Angle-integrated photoemission studies of Ni/Nb(110) and modification of the surface by heat treatment

Journal Article · Thu Sep 15 04:00:00 EDT 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.5805· OSTI ID:6801700

Pan, X; Ruckman, M W; Strongin, M

Angle-integrated photoemission is used to study Ni films supported on Nb(110) and a thermally induced ordered Ni/Nb surface compound. The display-type low-energy electron-diffraction (LEED) patterns suggest that Ni may randomly enter into equivalent surface sites at low coverages (THETAless than or equal to0.5 monolayer (ML)) and agglomerates to form islands at higher coverages. Angle-integrated photoemission spectra for submonolayer Ni coverage show two Ni-derived d states located at -0.7 and -1.5 eV binding energy. Photoemission states typical of Ni metal surfaces are observed above a monolayer coverage. At least two distinct CO chemisorption sites can be deduced from the photoemission data for Ni coverages below 2.5 ML. Thermal treatment of Ni/Nb(110) triggers interdiffusion and reaction which leads to the formation of an ordered Ni/Nb surface compound. We compare the behavior of Ni/Nb(110) to that reported for Pd and Pt/Nb(110) and discuss how the observed changes in the Ni overlayer may affect the chemisorption of carbon monoxide.

• Research Organization: Brookhaven National Laboratory, Upton, New York 11973-5000
• OSTI ID: 6801700
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:9; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ADSORPTION
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISORPTION
DIFFUSION
ELEMENTS
EMISSION
FILMS
HEAT TREATMENTS
INTERFACES
METALS
NICKEL
NIOBIUM
OXIDES
OXYGEN COMPOUNDS
PHOTOEMISSION
SECONDARY EMISSION
SEPARATION PROCESSES
SORPTION
SUBSTRATES
SURFACE PROPERTIES
TRANSITION ELEMENTS