Studies of Molecular Orientation for Ferrielectric Liquid Crystal by Phase Transitions

  • Kim, S.W. (Department of Physics, Korea University) ;
  • Choi, H. (Department of Physics, Korea University) ;
  • Song, J.H. (Department of Physics, Korea University) ;
  • KIm, J.H. (Department of Physics, Kent State University) ;
  • Kumar, S. (Department of Physics, Kent State University) ;
  • Choi, J.W. (Department of Chemistry, College of Science, Kon-Kuk University) ;
  • Kim, Y.B. (Department of Chemistry, College of Science, Kon-Kuk University) ;
  • Shin, S.T. (Department of Physics, Korea University)
  • Published : 2000.01.13

Abstract

We have studied the molecular orientation by the phase transitions of the chiral smectic liquid crystals, 4-(1-Trifluoromethyl-6-ethoxy-hexyloxycarbonlphenyl)-4-nonyloxybiphenyl-4-carbo-xylate (R-TFMEOHPNBC) to seek the original solution of the zig-zag defect using two different experimental techniques; optical system and x-ray scattering. The phase sequence is gamma ferroelectric $(SmC{\gamma}\;^*)$ ${\rightarrow}$ smectic A (SmA) ${\rightarrow}$ isotropic (I). Existence of two layer spacing at chiral smectic phase gives a possibility of the molecular orientation in two different tilt angles, ${\theta}\;_1$ and ${\theta}\;_2$, which are separated each other to the layer normal at a given temperature. The gamma ferroelectric-like phase is, first, discovered in the single compound.

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