Reconstruction-Induced Surface Faceting: The Contrasting Behaviour of Au(111) and Pb(111)

We study the morphology of vicinal surfaces close to the reconstructing Au(111) and the nonreconstructing Pb(111) face. Molecular-dynamics simulations with many-body potentials for gold and lead have been conducted, using (534) as a test vicinal at T ∼ 0.8 T m , where T m is the bulk melting temperature. It is found that, as a result of surface reconstruction, the gold vicinal surface undergoes faceting, while in lead the vicinal surface remains stable. Our results explain the origin of sharp edges on the equilibrium crystal shape of gold and smooth edges on lead.