Atomistic simulation of modulus deficit in an aggregate of metal spheres

Abstract

This paper reports molecular-dynamics modeling of the elastic behavior of a self-assembled aggregate of perfect face-centered-cubic crystal spheres, a morphology suggested by recent experimental observations on thin-film copper electrodeposits. Results of molecular-dynamics calculations on the elastic behavior of nanorods, chains of nanospheres, and self-assembled arrays of nanospheres are presented; an embedded-atom model potential incorporating substantial elastic anisotropy was used. The variety of geometries modeled helped to distinguish between effects of elastic anisotropy and effects of morphology. The results show that a self-assembled aggregate of spheres has a Young’s modulus tens of percent lower than bulk material, while its density is only a few percent below bulk.