Related papers: Conservation of dielectric constant upon amorphiza…
High-kappa dielectrics for insulating layers are a current key ingredient of microelectronics. X2O3 sesquioxide compounds are among the candidates. Here we show for a typical material of this class, ScO3, that the relatively modest…
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$_3$…
The complex impedance of a Pr0.67Ca0.33MnO3 crystal has been measured. The frequency dependence is studied for a wide range of temperatures (50K-403K) and is found to be characteristic of relaxation process with a single Debye time…
Realistic models of amorphous ZrO2 are generated in a ``melt-and-quench'' fashion using ab-initio molecular dynamics in a plane-wave pseudopotential formulation of density-functional theory. The structural properties of the resulting…
Ferroelectricity in perovskites is known to be suppressed by a moderate hydrostatic pressure. The notion that a polar instability should reappear in a higher pressure regime is well accepted theoretically but experiments have failed so far…
Using first-principles calculations, we predict that tunable ferroelectricity can be realized in oxide perovskites with the Grenier structure and ordered oxygen vacancies. Specifically, we show that $R_{1/3}A_{2/3}\mathrm{FeO}_{2.67}$…
The octahedron tilt transitions of ABX_3 perovskite-structure materials lead to an anti-polar (or antiferroelectric) arrangement of dipoles, with the low temperature structure having six sublattices polarized along various crystallographic…
Frequency dependence of the dielectric constant of complex perovskite oxide Ba(1-x)La(x)Ti(1-x)Cr(x)O3 (BLTC) ceramics with the composition ratio 0.4<= x <= 0.7 is precisely measured in the temperature range from 20 K to 300 K, and the…
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…
Using finite-temperature phonon calculations and the Lyddane-Sachs-Teller relations, we calculate ab initio the static dielectric constants of 78 semiconducting oxides and fluorides with cubic perovskite structures at 1000 K. We first…
We describe the static dielectric response of ferroelastic-dielectric microcomposites. Dependence on temperature, pressure and concentration is considered for temperatures in the paraelastic transition. In recent years there has been…
The recent observation of a ferroelectric-like structural transition in metallic LiOsO$_3$ has generated a flurry of interest in the properties of polar metals. Such materials are thought to be rare because free electrons screen out the…
The ferroelectric polarization of perovskite oxides is much larger than implied by displacement of static ionic charges. We use an explicitly correlated scheme to investigate the phenomenon; charge transport is evaluated as a geometric…
We use first-principles density functional theory calculations to investigate the dielectric response of BaZrO$_3$ perovskite. A previous study [Arkbarzadeh {\em et al.} Phys. Rev. B {\bf 72}, 205104 (2005)] reported a disagreement between…
High-temperature electronic materials are in constant demand as the required operational range for various industries increases. Here we design $(A,A^\prime)B_2$O$_6$ perovskite oxides with [111] ``rock salt" $A$-site cation order and…
We derive an expression for the static dielectric constant of the colloidal susp ensions based on the electrokinetic equations. The analysis assumes that the ions have the same diffusivity, and that the double layer is much thinner than the…
Oxygen vacancy ordering in perovskite-type transition-metal oxides plays an important role in the emergence of exotic electronic properties, as typified by superconducting cuprates. In this study, we predict the stability of…
Hyperferroelectrics are receiving a growing interest thanks to their unique property to retain a spontaneous polarization even in presence of a depolarizing field. Nevertheless, general microscopic mechanisms driving hyperferroelectricity,…
While nature provides a plethora of perovskite materials, only a few exhibits large ferroelectricity and possibly multiferroicity. The majority of perovskite materials have the non-polar CaTiO$_3$(CTO)structure, limiting the scope of their…
We present a thorough dielectric investigation of the hexagonal perovskites La1.2Sr2.7IrO7.33 and La1.2Sr2.7RuO7.33 in a broad frequency and temperature range, supplemented by additional infrared measurements. The occurrence of giant…