INTRODUCTION The currently known ferroelectric liquid crystals have relatively complex tilted smectic phases constituted by chiral [1] or by banana-shaped molecules [2]. Although numerous novel materials of this type continue to appear [3], the development of ferroelectric nematic phases, i.e. of truly fluid phases with an overall polar order, would be a goal of considerable importance [4, 5]. ...

Ferroelectric materials, which exhibit switchable polarization and are piezoelectric, have been extensively studied because of their applications in nonvolatile memory and energy harvesting devices.[1,2] Recently, ferroelectric nanostructures have attracted great interest as they provide a platform to investigate the size effect of ferroelectricity and enable integration with prevailing miniatu...

Although the magnetoelectric effects - the mutual control of electric polarization by magnetic fields and magnetism by electric fields, have been intensively studied in a large number of inorganic compounds and heterostructures, they have been rarely observed in organic materials. Here we demonstrate magnetoelectric coupling in a metal-organic framework [(CH3)2NH2]Mn(HCOO)3 which exhibits an or...

The polarization of the ferroelectric polymer P(VDF-TrFE) decreases upon prolonged cycling. Understanding of this fatigue behavior is of great technological importance for the implementation of P(VDF-TrFE) in random-access memories. However, the origin of fatigue is still ambiguous. Here we investigate fatigue in thin-film capacitors by systematically varying the frequency and amplitude of the ...

In ferroelectric materials, hysteresis behavior is very difficult to model due to its nonlinear and history-dependent characteristics. Among approaches that are able to describe unsaturated loops, many of them are either very complicated numerical procedures must be employed or the resulting loops contain some undesirable or defective features. In this work, a simple hysteresis model based on a...

The temperature of the transition to the polar state in ferroelectric composites, representing spherical ferroelectric inclusions embedded in a dielectric matrix, under a depolarizing field effect is investigated. This temperature is determined both in the absence and presence of screening effects of the depolarizing field of the bound charges of spontaneous polarization at the inclusions surfa...

Electric dipole engineering is now an emerging technology for high electron-mobility transistors, ferroelectric random access memory and multiferroic devices etc. Although various studies to provide insight into dipole moment behaviour, such as phase transition, order and disorder states, have been reported, macroscopic spontaneous polarization has been mainly discussed so far. Here, visualizat...

The effect of electron irradiation on the ferroelectric properties ofLangmuir-Blodgett films of the copolymer poly(vinylidene fluoride-trifluoroethylene) isinvestigated using 1.26 MeV electrons with dosages from 16 to 110 Mrad. Films wereirradiated in the ferroelectric state to investigate the effect of defect introduction inultrathin films. Electron irradiation is known to ...

We review the role that first-principles calculations have played in understanding the effects of substrate-imposed misfit strain on epitaxially grown perovskite ferroelectric films. We do so by analyzing the case of BaTiO3, complementing our previous publications on this subject with unpublished data to help explain in detail how these calculations are done. We also review similar studies in t...

Ferroelectric relaxors belong to a subgroup of ferroelectric materials. Relaxors are characterised by unique dielectric, polarization, electromechanical and electro-optical properties. These extraordinary properties make them suitable for high technological electronic devices such as sensors, actuators, electro or elasto-optic and photorefractive elements. Understanding the origin of these prop...