Microwave Material Properties of Nanoparticle-Doped Nematic Liquid Crystals
AbstractThis letter presents the material properties of nanoparticle-doped liquid crystal (LC) mixtures at microwave frequencies. A host (undoped) nematic LC material is doped with several concentrations of ferroelectric, gold and silver nanoparticles. The measurements are conducted at 30 GHz by using a cavity perturbation method. Based on these measurements, relative permittivity and dielectric losses are extracted, then the resultant material tunability and figure-of-merit are calculated. Compared to the host LC, some changes in the electrical parameters of the doped samples are observed, reducing the tunability and material figure-of-merit of all samples. Nevertheless, depending on the shape of the nanoparticles, their impact on the material figure-of-merit is more significant than on the tunability, reducing the figure-of-merit drastically once the tunability changed slightly only.