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arXiv · 2605.11413

Landau theory applied to antiferroelectric ordering in ferroelectric nematic liquid crystals

Manisha Badu·Arjun Ghimire·Milon·Priyanka Kumari·Hari Krishna Bisoyi·Oleg D. Lavrentovich·James Gleeson·Antal Jakli·Samuel Sprunt
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Abstract

The polarization and density modulation associated with antiferroelectric ordering is studied experimentally as a function of temperature in two ferroelectric nematic liquid crystals, the prototypical single compound (DIO) and a commercial mixture (FNLC919). The modulation wavenumber qA is determined by small angle X-ray diffraction from the weak smectic-like density wave (wavenumber qS = 2qA) that accompanies the polarization modulation. Results for qS and the saturated value of the polarization are analyzed in terms of Landau theory previously developed to describe the para-/antiferro-/feroelectric sequence of phase transitions in solid ferroelectrics. The analysis indicates that the polarization modulation is reasonably well approximated by a simple sinusoid in the antiferroelectric phase of DIO, whereas in FNLC919 the modulation develops a strongly soliton-like profile (with sharply decreasing wavenumber) close to the antiferro- to ferrolectric transition.

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Manisha Badu, Arjun Ghimire, Milon, Priyanka Kumari, Hari Krishna Bisoyi, Oleg D. Lavrentovich, James Gleeson, Antal Jakli, Samuel Sprunt. 2026-05-12. Landau theory applied to antiferroelectric ordering in ferroelectric nematic liquid crystals. https://arxiv.org/abs/2605.11413

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