First-principles calculations were made of the adsorption and clustering energetics, and diffusion and kinetic barriers for a large selection of possible systems and motions involving Cu vacancies and adatoms, In adsorbates, as well as clusters and complexes thereof. Possible modes of vacancy creation and In incorporation were considered, involving kink sites at steps, as well as the interlayer diffusion of Cu with and without In at the step edge. Among the results shedding light on the diffusion mode of In:Cu(100) as well as on the surfactant action of In, it was found that In diffused via concerted motion with vacancies, and that In at a step drastically lowered the exchange down-step diffusion barrier for Cu, thus favouring two-dimensional growth.

Indium on Cu(100) from First Principles: Energetics, Complex Formation, and Diffusion of Adsorbates and Vacancies on Terraces and at Steps. G.Colizzi, G.Biddau, V.Fiorentini: Physical Review B, 2009, 79[16], 165441