Effect of External Fields on the Condensation of a Biaxial Nematic Liquid Crystal phase with Significant Coupling between Uniaxial and Biaxial Orders

Jose, Regina and B, Kamala Latha and K. P. N, Murthy and V. S. S, Sastry (2015) Effect of External Fields on the Condensation of a Biaxial Nematic Liquid Crystal phase with Significant Coupling between Uniaxial and Biaxial Orders. In: National Conference on Current Trends in Soft Matter, 19-20 March, 2015, Thiruvarur.

[img]
Preview
PDF
Effect of External Fields on the Condensation of a Biaxial Nematic Liquid Crystal phase with Significant Coupling between Uniaxial and Biaxial Orders_NCCTSM_2015.pdf

Download (267kB) | Preview
Official URL: http://cutn.ac.in/ncctsm/

Abstract

Hamiltonian model describing general quadratic interactions among liquid crystal molecules (with positive dielectric anisotropy, and D2h symmetry) is investigated in the presence of an external field Ea (coupling to their long axes), through Monte Carlo simulations. While the isotropic-to-uniaxial nematic (I-NU) transition temperature is enhanced with increasing field (attributed as due to the quenching of the primary director), the uniaxial-to-biaxial nematic transition on the other hand, seemingly concurrent with I-NU transition at Ea =0, is split, and occurs at progressively low temperatures with increasing field. By comparing our recent detailed investigations on this (zero-field) transition via a sampling procedure facilitating the computation of the density of states of the system [Latha et. al., Phys. Rev. E, 89 050501(R) (2014)], we infer that the applied field is effectively decreasing the degree of the mesoscopic inhomogeneity of the medium (with respect to the distribution of the orientational order), induced by the cross-coupling interactions among molecular tensor components. We argue that this facilitates an increasingly more evident role of the biaxial-biaxial tensor interactions among neighbours, so as to induce a condensation of a macroscopically biaxial medium at a lower temperature. These observations perhaps suggest that within this model, application of an appropriate external field might be effectively equivalent to a virtual shift of the system point (in the two-dimensional parameter space of the Hamiltonian) to facilitate possibly a ready condensation of the system into a biaxial phase.

Item Type: Conference or Workshop Item (Paper)
Uncontrolled Keywords: Biaxial nematic, Monte Carlo.
Subjects: Departments at MU > Manipal Centre for Natural Sciences
Depositing User: MCNS Editor
Date Deposited: 04 Apr 2015 05:11
Last Modified: 04 Apr 2015 05:11
URI: http://eprints.manipal.edu/id/eprint/142332

Actions (login required)

View Item View Item