One-phonon scattering of atoms in three dimensions by a simplified continuum model of a surface: Thermal desorption

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Abstract
A model of thermal desorption of atoms from surfaces is presented. The treatment is quantum mechanical, and calculations are made using the first‐order distorted‐wave Born approximation, within the one‐phonon approximation. The atom–surface interaction potential is a Morse potential, and the modal properties of the surface are those of a bulk continuum, the work being a natural continuation of some earlier atom–surface scattering work of Goodman. Our conclusions are inconsistent with some of those of Bendow and Ying and Ying and Bendow, who reported pre‐exponential factors τ0 of order 10−5 s in the standard Frenkel formula for desorption; our values of τ0 are more in accord with the previously accepted values, of order 10−12 s. We apply the model to the astrophysical system H–C, and to interpretation of some experimental data on the systems He–Ar, He–Kr, and He–Xe; we find satisfactory agreement with experiment.