Atom–surface scattering dynamics at hyperthermal energies

We report molecular beam scattering of hyperthermal Xe atoms over an energy range 1<Ei(eV)<10 from single crystal surfaces of GaAs(110), Ag(100), and Ge(100). The angular distributions from the corrugated surfaces show sharp backscattered rainbow maxima related to the topography of the crystal surface. In contrast the smooth surfaces yield quasispecular lobes suggestive of structure scattering. The large energy loss for all surfaces scales on average with the energy of local normal motion. A simple binary interaction model is developed which accounts for many of the phenomena observed from corrugated surfaces. With the aid of a comparison classical trajectory study, these results provide some understanding of the mechanism by and extent to which a solid can dissipate the energy of a hyperthermal collision.