Lateral Electric Field Switching in Thin Ferroelectric Nematic Liquid Crystal Cells

This study shows that in cells with a small thicknesses, the permanent polarization in the ferroelectric nematic phase of RM734 is aligned in the opposite direction as the rubbing. The electrode configuration induces an in-plane field near one substrate and a normal field near the other substrate. At low voltages, the permanent polarization rotates parallel to the substrate plane when its original orientation is at an angle with the electric field. The rotation occurs over a distance of more than 100 μm, where the applied electric field is very small. At higher voltages, the polarization aligns perpendicularly to the substrates under influence of the transverse electric field. After removing the voltage, sometimes a slow reorientation of the polarization can be observed, which is ascribed to the slow release of ionic species. The results provide insight in the complex mechanisms that are involved in the switching of ferroelectric nematic liquid crystals.This study shows that in cells with a small thicknesses, the permanent polarization in the ferroelectric nematic phase of RM734 is aligned in the opposite direction as the rubbing. The electrode configuration induces an in-plane field near one substrate and a normal field near the other substrate. At low voltages, the permanent polarization rotates parallel to the substrate plane when its original orientation is at an angle with the electric field. The rotation occurs over a distance of more than 100 μm, where the applied electric field is very small. At higher voltages, the polarization aligns perpendicularly to the substrates under influence of the transverse electric field. After removing the voltage, sometimes a slow reorientation of the polarization can be observed, which is ascribed to the slow release of ionic species. The results provide insight in the complex mechanisms that are involved in the switching of ferroelectric nematic liquid crystals.