Modeling lattice expansion and cohesive energy of nanostructured materials

The lattice constants and cohesive energies of nanostructured materials (NSs) are modeled using a hard-sphere approach and the model for size-dependent interface energy. The lattice constant of NSs will expand opposite to that of nanoparticles (NPs) as the grain size of NSs and the diameter of NPs decrease. Associated with it, the cohesive energies increase in both cases. However, the increment is less obvious for NSs because the bond deficit at grain boundaries is smaller than that at surfaces. The predictions agree fairly well with the available experimental or computer simulation results of nanostructured metals and semiconductors.