THE STRUCTURE OF THE Cu111 √3 x √3 R30°-Cl SURFACE : A COMBINED SEXAFS AND PHOTOELECTRON DIFFRACTION STUDYReport as inadecuate




THE STRUCTURE OF THE Cu111 √3 x √3 R30°-Cl SURFACE : A COMBINED SEXAFS AND PHOTOELECTRON DIFFRACTION STUDY - Download this document for free, or read online. Document in PDF available to download.



Abstract : A Surface EXAFS study of the Cu√3 x √3R30°-Cl structure, collecting data above the Cl K-edge in total electron yield on the SRS at Daresbury, indicates that the Cu-Cl distance in this phase is 0.05 ± 0.02Å longer than in bulk CuCl. This result is given by both single shell Fourier filtering analysis and by a multishell simulation treatment. Both analyses also reveal that adsorption is in a 3-fold coordinated hollow site, although neither method is able to distinguish between the two inequivalent 3-fold hollow sites present on this fcc 111 surface. These two sites show identical nearest neighbour contributions to the EXAFS at all polarisation directions, and differ only in the third and higher nearest neighbour shell structure. By contrast photoelectron diffraction data for the Cl 1s photoemission, collected along the 111 and 110 directions, do provide a clear distinction between these sites, showing that the Cl atoms are adsorbed in the same -fcc- sites as the next Cu atom layer would occupy, above 3-fold hollow sites in both the top and second metal atom layers. The complementary nature of these two techniques in the collection and analysis of data is highlighted by this study.





Author: M. Crapper C. Riley P. Sweeney C. Mcconville D. Woodruff R. Jones

Source: https://hal.archives-ouvertes.fr/



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