InGaAs/GaAs nanotubes simulation: Comparison between continual and molecular dynamics approaches

The results of InGaAs/GaAs nanotubes synthesis on atomic scale using molecular dynamics are presented. On basis of the comparison with mechanics of continua it is shown that the values of nanotubes radius obtained by molecular dynamics calculations are less then elasticity theory predicts with the discrepancy exceeding 30% for a few monolayer thick heterostructure. The influence of discreteness of matter and surface energy to this discrepancy was considered. The proposed simple discrete model produces estimation of the correction to elasticity theory formula due to the discreteness of matter. Though this correction also predicts decrease for equilibrium heterostructure radius of curvature, its value is not sufficient for the explanation of molecular dynamics results. Comparison of the potential energy distribution with elasticity theory predictions shows the importance of heterostructure surface layers contribution to this discrepancy. Introduction of surface energy to the elasticity theory model expands the limits of continuum mechanics application for nanoscale simulations. (c) 2005 Published by Elsevier B.V.