Numerical Study Of The Stability Of (111) And (331) Microfacets On Au, Pt, And Ir (110) Surfaces

By means of kinetic Monte Carlo simulations of a growth model with realistic barriers for surface diffusion, the stability of (111) and (331) facets on Au, Pt, and Ir(110) is investigated through the thermal relaxation of some epitaxially grown samples. The results obtained on the metastable step formation energy and the relative stability among facets are consistent with experimental observations. We show that the leapfrog diffusion mechanism recently discovered on Au(110) and Pt(110) occurs also on Ir(110) and represents the essential ingredient which provides the microscopic driving force for microfacet stability on these noble metals.