Abstract
Quasielastic neutron scattering (QNS) measurements carried out for heptyloxyazoxybenzene (HOAB) revealed the existence of fast molecular reorientation in the nematic and smectic C phases. The correlation time of this process, derived by fitting to a uniaxial rotational diffusion model, is of order of 10–20 ps in both liquid crystal phases. An explanation of the reasons for the disagreement between the correlation time values obtained by methods based on QNS and dielectric relaxation in the microwave region is suggested.