Low-energy electron diffraction from disordered surfaces.
In: Institute of Physics Conference Series, Vol. 41: pp. 261-269
Model calculations are presented of L E E D intensities diffracted by a onedimensionally
disordered overlayer adsorbed on a well ordered substrate. Multiple
scattering amplitudes are calculated by an extension of Beeby's multiple scattering
method. The surface layers are divided into overlapping configurations of atoms, the
diffraction of each of which is described by individual scattering amplitudes. In this
way the surrounding of each adsorbed atom is divided into two parts: the immediate
vicinity, in which multiple scattering is treated self-consistently, and the outer region
which is represented by an averaged Τ matrix. The results of the model calculations
indicate that the intensities are not correctly described if only averaged Τ matrices are
used, and that in a first approximation the half-widths of the diffuse streaks observed
in the experiment can be analysed using the kinematic theory.