1203.2896 (L. Martin-Gondre et al.)

Competition between electron and phonon excitations in the scattering of
nitrogen atoms and molecules off tungsten and silver surfaces    [PDF]

L. Martin-Gondre, M. Alducin, G. A. Bocan, R. Díez Muiño, J. I. Juaristi

We investigate the role played by electron-hole pair and phonon excitations in the interaction of reactive gas molecules and atoms with metal surfaces. We present a theoretical framework that allows us to evaluate within a full-dimensional dynamics the combined contribution of both excitation mechanisms while the gas particle-surface interaction is described by an ab-initio potential energy surface. The model is applied to study energy dissipation in the scattering of N$_2$ on W(110) and N on Ag(111). Our results show that phonon excitation is the dominant energy loss channel whereas electron-hole pair excitations represent a minor contribution. We substantiate that, even when the energy dissipated is quantitatively significant, important aspects of the scattering dynamics are well captured by the adiabatic approximation.

View original: http://arxiv.org/abs/1203.2896