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In many studies, the properties of BiFeO3–BaTiO3 (BF–BT) ceramics vary greatly using different raw reagents, which makes it challenging to obtain reliable and repeatable properties of BF–BT‐based devices. In this work, 0.7BiFeO3–0.3BaTiO3 (0.7BF–0.3BT) ceramics were fabricated by a conventional solid‐phase synthesis using TiO2 reagents with varied purities of 98%, 99%, 99.9%, and 99.99%, respectively. The phase structure, microstructure, ferroelectric, and piezoelectric properties were comprehensively studied. All compositions of the ceramics exhibit a pseudo‐cubic phase perovskite structure, and the fraction of the rhombohedral phase increases with increasing the TiO2 purity. Additionally, backscattered electron images and energy‐dispersive spectroscopy revealed an obvious core–shell structure within grains. In particular, the 0.7BF–0.3BT ceramics prepared with 98% purity TiO2 exhibited superior ferroelectric and piezoelectric properties, d33 ∼ 220 pC/N and d33∗$d_{{\mathrm{33}}}^{\;*}$ ∼ 230 pm/V. The ceramics prepared with higher purity TiO2 suffered from severe leakage conduction, which can be well addressed by adding excess TiO2. Our work reveals the importance of different grades of purity TiO2 on the electrical properties of BF–BT ceramics. [ABSTRACT FROM AUTHOR]

Electronic components are widely used in the field of electronic information. It is more and more important to prepare miniaturized and better performance electronic components. In this work, Sr1−3x/2YxTiO3 (x = 0.005, 0.0075, 0.01, 0.0125) ceramics were prepared by the traditional solid‐phase synthesis method. N2 annealing induces the appearance of lattice defects and free carriers (VO..,e′,Ti3+)$(V_{\mathrm{O}}^{..},\,{\mathrm{e^{\prime}}},\,{\mathrm{T}}{{\mathrm{i}}^{3 + }})$ and defect dipoles (YṠr−VSr′′,Ti3+−Vo..−Ti3+${{\mathrm{Y}}_{{\mathrm{\dot Sr}}}} - {V^{\prime\prime}_{{\mathrm{Sr}}}},{\mathrm{T}}{{\mathrm{i}}^{3 + }} - V_{\mathrm{o}}^{..} - {\mathrm{T}}{{\mathrm{i}}^{3 + }}$). The defect dipoles easily induce the electron‐pinning defect dipole effect and inhibit the movement of free carriers, which can enhance the dielectric constant and reduce the dielectric loss simultaneously. The electrons cannot pass through the insulating grain boundary and accumulate in the conductive grains under an external electric field, forming the internal barrier layer capacitance (IBLC). The ceramic was further refined by high‐energy ball milling to improve the temperature and frequency stability of the ceramic. Under the combined action of rare‐earth doping, atmosphere annealing, and high‐energy ball milling, a dielectric ceramic material with colossal permittivity, low loss, high resistivity, frequency, and temperature stability that meets the ELA X9R capacitor standard was prepared. [ABSTRACT FROM AUTHOR]

The 0.55Bi(Mg1/2Ti1/2)O3–0.45PbTiO3 ceramics exhibit notable dielectric anomalies across three temperature ranges. The low‐temperature anomaly is attributed to a reentrant dipole glass‐like relaxor behavior; the mid‐temperature anomaly results from a ferro‐paraelectric phase transition; and the high‐temperature anomaly is associated with a diffuse phase transition. The system demonstrates favorable piezoelectric, electromechanical, and ferroelectric properties. Specifically, the ceramic presents a piezoelectric coefficient (d33) of 220 pC/N, an electromechanical coupling factor (kp) of 27%, and a remanant polarization (Pr) of 32.5 μC/cm2. Moreover, it maintains an operational capability up to 643 K. The unsaturated P(E) loops are formed through the coupling polarization between polar nanoregions (PNRs) and P4mm ferroelectric domains. By examining the electrical modulus, the dynamic PNRs resulting from ferroelectric phonon localization and the formation of P4mm ferroelectric domains were analyzed. The result reveals a mesoscale coupling relationship between the origin of high‐temperature piezoelectric stability and the dynamics of PNRs, thereby providing noble insights into the (1 − x)BiMeO3–xPbTiO3 system. [ABSTRACT FROM AUTHOR]

High‐temperature piezoelectric sensing is usually used in the aerospace, automotive, and power plant fields. High temperature piezoelectric ceramics are considered the key materials in these fields. In this paper, Ca1−x(Ba1/2Sr1/2)xBi2Nb1.985(W3/4Mn1/4)0.015O9 (x = 0.05, 0.10, 0.15 and 0.20) (C1−xBSxBNWM) has been synthesized by a traditional solid state reaction method. The effects of substitution of calcium at the A‐site by barium and strontium on phase evolution and piezoelectric properties of the CaBi2Nb2O9 orthorhombic Aurivillius phases were investigated. The crystal structure of piezoelectric ceramics was characterized by XRD, Rietveld refinement, and Raman spectroscopy. Co‐substitution of barium/strontium (Ba2+/Sr2+) and tungsten/manganese (W6+/Mn4+) resulted in lattice distortion of C1−xBSxBNWM ceramics. The results induce that the tetragonal crystal structure increase with increasing the co‐substitution cations. Isothermal impedance spectroscopy confirmed intrinsic thermally activated conduction in the system. The C1−xBSxBNWM ceramics with x = 0.15 exhibit a very high Curie temperature (TC ∼ 923°C), a reasonable piezoelectric coefficient (d33 = 13.3 pC/N). Remarkably, even after thermal annealing at temperatures up to 800°C, it still retains a high d33 of 13 pC/N. In addition, the C0.85BS0.15BNWM ceramic had a relatively high resistivity (3.82 × 106 Ω·cm, 500°C). The Ca0.85(Ba1/2Sr1/2)0.15Bi2Nb1.985(W3/4Mn1/4)0.015O9 ceramics make possible their application in high‐temperature acceleration transducers. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the effect of processing parameters and composite regulation on the structure and property relationship of lightweight low‐permittivity Li2O–Al2O3–B2O3 dielectric system. Li2BAlO4 ceramic and (1 − x)Li2BAlO4–xSrTiO3 ceramics were synthesized using a conventional solid‐state reaction method. Thermodynamic analysis, sintering temperature, phase formation, crystal structure, and microwave dielectric properties were investigated. Thermal analysis revealed a melting temperature of 847°C, suggesting a comparatively low temperature for the sintering of Li2BAlO4 ceramics. Li2BAlO4 crystalized into a monoclinic structure with P21/c space group, with [Al2B2O8] rings connected by [BO3] triangles and [AlO4] tetrahedra through Al–O–Al bridges. Dense Li2BAlO4 ceramics with a relative density of ∼97.7% were sintered at 750°C and had optimal microwave dielectric properties with relative permittivity (εr) of 5.13, quality factor (Q × f) of 22 610 GHz, and the temperature coefficient of resonance frequency (τf) of −112.5 ppm/°C. The 0.88Li2BAlO4–0.12SrTiO3 composite ceramic has excellent microwave dielectric properties with εr = 8.83, Q × f = 14 000 GHz, τf = 4.6 ppm/°C. The ceramics also demonstrated an inert behavior with silver electrodes proving its application in low‐temperature cofired ceramic (LTCC) technology. [ABSTRACT FROM AUTHOR]

High‐entropy strategy is a design that uses multiple elements to increase configurational entropy. As an emerging research field, high‐entropy was originally applied to metals, but it has shown great potential in inorganic nonmetallic materials. Since the first discovery of colossal dielectric permittivity in high‐entropy ceramics, it indicates that the high‐entropy strategy is feasible in dielectric ceramics. The multi‐ion solid solution will bring a broader space for the material structure and property tailoring. With the research of domestic and foreign scholars in high‐entropy dielectrics, we believe that entropic engineering can effectively regulate dielectric properties. The review paper explores the potential of the high‐entropy strategy in dielectric ceramics. It provides a detailed overview of the structural properties and the potential benefits of utilizing high‐entropy materials in dielectric ceramics. The review also covers the current research advancements in the field and provides insights into future directions for further development of high‐performance dielectric ceramics. [ABSTRACT FROM AUTHOR]

Dielectric ceramics with both excellent energy storage and optical transmittance have attracted much attention in recent years. However, the transparent Pb‐free energy‐storage ceramics were rare reported. In this work, we prepared transparent relaxor ferroelectric ceramics (1 − x)Bi0.5Na0.5TiO3–xNaNbO3 (BNT–xNN) by conventional solid‐state reaction method. We find the NN‐doping can enhance the polarization and breakdown strength of BNT by suppressing the grain growth and restrained the reduction of Ti4+ to Ti3+. As a result, a high recoverable energy‐storage density of 5.14 J/cm3 and its energy efficiency of 79.65% are achieved in BNT–0.5NN ceramic at 286 kV/cm. Furthermore, NN‐doping can promote the densification to improve the optical transmittance of BNT, rising from ∼26% (x = 0.2) to ∼32% (x = 0.5) in the visible light region. These characteristics demonstrate the potential application of BNT–xNN as transparent energy‐storage dielectric ceramics. [ABSTRACT FROM AUTHOR]

In this work, cyclotetravanadate Na2SrV4O12 was synthesized at a relatively low sintering temperature of ∼500°C using a solid‐state reaction method. X‐ray diffraction and a transmission electron microscope characterization featured a tetragonal structure that was built by a 3D frame of isolated tetracyclic (V4O12)4−. Dielectric measurements demonstrated strong dependence on frequency and temperature. A low relative permittivity of εr ∼ 8 ± 0.2 and a dielectric (loss tanδ) ∼ 0.4 ± 0.01 was achieved at a frequency of 10 kHz and room temperature. ac impedance and conductivity analysis revealed a thermally activated migration behavior of charge carriers with a short‐range hopping feature. XPS analysis validated the existence of oxygen vacancy and reduction in vanadium (from V5+ to V4+), which gave rise to charged lattice defects. The migration or hopping of such charged defects was responsible for the observed electrical behaviors. Owing to the simple composition, inexpensive raw materials and low density (2.99 g/cm3) make Na2SrV4O12 ceramic a potential candidate for lightweight devices and in photocatalytic degradation and all‐solid‐state ion batteries. [ABSTRACT FROM AUTHOR]

High‐performance colossal‐permittivity (CP) materials have huge potential applications in the miniaturization of electronic components and high‐energy storage applications. Here, we report CP behavior in rare‐earth Ln‐doped BaTiO3 (Ln = La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, and Er) ceramics. CP (>1 × 105) and low loss (<5% at 1 kHz) were achieved. Additionally, all ceramic samples with excellent temperature stability over a wide temperature range (25–250°C). X‐ray photoelectron spectroscopy verified the existence of point defects (Ti3+ and VO••$V_{\rm{O}}^{{\rm{ \bullet \bullet }}}$) in Ln‐doped BaTiO3 ceramic samples annealed in an N2 atmosphere. Electron paramagnetic resonance further demonstrated the existence of Ti3+. The coupling of point defects forms an electron‐pinned defect‐dipoles (EPDD) effect and induces strong hopping polarization. In addition, an internal barrier layer capacitance (IBLC) effect and a surface barrier layer capacitor (SBLC) effect are identified by impedance spectroscopy and DC bias voltage. The CP is attributed to the combined effect of EPDD, IBLC, and SBLC. Furthermore, the high‐temperature stability of CP is related to the strong coupling of defect‐dipole complexes. [ABSTRACT FROM AUTHOR]

The 0.65Bi(Mg1/2Ti1/2)O3‐0.35PbTiO3 (0.65BMT‐0.35PT) ceramic, nearby morphotropic phase boundary (MPB), between tetragonal and rhombohedral was prepared. Dielectric permittivity dependence of temperature exhibits a re‐entrance dipole glass‐like behavior near room temperature. The behavior was described by the Vogel‐Fulcher law and the new glass model. Furthermore, a phenomenological statistical model was employed to determine the distribution of clusters dependence of temperature. The lattice dynamics of the 0.65BMT‐0.35PT ceramic was estimated by Raman spectroscopy from 298‐723 K. A disruption of ferroelectric long‐range order and an occurrence of local lattice distortion were revealed. The relaxor‐ferroelectric (r‐FE) nature of the 0.65BMT‐0.35PT was characterized by polarization‐electric field P(E). A close relation between the distribution of clusters and ferroelectric properties was established. [ABSTRACT FROM AUTHOR]

Environmentally benign lead‐free bulk ceramics with high recoverable energy density (Wrec) are very attractive in advanced pulsed power capacitors. In this work, composition engineering was adopted by La3+ modification to improve the energy storage performance of Ag1−3xLaxNbO3 ceramics. It was found that the antiferroelectric (AFE) phase was stabilized after La3+ substitution, as a result of the reduced tolerance factor t. Significant improvement of Wrec and energy storage efficiency (η) were achieved with value of 3.12 J/cm3 and 0.63 for x = 0.02 at an electric field of 230 kV/cm, more than 1.5 times the value of pure AgNbO3 (Wrec = 1.9 J/cm3, η = 0.40). The excellent energy storage properties are resulted from the increased antiferroelectric‐ferroelectric phase transition electric field (EF), ferroelectric‐antiferroelectric phase transition electric field (EA), and breakdown electric field (Eb). The enhanced Eb was ascribed to the decreased grain size and increased electrical resistivity upon La3+ modification. The feature makes Ag1−3xLaxNbO3 a potential candidate for energy storage applications. [ABSTRACT FROM AUTHOR]

It has been a challenge to provide a unified description of the dielectric response vs temperature for ferroelectrics with diffuse phase transition (DPT) and relaxor behaviors, which can be used to fit the dielectric response both below and above the peak temperature (Tm). Most of the available functions used in fitting experimental data only provide a description of the dielectric permittivity near and above Tm. In this work, employing a macroscopic and phenomenological statistical model and using Ba(Ti1−x Zrx)O3 ceramics as an example, we revisit the dielectric permittivity's temperature dependence, analyzing their DPT and relaxor behaviors and providing a complete description over the whole temperature range. We show that good agreements between theoretical and experimental results can be achieved. To better understand how Ba(Ti1−x Zrx)O3 ceramics changes from DPT to relaxor with increasing x, we also discuss the relation between the fitting parameters and Ba(Ti1−x Zrx)O3's composition and structure, which suggests that the parameters from the statistical model reflect the size of the correlated Ti ions (small clusters or polar nanoregions), which largely determine the behavior of Ba(Ti1−x Zrx)O3 ceramics. [ABSTRACT FROM AUTHOR]

It has been a challenge to provide a unified description of the dielectric response vs temperature for ferroelectrics with diffuse phase transition (DPT) and relaxor behaviors, which can be used to fit the dielectric response both below and above the peak temperature (Tm). Most of the available functions used in fitting experimental data only provide a description of the dielectric permittivity near and above Tm. In this work, employing a macroscopic and phenomenological statistical model and using Ba(Ti1−x Zrx)O3 ceramics as an example, we revisit the dielectric permittivity's temperature dependence, analyzing their DPT and relaxor behaviors and providing a complete description over the whole temperature range. We show that good agreements between theoretical and experimental results can be achieved. To better understand how Ba(Ti1−x Zrx)O3 ceramics changes from DPT to relaxor with increasing x, we also discuss the relation between the fitting parameters and Ba(Ti1−x Zrx)O3's composition and structure, which suggests that the parameters from the statistical model reflect the size of the correlated Ti ions (small clusters or polar nanoregions), which largely determine the behavior of Ba(Ti1−x Zrx)O3 ceramics. [ABSTRACT FROM AUTHOR]

The piezoelectric properties of (K0.5Na0.5)NbO3 (KNN) are normally enhanced by chemical substitutions or doping to form solid solutions. In this study, we report that the piezoelectric properties of KNN and thermal stability of piezoelectric coefficient d33 can be both enhanced by forming the composite of KNN:ZnO. The d33 of KNN:0.2ZnO can be improved to 110 pC/N by introducing the ZnO nanoparticles, which is better than the pure KNN (d33 = 85 pC/N). The Curie temperature (TC = 407°C) remains well comparable to the pure KNN (TC = 408°C). Furthermore, the thermal stability of both remanent polarization (Pr) and piezoelectric parameter (d33) is improved. The enhanced thermal stability could be related to the induced built-in electric field or the enhanced sinterability by the addition of ZnO. The present results may help to optimize the piezoelectric properties of lead-free materials by forming composite. [ABSTRACT FROM AUTHOR]

Crystal structure, piezoelectric, and dielectric properties were investigated in the new lead-free BKT-based piezoelectric ceramics of (1− x)( Bi1/2 K1/2) TiO3- x Bi( Mg2/3 Nb1/3) O3. The morphotropic phase boundary (MPB) of the system between tetragonal and rhombohedral phases lies near the composition of x = 0.02. The optimal piezoelectric property of small-signal d33 is much enhanced to be 96 pC/N ( x = 0.01), which is higher than any other BKT-based compositions. By the introduction of Bi( Mg2/3 Nb1/3) O3, the ceramics exhibit a lower coercive field EC. In addition, a relaxor-like behavior with a frequency-dependent Curie temperature Tm is observed, and high Curie temperature Tm around 380°C is obtained in the investigated system. This study suggests that the piezoelectric properties of BKT can be significantly improved by the means of Bi( Mg2/3 Nb1/3) O3 substitution. [ABSTRACT FROM AUTHOR]

A new lead-free BNT-based piezoelectric ceramics of (1 − x) Bi0.5 Na0.5 TiO3- x Bi( Al0.5 Ga0.5) O3 ( x = 0, 0.02, 0.03, 0.04, and 0.05) were synthesized using a conventional ceramic fabrication method. Their structures and electrical properties were investigated. All the samples show a typical ferroelectric P( E) loops and S( E) curves at room temperature. The optimal properties are obtained at the composition of the x = 0.03. The substitution of Bi( Al0.5 Ga0.5) O3 enhances piezoelectric constant and increases Curie temperature from 58 pC/N and 310°C of pure BNT to 93 pC/N and 325°C of the x = 0.03. The temperature-dependent P( E) loops and S( E) curves of 0.97BNT-0.03BAG indicate that phase transition from ferroelectric to antiferroelectric takes place over a very wide temperature region from 80°C to 180°C. The results show that the introduction of BAG improves the electrical properties of BNT. [ABSTRACT FROM AUTHOR]

(1− x)( K0.5 Na0.5) NbO3- x Ba2 NaNb5 O15 [(1− x) KNN- x BNN, 0 ≤ x ≤0.1] ceramics were prepared by solid-state reaction method. X-ray diffraction analysis of the ceramics revealed that the crystal structure changed from orthorhombic to rhombohedral with increasing BNN content. Dielectric measurement showed that the ceramics exhibited good dielectric temperature stability over a wide temperature range. Basic mechanisms of the conduction and relaxation processes have been investigated using impedance spectroscopy analyses. It was concluded that the conduction and relaxation processes were thermally activated and oxygen vacancies were the possible ionic charge carriers at higher temperatures. [ABSTRACT FROM AUTHOR]

New binary system (1− x) PbTiO3− x Bi( Ni1/2 Zr1/2) O3 ( PT-100 x BNZ) with x ≤ 0.45 were synthesized via solid-state reaction route. A morphotropic phase boundary ( MPB) was identified around x = 0.40 by X-ray diffraction ( XRD) method. The ceramics with MPB composition exhibit enhanced ferroelectric properties. A large piezoelectric coefficient ( d33) up to 400 pC/N was obtained for the PT-40 BNZ, which is comparable with the PbTiO3- BiScO3 ( PT- BS, 450 pC/N).The frequency dependence of dielectric permittivity of PT-40 BNZ shows characteristic of a strong relaxor feature and a transition temperature around 290°C (1 MHz). Temperature effect on the unipolar strain was also investigated. The present system with high d33 is a competitive piezoelectric material, as no expensive oxide is used here compared with the PT- BS. [ABSTRACT FROM AUTHOR]

A piezoelectric system of (1− x) Bi( Ni1/2 Ti1/2) O3- x( Pb(1− y) Sr y TiO3) ( BNT-PST) is developed to have good high temperature piezoelectric properties with much improved resistivity. The crystal structure shows that the phase transformation from tetragonal phase to rhombohedral one is gradually shifted to the composition with high content of PT by the substitution of strontium. The problem of leakage current for the Bi( Ni, Ti) O3- PbTiO3 can be well resolved by introducing the dopant of strontium. Both dielectric loss and DC resistivity can be much reduced not only at room temperature but also high temperature. An optimum composition of 0.53 Bi( Ni1/2 Ti1/2) O3-0.47( Pb0.95 Sr0.05) TiO3 is obtained to have a good potential application of high temperature piezoelectric ( d33 = 205 pC/N, EC = 3.32 kV/mm, Pr = 41.2 μC/cm2). Strontium could be a useful dopant for the studies on the high temperature piezoelectric ceramics in future. [ABSTRACT FROM AUTHOR]

Electronic components are widely used in the field of electronic information. It is more and more important to prepare miniaturized and better performance electronic components. In this work, Sr1−3x/2YxTiO3 (x = 0.005, 0.0075, 0.01, 0.0125) ceramics were prepared by the traditional solid‐phase synthesis method. N2 annealing induces the appearance of lattice defects and free carriers (VO..,e′,Ti3+)$(V_{\mathrm{O}}^{..},\,{\mathrm{e^{\prime}}},\,{\mathrm{T}}{{\mathrm{i}}^{3 + }})$ and defect dipoles (YṠr−VSr′′,Ti3+−Vo..−Ti3+${{\mathrm{Y}}_{{\mathrm{\dot Sr}}}} - {V^{\prime\prime}_{{\mathrm{Sr}}}},{\mathrm{T}}{{\mathrm{i}}^{3 + }} - V_{\mathrm{o}}^{..} - {\mathrm{T}}{{\mathrm{i}}^{3 + }}$). The defect dipoles easily induce the electron‐pinning defect dipole effect and inhibit the movement of free carriers, which can enhance the dielectric constant and reduce the dielectric loss simultaneously. The electrons cannot pass through the insulating grain boundary and accumulate in the conductive grains under an external electric field, forming the internal barrier layer capacitance (IBLC). The ceramic was further refined by high‐energy ball milling to improve the temperature and frequency stability of the ceramic. Under the combined action of rare‐earth doping, atmosphere annealing, and high‐energy ball milling, a dielectric ceramic material with colossal permittivity, low loss, high resistivity, frequency, and temperature stability that meets the ELA X9R capacitor standard was prepared. [ABSTRACT FROM AUTHOR]

The 0.55Bi(Mg1/2Ti1/2)O3–0.45PbTiO3 ceramics exhibit notable dielectric anomalies across three temperature ranges. The low‐temperature anomaly is attributed to a reentrant dipole glass‐like relaxor behavior; the mid‐temperature anomaly results from a ferro‐paraelectric phase transition; and the high‐temperature anomaly is associated with a diffuse phase transition. The system demonstrates favorable piezoelectric, electromechanical, and ferroelectric properties. Specifically, the ceramic presents a piezoelectric coefficient (d33) of 220 pC/N, an electromechanical coupling factor (kp) of 27%, and a remanant polarization (Pr) of 32.5 μC/cm2. Moreover, it maintains an operational capability up to 643 K. The unsaturated P(E) loops are formed through the coupling polarization between polar nanoregions (PNRs) and P4mm ferroelectric domains. By examining the electrical modulus, the dynamic PNRs resulting from ferroelectric phonon localization and the formation of P4mm ferroelectric domains were analyzed. The result reveals a mesoscale coupling relationship between the origin of high‐temperature piezoelectric stability and the dynamics of PNRs, thereby providing noble insights into the (1 − x)BiMeO3–xPbTiO3 system. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the effect of processing parameters and composite regulation on the structure and property relationship of lightweight low‐permittivity Li2O–Al2O3–B2O3 dielectric system. Li2BAlO4 ceramic and (1 − x)Li2BAlO4–xSrTiO3 ceramics were synthesized using a conventional solid‐state reaction method. Thermodynamic analysis, sintering temperature, phase formation, crystal structure, and microwave dielectric properties were investigated. Thermal analysis revealed a melting temperature of 847°C, suggesting a comparatively low temperature for the sintering of Li2BAlO4 ceramics. Li2BAlO4 crystalized into a monoclinic structure with P21/c space group, with [Al2B2O8] rings connected by [BO3] triangles and [AlO4] tetrahedra through Al–O–Al bridges. Dense Li2BAlO4 ceramics with a relative density of ∼97.7% were sintered at 750°C and had optimal microwave dielectric properties with relative permittivity (εr) of 5.13, quality factor (Q × f) of 22 610 GHz, and the temperature coefficient of resonance frequency (τf) of −112.5 ppm/°C. The 0.88Li2BAlO4–0.12SrTiO3 composite ceramic has excellent microwave dielectric properties with εr = 8.83, Q × f = 14 000 GHz, τf = 4.6 ppm/°C. The ceramics also demonstrated an inert behavior with silver electrodes proving its application in low‐temperature cofired ceramic (LTCC) technology. [ABSTRACT FROM AUTHOR]

A piezoelectric system of (1− x) Bi( Ni1/2 Ti1/2) O3- x( Pb(1− y) Sr y TiO3) ( BNT-PST) is developed to have good high temperature piezoelectric properties with much improved resistivity. The crystal structure shows that the phase transformation from tetragonal phase to rhombohedral one is gradually shifted to the composition with high content of PT by the substitution of strontium. The problem of leakage current for the Bi( Ni, Ti) O3- PbTiO3 can be well resolved by introducing the dopant of strontium. Both dielectric loss and DC resistivity can be much reduced not only at room temperature but also high temperature. An optimum composition of 0.53 Bi( Ni1/2 Ti1/2) O3-0.47( Pb0.95 Sr0.05) TiO3 is obtained to have a good potential application of high temperature piezoelectric ( d33 = 205 pC/N, EC = 3.32 kV/mm, Pr = 41.2 μC/cm2). Strontium could be a useful dopant for the studies on the high temperature piezoelectric ceramics in future. [ABSTRACT FROM AUTHOR]

The 0.65Bi(Mg1/2Ti1/2)O3‐0.35PbTiO3 (0.65BMT‐0.35PT) ceramic, nearby morphotropic phase boundary (MPB), between tetragonal and rhombohedral was prepared. Dielectric permittivity dependence of temperature exhibits a re‐entrance dipole glass‐like behavior near room temperature. The behavior was described by the Vogel‐Fulcher law and the new glass model. Furthermore, a phenomenological statistical model was employed to determine the distribution of clusters dependence of temperature. The lattice dynamics of the 0.65BMT‐0.35PT ceramic was estimated by Raman spectroscopy from 298‐723 K. A disruption of ferroelectric long‐range order and an occurrence of local lattice distortion were revealed. The relaxor‐ferroelectric (r‐FE) nature of the 0.65BMT‐0.35PT was characterized by polarization‐electric field P(E). A close relation between the distribution of clusters and ferroelectric properties was established. [ABSTRACT FROM AUTHOR]

Crystal structure, piezoelectric, and dielectric properties were investigated in the new lead-free BKT-based piezoelectric ceramics of (1− x)( Bi1/2 K1/2) TiO3- x Bi( Mg2/3 Nb1/3) O3. The morphotropic phase boundary (MPB) of the system between tetragonal and rhombohedral phases lies near the composition of x = 0.02. The optimal piezoelectric property of small-signal d33 is much enhanced to be 96 pC/N ( x = 0.01), which is higher than any other BKT-based compositions. By the introduction of Bi( Mg2/3 Nb1/3) O3, the ceramics exhibit a lower coercive field EC. In addition, a relaxor-like behavior with a frequency-dependent Curie temperature Tm is observed, and high Curie temperature Tm around 380°C is obtained in the investigated system. This study suggests that the piezoelectric properties of BKT can be significantly improved by the means of Bi( Mg2/3 Nb1/3) O3 substitution. [ABSTRACT FROM AUTHOR]

New binary system (1− x) PbTiO3− x Bi( Ni1/2 Zr1/2) O3 ( PT-100 x BNZ) with x ≤ 0.45 were synthesized via solid-state reaction route. A morphotropic phase boundary ( MPB) was identified around x = 0.40 by X-ray diffraction ( XRD) method. The ceramics with MPB composition exhibit enhanced ferroelectric properties. A large piezoelectric coefficient ( d33) up to 400 pC/N was obtained for the PT-40 BNZ, which is comparable with the PbTiO3- BiScO3 ( PT- BS, 450 pC/N).The frequency dependence of dielectric permittivity of PT-40 BNZ shows characteristic of a strong relaxor feature and a transition temperature around 290°C (1 MHz). Temperature effect on the unipolar strain was also investigated. The present system with high d33 is a competitive piezoelectric material, as no expensive oxide is used here compared with the PT- BS. [ABSTRACT FROM AUTHOR]