Bimodal energy distributions in the scattering of Ar+ ions from modified surfaces at hyperthermal energies

Collisions of Ar+ ions with three different surfaces have been studied by mass and energy resolved ion-scattering spectrometry. Kinetic energy distributions of scattered ions measured as a function of ion energy and scattering angle show two energetically and spatially distinct peaks corresponding to a low energy loss process and a very high energy loss process. The low energy loss peak is interpreted as due to the interaction of the Ar+ ions with the self-assembled monolayer surface acting as a bulk surface.