Critical Slowing Down of Biaxiality Fluctuations at the Uniaxial-to-Biaxial Phase Transition in a Lyotropic Disklike Nematic Liquid Crystal

M. B. Lacerda Santos; Y. Galerne; G. Durand

doi:10.1103/PhysRevLett.53.787

Critical Slowing Down of Biaxiality Fluctuations at the Uniaxial-to-Biaxial Phase Transition in a Lyotropic Disklike Nematic Liquid Crystal

M. B. Lacerda Santos, Y. Galerne, and G. Durand

Phys. Rev. Lett. 53, 787 – Published 20 August 1984; Erratum Phys. Rev. Lett. 53, 1777 (1984)

Abstract

Using a light-beating, Rayleigh-scattering technique, we observe the thermally excited biaxiality fluctuations which appear in the uniaxial disklike phase of a potassium-laurate, 1-decanol, $D_{2}$ O mixture close to the biaxial phase. The two polarized- and depolarized-mode linewidths undergo a critical slowing down, in agreement with a Landau-type prediction. From the wave-vector dependence of the damping rate, one estimates the bare transverse correlation length to be comparable with 2 micelle diameters.