Neutron scattering of the TO phonon in CuCl at 5K

Abstract

By inelastic coherent neutron scattering experiments performed in various Brillouin zones, it is shown that the lineshape of the TO phonon at, and in the vicinity of, q=0 has a double peak structure. The analysis of the data confirms and extends a previously proposed model in which this line shape is explained by a strong interaction between the harmonic TO phonon (the dispersion of which is here obtained) and a two-phonon density of states which is found to be independent of q.