Macroscopic biaxiality and electric-field-induced rotation of the minor director in the nematic phase of a bent-core liquid crystal
Citation:
M. Nagaraj, K. Merkel, J. K. Vij, and A. Kocot, Macroscopic biaxiality and electric-field induced rotation of the minor director in the nematic phase of a bent-core liquid crystal, Europhysics Letters (EPL), 91, 66002, 2010, 1-6Download Item:
Macroscopic biaxiality and electric-field-induced rotation of the minor director in the nematic phase of a bent-core mesogen.pdf (Published (publisher's copy) - Peer Reviewed) 579.3Kb
Abstract:
Biaxiality in the nematic phase has been investigated for the bent-core liquid-crystal para-heptylbenzoate diester, using polarised IR spectroscopy. Anisotropic fluctuations of the nematic director are discussed in terms of the self-assembly of the chiral conformers. The ordering of the minor director for the homeotropicaly aligned sample is found to depend on the rubbing of the substrates of the cell and the amplitude of in-plane electric field. On increasing the in-plane electric field, the rotation of the minor director in the plane of the substrate is observed with an angle of approximately 45?, where initially the minor director is shown to lie along the rubbing direction. It is also shown that on the average the long axis of the molecules is normal to the substrate with surface treatment, with and without rubbing. The electric in-plane field combined with rubbing is shown to induce biaxial order in the nematic phase of a material with negative dielectic anisotropy for the first time.
Sponsor
Grant Number
Science Foundation Ireland (SFI)
07/W.1/I1833
Science Foundation Ireland (SFI)
06/RFP/ENE039
Author's Homepage:
http://people.tcd.ie/jvijDescription:
PUBLISHED
Author: NAGARAJ, MAMATHA; VIJ, JAGDISH
Type of material:
Journal ArticleSeries/Report no:
Europhysics Letters (EPL)91
66002
Availability:
Full text availableKeywords:
Condensed matter physics, BiaxialitySubject (TCD):
Nanoscience & MaterialsLicences: