AVS 45th International Symposium
    Surface Science Division Thursday Sessions
       Session SS-ThP

Paper SS-ThP11
Structure Determination of Si(111)/Sb-(@sr@3x@sr@3)R30@degree@ using Photoelectron Diffraction Direct Methods

Thursday, November 5, 1998, 5:30 pm, Room Hall A

Session: Surface Science Division Poster Session
Presenter: M.C. Asensio, LURE, Centre Universitaire Paris Sud and ICMM, France
Authors: M. Martin, LURE, Centre Universitaire Paris Sud and ICMM, France
H. Ascolani, Centro Atomico Bariloche, Argentina
N. Franco, LURE, Centre Universitaire Paris Sud and ICMM, France
J. Avila, LURE, Centre Universitaire Paris Sud and ICMM, France
M.C. Asensio, LURE, Centre Universitaire Paris Sud and ICMM, France
Correspondent: Click to Email
The determination of the local adsorption structure of absorbed atoms and molecules on single-crystal substrates is a key prerequisite for understanding the electronic and chemical properties of surfaces. Most of the fragments or molecular adsorbates generally present a well defined local order, although, do not form the long-range ordered structures required for conventional LEED studies. One technique applicable to such problems is Photoelectron Diffraction, where the intensity of a core level peak is recorded as a function of the kinetic energy or the emission angle. The spectra measured in this way show intensity modulations which can be strictly correlated with the local structural environment of the atomic emitter. Recently, new direct methods based on energy scan mode have been developed relying on the high scattering factor for 180° backscattering, at low energies. This "backscattering searching" approach requires the measurement of scanned energy spectra at several angles along the high symmetry direction. In the present communication, we report the results of different direct methods for the Si(111)-Sb (@sr@3x@sr@3) structure. The limitations and advantages of each method are analized and the results are contrasted with the final structure obtained by a full multiple scattering trial-and-error analysis.