Quantum effects in the sticking of Ne on a flat metal surface.

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 (1 times 10 sup -3 to 8 times 10 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 for the solid, irrespective of assumed interaction parameters, requiring substantial zero- phonon scattering. Calculations treating the energy transfer to phonons quantum mechanically can reproduce the data with very reasonable parameters.