IMAGING OF A SURFACE ALLOY WITH ENERGY-DEPENDENT PHOTOELECTRON HOLOGRAPHY

Fourier transformation of experimental energy-dependent photoelectron diffraction data has been used to produce an essentially artifact-free image of a surface alloy. This direct method, based upon the intersec tion off contour arcs associated with each measurement direction, can provide vectorial atomic positions with atomic resolution. A rapid dat a collection mode was introduced. Surface structural sensitivity was c onfirmed by comparison with multiple-scattering simulations. The previ ously ambiguous surface geometry of c(2x2)Au/Cu(001) has been determin ed, with clear, non-model-dependent discrimination of the surface allo y over the overlayer structure.