Probing surface and edge energies of gold using high-symmetry nanoparticles

The equilibrium shape of metal particles is the polyhedron that minimizes the total surface energy. Such shapes are routinely modeled using variations of the Wulff construction [1]. At the nanoscale, edge energy becomes important as the fraction of atoms at edges of nanoparticles cannot be neglected. We present a systematic method for calculation of edge energies based on atomistic simulations of high-symmetry nanoparticles. We derive an expression for the total energy of the nanoparticle that includes contributions from bulk, surface and edge atoms. We use this expression to fit the energy of nanoparticles as a function of the number of atoms and derive bulk-, surface- and edge energies. We repeat this procedure for different nanoparticle shapes. For the calculation of total energy, we employ a variety of interatomic potentials and first-principles Density-Functional-Theory (DFT) calculations. Finally, we discuss electronic properties of these nanoparticles in comparison to continuum models [2].

[1] G. D. Barmparis, Z. Lodziana, N. Lopez and I. N. Remediakis, Beilstein J. Nanotechn. 6, 361, (2015)
[2] G. D. Barmparis, G. Kopidakis, and I. N. Remediakis, Materials, 9, 300 (2016).