Atomistic simulations of spherical indentations in nanocrystalline gold

Atomistic simulations are employed to investigate the nanoindentation deformation properties of model nc-Au with grain diameters of 5 and 12 nm, using both conjugant gradient and molecular dynamics. It is found that grain boundaries act as efficient sinks for dislocation nucleation below the indenter and that intergranular sliding occurs. Further, we establish that at the 5-nm grain diameter regime there is a decrease in the Young's modulus.