Far-infrared magnetoreflection studies of graphite intercalated with bromine

An estimate of the hole generation rate in graphite-bromine residue compounds has been made from the interpretation of far-infrared magnetoreflection data. From the cutoff of the (1,2) Landau level transition due to the lowering of the Fermi energy upon bromine intercalation, we estimate that one hole is generated by 55 ± 10 Br2 intercalate molecules. This result is shown to be consistent with estimates based on transport measurements. Furthermore, the observed magnetoreflection resonances confirm that for these compounds (1 mole% Br2) the electronic structure in the band overlap region is well described by the Slonczewski-Weiss-McClure band model for approximately the same values of the band parameters as for pure graphite.