Bulk mediated surface diffusion: the infinite system case

J. A. REVELLI, C.E. BUDDE, D. PRATTO AND H.S. WIO

EUROPEAN PHYSICAL JOURNAL B - CONDENSED MATTER

EDP Sciences, Societá Italiana di Fisica, Springer-Verlag.

Año: 2003 vol. 36 p. 245 - 251

1434-6028

An analytical soluble model based on a Continuous Time Random Walk (CTRW) scheme for the adsorption-desorption processes at interfaces, called bulk-mediated surface diffusion is presented. The time evolution of the effective probability distribution width on the surface is calculated and analyzed within an anomalous diffusion framework. The asymptotic behavior for large times shows a sub-diffusive regime for the effective surface diffusion but, depending on the observed range of time, other regimes may be obtained. Monte Carlo simulations show an excellent agreement with the analytical results. As an important byproduct of the indicated approach, we present the evaluation of the time for the first visit to the surface.