Unusual pickup statistics of high-spin alkali agglomerates on helium nanodroplets
J. Chem. Phys. 119, 11124 (2003); doi:10.1063/1.1622930
Issue Date: 1 December 2003
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The pickup of alkali atoms by helium nanodroplets is unusual in that these atoms are not wetted and enveloped by the liquid, but reside in weakly binding surface dimples. As a result, it has been suggested that the alkali clusters which assemble on droplet surfaces must exist in spin-polarized states with a low condensation energy. We consider the size distribution statistics which would be exhibited by the alkali agglomerates in such a case, and show that it would be very different from the conventional Poisson shape. A careful measurement of the variation of the intensities of droplet-grown alkali clusters with size and/or vapor pressure in the pickup region may be able to test the giant-spin hypothesis. ©2003 American Institute of Physics.
| History: | Received 30 June 2003; accepted 9 September 2003 |
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- In principle, any other process leading to copious detachment of alkali complexes without destruction of the helium droplet can raise the tail of the intensity-vs-pressure curve. However, it is difficult to conceive of alternative processes of this type which could simulate the systematic flattened profiles for all cluster sizes as predicted by the spinflip picture. For example, if the metal clusters assemble in their normal ground states, the strength of their attachment to the droplet should increase with cluster size, and one would not then expect to encounter a reproducible detachment mechanism. Thus, evidence derived from pickup profile shapes should be quite suggestive, even if not definitive.








