Ion impact desorption of monolayer adsorbates on solid surfaces

The paper describes an application of the ion impact desorption of monolaye r adsorbates on solid surfaces to determine their binding energies and to i nvestigate their dynamic behavior under ion irradiation. The combination of the projectile, adsorbate and substrate masses is discussed for determinat ion of the cross-sections for recoil implantation and desorption, which pro vide the potential barrier heights for the inward and outward recoils, resp ectively. The experimental decay curves of the coverages of single adsorbat es and binary adsorbates of noble metals on the Si(111) surface during 5 ke V Ar+ bombardment, measured by RES and AES technique, are presented, from w hich the cross-sections and the corresponding potential barrier heights hav e been determined. From comparison between the potential barrier heights an d the activation energies for thermal desorption. the binding energy has be en determined and the layered structure of adsorbates is discussed. Interac tion with radiation defects has been analyzed. An experimental energy distr ibution of neutral adsorbates desorbed, which provides the: binding energy in the absense of radiation induced defects, is presented and discussed.