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      https://www.ias.ac.in/article/fulltext/pram/052/04/0443-0451

    • Keywords

       

      Ferroelectric liquid crystal; dielectric increment; relaxation mode; Goldstone mode; soft mode

    • Abstract

       

      The dielectric measurements in SmC* and SmA phases of a room temperature ferroelectric liquid crystal mixture FLC-6980 in the cells of different thickness in planer alignment have been carried out in the frequency range 100 Hz to 1 MHz. A relaxation mode (called NRM) whose dielectric increment is less than the Goldstone mode has been observed in the SmC* phase. This mode appears due to the surface effect. Goldstone mode and the soft mode was observable in the vicinity of SmC*-SmA transition temperature (TC*A). The dielectric parameters of the Goldstone mode, new mode and the soft mode have been studied as a function of frequency and temperature. The calculated values for fNRM, δεNRM and distribution parameter αNRM are found to be 325 kHz, 6 and 0.156 for 5μm thick planer cell at 37°C. It is seen that in the vicinity of theTC*A, soft mode obeys the Curie-Weiss law given by mean field theory. The results have been compared with materials of large spontaneous polarization.

    • Author Affiliations

       

      K K Raina1 Arvind K Gathania2 Buta Singh2

      1. School of Basic and Applied Sciences, Thapar Institute of Engineering and Technology, Patiala - 147 004, India
      2. Department of Physics, Punjabi University, Patiala - 147 002, India
    • Dates

       
  • Pramana – Journal of Physics | News

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