Double-peak polarization current response in the unusual SmA* phase of a fluorinated high-tilt antiferroelectric liquid crystal

作者：Ghosh S^*; Nayek P; Roy S K; Majumder T Pal; Zurowska M; Dabrowski R

来源：EPL, 2010, 89(1): 16001.

DOI：10.1209/0295-5075/89/16001

A detailed investigation of the dielectric, electro-optical properties and X-ray studies have been made in the vicinity of the transition from Smectic-A* to Smectic-C* as well as in the Smectic-A* phase of a newly synthesized partially fluorinated high-tilt antiferroelectric liquid crystal (AFLC) material. The Smectic-A* phase of this material exhibits high optical tilt, minimum layer shrinkage from paraelectric-to-ferroelectric phase transition and unusual dielectric behavior, which are the complementary evidences that the Smectic-A* phase is of de Vries type. Double-peak polarization current response and tristable-optical-switching studies have revealed an antiferroelectric molecular ordering in the de Vries SmA* phase of this material. Two distinct dielectric relaxation peaks in the SmA* phase also complement the antiferroelectric-like ordering of the molecule in the SmA* phase. The material undergoes a first-order SmA*-SmC* transition which is confirmed by a high enthalpy change and the discontinuity of the dielectric parameters at the phase transition.

• 出版日期2010-1