Local Variations in the Temperature of the Growing Layer at Condensation from Gaseous Phase

Abstract

The influence of surface heat conductivity on the process of adsorbate islands formation during condensation from the gaseous phase is studied in the framework of numerical simulations. We generalize the standard reaction-diffusion model for the spatio-temporal evolution of he adsorbate concentration on the growing layer by taking into account the non-equilibrium chemical reactions responsible for the adatoms motion between neighbour layers or stable dimers formation. We assume, that the surface temperature can be locally changed during adsorption/desorption processes. Within the framework of the linear stability analysis of the stationary homogeneous state to spatial perturbations we compute the phase diagram illustrating the possibility of pattern formation in the system. By using numerical simulation it has been shown that thermal conductivity affects the transition processes of adsorbate structures formation. It has been established that the average size of adsorbate islands increases with time according to the power law, and the growth exponent increases with the thermal conductivity. It was found that an increase in the thermal conductivity of the surface leads to a transformation of the distribution of adsorbate islands from from the Log-normal to Gaussian. It is shown that the mean linear size of stationary adsorbate structures is characterized by a nanometer scale.