Determination of Sulphur Coordination to the Two-Fold Hollow Site of Ni(110) Using Polarization-Dependent SEXAFS
02 October 1987
We have used the technique of surface EXAFS (SEXAFS) to study the structure of the Ni(110)c(2x2)S adsorption phase. The SEXAFS measurements employed the Auger-yield mode, monitoring S KLL emission above the S K-edge in both near-normal and grazing incidence geometries.
The data show that S lies in the rectangular hollow site, bonding to one Ni atom in the second layer and to four atoms in the surface plane, with bond distances of 2.23+-0.04angstrom and 2.31+-0.02angstrom , respectively. This indicates a first- nickel-layer relaxation of ca. 12% from the bulk value, in broad agreement with the results of other techniques.