Related papers: Ferroelectric ordering and electroclinic effect in…
The proton ordering model for the KH$_{2}$PO$_{4}$ type ferroelectrics is modified by taking into account the dependence of the effective dipole moments on the proton ordering parameter. Within the four-particle cluster approximation we…
Interfacial ferroelectricity, prevalent in various parallel-stacked layered materials, allows switching of out-of-plane ferroelectric order by in-plane sliding of adjacent layers. Its resilience against doping potentially enables…
Using the previously developed model we study the electrocaloric effect (ECE) in antiferroelectric crystals of squaric acid. At low temperatures, the polarization reorientation by the electric field applied along the crystallographic $a$…
We investigated the electrical properties of the liquid crystal compound, known as an RM734, exhibiting a ferroelectric nematic phase. The influence of alternating (AC) and direct (DC) current electric fields on the switching process of the…
Understanding nanoscale mechanisms responsible for the recently discovered ferroelectric nematics can be helped by direct visualization of self-assembly of strongly polar molecules. Here we report on scanning tunneling microscopy (STM)…
We show that development of polar order may spontaneously destroy the lamellar structure of a liquid crystal. This results in an unusual sequence of phases with the ferroelectric nematic phase appearing below a non-polar smectic phase. The…
We are concerned with the modification of liquid crystalline and polar order in SmC* liquids by illumination. In particular we show that non-uniformity due to absorption and also dynamics, can be complex. The variation of polarization with…
We report the smectic $A_F$, a new liquid crystal phase of the ferroelectric nematic realm. The smectic $A_F$ is a phase of small polar, rod-shaped molecules which form two-dimensional fluid layers spaced by approximately the mean molecular…
We present and analyze a model for the combination of bulk and surface electroclinic effects in the smectic-A* (Sm-A) phase near a Sm-A*--Sm-C* transition. As part of our analysis we calculate the dependence of the surface tilt on external…
The polarization and density modulation associated with antiferroelectric ordering is studied experimentally as a function of temperature in two ferroelectric nematic liquid crystals, the prototypical single compound (DIO) and a commercial…
Using a generalized Landau theory involving orientational, layering, tilt, and biaxial order parameters we analyze the smectic-A* and smectic-C* (Sm-A* -- Sm-C*) transition, showing that a combination of small orientational order and large…
The recent discovery of the ferroelectric splay nematic phase has opened the door to experimental investigation of one of the most searched liquid crystal phases in decades, with high expectations for future applications. However, at this…
The recently discovered ferroelectric nematic liquid crystals have been reported to exhibit very large dielectric permittivity values. Here, we report a systematic investigation of the dielectric behavior of a prototypical ferroelectric…
The proton ordering model for the KH$_{2}$PO$_{4}$ type ferroelectrics is modified by taking into account non-linear effects, namely, the dependence of the effective dipole moments on the proton ordering parameter. Within the four-particle…
Ferroelectric nematic fluids are promising materials for tunable nonlinear photonics, with applications ranging from second harmonic generation to sources of entangled photons. However, the few reported values of second-order…
The ferroelectric nematic phase (N$_{\text{F}}$) has quickly become the most studied system in liquid crystal research. In this work, we investigate the origin of such polar structure by studying a compound for which the N$_{\text{F}}$…
The temperature-dependent polarization of SrTiO_3 thin films is investigated using confocal scanning optical microscopy. A homogeneous out-of-plane and inhomogeneous in-plane ferroelectric phase are identified from images of the linear…
The flexoelectric (FE) effect provides a linear coupling between electric polarization and orientational deformation in liquid crystals. It influences many electrooptical phenomena and it is used in some bistable nematic devices. A…
The coupling between magnetic order and ferroelectricity has been under intense investigation in a wide range of transition-metal oxides. The strongest coupling is obtained in so-called magnetically-induced multiferroics where…
By means of first-principles simulations, we unambiguously show that improper ferroelectricity in magnetite in the low-temperature insulating phase is driven by charge-ordering. An accurate comparison between monoclinic ferroelectric Cc and…