Determination of orientational correlation functions in ordered fluids: Raman scattering

Abstract

Fourier band shape analysis is applied to obtain the reorientation time correlation functions in the short time limit from the Raman spectra of some ordered nematic liquid crystals. New equations for the simultaneous determination of the static order parameters 〈P2〉 and 〈P4〉, and the tumbling diffusion coefficient D r⊥ are proposed. Their applicability and accuracy are demonstrated by Raman scattering measurements on two prototype aligned mesogens, namely 4, n-pentyl 4′-methoxytolane (PMT) and 4,n-octylethoxytolane (OET). The molecular dynamics in the investigated aligned nematics is also discussed. © 1985 American Institute of Physics.