Publikationen

Formation probability of metastable molecular hydrogen anions HmDn- (m, n=0-3 and m plus n=2, 3) in sputtering

Autor(en)
Hubert Gnaser, Robin Golser
Abstrakt

The formation of molecular hydrogen anions (H-2(-), D-2(-), HD-, H-3(-), HD2-, and D-3(-)) was investigated. These anion species were produced by sputtering of TiD2 and HfH2 targets with Cs+ ions and were identified by secondary-ion mass spectrometry (SIMS), yielding the corresponding abundance distributions. The intensity ratios of both the diatomic (HD-/D-2(-)) and triatomic (HD2-/D-3(-)) molecular ions are (distinctly) lower than what would be expected from the respective statistical isotopic pattern. This observation indicates that the different lifetimes of these metastable anions are decisive for their formation probability in sputtering and their survival in the mass spectrometer. In addition to molecular ions, the isotopic fractionation of the atomic hydrogen ions, D-/H-, was determined. A strong depletion of the heavier D isotope in the sputtered ion flux by (47.0 +/- 3.1)% was found. This pronounced isotope fractionation could be due to a velocity-dependence of the ionization probability, amplified by the large mass difference of the hydrogen isotopes.

Organisation(en)
Isotopenphysik
Externe Organisation(en)
Technische Universität Kaiserslautern, Institut für Oberflächen- und Schichtanalytik GmbH, Kaiserslautern
Journal
International Journal of Mass Spectrometry
Band
410
Seiten
52-56
Anzahl der Seiten
5
ISSN
1387-3806
DOI
https://doi.org/10.1016/j.ijms.2016.11.004
Publikationsdatum
11-2016
Peer-reviewed
Ja
ÖFOS 2012
103014 Kernphysik
Schlagwörter
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/formation-probability-of-metastable-molecular-hydrogen-anions-hmdn-m-n03-and-m-plus-n2-3-in-sputtering(d308abb1-dab6-4c07-8386-a83a2749b49e).html