Structural and electronic reconstructions in adsorbed layer

Abstract

Abstract The influence of electron-phonon interaction on structural and electronic reconstructions of the ground state is considered for the system of adsorbed atoms on the metal surface. The consideration of this interaction is shown to result in a qualitative change of the reconstructions character with the doubling of the period of the two-dimensional lattice of adsorbed atoms (adatoms) at sufficiently strong electron-phonon interaction. These transitions are accompanied by both hop-like and smooth change of the effective charge of adatoms and their equilibrium positions; yhey can occur even at arbitrary weak interaction between adatoms. The structure with the doubled period is also shown to be unstable with respect to the formation of a long-wave superstructure, incommensurable with the lattice period of adatoms. The applicability of the model is discussed for the explanation of experimentally observed transitions on clean surfaces of transition metals.