Driving forces for Ag-induced periodic faceting of vicinal Cu(111)

Abstract

Adsorption of submonolayer amounts of Ag on vicinal Cu(1 1 1) induces periodic faceting. The equilibrium structure is characterized by Ag-covered facets that alternate with clean Cu stripes. In the atomic scale, the driving force is the matching of Ag(1 1 1)-like packed rows with Cu(1 1 1) terraces underneath. This determines the preference for the facet orientation and the evolution of different phases as a function of coverage. Both Cu and Ag stripe widths can be varied smoothly in the 3–30 nm range by tuning Ag coverage, allowing to test theoretical predictions of elastic theories.