Theory of diffuse neutron scattering in the high temperature phase of CsCuCl3 and related Jahn-Teller compounds

The hexagonal Jahn-Teller compounds ABCl₃ (A=Cs, Rb; B=Cu, Cr) in their common high temperature phase are modeled as a system of independent elastic dipoles dressed by a far reaching strain field. The diffuse elastic cross section for neutrons is derived as for Huang scattering. Isointensity contours and line widths (FWHM) are calculated for CsCuCl₃ and compared to experimental results, especially looking for correlations and precursor effects of the structural phase transition.