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High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
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Periodic structures on liquid-phase smectic A, nematic and isotropic free surfaces
Anna N Bagdinova1, Evgeny I Demikhov1, Nataliya G Borisenko2
1Cryogenic department, P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow, 119991, Russia.
Beilstein Journal of Nanotechnology
|March 9, 2018
Summary
Researchers discovered a new periodic stripe structure on liquid crystal surfaces using advanced microscopy. This finding, observed across smectic A, nematic, and isotropic phases, may be explained by nonlinear electrostatic instabilities.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Physical Chemistry
Background:
- Liquid crystals exhibit diverse phase behaviors and surface phenomena.
- Understanding the free boundaries of liquid crystal phases is crucial for their applications.
Purpose of the Study:
- To investigate the free boundary structures of smectic A (SmA), nematic, and isotropic liquid crystal phases.
- To characterize a newly observed periodic stripe structure on these surfaces.
Main Methods:
- Utilized polarized optical microscopy, interferometric surface structure analyzer (ISSA), atomic force microscopy (AFM), and scanning near-field optical microscopy (SNOM).
- Correlated surface images obtained from different microscopy techniques.
Main Results:
- Observed a well-known focal domain structure on the SmA phase free surface using polarized microscopy and ISSA.
- Discovered a novel periodic stripe structure on the surfaces of SmA, nematic, and isotropic liquid crystal phases via SNOM.
- Properties of the periodic stripe structure resemble those of charged liquid helium surfaces.
Conclusions:
- The newly observed periodic stripe structure can be attributed to nonlinear electrostatic instabilities.
- This finding offers new insights into the surface physics of liquid crystals.
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