FIRST PRINCIPLES CALCULATIONS OF ADSORPTION AND DIFFUSION OF Ba ON A RECONSTRUCTED Si(001) SURFACE

Adsorption and diffusion of a Ba adatom on a reconstructed Si(001) surface were studied using first principles density functional calculation. It was found that the lowest energetic configuration is that the Ba atom resides at the T3' (which is displaced along the $[\bar{1}10]$ direction from the T3 site by ~ 0.26 Å). An anisotropic diffusivity of Ba on the reconstructed surface was found. The preferred direction of diffusion was the trough between Si dimer rows.