Strong modulation of electric permittivity at an isotropic-nematic phase transition in a liquid crystal mixture for optical devices based on the Kerr effect

Ferroelectricity in a nematic liquid crystal under a direct current electric field

“…On the one hand, the increase of e 0 can be explained by the formation of dimers. 38 On the other hand, the decrease of the dielectric constant in the highly polar isotropic liquids is related to the formation of quadrupoles. 39 By measuring the spontaneous polarization using the AC signal we show that without the DC field, there is no ferroelectricity in the nematic phase.…”

“…On the one hand, the increase of ε′ can be explained by the formation of dimers. 38 On the other hand, the decrease of the dielectric constant in the highly polar isotropic liquids is related to the formation of quadrupoles. 39…”

Threshold voltage decrease in a thermotropic nematic liquid crystal doped with graphene oxide flakes

“…During the cooling process, at the phase transition temperature T I-N , the transmission of light starts to increase due to the nucleation of the nematic phase (bright state). In the experiment, the clearing temperature of the pure 5CB (33.0 °C) was 2 °C below that of previous reports [34,36]. The effect of the lower T I-N is related to the strong boundary conditions of the thin cell.…”

“…It is a room temperature nematic liquid crystal material of high chemical stability. The phase transition from the isotropic phase to the nematic phase and then to the crystalline phase is at 35 °C and 18 °C, respectively [34–36]. Pentylcyanobiphenyl (5CB) has a large longitudinal (µ || ) electric dipole moment, which equals 6.37 D, while the transverse component () is 0.15 D [36].…”

“…The phase transition from the isotropic phase to the nematic phase and then to the crystalline phase is at 35 °C and 18 °C, respectively [34–36]. Pentylcyanobiphenyl (5CB) has a large longitudinal (µ || ) electric dipole moment, which equals 6.37 D, while the transverse component () is 0.15 D [36]. Hence, the material shows a relatively large positive electric anisotropy Δε (Δε ≈ 12 at 1 kHz and 25 °C) [34,36–37].…”