The Sticking of Ne on Ru(001): Quantum vs. Classical Behavior.

The sticking coefficient of thermal neon atoms on a flat Ru (001) surface (T sub s = 7K) is found experimentally to be very low and strongly dependent on gas temperature (1x10 sup (-3) to 8x10 sup (-2) for T sub g from 600 to 30K) 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 photons quantum mechanically can reproduce the data with reasonable parameters.