Computational, dielectric and electro-optical analysis of an orthoconic antiferroelectric mesogen having superstructure in its reduced symmetry phase

Abstract

The study presents a comprehensive analysis of a novel octan-2-yl 4'-(4-{4-[3-(butanoyloxy)propoxy]benzoyloxy}benzoyloxy)-[1,1'-biphenyl]-4-carboxylate (abb. as OAFLC-108), an orthoconic antiferroelectric liquid crystal. Its paramorphic sequence is estimated from defect studies. Its optimised structure, interatomic charge distribution and dynamics, global parameters and nonlinear optical properties are calculated by density functional theory. Vibrational modes are determined experimentally and theoretically. Low-frequency dielectric spectra are studied in view of molecular fluctuations, activation energy and relaxation time. The moderate value (29.5 nC/cm²) of spontaneous polarisation and a response time of 2 ms support the candidature of OAFLC-108 as a competitive optoelectronic material.

Keywords:

• Dielectric relaxation
• liquid crystal
• memory effect
• nonlinear optics
• superstructure
• vibrational spectroscopy

Acknowledgments

The authors would like to thank the Department of Chemistry, NITM for providing the software support.

Additional information

Funding

This work was supported by the Department of Science and Technology, New Delhi, India, under grant no. EMR/2015/002405.