ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Ordered phases of CO on a Ru(0001) surface have been characterized with regard to structural and dynamical properties using high resolution helium atom scattering. In the energy regime below 10 meV a vibrational mode corresponding to a frustrated translation parallel to the surface (FTx) could be identified, the energy amounts to 5.9 meV for isolated CO molecules and to 5.75 meV for the ((square root of 3)×(square root of 3))R30°CO structure. The formation of the more compressed (2(square root of 3)×2(square root of 3))R30°CO and (5(square root of 3)×5(square root of 3))R30°CO structures is accompanied by significant changes of the low energy external vibrations, in pronounced contrast to the gradual frequency increase of the CO internal ν1-vibration. Coadsorption of hydrogen or oxygen was found to result in substantially larger FTx energies. Implications of these findings on the character of the molecule-surface interaction will be discussed, as well as the connection between the FTx-dispersion and the strength and type of the adsorbate-adsorbate interaction. © 1997 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.473828
