Harvesting Single Ferroelectric Domain Stressed Nanoparticles for Optical and Ferroic Applications

We describe techniques to selectively harvest single ferroelectric domain nanoparticles of BaTiO3 as small as 9 nm from a plethora of nanoparticles produced by mechanical grinding. High resolution transmission electron microscopy imaging shows the unidomain atomic structure of the nanoparticles and reveals compressive and tensile surface strains which are attributed to the preservation of ferroelectric behavior in these particles. We demonstrate the positive benefits of using harvested nanoparticles in disparate liquid crystal systems

Asymmetric Freedericksz Transitions from Symmetric Liquid Crystal Cells Doped with Harvested Ferroelectric Nanoparticles

The electrical Freedericksz transition characteristics of planar aligned liquid crystal cells doped with harvested single ferroelectric domain 9 nm nanoparticles of BaTiO3 have been measured. We demonstrate for the first time that the electrical pre-history of the cells imparts significant polarity sensitivity to the Freedericksz characteristics. The presence of harvested single domain ferroelectric nanoparticles enables cells to be programmably semi-permanently polarized. This reduces or increases the Freedericksz transition threshold by 0.8 V, depending on the polarity of the applied voltage, giving a net 1.6 V Freedericksz threshold asymmetry for 8 μm thick cells filled with TL205 liquid crystal