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Lead-free piezoelectric ceramics with large strain response and good temperature stability are highly required for actuator applications. However, the search for lead-free ceramics with both enhanced strain and reduced thermal-dependent behavior is a great challenge. In this work, by employing templated grain growth technique and elaborately modulate the phase structure, large unipolar strain of 0.30 %, low strain hysteresis H s ∼ 12 %, along with small strain variation 11.8 % between 20 and 100 °C are achieved in (001) C -oriented (Ba 0.95 Ca 0.05)(Sn 0.04 Ti 0.96)O 3 ceramics, being the optimal level of BaTiO 3 family. It is revealed the ceramics exhibit a coexistence of orthorhombic and tetragonal phases. The inherent piezoelectric anisotropy of orthorhombic phase, the reversible a → c domain switch, along with the refined non-180° domain structures contribute to the remarkable electrostrain characteristic. This study proposed a promising strategy to develop high performance piezoelectric materials for actuator applications. [ABSTRACT FROM AUTHOR]

The development of high-power piezoelectric ceramics with superior piezoelectric properties and broad temperature usage ranges is vital for the thriving progress of electromechanical applications. However, achieving high piezoelectricity, high mechanical quality factor, and temperature stability often presents a trade-off. In this study, we present an advanced ceramic material with excellent high-power piezoelectric properties and superior temperature stability. The piezoelectric coefficient d 33 reaches 348 pC N−1, the electromechanical coupling factor k p is 54%, the mechanical quality factor Q m is 1501, the dielectric loss tanδ is 0.35%, and the d 33 variation is less than 10% within 25–210 °C in 0.05Pb(Mg1/3Nb2/3)O 3 -0.05Pb(Mn 1/3 Sb 2/3)O 3 -0.9Pb 0.95 Sr 0.05 (Zr 0.48 Ti 0.52)O 3 ceramic. The excellent piezoelectricity is attributed to the enhancement of intrinsic ionic displacement and reversible domains wall motion because of symmetry-conforming short-range distribution of oxygen vacancy, while the high Q m is a result of increased domain size and oxygen vacancy. The outstanding temperature stability is related to the stable non-180°domains structure due to the oxygen vacancy pinning effect. These properties hold great potential for advanced applications, particularly for piezoelectric high-power applications requiring constant d 33 over a broad temperature range. [ABSTRACT FROM AUTHOR]

A novel synergistic strategy was used to improve the piezoelectric characteristics of high-temperature piezoelectric ceramics. This work combined three commonly used strategies, constructing the Morphotropic Phase Boundary to reduce energy barriers, changing domain structures impacting macroscopic piezoelectric properties, and adjusting BO 6 octahedral distortions reflecting microstructural changes, thus effectively regulating the piezoelectric behaviors of BiFeO 3 -based ceramics. As a result, the 0.67BiFeO 3 -0.32BaTiO 3 -0.01BiAlO 3 component, exhibiting the maximum distortion of the BO 6 octahedron and the coexistence of macrodomains and nanodomains, achieved the optimal piezoelectric characteristics (d 33 = 225 ± 10 pC N−1, T C = 450 °C). Additionally, the ceramic maintained its high piezoelectric properties even at temperatures as high as 280 °C (346 pC N−1). This study presents a novel collaborative design strategy that combines phase structure, domain structure, and BO 6 octahedral distortion, significantly enhancing the development potential of lead-free high-temperature piezoelectric materials in the future. [ABSTRACT FROM AUTHOR]

This report presents a novel dielectric study of Ba 1-x Y x Ti (1-x/4) O 3 (x = 0, 2 %, 4 %, 6 %, and 8 %) with graphene oxide (GO) via sonication. BaTiO 3 (BT) is a well-known ceramic material with excellent properties, and its temperature stability is crucial for high-temperature applications. However, there is a lack of scientific research exploring this stability at elevated temperatures. This research provides valuable insights into the stability of BaTiO 3 -Yttrium-based ceramics, particularly in conjunction with graphene (BYT@GO), paving the way for potential applications in high-temperature environments. The tetragonality of the structures was identified by powder X-ray diffraction. A uniform grain size was observed for BT@GO, However, BYT@GO (Y% = 2 %, 4 %, 6 %, and 8 %) exhibited a homogeneous morphology and dense microstructure, as observed by scanning electron microscopy. Dielectric measurements were conducted to evaluate the permittivity of the materials as a function of frequency at room temperature. All ceramics demonstrated stable permittivity and low dielectric losses as a function of frequency (<2 × 10−4 for BT@GO, 4 × 10−3 for BYT4%@GO, 6 × 10−3 for BYT6%@GO, and 8 × 10−3 for BYT8%@GO). In addition, BT@GO and BYT 8 %@GO exhibited exceptional dielectric stability at temperatures ranging from 20 to 300 °C. [ABSTRACT FROM AUTHOR]

Core-shell structured fine grain dielectrics, featured with high dielectric constant and wide temperature stability, are essential for the production of high-end MLCCs. In this work, the core-shell structured 100BaTiO 3 - x BaO-2.4MgO-1.0ZrO 2 -0.03MoO 3 -2.25Y 2 O 3 -0.3MnO 2 -2.0SiO 2 (x = 0.5, 1.0, 1.5, 2.0, 3.0, 4.0) ceramics were prepared and the effects of BaO additions on the microstructure and dielectric properties were studied. The resulting ceramics exhibited fine grains (average size 280–300 nm) and demonstrated a high dielectric constant (>1780). Notably, the core-shell structure of the ceramics was affected by the BaO content, with the core volume gradually increasing as the BaO addition grew. This adjustment in composition was found to enhance the temperature stability and reliability of the materials. When the BaO addition reaches 4.0 mol%, the values of Δ C 150 / C 25 °C were effectively suppressed from −22 % to −10.3 % to meet the X8R specification, and the insulation resistivity increased by more than an order of magnitude, reaching a maximum of 11.6 × 1012 Ω m. Our findings highlight the potential of BaO as an effective additive for enhancing the dielectric properties of core-shell structured fine grain dielectrics for high-end MLCCs. [ABSTRACT FROM AUTHOR]

Lead-free dielectric materials with excellent temperature stability are critical to meet ever-increasing demands for practical energy storage applications. Herein, good temperature stability was achieved in AgNbO 3 (AN) antiferroelectric ceramics through texture engineering by using NaNbO 3 (NN) as template. The 3% <001>-oriented NN modified AN (AN-3NN) textured ceramic showed an optimized grain orientation degree of ∼97% by using a templated grain growth technique. Interestingly, the AN-3NN textured ceramic possessed excellent temperature stability for both W rec and energy storage efficiency (η) with respective variations below 0.7% and 0.6% over a temperature range of 20–130 ºC, significantly higher than the non-textured one with respective variations around 7% and 14%. The increased grain orientation and decreased defect concentration for texture engineering contribute to the improved thermal stability. [ABSTRACT FROM AUTHOR]

Ceramic-based dielectric capacitors are showing great potential in advanced high-power applications. However, simultaneous achievement of high energy density (W rec) and temperature stability is still a main bottleneck. Herein, an extraordinary nanoscale structural heterogeneity is developed to promote temperature-stable energy storage in Er/Mn co-doped Bi 0.5 Na 0.5 TiO 3 based ceramics via domain and defect dipoles engineering. The composition-driven domain reconstruction by Er/Mn co-doping can induce internal random fields with rapid response to the electric field, and thus enhance ΔP and η. Meanwhile, the donor-accpetor Er/Mn doping could manipulate defect dipoles coupling to resist the applied field evolution to elevate BDS and η. Besides, the improved relaxor feature and core-shell structure give rise to the enhanced temperature stability. Ceramics with 2 mol % Er 2 O 3 demonstrate high W rec ∼2.79 J/cm3, large efficiency ∼89.4% and outstanding dielectric stability within 70–500 °C. The proposed nanostructural heterogeneity was verified as a promising pathway to manufact temperature-stable energy storage ceramics. The nanoscale structural heterogeneity via domain and defect dipoles strategies is developed to promote temperature-stable energy storage in NBT-based ceramics. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, a ternary solid solution was designed by incorporating varying concentrations of the B-site composite perovskite Ba(Mg 1/3 Ta 2/3)O 3 (BMT) into 0.91Na 0.5 Bi 0.5 TiO 3 -0.09K 0.7 La 0.1 NbO 3 (NBT-KLN-based) ferroelectric ceramics to optimize their energy storage performance. The introduction of BMT disrupted the long-range ordered state of the A/B site in the original perovskite structure, resulting in increased structural disorder and enhanced relaxor characteristics. The viscous polymer processing (VPP) method was employed to attain a significantly denser structure. The 0.10BMT-vpp ceramic has ultimately achieved optimal energy storage performance, along with exceptional temperature and frequency stability. It boasts a high dielectric breakdown strength (BDS) of 440 kV/cm, an ultra-high effective energy storage density (W rec) of 6.7 J/cm3, and an energy storage efficiency (η) of 82%. Moreover, the 0.10BMT-vpp ceramic exhibits robust pulse performance, characterized by an ultra-fast discharge time (t 0.9) of only 77 ns. Furthermore, within the temperature range of −66 °C–354 °C, the temperature coefficient of capacitance (TCC) of the 0.25BMT ceramics undergoes a variation of no more than ±15%, in compliance with X9R specifications (−55 °C–200 °C). The introduction of BMT endows NBT-KLN-based ceramics with remarkable temperature stability and comprehensive energy storage performance, making it a ceramic material with practical potential for industrial applications. [ABSTRACT FROM AUTHOR]

MgTiO 3 –Mg 2 TiO 4 –Na 0.5 La 0 · 5 TiO 3 (MMNL) microwave ceramics were prepared using a conventional solid-state method. The stability of dielectric properties was investigated over a wide range of temperatures. The effects of the composition of the three phases on the microwave dielectric properties of the MMNL ceramics were investigated. The results showed that a high sintering temperature reduces the structural stability and compactness of the ceramics, leading to a deterioration in their dielectric properties. The addition of MgTiO 3 effectively increased the vibration peak intensity of the [TiO 6 ] oxygen octahedra but reduced the relative density, leading to a decrease in the Q × f value. The τ f value approached zero in a wide temperature range (−40–120 °C) by regulating the phase compositions of the MMNL ceramics. In particular, the 0.21MgTiO 3 -0.653Mg 2 TiO 4 -0.137Na 0 · 5 La 0 · 5 TiO 3 ceramic sintered at 1440 °C for 6 h exhibited superior microwave dielectric properties: ε r = 17.5 (8.83 GHz), Q × f = 62,800 GHz, and τ f = −0.35 ppm/°C. [ABSTRACT FROM AUTHOR]

In this paper, Bi 2 O 3 doped BaTiO 3 -0.01MgO-0.01Nb 2 O 5 ceramics are designed to increase dielectric constant, reduce dielectric loss and improve temperature dielectric stability through inducing defects, and are prepared by flash sintering method to inhibit the volatilization of Bi element and ensure the element ratio. The microstructure, polarization mechanisms, dielectric properties and conduction mechanism of the ceramics are studied. The doping of Bi 2 O 3 can enhance the relaxation behavior and dielectric properties. The defects evolution in BaTiO 3 -0.01MgO-0.01Nb 2 O-0.01Bi 2 O 3 ceramics are studied. The results show that the BaTiO 3 ceramics doped with different amounts of Bi 2 O 3 can form defect dipoles { [ Bi Ba ∙ ‐ Mg Ti ″ ‐ Bi Ba ∙ ] ×, [ Nb Ti ∙ ‐ V Ba ″ ‐ Nb Ti ∙ ] ×, [ Mg Ti ″ ‐ V O ∙ ∙ ] ×} and oxygen vacancy, which enhance the short-range transition within the grain and inhibit the movement of free electrons at the grain boundary. The ceramics have excellent room temperature properties, high dielectric constant (ε r = 2894) and low dielectric loss (tan δ < 0.03). The ceramics have superior temperature stability and satisfying the EIA X8R (Δ ε r / ε 25 ≤ ±15 %, over the temperature range from −55 °C to 150 °C). It is found that flash sintering can effectively guarantee the stoichiometric concentration of bismuth element and obtain good properties of ceramics. This study demonstrates the potential of Bi 2 O 3 doped BaTiO 3 -based ceramics synthetized by flash sintering as high-performance electronic device materials. [ABSTRACT FROM AUTHOR]

Developing high performance and pollution-free energy storage devices is crucial for the development of the energy industry. The Sm(Mg 0.5 Ti 0.5)O 3 -modified (Bi 0.5 Na 0.5) 0.7 Sr 0.3 TiO 3 ((1- x)BNST– x SMT, x = 0.00–0.15)) relaxor ceramics were synthesized by using a traditional solid-state sintering method. The phase structure, microstructure, dielectric spectrum, and energy storage properties were studied. The x = 0.10 sample obtained an energy storage density of 4.33 J/cm3 under an electric field of 290 kV/cm, while the energy storage efficiency reached 80 %. In addition, the variation of energy storage density remains within ±4 % and the energy storage efficiency is above 80 % at a frequency of 1–100 Hz and a temperature of 25–120 °C, respectively, indicating that the x = 0.10 sample has good stability in both temperature and frequency. The energy storage decreases slightly with increasing temperature and frequency, which originates from the migration of intrinsic charge carriers and the weakening of the interaction force between cations and anions. In addition, the x = 0.10 sample exhibits good fatigue resistance, with little change in the ferroelectric loop after 105 cycles. This performance advantage indicates that the (1- x)BNST- x SMT ceramic systems have great potential in the field of high energy storage. [ABSTRACT FROM AUTHOR]

The effect of Mn on ZnO–Bi 2 O 3 (ZnBiO) based varistor ceramics sintered below 900 °C has not been fully understood due to the conventional ZnBiO-based varistor ceramics usually being sintered at temperatures higher than 900 °C. Therefore, (99.5-x) ZnO+0.5Bi 2 O 3 + x MnCO 3 (x = 0, 1, 2, and 3; all in mole ratio) ceramics were prepared by solid-state sintering at 875 °C for 3 h to study the effect of Mn on the microstructure, electrical nonlinear properties and their stability within the range of 25–100 °C. The results show that doping MnCO 3 results in the formation of Mn 3 O 4 and Bi 12 MnO 20 secondary phases within the sintered samples. Mn 3 O 4 mainly exists at grain boundary as particle phase, restricting the growth of ZnO grains during sintering. The presence of Bi 12 MnO 20 indicates MnCO 3 may enhance the sintering of ZnBiMnO ceramics by increasing the amount of Bi-rich liquid phase. MnCO 3 effectively improves the electrical nonlinear properties of ZnBiMnO varistor ceramic and their stability against the variations in ambient temperature. The 2 mol% MnCO 3 doped ZnBiMnO varistor ceramic shows the best electrical nonlinearity, with a nonlinear coefficient, a breakdown voltage and a leakage current density of 53.61, 503.11 V/mm, and 2.85 μA/cm2 respectively. This study may improve our understanding of the effect of Mn on the low-temperature sintered ZnBiO based varistor ceramics, and provide a promising candidate material for manufacturing low-cost ZnO based varistor. [ABSTRACT FROM AUTHOR]

Lead-based piezoelectric ceramics are the preferred material for commercial piezoelectric ceramic actuators due to their high performance and irreplaceability. However, the operating temperature (<100 °C) and strain (0.1 %∼0.2 %) of lead-based piezoelectric ceramics are still limited. Achieving large strain in a wide temperature range remains challenging. In this paper, a new strategy is proposed to effectively increase the strain value of lead-based piezoelectric ceramics through domain engineering. The new x PbTiO 3 -(0.97- x)PbZrO 3 -0.03(La 0.1 Sr 0.80.1)TiO 2.95 (x PT-PZ-LST) ternary piezoelectric ceramic system reaches a strain value as high as 0.5 % and exhibits extremely high temperature stability (13 %) in the range of 25–230 °C. By fine-tuning the content of PT components, the average length and width of a typical tetragonal domain are transformed from 800 nm to 80 nm (long and thin) to 300 nm and 200 nm (short and wide), relatively. From the experimental results of PFM and Rayleigh analysis, the high strain can be attributed to the synergistic effect of the reduced coercive field (E c), enhanced micro-region response, and regulated domain morphology, which ensures that high intrinsic and extrinsic contribution can be achieved at the same time. In this paper, a new strain regulation method is provided for lead-based piezoelectric ceramics, and a valuable large strain material is obtained via domain engineering. [ABSTRACT FROM AUTHOR]

Lead-free capacitors operating at low electric fields with high-energy density and high efficiency are critical for advanced electronic systems and innovative pulsed power applications. In this work, single tetragonal phase dielectric ceramics with high-energy storage density and high efficiency are prepared using the solid-state method. The co-substitution of Ba2+, Sm3+, and Mn4+ on the Sr 2 NaNb 5 O 15 substrate enhances low-temperature relaxation behavior and polarization modulation due to order/disorder distribution and polar nanoregions (PNRs) in the structural distortion system. Ferroelectric tests revealed that the optimized Sr 1.83 Ba 0.16 Sm 0.01 NaMn 0.01 Nb 4.99 O 15 tungsten bronze system has large energy storage density (W rec = 4.432 J cm−3) and high efficiency (η = 84.3 %) at a low electric field (250 kV cm−1). In addition, the temperature-dependent permittivity results for the Sr 1.82 Ba 0.165 Sm 0.015 NaMn 0.015 Nb 4.985 O 15 and Sr 1.81 Ba 0.17 Sm 0.02 NaMn 0.02 Nb 4.98 O 15 ceramic samples demonstrated that they are X9R capacitor-compatible. Finally, Sr 1.83 Ba 0.16 Sm 0.01 NaMn 0.01 Nb 4.99 O 15 has a current density (C D) of ∼797.77 A cm−2 and power density (P D) of ∼87.75 MW cm−3 with a very fast discharge time (t 0.9 < 60 ns). It is worthy to note that all the components display excellent temperature stability (ΔW dis < 10 %) in the over-damping test. Thus, this work provides an avenue to obtain dielectric ceramic materials with potential application value in innovative pulse power components. [ABSTRACT FROM AUTHOR]

In this study, the Pb(Yb 1/2 Nb 1/2)O 3 (PYN) relaxor with high Curie temperature (T C ∼300 °C) was incorporated into PbZrO 3 -PbTiO 3 (PZ-PT) ceramics to form 0.1PYN-(1- x)PZ- x PT ternary ceramics, and their phase compositions were systematically investigated, providing the more detailed phase diagrams, dielectric, piezoelectric, and ferroelectric properties. Excellent piezoelectric performance (d 33 ∼ 450 pC/N, d 33 * ∼714 pm/V), with high coercive field (E C ∼17.5 kV/cm) and T C (∼398 °C) were simultaneously achieved in the 0.1PYN-0.41PZ-0.49PT composition near the morphotropic phase boundary (MPB). The value of d 33 × E C , which exhibits higher than commercial PZT ceramics, indicates its suitability for high-field excitation devices. Additionally, the temperature stability of the resonant frequency (f r) is qualitatively studied by analyzing the main factors influencing f r from a theoretical perspective. Superior stability is achieved in the 0.1PYN-0.38PZ-0.52PT composition (T C ∼ 405 °C) with tetragonal phase, and the temperature coefficient of resonant frequency (Δ f r / f r 25 °C) remains within 0.5% up to 300 °C, far outperformance than previous reports. [ABSTRACT FROM AUTHOR]

The (1-x)CaZrO 3 -xSrTiO 3 solid-solution thin films were prepared with different compositions from x = 0.05 to x = 0.45. The as-prepared thin films experienced such a crystal structure transition process from orthorhombic to pseudo cubic and then to cubic as the x increases. Among the as-prepared films, the smallest expansion ratio of lattice volume with temperatures, and the highest temperature stability of dielectric response and leakage current density at high voltage were found in the x = 0.3 thin films. The relationship between the tolerance factor and the temperature stability was analyzed from the crystal structure dependence of the absorbed thermal energy distribution. Finally, the x = 0.3 thin films were developed into thin-film capacitors, which showed high DC resistance and uniform capacitance properties. The result also shows that high temperature stability of the perovskite-type paraelectric thin films could be realized through the phase boundary design, and further improved by optimizing the temperature stability of the lattice structure. [ABSTRACT FROM AUTHOR]

High-performance piezoelectric ceramics with temperature stability can significantly enhance the functionality of transducers and sensors across a range of piezoelectric device applications. In this study, we investigated ceramics composed of 0.16Pb 0.92 Ba 0.08 (Mg 0.5 W 0.5)O 3 -0.84 Pb(Zr 0.43 Ti 0.57)O 3 (PBMW-PZT) with varied Nb 2 O 5 content. Notably, the ceramic doped with 1.0 wt% Nb 2 O 5 exhibited superior piezoelectric properties (d 33 ∼ 596 pC/N, k p ∼ 67%, and T c ∼ 284 °C). Moreover, this ceramic demonstrated a stable performance with variations below 10% in the temperature range from 20 °C to 240 °C, surpassing many commercially available PZT-based ceramics. A combination of XRD, SEM, ferroelectric studies, and other in situ analytical methods indicated that this heightened piezoelectric response arises from a marked increase in reversible domain wall movement. The temperature-responsive Raman spectra suggest that the material's temperature stability primarily stems from its inherent structural integrity. Given these findings, the ceramic material in question emerges as an optimal choice for applications in piezoelectric devices, especially transducers and sensors. [ABSTRACT FROM AUTHOR]

In this work, 5 wt‰ Li 2 CO 3 -doped 0.88Ba 0.8 Sr 0.2 TiO 3 -0.12BiMeO 3 (BST-BMe+5‰Li 2 CO 3 , Me = Al3+, Ga3+, Ta5+, and In3+) ceramics were fabricated using solid phase sintering approach. The impacts of different B-site Me ions on the crystalline structure, permittivity stability, energy density, and energy storage efficiency of these ceramics were studied. The XRD results revealed that the mixed tetragonal (T) and pseudo cubic (pC) phase structure was obtained for all the samples. The In/5‰Li 2 CO 3 sample exhibits the optimal energy density of W rec = 1.04 J/cm3 and the energy efficiency of η = 96% at 170 kV/cm. Meanwhile, the sample shows outstanding temperature stability satisfying the EIA-X8R criteria, which is ascribed to the combined roles of defect dipoles and large lattice distortion. Li 2 CO 3 plays a key role in reducing the sintering temperature, raising the breakdown strength, enhancing the relaxation characteristics, and improving the thermal stability of energy efficiency of the ceramics. [ABSTRACT FROM AUTHOR]

Lead-based Pb(Zr, Ti)O 3 ceramics have been widely applied in piezoelectric actuators, and yet high temperature stability and large strain have been pursued for further application. In this work, a novel PbZrO 3 –PbTiO 3 -(Bi 0.5 Na 0.5)TiO 3 (PZ-PT-BNT) piezoelectric ceramic is designed and prepared by solid-state route. It is found that the introduction of BNT constituent enhances the relaxation behavior of PZ-PT ceramic, inhibits the abrupt change in dielectric properties near Curie temperature, and increases the proportion of tetragonal phase with high temperature stability. Meanwhile, the patterns of electric domains are intentionally modified by adjusting composition of PZ-PT-BNT. Short and broad electric domains in PZ-PT-0.03BNT ceramic are observed by piezoresponse force microscopy, which are insensitive to temperature and have faster response under electric field, contributing to strain characteristics. As a result, through integrating phase structure and electric domain configuration, a strain of 0.21% and excellent temperature stability where the variation of strain is less than 8% in the temperature range of 25–250 °C are achieved in PZ-PT-0.03BNT ceramic. The findings provide an effective strategy for improving the strain stability of PZ-PT-based piezoelectric ceramics, and demonstrate that PZ-PT-BNT ceramics have potential application prospects in high-temperature piezoelectric actuators. [ABSTRACT FROM AUTHOR]

The temperature stability and temperature stability range of barium titanate-based pulse energy-storage ceramics were modified by Bi 2 O 3 tailoring in (Ba 0.98- x Li 0.02 Bi x) (Mg 0·04 Ti 0.96)O 3 (x = 0, 0.025, 0.05, 0.075, 0.1) and (Ba 1.03-1.5 x Li 0.02 Bi x) (Mg 0·04 Ti 0.96)O 3 (x = 0.125, 0.15, 0.2, 0.25) ceramics. Excellent pulse energy-storage performances of ceramic films are achieved via the new dual priority strategy of establishing cationic vacancies and forming a liquid phase. The dielectric constant plateau appears due to the cubic phase and space charges. Outstanding temperature stability, frequency stability and antifatigue performance are obtained in the ceramics, and their variations are all less than 15%. The comprehensive energy-storage properties with dual priority parameters of energy-storage density and efficiency of 3.13 J/cm3 and 91.71%, accompanied by an excellent pulse discharge energy density of 2.48 J/cm3, current density of 1313.23 A/cm2 and power density of 195.26 MW/cm3 are gained at x = 0.1. The perfect pulse energy-storage performances as well as ultrahigh stability are correlated with synergistic effects of multiphase coexistence, cubic phase, liquid-phase sintering, grain size, ceramic resistance, space charges and polar nanoregions. The comprehensive parameters indicate that the (Ba 0·88 Li 0·02 Bi 0.1) (Mg 0·04 Ti 0.96)O 3 ceramics have potential application in high precision fields. [ABSTRACT FROM AUTHOR]

The discovery and characterization of new alginate lyases with high activity and stability have been the research topic in utilization of alginate biomass. Herein, we characterized a new Thalassotalea algicola -derived polyM-preferred PL6 family alginate lyase TAPL6 with two-domains (catalytic domain NTD and non-catalytic domain CTD). TAPL6 is a bifunctional enzyme that could endolytically degrade polyM, and could exolytically degrade polyG. It could degrade alginate in a hybrid action mode. The specific activities of polyM, polyG and sodium alginate of TAPL6 were 7174 U/mg, 4140.2 U/mg and 414.3 U/mg, respectively. The optimal temperature and pH for TAPL6 are 25 °C and 8.0, respectively. Deletion of CTD resulted in a loss of 99.8%− 98.2% of TAPL6 activity and a decrease in pH adaptability, but greatly improved the activity and temperature stability above 30 °C. The CTD truncation is more resistant to metal ions than TAPL6, and the promotion effect of Ca2+ on the activity is stronger. Deletion of CTD results in a change in the action mode of TAPL6 to an endo-mode. In addition, the integrity of the linker between NTD and CTD is very important for the soluble expression of recombinant protein, and the complete linker is beneficial to the catalytic activity of NTD. This study provides a new tool enzyme for the production of alginate oligosaccharides, and explores the role of the non-catalytic domain CTD in the PL6 family alginate lyases, providing a rational design basis for the PL6 family alginate lyases to change the enzymatic properties and action mode. [Display omitted] • Biochemical characterization of a new PL6 alginate lyase and its domain truncations. • Function of CTD structural domain in the whole enzyme. • Action mode of TAPL6 and the effect of CTD on product distribution and action mode. [ABSTRACT FROM AUTHOR]

The search for a suitable donor dopant to improve the piezoelectric response of BiScO 3 -PbTiO 3 (BS-PT) piezoelectric ceramics without sacrificing temperature stability is crucial for developing high-temperature piezoelectric materials for the application in the elevated temperature. In this study, the effects of Sb5+ donor doping on the microstructure, dielectric, ferroelectric, piezoelectric and electromechanical properties of the BS-PT ceramics were investigated. It was found that the Sb5+ dopant acts as the grain growth inhibitor, resulting in a dense and fine-grain microstructure. An enhanced piezoelectric properties d 33 of 535 pC N−1 with a high T c of 440 °C was simultaneously achieved in 0.25 mol%Sb5+ doped BS-PT (BSPT-0.25Sb) ceramic. The results of in-situ piezoelectric constants and electromechanical coupling coefficients as a function of temperature indicate that the BSPT-0.25Sb ceramic has a high depolarization temperature T d of 400 °C, which is much higher than those of the most widely used PZT-based piezoelectric ceramics. Furthermore, BSPT-0.25Sb ceramic has much higher resistivity and lower dielectric loss than PZT-4 and PZT-8 at high temperature. The excellent piezoelectric properties and thermal stability of the BSPT-0.25Sb ceramic indicate that it is a promising piezoelectric material for high-temperature applications. [ABSTRACT FROM AUTHOR]

Multilayer ceramic capacitors (MLCCs) had become an important component of many electronic devices on account of its miniaturization, high capacitance and reliability. To satisfy the requirements of MLCCs, the temperature–insensitivity and dielectric properties of the dielectric ceramics were urgent to be enhanced. In our work, (1– x)K 0.5 Na 0.5 NbO 3 – x Bi(Li 0.5 Nb 0.5)O 3 (abbreviated to KNN– x BLN) were successfully synthesized by traditional solid state reaction method. On the one hand, the doping BLN induced the diffused phase transition and broadened the dielectric anomaly peaks, which improved the temperature insensitivity of KNN-based ceramics. On the other hand, the nanosized grains and dense microscopy boosted the breakdown electric field. Ultimately, the KNN–0.175BLN samples presented the excellent dielectric properties with high dielectric constant (1735) and low dielectric loss (1.9%) at room temperature with a wide temperature stability range (–62 – 300 °C), which exhibited the wider temperature stability range than X9R specification. Meanwhile, the x = 0.175 samples also achieved a high recoverable energy storage density of 3.71 J/cm3 under the breakdown electric field of 360 kV/cm. The designed KNN–based dielectric materials were expected to be applicable to the energy storage capacitor with standed high operating temperature. • The BLN doping induced the diffused phase transition and broaden the dielectric peaks of KNN–based ceramics. • The KNN–0.175BLN samples presented the high ε of 1735 and wide temperature stability range from −62 to 300 °C. • The KNN–0.175BLN ceramics achieved high recoverable energy storage density of 3.71 J/cm3. [ABSTRACT FROM AUTHOR]

The comprehensive control of dielectric properties and temperature stability is the focus of BaTiO 3 -based ceramics with non-reducibility. For this purpose, BaTiO 3 –0.02MgO–0.02Y 2 O 3 –0.04CaZrO 3 –xMnO 2 (x = 0, 0.005, 0.01 and 0.015) ceramics were prepared by the solid-state method and sintered in a reducing atmosphere. When x = 1.5 mol%, high dielectric constant (ԑ r ∼ 3644), large insulation resistivity (ρ v ∼ 2.07 × 1011 Ω cm), and low dielectric loss (tanδ ∼ 0.011) were obtained in ceramics, which demonstrated the superior potential of current studies. The effects of multivalent Mn-ion doping on the phase transition, dielectric characteristics, and defect polarization were systematically investigated based on the experimental results and first-principle calculations. The change of dielectric properties was related to the formation of new defect dipoles ([ M n T i ′ − Y B a • ] and [ M n T i ″ − 2 Y B a • ]). According to the first-principle calculations, the deformation of ceramic structures and the nonuniform distribution of electron density lead to the weakening of chemical bonds and the enhancement of carrier transitions. The interfacial polarization associated with the long-range hopping of oxygen vacancies is the main source of high dielectric constant for Mn15 ceramic samples. Furthermore, all ceramics showed excellent temperature stability and satisfied the EIA X8R standard (−55 °C–150 °C, ΔC/C 25°C ≤ ±15%), which can be explained by the "core-shell" structure. The effect of internal defect structure on polarization mode presented in this work can be applied to the study of BaTiO 3 -based dielectric ceramics. The results have excellent application potential in the BME-MLCC industry. [ABSTRACT FROM AUTHOR]

Lead-free ceramics with prominent energy storage properties are identified as the most potential materials accessed in the dielectric capacitors. Nevertheless, high recoverable energy storage density (W rec), large energy storage efficiency (η) and preferable temperature stability can hardly be met simultaneously. The Bi(Zn 2/3 Ta 1/3)O 3 and NaNbO 3 components are doped in KNN ceramics to substantiate the reliability of this tactic. A high recoverable energy density (W rec) of ∼ 4.55 J/cm3 and a large energy storage efficiency (η) of ∼ 87.8% are acquired under the dielectric breakdown strength (DBS) of ∼ 375 kV/cm, along with a splendid thermal stability (W rec variation: ∼ 2.3%, η variation: ∼ 4.9%) within the temperature range of 20 ℃− 120 ℃. This article demonstrates that the KNN-based ceramics integrate high energy storage properties and outstanding temperature stability at the same time, which broadens the application fields of pulse power systems. [ABSTRACT FROM AUTHOR]

To acquire electric capacitors with enhanced energy storing performance, a composition embellishment and process improvement strategy were adopted. A serial of lead-free (Ba 0.875 Bi 0.125) (Li 0.0625 Nb 0.0625 Ti 0.875)O 3 (BBLNT) ceramics were prepared via both conventional solid-state method and viscous polymer processing technology (VPP). The BBLNT-VPP ceramics achieved an ultrahigh energy storing density of 5.34 J/cm3 and a reasonable efficiency of 88% at 470 kV/cm. In addition, the ceramics have particularly extraordinary temperature stability of W rec 2.8 J/cm3, △η 2.5% over 30–150 °C, as well as excellent frequency stability with W rec 3.46 J/cm3, η 88%, △W rec ±2.7% and △η ±4% in the range of 5–300 Hz. Meanwhile, the power density of the ceramic remained above 84.04 MW/cm3 when the temperature was increased from room temperature to about 150 °C, indicating the ceramics possess great promise. Therefore, the BBLNT-VPP ceramics with excellent properties obtained in this work can be potentially applied in dielectric capacitors. [ABSTRACT FROM AUTHOR]

In this work, doping and composite are simultaneously utilized to improve the T m of 0.55 Pb(Ni 1/3 Nb 2/3)O 3 -0.135PbZrO 3 -0.315PbTiO 3 ceramic by adding ZnO (PNN-PZT: x ZnO). It is found that Zn ions prefer to substitute for Ni ions, making Ni ions spontaneously crystallize at grain boundaries in the form of an oxide. Moreover, limited by the solid solubility, superfluous ZnO particles also stay at grain boundaries with the increasing ZnO content. Thus, triple contribution of ions substitution, local stress fields and electric fields coexist in the PNN-PZT: x ZnO ceramics with high ZnO content, dramatically improving the T m from 102 °C to 171 °C. The excellent comprehensive electromechanical performance is obtained in the sample with x = 0.05: d 33 ∼ 824 pC/N, d 33 * ∼1059 p.m./V, T m ∼140 °C, E c ∼5.2 kV/cm, Q m ∼87. As the ceramic is heated to 125 °C, its k 33 and d 33 values still remain ∼67% and ∼80% of the corresponding room temperature values as evidenced by in - situ temperature stability measurement. Our results indicate that PNN-PZT: x ZnO ceramics are the most promising candidates to develop high-performance medical ultrasound transducers for imaging, meanwhile, provide a fresh design strategy to optimize the performance of the piezoelectric ceramics. [ABSTRACT FROM AUTHOR]

High performance lead–free ceramic capacitors are a key factor in the practical application of new pulsed power systems, which require higher energy storage density, energy efficiency, and the ability to operate stably in extreme environments. Therefore, this paper proposes a strategy for multiphase engineering of induced polar nanoregions (PNRs) and the design of (1- x)(0.94Bi 0.5 Na 0.5 TiO 3 –0.06BaTiO 3)– x LaMg 0.5 Ti 0.5 O 3 lead–free ceramics. The content of the tetragonal (T) and rhombohedral (R) phases is controlled by adjusting the content of LaMg 0.5 Ti 0.5 O 3 to enhance the energy storage properties of the ceramics. The introduction of the broadband oxide MgO and the rare earth ion La3+ optimizes the grain size of the ceramics to achieve higher breakdown strengths, which can be confirmed in the first principles calculations. The higher breakdown strength leads to a larger saturation polarization further resulting in a higher recoverable energy density. The introduction of these dopants causes structural disorder, resulting in enhancement of the relaxation properties and a thin P–E loop, thus achieving an extremely high recoverable energy density (3.72 J/cm3) and energy efficiency (82.3%). At the same time, the ceramic has a high temperature stability (η varies less than 3.9%) and frequency stability (η varies less than 3.7%). All of the above work shows that the design has great potential for application in the field of pulsed capacitors. [ABSTRACT FROM AUTHOR]

In this work, the effects of neutron irradiation and high temperature on the magnetic properties and structure of Sm 2 Co 17 permanent magnets (PMs) were investigated. The phase composition in Sm 2 Co 17 PMs does not change after neutron irradiation with fluence of 5 × 1014n/cm2. The magnetic domain structure and Mössbauer spectra of Sm 2 Co 17 PMs were almost kept the same after neutron irradiation. The neutron irradiation almost does not influence the intrinsic coercivity and magnetic flux ϕ of Sm 2 Co 17 PMs. When temperatures increase from room temperature to 300 °C, intrinsic coercivity H cj , remanence B r and maximum energy product (BH) max have 52.8 %, 5.6 % and 15.4 % deterioration, respectively. Magnetic flux ϕ decreases by 4.1 %. When temperature increases to 550 °C, compared with room temperature, H cj , B r and (BH) max decrease 88.8 %, 21.8 % and 54.3 %, respectively. ϕ has a 40 % deterioration. [ABSTRACT FROM AUTHOR]

The rutile TiO 2 ceramics substituted with acceptor and donor ions are regarded to be promising candidate materials for energy storage because of their colossal permittivity (CP). In this work, a good CP performance (ϵ r >104) was achieved in all of (Cu 0.5 W 0.5) x Ti 1- x O 2 (CWTO x) ceramics fabricated by a traditional solid reaction method. Remarkably, CWTO 0.015 ceramic obtained an acceptable temperature stability accompanied a low dielectric loss (tan δ < 0.1) within a broad frequency/temperature range, which satisfies the application requirement of X8R. Two kinds of abnormal dielectric relaxation at low and high temperature region were interpreted by interface polarization and ionization of oxygen vacancies, respectively. Data of complex impedance combined XPS and EPR results proved that the IBLC effect is dominant to the CP performance of CWTO x ceramics. The finding in this work is expected to promote the further development and application of CP materials. [ABSTRACT FROM AUTHOR]

Trilayer architectures were designed and investigated to further improve the microwave dielectric properties of the Ba(Mg 1/3 Nb 2/3)O 3 (BMN) – Mg 4 Nb 2 O 9 (MN) system, namely, to achieve temperature stability while maintaining high- Q. The calculated phase fractions in randomly distributed (1- x)BMN- x MN ceramics deviated from the designed composition (where the composition with x = 0.045, 0.056, 0.125 and 0.98 was respectively referred to as S1, S2, S3 and MN'), thus allowing it difficult to obtain near-zero τ f as expected. In densification studies, doping a little MN was shown to effectively promote the sintering of BMN and provide the possibility for layer-cofired optimization. Fortunately, undesired differences in composition and performance could be suppressed with the weakened ion diffusion occurring at narrow interfaces with a width of ∼2.5 μm in the S1/MN'/S1 trilayer architecture. Considering the influence of cofired compatibility and stress of dielectric layers, the compositionally optimized S3/MN'/S3 ceramics sintered at 1340 °C exhibited excellent microwave dielectric properties of ε r = 21.95, Q × f = 110,482 GHz (f 0 = 6.870 GHz), and τ f = 0.965 ppm/°C. Moreover, the dielectric response mechanism of layered ceramics was clarified by establishing the relationship between the layered architecture, dielectric properties and electric field distribution using the finite element method and high-frequency structure simulator (HFSS). This suggests that layered architectures like S1-3/MN'/S1-3 could effectively compensate for the dielectric properties and hold a promising application prospect of 5G wireless communication. [ABSTRACT FROM AUTHOR]

Temperature stability and strain hysteresis are two extremely important parameters for high-precision piezoelectric actuators applications. Piezoelectric ceramics with high temperature stability and low strain hysteresis are eagerly expected. In this work, the strain characteristics of x Bi(Zn 1/2 Ti 1/2)O 3 -(1- x)(0.55PbZrO 3 -0.45PbTiO 3) [ x BZT-(1- x)(PZ-PT)] ferroelectric ceramics were investigated meticulously, and temperature-insensitive strain response and low strain hysteresis were simultaneously acquired at x = 0.15. The strain variation was less than 10% in the temperature range of 30–100 °C and the strain hysteresis was only 6% at 7 kV/mm. The incorporation of BZT transforms the crystal structure of PZ-PT ceramics from morphotropic phase boundary (MPB) to tetragonal phase. Strong relaxation behaviors occurred and a large piezoelectric coefficient of 500 p.m./V at 2 kV/mm were obtained at x = 0.15. The above merits will make this ferroelectric ceramic an ideal material for the fabrication of high-precision actuators and their use in harsh environment conditions. [ABSTRACT FROM AUTHOR]

Piezoelectric strain and its temperature stability of KNN-based ceramics sintered in reducing atmosphere are improved simultaneously via defects design of Mn doping. MnO and MnO 2 as raw materials have an impact on defects in KNN-based ceramics. When the dopant changes from MnO to MnO 2 , the defects (Mn Nb ′ ′ ′ , Mn K · , Mn Na ·) concentration decrease and defects (Mn Nb ′) increase. Defect dipoles (Mn K · - V K ′ , Mn Na · - V Na ′ , Mn Nb ′ ′ ′ - V o ··) in poled and aged 0.94 K 0.48 Na 0.52 Nb 0.96 Ta 0.04 O 3 -0.06BaZrO 3 + 0.08MnO ceramics form a strong restoring force for domain switching, which enhances the reversibility of the non-180° domains switching and then significantly improves piezoelectric strain. The stable defect dipoles (Mn K · - V K ′ , Mn Na · - V Na ′) form so that the reversibility of the non-180° domains switching can be preserved to high temperature. This defect dipoles design provides a general method to achieve large piezoelectric strain (582 pm/V@20 kV/cm) and excellent temperature stability (T 90 =210 °C). [ABSTRACT FROM AUTHOR]

The Mg 2 TiO 4 - x wt% LiF–2CaF 2 –2B 2 O 3 (LCB, 3.0 ≤ x ≤ 10.0) ceramics were fabricated to study the relationship among LCB additive and the sintering behavior, phase composition, micro-structure and dielectric performance of ceramics in this study. The sintered ceramics are mainly Mg 2 TiO 4 phase, accompanied by small amount of second phase CaTiO 3 and Mg 3 B 2 O 6. They are generated from the chemical reaction of CaF 2 and B 2 O 3 with the matrix material, respectively. Appropriate LCB additive significantly enhanced sintering ability and dielectric performance of Mg 2 TiO 4 -based ceramics. Sintered at 1175 °C, Mg 2 TiO 4 -7.5 wt% LCB ceramics exhibited a dielectric performance: ε r of 15.3, Q × f of 32 950 GHz and τ f of +1.96 ppm/°C, which is expected to be an alternative material for communication component. [ABSTRACT FROM AUTHOR]

In this investigation, La 2 O 3 was doped into 0.85(0.65BF-0.35BT)-0.15Sr 0.7 Bi 0.2 TiO 3 (BF-BT-SBT) to form a solid solution with relaxation ferroelectric properties. The dielectric breakdown strength (BDS) of 1% mole of La doping was 220 kV/cm, the maximum recoverable energy storage (W rec) was 2.35 J/cm3, and the energy storage efficiency (η) was 71%. The relationship between ceramic properties and microstructure was investigated in detail. Doping with La has the following main features: (1) The dissolution of La3+ ions in the A position of the original perovskite structure reduced the concentration of oxygen vacancies in the lattice and played a role of compensating the defects. (2) The dielectric loss of ceramics was reduced, the impedance was greatly increased, and the specimen exhibited a high-temperature stability: a maximum W rec of 4.04 ± 1.7% J/cm3 in 30–130 °C. (3) The core–shell–like with single phase structure in La-doped ceramics had been successfully observed, which may become a strategy for preparing high-performance ceramics. Higher BDS and denser structures were obtained in 0.01 La ceramics by further optimizing the preparation of the above compositions by the viscous polymer process (VPP). The BDS of 0.01La ceramics prepared by VPP reached 480 kV/cm, the effective energy storage density reached 6.15 J/cm3, and the η was about 81%. This made La-doped 15SBT (chemical composition of BF-BT-SBT + La 2 O 3) ceramics become a potential candidate material for energy storage devices. [ABSTRACT FROM AUTHOR]

Bi 0.5 Na 0.5 TiO 3 -based ceramics are chemically modified to easily generate large strains, which have been widely studied in the field of lead-free piezoelectric materials and actuators. However, the large temperature dependence of their electrically induced strains limits the practical applications. In this paper, 0.94Bi 0.5 Na 0.5 TiO 3 -0.06BaTiO 3 - x wt%Sb 2 O 3 (BNBT6- x wt%Sb 2 O 3) lead-free ceramics were prepared by the conventional solid-phase method. When x = 0.6, a strain of 0.47 % was obtained at room temperature, and the strain fluctuation was only 10.1 % over a wide temperature range from 20℃ to 140℃. Furthermore, the strain essentially did not decay after 105 cycles, which had high temperature stability and fatigue stability while maintaining a large strain. The large strain and excellent fatigue performance are attributed to the reversible transition between the relaxor and ferroelectric state under the applied electric field. The remarkable stability of strain across temperatures was attributed to a synergistic interplay between two opposing effects: the negative temperature dependence of lattice distortion caused by the electric field, and the positive temperature dependence of the resulting strain itself. This interplay was believed to be facilitated by the presence of disordered and short-range nanodomains within the material. The present study achieved excellent comprehensive performance in strain and thermal stability, which helps to promote the development and applicability of lead-free actuators over a wide temperature range. • A large strain is 0.47 % with a fluctuation of only 10.1 % between 20℃ to 140℃ is achieved. • Ferroelectric relaxor temperature (T F-R) shifts towards room temperature with the addition of Sb 2 O 3. • The evolution from microdomain to nanodomain enhances strain response. [ABSTRACT FROM AUTHOR]

In this study, (1− x)Sr 0.49 Ca 0.21 Bi 0.2 TiO 3 - x Bi(Mg 0.5 Zr 0.5)O 3 ergodic relaxor ferroelectric ceramics were synthesized via a solid-state reaction method. The addition of Bi(Mg 0.5 Zr 0.5)O 3 expanded the temperature range for thermal activation of polar nanoregions (PNR s), resulting in high ergodicity of PNR s from 0 °C to 100 °C, leading to a broad dielectric constant plateau. Thus, the 0.95SCBT-0.05BMZ ceramic satisfied X9R requirements for capacitance temperature stability with a low temperature coefficient of 160 ppm/°C. The wide thermal activation temperature range also contributed to an increase in quantity rather than size of PNR s under applied electric field, thereby exhibiting diffuse phase transition (DPT) with high polarization response speed in SCBT-BMZ ceramics. Notably, the energy storage density of 2.81 J cm−3 was achieved by the 0.975SCBT-0.025BMZ relaxor ferroelectric ceramic under an electric field of 340 kV cm−1, demonstrating an efficiency of 89 %, a discharge energy density variation rate (from 0 °C to 100 °C) at only 9.7 %, and a transitory discharge time (t 0.9 ≈ 90 ns). • Lattice distortion expands the temperature range for thermal activation of PNR s. • DPT is attribute to the easy generation of PNR s under electric field. • High ergodic PNR s contributes to fast polarization response and transitory discharge time. [ABSTRACT FROM AUTHOR]

• Novel BNT-CZT multilayer ceramics are designed based on a multiscale synergistic manipulation strategy. • Ultrahigh W rec ∼ 13.4 J/cm3, giant W rec /E ∼160 J/(kV.m2) and high η ∼ 90.2 % are simultaneously achieved. • Superior energy storage stability over a broad tmperature range of 20–180 °C is also realized. • The underlying mechanisms for the substantially enhanced comprehensive ESP are visualized. Environmentally friendly dielectric ceramics with superior energy storage performances (ESP) are strongly demanded in pulsed power capacitor applications. Unfortunately, it is challenging to achieve simultaneously large recoverable energy density (W rec), high W rec / E (E as electric field) and broad operating temperature range in those ceramics. Herein we propose a multiscale synergistic regulation strategy to enhance comprehensive ESP of (Bi 0.5 Na 0.5)TiO 3 (BNT)-based ceramics. We introduce Ca(Zr 0.8 Ti 0.2)O 3 (CZT) into the BNT to increase atomic chaos and lattice distortion, which enhances relaxor behavior and lowers domain-switching barriers, thus effectively reducing remanent polarization. Besides, both suppressed oxygen vacancy and refined submicron grains improve extrinsic resistivity, which works synergistically with the enlarged intrinsic bandgap and multilayer structure design, producing substantially enhanced breakdown strength. Encouragingly, a very large W rec of 13.4 J/cm3, an ultrahigh W rec /E of 160 J/(kV∙m2), and a high efficiency η of 90.2 % are simultaneously achieved in the novel (Bi 0.5 Na 0.5)TiO 3 -Ca(Zr 0.8 Ti 0.2)O 3 (BNT-CZT) multilayer ceramics, together with outstanding energy storage stability over a broad working temperature range (20–180 °C). The comprehensive ESP of our multilayer ceramics are superior to most of previously reported lead-free ones. This work provides a feasible pathway for substantially improving comprehensive ESP of lead-free ceramics, and also highlights advanced energy storage potential of the BNT-CZT for high-performance pulsed power applications. [ABSTRACT FROM AUTHOR]

• A high energy density (W) value of 7.82 J/cm3 with energy storage efficiency (η) of 81.8% is acquired simultaneously. • A splendid thermal stability (Δ W rec : ∼ 2.9 %, Δ η : ∼ 3.9 %) within the temperature range of 20 ℃-100 ℃. • Further analysis of the influence of NaNbO 3 in KNN ceramics is investigated on the phase structure and microstructure. • Detailed discussions of evolution of domain structure and its influence on the energy storage properties after doping NaNbO 3. The advancement of high energy storage properties and outstanding temperature stability ceramics plays a decisive role in the field of pulsed power systems. The multi-component optimization strategy is conducted by introducing Li+, Bi(Ni 1/2 Zr 1/2)O 3 and NaNbO 3 into KNN-based ceramics. An excellent energy storage (W) of 7.82 J/cm3 along with a large efficiency (η) of 81.8 % is achieved at the breakdown strength (BDS) of 500 kV/cm for the ceramics. Simultaneously, the remarkable energy storage thermal stability (Δ W rec : ∼ 2.9 %, Δ η : ∼ 3.9 %) is acquired in the range from 20 ℃ to 100 ℃. The splendid charging-discharging performances (discharge energy density W d = 1.78 J/cm3, current density C D = 1376 A/cm2, power density P D = 124 MW/cm3) are also realized in the ceramics after doping. By investigating the evolution of crystal structure and domain structure, complex impedance and first-principle calculations, the internal mechanism of obtaining superior energy storage properties is analyzed. Thus, this research proves that the ceramics can effectively broaden the temperature range of the applications for the pulsed power systems while maintaining high energy storage properties, which offers a valuable approach for the improvement of dielectric capacitors. [ABSTRACT FROM AUTHOR]

Lead-free dielectric ceramics are crucial materials for the development of new electronic devices, displaying a wide range of operating temperatures, as well as corrosion resistance and high fatigue stability. However, the lower recoverable energy storage density (W rec) and efficiency (η) hinder their further development and application. It is crucial to simultaneously consider the high polarization strength and breakdown electric field for high-performance dielectric capacitors. Herein, we utilized a synergistic strategy that involves polarization delay and a multi-domain structure to synthesize the 1- x (0.85Bi 0.5 Na 0.5 TiO 3 -0.15NaNbO 3)- x SrHfO 3 ceramics (BNT- x SH). Eventually, the optimized BNT-0.10SH ceramic demonstrates outstanding energy storage performance, with a high recoverable energy density (W rec) of 3.04 J/cm3 and a good efficiency (η) of 76 % at 250 kV/cm. In addition, the BNT-0.10SH sample exhibits good temperature stability (68 °C–371 °C), frequency stability (50–300 Hz) and anti-fatigue stability (1–5 × 103 cycle). Furthermore, the BNT-0.10SH sample also attained a high current density (C D) of 1107 A/cm2 and a rapid discharge rate (t 0.9) of 91 ns. This work introduces a novel design concept and potential materials to meet the requirements of dielectric energy storage capacitors in complex conditions. • Delayed polarization and multi-domain structure are realized in BNT-based ceramics. • W rec of 3.04 J/cm3 at 250 kV/cm is obtained for BNT-0.10SH ceramics. • Outstanding C D of 1107 A/cm2 and fast discharge rate t 0.9 of 91 ns are achieved. [ABSTRACT FROM AUTHOR]

Relaxor ferroelectric materials with high piezoelectric properties always suffer from low phase transition temperature, making them difficult to satisfy the demands for high-temperature environment applications. In this work, we proposed a composite approach to improve the piezoelectricity and temperature stability of PSN-PMN-PT ceramics at the same time. The ZnO nanoparticles as a second phase were introduced into the PSN-PMN-PT matrix to form composite ceramics. When the ZnO content reaches 5 mol%, the piezoelectric constant d 33 increases from 529 pC/N for pure PSN-PMN-PT ceramic to 590 pC/N. Meanwhile, the retained d 33 after annealing at 200 °C keeps 92% of the value before annealing, indicating the thermal depolarization behavior is suppressed by the composite method. The synchronous improvement of the d 33 and thermal depolarization behavior for PSN-PMN-PT/ZnO composite ceramics is related to the local electric field and stress field caused by the addition of ZnO particles. Our results pave a simple and effective way to develop next-generation PT-based relaxor ferroelectric ceramics. [ABSTRACT FROM AUTHOR]

Dielectric capacitors show great potential in superior energy storage devices. However, the energy density of these capacitors is still inadequate to meet the requirement of energy storage applications. In this study, the Bi 0.5 Na 0.47 Li 0.03 TiO 3 - x NaNbO 3 (BNLT- x NN) ceramics were prepared via conventional solid-phase reaction. Results showed that NN can efficaciously enhance the breakdown strength (E b) and the relaxation behavior of the BNLT ceramic because of the broken ferroelectric long-range order. When x = 0.3, the maximum E b reached 350 kV/cm, at which the 0.7BNLT-0.3NN ceramic exhibited the high recoverable energy storage density (W rec) of 4.83 J/cm3 and great efficiency (η) of 78.9%. The ceramic demonstrated good temperature stability at 20 °C-160 °C and excellent fatigue resistance. Additionally, the 0.7BNLT-0.3NN ceramic presented high power density (P D ; ∼77.58 MW/cm3), large current density (C D ; ∼861.99 A/cm2), and quite short discharge time (t 0.9 ; ∼0.090 μs). These results indicated that the 0.7BNLT-0.3NN material has excellent energy storage properties and various application prospects. [ABSTRACT FROM AUTHOR]

The development of ferroelectric ceramics with both large piezoelectric responses and broad service temperature range is still a key challenge for practical applications due to the so-called d 33 - T C trade-off. Here we report the strategy to utilize the synergistic contribution of morphotropic phase boundary and enhanced local structural heterogeneity, in which an excellent piezoelectric coefficient d 33 of 680 pC/N and a high Curie temperature of 330 ℃ are simultaneously achieved in Sm modified 0.25PIN-0.325PZ-0.425PT ceramics. The underlying mechanism responsible for the high dielectric and piezoelectric properties is studied based on cryogenic dielectric measurement and Rayleigh analysis. Of particular interest is that, a high field-induced strain of 0.19% is achieved in 0.25PIN-0.32PZ-0.43PT at electric field of 20 kV/cm, corresponding to a piezoelectric d 33 * of 945 pm/V, showing an excellent temperature stability with minimal variation of 7% up to 310 °C. This work demonstrates the introduction of high temperature end members and rare earth doping are conducive to ferroelectric solid solutions with desired broad usage temperature range and superior piezoelectric properties, which will greatly benefit high temperature actuator applications. [ABSTRACT FROM AUTHOR]

Lead-free BNSTNZ ((Bi,Na,Ba,Sr)(Ti,Nb,Zr)O 3)-modified BF35BT (0.65BiFeO 3 -0.35BaTiO 3) dielectrics were investigated by conventional solid-state reaction method. Dielectric permittivity of BFBT-BNSTNZ ceramics was suppressed through addition of BNSTNZ content, while dielectric temperature stability range was expanded from 105 °C to 412 °C as BNSTNZ content increases from 0.025 to 0.1, due to the ferroelectric-relaxor phase transition. In particular, x = 0.10 exhibits the widest stability temperature range from 88 °C to 500 °C having small variation of (Δε m /ε m 150 °C ≤ 15%) with high dielectric permittivity (> 1000) and low dielectric loss (tanẟ ≤ 0.1) in temperature range from 50 °C to 250 °C. Moreover, high room temperature energy storage density (W store) of 0.75 and 0.57 J/cm3 with energy storage efficiency (ƞ) of 57% and 78% for x = 0. 03 and x = 0.10, respectively, was achieved. These results indicate that BFBT-BNSTNZ can be a promising system for high-temperature dielectric and energy storage applications. [ABSTRACT FROM AUTHOR]

BaTiO 3 -2 mol% MnYbO 3 -2 mol% CaZrO 3- x mol Nb 2 O 5 (x = 0, 0.3%, 0.5%, 0.7%) ceramics were successfully prepared via the conventional solid‐state method, followed by sintering in a reducing atmosphere. The effect of Nb 2 O 5 doping on the crystal structure, micromorphology and dielectric properties of sintered samples was studied, and the correlation mechanisms between the microstructure and dielectric properties were further determined. For x = 0.5 mol%, optimal dielectric properties with high permittivity (ԑ r ∼ 3570), low dielectric loss (tanδ ∼ 0.013) and large insulation resistivity (ρ v ∼ 4.95 × 1011 Ω cm) are obtained. On this basis, the temperature coefficient of the capacitance (ΔC/C 25°C) ranges between ±15% over the temperature range from −55 °C to 125 °C, satisfying the EIA X7R standard. Analysis shows that the increased permittivity of the doped ceramics at room temperature is due to enhanced short-range hoping polarization triggered by the formation of defect dipoles ( [ M n T i ″ − 2 N b T i · ] × and [ Y b T i ′ − N b T i · ] ×) and the release of oxygen vacancies. The high insulation resistivity is related to the grain size and electron migration in the ceramics. In addition, the improvement in the temperature stability of the ceramics is ascribed to a decrease in the Curie temperature. The polarization mechanism presented in this work can be extended to BaTiO 3 materials, and the results have important application value for BME-MLCC devices. [ABSTRACT FROM AUTHOR]

Grain-oriented Pb(Mg 1/3 Nb 2/3)O 3 -PbZrO 3 -PbTiO 3 (PMN-PZ-PT) based ceramics were synthesized through templated grain growth via using BaTiO 3 (BT) templates. Although BT templates are partially destroyed by PMN-PZ-PT matrix, CuO addition remarkably promotes [001] c -oriented grain growth behavior of the ceramics, resulting in an improvement of Lotgering factor F 001 from ~86% to 98%. Both crystallographic texture and CuO doping increase tetragonality and reduce average domain size of the ceramics dominated by rhombohedral phase. Consequently, 0.50 wt% CuO-doped ceramics (F 001 ~98%) exhibit optimum electromechanical properties: d 33 ~860 pC/N, d 33 × g 33 ~48.6 × 10−12 m2/N, k p ~0.80, E c ~7.2 kV/cm, tan δ ~0.8% and T c ~222 °C. In addition to ~3.7 times and 6.6 times higher d 33 and d 33 × g 33 , those ceramics possess about 240% enhanced piezoelectric strain and much better thermal stability (S max / E max variation ≤2% between RT and 150 °C) relative to non-textured counterpart. This work offers a good paradigm for simultaneously exploring high piezoelectric response and good temperature stability in piezoceramics, benefiting the development of next-generation advanced electromechanical devices. [ABSTRACT FROM AUTHOR]