Scattering of atoms by solid surfaces: Critical review of the lennard-jones, devonshire and strachan theory of inelastic gas-surface interactions, and some improvements

Abstract

A critical review is given of the present quantum theory of inelastic gas-surface interactions, due to Lennard-Jones, Devonshire and Strachan; this theory is, essentially, a first-order one-phonon theory in one dimension. At the same time, several improvements and generalizations are made to the theory; examples of these are: (1) a notation is developed which is easier to handle than are previous notations, (2) results are presented for arbitrary surface temperature, (a) for a single incident gas atom and (b) for arbitrary incident gas temperature, (3) the effects of bound states of the gas atom at the surface are considered in more detail, (4) the unitary correction suggested by Cabrera, Celli, Goodman and Manson is applied, where possible, to the results, (5) the questions of the ranges of validity of the first-order and of the one-phonon approximations are considered and (6) some consequences of the use of a one-dimensional model are discussed. It is concluded that there are some major difficulties associated with the present theory, and that a three-dimensional theory is required.