Threefold-coordinated hollow adsorption site for<i>c</i>(4×2)-NO/Ni(111): A surface-extended x-ray-absorption fine-structure study

Aminpirooz, S.; Schmalz, A.; Becker, L.; Haase, J.

doi:10.1103/physrevb.45.6337

Cited by 68 publications

(25 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Formerly, these two bands were assigned to NO adsorbed at bridge sites in a bent geometry at low coverages, and to an upright geometry at high coverages. Recently, photoelectron diffraction ͑PED͒, 12 surface extended x-ray absorption fine structure ͑SEXAFS͒, 13 and LEED I-V analysis 1,14 have been used to show that the local adsorption site of the NO molecule is a threefold hollow site, contradicting the earlier assignments based on vibrational frequencies alone. Using symmetry arguments in addition to dynamical LEED analysis, Mapledoram et al 14 have shown that the NO molecule is adsorbed in both fcc and hcp threefold hollow sites on Ni͑111͒ at all coverages, and Materer et al 1 have suggested that the two distinct stretching frequencies observed in the HREELS and IRAS spectra are in fact due to dipole-dipole coupling between NO molecules with and without nearest neighbors in the 0.5 ML structure ͑Fig.…”

Section: Introductionmentioning

confidence: 97%

Interadsorbate interactions in the c(4×2) NO/Ni(111) system

Stirniman

Sibener

1995

The Journal of Chemical Physics

View full text Add to dashboard Cite

Electron energy loss spectroscopy has been used to map the dispersion of the dipole active internal NO stretch and of the NO frustrated translation, which has not been previously observed, in the c͑4ϫ2͒ NO/Ni͑111͒ system. The dispersion of the dipole active mode was fit with a model that assumed electrostatic dipole-dipole coupling ͑including image dipoles͒ between the adsorbates. The frustrated translation, on the other hand, showed no dispersion to within the resolution of the experiment across the entire surface Brillouin zone of the Ni͑111͒ substrate. These measurements reveal new information on interadsorbate interactions in an important model system.

show abstract

Section: Introductionmentioning

confidence: 97%

Interadsorbate interactions in the c(4×2) NO/Ni(111) system

Stirniman

Sibener

1995

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…In some cases, however, there were problems related to the fact that the vibrational intensities do not reflect the actual abundance of a species, and in other cases binding site assignments based on the vibrational frequency had to be reconsidered. [1][2][3][4][5][6] Finally this resulted in a set of common, well accepted ordered structures for CO adsorption on transition metals like platinum, rhodium, nickel, copper and palladium. Þ structure at 0.75 ML, and a ''split'' (2 Â 1) or c(6 Â 2) at 0.83 ML coverage.…”

Section: Introductionmentioning

confidence: 99%

On the nature of dense CO adlayers on fcc(100) surfaces: a kinetic Monte Carlo study

Hermse

Jansen

Bavel

et al. 2010

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

We present a kinetic Monte Carlo lattice gas model including top and bridge sites on a square lattice, with pairwise lateral interactions between the adsorbates. In addition to the pairwise lateral interactions we include an additional interaction: an adsorbate is forbidden to adsorb on a bridge site formed by two surface atoms when both surface atoms are already forming a bond with an adsorbate. This model is used to reproduce the low and high coverage adsorption behaviour of CO on Pt(100) and Rh(100). The parameter set used to simulate CO on Pt(100) produces the c(2 x 2)-2t ordered structure at 0.50 ML coverage, a one-dimensionally ordered structure similar to the experimentally observed (3 square root(2) x square root(2)) - 2t + 2b structure at 0.67 ML coverage, the c(4 x 2)-4t + 2b ordered structure at 0.75 ML coverage, and the recently reported c(6 x 2)-6t + 4b ordered structure at 0.83 ML coverage. The (5 square root(2) x square root(2)) ordered structure at 0.60 ML coverage is not reproduced by our model. The parameter set used to simulate CO on Rh(100) produces the c(2 x 2)-2t ordered structure at 0.50 ML coverage, a one-dimensionally ordered structure similar to the experimentally observed (4 square root(2) x square root(2)) - 2t + 4b structure at 0.75 ML coverage, and the c(6 x 2)-6t + 4b ordered structure at 0.83 ML coverage. Additionally, the simulated change of top and bridge site occupation as a function of coverage matches the trend in experimental vibrational peak intensities.

show abstract

“…The system, however, is more complex than that. There are strong repulsive lateral interactions that limit the number of neighboring sites that can be occupied, and which are known to lead to complicated adlayer structures for Ni(1 l l) [92][93][94]. In the simulations we have tried to describe only the short-range order correctly.…”

Section: Temperature-programmed Desorption Spectramentioning

confidence: 99%