Microscopic characterization of the C-F bonds in fluorine-graphite intercalation compounds

The structures of fluorine-graphite intercalation compounds (F-GICs, C_2.8F and C_3.5F) have been analyzed by high-resolution transmission electron microscopy (TEM). Cross-sectional TEM images of the F-GICs indicate that the interlayer distance increases by insertion of fluorine with randomly buckled carbon layers. Such a structure can form by alternation in the bond angle at a carbon atom covalently bonded with fluorine. Electron energy loss spectroscopy combined with TEM indicates that the π-orbital network over the graphitic carbon layer reduces with fluorination. The C-F bond is essentially covalent.