Effect of oxygen adsorption on the energy losses in grazing scattering of hydrogen ions on Ag(1 1 0)

In this work we present a study of the effect of oxygen adsorption on the energy loss of 4 keV hydrogen ions, which are scattered off an Ag (1 1 0) single-crystal surface with varying coverages of oxygen. In this case oxygen adsorption leads to an added row reconstruction of the surface. We performed measurements for grazing angles as a function of crystal azimuthal orientation, which show large differences in energy losses. Experimental results are discussed in the light of trajectory calculations of protons scattered under grazing incidence conditions on the surface. Using non-linear models for stopping power, ab initio crystal structure calculations of the electronic density and semi-classical simulations, we obtain data that is in very good agreement with experimental results. These simulations in particular allow us to properly take into account the variations of the surface electronic density and hence obtain an accurate description of the energy loss processes for ion scattering along various azimuthal orientations of the target.