Dielectric study of collective and molecular dynamics in a glass-forming low molecular mass ferroelectric liquid crystal and its racemic mixture

The dynamics of a low molecular mass ferroelectric liquid crystal that can be frozen into a glassy state has been studied by means of broadband dielectric spectroscopy covering a wide time scale range from 10(-10) to 10 s. Both the optically active compound and the racemic mixture have been studied. The temperature dependence of the relaxation frequency of the Goldstone mode, related to azimuthal fluctuations of the director, follows the Vogel-Fulcher-Tammann law. The frequencies of the modes associated with the overall motions of the molecules also show this behaviour. A high frequency Arrhenius-like mechanism was also observed.