Lattice dynamics of RbC60, RbC70 and phase transitions in AlC60: a neutron scattering study

Compounds of A1C60 (A = Rb, Cs, K) and RbC70 have been investigated by neutron scattering. The studies include measurements in the high temperature rotator-, the polymer-, the dimer- and the low temperature isolator-phase and include investigations of the particular phase transitions. It is found that each of the phases can be characterized by specific features of its lattice dynamics which can be used for detailed studies of the dynamics of the rotator-polymer and the dimer-polymer transitions. Particular insight in the lattice dynamics is obtained from model calculations for the RbC60 polymer and dimer phase. (orig.)