Adsorption of Li (K) on the Si(001)-(2×1) surface: Scanning-tunneling-microscopy study

Abstract
Li and K adsorption on the Si(001)-(2×1) surface have been investigated by use of scanning tunneling microscopy (STM). We found that, at the initial stage of adsorption, Li (K) atoms (1) adsorb on top of one of the dimer-forming Si atoms to form covalentlike directional bonds with Si atoms and tend to stabilize asymmetric (buckled) dimerization, and (2) form linear chains, perpendicular to the substrate dimer rows. Our STM results are significantly different from the conclusions of earlier reports.