The diffusion coefficient of the O/W(110) system at low temperatures, below critical point, exhibited some interesting properties. It was observed that the activation energy of the diffusion process increased rapidly at the phase transition from disordered to the ordered (2x1) phase. It was possible to model this rapid change in the activation energy, by a proper choice of the transition probabilities in the lattice gas model. This rapid increase of the activation energy was visible as the change of the scaling of the diffusion curves. The same transition rates were used to calculate the diffusion coefficient at higher densities from 0.5 to 1. Scaling function showed how the activation energy varied with density. The density dependence of the activation energy changed its character on coming from lower to higher temperatures, what could be related to the changes in the phase diagram.

Collective Diffusion of O/W(110) at High Coverages: Monte Carlo Simulations. M.A.Załuska-Kotur, A.Łusakowski, S.Krukowski, L.A.Turski: Surface Science, 2004, 566-568[1-3], 210-5