Quantum Effects in the Sticking of Ne on a Flat Metal Surface

Abstract

The sticking coefficient of thermal neon atoms on a flat Ru(001) surface (${T}_{s}=7$ K) is found experimentally to be very low and strongly dependent on gas temperature (1\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}3}$ to 8\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}2}$ for ${T}_{g}$ from 600 to 30 K) on the clean surface, and to increase strongly with coverage to about 0.7. The zero-coverage values are incompatible with classical mechanical theory, irrespective of assumed interaction parameters, requiring substantial zero-phonon scattering. Calculations treating the energy transfer to phonons quantum-mechanically can reproduce the data with reasonable parameters.