Crystal to Liquid-Crystal Transition Studied by Raman Scattering

Phase transitions of the nematic liquid crystal $p$-methoxy-benzylidine, $p-n$ butyl-aniline were studied by recording the low-frequency Raman spectrum. The intensity of the lattice Raman bands undergoes abrupt change at the crystalline-to-nematic phase transition temperature, with an indication of a hysteresis. The band totally disappears at the isotropic (liquid) phase.