Melting and nonmelting behavior of the Au(111) surface

A molecular-dynamics study of the melting behavior of Au(111) (both reconstructed and unreconstructed) has been carried out using a recently developed many-body force scheme. The reconstructed (denser) surface remains stable up to the bulk melting temperature $T_M$, showing no form of microscopic surface melting. By contrast, the two outermost layers of the unreconstructed surface "melt" ∼100 K below $T_M$. However, no more layers melt as $T_M$ is approached. The nonmelting of Au(111) is contrasted with the gradual melting behavior of Lennard-Jones surfaces.