Audio frequency dielectric response of the liquid-crystal ce8 in chiral and racemic forms

The real and imaginary parts of the dielectric function of racemic and chiral CE8 have been measured between 30 Hz and 13 MHz at temperatures between 51 and 162 °C. Low- (1 kHz) and high-(10⁵ Hz) frequency dielectric constants reflect changes in structure of the liquid-crystal phases and differences in behavior of the two forms. The low-frequency relaxation in the ferroelectric SmC* phase, near 1500 Hz, was studied in detail as a function of temperature and dc bias. The mean relaxation time does not present an obvious systematic variation with temperature although the low-frequency dielectric constant and distribution of relaxation times do. The mean relaxation time in the SmC* phase shifts continuously to shorter times with the application of dc bias.