Mainz 2017 – scientific programme
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MS: Fachverband Massenspektrometrie
MS 4: New Methods and Technical Developments
MS 4.1: Invited Talk
Tuesday, March 7, 2017, 14:30–15:00, RW 2
Secondary ion mass spectrometry using large gas cluster ion bombardment — •Hubert Gnaser — Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Germany
The characterization of organic and biological materials by secondary ion mass spectrometry (SIMS) has greatly benefited from the use of cluster ions as primary bombarding species. In particular, large gas cluster ions such as Arn+ (with n > 1000 Ar atoms and an impact energy of about 10 keV) have led to a substantial improvement in those analyses. Using large cluster ions for sputtering, the emission of intact organic and biological molecules from surfaces is often observed. In addition, these "soft" ejection processes result in a pronounced reduction of molecular fragmentation. Thereby, depth profiling and 3D imaging of such specimens became feasible.
In this presentation, the basic processes of the interaction of large cluster ions with solid surfaces are discussed, emphasizing the influence of specific cluster parameters (cluster size, energy per cluster atom) on the emission yields and fragmentation. Furthermore, selective examples of the application of large gas cluster ions in SIMS of organic and biological systems are described.