The in-plane structure and dynamics of the intercalant Cs layer in CsC24 was studied by Cs133 quadrupole-perturbed NMR spectra and quadrupolar spin-lattice relaxation. The results showed that the dominant excitations leading to the disordering of the mixed commensurate-incommensurate structure were phonon-like shear modes interrupted by diffusion and displaying softening as the temperature approaches the de-intercalation temperature.

Diffusion and Phononlike Excitations in Intercalated Graphite from Cs133 NMR and Relaxation. Borsa, F., Corti, M., Rigamonti, A., Torre, S.: Physical Review Letters, 1984, 53[22], 2102-5