The angular distributions of Pt 4f7/2 and 4f5/2 photo-electrons were measured for the reconstructed (110) 1 x 2 surface, at 6 different kinetic energies ranging from 120 to 370eV, by using an angle multi-channel analyzer. From the photo-electron diffraction patterns, holographic reconstructions were performed by using the single wave number reconstruction method and the multiple wave number phased sum method. The results which were obtained from the 2 photo-emission lines were very similar in general. In the case of single energy reconstruction, the quality of the reconstructed images depended strongly upon the kinetic energy of the photo-electrons. At high kinetic energies (370eV), the reconstructed images were dominated by maxima which were attributed to nearest neighbors in the plane above the emitter. At low kinetic energies (120eV), artefacts predominated. The multiple wave number algorithm led to strong twin-image suppression and to a reduction in certain artefacts, but did not noticeably improve the resolution. Although the overall quality of the reconstructed images was increased when using the multiple energy algorithm, the best quality was observed in the case of single energy reconstruction; for a kinetic energy of about 370eV. In all cases, the atomic positions were shifted from their true values by 0.02 to 0.03nm; due to phase shifts during the scattering process.

M.Zharnikov, D.Mehl, M.Weinelt, P.Zebisch, H.P.Steinrück: Surface Science, 1994, 312[1-2], 82-96