151Eu Mössbauer experiments on EuC13-Alcl3 graphite flakes and HOPG samples have been performed as a function of temperature in the range 4.2K < T < 300K and indicate the presence of a narrow line characteristic of Eu3+. No evidence of Eu2+ was found. This suggests that enhanced conductivity of graphite upon intercalation with rare earth chlorides derives from a transfer of charge to the co-intercalated Cl.

In situ 57Fe Mössbauer spectra are reported for the first-, higher-stage ferric chloride, and a mixed ferric chloride-potassium chloride intercalated graphite catalysts under reduction and Fischer-Tropsch reaction conditions. The mass spectroscopic measurements reveal a different catalytic selectivity for the three catalysts. The first two catalysts predominantly possess a higher selectivity for methane, whereas the third catalyst has higher selectivity for the formation of propane. The differences are attributed to geometrical effects in the catalytic sites of the intercalated compounds.

A new technique utilizing nuclear resonance scattering of photons from isolated nuclear levels in the 6-9 MeV range is being used for studying the orientation of certain intercalant molecules with respect to the graphite (G) planes. This technique may be applied to intercalants containing 11B, 15N, 39K, 48Ti, 50Cr, 56Fe, 62Ni and 68Zn. As an example, the orientation of the HNO3 molecules intercalated in HOPG was studied by photon scattering from the 6.324 MeV level in 15N. Thus in C10 (HNO3) and C15(HNO3), the NO3 planes were found to be oriented at θ ˜ 90° relative to the G planes, while in the mixture of the ‘residue’ compounds C16(HNO3) and C24(HNO3), the NO3 planes were found to be nearly parallel, θ0 < 25°, relative to the G-planes.