Surface location of alkaline-earth atom impurities on helium nanodroplets

Abstract

There has been notable uncertainty regarding the degree of solvation of alkaline-earth atoms, especially Mg, in free He-4 nanodroplets. We have measured the electron energy dependence of the ionization yield of picked-up atoms. There is a qualitative shape difference between the yield curves of species solvated in the middle of the droplet and species located in the surface region; this difference arises from the enhanced role played by the Penning ionization process in the latter case. The measurements demonstrate that Mg, Ca, Sr and Ba all reside at or near the droplet surface.

11 pages, 3 figures

References in corpus (2)

• The structure and energetics of ${}^3$He and ${}^4$He nanodroplets doped with alkaline earth atoms
• Predicting atomic dopant solvation in helium clusters: the MgHe${}_n$ case

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• Minimum sizes for the submersion of alkali clusters into liquid helium
• Absorption spectrum of Ca atoms attached to ${}^4$He nanodroplets
• Mg impurity in helium droplets
• Quantum-State-Sensitive Detection of Alkali Dimers on Helium Nanodroplets by Laser-Induced Coulomb Explosion
• Photoinduced molecule formation of spatially separated atoms on helium nanodroplets