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arXiv · 0710.1218

Luminescence evidence for bulk and surface excitons in free xenon clusters

O. G. Danylchenko·Yu. S. Doronin·S. I. Kovalenko·M. Yu. Libin·V. N. Samovarov·V. L. Vakula
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Abstract

Cathodoluminescence spectra of free xenon clusters produced by condensation of xenon-argon gas mixtures in supersonic jets expanding into vacuum were studied. By varying initial experimental parameters, including xenon concentration, we could obtain clusters with a xenon core (300-3500 atoms) covered by an argon outer shell as well as shell-free xenon clusters (about 1500 atoms). The cluster size and temperature (about 40 K for both cases) were measured electronographically. Luminescence bands evidencing the existence of bulk and surface excitons were detected for shell-free xenon clusters. The emission from bulk excitons in small clusters is supposed to be due to processes of their multiple elastic reflections from the xenon-vacuum interface. A presence of an argon shell causes extinction of the excitonic bands. In addition, some new bands were found which have no analogs for bulk xenon cryosamples.

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O. G. Danylchenko, Yu. S. Doronin, S. I. Kovalenko, M. Yu. Libin, V. N. Samovarov, V. L. Vakula. 2007-10-05. Luminescence evidence for bulk and surface excitons in free xenon clusters. https://doi.org/10.1103/physreva.76.043202

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