Ag adatom and dimer motion on Cu(1 1 0)(1 x 2) missing row surface

The diffusion of Ag monomer and dimer on Cu(1 1 0)(1 x 2) missing row reconstructed surface is investigated by using the molecular dynamics simulation based on semi-empirical many-body potentials derived from the embedded atom method. In the case of monomer diffusion, both simple jump and long jump follow an Arrhenius law in a large temperature range (300-500 K) but with a small difference in activation energy. The activation barrier energy for simple jump is found to be (0.27 +/- 0.02) eV with corresponding prefactor 5.9 ps(-1). However, for double jump we found E-a2 = (0.33 +/- 0.05) eV. While in the case of dimer, we found that the adatoms activity is notably reduced at low temperature (T < 400 K) and the diffusion via dissociation-reassociation process is more favoured than the other processes. This finding is in a good agreement with the energetic prediction. The presence of concerted jump and leapfrog process is very rare due to their high corresponding activation energy. (C) 2013 Elsevier B.V. All rights reserved.