Corrugation Effects in Oxygen Surface Trapping at Hyperthermal Energies

We have measured trapping probabilities for 5--600 eV O⁺ ions incident on Cu(001) at 45^∘ and along the sample normal. These results have been reproduced using classical trajectory simulations. In the simulations, the surface trapping probability PS is distinguished from the total trapping probability PT. At 45^∘{}, the energy dependence of PS differs significantly from that of Na⁺ incident on Cu(001). Trajectory analysis shows that differences between the trapping trends can be attributed to differences in the apparent surface corrugation for these two systems.