相关论文: Higher-order Landau-Devonshire theory for BaTiO3
The crystal and magnetic structure of LaTiO3 ~ has been studied by x-ray and neutron diffraction techniques using nearly stoichiometric samples. We find a strong structural anomaly near the antiferromagnetic ordering, T$_N$=146 K. In…
The spontaneous polarization of epitaxial BaTiO$_3$/SrTiO$_3$ superlattices is studied as a function of composition using first-principles density functional theory within the local density approximation. With the in-plane lattice parameter…
Method of derivation of phenomenological thermodynamic potential of solid solutions is proposed in which the interaction of the order parameters of constituents is introduced through the account of elastic strain due to misfit of the…
I discuss the analytic structure of thermodynamic quantities for complex values of thermodynamic variables within Landau theory. In particular, the singularities connected with phase transitions of second order, first order and cross over…
Phase structure is studied for a system which has symmetry group SU(3) and is described by SU(3)-${\bf 3 \times 3}$ order parameter. The study is rested on SU(3)-Ginzburg-Landau effective potential constructed as a preliminary.
We show that nonlinear continuum elasticity can be effective in modeling plastic flows in crystals if it is viewed as Landau theory with an infinite number of equivalent energy wells whose configuration is dictated by the symmetry group…
Cylindrical BaTiO3 nanorods embedded in (100)-oriented SrTiO3 epitaxial film in a brush-like configuration are investigated in the framework of the Ginzburg-Landau-Devonshire model. It is shown that strain compatibility at BaTiO3/SrTiO3…
The question of the origin of the piezoelectric properties enhancement in perovskite ferroelectrics is approached by analyzing the Gibbs free energy of tetragonal BaTiO3, PbTiO3 and Pb(Zr,Ti)O3 in the framework of the…
We have proposed the polarization rotation theory to understand the underlying physics of the large piezoelectric effect in ferroelectric crystals by referring to the coherent rotation model in ferromagnetism. When both the electric field…
We discover a rare structural manifestation of the Goldstone paradigm in a hexagonal polytype of the archetypal ferroelectric BaTiO3. First-principles calculations confirm the Goldstone character of the order parameter, and high-resolution…
The crystal structure and local spontaneous polarization of (BaTiO3)m/(SrTiO3)n superlattices is calculated using a first-principles density functional theory method. The in-plane lattice constant is 1% larger than the SrTiO3 substrate to…
We analyze the thermodynamical potential of a lattice gas model with three components and five parameters using the methods of Catastrophe Theory. We find the highest singularity, which has codimension five, and establish its…
A shell model for ferroelectric perovskites fitted to results of first-principles density functional theory (DFT) calculations is strongly affected by approximations made in the exchange-correlation functional within DFT, and in general not…
Landau's phenomenological theory of Fermi liquids is a fundamental paradigm in many-body physics that has been remarkably successful in explaining the properties of a wide range of interacting fermion systems, such as liquid helium-3,…
The effect of epitaxial strain on the phonon spectra, crystal structure, spontaneous polarization, dielectric, piezoelectric, and elastic properties of (001)-oriented ferroelectric (BaTiO$_3$)$_m$/(SrTiO$_3$)$_n$ superlattices ($m = n =…
Composition-dependent structural and polar properties of epitaxial short-period CaTiO_3/SrTiO_3/BaTiO_3 superlattices grown on a SrTiO_3 substrate are investigated with first-principles density-functional theory computational techniques.…
The bandstructure was calculated by the full-potential linearized augmented plane wave method. The result reveals two important insights to the novel second harmonic generation (SHG) of alpha-phase lithium iodate ($\alpha-LiIO_{3}$)…
Properties of (BaTiO$_3$)$_1$/(BaZrO$_3$)$_n$ ferroelectric superlattices (SLs) with $n = {}$1--7 grown in the [001] direction are calculated from first principles within the density functional theory. It is revealed that the…
We study potential and electron density depth profiles in accumulation, inversion and depletion layers in crystals with large and nonlinear dielectric response such as $\mathrm{SrTiO_3}$. We describe the lattice dielectric response using…
The properties of materials near structural phase transitions are often successfully described in the framework of Landau theory. While the focus is usually on phase transitions, which are induced by temperature changes approaching a…