The role of electron–hole pair excitations in desorption dynamics

Publisher Website
Google Scholar
Abstract
We carry out model calculations to compare the role of phononexcitations and electron‐hole pair excitations in thermal desorption from metals. Phonon effects are computed by using a model developed previously [J. Chem. Phys. 7 9, 2436 (1983)]. The rate of energy transfer from the adsorbate to electrons (caused by Coulomb coupling to the effective charge of the adsorbate) is computed within the Random Phase Approximation. Our main result is that the effect of electron‐hole pair excitations on the rate of desorption is negligible, except for the few cases in which the vibrational frequency of the chemisorption bond is many times (i.e., five to ten times) larger than the surface Debye frequency.