Effect of sulfur on oxygen adsorption and oxidation of the Ni(111) surface
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States)
The effect of sulfur (S) on oxygen chemisorption and the initial stages of oxidation of the Ni(111) crystal surface have been studied with Auger electron spectroscopy, low-energy electron diffraction, and x-ray photoelectron spectroscopy at room temperature under ultrahigh vacuum conditions. It is found that sulfur strongly retards the oxygen adsorption kinetics, but does not change the oxidation mechanism. The initial chemisorption sticking coefficient ({ital s}) is found to follow the relationship {ital s} {proportional to} (1 {minus} 3{theta}{sub {ital s}}){sup 2}, where {theta}{sub {ital s}} is the S coverage. Oxidation of S precovered surfaces can be described fairly well by an island growth model; the decrease in oxidation rate, relative to that of the S-free surface, can be attributed to the reduction in the density of oxide nuclei. Some experimental observations indicate that the oxide layer is partially removed by S at 440 K. Sulfur is believed to remain at the Ni/NiO interface during oxidation.
- DOE Contract Number:
- FG02-87ER45328
- OSTI ID:
- 7291891
- Journal Information:
- Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Vol. 10:4; ISSN 0734-2101
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
NICKEL
OXIDATION
OXYGEN
CHEMISORPTION
SULFUR
ADSORPTION
SURFACES
TEMPERATURE RANGE 0273-0400 K
ULTRAHIGH VACUUM
CHEMICAL REACTIONS
ELEMENTS
METALS
NONMETALS
SEPARATION PROCESSES
SORPTION
TEMPERATURE RANGE
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties