Anomalously high dielectric strength and low frequency dielectric relaxation of a bent-core liquid crystal with a large kink angle

• Published in: Current applied physics Vol. 17; no. 6; pp. 858 - 863
• Main Authors: Srivastava, Anoop Kumar, Kim, Jongyoon, Yeo, Sunggu, Jeong, Jinyoung, Choi, E-Joon, Singh, Vijay, Lee, Ji-Hoon
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2017; 한국물리학회
• Subjects: Bent-core liquid crystal; Dielectric relaxation; Dielectric strength; 물리학; Bent-core liquid crystal; Dielectric strength; Dielectric relaxation
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2017.03.012

We investigated the dielectric dispersion property of a bent-core liquid crystal (BLC) with a large kink angle in the frequency range of 1.0 Hz–5.5 MHz in a planar aligned cell. Single dielectric dispersion was observed in the smectic A, nematic, and isotropic phase of the planar aligned sample. The dielectric strengths, relaxation frequencies, distribution parameters, and dc conductivity were measured as a function of temperature. The dielectric strength of the observed relaxation mode was anomalously high (∼70), whereas the relaxation frequency was low at ∼500 Hz. The relaxation mode observed in the planar aligned cell was attributed to the fluctuations in the polarization direction due to the cooperative motion of the molecules. •Anomalous high dielectric strength and low frequency dielectric relaxation was found in bent-core liquid crystal.•The dielectric strength and the relaxation frequency were measured vs. temperature.•Physical model for the anomalous dielectric response was suggested.