相关论文: Dielectric Response in Microscopically Heterogeneo…
Polycrystalline sample of (Ba_{0.90}Pb_{0.10})(Ti_{0.90}Sn_{0.10})O_3 was obtained by means of a conventional ceramic technology. The dielectric measurements were performed depending on temperature and frequency of electric measuring field.…
A dielectric nonlinear response in model two-phase composites, prepared from a displacive ferroelectric material with a dominant dielectric response due to a single oscillator ferroelectric mode and a dielectric material, is characterized…
Recent experiments have demonstrated that light can induce a transition from the quantum paraelectric to the ferroelectric phase of SrTiO$_3$. Here, we investigate this terahertz field-induced ferroelectric phase transition by solving the…
The advent in this century of nano and microelectronics requires, by part of physicists and engineers, the need of an explanation of electrical phenomena such as the interaction of a body with external electric fields at its atomic…
Low temperature properties of BaZrO3 are revealed by combining experimental techniques (X-ray diffraction, neutron scattering and dielectric measurements) with theoretical first-principles-based methods (total energy and linear response…
Quantitative description of finite-temperature properties of displacive ferroelectrics, and in particular the critical behavior, is of fundamental importance to both theory and device design, going beyond the Landau-Ginzburg approach, which…
We present the results of the high-temperature neutron and x-ray diffraction experiments on the Ca3-xSrxTi2O7 (x = 0.5, 0.8, 0.85, 0.9) compounds. The ferro- to paraelectric transition in these hybrid improper ferroelectric materials arises…
Whereas low-temperature ferroelectrics have a well understood ordered spatial dipole arrangement, the fate of these dipoles in paraelectric phases remains poorly understood. Using density functional theory (DFT), we find that unlike the…
An effective Hamiltonian for the ferroelectric transition in $PbTiO_3$ is constructed from first-principles density-functional-theory total-energy and linear-response calculations through the use of a localized, symmetrized basis set of…
The structural phase transition in hexagonal BaMnO$_3$ occurring at $T_c$=130 K was studied in ceramic samples using electron and X-ray diffraction, second harmonic generation as well as by dielectric and lattice dynamic spectroscopies. The…
We have begun a study of quantum ferroelectrics and paraelectrics. Simple 2D short-range lattice model hamiltonians are constructed, keeping in mind the phenomenology of real perovskite systems, like $SrTiO_{3}$ and $KTaO_{3}$. Pertinent…
The ferroelectric to paraelectric phase transition in LiTaO$_3$ and in pure as well as Mg doped LiNbO$_3$ is investigated theoretically by atomistic calculations in the framework of the density functional theory, as well as experimentally…
A complete mapping in the Brillouin zone of the structural instability associated with the ferroelectric phase transitions of KNbO$_3$ has been obtained by first-principles calculations using an LAPW linear response approach. The wavevector…
Physical effects caused by the presence of interfaces between the domains of coexisting ferroelectric and antiferroelectric phases in solid solutions with small difference in free energies of the ferroelectric and antiferroelectric states…
We analyze a system of polar molecules in a one-dimensional optical lattice. By controlling the internal structure of the polar molecules with static electric and microwave fields, we demonstrate the appearance of a quantum phase transition…
The electronic and structural properties of Li$B$O$_3$ ($B$=V, Nb, Ta, Os) are investigated via first-principles methods. We show that Li$B$O$_3$ belong to the recently proposed hyperferroelectrics, i.e., they all have unstable longitudinal…
The question on the dominant driving mechanism (displacive or order-disorder) at each structural phase transition of KNbO3 is investigated by means of molecular dynamics simulations. To this purpose, we first develop a shell model by…
For the first time we predict the conditions of superparaelectric phase appearance in the ensemble of non-interacting spherical ferroelectric nanoparticles. The superparaelectricity in nanoparticle was defined by analogy with…
Light-induced ferroelectricity in quantum paraelectrics is a new avenue of achieving dynamic stabilization of hidden orders in quantum materials. In this work, we explore the possibility of driving transient ferroelectric phase in the…
We explain the phenomena of ferroelectric phase transition temperature $T_c$ enhancement beyond the end members in perovskite solid solutions like BiMeO$_3$-PbTiO$_3$ (Me=Sc, In, etc.) is related to nonlinear and spatial correlation…