Dielectric and Electrical Investigations in Pure and Dyed Short Pitch High Spontaneous Polarization Liquid Crystals

Abstract

The dielectric and electrical properties of a short pitch and high spontaneous polarization ferroelectric liquid crystal mixture and its guest–host derivatives with different wt/wt ratio of anthraquinone blue dichroic dye are studied. The increase in dye concentration results in the decrease of the permittivity as well as polarization of the material in the SmC* phase. However, an opposite effect is observed in permittivity, in the SmA* phase, and in polarization near the T _C . The response time of pure material is found to be less than the dyed samples with no appreciable change in viscosity.

Keywords:

• Anthraquinone dye
• dielectric strength
• ferroelectric liquid crystals
• guest-host mixtures
• relaxation frequency

Acknowledgments

The author thanks Dr. M. Schadt (Rolic, Switzerland) and M/s BDH (UK) for providing the liquid-crystal material and CLU 437730 dye, respectively. The financial support from the Department of Science and Technology, Government of India, is gratefully acknowledged. The author also thanks the referee for his valuable suggestions that helped in strengthening our theoretical model.