Knowledge Bank

Phase transitions in molecular solids and liquid crystals have been investigated by Brillouin scattering and correlation spectroscopy. Results for benzil and a lyotropic liquid crystal (Na decyl sulfate-decanol-$Na2SO4-H2O$) will be presented. For benzil two soft modes have been observed in the trigonal high temperature phase. Correlation data are also obtained which show a critical anomaly. In the liquid crystal critical anomalies have been observed for relaxation times at 10,42, $46\circ$C.