Breakdown of normal energy scaling at high impact energy for O2 on Ag(001)

We reinvestigated non-dissociative chemisorption of O-2 on Ag(001) by the King and Wells reflectivity method and high-resolution electron energy loss spectroscopy over a wide range of impact energies of O-2. In analogy to O-2/Ag(110), we find that the sticking probability has a maximum at a total energy of 0.7 eV corresponding to the onset of direct inelastic scattering from the repulsive part of the chemisorption potential. Below it, normal energy scaling is approximately obeyed, whereas above it, a breakdown of such behaviour is observed. The decrease in sticking probability at high impact energy is more pronounced for O-2/Ag(001) than for O-2/Ag(110).

We reinvestigated non-dissociative chemisorption of O2 on Ag(001) by the King and Wells reflectivity method and high-resolution electron energy loss spectroscopy over a wide range of impact energies of O2. In analogy to O2/Ag(110), we find that the sticking probability has a maximum at a total energy of 0.7 eV corresponding to the onset of direct inelastic scattering from the repulsive part of the chemisorption potential. Below it, normal energy scaling is approximately obeyed, whereas above it, a breakdown of such behaviour is observed. The decrease in sticking probability at high impact energy is more pronounced for O2/Ag(001) than for O2/Ag(110). © 1998 Elsevier Science B.V. All rights reserved.