抄録
Polarized Raman measurement can determine not only the second but also the fourth order parameters of Raman tensor of local molecular structure in partial oriented system like liquid crystal phase. We have determined the second and the fourth order parameters, P2 and P4 of several homogeneous oriented liquid crystals. Polarized Raman scattering has been measured as a function of the incident laser polarization and the order parameters have been determined by taking account of retardation. This procedure turned out to be more accurate than the previous methods. For 5CB with 50 μm thickness P2 and P4 of ciano group are 0.52 and 0.02, those of phenyl group are 0.52 and 0.12 at 25℃. This result suggests that distributions of phenyl and ciano groups are almost the same and the core part of molecule is rigid. For other liquid crystals the order parameters were determined and ordering of local structures will be also discussed.
