Dielectric properties of bent-core and calamitic liquid crystal mixtures

Peter Salamon ,Nandor Eber ,Agnes Buka ,James T. Gleeson ,Samuel Sprunt ,Antal Jakli 2

Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, H-1525 Budapest, P.O.B. 49, Hungary
Department of Physics, Kent State University, Kent, OH 44242, USA
2Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA

Dielectric spectroscopy measurements have been performed on a bent-core nematic liquid crystal and on its binary mixtures with a calamitic nematic. We have detected more dispersions in the bent-core compound than in the calamitic one, including one at an unusually low frequency of a few kHz. The dispersions detected in the mixtures have been identified and the spectra have been split into contributions of the constituents. In order to connect the dielectric increment with the molecular dipole moment we have applied a sophisticated conformational calculation not performed before for a large, flexible mesogen molecule with numerous polar groups.

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