Dielectric Dynamics and Polar Nanoregions in Ferroelectric Nematic Liquid Crystals of the nJK Series
4 affiliations
- 1Institute of Materials Engineering, Faculty of Science and Technology
- 2University of Silesia
- 3Institute of Chemistry, Faculty of Advanced Technologies and Chemistry
- 4Military University of Technology
Abstract
This study presents a comprehensive investigation of polarization dynamics and phase transitions in a novel homologous series of polar nematics (nJK, n=1-5) using broadband dielectric spectroscopy (DS). The analysis of dielectric spectra in planar and homeotropic cells revealed the evolution of relaxation mechanisms, transitioning from single-particle molecular reorientations in the isotropic phase to complex collective dynamics across the nematic (N), intermediate (N X ), and ferroelectric nematic (N F ) phases. Critical soft-mode behavior was observed near the N F transition for both the longitudinal mode (m1, acting as an amplitude mode) and the high-frequency mode (m3, exhibiting phason-like characteristics), indicating strong coupling between molecular dipoles and splay fluctuations. Furthermore, fitting the dielectric permittivity to a modified Curie–Weiss law reveals a broad temperature range of relaxor-like behavior above T c, characterized by diffuseness exponents γ ≈1.6 for ferroelectric members ( 3JK,4JK). This confirms the formation of Polar Nanoregions (PNRs) stabilized by lateral shifted molecular arrangements in the high-temperature nematic liquid, establishing a nematic relaxor ferroelectric (nRFE) state spanning almost the entire N phase window.
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BibTeX
@misc{janik2026dielectric,
title = {{Dielectric Dynamics and Polar Nanoregions in Ferroelectric Nematic Liquid Crystals of the nJK Series}},
author = {Aleksander Janik and Bartosz Nikiel and Jakub Karcz and Przemysław Kula and Antoni Kocot},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010997/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010997/v1},
note = {CC BY-NC},
}
RIS
TY - UNPB
TI - Dielectric Dynamics and Polar Nanoregions in Ferroelectric Nematic Liquid Crystals of the nJK Series
AU - Aleksander Janik
AU - Bartosz Nikiel
AU - Jakub Karcz
AU - Przemysław Kula
AU - Antoni Kocot
PY - 2026
DA - 2026/10/25
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010997/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010997/v1
AB - This study presents a comprehensive investigation of polarization dynamics and phase transitions in a novel homologous series of polar nematics (nJK, n=1-5) using broadband dielectric spectroscopy (DS). The analysis of dielectric spectra in planar and homeotropic cells revealed the evolution of relaxation mechanisms, transitioning from single-particle molecular reorientations in the isotropic phase to complex collective dynamics across the nematic (N), intermediate (N X ), and ferroelectric nematic (N F ) phases. Critical soft-mode behavior was observed near the N F transition for both the longitudinal mode (m1, acting as an amplitude mode) and the high-frequency mode (m3, exhibiting phason-like characteristics), indicating strong coupling between molecular dipoles and splay fluctuations. Furthermore, fitting the dielectric permittivity to a modified Curie–Weiss law reveals a broad temperature range of relaxor-like behavior above T c, characterized by diffuseness exponents γ ≈1.6 for ferroelectric members ( 3JK,4JK). This confirms the formation of Polar Nanoregions (PNRs) stabilized by lateral shifted molecular arrangements in the high-temperature nematic liquid, establishing a nematic relaxor ferroelectric (nRFE) state spanning almost the entire N phase window.
ER -