相关论文: Concentration phase diagram of Ba(x)Sr(1-x)TiO3 so…
The evolution of topology of the B-B2O3 phase diagram has been studied at pressures up to 24 GPa using models of phenomenological thermodynamics with interaction parameters derived from experimental data on phase equilibria at high…
Ferroelectric and dielectric properties of polydomain (twinned) single-crystal Pb(Zr1-xTix)O3 thin films are described with the aid of a nonlinear thermodynamic theory, which has been developed recently for epitaxial ferroelectric films…
The phase diagram of Sr_1-xEu_xTiO_3 is determined experimentally by electron paramagnetic resonance and resistivity measurements and analyzed theoretically within the self-consistent phonon approximation as a function of x ([0.03-1.0]).…
The ferroelectric phase transition in barium titanate under pressure was studied within the framework of Landau-Ginzburg theory using differential scanning calorimetry. An innovative method for high-sensitive thermal measurements under…
SrTiO$_{3}$, a quantum paraelectric, becomes a metal with a superconducting instability after removal of an extremely small number of oxygen atoms. It turns into a ferroelectric upon substitution of a tiny fraction of strontium atoms with…
Currently used methods for the description of thermodynamics of ferroelectric thin films (Landau theory or ab initio based Monte-Carlo simulations) are based on an energy expansion in terms of internal degrees of freedom. It was shown that…
By using a symmetry motivated basis to evaluate local distortions against pair distribution function data (PDF), we show without prior bias, that the off-centre Ti displacements in the archetypal ferroelectric BaTiO3 are zone centred and…
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…
Systematic measurements of the resistivity, heat capacity, susceptibility and Hall coefficient are presented for single crystal samples of the electron-doped superconductor Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$. These data delineate an $x-T$ phase…
We study the phase diagram of calcium fluoride (CaF2) under pressure using classical molecular dynamic simulations performed with a simple pairwise interatomic potential of the Born-Mayer-Huggings form. Our results obtained under conditions…
Machine learning has been establishing its potential in multiple areas of condensed matter physics and materials science. Here we develop and use an unsupervised machine learning workflow within a framework of first-principles-based…
Ceramic solid solutions of PbZr(1-x)TixO3 (PZT) with compositions of about x= 0.50 are well-known for their extraordinarily large piezoelectric responses. The latter are highly anisotropic, and it was recently shown that, for the…
A detailed defect energy level map was investigated for heterostructures of 26 unit cells of LaAlO3 on SrTiO3 prepared at a low oxygen partial pressure of 10-6 mbar. The origin is attributed to the presence of dominating oxygen defects in…
SrTiO$_{3}$ undergoes a cubic-to-tetragonal phase transition at 105K. This antiferrodistortive transition is believed to be in competition with incipient ferroelectricity. Substituting strontium by isovalent calcium induces a ferroelectric…
The phase-field-crystal model for liquid crystals is solved numerically in two spatial dimensions. This model is formulated with three position-dependent order parameters, namely the reduced translational density, the local nematic order…
Combining effective Hamiltonian and direct $ab$ $initio$ computation, we obtain the phase diagram of SnTiO$_{3}$ with respect to epitaxial strain and temperature, demonstrating the complex features of the phase diagram and providing insight…
High-resolution thermal-expansion and specific-heat measurements were performed on single crystalline BaFe2(As1-xPx)2 (0 < x < 0.33, x = 1). The observation of clear anomalies allows to establish the thermodynamic phase diagram which…
Proximity to phase transitions (PTs) is frequently responsible for the largest dielectric susceptibilities in ferroelectrics. The impracticality of using temperature as a control parameter to reach those large responses has motivated the…
Modeling ferroelectric materials from first principles is one of the successes of density-functional theory, and the driver of much development effort, requiring an accurate description of the electronic processes and the thermodynamic…
The structural phase diagram of the Pb-free ferroelectric (Na1/2Bi1/2)1-xBaxTiO3 (NBT-BT), x<0.1, has been explored by Raman spectroscopy at temperatures from 10 to 470 K. The data provide clear evidence for a proposed…