ELECTRON-STIMULATED AND PHOTON-STIMULATED DESORPTION AS A PROBE OF THE DYNAMICS OF MOLECULES ON SURFACES

This work examines the properties of excited molecules emitted from gas-dosed alkali-metal and alkali-halide surfaces due to electron- and photon-stimulated desorption (ESD and PSD) to elucidate molecular surface dynamical processes. Our measurements indicate that (1) CN adsorbates are generated when alkali-rich surfaces are exposed to gaseous CO2 and N2 molecules, (2) OH adsorbates are generated from exposure of the surfaces to gaseous H-2 and CO2, (3) cross sections for CN* ESD and excitation functions for CN* PSD depend on alkali-CN parent bonds on the surface, and (4) rotational distributions of the electronically desorbing excited CN exhibit temperature-independent non-Boltzmann features which systematically depend on substrates. This research demonstrates that desorbing molecules, arising from ESD and PSD, constitute an internal-state-resolved and surface-bond-sensitive probe which gives information on the static and dynamic properties of surface molecular systems.