Surface energy and work function of elemental metals

TLDR

The study explains the trend in surface energies across alkali, alkaline earth, rare‑earth, transition, and noble metals, linking them to liquid‑metal surface tension. The authors used a Green’s‑function linear‑muffin‑tin‑orbital approach within tight‑binding and atomic‑sphere approximations to compute surface energies and work functions for six close‑packed surfaces of 40 elemental metals. The calculated surface energies and work functions agree with full‑potential calculations and experimental data within 15%, explain the smooth polycrystalline work‑function trend, and demonstrate that modern ab initio methods are at least as accurate as experimental measurements.

Abstract

We have performed an ab initio study of the surface energy and the work function for six close-packed surfaces of 40 elemental metals by means of a Green's-function technique, based on the linear-muffin-tin-orbitals method within the tight-binding and atomic-sphere approximations. The results are in excellent agreement with a recent full-potential, all-electron, slab-supercell calculation of surface energies and work functions for the 4d metals. The present calculations explain the trend exhibited by the surface energies of the alkali, alkaline earth, divalent rare-earth, 3d, 4d, and 5d transition and noble metals, as derived from the surface tension of liquid metals. In addition, they give work functions which agree with the limited experimental data obtained from single crystals to within 15%, and explain the smooth behavior of the experimental work functions of polycrystalline samples as a function of atomic number. It is argued that the surface energies and work functions calculated by present day ab initio methods are at least as accurate as the experimental values.