Paper
12 September 2013 Properties of the self-deforming Ntb phase in mesogenic dimers
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Abstract
An overview of the results obtained from the most recent experiments performed for revealing the structure of the twistbend nematic Ntb phase will be presented at the conference. This new phase provides typical X-ray diffraction pattern for the nematic phase and is found at temperatures below the conventional nematic phase in odd-chain hydrocarbon linked mesogenic dimers. The materials in the Ntb phase form self-deformed striped pattern parallel to the rubbing direction in planarly aligned rubbed cells with a well-defined period. The period is found to depend on the cell spacing. The selfdeformation stripes appear without any external electromagnetic field or thickness gradient across the cell. Although the materials are composed of non-chiral molecules, the low temperature nematic phase exhibits fast linear optical response of the order of a few microseconds. This response is reminiscent of the phase exhibiting chirality. Moreover, at higher fields some of the materials form striped domains with opposite direction of the optical response. These stripes appear normal to the rubbing direction and their periodicity depends on voltage and frequency. The Freedericksz transition in this phase also shows unusual properties and this is proven to be of the first order. The techniques to characterize this phase include polarized microscopy observation and optical contrast spectroscopy. Possible causes of the phenomena will be discussed.
© (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Vitaly P. Panov, Jagdish K. Vij, Reshma Balachandran, Volodymyr Borshch, Oleg D. Lavrentovich, Maria G. Tamba, and Georg H. Mehl "Properties of the self-deforming Ntb phase in mesogenic dimers", Proc. SPIE 8828, Liquid Crystals XVII, 88280X (12 September 2013); https://doi.org/10.1117/12.2024470
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Cited by 12 scholarly publications.
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KEYWORDS
Switching

Polarizers

Anisotropy

Dielectrics

Liquid crystals

Molecules

Microscopes

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