相关论文: Dielectric Response in Microscopically Heterogeneo…
A flexoelectric peridynamic (PD) theory is proposed. Using the PD framework, the formulation introduces, perhaps for the first time, a nanoscale flexoelectric coupling that entails non-uniform strain in centrosymmetric dielectrics. This…
"Hidden phases" are metastable collective states of matter that are typically not accessible on equilibrium phase diagrams. These phases can host exotic properties in otherwise conventional materials and hence may enable novel functionality…
The investigation of the structural phase transition in the vicinity of the Curie temperature $T_c$ of LiNb$_{1-x}$Ta$_x$O$_3$ crystals is motivated by the expected combination of advantageous high-temperature properties of LiNbO$_3$ and…
It has been known for a long time that the low temperature behavior shown by the dielectric constant of quantum paraelectric $SrTiO_{3}$ can not be fitted properly by Barrett's formula using a single zero point energy or saturation…
The current controversies about the existence of an intermediate 'beta' phase of BiFeO_3 and the high temperature paraelectric 'gamma' phase are resolved by studying the sequence of ferroic transitions in 0.8BiFeO_3-0.2Pb(Fe_1/2Nb_1/2)O_3…
Dabconium hybrid perovskites include a number of recently-discovered ferroelectric phases with large spontaneous polarisations. The origin of ferroelectric response has been rationalised in general terms in the context of hydrogen bonding,…
The rotational instability of the electric polarization P during phase transformations between ferroelectric phases is of great practical interest, since it may be accompanied by extremely large values of the piezoelectric coefficient, and…
We apply ab-initio quantum chemical methods to calculate correlation effects on cohesive properties of NiO, thereby extending a recently proposed scheme to transition metal oxides with partially filled $d$-bands. We obtain good agreement…
A detailed investigation using variable temperature powder neutron diffraction demonstrates that BiFeO3 undergoes a phase transition from the ferroelectric alpha phase (rhombohedral, R3c) to a paraelectric beta phase (orthorhombic, Pbnm)…
We have used a first-principles-based scheme to compute the temperature-versus-misfit strain ``Pertsev'' phase diagram of ultrathin films of {\sl incipient} ferroelectric KTaO$_3$. Our results suggest that, at variance with the bulk…
The consideration of size-induced ferroelectric-paraelectric phase transition for conventional and incipient ferroelectrics thin films with perovskite structure was carried out in phenomenological theory framework of…
For the first time, the dielectric response of a BaTiO3 thin film under an AC electric field is investigated using time-resolved X-ray absorption spectroscopy at the Ti K-edge to clarify correlated contributions of each constituent atom on…
Nominally pure nanocrystalline KTaO3 was thoroughly investigated by micro-Raman and magnetic resonance spectroscopic techniques. In all samples the defect driven ferroelectricity and magnetism are registered. Both ordering states are…
Natural interfaces in ferroic oxides have developed into versatile playgrounds for studying electronic correlation effects in 2D systems. The microscopic origin of the emergent local electronic properties is often debated, however, as…
We develop a first-principles scheme to study ferroelectric phase transitions for perovskite compounds. We obtain an effective Hamiltonian which is fully specified by first-principles ultra-soft pseudopotential calculations. This approach…
The existence of weak solutions to the obstacle problem for a nonlocal semilinear fourth-order parabolic equation is shown, using its underlying gradient flow structure. The model governs the dynamics of a microelectromechanical system with…
Dielectric response as a function of frequency for high-permittivity dielectric and ferroelectric materials is discussed emphasizing the dynamic behaviour in the microwave and infrared range. After introducing the usual modelling of the…
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 demonstrate an approach for calculating temperature-dependent quantum and anharmonic effects with beyond density-functional theory accuracy. By combining machine-learned potentials and the stochastic self-consistent harmonic…
We describe the static dielectric response of ferroelastic-dielectric microcomposites. Its dependence on temperature, pressure and concentration is considered for smaller concentrations and for temperatures above the critical temperature.…