Exploration of Goldstone mode and field-induced SmA-SmC*-SmC Lifshitz point in chiral liquid crystal dimers for multiple polarization switching

SmC* phase structure and its device utility reviewed. Diversity for transverse dipole moment of chiral centre and collective modes in hydrogen bonded calamitic liquid crystal dimer, viz. nOBA:M*SA:nOBA for n = 12 investigated. Multiple polarization switching of Goldstone mode GM for greyscale envisaged in tilted SmC* phase. A simple low-frequency relaxation method to determine pitch lambda of polarization helix for SmC* GM in SmC* phase by dielectric loss peak epsilon(max)''. Qualitative analogy between lambda and reciprocal 1/Delta epsilon(max-GM)'' of GM dielectric loss maximum derived. Ferroelectric characterization, i.e. by hysteresis, growth of tilt angle and spontaneous polarization as order parameters, electro-clinic effect, collective excitations, relaxations and Curie-Weiss law presented. Field-induced loss [1/Delta epsilon(max-GM)''] reflected the field diverging trend of helical pitch of polarization in SmC*. Collective response and relaxations analysed by the Cole-Davidson method. Goldstone and soft mode are resolved by field. Field study of loss inferred second-order nature C*-C transition. Lifshitz Point results agree with T-H plane reports. AC*C LP demarcated in T-E plane. Second-order A-C, first-order A-C* and second-order GC* transition lines converge at LP to agree with extended Landau-Ginzburg model. Design of space graded conductive-coated surface stabilized ferroelectric liquid crystal cell for multiple polarization switching modes and greyscale proposed.