Interfacial strain gradients in oxide epitaxial thin films provide an interesting opportunity to study flexoelectric effects and their potential applications. Oxide epitaxial thin films can exhibit giant and tunable flexoelectric effects, which are six or seven orders of magnitude larger than those in conventional bulk solids. The strain gradient in an oxide epitaxial thin film can generate an ...

The direct measurement of flexoelectric coefficients in epitaxial thin films is an unresolved problem, due to the clamping effect substrates which induces a net strain (and hence parasitic piezoelectricity) addition gradients and flexoelectricity. Herein, we propose demonstrate use van der Waals epitaxy as successful strategy for measuring intrinsic (clamping-free = films. We have made, measure...

We show that patterned surfaces can promote bistable configurations of nematics for reasons other than the symmetry of the surface. Numerical and analytical calculations reveal that a nematic liquid crystal in contact with a striped surface is subject to the competing aligning influences of elastic anisotropy, differing energy cost of various types of deformation, and flexoelectricity, curvatur...

This article investigates the size dependent on piezoelectrically layered perforated nanobeams embedded in an elastic foundation considering material Poisson’s ratio and flexoelectricity effects. The composite beam is composed of a regularly squared cut-out core with two piezoelectric face sheet layers. An analytical geometrical model adopted to obtain equivalent variables core. To capture effe...

2014 Using the direct flexoelectric effect in an hybrid (homeotropic-planar) nematic cell, we have measured the bulk flexoelectric coefficient e* for two cyanobiphenyl compounds, 8CB and 8OCB. For 8CB, the flexo coefficient is comparable in sign and magnitude with that of MBBA, i.e. e* ~ + 10-4 cgs. 8OCB presents an anomalously large and negative e* ~ 5 x 10-4 cgs. The small influence of the cy...