A molecular dynamics analysis of the mechanical effect of water on the deformation ofsilicon monocrystals subjected to nano-indentation

Abstract

This paper discusses the mechanical effect of water on the deformation of siliconmonocrystals under nano-indentation with the aid of molecular dynamics analysis. Therigid TIP4P model was used to simulate the interactions between water molecules while thelong-ranged non-bonded Lennard-Jones potential was applied for the pairs of unlikemolecules. It was found that upon loading water molecules are lodged into the cavities ofthe silicon substrate, causing subsurface damage. The diamond cubic structure in theindentation zone transforms into an amorphous state with a body-centred tetragonal form(β-silicon) below the indentor. The presence of water significantly reduces the indentor–siliconadhesion that alters the structure of the residual deformation zone after completeunloading.