ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Ultraviolet photoelectron spectra have been measured for pulsed supersonic beams of krypton and xenon as dilute mixtures in helium. The spectra exhibit broad bands which are located at lower ionization energies relative to the monomer ion states, 2P3/2 and 2P1/2, with which they correlate. The structural features of the spectra, particularly in the first band group, become more complex with increasing condensation, apparently relating to the mean cluster size associated with each spectrum. The spectra are interpreted using the cluster-size dependent core-ion model developed to explain the analogous spectra of the argon clusters. The argon clusters spectra were interpreted as showing the presence of Ar+3, Ar+7, and Ar+13 core ions, with Ar+3 involved in the ionization of small neutral clusters, and Ar+13 produced by the dominant ionization mechanism in large clusters as well as in solid argon. The krypton and xenon clusters show variations of this behavior. The relatively large spin-orbit splitting of the Kr+ and Xe+ p-hole states is reflected in the two band groups observed in the respective Kr and Xe clusters spectra. The lower ionization energy band group in each case exhibits structural features similar to those observed for the argon clusters spectra. The krypton spectra indicate, that for the largest clusters, all three core-ion mechanisms are operative; whereas, for xenon, the largest clusters show only the triatomic core ion, Xe+3, as involved in the ionization mechanism. The high pressure clusters spectra of argon, krypton, and xenon are effectively identical with those reported for their respective condensed thin films, indicating that these variations in the core-ion mechanism of ionization are also responsible for the differences observed in the ultraviolet photoemission spectra of the rare-gas solids.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.461062
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