The influence of adatom diffusion on coverage and emission current fluctuations

In the present work, we have studied the influence of lateral interactions between adatoms (atoms adsorbed on a lattice-gas surface) on their surface mobility. In addition, we have investigated fluctuations of the adatom surf ace coverage and of the corresponding emission current. For this purpose, w e have used the real space renormalization group (RSRG) method and the Mont e Carlo (MC) simulation technique. We have evaluated the coverage and tempe rature dependences of the tracer, jump, and chemical diffusion coefficients , of the MSCFs and of the spectral density of emission current fluctuations . It is shown that lateral interactions between adatoms drastically change the behavior of these kinetic quantities especially at low temperatures whe n the system undergoes first (for attractive) or second (for repulsive ad-a d interactions). The agreement between RSRG and MC data is surprisingly goo d despite the fact that both methods constitute very different approaches. (C) 2000 Elsevier Science Ltd. All rights reserved.