Atomistic Study of Twinning in Gold Nanowhiskers

Abstract

Twinning can become an important deformation mechanism in fcc metals once the crystal size is reduced to the sub-micron scale, e.g., in nanocrystals or nanowhiskers. The study of the twinning process, the interactions between propagating twins and between dislocations and twins is therefore important for a better understanding of the mechanical properties of metallic nanostructures. Here we show the results of atomistic simulations of defect-free nanowhiskers under tensile load using different EAM potentials for Au. The mechanisms of twin propagation and twin-stacking fault interaction are described and a modification to the criterion by Chen et al. [M. Chen et al., Science 300, 1275, 2003] for predicting twinning and its size dependence is presented.