ausblenden:
Schlagwörter:
Ammonia
Chemisorption
Copper
Low index crystal surfaces
Photoelectron diffraction
Surface structure, morphology, roughness, and topography
Zusammenfassung:
The local adsorption structure of ammonia on Cu(110) has been determined in a quantitative fashion using N 1s scanned-energy mode photoelectron diffraction. While inversion of the photoelectron diffraction spectra using a direct method indicates that the adsorbed NH3 molecules are near to atop sites, a fuller multiple scattering analysis shows that the molecule is actually displaced 0.37 Å off the atop site in a 〈100〉 azimuth. The result is ascribed to adsorbate-adsorbate interactions (steric hindrance) similar to those found in (2 × 1)-CO (pmg) structures seen on several fcc (110) surfaces, although in the case of ammonia, it occurs at coverages well below saturation, implying that adsorbate-adsorbate attraction also occurs. These general conclusions are entirely consistent with those of a recent ESDIAD study of this system.
