DIRECT DETERMINATION OF RELAXATION PARAMETER FROM LEED INTENSITY PATTERNS WITH THE SINGLE OVERLAYER RELAXED STRUCTURE MODEL

Abstract

Using the analytical formulae for Low Energy Electron Diffraction (LEED) intensity patterns in the layer doubling method, we have shown that the relaxation parameter for single overlayer relaxed structure can be solved. Although it is difficult to obtain analytically, numerical method based on linear approximation successfully retrieves the parameter value for simulated pseudo-experimental data. This method uses the intensity pattern along the geometry and the chemistry of the bulk to solve the parameters and it may be thought of as a precursor to a full-fledged method for direct determination of surface structure from LEED pattern. Application of this method on the experimental data of Rh(110), which is known to be a two-overlayer relaxed structure, did not yield a single cluster of relaxation parameters. However, qualitative feature of contraction of top layer relaxation parameter has been properly retrieved at different energies.