Photochemistry of O{sub 2} on Ag(110) using picosecond ultraviolet laser pulses

Journal Article · Wed May 01 04:00:00 EDT 1996 · Journal of Vacuum Science and Technology, A

DOI:https://doi.org/10.1116/1.580294· OSTI ID:284670

Erkkila, V J; Hoffbauer, M A ^[1]; White, J M ^[2]

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1. Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712 (United States)

Surface second-harmonic generation (SHG) was used to study the photochemical reaction of O{sub 2} with Ag(110) using {approximately}6 ps laser pulses. A clean well-ordered Ag(110) surface produces a strong SHG signal at 580 nm. The SHG signal measured in real time during O{sub 2} exposure is sensitive to submonolayer coverages of O{sub 2} and to the subsequent exposure of this system to picosecond ultraviolet laser pulses. Upon O{sub 2} adsorption at 130 and 200 K, the signal decreases by more than a factor of 2 at saturation coverage. Langmuir adsorption kinetics are used to fit the O{sub 2} dosage curves relating the decrease in SHG intensity to the oxygen coverage. Subsequent exposure of the surface dosed at 130 K to 290 nm light of the same pulse width also produces a change in the second-harmonic response. Combined with surface SHG temperature programmed desorption measurements, these results are correlated to the photochemical reaction taking place on the surface in which chemisorbed O{sub 2} photodissociates and photodesorbs. The results of the surface photochemical reaction initiated by picosecond UV pulses are compared to those previously studied using continuous wave radiation and are found to have similar overall behavior while possibly showing some new features. {copyright} {ital 1996 American Vacuum Society}

• OSTI ID: 284670
• Report Number(s): CONF-9510385--
• Journal Information: Journal of Vacuum Science and Technology, A, Journal Name: Journal of Vacuum Science and Technology, A Journal Issue: 3 Vol. 14; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
CHEMISORPTION
DESORPTION
DISSOCIATION
HARMONIC GENERATION
LASER RADIATION
OXYGEN
PHOTOCHEMICAL REACTIONS
SILVER
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
ULTRAVIOLET RADIATION