The local adsorption geometry of benzenethiolate on Cu(100)

SURFACE SCIENCE

卷:602

Article

Allegretti, F.¹  Bussolotti, F.²  Woodruff, D. P.¹  Dhanak, V. R.^3,4,5  Beccari, M.⁶  Di Castro, V.⁶  Betti, M. G.²  Mariani, C.² 

[1] Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England

[2] Univ Roma La Sapienza, Dipartimento Fis, CNISM, CNIS, I-00185 Rome, Italy

[3] Univ Liverpool, Dept Phys, Liverpool L69 3BX, Merseyside, England

[4] Univ Liverpool, Surface Sci Res Ctr, Liverpool L69 3BX, Merseyside, England

[5] STFC Daresbury Lab, Warrington WA4 4AD, Cheshire, England

[6] Univ Roma La Sapienza, Dipartimento Chim, I-00185 Rome, Italy

关键词: surface structure;    X-ray standing waves;    NEXAFS;    photoelectron diffraction;    copper;    benzenethiol;    chemisorption;   

DOI  :  10.1016/j.susc.2008.05.032

来源: Elsevier

【 摘 要 】

The local adsorption geometry of benzenethiolate in the ordered c(2 x 6) phase on Cu(100) has been investigated by a combination of S K-edge near-edge X-ray absorption fine structure (NEXAFS), normal incidence X-ray standing waves (NIXSW) and S is scanned-energy mode photoelectron diffraction (PhD). NEXAFS and PhD show that the molecular plane is tilted from the surface normal by 20 15, while NIXSW clearly identifies the S head-group as occupying the four-fold coordinated hollow sites. PhD shows the S atoms lies 1.34 +/- 0.04 angstrom above the outermost Cu atomic layer, leading to a Cu-S bond-length of 2.25 +/- 0.02 angstrom. The combination of the PhD and NIXSW results shows the Cu surface layer has an outward relaxation of 0.15 +/- 0.06 angstrom. Possible origins for this large adsorbate-induced relaxation are discussed. (C) 2008 Elsevier B.V. All rights reserved.

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