title: Spectroscopy and Dynamics of K Atoms on Argon Clusters.
abstract: We present a combined experimental and simulation study of the 4s → 4p photoexcitation of the K atom trapped at the surface of ArN clusters made of a few hundred Ar atoms. Our experimental method based on photoelectron spectroscopy allows us to firmly establish that one single K atom is trapped at the surface of the cluster. The absorption spectrum is characterized by the splitting of the atomic absorption line into two broad bands, a Π band associated with p orbitals parallel to the cluster surface and a Σ band associated with the perpendicular orientation. The spectrum is consistent with observations reported for K atoms trapped on lighter inert gas clusters, but the splitting between the Π and Σ bands is significantly larger. We show that a large amount of K atoms are transiently stuck and eventually lost by the Ar cluster, in contrast with previous observations reported for alkaline earth metal systems. The excitation in the Σ band leads systematically to the ejection of the K atom from the Ar cluster. On the contrary, excitation in the Π band leads to the formation of a bound state. In this case, the analysis of the experimental photoelectron spectrum by means of nonadiabatic molecular dynamics simulation shows that the relaxation drives the system toward a basin where the coordination of the K atom is 2.2 Ar atoms on the average, in a poorly structured surface.
authors: †Unité mixte CEA-CNRS-ENSICAEN-UCBN 6252 BP 5133, CIMAP, F-14070 Caen, Cedex 05, France.
authors: J
authors: J
authors: Douady
authors: ‡Laboratoire Francis Perrin, URA 2453, CEA/IRAMIS/LIDYL, F-91191 Gif-sur-Yvette, France.|§EMIR, Institut Préparatoire aux Etudes d'Ingénieurs de Monastir (IPEIM), 5019 Monastir, Tunisie.
authors: S
authors: S
authors: Awali
authors: ∥Laboratoire Francis Perrin, URA 2453, CNRS/IRAMIS/LIDYL, F-91191 Gif-sur-Yvette, France.
authors: L
authors: L
authors: Poisson
authors: ∥Laboratoire Francis Perrin, URA 2453, CNRS/IRAMIS/LIDYL, F-91191 Gif-sur-Yvette, France.
authors: B
authors: B
authors: Soep
authors: ∥Laboratoire Francis Perrin, URA 2453, CNRS/IRAMIS/LIDYL, F-91191 Gif-sur-Yvette, France.
authors: J M
authors: JM
authors: Mestdagh
authors: †Unité mixte CEA-CNRS-ENSICAEN-UCBN 6252 BP 5133, CIMAP, F-14070 Caen, Cedex 05, France.
authors: B
authors: B
authors: Gervais