Germanium Nanoindentation Behavior Based on Molecular Dynamics

Monocrystalline germanium (Ge) is a crucial precision optics and semiconductor material, whose mechanical properties determine the performance and life of parts. In this paper, we simulated nanoindentation of monocrystalline Ge with different loading rates through molecular dynamics and analyzed the force, deformation, temperature, and energy of simulation results. We showed that overall force shows a downward trend at high loading rate; the thickness of the deformation layer is not affected by loading rate, but a high loading rate will expand the deformation layer in horizontal direction; high temperature increases the distance between atoms and changes lattice structure, but atoms will stack into a form with higher space utilization; kinetic energy changes are concentrated in the deformed layer. These results provide some theoretical support for study of mechanical properties of monocrystalline Ge.