Quasi-elastic and inelastic neutron scattering in the high temperature phase of the cooperative Jahn-Teller system CsCuCl3

Quasi-elastic and inelastic neutron measurements have been performed to study the high-temperature phase of the cooperative Jahn-Teller system CsCuCl 3 . A strong coupling between phonons and dynamic reorientation processes of the distorted CuCl 6 octahedra dipole-dipole interactions using the concept of pseudo-spins for describing the orientational disorder of the Jahn-Teller distorted octahedra, it is possible to interpret the characteristic features of the quasi-elastic and inelastic scattering in a unified picture. The relaxation rate of the reorientation processes was determined as 2*10 10 s -1 and it is shown that the warping energy can be derived from a systematic measurement of the relaxation rate as a function of temperature.