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High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Competition between local disordering and global ordering fields in nematic liquid crystals
Matej Cvetko1, Milan Ambrozic, Samo Kralj
1Regional Development Agency Mura Ltd, Lendavska 5a, 9000 Murska Sobota, Slovenia, Laboratory of Physics of Complex Systems, Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška 160, 2000 Maribor, Slovenia. Matej.Cvetko@rra-mura.si
Beilstein Journal of Organic Chemistry
|May 27, 2010
Summary
External fields influence liquid crystal ordering in disordered systems. Memory effects in orientational ordering are observed below crossover fields, particularly for random initial configurations.
Area of Science:
- Physics
- Materials Science
- Soft Matter Physics
Background:
- Nematic liquid crystals and rod-like objects exhibit orientational ordering.
- Disorder, such as random anisotropy fields, can significantly impact this ordering.
- External electric or magnetic fields are known to influence liquid crystal behavior.
Purpose of the Study:
- To investigate the effect of external fields (B) on the orientational ordering of nematic liquid crystals and similar systems.
- To analyze the role of random anisotropy field disorder (concentration p, strength W) and system dimensionality (2D, 3D) on ordering.
- To probe memory effects in the system's correlation length (ξ) under varying conditions.
Main Methods:
- Utilizing the Lebwohl-Lasher lattice model, a semi-microscopic approach.
- Performing calculations at zero temperature, ensuring validity below the isotropic phase transition.
- Calculating the correlation function and correlation length (ξ) for different field strengths, disorder concentrations, and dimensionalities.
Main Results:
- Determined the influence of external fields (B) on orientational ordering in the presence of disorder.
- Identified crossover fields (B(c)(p)) that delineate ordered and disordered regimes.
- Observed memory effects in correlation length (ξ) specifically for random initial configurations and fields below B(c).
Conclusions:
- External fields play a crucial role in controlling orientational ordering in disordered liquid crystal systems.
- The presence and strength of disorder, along with system dimensionality, modulate the response to external fields.
- Memory effects are a significant characteristic of these systems under specific field and initial configuration conditions, particularly in the disordered regime.
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