相关论文: Theory of Size-Driven Transitions in Displacive an…

The films of order-disorder type ferroelectrics were considered in the mean field approximation taking into account depolarization field. It was shown that size effects in this system could be described on the base of bulk system equation…

In this work we explore the overall structural behaviour of the [(CH3)2NH2][Mn(HCOO)3] multiferroic compound across the temperature range where its ferroelectric transition takes place by means of calorimetry, thermal expansion measurements…

The cross-unitcell long displacements in some recent emergent ferroelectrics have actually challenged the classical definition of ferroelectricity, while the relative explorations are still in the early stage and even controversial. In this…

This letter addresses basic questions concerning ferroelectric order in positionally disordered dipolar materials. Three models distinguished by dipole vectors which have one, two or three components are studied by computer simulation.…

General approach for consideration of primary ferroic (ferroelectric, ferromagnetic, ferroelastic) nanoparticles phase transitions was proposed in phenomenological theory framework. The surface stress, order parameter gradient, striction as…

This work reports on magnetic, dielectric, thermodynamic and magnetoelectric properties of Gd$_{1-x}$Y$_{x}$MnO$_{3}$, with 0 \leq x \leq 0.4, with emphasis on the (x, T) phase diagram, towards unraveling the role of the driving mechanisms…

We carry out a completely first-principles study of the ferroelectric phase transitions in BaTiO$_3$. Our approach takes advantage of two features of these transitions: the structural changes are small, and only low-energy distortions are…

We investigate the crystal structure in multiferroic tetragonal perovskite Sr$_{1/2}$Ba$_{1/2}$MnO$_3$ with high accuracy of the order of 10$^{-3}$ Angstrom for an atomic displacement. The large atomic displacement for Mn ion from the…

A four-state model is proposed for description of the sequence of phase transitions in ferroelectric crystals of DMAGaS and DMAAlS type. The ordering processes in the subsystems of DMA groups are considered as a main reason of such…

We present a first-principles study of model domain walls (DWs) in prototypic ferroelectric PbTiO3. At high temperature the DW structure is somewhat trivial, with atoms occupying high- symmetry positions. However, upon cooling the DW…

The collective amplitude mode of the order parameter in displacive ferroelectrics, termed the ferron, represents the amplitude fluctuations of long-range ordered polarization. At temperatures well below phase transition temperature $T_c$,…

While defects are unavoidable in crystals and often detrimental to material performance, they can be a key ingredient for inducing functionalities when tailored. Here, we demonstrate that an A-site-deficient perovskite Y$_{1/3}$TaO$_3$…

A theory to describe the dielectric anomalies and the ferroelectric phase transition induced by oxygen isotope replacement in SrTiO$_3$ is developed. The proposed model gives consistent explanation between apparently contradictory…

In a recent letter [Phys. Rev. Lett. {\bf 75}, 2360 (1996)] we briefly discussed the existence and nature of ferroelectric order in positionally disordered dipolar materials. Here we report further results and give a complete description of…

Experimental investigations of the phase transition in GeTe provide contradictory conclusions regarding the nature of the phase transition. Considering growing interest in technological applications of GeTe, settling these disputes is of…

We report a molecular dynamics study of ab initio quality of the ferroelectric phase transition in crystalline PbTiO3. We model anharmonicity accurately in terms of potential energy and polarization surfaces trained on density functional…

We develop a series of approximations to calculate free energy of a polar liquid. We show that long range nature of dipole interactions between the molecules leads to para-electric state instability at low temperatures and to a second-order…

Monte Carlo simulations are used to examine cooperative creation of polar state in fluids of two-state particles with nonzero dipole in the excited state. With lowering temperature such systems undergo a second order transition from…

Strontium titanate is an incipient ferroelectric in which superconductivity emerges at exceptionally low doping levels. Remarkably, stabilizing the polar phase through strain or chemical substitution has been shown to significantly enhance…

The recent discovery of ferroelectric behavior in few-layer materials, accompanied by the observation of antipolar domains in hexagonal boron nitride and transition metal dichalcogenide moir\'e bilayers, is paving the way for revolutionary…