Flexoelectricity and competition of time scales in electroconvection

Tibor Tóth-Katona, Nándor Iber, Ágnes Buka, Alexei Krekhov

Research output: Article

22 Citations (Scopus)

Abstract

An unexpected type of behavior in electroconvection (EC) has been detected in nematic liquid crystals (NLCs) under the condition of comparable time scales of the director relaxation and the period of the driving ac voltage. The studied NLCs exhibit standard EC (s-EC) at the onset of the instability, except one compound in which nonstandard EC (ns-EC) has been detected. In the relevant frequency region, the threshold voltage for conductive s-EC bends down considerably, while for dielectric s-EC it bends up strongly with the decrease of the driving frequency. We show that inclusion of the flexoelectric effect into the theoretical description of conductive s-EC leads to quantitative agreement, while for dielectric s-EC a qualitative agreement is achieved. The frequency dependence of the threshold voltage for ns-EC strongly resembles that of the dielectric s-EC.

Original languageEnglish
Article number036306
JournalPhysical Review E - Statistical, Nonlinear, and Soft Matter Physics
Volume78
Issue number3
DOIs
Publication statusPublished - szept. 8 2008

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ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Condensed Matter Physics

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