The ferroelectric nematic phase: an optimum liquid crystal candidate for nonlinear optics

The effect of a lateral alkyloxy chain on the ferroelectric nematic phase

“…Indeed, the N F phase is arguably the hottest topic in the science and technology of liquid crystals, elevating Born’s work from the status of a footnote. 8–23…”

“…Indeed, the N F phase is arguably the hottest topic in the science and technology of liquid crystals, elevating Born's work from the status of a footnote. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Presently there are relatively few molecules known to exhibit the N F phase, but these appear to have some common structural features thought to be important in driving the formation of the phase. The most critical molecular parameter appears to be a large dipole along the major axis of the molecule, and it has been suggested that this must be greater than 9 D. 24 A second structural prerequisite is some degree of lateral steric bulk such that the molecule has, what may be described as, a wedge shape.…”

Implementation of a cylindrical distribution function for the analysis of anisotropic molecular dynamics simulations.

“…27 Polar nematic order gives rise to extremely large ferroelectric polarisations, 25 which are of interest to both fundamental and applied science. [28][29][30][31] We simulated a polar nematic configuration of the NF material RM554 (Figure 3a) 32 by taking an isotropic configuration of 680 molecules with liquid-like density of 1.1 g cm 3 and applying a static electric field (0.1 V nm -1 ) along the y-axis; this gives a large polar order parameter (<P1>) of ~ 0.9 and an orientational order parameter (<P2>) of ~ 0.65. Following this, a production MD simulation (without biasing field) of 250 ns was performed from this polar configuration at a temperature of 375 K with anisotropic pressure coupling; note that, as with prior simulations, the polar order is essentially constant over the entire production run.…”

A new order of liquids: polar order in nematic liquid crystals

“…In 2017 two materials were reported – RM734 5 and DIO 6 – that are now understood to have polar nematic order and are ferroelectric, over a century after Born's conjecture. 7–9 This so-called ferroelectric nematic (N F ) phase displays a slew of unique properties: ferroelectric properties with huge spontaneous polarisation, 8,10 polar domains, 10 strong non-linear optical response, 11 unique electrooptic responses, 12 and thermal gradient-induced circular motion of particles, 13 to name a few. The remarkable properties of the N F phase, coupled with fluidity and relative ease of alignment, 14 will ensure this field flourishes in the decades to come.…”