Department of Mechanical, Aerospace and Nuclear Engineering,
Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| This paper presents physics based design of nanorods, and mechanical deformation of such nanorods. Our study relies on primarily atomistic simulations, and the final results are corroborated by accompanying experiments. The design starts from understanding of three pieces of fundamental physics: geometrical shadowing during physical vapor deposition, twin formation during growth, and three-dimensional Ehrlich-Schwoebel barriers. The integration of these three pieces leads to the design of selforganized branching of nanorods. Due to large surface-to-volume ratio, both elastic and plastic deformations of nanorods or nanoplates are distinctive from their bulk crystals. Our atomistic simulations show that Young's moduli of nanoplates can be larger or smaller than their bulk counterparts. The variation is a result of competition among bonds loss and bond saturation at surfaces, and bulk nonlinear elasticity. Further, at nanoscale, anomaly of dislocation glide is possible. |
full paper (pdf, 288 Kb)