Sputtered molecular fluoride anions: HfF(n)(-) and WF(n)(-)

Autor(en)

Hubert Gnaser, Robin Golser

Abstrakt

The emission of negatively charged HfFn− (n ≤ 5) and WFn− (n ≤ 7) molecular ions sputtered from a mixed Hf[BOND]W[BOND]PbF2 fluoride sample by a 13 keV Cs+ ion beam was studied. The emitted ions were detected in a high-sensitivity double-focusing secondary ion mass spectrometer. In the HfFn− and WFn− series, HfF5− and WF6− are the anions formed most abundantly, with their ratio amounting to HfF5−/WF6−∼6, whereas HfF5−/WF5−∼18. In particular, the rather high yield of the HfF5− anion could be essential for the sensitive detection of live 182Hf, a radionuclide (half-live ∼9 million years) that might originate from stellar events in the vicinity of the Earth. Generally, these high ion yields appear to correspond with a high electron affinity of the respective molecule. In addition, their formation may be affected by the atomic composition at the sputtering site. Because their constituents originate from (initially) separated sources (the individual Hf, W and PbF2 particles), the production of the HfFn− and WFn− molecular anions is envisaged to require an extensive mixing between these different reservoirs during sputtering. Furthermore, the energy distributions of these molecular anion species indicate that they are released from the surface via a collision cascade that also leads to the occurrence of fragmentation processes in the emission event.

Organisation(en)

Isotopenphysik

Externe Organisation(en)

Technische Universität Kaiserslautern

Journal

Surface and Interface Analysis

Band

43

Seiten

32-35

Anzahl der Seiten

4

ISSN

0142-2421

DOI

https://doi.org/10.1002/sia.3442

Publikationsdatum

2011

Peer-reviewed

Ja

ÖFOS 2012

103005 Atomphysik

Link zum Portal

https://ucris.univie.ac.at/portal/de/publications/sputtered-molecular-fluoride-anions-hffn-and-wfn(fad73c7c-2875-4305-97ce-05099db7360d).html