STRUCTURAL DETERMINATION OF THE SI CU(110) INTERFACE BY PHOTOELECTRONDIFFRACTION/

Deposition of 0.5 Si monolayer (ML) on a Cu(110) surface at room tempe rature (RT) leads to the formation of a c(2 x 2) LEED pattern. In orde r to find out the surface atomic structure of this ordered phase, X-ra y photoelectron diffraction (XPD) azimuthal scans at different photon energies and full hemispherical XPD patterns of the Si 2p core level h ave been measured using both synchrotron radiation and a laboratory so urce. We present an atomic model for the surface structure based on th e examination of forward scattering and first order interference XPD f eatures. Refinement of the structural parameters was achieved by perfo rming single scattering cluster (SSC) calculations. In the proposed mo del Si atoms replace Cu atoms at the surface along the [1 (1) under ba r 0] atomic rows.