Role of Defects in the Ferroelectric Relaxer Lead Scandium Tantalate

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Poor electrical strength of the ceramic–vacuum interface restricts the development of various electrical/electronic devices. Limitations of solutions based on conventional ceramics fabrication procedures are becoming prominent with the further demand for compactness and performance improvement. In this study, a fabrication method utilising 3D printing technology is proposed to construct ceramic insulation with designed structures. The processing characteristics, dielectric properties and morphologies of 3D‐

Properties in crystalline and ordered materials tend to be anisotropic, with their orientation affecting the macroscopic behavior and functionality of materials. The ability to image the orientation of anisotropic material properties in three dimensions (3D) is fundamental for the understanding and functionality-driven development of novel materials. With the development of x-ray linear dichroic orientation tomography (XL-DOT), it is now possible to non-destructively map 3D orientation fields in micrometer-

Multiferroic materials show, in a single phase, at least two ferroic properties. The latter are are (anti-)ferroelectricity, (anti-)ferromagnetism or (anti-)ferroelasticity. Interesting applications can use the properties of multiferroics, especially with those presenting magnetic and electric coupling. The ability of controlling a magnetic field with an electric field, using the magnetoelectric coupling, could have interesting applications in spintronics (spin transport electronics), electronic memory devi

The transverse piezoelectric coefficient e31,f of Al1-xScxN thin films was investigated as a function of composition. It increased nearly 50% from x = 0 to x = 0.17. As the increase of the dielectric constant was only moderate, these films are very suitable for energy harvesting, giving a 60% higher transformation yield (x = 0.17) as compared to pure AlN. A higher doping might even lead to a 100% augmentation. The thickness strain response (d33,f) was found to increase proportionally to the ionic part of th

A uniaxial compressive stress significantly modifies the dielectric and piezoelectric response of Pb(Zr,Ti)O3 (PZT)-based piezoceramics. In soft PZT, the pre-stress decreases both the piezoelectric coefficient and its increment with increasing dynamical stress amplitude. However, an increase of both quantities is shown in hard PZT. Similar effects are observed in the dielectric response. It is proposed that the differences between such behaviors are due to the possibility of domain coalescence in the materi

We discuss various decomposition schemes for analysing the dielectric constants of Zr silicates in terms of local properties. Such schemes serve the purpose of predicting the dielectric constants of amorphous alloys, when their system size precludes the possibility of performing accurate first-principles calculations. In particular, we compare two decomposition schemes which have found application in the recent literature. The first scheme is based on a decomposition into basic structural units characterize

Systems with a ferroelectric to paraelectric transition in the vicinity of room temperature are useful for devices. Adjusting the ferroelectric transition temperature (T-c) is traditionally accomplished by chemical substitution - as in BaxSr1-xTiO3, the material widely investigated for microwave devices in which the dielectric constant (epsilon(r)) at GHz frequencies is tuned by applying a quasi-static electric field(1,2). Heterogeneity associated with chemical substitution in such films, however, can broad

Strontium barium niobate thin films have been deposited by pulsed laser deposition on (111)-textured Pt films, p-doped Si(I 00) and Nb doped STO (SrTiO3) single crystals. The deposition parameters were optimized for obtaining phase pure (001)-oriented films from stochiometric targets. The samples were annealed in oxygen to improve top electrode adhesion and reduce oxygen vacancies. The SBN/substrate interfaces were investigated by means of TEM combined with EDAX chemical analysis. Growth on silicon resulted

Lead oxide based ferroelectrics, represented by lead zirconate titanate (Pb(Zr,Ti)O-3) or PZT) are the most widely used materials for piezoelectric actuators, sensors and transducers due to their excellent piezoelectric properties. Considering lead toxicity, there is interest in developing piezoelectric materials that are biocompatible and environmentally friendlier. The low density of non-lead based materials can also be an advantage in transducers for underwater and medical imaging due to expected lower a

We study the dielectric susceptibility of liquid hydrogen chloride at a temperature of 313 K using ab initio molecular dynamics evolving, in a homogeneous electric field. For an evolution in absence of electric field, the calculated neutron structure factor shows good agreement with the experimental one, supporting the structural properties of our model. We obtain the real and imaginary parts of the dielectric susceptibility as a function of frequency from the evolution of the polarization upon the onset of

The motivation of this work derives from the need of the cutting tool industry to improve its products in order to support harder and harder working conditions, namely increasing cutting speeds and working on stronger modern materials. The lifetime of the tools is limited by plastic deformation that occurs at the cutting edge under working conditions, which involve high temperatures and stresses. The high temperature deformation of the materials that are used for the production of cutting tools is studied.

Homogeneous electric fields are treated within density functional calculations with periodic boundary conditions. A nonlocal energy functional depending on the applied field is used within an ab initio molecular dynamics scheme. The reliability of the method is demonstrated in the case of bulk MgO for the Born effective charges, and the high- and low-frequency dielectric constants.

Deposition of a hydrothermal method has a number of advantages; low deposition temperature, high-purity, deposition on a three-dimensional structure, and a large thickness. The present paper investigates the improvement of an epitaxial lead zirconate titanate (PZT) thin film deposited via hydrothermal synthesis. The critical parameter contributing to the film morphology was revealed to be the holding position of the reaction solution during deposition. In addition to this improvement, the SrRuO3 bottom elec

The influence of addition of a low-loss linear dielectric material to a tunable ferroelectric material has been investigated in terms of the electrostatic consideration. The calculations of the dielectric loss and dielectric non-linearity of ferroelectric-dielectric composites have been performed by using three different models. On the basis of results obtained, the figure of merit of the composite material has been evaluated. No improvement of the figure of merit of composite material compared to the pure

Urotropin (U) and azelaic acid (AA) form 1:1 co-crystals (UA) that give rise to a rather complex diffraction pattern, the main features of which are diffuse rods and bands in addition to the Bragg reflections. UA is characterized by solvent inclusions, parasite phases, and high vacancy and dislocation densities. These defects compounded with the pronounced tendency of U to escape from the crystal edifice lead to at least seven exotic phase transitions (many of which barely manifest themselves in a different

Relaxor Pb(Sc1/2Nb1/2)O-3 (PSN) thin films without pyrochlore phase were processed from the modified alkoxide solution precursors. The preparation of single phase PSN thin films has a narrow processing window due to the appearance of an undesirable pyrochlore phase and volatility of PbO. Thin film processing has been improved through selection of precursor solutions, heat treatment and optimized deposition-condition are optimized. Especially, the effects of Pt substrates seeded with additional layers upper

It is shown that a strong but diffuse dielectric anomaly, commonly expected only in disordered ferroelectrics, may be inherent in strained and defect-free perovskite ferroelectric thin films. The origin of this unusual anomaly, which was never predicted for a defect-free system, is the overcritical trace of a critical point in the film phase diagram, This possibility is illustrated by the mean-field thermodynamic calculations performed for (111)-oriented PbTiO3 films epitaxially grown on dissimilar cubic su

Pb(Zr,Ti)O-3 (PZT) and Pb(Zr,Ti,Nb)O-3 (PNZT) thin films were grown on platinized silicon substrates by r.f. magnetron sputtering followed by a post-annealing treatment. The Niobium, Nb, concentration varied from 1 to 7 at.% by increment of 1 at.%. The effects of the Nb introduction on the PZT electrical properties, i.e, dielectric, ferroelectric and piezoelectric ones were investigated. The relative dielectric constant (epsilon (T)) was very sensitive to the Nb introduction; epsilon (T) reaches 1100 for a

Electromechanical properties of a number of ferroelectric films including PbZrxTi1-xO3(PZT), 0.9PbMg(1/3)Nb(2/3)O(3)-0.1PbTiO(3)(PMN-PT), and SrBi2Ta2O9(SBT) are investigated using laser interferometry combined with conventional dielectric measurements. Effective electrostriction coefficients of the films, Q(eff), are determined using a linearized electrostriction equation that couples longitudinal piezoelectric coefficient, d(33), with the polarization and dielectric constant. It is shown that, in PZT film

Transparent single crystals of the perovskite Pb(Zn-1/3,Nb-2/3)O-3-PbTiO3 (PZN-PT) were grown from different lead fluxes in sealed platinum crucibles. A temperature gradient furnace was used (temperature gradient on crucible: 30-50 degreesC). Optimization of growth temperature range and cooling rates was carried out in fluxes of PbO, Pb3O4 with and without an addition of B2O3. The growth nature range was typically 1150 degreesC --> 930 degreesC (on crucible top) with cooling rates of 0.8 - 1 degreesC/h for

Role of Defects in the Ferroelectric Relaxer Lead Scandium Tantalate

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