Frequency modulation response of a tunable birefringent mode nematic liquid crystal electrooptic device fabricated by doping nanoparticles of Pd covered with liquid-crystal molecules

We fabricated a tunable birefringent (TB) mode nematic liquid-crystal (NLC) electrooptic device using NLC-K15 (Merck) as a host NLC (called NLG-1), where the cell is doped with Pd nanoparticles covered with NLC (NLC-2) molecules, having a cyano group such as 5CB (Merck) with positive dielectric anisotropy (Deltaepsilon > 0) or CCN-47 (Merck) with negative Deltaepsilon (Deltaepsilon < 0). The diameter of the core Pd particle is 2.5 nm and the concentration of nanoparticles is 1 wt%. The TB mode LCD cell fabricated in this way exhibits a remarkable frequency modulation response below 100 Hz of the driving voltage waveform. It is considered that the frequency modulation (FM) response of the TB-NLCD may be attributed to Maxwell-Wagner type interfacial polarization between the host NLC medium and doped nanoparticles.