The influence of a nanocrystal size on the results of molecular-dynamics modeling

In connection with the rapid progress in nanotechnology, a need has presently arisen in obtaining nanostructures with desirable properties by processes using various thermomechanical actions exerted on starting structures. Previously, we performed a molecular-dynamics study of the mechanical failure of a three-dimensional defect-free copper nanocrystal under uniaxial tension. Based on the mesoanalysis, such mechanical characteristics of the nanocrystal were obtained as the stress vs strain relation and the Young modulus. Local criteria of dynamical fracture have been established. In the present work, data concerning the effect of nanocrystal size on atomistically modeled characteristics of copper nanocrystals are reported. A certain critical size of six crystal cells has been found in a copper nanocrystal. The nanostructure sizes being over this value, the calculated characteristics do not depend on nanocrystal size.