Classical-trajectory studies of electron- or photon-stimulated desorption from ionic solids

Abstract

We present trajectory calculations of electron- or photon-stimulated desorption of positive ions from alkali halides via the ‘‘Coulomb explosion’’ mechanism, in which desorption is due to the repulsive forces resulting from formation of a positive halogen ion (${\mathrm{F}}^{+}$). In many circumstances, the lattice is shown to rearrange within ∼${10}^{\mathrm{-}13}$ s and trap the ${\mathrm{F}}^{+}$ ion, thus blocking desorption. The dynamic lattice distortions are crucial in the determination of which desorption channels are open, which species desorb, and what final kinetic energies are obtained.