THEORETICAL-STUDY OF THE DIFFUSION OF ALKALI-METALS ON A CU(111) SURFACE

We present a theoretical study of the diffusion of Li, Na and K on a C u(lll) surface. Various diffusional paths are identified and character ized in terms of kinetic parameters such as diffusion constants and ac tivation energies. We use a model potential parametrized from DFT calc ulations to determine adsorption energies, surface corrugation and dif fusional behaviors. Two representations of the copper surface (2D and 3D) are used to investigate its effect on the adsorption patterns, dif fusion constants and activation energies. An interesting result is tha t the adsorption pattern for Na and K changes when adding layers of su bstrate (2D --> 3D) favouring unusual adsorption sites, which is in ag reement with recent theoretical evidence.