Atomistic elucidation of the effect of surface roughness on curvature-dependent surface energy, surface stress, and elasticity

It is well known that surface energy and the associated properties such as surface stress and surface elasticity have a significant effect on the physical behavior of nanostructures. In this letter, using a combination of atomistic simulations and a simple continuum model, we elucidate the role of surface roughness on the renormalization of surface stress, surface elastic constants, as well as the (generally ignored) term that represents the curvature dependence of surface energy (crystalline Tolman's length). We find, consistent with a recent theoretical prediction and in sharp contrast to few others, that the surface stress is negligibly impacted by roughness. However, even moderate roughness is seen to dramatically alter the surface elasticity modulus as well as the crystalline Tolman's length. We illustrate a simple application on the impact of roughness on nanosensors. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3695069]