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Ferroelectric nanoparticles in low refractive index liquid crystals for strong electro-optic response

Malgosia Kaczmarek, Oleksandr Buchnev, Iris Nandhakumar

Applied Physics Letters · 2008 · 85 citations · 14 references

Open access

TL;DR

Ferroelectric nanoparticles in low‑index nematic liquid crystals generate strong induced birefringence and dielectric anisotropy. Atomic force microscopy was used to characterize the shape and size distribution of the ferroelectric nanoparticles. Embedding ferroelectric nanoparticles doubles the birefringence and triples the dielectric anisotropy of the liquid crystal, with Sn₂P₂S₆ nanoparticles delivering a greater electro‑optic boost than BaTiO₃, and the particles averaging 45 nm and 20 nm in diameter, respectively.

Abstract

Functional materials based on ferroelectric, inorganic nanoparticles, and low refractive index nematic liquid crystals show strong induced birefringence and dielectric anisotropy. Birefringence can increase by a factor of 2 and dielectric anisotropy by a factor of 3 as compared with nominally pure liquid crystals. The enhancement of the electro-optic performance is higher in liquid crystals with Sn2P2S6 (SPS) nanoparticles than with BaTiO3 nanoparticles. The shape and size distribution of both types of ferroelectric particles were characterized using atomic force microscopy. The average size of SPS nanoparticles was 45nm and of BaTiO3 nanoparticles was 20nm.