INPLANE PHONON DENSITY-OF-STATES OF LI-GRAPHITE INTERCALATION COMPOUNDS

The in-plane phonon densities of states of Li-graphite intercalation c ompounds of stage-1 and stage-2 are obtained from neutron time-of-flig ht spectra. For the stage-2 the ordered compound LiC12 which has the s ame inplane structure as the stage-1 compound LiC6 as well as the dilu te compound LiC16 which only reveals short range order were studied, T he temperature in the measurements was extended above expected phase t ransitions for both stages and the density of states is analysed in te rms of the effective temperatures T-parallel to for the in-plane vibra tional energies. T-parallel to shows characteristic changes at the the rmodynamic temperatures of the phase tansitions. Comparison of the T-p arallel to values shows similar in-plane dynamics of all Li-compounds at the highest temperatures.