Theoretical investigation of antiferroelectric (SmCA⁎) subphases by hydrodynamical approach

Abstract We provide a hydrodynamical approach utilizing time dependent Landau–Ginzburg model (L–G) and the Cahn–Hilliard model (C–H) to investigate antiferroelectric liquid crystals (AFLCs) exhibiting different chiral phases between paraelectric smectic A (SmA ⁎ ) phase and antiferroelectric smectic C A ⁎ phase (SmC A ⁎ ). Introducing conserved and non-conserved order parameters in C–H and L–G models, we have predicted the appearance of a chiral smectic C (SmC ⁎ ) phase and a ferrielectric SmC FI1 ⁎ phase (three layers SmC A ⁎ ) in an antiferroelectric phase sequence. The three layers periodicity for SmC FI1 ⁎ phase is studied in detail with a non-uniform layer interactions among smectic layers with strong experimental support. Finally, we provide some theoretical basis for the non-uniformity of our proposed layer interactions.