Surface diffusion in the framework of lattice gas model: mean field treatment and Monte-Carlo method

We have studied the lattice gas model subject to nearest neighbour repulsive interactions with the Monte-Carlo method leading to a clear understanding of order-disorder transition and its effect on the adsorption and intercalation processes. The lattice division into two (three) sublattices in the case of the square (triangular) lattice enables us to underline the appearance and the growth of the ordered phase. A comparison between the mean field approximation and Monte-Carlo results is also presented.We have studied the lattice gas model subject to nearest neighbour repulsive interactions with the Monte-Carlo method leading to a clear understanding of order-disorder transition and its effect on the adsorption and intercalation processes. The lattice division into two (three) sublattices in the case of the square (triangular) lattice enables us to underline the appearance and the growth of the ordered phase. A comparison between the mean field approximation and Monte-Carlo results is also presented

Ionic diffusion on a lattice: Effects of the order-disorder transition on the dynamics of non-equilibrium systems

We examine the behaviour of the concentration profiles of particles with repulsive interactions diffusing on a host lattice. At low temperature, the diffusion process is strongly influenced by the presence of ordered domains. We use mean field equations and Monte-Carlo simulations to describe the various effects which influence the kinetic behaviour. An effective diffusion coefficient is determined analytically and is compared with the simulations. Finite gradient effects on the ordered domains and on the diffusion are discussed. The kinetics studied is relevant for superionic conductors, for intercalation and also for the diffusion of particles adsorbed on a substrate