Dynamic local-layer response of surface-stabilized ferroelectric liquid crystals to a high electric field by time-resolved x-ray microdiffraction

Transitional subphases near the electric-field-induced phase transition to the ferroelectric phase in Se-containing chiral smectic liquid crystals observed by resonant x-ray scattering

Resonant x-ray scattering experiments revealed transitional subphases near the electric-field-induced phase transition of a Se-containing chiral liquid crystal in a planar aligned cell geometry. In the lower-temperature range (Sm-C_{A}^{*} and three-layer periodicity Sm-C_{γ}^{*} phases), the six-layer periodicity subphase appeared with increasing electric field during the field-induced transition from Sm-C_{γ}^{*} to Sm-C^{*}. In the higher-temperature range [four-layer periodicity antiferroelectric (AF) phase], the peak positions of the three-layer satellites shifted to those of the four-layer satellites and then the satellites corresponding to the five- through seven-layer periodicity appeared in sequence. Near the AF to Sm-C_{α}^{*} phase transition temperature, the layer periodicity increased with applied field. The molecular configurations of the subphases near the field-induced transition are discussed based on the Ising, distorted clock, and perfect clock models.

Impact of the concentration in polymer on the dynamic behavior of Polymer Stabilized Ferroelectric Liquid Crystal using Snap-shot Mueller Matrix Polarimetry

Experimental results are presented related to the dynamic behaviour of Polymer Stabilized Ferro-electric Liquid Crystal (PSFLC) samples under external applied electric field, using Snap-shot Mueller Matrix Polarimetry (SMMP) and Mueller Matrix (MM) formalism. Different polarimetric coefficients are simultaneously extracted from each channeled spectrum measured with this full-optical SMMP technique. The impact of the concentration of polymer present into the liquid crystal cell on this dynamic behaviour is studied, permitting a direct and quick characterisation of the material. The results obtained for PSFLC are compared with those already measured for pure Surface Stabilized Ferro-electric Liquid Crystal (SSFLC) samples, which correspond to a 0% concentration in polymer.

Electric-field-induced transition between the polarization-modulated and ferroelectric smectic- C(S) P(F)* liquid crystalline states studied using microbeam x-ray diffraction

We report x-ray microbeam studies of a bent-core liquid crystalline material with chiral citronellyl tails. This material has an equilibrium polarization-modulated smectic- CP (PM-SmCP) state exhibiting the B7 texture upon slow cooing from the isotropic while a metastable chiral synclinic ferroelectric Sm-CP state (Sm- C(S) P(*)(F) ) is obtained on quenching from the isotropic. The polarization modulated phase PM-Sm C(S) P(*)(F) shows typical x-ray patterns having multiple satellite peaks around the first-order layer reflection, indicating undulated layers, while the metastable Sm- C(S) P(*)(F) state exhibits a single layering peak indicating flat layers. The Sm- C(S) P(*)(F) state is also induced by the application of an electric field larger than the threshold field ( E(th) ) and thermally returns to the polarization modulated PM-Sm C(S) P(*)(F) structure.