Long-time scale molecular dynamics study of Co diffusion on the Au(1 1 1) surface

A long-time scale molecular dynamics simulation of a Co adatom on an unreconstructed Au(1 1 1) surface is performed from 140 to 870 K. Co and Au are modelized by many-body potentials determined within the second-moment approximation of the tight-binding theory. From 260 to 750 K, the diffusion exhibits an Arrhenius behavior with a migration energy of Em=0.160 eV and a pre-exponential factor of D0=5.8×10−4 cm2/s. From 810 K, an exchange process of the Co adatom with a surface gold atom of surface is observed.