Publication Title
Physical Review E
Publication Date
3-2009
Document Type
Article
Keywords
electric field effects, electro-optical effects, liquid crystal phase transformations, nematic liquid crystals, texture
Disciplines
Physics
Abstract
We propose that, for materials having positive dielectric anisotropy, the biaxiality can be clearly verified or excluded by measuring the transmitted light intensity as a function of electric field. If the material is biaxial and is observed in homeotropically aligned cells, the schlieren texture should not disappear (transmitted intensity is not zero) even at very high fields, since the field does not affect the distribution of the second director normal to the main director. On the other hand, if the material is uniaxial the transmitted intensity should decrease with increasing field and a perfect homeotropic texture can be achieved at high fields. We have studied a bent-core compound in which a uniaxial-biaxial nematic (N(u)-N(b)) transition has been reported. This material has a positive dielectric anisotropy at low frequencies, so we could apply the technique described above. Our studies indicate that the material is uniaxial in the entire nematic range.
Recommended Citation
Le, Khoa Van; Mathews, Manoj; Chambers, Martin; Harden, John; Li, Quan; Takezoe, Hideo; and Jákli, Antal (2009). Electro-Optic Technique to Study Biaxiality of Liquid Crystals with Positive Dielectric Anisotropy: The Case of a Bent-Core Material. Physical Review E 79(3). Retrieved from https://digitalcommons.kent.edu/cpippubs/61
Comments
Copyright 2009 American Physical Society. Available on publisher's site at http://dx.doi.org/10.1103/PhysRevE.79.030701.