Studies of bimetallic surfaces using infrared reflection absorption spectroscopy

Journal Article · Wed Jul 01 04:00:00 EDT 1992 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.578085· OSTI ID:7111461

Kuhn, W K; He, J; Goodman, D W ^[1]

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1. Department of Chemistry, Texas A M University, College Station, Texas 77843-3255 (United States)

Well-defined bimetallic surfaces have been studied using carbon monoxide adsorption in conjunction with infrared reflection--absorption spectroscopy. The vibrational frequency of CO on low Cu coverages ({similar to}0.1 monolayer (ML)) on Rh(100) and Mo(110) is blue-shifted relative to its gas phase stretching frequency of 2143 cm{sup {minus}1}. This blue shift is explained as arising from CO adsorbed on well-dispersed Cu adatoms which are slightly positively charged due to polarization arising from the CO--Cu interaction. As the sample temperature is increased to 150--200 K, CO becomes mobile on these surfaces as evidenced by the migration of CO from submonolayer Pd overlayers to a W(110) substrate. Three-dimensional Cu clusters, well-ordered pseudomorphic two-dimensional Cu islands, and single Cu atoms are distinctively characterized by their CO infrared (IR) peaks. In addition, it is found that IR spectra of adsorbed CO show a remarkable sensitivity to surface structural phase transitions. Both order--order and disorder--order transitions are observed for Ni and Co overlayers on a Mo(110) substrate. It is further shown that localized segregation and ordering of C and O on Mo(110), B on Ru(0001) and Co on S/Mo(110) are observable.

• OSTI ID: 7111461
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States) Vol. 10:4; ISSN JVTAD; ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ADSORPTION
BIMETALS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISORPTION
COATINGS
COBALT
COPPER
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FILMS
INFRARED SPECTRA
INTERFACES
METALS
MOLYBDENUM
MORPHOLOGY
NICKEL
ORDER-DISORDER TRANSFORMATIONS
OXIDES
OXYGEN COMPOUNDS
PALLADIUM
PHASE TRANSFORMATIONS
PLATINUM METALS
RHODIUM
RUTHENIUM
SEGREGATION
SEPARATION PROCESSES
SORPTION
SPECTRA
SPECTRAL SHIFT
THIN FILMS
TRANSITION ELEMENTS
TUNGSTEN
VIBRATIONAL STATES