DIELECTRIC STUDIES OF LIQUID-CRYSTALS UNDER HIGH-PRESSURE .4. STATIS PERMITTIVITY AND LOW-FREQUENCY RELAXATION PROCESS IN 4-N-HEXYL-4'-CYANOBIPHENYL (6CB)
S. Urban et al., DIELECTRIC STUDIES OF LIQUID-CRYSTALS UNDER HIGH-PRESSURE .4. STATIS PERMITTIVITY AND LOW-FREQUENCY RELAXATION PROCESS IN 4-N-HEXYL-4'-CYANOBIPHENYL (6CB), Liquid crystals, 15(6), 1993, pp. 919-927
Dielectric studies of 4-n-hexyl-4'-cyanobiphenyl (6CB) were performed
in the pressure range 0.1-150 M Pa, the frequency range 1 kHz-13 MHz a
nd the temperature range 290-327 K. The temperature and pressure depen
dencies of the static permittivity epsilon0 parallel-to and the relaxa
tion time tau(parallel-to) are analysed and compared with analogous da
ta obtained recently for 5CB and 6CHBT (parts I-III of this series). I
t was shown that in the nematic phases of both 4-n-alkyl-4'-cyanobiphe
nyls the dipole-dipole correlations are broken by relatively low press
ure.