Collision-induced desorption of water from Ru(001)

Abstract

The effect of energetic rare-gas colliders in a supersonic beam on the interaction of H₂O and D₂O with Ru(001) is discussed. It was found that molecules which are thermally desorbed near 180 K, the A₂ state for both H₂O and D₂O, undergo selective collision-induced desorption (CIDE) following collisions with energetic Kr. Threshold energies for CIDE are 3.4 eV for H₂O and 3.8 eV for D₂O, consistent with the already known isotope effect in the temperature-programmed desorption (TPD) spectra of these molecules. Ice features which are thermally less stable than the A₂ molecules, being desorbed near 160 K, are not affected by collisions at energies up to 5.0 eV. This observation indicates that kinetic energy dissipation by the hydrogen-bonded network is extremely efficient.