Molecular director and layer response of chevron surface stabilized ferroelectric liquid crystals to low electric field

Correlation between static and dynamic polarimetric properties and the texture of surface-stabilised ferroelectric liquid crystal cells

“…This behavior has already been proposed by other teams and compared with optical intensity measurements [21][22]. However, according to the experiments reported in [15] and [23], no reversible smectic layer movement upon field reversal was observed. It was suggested in [15] that the smectic layers remains unchanged and that the in-depth distribution of the molecules is quasi-uniform.…”

“…Such a behavior cannot result in the observation of a flat-shaped trajectory for the OA uuu r vector. In [23], the authors proposed the formation of half-splayed states during switching. However, such a distribution would generate a high ellipticity parameter ε R (see Section 3), that was never observed in this study, whatever the experiment (Figure 10).…”

Local layer structure of the steep field line defect in surface-stabilized ferroelectric liquid crystal cells

“…Three zig-zag tip features favour field line nucleation there: (i) layers within the zig-zag tip are highly kinked, hence vulnerable to degradation; (ii) zig-zag walls contain flattened smectic layers rotated slightly in 1, similar to the field line internal structure, and (iii) they also probably contain high densities of edge dislocations. The last point is drawn from other X-ray scattering experiments [14], which have shown that edge dislocations are present in the surface stabilized ferroelectric liquid crystal cell, and consideration of the chevron formation process, which we expect drives these dislocations into the zig-zag walls.…”

“…Regarding the field line defect's growth, a chevroned surface stabilized ferroelectric liquid crystal cell has at least a two step response to any applied field E. In the first response, at low applied fields, the molecules progressively rotate about their individual imaginary tilt cones [14]. This reduces the angle between P and E to about 6, the layer tilt angle.…”

Dynamic analysis of chevron structures in liquid crystal cells

“…Just how robust this regeneration is remains an open question. This is an important point since the studies of Willis et al [21] showed that there should be no significant change in smectic layer thickness or chevron layer structure under typical director switching conditions.…”