ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Photostimulated desorption of NO chemisorbed on a Pt(100) surface at 80 and 300 K has been studied with an ArF excimer laser (λ=193 nm) and a positive-ion measurement system. NO+ is the only ion species observed when a NO-saturated Pt(100) surface is irradiated with laser light. The NO+ yield is proportional to the third power of laser fluence. The translational-energy distribution of the NO+ ions is independent of laser fluence. We propose a two-step model as the most probable NO+ formation mechanism. The first step is desorption of neutral NO induced by valence-electron excitation in chemisorbed NO with one-photon absorption. Then, the desorbed NO is ionized in the vicinity of the surface via the two-photon nonresonant ionization process. Relatively large desorption cross sections estimated from the decay of the NO+ yield support the above NO+ formation mechanism.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.457445
Permalink