Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 27th March 2019 from 11:00 AM to 1:00 PM (GMT).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 4, 2012
Previous Article Next Article

Patterned flexoelectric instability in a bent-core nematic liquid crystal

Author affiliations

Abstract

We examine here the Bobylev–Pikin flexoelectric instability in an initially planar monodomain of a bent-core nematic liquid crystal, which is negative in conductivity and dielectric anisotropies. Experiments employing dc excitation reveal the domain density to be linear in field, as predicted; however, the instability threshold has a negative temperature coefficient indicating the effective flexomodulus as nonquadratic in order parameter. The dc threshold is also determined as a function of simultaneously acting ac voltage; a theoretical fit is found for the data taking into account elastic anisotropy, whereby the relevant flexoelectric and elastic parameters are estimated. Remarkable morphological changes occur under an increasing field. Half-strength disclinations of opposite topological charge evolve within the flexostructure rendering the wavevector orientation degenerate in the layer plane. Dipolar and quadrupolar topological defect patterns, akin to the singularities in cholesteric fingerprint texture, lead finally to fan like objects. The morphological equivalence between the periodic flexoelectric state and a layered lattice as realized here is attributable to a much lower energy of bend type distortion compared to splay, unlike in a calamitic.

Graphical abstract: Patterned flexoelectric instability in a bent-core nematic liquid crystal

Back to tab navigation

Publication details

The article was received on 30 Sep 2011, accepted on 26 Oct 2011 and first published on 28 Nov 2011


Article type: Paper
DOI: 10.1039/C1SM06870A
Citation: Soft Matter, 2012,8, 1202-1214

  •   Request permissions

    Patterned flexoelectric instability in a bent-core nematic liquid crystal

    P. Tadapatri, K. S. Krishnamurthy and W. Weissflog, Soft Matter, 2012, 8, 1202
    DOI: 10.1039/C1SM06870A

Search articles by author

Spotlight

Advertisements