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Evidence for valence hole localization in the Auger decay and fragmentation of carbon and silicon tetrafluorides

Journal Article · · J. Chem. Phys.; (United States)
DOI:https://doi.org/10.1063/1.456011· OSTI ID:6548967
Monochromatic synchrotron radiation was used to excite selectively core electrons of the carbon and fluorine atoms in carbon tetrafluoride and silicon and fluorine in silicon tetrafluoride. The fragmentation processes were examined using time-of-flight mass spectroscopy. The mass spectra show the distribution of ions collected in coincidence with low and high energy electrons. Distinct changes in the mass spectra with atomic site of excitation and photon energy are observed. The observation of F/sup 2 +/ ions following fluorine 1s excitation in SiF/sub 4/ provides significant evidence for a ''valence bond depopulation'' mechanism involving the formation of a localized, two-hole final state that persists on the time scale of fragmentation. In contrast, no F/sup 2 +/ was observed for CF/sub 4/, which indicates that fragmentation for this molecule is more characteristic of a delocalized two-hole state.
Research Organization:
Department of Chemistry, State University of New York, Stony Brook, New York 11794-3400
OSTI ID:
6548967
Journal Information:
J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 90:4; ISSN JCPSA
Country of Publication:
United States
Language:
English