Self-organized Gd atomic superlattice on Ag(111): Scanning tunneling microscopy and kinetic Monte Carlo simulations

With scanning tunneling microscopy, we experimentally demonstrate the self-organized Gd atomic superlattice on Ag(111) surface at low temperature. The diffusion barrier of a single Gd adatom and the long-range interaction between Gd adatoms on Ag(111) are determined. With these parameters, the formation mechanism is discussed and we confirm the validity of the previous discussed preconditions for formation of a good superlattice. The well-ordered structure is reproduced by the kinetic Monte Carlo simulations with the experimentally determined parameters. As well-ordered superlattice is realized in two different lanthanide adatoms on Ag(111), we predict that similar self-organization could form in other lanthanide adatoms because of their identical electron configuration in the outer shell and similar atomic radii.