Very high atomic oxygen coverages on Ru(001)

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

DOI:https://doi.org/10.1116/1.578100· OSTI ID:7111295

Malik, I J; Hrbek, J ^[1]

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1. Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)

Very high oxygen coverages{minus}up to {theta}{sub {ital O}} {approx} 40 (forty){minus}were obtained by dissociative adsorption of NO{sub 2} on Ru(001) at elevated temperatures. O{sub 2} desorption data show three desorption peaks at {approx}1100, {approx}1000, and {approx}900 K, and suggest strong oxygen--oxygen repulsions in the overlayer. An Arrhenius plot of the leading edge desorption rates of the 900 K peak yields {ital E}{sub {ital A}} = 53 kcal/mol, implying zero-order desorption kinetics. O{sub 2} is the only desorption product for {theta}{sub {ital O}}{lt} 3; additional RuO{sup +}{sub x} ({ital x}=0--3) species were detected at higher coverages. However, neither the O 1{ital s} and Ru 3{ital d} core levels, nor the valence band spectra showed any evidence for chemical changes, i.e., an oxide formation. The process of an underlayer formation as a distinct stage in the oxidation of the Ru metal will be discussed in terms of a model for subsurface penetration of O on transition metals.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7111295
• 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
360105* -- Metals & Alloys-- Corrosion & Erosion
ARRHENIUS EQUATION
CHALCOGENIDES
CHEMICAL REACTIONS
DESORPTION
ELEMENTS
EQUATIONS
METALS
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
RUTHENIUM
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES
TRANSITION ELEMENTS
VALENCE