Surface energy transfer by low energy polyatomic ion collisions

Experiments and classical dynamics simulations are performed to determine the energy transferred when C₄H₄S⁺, Si(CD₃)⁺₃, and Fe(C₅H₅)⁺₂ collide with clean Au(111), hexanethiolate/Au(111) and various organic multilayer surfaces. For these various ion-surface pairs, the energy transferred to the surface E_surf can be described by a linear function of the incident energy E over the range E = 10-70 eV. For the hexanethiolate and organic multilayer surfaces, the slope of this line varies from 0.65 to 0.94 and indicates an efficient transfer of energy to the surface. For the clean Au(111) surface, E_surf is much smaller with slopes of 0.15 and 0.43. Classical dynamics simulations quantitatively duplicate the E_surf behavior for Si(CD₃)⁺₃ scattering off hexanethiolate and find that E_surf varies roughly with E cos^0.8(θ_i), where θ_i is the incident ion angle.