Vibrational spectroscopic studies of adsorbates on bimetallic surfaces

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7044630

Kuhn, W K

In this work, well-defined bimetallic surfaces have been studied using carbon monoxide adsorption in conjunction with infrared reflection absorption spectroscopy (IRAS). These studies have indicated that for CO adsorbed on Cu overlayers, the bond between the CO and the Cu adatoms is comprised of both [pi]-backdonation and polarization interaction components. The sum of the contributions from these effects determines the observed bond strength with the observed CO stretching frequency being determined by the relative contributions of the components. In addition, it was determined that IR spectra of adsorbed CO show a remarkable sensitivity to surface structure. Three-dimensional Cu clusters, well-ordered two dimensional Cu islands and isolated Cu atoms are distinctively characterized by their CO IR peaks. In addition, both disorder-order and order-order transitions are observed for the metal overlayers on the single crystal metal substrates. It was also observed that localized segregation and ordering of mixed Co and S overlayers on a Mo(110) substrate occurs upon annealing.

• Research Organization: Texas A and M Univ., College Station, TX (United States)
• OSTI ID: 7044630
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ADSORPTION
BIMETALS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL BONDS
COPPER
ELEMENTS
ENERGY LEVELS
EXCITED STATES
INFRARED SPECTRA
METALS
MOLYBDENUM
NONMETALS
ORDER-DISORDER TRANSFORMATIONS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
SORPTION
SPECTRA
SULFUR
SURFACE PROPERTIES
TRANSITION ELEMENTS
VIBRATIONAL STATES