Influence of Surface Effects on the Elastic Properties of Silicon Nanowires with Different Cross Sections

Based on the anharmonic Keating model and the modified bending theory, an analytical semi-continuum atomistic lattice model is proposed for the size-dependent bending mechanical analysis of silicon nanowires (SiNWs) with different cross-sectional shapes. The semi-continuum model proves that the elastic behavior of SiNWs is size-dependent and predicts softer or stiffer SiNWs which depend on the relaxation coefficient and the surface tension. It also shows that the size effects of the mechanical responses of SiNWs depend on not only surface effects but also the cross-sectional shapes of SiNWs.