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Materials Science â€ș Materials Chemistry

Ferroelectric and Piezoelectric Materials

Works Count: 85783

Description

This cluster of papers focuses on the advancements in lead-free piezoelectric materials, particularly on ferroelectric and relaxor ferroelectric materials with high piezoelectric properties. It covers topics such as perovskite structure, thin film ferroelectrics, electrocaloric effect, domain wall nanoelectronics, and high energy storage materials.

Keywords

Lead-free Piezoceramics; Ferroelectric Materials; Piezoelectric Properties; Perovskite Structure; Relaxor Ferroelectrics; Thin Film Ferroelectrics; Electrocaloric Effect; Domain Wall Nanoelectronics; High Energy Storage Materials; Phase Boundary Piezoelectrics

Origin of the High Piezoelectric Response in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>PbZr</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi mathvariant="italic">x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>Ti</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="italic">x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>O</mml:mi></mml:mrow


2000-06-05
Ruyan Guo , L. E. Cross , S. E. Park +3 more
High resolution x-ray powder diffraction measurements on poled PbZr1-xTixO3 (PZT) ceramic samples close to the rhombohedral-tetragonal phase boundary (the so-called morphotropic phase boundary) have shown that for both rhombohedral and 
 High resolution x-ray powder diffraction measurements on poled PbZr1-xTixO3 (PZT) ceramic samples close to the rhombohedral-tetragonal phase boundary (the so-called morphotropic phase boundary) have shown that for both rhombohedral and tetragonal compositions the piezoelectric elongation of the unit cell does not occur along the polar directions but along those directions associated with the monoclinic distortion. This work provides the first direct evidence for the origin of the very high piezoelectricity in PZT.
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Ferroelectricity in Ultrathin Perovskite Films

2004-06-10
Dillon D. Fong , G. B. Stephenson , S. K. Streiffer +4 more
Understanding the suppression of ferroelectricity in perovskite thin films is a fundamental issue that has remained unresolved for decades. We report a synchrotron x-ray study of lead titanate as a 
 Understanding the suppression of ferroelectricity in perovskite thin films is a fundamental issue that has remained unresolved for decades. We report a synchrotron x-ray study of lead titanate as a function of temperature and film thickness for films as thin as a single unit cell. At room temperature, the ferroelectric phase is stable for thicknesses down to 3 unit cells (1.2 nanometers). Our results imply that no thickness limit is imposed on practical devices by an intrinsic ferroelectric size effect.

XCVI. Theory of barium titanate

1949-10-01
A. F. Devonshire
Summary The theory of the dielectric and crystallographic properties of barium titanate is considered. By expanding the free energy as a function of polarization and strain and making reasonable assumptions 
 Summary The theory of the dielectric and crystallographic properties of barium titanate is considered. By expanding the free energy as a function of polarization and strain and making reasonable assumptions about the coefficients, it is found possible to account for the various crystal transitions. Calculations are made of the dielectric constants, crystal stains, internal energy, and self polarization as functions of temperature. Finally relations are obtained between the coefficients in the free energy and the ionic force constants. These are used to estimate some of the coefficients which are not completely determined by experimental data.

Phase transitional behavior and piezoelectric properties of (Na0.5K0.5)NbO3–LiNbO3 ceramics

2004-11-01
Yiping Guo , Ken‐ichi Kakimoto , Hitoshi Ohsato
Lead-free piezoelectric ceramics (1−x)(Na0.5K0.5)NbO3–xLiNbO3 {[Lix(Na0.5K0.5)1−x]NbO3} (x=0.04–0.20) have been synthesized by an ordinary sintering technique. The materials with perovskite structure is orthorhombic phase at xâ©œ0.05 and becomes tetragonal phase at xâ©Ÿ0.07, 
 Lead-free piezoelectric ceramics (1−x)(Na0.5K0.5)NbO3–xLiNbO3 {[Lix(Na0.5K0.5)1−x]NbO3} (x=0.04–0.20) have been synthesized by an ordinary sintering technique. The materials with perovskite structure is orthorhombic phase at xâ©œ0.05 and becomes tetragonal phase at xâ©Ÿ0.07, a phase K3Li2Nb5O15 with tetragonal tungsten bronze structure begins to appear at x=0.08 and becomes dominant with increasing the content of LiNbO3. A morphotropic phase boundary between orthorhombic and tetragonal phases is found in the composition range 0.05&amp;lt;x&amp;lt;0.07. Analogous to Pb(Zr,Ti)O3, the piezoelectric and electromechanical properties are enhanced for compositions near the morphotropic phase boundary. Piezoelectric constant d33 values reach 200–235pC∕N. Electromechanical coefficients of the planar mode and the thickness mode reach 38%–44% and 44%–48%, respectively. The Curie temperatures (TC) of [Lix(Na0.5K0.5)1−x]NbO3 (x=0.04–0.20) are in the range of 452–510°C, at least 100°C higher than that of conventional Pb(Zr,Ti)O3. Our results show that [Lix(Na0.5K0.5)1−x]NbO3 is a good lead-free high-temperature piezoelectric ceramic.

Electronic structure, chemical bonding, and optical properties of paraelectric<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">BaTiO</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

2000-10-01
Sonali Saha , T.P. Sinha , Abhijit Mookerjee
The electronic-energy band structure, site, and angular-momentum decomposed density of states (DOS) and charge-density contours of perovskite ${\mathrm{BaTiO}}_{3}$ in the paraelectric phase are calculated by the first-principles tight-binding linear muffin-tin 
 The electronic-energy band structure, site, and angular-momentum decomposed density of states (DOS) and charge-density contours of perovskite ${\mathrm{BaTiO}}_{3}$ in the paraelectric phase are calculated by the first-principles tight-binding linear muffin-tin orbitals method with the atomic-sphere approximation using density-functional theory in its local-density approximation. The calculated band structure shows a direct band gap of 1.2 eV at the \ensuremath{\Gamma} point in the Brillouin zone. The total DOS is compared to the experimental x-ray photoemission spectrum. From the DOS analysis, as well as charge-density studies, we conclude that the bonding between Ba and ${\mathrm{TiO}}_{3}$ is mainly ionic and that the ${\mathrm{TiO}}_{3}$ entities bond covalently. Using the projected DOS and band structure we have analyzed the interband contribution to the optical properties of ${\mathrm{BaTiO}}_{3}.$ The real and imaginary parts of the dielectric function and hence the optical constants (such as the reflectivity, refractive index, extinction coefficient, absorption coefficient, and the electron energy-loss spectrum) are calculated. The calculated spectra are compared with the experimental results for ${\mathrm{BaTiO}}_{3}$ at room temperature in the ferroelectric phase and are found to be in good agreement with the experimental data in the low-energy regions. The role of band-structure calculation as regards the optical properties of ${\mathrm{BaTiO}}_{3}$ is discussed.

Giant Electrocaloric Effect in Thin-Film PbZr <sub>0.95</sub> Ti <sub>0.05</sub> O <sub>3</sub>

2006-03-02
A. S. Mischenko , Qi Zhang , J. F. Scott +2 more
An applied electric field can reversibly change the temperature of an electrocaloric material under adiabatic conditions, and the effect is strongest near phase transitions. We demonstrate a giant electrocaloric effect 
 An applied electric field can reversibly change the temperature of an electrocaloric material under adiabatic conditions, and the effect is strongest near phase transitions. We demonstrate a giant electrocaloric effect (0.48 kelvin per volt) in 350-nanometer PbZr(0.95)Ti(0.05)O3 films near the ferroelectric Curie temperature of 222 degrees C. A large electrocaloric effect may find application in electrical refrigeration.
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Lead-free piezoelectric ceramics: Alternatives for PZT?

2007-02-23
Thomas R. Shrout , Shujun Zhang

Effect of Mechanical Boundary Conditions on Phase Diagrams of Epitaxial Ferroelectric Thin Films

1998-03-02
N. A. Pertsev , A. G. Zembilgotov , A. K. Tagantsev
A phenomenological thermodynamic theory of ferroelectric thin films epitaxially grown on cubic substrates is developed using a new form of the thermodynamic potential, which corresponds to the actual mechanical boundary 
 A phenomenological thermodynamic theory of ferroelectric thin films epitaxially grown on cubic substrates is developed using a new form of the thermodynamic potential, which corresponds to the actual mechanical boundary conditions of the problem. For single-domain ${\mathrm{BaTiO}}_{3}$ and ${\mathrm{PbTiO}}_{3}$ films, the ``misfit-temperature'' phase diagrams are constructed. It is found that the 2D clamping of the films, apart from a shift of the temperature of the ferroelectric transition, results in a change of its order. A change of the sequence of the phases and the appearance of phases forbidden in the bulk crystals are predicted.

Physics of thin-film ferroelectric oxides

2005-10-17
Matthew Dawber , Karin M. Rabe , J. F. Scott
This review covers the important advances in recent years in the physics of thin film ferroelectric oxides, the strongest emphasis being on those aspects particular to ferroelectrics in thin film 
 This review covers the important advances in recent years in the physics of thin film ferroelectric oxides, the strongest emphasis being on those aspects particular to ferroelectrics in thin film form. We introduce the current state of development in the application of ferroelectric thin films for electronic devices and discuss the physics relevant for the performance and failure of these devices. Following this we cover the enormous progress that has been made in the first principles computational approach to understanding ferroelectrics. We then discuss in detail the important role that strain plays in determining the properties of epitaxial thin ferroelectric films. Finally, we look at the emerging possibilities for nanoscale ferroelectrics, with particular emphasis on ferroelectrics in non conventional nanoscale geometries.
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Domain Formation and Domain Wall Motions in Ferroelectric BaTi<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">O</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>Single Crystals

1954-08-01
Walter J. Merz
The nucleation and growth of ferroelectric domains in barium titanate have been studied as a function of applied electric field and temperature. The optical and electrical measurements were made on 
 The nucleation and growth of ferroelectric domains in barium titanate have been studied as a function of applied electric field and temperature. The optical and electrical measurements were made on thin single-crystal plates normal to $c$, the polar direction. When the electric field applied along this direction is reversed, new domains with opposite polarization are formed. The manner of growth of these domains is very different from that of domain growth in ferromagnetic materials. The sidewise motion of the 180\ifmmode^\circ\else\textdegree\fi{} side walls (walls between domains with antiparallel polarization) which is common in ferromagnetic crystals is almost never found in barium titanate. Instead its polarization is changed by the formation of very many new anti-parallel domains which are extremely thin (${10}^{\ensuremath{-}4}$ cm) and appear to grow only in the forward direction. The explanation of this behavior is found in the weak coupling between the dipoles perpendicular to the dipole direction. The wall thickness is small, of the order of one to a few lattice constants; the wall energy in BaTi${\mathrm{O}}_{3}$ is of the order of 10 erg/${\mathrm{cm}}^{2}$. Electrical pulsing experiments substantiate the optical observations very clearly. Pulsing the samples at different temperatures shows that the nucleation rate of new domains is accelerated at elevated temperatures. Furthermore, the growth of the new domains is faster at higher temperatures. Experimental results are presented showing how the switching current and the switching time depend on applied electrical field, on temperature, and on the size of the sample.

Connectivity and piezoelectric-pyroelectric composites

1978-05-01
Robert E. Newnham , Doyle P. Skinner , L. E. Cross

Critical thickness for ferroelectricity in perovskite ultrathin films

2003-04-01
Javier Junquera , Philippe Ghosez

Impedance and modulus spectroscopy of semiconducting BaTiO3 showing positive temperature coefficient of resistance

1989-10-15
Derek C. Sinclair , Anthony R. West
Polycrystalline barium titanate that has been doped to give a positive temperature coefficient of resistance (PTCR) effect is an inhomogeneous material electrically. Analysis of ac impedance data using the complex 
 Polycrystalline barium titanate that has been doped to give a positive temperature coefficient of resistance (PTCR) effect is an inhomogeneous material electrically. Analysis of ac impedance data using the complex impedance plane representation gives the dc resistance of PTCR ceramics. By additional use of the complex electric modulus formalism to analyze the same data, the inhomogeneous nature of the ceramics may be probed. This reveals the presence of two, sometimes three elements in the equivalent circuit. Grain-boundary and bulk effects may be distinguished from capacitance data: grain-boundary effects have temperature-independent capacitances, whereas bulk effects show a capacitance maximum at the Curie point and Curie–Weiss behavior above the Curie point. Both grain-boundary and bulk effects appear to contribute to the PTCR effect. These results reveal limitations in current theories of the PTCR effect.

The Physics of Ferroelectric Memories

1998-07-01
Orlando Auciello , J. F. Scott , R. Ramesh
Imagine you are in the last stages of typing your thesis, the year is 1980, and it's a hot, hazy summer afternoon, a thunderstorm brews on the horizon. Tense and 
 Imagine you are in the last stages of typing your thesis, the year is 1980, and it's a hot, hazy summer afternoon, a thunderstorm brews on the horizon. Tense and tired, you have forgotten to save the document on your hard disk. Suddenly, lightning strikes! Your computer shuts down. Your final chapter is lost.

Large electric-field-induced strain in ferroelectric crystals by point-defect-mediated reversible domain switching

2004-01-11
Xiaobing Ren

Origin of ferroelectricity in perovskite oxides

1992-07-01
R. E. Cohen

Domain wall nanoelectronics

2012-02-03
Gustau CatalĂĄn , Jan Seidel , R. Ramesh +1 more
Domains in ferroelectrics were considered to be well understood by the middle of the last century: They were generally rectilinear, and their walls were Ising-like. Their simplicity stood in stark 
 Domains in ferroelectrics were considered to be well understood by the middle of the last century: They were generally rectilinear, and their walls were Ising-like. Their simplicity stood in stark contrast to the more complex Bloch walls or N\'eel walls in magnets. Only within the past decade and with the introduction of atomic-resolution studies via transmission electron microscopy, electron holography, and atomic force microscopy with polarization sensitivity has their real complexity been revealed. Additional phenomena appear in recent studies, especially of magnetoelectric materials, where functional properties inside domain walls are being directly measured. In this paper these studies are reviewed, focusing attention on ferroelectrics and multiferroics but making comparisons where possible with magnetic domains and domain walls. An important part of this review will concern device applications, with the spotlight on a new paradigm of ferroic devices where the domain walls, rather than the domains, are the active element. Here magnetic wall microelectronics is already in full swing, owing largely to the work of Cowburn and of Parkin and their colleagues. These devices exploit the high domain wall mobilities in magnets and their resulting high velocities, which can be supersonic, as shown by Kreines' and co-workers 30 years ago. By comparison, nanoelectronic devices employing ferroelectric domain walls often have slower domain wall speeds, but may exploit their smaller size as well as their different functional properties. These include domain wall conductivity (metallic or even superconducting in bulk insulating or semiconducting oxides) and the fact that domain walls can be ferromagnetic while the surrounding domains are not.
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Large Piezoelectric Effect in Pb-Free Ceramics

2009-12-15
Wenfeng Liu , Xiaobing Ren
We report a non-Pb piezoelectric ceramic system Ba(Ti(0.8)Zr(0.2))O(3)-(Ba(0.7)Ca(0.3))TiO(3) which shows a surprisingly high piezoelectric coefficient of d(33) approximately 620 pC/N at optimal composition. Its phase diagram shows a morphotropic phase 
 We report a non-Pb piezoelectric ceramic system Ba(Ti(0.8)Zr(0.2))O(3)-(Ba(0.7)Ca(0.3))TiO(3) which shows a surprisingly high piezoelectric coefficient of d(33) approximately 620 pC/N at optimal composition. Its phase diagram shows a morphotropic phase boundary (MPB) starting from a tricritical triple point of a cubic paraelectric phase (C), ferroelectric rhombohedral (R), and tetragonal (T) phases. The high piezoelectricity of the MPB compositions stems from the composition proximity of the MPB to the tricritical triple point, which leads to a nearly vanishing polarization anisotropy and thus facilitates polarization rotation between 001T and 111R states. We predict that the single-crystal form of the MPB composition of the present system may reach a giant d(33) = 1500-2000 pC/N. Our work may provide a new recipe for designing highly piezoelectric materials (both Pb-free and Pb-containing) by searching MPBs starting from a TCP.
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Lanthanum-substituted bismuth titanate for use in non-volatile memories

1999-10-01
Bae Ho Park , Bo Soo Kang , Sang Don Bu +3 more

Freezing of the polarization fluctuations in lead magnesium niobate relaxors

1990-09-15
D. Viehland , S. J. Jang , L. E. Cross +1 more
The dielectric relaxation of a solid solution of 10-mol % lead titanate in lead magnesium niobate is found to be similar to the magnetic relaxation in spin-glass systems.1–3 Based on 
 The dielectric relaxation of a solid solution of 10-mol % lead titanate in lead magnesium niobate is found to be similar to the magnetic relaxation in spin-glass systems.1–3 Based on this analogy, it is proposed that the relaxor ferroelectric is a polar-glassy system which has thermally activated polarization fluctuations above a static freezing temperature. An activation energy and freezing temperature of 0.0407 eV and 291.5 K, respectively, were found by analyzing the frequency dependence of the temperature of the dielectric maximum using the Vogel–Fulcher relationship.4,5 It has also been shown that a macroscopic polarization is sustained on heating up to this freezing temperature. A coupling between nanometer scale clusters is believed to control the kinetics of the fluctuations and the development of a frustration as the system freezes into states of local equilibrium. The possibility of an orientational freezing associated with the ferroelastic nature of the nanosized polar regions in the rhombohedral relaxor families as well as a polar freezing is discussed. A diffuse phase transformation is believed to arise due to a dispersion in the fluctuation frequency of the polarization. A qualitative model for the relaxation time spectrum is also proposed in which the width of the spectrum broadens strongly near the freezing temperature.

Perspective on the Development of Lead‐free Piezoceramics

2009-05-21
JĂŒrgen Rödel , Wook Jo , Klaus T. P. Seifert +3 more
A large body of work has been reported in the last 5 years on the development of lead‐free piezoceramics in the quest to replace lead–zirconate–titanate (PZT) as the main material 
 A large body of work has been reported in the last 5 years on the development of lead‐free piezoceramics in the quest to replace lead–zirconate–titanate (PZT) as the main material for electromechanical devices such as actuators, sensors, and transducers. In specific but narrow application ranges the new materials appear adequate, but are not yet suited to replace PZT on a broader basis. In this paper, general guidelines for the development of lead‐free piezoelectric ceramics are presented. Suitable chemical elements are selected first on the basis of cost and toxicity as well as ionic polarizability. Different crystal structures with these elements are then considered based on simple concepts, and a variety of phase diagrams are described with attractive morphotropic phase boundaries, yielding good piezoelectric properties. Finally, lessons from density functional theory are reviewed and used to adjust our understanding based on the simpler concepts. Equipped with these guidelines ranging from atom to phase diagram, the current development stage in lead‐free piezoceramics is then critically assessed.

Room-temperature ferroelectricity in strained SrTiO3

2004-08-01
J. H. Haeni , Patrick Irvin , Wontae Chang +7 more
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Applications of Modern Ferroelectrics

2007-02-15
J. F. Scott
Long viewed as a topic in classical physics, ferroelectricity can be described by a quantum mechanical ab initio theory. Thin-film nanoscale device structures integrated onto Si chips have made inroads 
 Long viewed as a topic in classical physics, ferroelectricity can be described by a quantum mechanical ab initio theory. Thin-film nanoscale device structures integrated onto Si chips have made inroads into the semiconductor industry. Recent prototype applications include ultrafast switching, cheap room-temperature magnetic-field detectors, piezoelectric nanotubes for microfluidic systems, electrocaloric coolers for computers, phased-array radar, and three-dimensional trenched capacitors for dynamic random access memories. Terabit-per-square-inch ferroelectric arrays of lead zirconate titanate have been reported on Pt nanowire interconnects and nanorings with 5-nanometer diameters. Finally, electron emission from ferroelectrics yields cheap, high-power microwave devices and miniature x-ray and neutron sources.

Transferring lead-free piezoelectric ceramics into application

2015-01-09
JĂŒrgen Rödel , Kyle G. Webber , Robert Dittmer +3 more

Fatigue-free ferroelectric capacitors with platinum electrodes

1995-04-01
C. A-Paz de Araujo , J. D. Cuchiaro , L. D. McMillan +2 more

Caloric materials near ferroic phase transitions

2014-04-22
Xavier Moya , Sohini Kar‐Narayan , N. D. Mathur
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The perovskite structure—a review of its role in ceramic science and technology

2000-11-01
A. S. Bhalla , Ruyan Guo , Rustum Roy
AbstractStarting with the history of the fundamental science of the relation of structure to composition delineated completely by Goldschmidt, we use the perovskite structure to illustrate the enormous power of 
 AbstractStarting with the history of the fundamental science of the relation of structure to composition delineated completely by Goldschmidt, we use the perovskite structure to illustrate the enormous power of crystal chemistry-based intelligent synthesis in creating new materials.The perovskite structure is shown to be the single most versatile ceramic host. By appropriate changes in composition one can modify the most significant electro- ceramic dielectric (BaTiO3 and its relatives) phase in industry, into metallic conductors, superconductors or the highest pressure phases in the earth. After an historical introduction of the science, detailed treatment of the applications is confined to the most recent research on novel uses in piezoelectric, ferroelectric and related applications.Keywords: PerovskiteCrystal-chemistryTolerance factorFerroicsElectro-ceramics

Potassium–Sodium Niobate Lead-Free Piezoelectric Materials: Past, Present, and Future of Phase Boundaries

2015-03-20
Jiagang Wu , Dingquan Xiao , Jianguo Zhu
ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTPotassium–Sodium Niobate Lead-Free Piezoelectric Materials: Past, Present, and Future of Phase BoundariesJiagang Wu*, Dingquan Xiao, and Jianguo ZhuView Author Information Department of Materials Science, Sichuan University, Chengdu 
 ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTPotassium–Sodium Niobate Lead-Free Piezoelectric Materials: Past, Present, and Future of Phase BoundariesJiagang Wu*, Dingquan Xiao, and Jianguo ZhuView Author Information Department of Materials Science, Sichuan University, Chengdu 610064, China*E-mail:[email protected] and [email protected]Cite this: Chem. Rev. 2015, 115, 7, 2559–2595Publication Date (Web):March 20, 2015Publication History Received1 December 2014Published online20 March 2015Published inissue 8 April 2015https://doi.org/10.1021/cr5006809Copyright © 2015 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views13354Altmetric-Citations1127LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (14 MB) Get e-AlertsSUBJECTS:Ceramics,Electrical properties,Materials,Piezoelectrics,Sintering Get e-Alerts

Two‐Dimensional Dielectric Nanosheets: Novel Nanoelectronics From Nanocrystal Building Blocks

2011-10-14
Minoru Osada , Takayoshi Sasaki
Abstract Two‐dimensional (2D) nanosheets, which possess atomic or molecular thickness and infinite planar lengths, are regarded as the thinnest functional nanomaterials. The recent development of methods for manipulating graphene (carbon 
 Abstract Two‐dimensional (2D) nanosheets, which possess atomic or molecular thickness and infinite planar lengths, are regarded as the thinnest functional nanomaterials. The recent development of methods for manipulating graphene (carbon nanosheet) has provided new possibilities and applications for 2D systems; many amazing functionalities such as high electron mobility and quantum Hall effects have been discovered. However, graphene is a conductor, and electronic technology also requires insulators, which are essential for many devices such as memories, capacitors, and gate dielectrics. Along with graphene, inorganic nanosheets have thus increasingly attracted fundamental research interest because they have the potential to be used as dielectric alternatives in next‐generation nanoelectronics. Here, we review the progress made in the properties of dielectric nanosheets, highlighting emerging functionalities in electronic applications. We also present a perspective on the advantages offered by this class of materials for future nanoelectronics.
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Large Electrocaloric Effect in Ferroelectric Polymers Near Room Temperature

2008-08-07
Bret Neese , Baojin Chu , Sheng-Guo Lu +3 more
Applying an electrical field to a polar polymer may induce a large change in the dipolar ordering, and if the associated entropy changes are large, they can be explored in 
 Applying an electrical field to a polar polymer may induce a large change in the dipolar ordering, and if the associated entropy changes are large, they can be explored in cooling applications. With the use of the Maxwell relation between the pyroelectric coefficient and the electrocaloric effect (ECE), it was determined that a large ECE can be realized in the ferroelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymer at temperatures above the ferroelectric-paraelectric transition (above 70 degrees C), where an isothermal entropy change of more than 55 joules per kilogram per kelvin degree and adiabatic temperature change of more than 12 degrees C were observed. We further showed that a similar level of ECE near room temperature can be achieved by working with the relaxor ferroelectric polymer of P(VDF-TrFE-chlorofluoroethylene).

Base-Metal Electrode-Multilayer Ceramic Capacitors: Past, Present and Future Perspectives

2003-01-15
Hiroshi Kishi , Youichi Mizuno , Hirokazu Chazono
Multilayer ceramic capacitor (MLCC) production and sales figures are the highest among fine-ceramic products developed in the past 30 years. The total worldwide production and sales reached 550 billion pieces 
 Multilayer ceramic capacitor (MLCC) production and sales figures are the highest among fine-ceramic products developed in the past 30 years. The total worldwide production and sales reached 550 billion pieces and 6 billion dollars, respectively in 2000. In the course of progress, the development of base-metal electrode (BME) technology played an important role in expanding the application area. In this review, the recent progress in MLCCs with BME nickel (Ni) electrodes is reviewed from the viewpoint of nonreducible dielectric materials. Using intermediate-ionic-size rare-earth ion (Dy2O3, Ho2O3, Er2O3, Y2O3) doped BaTiO3 (ABO3)-based dielectrics, highly reliable Ni-MLCCs with a very thin layer below 2 ”m in thickness have been developed. The effect of site occupancy of rare-earth ions in BaTiO3 on the electrical properties and microstructure of nonreducible dielectrics is studied systematically. It appears that intermediate-ionic-size rare-earth ions occupy both A- and B-sites in the BaTiO3 lattice and effectively control the donor/acceptor dopant ratio and microstructural evolution. The relationship between the electrical properties and the microstructure of Ni-MLCCs is also presented.
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Lead-free piezoceramics

2004-10-31
Yasuyoshi Saito , Hisaaki Takao , Toshihiko Tani +5 more

Fabrication of perovskite lead magnesium niobate

1982-10-01
Scott Swartz , Thomas R. Shrout

Ultrahigh strain and piezoelectric behavior in relaxor based ferroelectric single crystals

1997-08-15
Seung-Eek Park , Thomas R. Shrout
Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite 
 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Seung-Eek Park, Thomas R. Shrout; Ultrahigh strain and piezoelectric behavior in relaxor based ferroelectric single crystals. Journal of Applied Physics 15 August 1997; 82 (4): 1804–1811. https://doi.org/10.1063/1.365983 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioJournal of Applied Physics Search Advanced Search |Citation Search

Ferroelectric Ceramics: History and Technology

1999-04-01
Gene H. Haertling
Ferroelectric ceramics were born in the early 1940s with the discovery of the phenomenon of ferroelectricity as the source of the unusually high dielectric constant in ceramic barium titanate capacitors. 
 Ferroelectric ceramics were born in the early 1940s with the discovery of the phenomenon of ferroelectricity as the source of the unusually high dielectric constant in ceramic barium titanate capacitors. Since that time, they have been the heart and soul of several multibillion dollar industries, ranging from high‐dielectric‐constant capacitors to later developments in piezoelectric transducers, positive temperature coefficient devices, and electrooptic light valves. Materials based on two compositional systems, barium titanate and lead zirconate titanate, have dominated the field throughout their history. The more recent developments in the field of ferroelectric ceramics, such as medical ultrasonic composites, high‐displacement piezoelectric actuators (Moonies, RAINBOWS), photostrictors, and thin and thick films for piezoelectric and integrated‐circuit applications have served to keep the industry young amidst its growing maturity. Various ceramic formulations, their form (bulk, films), fabrication, function (properties), and future are described in relation to their ferroelectric nature and specific areas of application.

Strain Tuning of Ferroelectric Thin Films

2007-06-25
Darrell G. Schlom , Long‐Qing Chen , Chang‐Beom Eom +3 more
Predictions and measurements of the effect of biaxial strain on the properties of epitaxial ferroelectric thin films and superlattices are reviewed. Results for single-layer ferroelectric films of biaxially strained SrTiO 
 Predictions and measurements of the effect of biaxial strain on the properties of epitaxial ferroelectric thin films and superlattices are reviewed. Results for single-layer ferroelectric films of biaxially strained SrTiO 3 , BaTiO 3 , and PbTiO 3 as well as PbTiO 3 /SrTiO 3 and BaTiO 3 /SrTiO 3 superlattices are described. Theoretical approaches, including first principles, thermodynamic analysis, and phase-field models, are applied to these biaxially strained materials, the assumptions and limitations of each technique are explained, and the predictions are compared. Measurements of the effect of biaxial strain on the paraelectric-to-ferroelectric transition temperature (T C ) are shown, demonstrating the ability of percent-level strains to shift T C by hundreds of degrees in agreement with the predictions that predated such experiments. Along the way, important experimental techniques for characterizing the properties of strained ferroelectric thin films and superlattices, as well as appropriate substrates on which to grow them, are mentioned.

Recent progress in relaxor ferroelectrics with perovskite structure

2006-01-01
Alexei A. Bokov , Zuo‐Guang Ye

Relaxorferroelectrics: An overview

1994-01-01
L. E. Cross
Abstract The paper will trace the evolution of understanding related to the modification of sharp ferroelectric phase transition behavior that occurs in composition systems which exhibit diffuse and relaxor ferroelectric 
 Abstract The paper will trace the evolution of understanding related to the modification of sharp ferroelectric phase transition behavior that occurs in composition systems which exhibit diffuse and relaxor ferroelectric properties. The focus will be primarily upon the perovskite structure families where cations of different valence occupying similar crystallographic sites in the structure appear to play an important role. Limited ordering in the Pb(B1B2)O3 systems will be discussed and possible mechanisms for self limiting to nanometer scales in some systems explored. New studies of the break up of the simple ferroelectric behavior in lanthanum modified lead zirconate titanate (PLZT) and in lead titanate (PLT) systems will be discussed and the relevance to the general problem of relaxor behavior examined. Evidence for enhanced polarization fluctuations and super paraelectric behavior at high temperatures will be discussed and random field and spin glass models for the lower temperature state considered. In the tungsten bronze structure relaxors barium strontium niobate (SBN) and lead barium niobate (PBN) the behavior is more complex suggesting the possibility for relaxor behavior in directions orthogonal to existing polarization systems.

Enhancement of Ferroelectricity in Strained BaTiO <sub>3</sub> Thin Films

2004-11-04
Kyoung Jin Choi , Michael D. Biegalski , Yulan Li +7 more
Biaxial compressive strain has been used to markedly enhance the ferroelectric properties of BaTiO3 thin films. This strain, imposed by coherent epitaxy, can result in a ferroelectric transition temperature nearly 
 Biaxial compressive strain has been used to markedly enhance the ferroelectric properties of BaTiO3 thin films. This strain, imposed by coherent epitaxy, can result in a ferroelectric transition temperature nearly 500 degrees C higher and a remanent polarization at least 250% higher than bulk BaTiO3 single crystals. This work demonstrates a route to a lead-free ferroelectric for nonvolatile memories and electro-optic devices.

Dielectric properties of fine-grained barium titanate ceramics

1985-08-15
G. Arlt , Detlev Hennings , Gijsbertus de With
Dielectric properties, lattice- and microstructure of ceramic BaTiO3 showing grain sizes of 0.3–100 ÎŒm were studied. At grain sizes &amp;lt;10 ÎŒm the width of ferroelectric 90° domains decreases proportionally to 
 Dielectric properties, lattice- and microstructure of ceramic BaTiO3 showing grain sizes of 0.3–100 ÎŒm were studied. At grain sizes &amp;lt;10 ÎŒm the width of ferroelectric 90° domains decreases proportionally to the square root of the grain diameter. The decreasing width of the domains can be theoretically explained by the equilibrium of elastic field energy and domain wall energy. The smaller the grains, the more the dielectric and the elastic constants are determined by the contribution of 90° domain walls. The permittivity below the Curie point shows a pronounced maximum Δr ≊5000 at grain sizes 0.8–1 ÎŒm. At grain sizes &amp;lt;0.7 ÎŒm the permittivity strongly decreases and the lattice gradually changes from tetragonal to pseudocubic.
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SrTi<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">O</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>: An intrinsic quantum paraelectric below 4 K

1979-04-01
K. A. MĂŒller , H. Burkard
The dielectric constants ${\ensuremath{\epsilon}}_{〈110〉}$ and their change with uniaxial $〈1\overline{1}0〉$ stress in monodomain $〈001〉$SrTi${\mathrm{O}}_{3}$ samples have been measured as a function of temperature. Between 4 K and 0.3 K these 
 The dielectric constants ${\ensuremath{\epsilon}}_{〈110〉}$ and their change with uniaxial $〈1\overline{1}0〉$ stress in monodomain $〈001〉$SrTi${\mathrm{O}}_{3}$ samples have been measured as a function of temperature. Between 4 K and 0.3 K these quantities are independent of temperature. In one sample $\ensuremath{\epsilon}(T)$ was measured to 0.035 K and found to be constant. This proves the quantum-mechanical stabilization of the paraelectric phase below 4 K with a very high dielectric constant $\ensuremath{\epsilon}$. The crossover from classical to quantum behavior on lowering the temperature is discussed, and it is shown that the coupling of the ferroelectric mode to acoustic ones is important. The $\ensuremath{\epsilon}(T)$ dependence is compared to earlier and recent theories. The former, yielding a coth ($\frac{\ensuremath{\hbar}\ensuremath{\Omega}}{\mathrm{kT}}$) term, are found to be inadequate for the crossover region. A recent biquadratic ferroelectric mode-coupling theory fits the data better.

Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics

1998-09-01
Dragan Damjanović
Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics are reviewed with the aim of providing an insight into different processes which may affect the behaviour of ferroelectric 
 Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics are reviewed with the aim of providing an insight into different processes which may affect the behaviour of ferroelectric devices, such as ferroelectric memories and micro-electro-mechanical systems. Taking into consideration recent advances in this field, topics such as polarization switching, polarization fatigue, effects of defects, depletion layers, and depolarization fields on hysteresis loop behaviour, and contributions of domain-wall displacement to dielectric and piezoelectric properties are discussed. An introduction into dielectric, pyroelectric, piezoelectric and elastic properties of ferroelectric materials, symmetry considerations, coupling of electro-mechanical and thermal properties, and definitions of relevant ferroelectric phenomena are provided.

Decoding the Fingerprint of Ferroelectric Loops: Comprehension of the Material Properties and Structures

2013-12-17
Li Jin , Fei Li , Shujun Zhang
Due to the nature of domains, ferroics, including ferromagnetic, ferroelectric, and ferroelastic materials, exhibit hysteresis phenomena with respect to external driving fields (magnetic field, electric field, or stress). In principle, 
 Due to the nature of domains, ferroics, including ferromagnetic, ferroelectric, and ferroelastic materials, exhibit hysteresis phenomena with respect to external driving fields (magnetic field, electric field, or stress). In principle, every ferroic material has its own hysteresis loop, like a fingerprint, which contains information related to its properties and structures. For ferroelectrics, many characteristic parameters, such as coercive field, spontaneous, and remnant polarizations can be directly extracted from the hysteresis loops. Furthermore, many impact factors, including the effect of materials (grain size and grain boundary, phase and phase boundary, doping, anisotropy, thickness), aging (with and without poling), and measurement conditions (applied field amplitude, fatigue, frequency, temperature, stress), can affect the hysteretic behaviors of the ferroelectrics. In this feature article, we will first give the background of the ferroic materials and multiferroics, with an emphasis on ferroelectrics. Then it is followed by an introduction of the characterizing techniques for the loops, including the polarization–electric field loops and strain–electric field curves. A caution is made to avoid misinterpretation of the loops due to the existence of conductivity. Based on their morphologic features, the hysteresis loops are categorized to four groups and the corresponding material usages are introduced. The impact factors on the hysteresis loops are discussed based on recent developments in ferroelectric and related materials. It is suggested that decoding the fingerprint of loops in ferroelectrics is feasible and the comprehension of the material properties and structures through the hysteresis loops is established.

Intrinsic and Extrinsic Size Effects in Fine‐Grained Morphotropic‐Phase‐Boundary Lead Zirconate Titanate Ceramics

1998-03-01
Clive A. Randall , Namchul Kim , John‐Paul Kucera +2 more
The processing, electromechanical properties, and microstructure of lead zirconate titanate (PZT) ceramics over the grain‐size range of 0.1‐10 ÎŒm were studied. Using measurements over a large temperature range (15‐600 K), 
 The processing, electromechanical properties, and microstructure of lead zirconate titanate (PZT) ceramics over the grain‐size range of 0.1‐10 ÎŒm were studied. Using measurements over a large temperature range (15‐600 K), the relative role of extrinsic contribution (i.e., domain‐wall motion) was deduced to be influenced strongly by the grain size, particularly for donor‐doped PZT. Analytical transmission electron microscopy studies were conducted to investigate the trend in domain configurations with the reduction of grain size. The correlations between domain density, domain variants, domain configurations (before and after poling), spontaneous deformation, and the elastodielectric properties were qualitatively discussed, leading to new insights into the intrinsic and extrinsic effects and relevant size effects in ferroelectric polycrystalline materials.

Critical exponents of the dielectric constants in diffused-phase-transition crystals

1982-04-01
Kenji Uchino , Shƍichiro Nomura
Abstract The critical exponent Îł in the relation between the dielectric constant and temperature (1/Δ—1/Δm = C'-1x (T—Tm)Îł) has been determined precisely for relaxor ferroelectrlics Pb(Mg1/3Nb2/3)O3, Pb(Zn1/3 Nb2/3)O3 and a 
 Abstract The critical exponent Îł in the relation between the dielectric constant and temperature (1/Δ—1/Δm = C'-1x (T—Tm)Îł) has been determined precisely for relaxor ferroelectrlics Pb(Mg1/3Nb2/3)O3, Pb(Zn1/3 Nb2/3)O3 and a related solid solution 0.88Pb (Zn1/3 Nb2/3)O3-0. I2PbT103, as well as for normal ferroelectrics BaTiO3 and K(Ta0. 55Nb0.45)O3. A high correlation of the Îł value with the plase transition diffuseness has been found empirically. Moreover, this Îł value is very close to another critical exponent Îł* which is defined in the relation between the dielectric constant and hydrostatic pressure (1/Δ—1/Δm = C* (p—pm)Îł*)

(Bi<sub>1/2</sub>Na<sub>1/2</sub>)TiO<sub>3</sub>-BaTiO<sub>3</sub> System for Lead-Free Piezoelectric Ceramics

1991-09-01
Tadashi Takenaka , Kei-ichi Maruyama Kei-ichi Maruyama , Koichiro Sakata Koichiro Sakata
One of the (Bi 1/2 Na 1/2 )TiO 3 (BNT)-based solid solutions, Ba-modified bismuth sodium titanate, (Bi 1/2 Na 1/2 ) 1- x Ba x TiO 3 (BNBT), is studied 
 One of the (Bi 1/2 Na 1/2 )TiO 3 (BNT)-based solid solutions, Ba-modified bismuth sodium titanate, (Bi 1/2 Na 1/2 ) 1- x Ba x TiO 3 (BNBT), is studied for its dielectric and piezoelectric properties as a new group of lead-free piezoelectric ceramics. A rhombohedral (F α )-tetragonal (F ÎČ ) morphotropic phase boundary (MPB) is shown to exist at x =0.06∌0.07 by X-ray data, and dielectric and piezoelectric properties. BNBT ceramics with the MPB composition are superior as piezoelectric ceramics in high-frequency ultrasonic applications or as piezoelectric actuator materials because of a lower free permittivity, Δ 33 T /Δ 0 , and a high electromechanical coupling factor, k t or k 33 , along with high mechanical strength.

BaTiO3-based piezoelectrics: Fundamentals, current status, and perspectives

2017-12-01
Matias Acosta , Nikola Novak , VerĂłnica GarcĂ­a +5 more
We present a critical review that encompasses the fundamentals and state-of-the-art knowledge of barium titanate-based piezoelectrics. First, the essential crystallography, thermodynamic relations, and concepts necessary to understand piezoelectricity and ferroelectricity 
 We present a critical review that encompasses the fundamentals and state-of-the-art knowledge of barium titanate-based piezoelectrics. First, the essential crystallography, thermodynamic relations, and concepts necessary to understand piezoelectricity and ferroelectricity in barium titanate are discussed. Strategies to optimize piezoelectric properties through microstructure control and chemical modification are also introduced. Thereafter, we systematically review the synthesis, microstructure, and phase diagrams of barium titanate-based piezoelectrics and provide a detailed compilation of their functional and mechanical properties. The most salient materials treated include the (Ba,Ca)(Zr,Ti)O3, (Ba,Ca)(Sn,Ti)O3, and (Ba,Ca)(Hf,Ti)O3 solid solution systems. The technological relevance of barium titanate-based piezoelectrics is also discussed and some potential market indicators are outlined. Finally, perspectives on productive lines of future research and promising areas for the applications of these materials are presented.
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Ultrahigh piezoelectricity in ferroelectric ceramics by design

2018-03-19
Fei Li , Dabin Lin , Zibin Chen +7 more

Perovskite lead-free dielectrics for energy storage applications

2018-12-23
Letao Yang , Xi Kong , Fei Li +5 more

Relaxor ferroelectrics

1987-12-01
L. E. Cross
This article attempts to review a number of macroscopic measurements which have been used to explore the electrical, mechanical, thermal, and optical characteristics of relaxor ferroelectrics and to authenticate the 
 This article attempts to review a number of macroscopic measurements which have been used to explore the electrical, mechanical, thermal, and optical characteristics of relaxor ferroelectrics and to authenticate the compositional heterogeneity model which was first proposed by G.A. Smolenskii to describe these materials. In this connection the work of N. Setter on order disorder in lead scandium tantate is discussed to clearly establish the role of compositional heterogeneity. To demonstrate the very wide temperature range above the dielectric permittivity maximum Tm over which large values of RMS polarization persists, electrostrictive spontaneous strain and quadratic electro-optic measurements on lead magnesium niobate and on the tungsten bronze structure ferroelectric barium strontium niobate are introduced. In order to validate the hypothesis that the polar micro regions which exist above Tm are in dynamical disorder, measurements of the field induced electrostriction are reviewed. From the aging behavior of suitably doped relaxor compositions it is suggested that because of internal heterogeneity local and global symmetries differ in the relaxor and the consequences of these differences are discussed with respect to the poling: depoling behavior and to the low temperature dispersion in lead barium niobate bronze structures.

In‐Situ Heating X‐Ray Diffraction of LiNi<sub>0.6</sub>Mn<sub>0.3</sub>Co<sub>0.1</sub>O<sub>2</sub> and LiNi<sub>0.7</sub>Mn<sub>0.3</sub>O<sub>2</sub> Made Using the All‐Dry Synthesis Process

2025-06-25
Svena Yu , Toby Bond , Al Rahemtulla +3 more | Small Methods
Abstract In‐situ synthesis X‐ray diffraction is conducted at the Canadian Light Source to probe phase changes during the all‐dry synthesis of LiNi 0.6 Mn 0.3 Co 0.1 O 2 (NMC631) 
 Abstract In‐situ synthesis X‐ray diffraction is conducted at the Canadian Light Source to probe phase changes during the all‐dry synthesis of LiNi 0.6 Mn 0.3 Co 0.1 O 2 (NMC631) and LiNi 0.7 Mn 0.3 O 2 (NM73) made using either LiOH·H 2 O or Li 2 CO 3 . All materials are heated up to 950 °C and held for one hour at 950 °C under flowing oxygen. The pathway to a layered phase is similar for all samples. First, a lithiated manganese oxide phase is formed at low temperature, then cations are incorporated into a rock salt phase from ≈420 °C. A spinel intermediary phase is formed before cation ordering occurs between Li and transition metal ions above 800 °C, giving rise to the intended layered hexagonal structure. Amongst the three materials tested, the layered phase of NMC631 (made using LiOH·H 2 O) evolves at the lowest temperature of ≈820 °C and refines rapidly during the high temperature hold. The melting of LiOH coincides nicely with the oxidation of Ni, which forms the basis for the rock salt structure. It is postulated that the molten LiOH facilitates cation diffusion into the rock salt phase, allowing for an earlier formation of the layered phase in comparison to using Li 2 CO 3 , which has a higher decomposition temperature.

Strong anharmonicity dictates ultralow thermal conductivities of type-I clathrates

2025-06-25
NULL AUTHOR_ID | Physical review. B./Physical review. B

Effect of Stoichiometry on the Structure and Polarization of BaTiO<sub>3</sub>

2025-06-24
Ashley Cavanagh , Larissa B. Little , Yang Zhang +7 more | Advanced Optical Materials
Abstract Barium titanate (BaTiO 3 ) is a material of interest for photonic device applications due to its strong optical non‐linearity. However, BaTiO 3 ‐based devices have not found widespread 
 Abstract Barium titanate (BaTiO 3 ) is a material of interest for photonic device applications due to its strong optical non‐linearity. However, BaTiO 3 ‐based devices have not found widespread adoption, in part due to the challenges associated with synthesizing high quality thin‐films. Here, high‐resolution scanning transmission electron microscope (STEM) imaging is used to investigate the atomic structure of both on‐ and off‐stoichiometric BaTiO 3 synthesized by molecular beam epitaxy (MBE). This investigation reveals an asymmetry in the way the BaTiO 3 atomic lattice accommodates off‐stoichiometry growth and unveils features beyond what is expected from diffraction or surface characterization techniques. Excess titanium incorporates into the BaTiO 3 lattice to form pervasive defects despite titanium‐rich films having a low surface roughness and high‐quality appearance in diffraction. Excess barium forms a rough, water‐soluble surface layer but does not significantly impact the quality of the BaTiO 3 lattice. STEM is used to map titanium atom displacement in real‐space. The average displacement distance is 30–60 pm in the strained thin‐films, higher than the &lt;20 pm displacement in bulk BaTiO 3 . Additionally, the titanium atom displacement direction deviates from the c ‐axis of the unit cell, which may have implications for the material's electro‐optic tensor and thus for electro‐optic device design.

Low-Temperature Dielectric Behavior Induced by Multiscale Cooperative Effects of CuCr<sub>2</sub>O<sub>4</sub> under Bias Electric Fields

2025-06-24
Guibo Yu , Guozhu Yuan , Ru Li +3 more | The Journal of Physical Chemistry C

A comparative consideration of the link between poling procedure, induced damage, and piezoelectric response in perovskite ferroelectrics

2025-06-23
Michael W. Mervosh , Haley N. Jones , Andrea P. ArgĂŒelles +2 more | Journal of Applied Physics
There has been much interest in recent years in improving Direct Current Poling (DCP) for piezoelectric materials. Some of the more promising substitutes include Alternating Current Poling (ACP), Water Quench 
 There has been much interest in recent years in improving Direct Current Poling (DCP) for piezoelectric materials. Some of the more promising substitutes include Alternating Current Poling (ACP), Water Quench Poling (WQP), and ACP with Field Cooling (ACP-FC). This paper summarizes the merits of these poling strategies and compares them to pulse poling. The results show that pulse poling outpaces both DCP and ACP in terms of the magnitude of piezoelectric response across a range of materials. Hard and soft piezoelectric samples in both single crystal and textured form were poled using all these techniques. For the single crystal samples (with compositions of Mn: Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) and Sm: PIN–PMN–PT), pulse poling generated the greatest increase in d33 and keff relative to DCP, with both piezoelectrics seeing increases above 65%. In the case of the {001} textured Mn: PMN–PZT–PT material, pulse poling and ACP-FC reduced the loss of the system and improved its mechanical quality factor (Qm) by 20% and 4%, respectively. These phenomena were further investigated via Rayleigh analysis to quantify each poling strategy’s impact on domain wall dynamics. The textured ceramic samples showed lower overall values of α (which is related to the mobility and concentration of domain walls) when compared to the single crystals. It was found that α decreased for the unconventionally poled textured samples relative to DCP, whereas the single crystals’ α values increased. Samples that underwent WQP experienced significant microcracking, limiting possible applications.

Interfacial Manipulation of Polar Topologies in Oxide Ferroelectric Films

2025-06-23
Yanpeng Feng , Yujia Wang , Yun‐Long Tang +2 more | Advanced Functional Materials
Abstract Topological polar structures hold significant potential for high‐density memories and low‐power electronic devices. Interfacial engineering offers a promising route to manipulate topological polar structures in ferroelectric heterostructures, yet the 
 Abstract Topological polar structures hold significant potential for high‐density memories and low‐power electronic devices. Interfacial engineering offers a promising route to manipulate topological polar structures in ferroelectric heterostructures, yet the underlying mechanisms remain elusive. Here, deterministic manipulation of topological polar Bloch points and merons in epitaxial PbTiO 3 (PTO) films are demonstrated via designing symmetric and asymmetric interfaces. By integrating SrRuO 3 (SRO) and SmScO 3 (SSO) layers, it is shown that symmetric PTO/SSO interfaces effectively stabilize polar Bloch points in PTO/SSO bilayers and (PTO) 13 /(SSO) 9 superlattices whereas asymmetric configurations (e.g., SRO/PTO, SRO/PTO/SSO) favor the formation of polar merons, which are visualized by aberration‐corrected scanning transmission electron microscopy. Phase‐field simulations reveal that the stabilization of Bloch points and merons is governed by the competition between elastic and electrostatic energies. The built‐in electric field and interfacial symmetry coupling with topological textures are identified as critical factors in modulating topological stability. Piezoresponse force microscopy measurements demonstrate that the presence of polar Bloch points enhances the piezoelectric response of the ferroelectric films. These findings illustrate interfacial engineering as a key strategy for designing and stabilizing nanoscale polar topologies, which may promote their potential applications in future electronic devices.

Improving the temperature stability of tunable devices by using composition-spread epitaxial ferroelectric <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi mathvariant="normal">B</mml:mi><mml:msub><mml:mi mathvariant="normal">a</mml:mi><mml:mi>x</mml:mi></mml:msub><mml:mi mathvariant="normal">S</mml:mi><mml:msub><mml:mi mathvariant="normal">r</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:mi>Ti</mml:mi><mml:msub><mml:


2025-06-23
Tingwu Liu , Xiangyu Zhang , Yanpeng Feng +7 more | Physical Review Materials

Nanocrystal BaTiO3: Pressure-induced transformation from mixed ionic–electronic to pure electronic cyclic conduction

2025-06-23
Min Wang , Rusen Yang , Hua Pang | The Journal of Chemical Physics
The electrical transport characteristics of nano-barium titanate (BaTiO3) were systematically investigated under high pressures up to 35.64 GPa using AC impedance spectroscopy measurements and first-principles calculations. Impedance spectroscopy measurements provide 
 The electrical transport characteristics of nano-barium titanate (BaTiO3) were systematically investigated under high pressures up to 35.64 GPa using AC impedance spectroscopy measurements and first-principles calculations. Impedance spectroscopy measurements provide insights into the conduction mechanism involving pressure-induced transformation from mixed ionic-electronic to pure electronic cyclic conduction. Through first-principles calculations, we have elucidated the underlying physical mechanisms responsible for the emergence of transformation from mixed ionic-electronic to pure electronic cyclic conduction. This phenomenon arises from variations in C-axis compressibility and phase transition from tetragonal to cubic phase, resulting in abrupt changes in electron density around oxygen atoms. These discontinuous changes are accompanied by alterations in initial resistance (R), relaxation frequency (F), and dielectric constant. By applying pressure, it becomes possible to effectively control the lattice spacing, thereby manipulating the charge density of OII ions and facilitating a seamless transition between mixed ionic-electronic and pure electronic conduction pathways. Pressure modulation also regulates the migration behavior of O2- ions, leading to an enhancement in the conductivity of nano-BaTiO3 materials. This study contributes to advancing our understanding of the transformation from mixed ionic-electronic to pure electronic cyclic conduction occurring within solid electrolytes.

Erratum: “Ferroelectric capacitor with an asymmetric double-layer PLZT structure for FRAM” [Appl. Phys. Lett. <b>120</b>, 102901 (2022)]

2025-06-23
Wensheng Wang , Ko Nakamura , Takashi Eshita +7 more | Applied Physics Letters

Charge compensation model for the lateral expansion of ferroelectric domains inverted by force-microscope tips

2025-06-23
E. V. Podivilov , B. Sturman | Journal of Applied Physics
The advent of scanning force microscopy (SFM) and the discovery of domain wall (DW) conduction have revolutionized the area of ferroelectric domain reversal and transferred it to the nano-scale with 
 The advent of scanning force microscopy (SFM) and the discovery of domain wall (DW) conduction have revolutionized the area of ferroelectric domain reversal and transferred it to the nano-scale with promises for nano-electronic and nano-scale reversible memory devices. Numerous experiments with application of voltage pulses to SFM tips show a fast local forward growth of inverted domains followed by their strong lateral expansion. Most of the explanations of the lateral expansion ignore the charge compensation of arising bound polarization charges; they are physically untenable. We propose a simple self-consistent quantitative model for the lateral expansion accounting for the necessary charge compensation via the DW conduction. This model involves injection of the compensating charge carriers from the tip. It possesses remarkable flexibility, is in good agreement with the experimental data for lithium niobate crystals, and predicts new features of the domain reversal.

Ferroelectric Domains and Evolution Dynamics in Twisted CuInP<sub>2</sub>S<sub>6</sub> Bilayers

2025-06-20
Dongyu Bai , Junxian Liu , Yihan Nie +4 more | Small Methods
Abstract Polar domains and their manipulation—particularly the creation and dynamic control—have garnered significant attention, owing to their rich physics and promising applications in digital memory devices. In this work, using 
 Abstract Polar domains and their manipulation—particularly the creation and dynamic control—have garnered significant attention, owing to their rich physics and promising applications in digital memory devices. In this work, using density functional theory (DFT) and deep learning molecular dynamics (DLMD) simulations, it is demonstrated that polar domains can be created and manipulated in twisted bilayers of ferroelectric CuInP 2 S 6 , as a result of interfacial ferroelectric (antiferroelectric) coupling in AA (AB) stacked region. Unlike the topological polar vortex and skyrmions observed in superlattices of (PbTiO 3 ) n /(SrTiO 3 ) n and sliding bilayers of BN and MoS 2 , the underlying mechanism of polar domain formation in this system arises from stacking‐dependent energy barriers for ferroelectric switching and variations in switching speeds under thermal perturbations. Notably, the thermal stability and polarization lifetimes are highly sensitive to twist angles and temperature, and can be further manipulated by external electric fields and strain. Through multi‐scale simulations, this study provides a novel approach to exploring how twist angles influence domain evolution and underscores the potential for controlling local polarization in ferroelectric materials via rotational manipulation.

Influence of BaTiO3 on the piezoelectric and ferroelectric properties of 0.36BiScO3-0.64PbTiO3 ceramics

2025-06-19
S. Sasikumar , J. Mangaiyarkkarasi , R. Jothi Ramalingam +2 more | Applied Physics A

Dielectric Properties and Defect Chemistry of Tb/Ho-Co-Doped BaTiO3 Ceramics

2025-06-19
Junwei Liu , Xin Wei , Qiaoli Liu +3 more | Materials
Co-doping at Ba and Ti sites with double rare-earth elements has proven an effective strategy for enhancing the dielectric properties of BaTiO3 ceramics. Among intermediate-sized rare-earth ions, Tb and Ho 
 Co-doping at Ba and Ti sites with double rare-earth elements has proven an effective strategy for enhancing the dielectric properties of BaTiO3 ceramics. Among intermediate-sized rare-earth ions, Tb and Ho exhibit amphoteric behavior, occupying both Ba and Ti sites. Investigating the site occupation, defect chemistry, and dielectric effects of Tb and Ho in BaTiO3 is therefore valuable. In this work, Tb/Ho-co-doped BaTiO3 ceramics with the composition (Ba1−xTbx)(Ti1−xHox)O3 (x = 0.01~0.10) were fabricated at 1400 °C via solid-state reaction, and their solid solubility and crystal structures are confirmed. Microstructure, dielectric properties, photoluminescence, and valence states of samples with a single phase were systematically studied. Both the lattice parameter a and unit cell volume increase with doping level. The ceramic with x = 0.02 meets the X5S dielectric specification. Ho and Tb ions both demonstrate amphoteric site occupancy: Ho exists solely as Ho3+ at both Ba and Ti sites, while Tb exhibits mixed valence states as Ba-site Tb3+ and Ti-site Tb4+. As the doping content increases, the concentration of Tb4+ at Ti sites decreases, and the quantity of Ba-site Ho3+ ions initially increases to a maximum before decreasing. Defect compensation mechanisms within the samples are also discussed.

Water oxidation mechanisms on ferroelectric PbTiO <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi/><mml:mn>3</mml:mn></mml:msub></mml:math> (001) surface: A density functional theory study

2025-06-18
NULL AUTHOR_ID | Physical review. B./Physical review. B

Investigations on Structural and Ferroelectric Characteristics of Ba(1-x) Ca(x)TiO3 Ceramics (x=0.1-0.5) for High Frequency Applications

2025-06-17
P Sakuntala , Vinodini S.E.Naina , Pradyutha A.Ch. +3 more | ECS Journal of Solid State Science and Technology
Abstract This paper explores the composition-dependent structural and ferroelectric properties of Ba(1-x)Ca(x)TiO₃ (BCT) ceramics for x = 0.1 to 0.5, synthesized using the solid-state reaction method and sintered at 1000°C. 
 Abstract This paper explores the composition-dependent structural and ferroelectric properties of Ba(1-x)Ca(x)TiO₃ (BCT) ceramics for x = 0.1 to 0.5, synthesized using the solid-state reaction method and sintered at 1000°C. The novelty lies in systematically correlating vibrational modes, phase evolution, and ferroelectric properties over a wide frequency range (50 Hz-1 KHz) at relatively low sintering temperature across a broad compositional range. X-ray diffraction confirmed a phase transition from tetragonal to a mixed phase. Fourier transform infrared and Raman spectroscopy revealed vibrational mode changes due to Ca doping. Polarization-electric field (P-E) loop analysis showed optimal ferroelectric behavior at x = 0.3 and 0.4. Additional scanning electron microscopy and energy-dispersive spectroscopy data provide insights into microstructural and chemical properties. SEM-EDS analysis revealed the uniform microstructure and stoichiometric elemental distribution. These BCT ceramics are promising candidates for high-frequency electronic applications.

Mechanism for enhanced piezoelectric response in excess alkali metal doped KNN-based ceramics

2025-06-17
Yilong Liu , Junyan Wu , Ting Wang +2 more | Journal of Alloys and Compounds

Highly Efficient Cooling via Synergistic Electro‐Thermal Phase Changes

2025-06-17
Guangfa Wang , Peijia Bai , Shaoheng Yuan +4 more | Advanced Materials
Abstract Electro‐phase change materials (electro‐PCM), based on the electrocaloric effect, have attracted significant attention and achieved rapid development in the field of cooling technology owing to their environmental protection, low 
 Abstract Electro‐phase change materials (electro‐PCM), based on the electrocaloric effect, have attracted significant attention and achieved rapid development in the field of cooling technology owing to their environmental protection, low energy consumption, and miniaturization. However, due to their limited isothermal entropy change and thermal conductivity, the cooling capacity of the electro‐PCM devices has severely limited their cooling effect on electronic devices. Here, with the synergistic electro‐thermal phase changes, the entropy change and thermal conductivity of electro‐PCM are significantly improved by stacking it with thermo‐phase change materials (thermo‐PCM). Compared with that of the electro‐PCM, the entropy change and thermal conductivity of electro‐thermal phase change materials (ETPCM) stack can be up to 4.68‐fold (from 28.31 to 132.35 J kg −1 K −1 at electric field of 100 MV m −1 ) and 2.39‐fold (from 0.18 to 0.43 W m −1 ·K −1 ), respectively. The practicality of this strategy has also been fully validated by cooling a simulated electronic chip (1.75 W cm −2 ) with a temperature drop of 49.32 K after constructing ETPCM stack‐based cooling device using the electrostatic actuation prototype. The synergistic enhancement of entropy change and thermal conductivity paves the way for the future direction of electrocaloric cooling toward interdisciplinary fusion.

Synergistic effects of grain orientation and microstructure modification in PMN‐PT electrocaloric ceramics

2025-06-16
Li‐Qian Cheng , Zhiping Wang , Zhenhua Ma +4 more | International Journal of Applied Ceramic Technology
Abstract Grain orientation engineering is an effective approach to tailor the electrical properties in ferroelectric ceramics. Although it was found that the electrocaloric (EC) performance can be affected due to 
 Abstract Grain orientation engineering is an effective approach to tailor the electrical properties in ferroelectric ceramics. Although it was found that the electrocaloric (EC) performance can be affected due to grain orientation design in literatures, the grain microstructure modification in textured EC ceramics was rarely emphasized. Here, 0.90 Pb(Mg 1/3 Nb 2/3 )O 3 ‒0.10PbTiO 3 (PMN‐10PT) ceramics with &lt;111&gt; orientation were fabricated. A combination approach of texturing and grain structure modification was designed. An optimization of two‐step sintering process was utilized to obtain the &lt;111&gt;‐textured ceramics with dense body and relatively uniform grain structures. Compared to normal (single‐step) sintered ceramics, the dielectric breakdown strength of the &lt;111&gt;‐textured PMN‐10PT ones sintered by two steps enhanced from 53 to 69 kV cm −1 . Especially, the &lt;111&gt;‐textured ceramics synthesized via 1230°C/1200°C sintering process exhibited an enhanced adiabatic temperature Δ T change of 0.88 K when the applied field was 35 kV cm −1 , which improved EC performance by 39.7% compared to randomly oriented ceramics, and was also 11.4% higher than that of the conventionally sintered textured samples. This work analyzed the synergistic effect of texture and grain microstructure on the EC performance of PMN‐PT ceramics, and provides a facile sintering method to further enhance the EC property of ferroelectric ceramics.

Enhanced electrostatic energy-storage performances in the high-entropy Bi0.5Na0.5TiO3-based ceramic capacitors

2025-06-16
Wenjie Xie , Wenjing Yu , Yang Yang +5 more | Applied Physics Letters
As one of the core components in electronic devices, dielectric capacitors with superior electrostatic energy-storage performances have captured great interest recently. In this Letter, the B-site high-entropy end-member Ba(Ti0.2Zr0.2Hf0.2Fe0.2Nb0.2)O3 was 
 As one of the core components in electronic devices, dielectric capacitors with superior electrostatic energy-storage performances have captured great interest recently. In this Letter, the B-site high-entropy end-member Ba(Ti0.2Zr0.2Hf0.2Fe0.2Nb0.2)O3 was introduced into Bi0.5Na0.5TiO3 (BNT) ceramics to improve the entropy configuration. Accordingly, the coexisting PNRs with R3c and P4bm, enhanced dielectric relaxation, and decreased grain size were obtained in entropy modified BNT ceramics, leading to slim ferroelectric hysteresis (P–E) loops with reduced Pr and small hysteresis, as well as promoted electric breakdown strength (Eb). Resultantly, the optimal ceramics presented a high recoverable energy density (Wrec) of 7.1 J/cm3 and a high efficiency (η) of 89.5% under 360 kV/cm, along with excellent frequency (10–100 Hz), cycling (1–106), and temperature (25–160 °C) stability. This work demonstrates the practicability of high-entropy engineering in seeking for high-performance dielectric capacitors for advanced high/pulsed power devices.

Enhanced Electrocaloric Effect in Relaxor Ferroelectric Terpolymers by Morphotropic Phase Boundary

2025-06-16
Linxiao Xu , Yutie Gong , Shaochun Tang +3 more | Small
Relaxor ferroelectric terpolymers with a disordered helical relaxor conformation are promising candidates for developing electrocaloric cooling applications. However, most current studies focus on the electrocaloric effect in terpolymers with high 
 Relaxor ferroelectric terpolymers with a disordered helical relaxor conformation are promising candidates for developing electrocaloric cooling applications. However, most current studies focus on the electrocaloric effect in terpolymers with high chiral commoners, which remains relatively small in the low-electric-field regime. In this work, other than using typical helical relaxor compositions, it is reported that poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) terpolymer with its composition close to the morphotropic phase boundary may enable markedly enhanced electrocaloric effect, especially in the low-electric-field regime. The adiabatic temperature change of 3.2 K is achieved by a low electric field of 50 MV m-1 at room temperature, corresponding to ≈90% enhancement over pure relaxor counterparts. The improved electrocaloric response is attributed to the electric-field-induced disorder-to-order phase transition. These findings offer an alternative, promising route for the practical use of electrocaloric polymers for refrigeration devices.

Phase Transitions in Bi/Ca Modified AgNbO<sub>3</sub> Ceramics with Excellent Energy Storage Density and Storage Intensity

2025-06-16
Zhongna Yan , Jia He , Haiyan Chen +6 more | Small
Lead-free antiferroelectric (AFE) ceramics based on AgNbO3 represent attractive materials for energy storage applications but are limited by their recoverable energy density (Wrec). Here Bi3+/Ca2+ A-site modification of AgNbO3 ceramics 
 Lead-free antiferroelectric (AFE) ceramics based on AgNbO3 represent attractive materials for energy storage applications but are limited by their recoverable energy density (Wrec). Here Bi3+/Ca2+ A-site modification of AgNbO3 ceramics has yielded a particularly high Wrec of 4.4 J cm-3 and a superhigh recoverable energy storage intensity (ρ) of 21.46 × 10-3 J kV-1 cm-2 at 205 kV cm-1, the latter being the highest known value obtained at such a relatively low field for a lead-free ceramic. The modification shifts the dipole freezing temperature, Tf, to below room temperature, enhancing the room temperature stability of the AFE structure. The high Wrec is attributed to the enhancement of the maximum field-induced dielectric displacement and improved forward (EF) and backward (EB) fields. The work has also allowed for an examination of the poorly understood ±EU current peaks evident in current-electric field loops of AgNbO3-based ceramics, which is proposed to be related to a field-induced AFE to ferroelectric (FE) phase transition in the M1 or M2a phases and is absent in the M2b phase due to increased stability of the AFE phase. The exceptional performance of Bi3+/Ca2+ modified AgNbO3 ceramics is promising for potential use in ceramic capacitors for high pulsed power applications.

Investigating the temperature-dependent electro-optic behaviors in La-doped PMN-PT transparent ceramics

2025-06-16
Guoqing Shi , Yaqi Wang , M. H. Sang +7 more | Applied Physics Letters
Understanding the temperature-dependent electro-optic behaviors in (1 − x)[Pb(Mg1/3Nb2/3)O3]-x[PbTiO3] [(1 − x)PMN-xPT] is central to its device applications. In this work, 0.5 mol. % La-(1 − x)PMN-xPT transparent ceramics with 
 Understanding the temperature-dependent electro-optic behaviors in (1 − x)[Pb(Mg1/3Nb2/3)O3]-x[PbTiO3] [(1 − x)PMN-xPT] is central to its device applications. In this work, 0.5 mol. % La-(1 − x)PMN-xPT transparent ceramics with different solid solution ratios (i.e., x = 0.10, 0.15, 0.20, 0.25) were fabricated to study the temperature-dependent electro-optic behaviors. Two distinct temperature dependencies are revealed: for 0.85PMN-0.15PT and 0.90PMN-0.10PT, the measured electro-optic coefficient decreases with increasing temperature, while for 0.75PMN-0.25PT and 0.80PMN-0.20PT, the electro-optic coefficient first increases and then decreases rapidly with the increase in temperature. Based on the temperature-dependent dielectric, ferroelectricity, x-ray diffraction, and piezoresponse domain image analysis, the ferroelectric–ferroelectric phase transition is suggested to play a dominant role, with the ferroelectric state to relaxor state transition providing an auxiliary enhancement. This study provides valuable insights into understanding temperature-dependent electro-optic behaviors and should be instructive for the design and optimization of advanced electro-optic devices.

Improving Energy Storage Properties of Barium Zirconate Titanate Ceramics via Defect Dipole Engineering

2025-06-15
Zhiyi Wang , Zian Qin , Si Gao +4 more | Materials
Lead-free ceramic materials have been widely studied since dielectric capacitors became a key component for energy storage. In this work, we adopted defect dipole engineering and improved the energy storage 
 Lead-free ceramic materials have been widely studied since dielectric capacitors became a key component for energy storage. In this work, we adopted defect dipole engineering and improved the energy storage performance of barium zirconate titanate (BZT) ceramics by doping them with MnO2. With the increase in Mn content, the hysteresis loop changed from a conventional loop to a pinned hysteresis loop, resulting in a decrease in remnant polarization (Pr). When x = 0.02, the recoverable energy storage density (Wrec) reached 0.1561 J/cm2 @ 40 kV/cm, a 59% increase from undoped BZT. Further, XPS and EPR analyses confirmed that many oxygen vacancies were generated. We also performed SEM and TEM characterization and observed the microstructures. These results are consistent with theories suggesting that the formation of the pinned hysteresis loop is attributable to oxygen vacancies and defect dipoles.

Achievement of high energy density and efficiency in Bi(Mg<sub>0.5</sub>Hf<sub>0.5</sub>)O<sub>3</sub> modified Ba<sub>0.55</sub>Sr<sub>0.45</sub>TiO<sub>3</sub> ceramics

2025-06-15
Ihsan Ullah , Abdul Manan , Rajwali Khan +5 more | International Journal of Applied Ceramic Technology
Abstract (1 ‒ x )Ba 0.55 Sr 0.45 TiO 3 ‒ x Bi(Mg 0.5 Hf 0.5 )O 3 [(1 ‒ x )BST‒ x BMH] ( x = 0, 0.05, 0.10, 
 Abstract (1 ‒ x )Ba 0.55 Sr 0.45 TiO 3 ‒ x Bi(Mg 0.5 Hf 0.5 )O 3 [(1 ‒ x )BST‒ x BMH] ( x = 0, 0.05, 0.10, 0.15, and 0.20) ceramics were fabricated through the well‐known low‐cost solid‐state mix oxide sintering method. The physical and electrical properties were investigated for all ceramics sintered at 1350°C/2 h. X‐ray diffraction data analysis revealed single Perovskite phase with pseudocubic symmetry for all compositions. The microstructure examination revealed densely packed grains with lowest average grain size of 0.70 ”m for x = 0.15. BMH doping lowered the electrical conductivity that has significant effect on the breakdown voltage with increased activation energy. High recoverable energy storage density ∌4.69 J/cm 3 and high efficiency ∌91% at an electric field ∌450 kV/cm is achieved for 0.85BST−0.15BMH ceramic. Furthermore, 0.85BST−0.15BMH ceramic possess fast discharge time of ∌40 ns and a high power density of 122 MW/cm 3 at 180 kV/cm. These properties reveal that 0.85BST−0.15BMH ceramic is a potential candidate for power electronic capacitor applications working in high‐temperature condition.

Real-space observation of polarization induced charges at nanoscale ferroelectric interfaces

2025-06-13
Masaya Takamoto , S. Tƍyama , Takehito Seki +4 more | Science Advances
Unique electrical properties emerging at nanoscale ferroelectric interfaces originate from the polarization induced charges. However, real-space characterization of polarization induced charges at nanoscale ferroelectric interfaces has been extremely challenging. Here, 
 Unique electrical properties emerging at nanoscale ferroelectric interfaces originate from the polarization induced charges. However, real-space characterization of polarization induced charges at nanoscale ferroelectric interfaces has been extremely challenging. Here, directly observing the nanoscale electric field by tilt-scan averaged differential phase contrast scanning transmission electron microscopy enables us to measure the spatially varying total charge density profiles across both head-to-head and tail-to-tail domain walls in a ferroelectric crystal. Combined with atomic column displacement measurements, the spatial distribution of polarization bound charges and screening charges across the domain walls can be disentangled. Our results reveal the true charge states of the nanoscale ferroelectric interfaces, providing an opportunity for experimentally exploring the interplay between atomic-scale local polarization structures and their charge states in ferroelectric interfaces.

Achieving a High Energy Storage Performance in Grain Engineered (Ba,Sr)(Zr,Ti)O3 Ferroelectric Films Integrated on Si

2025-06-13
Fuyu Lv , Chao Liu , Hongbo Cheng +1 more | Nanomaterials
BaTiO3-based lead-free ferroelectric films with a large recoverable energy density (Wrec) and a high energy efficiency (η) are crucial components for next-generation dielectric capacitors, which are used in energy conditioning 
 BaTiO3-based lead-free ferroelectric films with a large recoverable energy density (Wrec) and a high energy efficiency (η) are crucial components for next-generation dielectric capacitors, which are used in energy conditioning and storage applications in integrated circuits. In this study, grain-engineered (Ba0.95,Sr0.05)(Zr0.2,Ti0.8)O3 (BSZT) ferroelectric thick films (~500 nm) were prepared on Si substrates. These films were deposited at 350 °C, 100 °C lower than the temperature at which the LaNiO3 buffer layer was deposited on Pt/Ti. This method reduced the (001) grain population due to a weakened interface growth mode, while promoting volume growth modes that produced (110) and (111) grains with a high polarizability. As a result, these films exhibited a maximum polarization of ~88.0 ÎŒC/cm2, a large Wrec of ~203.7 J/cm3, and a high energy efficiency η of 81.2% (@ 6.4 MV/cm). The small-field dielectric constant nearly tripled as compared with that of the same BSZT/LaNiO3 heterostructure deposited at the same temperature (350 °C or 450 °C). The enhanced linear dielectric response, delayed ferroelectric polarization saturation, and increased dielectric strength due to the nano-grain size, collectively contributed to the improved energy storage performance. This work provides a novel approach for fabricating high-performance dielectric capacitors for energy storage applications.

Correlation of Structural Properties and Ferroelectricity in Cobalt and Iron Co‐Doped Aurivillius Ceramics Based on Rietveld Refinement Analysis

2025-06-13
Mahmoud S. Alkathy , Vitor F. Barbosa , Ricardo Pereira Bonini +3 more | Crystal Research and Technology
Abstract This research examines the structural and ferroelectric characteristics of lanthanum‐modified Bismuth Titanate (Bi 4 Ti 3 O 12 ) ceramics by co‐doping with cobalt (Co 3+ ) and iron 
 Abstract This research examines the structural and ferroelectric characteristics of lanthanum‐modified Bismuth Titanate (Bi 4 Ti 3 O 12 ) ceramics by co‐doping with cobalt (Co 3+ ) and iron (Fe 3+ ). Structural refinement demonstrates that the La 3+ substitution at Bi 3+ significantly decreases titanium–oxygen bond lengths, augmenting the covalent character crucial for altering the ferroelectric response. Incorporating Co 3 âș and Fe 3 âș induces defects, causing a reduction in maximum polarization from around 10 ”C cm − 2 to about 4.88 ”C cm − 2 . Structural examinations indicate an orthorhombicity of around 7.64×10 −3 in the BLaT sample and 7.49×10 −3 in the BLaT‐FC2 sample, corresponding with their respective polarization tendencies. A defect pinning hindered the motion of the domain wall in BLaT‐FC2, resulting in a constricted (P–E) hysteresis loop. Nevertheless, repeated electrical cycling enhances ferroelectric responses, allowing greater polarization alignment through progressive defect mitigation. As a result, structural defects and functional properties are dynamically interacting. The results highlight the significant impact of defect dynamics and structural changes on controlling the ferroelectric performance of Bi‐based layered structure ceramics. This indicates that deliberate doping strategies and defect engineering can substantially enhance the reliability and effectiveness of ferroelectric materials for advanced electronic applications.

Synthesis, Optical Characterization, and Electrical Properties of SrBi2Nb2O9 Doped with Praseodymium

2025-06-13
Mohamed Afqir , Yingzhi Meng , Didier Fasquelle +4 more | Journal of Electronic Materials

Nitride ferroelectric films deposited in capacitor structures for high-temperature memory

2025-06-11
Adam Liebendorfer | Scilight
Approach highlights methods for using lower-cost molybdenum electrodes and the impact of oxygen on impeding electrical pathways. Approach highlights methods for using lower-cost molybdenum electrodes and the impact of oxygen on impeding electrical pathways.

Semiconductive flexoelectric piezoelectric metamaterials with strong electromechanical response

2025-06-10
Dongxia Tian , Baoju Xia , Yagang Qi +4 more | Science China Materials

The DOS Function under Intense Electric Field in HD Kane-type Materials and the Relaxation Time Due to AMS

2025-06-08
| Series on the foundations of natural science and technology

High‐Quality Epitaxial Five‐Layer Aurivillius Films with In‐Plane Ferroelectricity for Electrocaloric Cooling

2025-06-06
Sara Lafuerza , J. Blasco , Marco Evangelisti +7 more | Advanced Electronic Materials
Abstract High‐quality purely c ‐axis oriented epitaxial thin films of the Aurivillius phase Sr 2 Bi 4 Ti 5 O 18 with n = 5 (Sr,Bi)TiO 3 perovskite‐like layers, are 
 Abstract High‐quality purely c ‐axis oriented epitaxial thin films of the Aurivillius phase Sr 2 Bi 4 Ti 5 O 18 with n = 5 (Sr,Bi)TiO 3 perovskite‐like layers, are grown on SrTiO 3 substrates by pulsed laser deposition. The highest crystalline quality is obtained with a 20 wt.% Bi‐excess target and average stacking order values in the proximity of the ideal value n = 5 are attained for an optimum deposition temperature of 650 °C. Scanning transmission electron microscopy reveals regions with n ranging from 4 to 6 around an average thickness of n = 5, in agreement with the X‐ray diffraction analysis. Interdigital electrodes are used to probe the in‐plane polarization and survey the electrocaloric properties. A maximum adiabatic temperature change of Δ T ∌ 0.95 °C for an electric field of 150 kV cm −1 is observed at ≈135 °C. Larger values are expected at higher temperatures around the ferroelectric Curie temperature, T C . Since T C of Sr 2 Bi 4 Ti 5 O 18 can be tuned by codoping, the findings pave the way toward a large electrocaloric effect at ambient temperature.