Temperature dependence of Raman scattering from monocrystalline terephtal-bis-butyl-aniline (TBBA): Low-frequency spectra

Raman spectroscopy gives us a very useful tool for studying the vibrational dynamics of liquid crystals and, in particular, their structural phase changes. In order to investigate lattice mode nature of the structure sensitive low- and very low-frequency intermolecular modes of TBBA (terephtal-bis-butyl-aniline), we have studied the polarized Raman spectra from oriented monocrystals, and have followed the temperature dependence of such spectra from 90 to 300^∘{}K. The reported results are interpreted on the basis of a proposed dynamical model involving rotational Brownian motions in the crystalline phases.