Dielectric Properties of Compounds Creating Dual-Frequency Nematic Liquid Crystals |
| M. Mrukiewicza, P. Perkowskia, K. Garbatb, R. Dąbrowskib and J. Parkaa
aInstitute of Applied Physics, Military University of Technology, S. Kaliskiego 2, 00-908 Warsaw, Poland b Institute of Chemistry, Military University of Technology, S. Kaliskiego 2, 00-908 Warsaw, Poland |
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| In this paper we report how dielectric spectroscopy can help in creating of dual-frequency nematic liquid crystals. Dual-frequency nematic liquid crystals is new class of liquid crystal materials. Such mixture is usually formed by a combination of many components (even more than 10), which can be split into two groups: molecules having large transverse dipole moment and molecules with a large longitudinal dipole moment. The behavior of a base (parent) mixture, functional admixtures and final dual-frequency nematic liquid crystals mixture is investigated by dielectric spectroscopy in wide frequency (100 Hz-10 MHz) and temperature ranges. This allows us to find out why the dual-frequency liquid crystal has an important feature: positive and negative dielectric anisotropy at different frequencies. We present parameters of molecular motions around short (S-mode) and long (L-mode) molecular axes observed in investigated materials and discuss how the creation of final dual-frequency nematic liquid crystals mixture can modify molecular relaxations. |
DOI: 10.12693/APhysPolA.124.940 PACS numbers: 77.22.Gm, 77.84.Nh, 61.30.-v |