The dielectric fluctuations in the uniaxial nematic phase of a bent-core liquid crystal have been studied by dynamic light scattering. Polarization selection of the scattering cross-section reveals one mode due to ordinary director fluctuations and, in the lower part of the nematic phase, a second mode attributable to fluctuations of the biaxial order parameter. The director fluctuations are $\sim 100$ times slower than observed in typical nematics based on straight-core molecules, suggesting that the bent core nematogenic units may be microscopic smectic domains (“cybotactic” clusters).

• Received 10 September 2002

DOI:https://doi.org/10.1103/PhysRevE.66.060701