APPLICATION OF CHEMICAL TENSOR LEED TO MOXRE1-X(100) SURFACES

We present and apply an extension of the perturbation method tensor LEED in order to handle surface stoichiometry, i.e. the substitution of surface atoms by chemically different species. This avoids the need for new full dynamical calculations for surfaces of different chemical composition and allows fast access to their LEED intensities. This ''chemical tensor LEED'' is applied to the chemically disordered alloy MoxRe1-x(100) for x = 0.75, 0.85 and 0.95 for which LEED intensities were measured. Oscillatory layer dependent segregation is found in agreement with conventional LEED analyses. Even small Re concentrations strongly modify the structure of the pure Mo(100) surface, i.e. the surface reconstruction is lifted and multilayer relaxation effects are increased.