Grain size dependence of the bulk modulus of nanocrystalline nickel

The grain size dependence of the bulk modulus of nanocrystalline nickel is investigated by means of molecular dynamics simulations. The calculated data show an increasing compressibility with decreasing grain size and can be modeled by a rule of mixture. The average grain boundary width as well as the critical grain size for structural stability are determined. Moreover, we identify differences in the structural and elastic properties of the bulk amorphous phase and the grain boundary phase.