SURFACE-ENERGY TRANSFER BY LOW-ENERGY POLYATOMIC ION COLLISIONS

Experiments and classical dynamics simulations are performed to determ ine the energy transferred when C4H4S+, Si(CD3)(3)(+), and Fe(C5H5)(2) (+) collide with clean Au(lll), hexanethiolate/Au(111) and various org anic multilayer surfaces. For these various ion-surface pairs, the ene rgy transferred to the surface E-surf can be described by a linear fun ction of the incident energy E over the range E = 10-70 eV. For the he xanethiolate and organic multilayer surfaces, the slope of this line v aries from 0.65 to 0.94 and indicates an efficient transfer of energy to the surface. For the clean Au(lll) surface, E-surf is much smaller with slopes of 0.15 and 0.43. Classical dynamics simulations quantitat ively duplicate the E-surf behavior for Si(CD3)(3)(+) scattering off h exanethiolate and find that E-surf varies roughly with Ecos(0.8)(theta (i)), where theta(i) is the incident ion angle.