Ferroelectric Nanoparticles in Liquid Crystals: The Role of Ionic Transport at Small Concentrations of the Nanoparticles

• Published in: arXiv.org 2024-11
• Main Authors: Gudenko, Juliya M, Pylypchuk, Oleksandr S, Vainberg, Victor V, Gvozdovskyy, Igor A, Ivanchenko, Serhii E, Stetsenko, Denis O, Morozovsky, Nicholas V, Poroshin, Volodymir N, Eliseev, Eugene A, Morozovska, Anna N
• Format: Article
• Language: English
• Subjects: Barium titanates; Capacitance; Current voltage characteristics; Elastic properties; Ferroelectric materials; Ferroelectricity; Liquid crystals; Nanoparticles
• ISSN: 2331-8422

We reveal the visible influence of the ultra-small concentrations (1 wt.% or less) of the BaTiO3 nanoparticles (average size 24 nm) on the current-voltage characteristics and capacitance of the dielectric liquid crystal (LC) 5CB. The pure LC cell demonstrates higher current (and thus smaller resistance) than the LC cells filled with a very small concentration (0.5-1) wt.% of BTO nanoparticles. The same trend is observed for the charge-voltage characteristics: the capacitance loop is the widest for the pure LC cell and becomes noticeably thinner in the presence of (0.5-1) wt.% of BaTiO3 nanoparticles. This seems counterintuitive, because 1 wt.% of ferroelectric nanoparticles very slightly modify the effective dielectric response and should not influence on the director distribution and elastic properties of the LC. We conclude that a possible physical reason of this observation is the influence of the ionic-electronic screening charges, which cover the ferroelectric nanoparticles and become polarized in the external field, on the ionic transport in the LC.