Phase behavior in the reentrant-nematic region of chiral frustrated smectic liquid crystals

نویسندگان

  • G. S. Iannacchione
  • C. W. Garland
  • E. Gorecka
چکیده

A high-resolution ac calorimetric study has been carried out on two homologous polar liquid crystals with aromatic cores containing three phenyl groups and a flexible chiral linking group. The expected smectic polymorphism occurs, and there are several prominent thermal features in the nematic range between smecticAd and smectic-C̃ phases. It is suggested on the basis of characteristic thermal signatures, helical pitch variations, and optical textures that a twist-grain-boundary phase and chiral line liquids (NL*) exist as well as twisted nematic liquid crystals (N*) with other kinds of short-range order. @S1063-651X~98!03607-1#

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تاریخ انتشار 1998