The solutions for the minimizers of the energy density f (q, p) = Aq2 + Bq4 + p2 + gA,B + ( ) β κ − + | | + | | ′ ′ ′ ′ q p p q q p 2 2 describe the flexoelectric effect with a flexoelectric coupling coefficient β. The order parameters q and p can be visualized as strain and polarisation, respectively. The parameter κ denotes the ratio of intrinsic length scales for q and p. We show that the st...

J. Očenášek,1 H. Lu,2 C. W. Bark,3 C. B. Eom,3 J. Alcalá,4 G. Catalan,5,6 and A. Gruverman2 1New Technologies Research Centre, University of West Bohemia in Pilsen, 30614 Plzeň, Czech Republic 2Department of Physics and Astronomy, University of Nebraska-Lincoln, Nebraska 68588, USA 3Department of Materials Science and Engineering, University of Wisconsin-Madison, Wisconsin 53706, USA 4Departmen...

Polar chiral structures have recently attracted much interest within the scientific community, as they pave way towards innovative device concepts similar to developments achieved in nanomagnetism. Despite growing interest, many fundamental questions related mechanisms controlling appearance and stability of ferroelectric topological remain open. In this context, nanoparticles provide a flexibl...

Small angle X-ray diffraction from the uniaxial nematic phase of certain bent-core liquid crystals is shown to be consistent with the presence of molecular clusters possessing short-range tilted smectic (smectic-C) order. Persistence of these clusters throughout the nematic phase, and even into the isotropic state, likely accounts for the unusual macroscopic behavior previously reported in bent...

For many years it has been commonly accepted that electroconvection (EC) as primary instability in nematic liquid crystals for the "classical" planar geometry requires a positive anisotropy of the electric conductivity, sigma(a), and a slightly negative dielectric anisotropy, epsilon(a). This firm belief was supported by many experimental and theoretical studies. Recent experiments, which have ...

2014 We describe a new flexoelectric volume effect in homogeneous electric field, in the nematic phase of MBBA. An initial splay-bend texture is created by strong antagonistic planar and homeotropic anchoring on two glass plates. This results in a volume flexoelectric polarization. A transverse DC electric field creates a twist of the texture, which can be measured by the resulting wave guided ...

2014 Recent reports have claimed that the simple Rapini-Papoular form for the anchoring energy of nematic liquid crystals is not correct for large distortions. We show that, taking into account the dielectric energy associated with the flexoelectric effect, a reanalysis of the data is consistent with the Rapini-Papoular form. The consideration of flexoelectricity is necessary in most practical ...

We argue that the experimental determination of the flexoelectric coefficients and the surface polarization of the p-pentyl-cyanobiphenil liquid crystal, recently reported by Mazzulla et al. [Phys. Rev. E 64, 021708 (2001)] is questionable. This conclusion follows from the hypothesis performed by the authors to extract the flexoelectric coefficients and the surface polarization from the reflect...