Critical behaviour of the polarization, tilt angle, electric susceptibility and the specific heat close to the SmA-ferroelectric SmC (SmC*) phase transitions

Yurtseven H., Bellici S., Kilit E.

FERROELECTRICS, vol.344, pp.327-336, 2006 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 344
  • Publication Date: 2006
  • Doi Number: 10.1080/00150190600966888
  • Journal Name: FERROELECTRICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.327-336
  • Middle East Technical University Affiliated: Yes

Abstract

This study gives the temperature dependence of the two order parameters, namely, polarization P and the tilt angle theta, when there is a biquadratic coupling P-2 theta(2) in the expansion of the Landau free energy. This applies to the electric-field-induced SmA-Ferro-Electric SmC (SmC*) phase transition. From this expansion of the Landau free energy in terms of the polarization and the tilt angle, we obtain the temperature dependence of the electric susceptibility chi and the electric field dependence of the polarization P. These dependences of P, theta and chi are fitted to the experimental data for C7 and their critical behaviour in this liquid crystal is described close to the SmA-ferroelectric SmC (SmC*) phase transition.