Light Scattering Study of Biaxiality in Nematic Liquid Crystal Tetrapodes

ORAL

Abstract

We have performed dynamic light scattering studies on thermotropic liquid crystalline tetrapodes [1], which reportedly exhibit a uniaxial to biaxial nematic phase transition. Our results [2] support the existence of the biaxial nematic phase in tetrapodes. The uni - to biaxial transition is found to be weakly first-order in a 4-ring tetrapode and second-order in a 3-ring tetrapode, while the isotropic to uniaxial nematic transition is weakly first order in both materials. The temperature dependence of the relaxation rates of the biaxial order parameter modes, and of the intensity associated with biaxial director fluctuations, is explained by a Landau-deGennes model of the free energy. \newline [1] R. Elsasser, J. W. Goodby, G. H. Mehl, D. Rodriguez-Martin, R. M. Richardson, D. J. Photinos, and M. Veith, Mol. Cryst. Liq. Cryst. \textbf{402}, 237 (2003) \newline [2] K. Neupane, S. W. Kang, S. Sharma, D. Carney, T. Meyer, G. H. Mehl, D. W. Allender, S. Kumar, and S. Sprunt, \textit{Phys. Rev. Lett.} \textbf{97}, 207802 (2006)

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Authors

  • Krishna Neupane

    • Department of Physics, Kent State University

  • Shinwoong Kang

    • Department of Physics, Kent State University

  • Sunil Sharma

    • Department of Physics, Kent State University

  • D. Carney

    • Department of Physics, Kent State University

  • T. Meyer

    • Department of Physics, Kent State University

  • George H. Mehl

    • Department of Physics, Kent State University

  • David W. Allender

    • Department of Physics, Kent State University

  • Satyendra Kumar

    • Department of Physics, Kent State University

  • Samuel Sprunt

    • Department of Physics, Kent State University