Term information
Model that mathematically describes features of surface diffusion. "Surface diffusion is a general process involving the motion of adatoms, molecules, and atomic clusters (adparticles) at solid material surfaces.[1] The process can generally be thought of in terms of particles jumping between adjacent adsorption sites on a surface, as in figure 1. Just as in bulk diffusion, this motion is typically a thermally promoted process with rates increasing with increasing temperature. Many systems display diffusion behavior that deviates from the conventional model of nearest-neighbor jumps.[2] Tunneling diffusion is a particularly interesting example of an unconventional mechanism wherein hydrogen has been shown to diffuse on clean metal surfaces via the quantum tunneling effect." source: http://en.wikipedia.org/wiki/Surface_diffusion [1] Oura, Lifshits, Saranin, Zotov, and Katayama 2003, p. 325 [2] Antczak, Ehrlich 2007, p.39