Broadband dielectric spectroscopy on ferroelectric liquid crystalline polymers
暂无分享,去创建一个
The collective and molecular dynamics of ferroelectric liquid crystalline side group polysiloxanes has been investigated for use of broadband dielectric spectroscopy (10-2 Hz - 109 Hz). In the lower frequency range (< 106 Hz) two collective relaxations, Goldstone- and soft-mode, could be observed. They are assigned to the fluctuations of the phase and the amplitude of the helical superstructure, respectively. In the high frequency regime (106 Hz - 109 Hz) one dielectric relaxation, the (beta) - relaxation, is found. It is assigned to the hindered rotation (libration) of the mesogene around its long molecular axis. It shows an Arrhenius-like temperature dependence with no deviations at the phase transition SA/S*C. A dilution of the mesogenes causes a decrease of the collectivity but remains the local dynamics uninfluenced.