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Dielectric ceramic capacitors with ultrahigh power densities are fundamental to modern electrical devices. Nonetheless, the poor energy density confined to the low breakdown strength is a long-standing bottleneck in developing desirable dielectric materials for practical applications. In this instance, we present a high-entropy tungsten bronze-type relaxor ferroelectric achieved through an equimolar-ratio element design, which realizes a giant recoverable energy density of 11.0 J·cm−3 and a high efficiency of 81.9%. Moreover, the atomic-scale microstructural study confirms that the excellent comprehensive energy storage performance is attributed to the increased atomic-scale compositional heterogeneity from high configuration entropy, which modulates the relaxor features as well as induces lattice distortion, resulting in reduced polarization hysteresis and enhanced breakdown endurance. This study provides evidence that developing high-entropy relaxor ferroelectric material via equimolar-ratio element design is an effective strategy for achieving ultrahigh energy storage characteristics. Our results also uncover the immense potential of tetragonal tungsten bronze-type materials for advanced energy storage applications. The authors present an equimolar-ratio element high-entropy strategy for designing high-performance dielectric ceramics and uncover the immense potential of tetragonal tungsten bronze-type materials for advanced energy storage applications. [ABSTRACT FROM AUTHOR]

High polarization of ferroelectric materials has profound research significance and is the decisive factor in the application of energy storage, pyroelectricity, and explosive energy conversion. Herein, in force-electric conversion field, an ultrahigh remanent polarization (51.43 μC/cm2) and record-breaking energy density (4.59 J/cm3) after poling were achieved with a lead-free (1 − x)Bi0.5Na0.5TiO3 − xAgNbO3 [(1 − x)BNT – xAN] relaxor ceramics. The enhancement effect of AgNbO3 on polarization is attributed to the increase in lattice distortion and orientation after poling. Additionally, a significant force-electric conversion effect under hydrostatic pressure (depolarization rate ∼44.8%, 400 MPa) and shock pressure (depolarization rate ∼54.4%, 6.3 GPa) in (1 − x)BNT – xAN was attributed to the pressure-driven ferroelectric/relaxor (FE/RE) phase transition. This work is expected to enlighten the further design of ferroelectric materials with high polarization for pulse power energy conversion application. [ABSTRACT FROM AUTHOR]

The most promising candidates for energy storage capacitor application are relaxor ferroelectrics, among which, the perovskite structure ferroelectric ceramics have witnessed great development progress. However, less attention has been paid on tetragonal tungsten bronze structure (TTBS) ceramics because of their lower breakdown strength and polarization. Herein, a multiscale regulation strategy is proposed to tune the energy storage performances (ESP) of TTBS ceramics from grain, domain, and macroscopic scale. The enhanced relaxor behavior with dynamic polar nanodomains guarantees low remanent polarization, while the refined grains and enlarged bandgap ensure increased breakdown strength. Hence, excellent ESP is realized in unfilled TTBS Sr0.425La0.1□0.05Ba0.425Nb1.4Ta0.6O6 (SLBNT) ceramics with an ultrahigh recoverable energy density of 5.895 J cm−3 and a high efficiency of 85.37%. This achievement notably surpasses previous studies in TTBS ceramics and is comparable to that of perovskite components. Meanwhile, the energy density exhibits a wide temperature, frequency, and cycling fatigue stability. In addition, high power density (257.89 MW cm−3), especially the ultrafast discharge time (t0.9 = 16.4 ns) are achieved. The multiscale regulation strategy unlocks the energy storage potential of TTBS ceramics and thus highlights TTBS ceramics as promising candidates for energy storage, like perovskite structured ceramics. [ABSTRACT FROM AUTHOR]

Bi0.5Na0.5TiO3‐based ceramics with high remnant polarization Pr have shown outstanding potential in the application of high‐power ferroelectric transducers. However, low depolarization temperature Td is an obstacle for their application. Here, a composition design strategy was proposed to simultaneously improve the Td and Pr in BNT‐based materials. Ultrahigh Pr of 40.56 µC/cm2 and relative high Td of 184°C were synergistically achieved in (Bi0.5Na0.5)(Ti0.995Mn0.005)O3 (BNMT) ceramics by adding 1.0 mol% BiGaO3 (BG), which is superior to other reported lead‐free systems. The excellent ferroelectric properties were attributed to strengthen ferroelectric order as evidenced by increased rhombohedral distortion. Meanwhile, the enhanced depolarization temperature, increasing from 168°C for x = 0% to 184°C for x = 1.0%, can be ascribed to the suppression of the thermal‐induced ferroelectric‐relaxor phase transition by adding BG. Those results enable the BNMT‐BG systems ceramics to be an attractive candidate for application in high‐power supplies. [ABSTRACT FROM AUTHOR]

(Pb, La)(Zr, Ti)O3 antiferroelectric (AFE) materials are promising materials due to their energy‐storage density higher than 10 J cm−3, but their low energy‐storage efficiency and poor temperature stability limit their application. In this paper, the (1 − x)(Pb0.9175La0.055)(Zr0.975Ti0.025)O3–xPb(Yb1/2Nb1/2)O3 (PLZTYN100x) AFE ceramics were prepared via two‐step sintering method and investigated thoroughly. With the doping of Yb3+ and Nb5+, the phase structure transforms from the orthorhombic phase (AFEO) to the coexistence of the orthorhombic‐and‐tetragonal phases. This structure reduces the free energy difference between the AFE and ferroelectric phases and reduces the fluctuation of energy with temperature, improving the energy storage efficiency and temperature stability. When the x = 0.05 (PLZTYN5), the AFE ceramic exhibits excellent temperature stability and ultrahigh energy storage performance, whose recoverable energy density (Wrec) is 6.8–8.2 J cm−3 at 30 kV mm−1 in the temperature range from −55 to 75°C, and efficiency (ƞ) is 78%–86.7%. In addition, the change of Wrec is less than 15%, exceeding the performance of most AFE ceramics. The results demonstrate that the PLZTYN5 ceramic has great potential in pulse power capacitors. [ABSTRACT FROM AUTHOR]

The energy storage performance of antiferroelectric ceramic capacitors has always gain much attention. Hysteresis, transition field, and polarization intensity are crucial factors influencing energy storage performance. A‐site doped small radius ions have been shown in numerous investigations to enhance the switching field, minimize hysteresis, but decrease maximum polarization intensity. How to maintain the high polarization while optimizing other parameters is a great challenge, and this problem has received scant attention in the research literature to date. In this work, Pb1‐xSrx(Zr0.54Sn0.46)0.975Nb0.02O3 (x = 0, 0.02, 0.06, 0.08, 0.1, 0.12, 0.14, 0.16, 0.20) antiferroelectric ceramics show high polarization stability. When the Sr2+ content is within 12 mol%, the saturation polarization intensity always remains at a large value (> 44μC/cm2), and the rate of change is as low as 6%. Pb0.92Sr0.08(Zr0.54Sn0.46)0.975Nb0.02O3 also displays great polarization temperature stability with a minimal change rate of 8.5% in a wide temperature range from ‐55 to 85°C. Additionally, this ceramic also has a superior energy storage performance that the recoverable energy density and energy storage efficiency and 8.95 J/cm3 and 80.4%, respectively. This work paves the way for practical simultaneous polarization and other parameter optimization. [ABSTRACT FROM AUTHOR]

This correction notice is for an article titled "High-entropy relaxor ferroelectric ceramics for ultrahigh energy storage" published in Nature Communications. The notice addresses two errors in the original article. The first error is in the first paragraph of page 4, where 'Tm,1MHz-Tm,10Hz' was incorrectly written. The correct version should state 'Tm,1MHz-Tm,10Hz'. The second error is in the first paragraph of page 7, where '(S1, S1)' was incorrectly written. The correct version should state '(Fig. S15)'. The correction has been made in both the PDF and HTML versions of the article. The authors of the article are Haonan Peng, Tiantian Wu, Zhen Liu, Zhengqian Fu, Dong Wang, Yanshuang Hao, Fangfang Xu, Genshui Wang, and Junhao Chu. [Extracted from the article]

The pressure‐driven force‐electric conversion materials with extremely rapid response time have been widely used in mining, defense, and energy areas. The discharge process by the force‐electric conversion effect in ferroelectrics is dominated by polar‐nonpolar phase transformation. In this work, (Pb0.985La0.01)(ZrxTi1‐x)O3 (PLZT, x = 0.85–0.94) ceramics is designed by tunning Zr4+/Ti4+ ratio and aliovalent La doping to achieve high remnant polarization (Pr) and excellent temperature stability. We focus on the pressure‐driven depolarization in PLZT ceramics, and their corresponding phase structure, ferroelectric properties, dielectric properties, and thermal depolarization. In PLZT (x = 0.93) ceramics, the original polarization P0 increases to 43.42 μC/cm2. The pressure‐driven depolarization releases 37.66 μC/cm2 with the depolarization proportion of 86.73%, which is attributed to irreversible ferroelectric‐antiferroelectric phase transition. It also exhibits excellent temperature stability up to 120°C (> 36 μC/cm2). This work provides a high‐performance alternative to Pb(Zr0.95Ti0.05)O3 and guidance for the development of pulse power energy conversion devices. [ABSTRACT FROM AUTHOR]

Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 ferroelectric ceramics with porous structure of periodic distribution were fabricated successfully via Direct Ink Writing, a type of 3D printing technique. The effect of periodically distributed porous microstructure on the dielectric, ferroelectric, as well as hydrostatic‐pressure‐induced depolarization properties of PZT95/5 ferroelectric ceramics, was investigated. The printed porous ceramics exhibit relatively good viscoelasticity to retain the periodic structure during 3D printing and drying. In contrast with dense PZT95/5 ferroelectric ceramics prepared by conventional solid‐state sintering, low bulk density of the periodically distributed porous PZT95/5 ceramics leads to a decreased remanent polarization of 22.9 µC/cm2 under 2 kV/mm. As the hydrostatic pressure increased, the poled periodically distributed porous PZT95/5 ceramics depolarize sharply under a low and narrow hydrostatic pressure range of 113–116 MPa with a released charge density of 23.9 µC/cm2, while the poled dense PZT95/5 ceramics depolarize under a range of 250–278 MPa. Therefore, the introduction of periodically distributed micropores into PZT95/5 ceramics decreases the ferroelectric‐to‐antiferroelectric phase transition hydrostatic pressure significantly and maintained relatively excellent other properties simultaneously, such as temperature stability and low dielectric loss. The almost sharp depolarization behavior under a significantly decreased hydrostatic pressure demonstrates that periodically distributed porous PZT95/5 ferroelectric ceramics fabricated controllably by 3D printing exhibit excellent performances and prospects in mechanical–electrical energy conversion applications. [ABSTRACT FROM AUTHOR]

As one of the classic antiferroelectrics, high complexity of a NaNbO3 structure sequence attracts great attention in the ferroelectric physics field. Here, temperature-pressure phase diagrams as a function of a CaSnO3 content for antiferroelectric (1-x)NaNbO3-xCaSnO3 ceramics have been improved by Raman spectroscopy. We clarify structural order of phase transitions on CaSnO3-modified NaNbO3 ceramics within the temperature range of 80–840 K by discussing the anomalies of lattice and phonon dynamics. The doping effect of CaSnO3 on the P-R phase transition has been summarized from the decreased critical temperature from 660 to 580 K. The intermediate phase at 480 K was recognized as an incommensurate phase. In addition, the anomalous pressure with respect to phonon frequency at the stress field of 0–25 GPa also provides the evidence of structural transformations at 6.55 and 10.05 GPa. Upon increasing the CaSnO3 content, phase transition moves to a lower pressure range. This work would provide the powerful supplement of phase transitions for the broad NaNbO3-based crystalline family with Raman scattering. [ABSTRACT FROM AUTHOR]

(Bi0.5Na0.5)TiO3 (BNT)‐based ferroelectric ceramics have drawn extensive attention because of their excellent electrical properties and interesting depolarization behavior. However, the poor thermal stability of electrical properties limits their practical application. In this work, the effect of sintering temperature (Ts) on the depolarization behavior of BNT‐based ceramics was systematically investigated. It is found that the depolarization temperature Td determined from pyroelectric measurement tends to decrease with increasing Ts, which indicates that lower Ts defers the ferroelectric‐relaxor (FE‐RE) phase transition. However, for the samples sintered at higher Ts (such as 1180°C), although the Td is reduced, the thermal stability is better compared with the sample sintered at lower Ts (1100°C) because the diffuse behavior of the FE‐RE phase transition is suppressed. According to these results, we propose that the thermal stability of electrical properties for BNT‐based ceramics is not only related to high Td, but also to the diffuse degree of phase transition. [ABSTRACT FROM AUTHOR]

Pulse power energy conversion materials with ultrafast discharge processes and ultrahigh power densities have been widely used in the defense, energy, medical, and mining fields. The pressure‐driven depolarization in ferroelectric materials is significant and accounts for the discharge processes. In this study, we focus on pressure‐induced depolarization in (Pb1‐1.5xLax)(Zr0.80Ti0.20)O3 (PLZT) (x = 0‐0.07) ceramics, and their corresponding phase structure, dielectric properties, ferroelectric properties, and thermal depolarization performances. Although a satisfactory pulse power energy conversion performance has been achieved in Pb(Zr0.95Ti0.05)O3 materials, poor temperature stability negatively influences their application. The static charge densities of PLZT (x = 0.04, 0.06) decreased from 29.11 μC/cm2 and 31.53 μC/cm2 to 19.76 μC/cm2 and 6.56 μC/cm2 under 400 MPa hydrostatic pressure, respectively, which is attributed to a pressure‐driven ferroelectric‐antiferroelectric phase structural transition. In particular, the temperature stability of PLZT (x = 0.06) materials is up to 87°C. This study may guide the further development pulse power energy conversion devices. [ABSTRACT FROM AUTHOR]

Ceramic‐based dielectric capacitor are highly suitable for pulsed power applications due to their high power density and excellent reliability. However, the ultrahigh applied electric field limit their applications in integrated electronic devices. In this work, (1−x){0.96(Bi0.5Na0.5)(Ti0.995Mn0.005)O3‐0.04BiAlO3}‐xNaNbO3 (BNT‐BA‐xNN, x = 0, 0.04, 0.08, 0.12, and 0.16) ternary ceramics were designed to achieve excellent energy storage properties. It was found that the introduction of NaNbO3 (NN) effectively increase the difference (ΔP) between Pmax and Pr, resulting in an obvious enhancement of the energy storage properties. High recoverable energy storage density, responsivity, and power density, that is, Wrec = 2.01 J/cm3, ξ = Wrec/E = 130.69 J/(kV⋅m2), and PD = 25.59 MW/cm3, accompanied with superior temperature stability were realized at x = 0.14 composition. In addition, the thermal stable dielectric properties of the sample can be prominently improved with increasing NN content. The temperature coefficient of capacitance (TCC) of x = 0.16 composition is lower than 15% over the temperature range from 49°C to 340°C, with a high dielectric permittivity of 1647 and a low dielectric loss (0.0107) at 150°C. All these features show that the BNT‐BA‐xNN ceramics are promising materials for energy storage application. [ABSTRACT FROM AUTHOR]

Ferroelectric materials under shock compression can generate current and power by a drastic change of the remnant polarizations and surface bound charge. This behavior has been employed in applications involving nuclear fusion trigger, energy storage devices, and high pulse power sources. Despite the large power output in lead‐containing ferroelectrics, lead‐free materials are highly desirable owing to the environmental concerns. Herein, the phase transition behaviors and current outputs of 0.92Bi0.5Na0.5TiO3‐0.08BiAlO3 (BNT‐8BA) materials are studied under high pressure. The BNT‐8BA ferroelectric ceramics can be completely depolarized from polar to the nonpolar state under shock compression, resulting in a current output in the external circuit. The phase‐transition‐induced depolarization pressures of BNT‐8BA are lower than those of the pure Bi0.5Na0.5TiO3 under both dynamic and static high‐pressure loads. These results can allow the understanding of the high‐pressure behavior of BNT‐8BA for application as ferroelectric pulsed power supply. [ABSTRACT FROM AUTHOR]

Dynamic temperature sensing and infrared detection/imaging near room temperature are critical in many applications including invasive safety alarming, energy conversion, and public health, in which ferroelectric (FE) materials play an extremely important role due to their pyroelectricity. As a result, over the past few decades many efforts have been made to improve the understanding of pyroelectrics, explore new pyroelectric materials, and promote their practical applications. In this review, we consider the pyroelectric parameters and the two pyroelectric operation modes. Then based on the operation modes, we review recent achievements in the FE ceramic materials for pyroelectric detection applications, including Pb(Zr,Ti)O3-based, (Bi,Na)TiO3-based, (Sr,Ba)NbO3-based, Pb(Sc,Ta)O3-based, (Ba,Sr)TiO3-based, and Pb(Zr,Sn,Ti)O3-based systems. This review will attempt to provide guidance for further improvements of the pyroelectric properties of these materials and consider future exploration of new FE and other material candidates for use in temperature and infrared sensing/detection applications. [ABSTRACT FROM AUTHOR]

Solid solutions of (1−x)PbZrO3‐xBa(Mg1/3Nb2/3)O3 (PZ‐xBMN, x = 0.02, 0.03, 0.04, and 0.05) were prepared, and their microstructures, electrical properties, and phase transition behaviors under hydrostatic pressure were investigated. It was found that the incorporation of BMN into PZ can provide improved ferroelectric properties, leading to the formation of antiferroelectric/ferroelectric phase boundaries in PZ‐xBMN ceramics when the value of x is between 0.02 and 0.03. It was also demonstrated that the ferroelectric phases exhibit excellent temperature stability in the remanent polarization. Importantly, complete depolarization was observed in the PZ‐xBMN solid solution due to the hydrostatic pressure‐induced ferroelectric‐antiferroelectric phase transition. The resultant properties and phase transition behaviors of PZ‐xBMN ceramics under pressure will benefit their application in pulsed power supplies. [ABSTRACT FROM AUTHOR]

Recently, dielectrics for energy storage have been attracting increasing attention due to their ultrahigh power density. However, the widespread application of dielectrics remains limited by their low energy density. In this work, lead-free single-phase relaxor (1 − x)Ba0.55Sr0.45TiO3-xBiMg2/3Nb1/3O3 [(1 − x)BST-xBMN] (x = 0, 0.05, 0.07, and 0.10) bulk ceramics were prepared by a conventional solid-state reaction process. The dielectric properties, the relaxor behavior, and the energy storage properties were explored in detail. With increasing BMN content, the observed increase in activation energy (Ea) and the decrease in freezing temperature (Tf) indicate that the coupling between polar nano-regions (PNRs) gradually weakened, leading to the decrease in remanent polarization (Pr) and the increase in energy storage efficiency (η). For the composition x = 0.07, the breakdown strength (BDS) significantly increased from 240 kV cm of pure BST to 450 kV cm. Finally, large Wrec (4.55 J cm3) and high η (81.8%) were achieved in 0.93BST-0.07BMN ceramics. The results demonstrate that the (1 − x)BST-xBMN ceramics have superior potential for use in advanced pulsed power capacitors. [ABSTRACT FROM AUTHOR]

Abstract: (1−x)Bi1/2Na1/2TiO3‐xPbMg1/3Nb2/3O3[(1−x)BNT‐xPMN] ceramics have been fabricated via a conventional solid‐state method for compositions x ≤ 0.3. The microstructure, phase structure, ferroelectric, and dielectric properties of ceramics were systematically studied as high‐temperature capacitor materials. XRD pattern certified perovskite phase with no secondary phase in all compositions. As PMN concentration increased, the phase of (1−x)BNT‐xPMN ceramics transformed from ferroelectric to relaxor gradually at room temperature, with prominent enhancement of dielectric temperature stability. For the composition x = 0.2, the temperature coefficient of capacitance (TCC) was <15% in a wide temperature range from 56 to 350°C with high relative permittivity (>3300) and low dielectric loss (<0.02) at 150°C, which indicated promising future for (1−x)BNT‐xPMN system as high‐temperature stable capacitor materials. [ABSTRACT FROM AUTHOR]

Abstract: The effect of lanthanum (La) content on the phase transformation of Pb1−3x/2Lax(Zr0.42Sn0.40Ti0.18)O3 (PLZST 100x/42/40/18, 0 ≤ x ≤ 0.06) ceramics was investigated by the dielectric and ferroelectric properties. The base composition PLZST 0/42/40/18 located in the ferroelectric (FE) rhombohedral phase region. As x increased, the compositions showed successively FE and antiferroelectric (AFE) state at room temperature, and their peak temperatures (Tmax) decreased gradually in line as Tmax = 162.21‐1507x. Evidence was presented that there were two dielectric anomalies in PLZST 2/42/40/18, which were corresponding to the FE‐AFE and AFE‐paraelectric (PE) phase transformations, respectively. With increasing the dc bias fields, the two phases merged into one. PLZST 3/42/40/18 showed AFE characteristics with the first loop outside of the second loop and there was only one dielectric inflection. The critical lanthanum content occurred at x = 0.03 from the dielectric temperature spectra and hysteresis loops. Furthermore increase in La above 0.03, these compositions showed typical antiferroelectric behaviors with double hysteresis loops. The stored energy properties of the three compositions (PLZST 4/42/40/18, 5/42/40/18 and 6/42/40/18) displayed different temperature dependencies from room temperature to 140°C (over their respective Tmax). Comparing the above results with previous investigations on PLZSTs, some questions were discussed. [ABSTRACT FROM AUTHOR]

The pulsed power supply that generates megawatts of electrical power has drawn important attention for many decades. Despite that the large energy output has been obtained in lead-containing materials such as Pb(Zr0.95Ti0.05)O3 (PZT95/5) ceramics, lead-free ferroelectric candidates are highly desired due to the environmental concerns. In this work, we report the depolarization behavior of lead-free ternary 0.99[0.98(Bi0.5Na0.5)(Ti0.995Mn0.005)O3-0.02BiAlO3]-0.01NaNbO3 ferroelectric ceramics under shock wave compression. A current profile with a maximum value of ∼25 A and a FWHM of ∼2.3 μs was obtained. Particularly, the poled BNT-BA-0.01NN ceramics were almost completely depolarized under high strain rate loading, releasing a high charge density J of 38 μC/cm2. The released J was approximately 96% of thermal-induced charge density (∼40 μC/cm2), which was 18% higher than that of PZT95/5 ceramics. The shock-induced depolarization mechanism can be attributed to the ferroelectric-ergodic relaxor phase transition. These results reveal the BNT-based ceramics as promising candidates for pulsed power applications. [ABSTRACT FROM AUTHOR]

Microstructure, phase transition and electric properties of Pb 0.99 (Zr 0.95 Ti 0.05 ) 0.98 Nb 0.02 O 3 (PZTN 95/5) ferroelectric ceramics modified with x wt% ZnO additive (where x  = 0, 0.1, 0.2, 0.3 and 0.4) were systematically investigated. It was found that ZnO modification brought out an improvement of densification and an increase in grain size of PZTN 95/5 ceramics. Results of dielectric and pyroelectric measurements demonstrated that, the low temperature rhombohedral-high temperature rhombohedral ferroelectric phase transition temperature ( T LH ) gradually decreased with increasing x to 0.2, while the Curie temperature ( T c) gradually increased. With further increasing ZnO content, however, T LH and T C almost showed no change. Additionally, the excellent ferroelectric, pyroelectric and piezoelectric properties were all achieved by less than 0.2 wt% ZnO modification. It is suggested that, due to superior room–temperature pyroelectric properties, the 0.2 wt% ZnO-modified PZTN 95/5 ceramics may be a promising material for applications in uncooled pyroelectric infrared detectors. [ABSTRACT FROM AUTHOR]

In this paper, the influence of phase evolution on polarization change and electrocaloric response in lead-free (Ba0.9Ca0.1)(Ti1− x Zr x)O3 ceramics ( BCTZ) was systematically investigated. With increasing Zr/Ti ratio, the phase structure and phase transition behavior were greatly changed, resulting in various temperature and electric field dependence of electrocaloric responses. For x=0.05, a peak electrocaloric temperature change 1.64 K (at 130°C) and corresponding entropy change 1.78 J·kg−1·K−1 were obtained for 0-7 kV·mm−1 electric field. Negative electrocaloric temperature change in −0.1 K was obtained below Curie temperature ( Tc), which may be induced by the orthorhombic-tetragonal ferroelectric phase transition. With the increase in x, the peak value of the electrocaloric response decreased but much better temperature stability was observed. Simultaneously the negative electrocaloric response gradually disappeared with the disappearance of the low temperature ferroelectric-ferroelectric phase transition. For x=0.2, electrocaloric response showed good temperature stability ranging from room temperature to 130°C, attributing to the relaxor ferroelectric feature. [ABSTRACT FROM AUTHOR]

PZT95/5 ferroelectric ceramics are widely utilized in pulsed power devices and the remanent polarization Pr of poled PZT95/5 can characterize the shock-driven energy density. However, this remanent polarization is difficult to be measured nondestructively. In this article, a series of pyroelectric tests of poled PZT95/5 ceramics were conducted near room temperature, from 25°C to 20°C. A linear relation between Pr and pyroelectric coefficient p was found, that is, Pr=1190.5( K)× p, which provides an effective way to nondestructively estimate the value of Pr of the poled PZT95/5 ceramics by measuring the pyroelectric coefficient p at room temperature. According to Devonshire's phenomenological theory, this result could be explained by a modified equation: [ABSTRACT FROM AUTHOR]

(Bi0.5Na0.5)TiO3-BiAlO3 lead-free materials exhibit excellent ferroelectric properties, but its depolarization temperature is relatively low which is the major obstacle limiting the material's practical application. In this study, the effects of Manganese (Mn) modification on the microstructure, ferroelectric properties and depolarization behavior of 0.96(Bi0.5Na0.5)(Ti1− xMn x)O3-0.04BiAlO3 ceramics were investigated. It was found that the average grain size was enlarged and ferroelectric properties were enhanced with small Mn addition, meanwhile the tangent loss decreased. The remnant polarization ( Pr) of the samples reached an optimal value (~41 μC/cm2) as Mn content increased up to 0.7 mol%, whereas further addition resulted in the decrease in Pr. Moreover, appropriate Mn addition ( x=0.7%) can improve the depolarization temperature from 140°C to 161°C determined from thermally stimulated depolarization currents measurement. [ABSTRACT FROM AUTHOR]

The Al 2 O 3 -modified Pb 0.99 (Zr 0.95 Ti 0.05 ) 0.98 Nb 0.02 O 3 (PZT 95/5) ferroelectric ceramics with enhanced breakdown strength were prepared from PZT 95/5 powders coated with a thin Al 2 O 3 shell layer, which were fabricated by a Citrate-Chelation method followed by a conventional sintering process. The microstructure and electrical properties of the as-prepared ceramics as a function of Al 2 O 3 content were systematically investigated. The results reveal that Al 2 O 3 nanoparticles are successfully coated on PZT 95/5 powders to form the core–shell structure and well dispersed at the grain boundaries of the PZT 95/5 ceramic matrix after sintering, which strengthened the grain boundaries. In particular, compared with pure PZT 95/5 ferroelectric ceramics, PZT 95/5 ceramics with less than 1.0 wt% Al 2 O 3 inclusion possess the enhanced breakdown strength and energy density, of which the largest increment being 25.9% and 13.5%, respectively. It is indicated that the as-prepared PZT 95/5 ferroelectric ceramics may be a promising candidate for explosively driven power supply. [ABSTRACT FROM AUTHOR]

Pb(ZrTi)NbO (PZTN 95/5) ferroelectric ceramics were fabricated using low-temperature sintering process with the addition of CuO as sintering aid. The influence of CuO on the microstructure, breakdown strength and energy density of PZTN 95/5 ceramics were investigated. The results of the relative density and the grain size distribution show that, compared with pure PZTN 95/5 ceramics, 0.2 wt% CuO-added PZTN 95/5 ceramics show a higher density and smaller and more uniform grains. More importantly, an improved dielectric breakdown strength by 15.5 % is achieved in 0.2 wt% CuO-added samples, due to the increase of the density and the decrease of the grain size. Then, an enhanced energy density is also obtained. It is suggested that the preparation of PZTN 95/5 ferroelectric ceramics with high density and fine grains by the addition of CuO provides a promising method to improve the reliability and power output density of pulse power supplies. [ABSTRACT FROM AUTHOR]

The phase transition behaviors of Pb 0.99 (Zr 0.95 Ti 0.05 ) 0.98 Nb 0.02 O 3 ferroelectric ceramics doped with different MgO concentrations (0–0.2 wt%) were systematically investigated by Raman and dielectric measurements. Raman results showed that the phase transitions were strongly dependent on MgO concentration. It was found that the low temperature rhombohedral (F R(LT) )–high temperature rhombohedral (F R(HT) ) ferroelectric phase transition shifted toward a lower temperature with increasing MgO concentration up to 0.1 wt%, while the F R(HT) –cubic paraelectric (P C ) phase transition changed to a higher temperature. The Raman results were in good agreement with phase transition determined by dielectric measurements. Moreover, it was indicated that the changes of Raman active modes were related to distortion of BO 6 octahedra during the phase transitions. Then, the distortion of BO 6 octahedron caused by B-site replacement of Mg 2+ ions was proposed to explain the observed behaviors. In addition, the effects of MgO doping on the dielectric, ferroelectric and pyroelectric properties were also discussed. [ABSTRACT FROM AUTHOR]

Dynamic hysteresis of Nb-doped Pb( Zr1− x Ti x) O3 ( PZT, 0.20 ≤ x ≤ 0.60) ceramics were studied systemically at different field ( E) and frequency ( f). The hysteresis loops were strongly dependent on E and f. The measured coercive fields ( Ec0) were far lower than the calculated values based on the Landau-Ginzburg theory, and increased dramatically from the rhombohedral phase to the tetragonal phase while had less variation with composition in the same phase. With increasing E or f for each composition, three types of loops were observed: linear, minor, and saturated loops. The cross fields ( E0), cross polarizations ( P0), and hysteresis areas ( ) showed different variation regularities with f. Similar varying curves were observed for all PZT ceramic samples by normalizing E0, P0, and with E/Ec0, which indicated the same polarization switching for different domain structures. Further analyses revealed that the switching processes can be divided into three stages: space charge polarization, domain switching, and steady state. The first and second stage occurred at ~0.5 and ~1.5 E/ Ec0, respectively. These results would be very helpful to further understand the polarization switching of ferroelectric ceramics. [ABSTRACT FROM AUTHOR]

The low-temperature sintering and electric properties of Pb0.99( Zr0.95 Ti0.05)0.98 Nb0.02 O3 ( PZTN 95/5) ferroelectric ceramics with CuO addition was investigated. The CuO addition significantly promoted the densification and reduced the sintering temperature of PZTN 95/5 ceramics by more than 200°C. The 0.2 wt% CuO-added sample sintered at 1150°C exhibited the optimum relative density of 96.7% and excellent electric properties with values of Pr = 37.80 μC/cm2, TC = 223°C, εr = 329, and tan δ = 0.016, which were superior to that of PZTN 95/5 ceramics sintered at 1350°C. [ABSTRACT FROM AUTHOR]

Abstract: Sr x Ba1−x Nb2O6 (with x=0.50, 0.45, 0.40 and 0.30) ceramics were synthesized by conventional solid-state method and sintered at 1350°C for 3h. The phase structure, microstructure, dielectric, ferroelectric and pyroelectric properties of obtained ceramics were systematically investigated. Pure tungsten bronze phase could be obtained in all ceramics. The dielectric characteristics showed that SBN ceramic was a relaxor with strong diffuse phase transition and weak frequency dispersion. As Sr molar fraction x increases from 0.30 to 0.50, the transition temperature T C decreased linearly while the diffusivity parameter γ declined from 1.88 to 1.68. The saturated polarization, remnant polarization and pyroelectric coefficient were also found to be enhanced in SBN ceramics with increasing Sr content. The pyroelectric coefficient of about 2×10−8 C/cm2K can be obtained for polarized SBN50 ceramics at room temperature. [Copyright &y& Elsevier]

The ferroelectric domain plays an important role in determining the piezoelectric performance of ferroelectric ceramics. Herein, LiNbO 3 (LN) is used as an additive to tune the ferroelectric domain of 0.49Pb(Ni 1/3 Nb 2/3)O 3 -0.2Pb(In 1/2 Nb 1/2)O 3 -0.31PbTiO 3 (PNN-PIN-PT) ceramics. PNN-PIN-PT-0LN ceramic exhibits the ordered tetragonal phase (90 °) domain wall and rhombohedral phase (71 ° and 109 °) domain wall. Incorporating LN into the system leads to the transformation of the majority of structured macro-domains into random micro-domains with smaller sizes, which disrupt their long-range ordered ferroelectric domains, resulting in significant piezoelectric enhancement. Compared to PNN-PIN-PT-0LN ceramics, PNN-PIN-PT-1.8LN ceramics exhibit giant piezoelectric responses with d 33 = 1112 pC/N, d 31 =521 pC/N, d 33 * =1220 pm/V (@ E = 5 kV/cm), ε r = 12092. These findings shed light on a specific aspect of domain engineering in piezoelectric materials, thus contributing to a more comprehensive understanding of the underlying factors that give rise to the phenomenon of giant piezoelectricity. [ABSTRACT FROM AUTHOR]

Due to the high demand for dielectric materials with high energy density, the energy storage performance of antiferroelectric ceramic capacitors has always gained much attention. Polarization intensity is a key factor that is closely related to the energy storage density. However, thus far, there has been a lack of research studies or successful methods to effectively modulate polarization intensity. The behavior of the polarization process is complex and contains domain nucleation, growth, and flip-flapping. Based on this finding, the introduction of Nb5+ at the B-site was designed to influence the three stages of antiferroelectric polarization by regulating the balance between the ferroelectric and antiferroelectric phases, and eventually realized regulation of the saturation polarization intensity in the (Pb 1-1.5x La x)(Zr 0.5 Sn 0.43 Ti 0.07)O 3 antiferroelectric ceramics. The saturation polarization intensity has increased from 25.56 to 42 μC/cm2 with Nb5+ content increases from 0 to 4 mol% and the hysteresis was kept low, Pb 0.94 La 0.04 (Zr 0.65 Sn 0.35) 0.975 Nb 0.02 O 3 is the optimal component with a high releasable energy density of 8.26 J/cm3 and an energy storage efficiency of 90.31%. This work provides an in-depth explanation of the microscopic mechanism of antiferroelectric ceramic polarization and presents a novel approach for the composition design of high-energy storage density antiferroelectric ceramics. [ABSTRACT FROM AUTHOR]

Cax(Sr0.5Ba0.5)1-xNb2O6 [CSBN(x), x = 0.00, 0.10, 0.15, and 0.20] lead-Free ceramics were prepared by a traditional solid-state reaction technique. Dielectric, ferroelectric, and pyroelectric properties of CSBN(x) lead-Free ceramics were systematically investigated. The pyroelectric properties of CSBN(x) have been enhanced remarkably due to Ca addition and reached the maximum values at x = 0.15, with pyroelectric coefficient of 3.61 × 10-8 C/cm2 K and pyroelectric figure of merit of Fi = 172 pm/V, Fv = 0.021 m2/C, and Fd = 11.5 μPa-1/2, which are superior to other lead-free ferroelectric ceramics. These results indicate the potential of CSBN(x) ceramics for infrared detector applications. [ABSTRACT FROM AUTHOR]

• Achieving ultrahigh W rec of 10.0 J/cm3 and η of 91 % in BST-based ceramics. • The variation of relaxor feature is analyzed by multi-polarization mechanism model. • Simultaneously toughening and enhanced energy storage performance are realized. Lead-free ceramic capacitors offer ultrahigh power density and ultrafast discharging rates, making them critical energy storage components for advanced pulsed power systems. However, the greatest obstacle to broader applications remains the relatively low energy storage density. In this study, a relaxor ferroelectric ceramic based on (0.6-x)Ba 0.55 Sr 0.45 TiO 3 -0.4Bi 0.5 Na 0.5 TiO 3 -xSrZrO 3 ((0.6-x)BST-0.4BNT-xSZ) is prepared using the tape casting method, resulting in an excellent energy density (W rec ≈ 10.0 J cm−3) and high energy storage efficiency (η ≈ 91 %). The solid solution of linear dielectrics SrZrO 3 synergistically regulates both relaxor properties and breakdown strength. The variation of relaxor property was explored utilizing New Glass model and the multi-polarization model, with confirmation provided by piezoresponse force microscopy. Furthermore, the breakdown strength could be attributed to improvements in electric insulation and the widening of the bandgap. As SrZrO 3 content increases, the in-situ emergence of the second phase ZrO 2 , accompanied by a martensitic transformation, not only improves the fracture toughness of ceramics but also serves to elongate the breakdown path. Encouragingly, x = 0.20 ceramics also achieve excellent temperature stability (−95–125 ℃), frequency stability (1–1000 Hz), cycling reliability (1–106 cycles), and great charging-discharging properties. This multiscale synergic regulation strategy plays a guiding role in the screening of high-performance energy storage dielectric materials. [ABSTRACT FROM AUTHOR]

Pulse ceramic capacitors that request particularly high reliability and long lifetime forbid over-applied electric field, hence demanding high energy density (W re) and energy storage efficiency (η) at low electric field. In this work, we investigated a lead lanthanum zirconate titanate (PLZT) ceramic featuring both of tetragonal antiferroelectric phase (AFE T) and relaxor characteristic, which emerge in converged area of PLZT phase diagram (mole ratio of La reaches ~10%). Temperature dependent permittivity and XRD analysis proves the crossover trait in this structure. In this special relaxor-like AFE T structure, decent W re (1.2–1.3 J cm−3) and η (86–90%) are achieved at 12 V μ m−1. Equivalent dielectric constant (ε eq) is also introduced to illustrate nonlinear energy storage performance at different electric field. Compared to common dielectric materials, tunable ε eq in relaxor-like AFE T structure shows advantages of excellent low-field energy density and wide working span, leading to the convenience in size design of capacitors. Finally, good energy storage stability under various external field was verified: ~1.00 J cm−3 in W re and ~92% in η were stabilized under varied frequency (< ± 8.9%, 0.01–2000 Hz), temperature (< ± 9.8%, −60 to 120 ℃) and fatigue loading (< ± 9.8%, >108 times) at ~10 V μ m−1. [ABSTRACT FROM AUTHOR]

Barium Strontium Titanate (Ba 1-x Sr x TiO 3 , BST) possesses the advantages of high permittivity, low remnant polarization and dielectric loss, suggesting great potential in the application of power capacitors. However, the low maximum polarization severely restricts the achievement of outstanding energy storage properties (ESP). Herein, we design a lead-free bulk ceramic: (1-x)Ba 0. 55 Sr 0 · 45 TiO 3 -xBi 0.5 Na 0. 5 TiO 3 [(1-x)BST-xBNT] (x = 0.1–0.4), prepared by two-step solid-state reaction method. The introduction of BNT contributes to (1) the boost of maximum polarization (from 21 μC/cm2 up to 32.6 μC/cm2) due to Bi3+ lone pair covalent effect (2) strong relaxor behavior (1.71≪ γ 1.84) derived from weakly coupled nanopolar regions, which can be verified by high activation energy E a = 0.341 eV at x = 0.3, improves the ESP and thermal stability of the ceramics. According to the above strategies, high W rec = 1.73 J/cm3 and η = 84.4% are achieved in the 0.7BST-0.3BNT ceramics at 206 kV/cm, which is preferable to the previous results regarding BST-based bulk ceramics. The excellent thermal stability (20–120 °C), frequency stability (1–500 Hz), as well as anti-fatigue characteristic (cycling number: 105) were obtained in the 0.7BST-0.3BNT. Furthermore, 0.7BST-0.3BNT ceramics exhibit high-power density (P D = 44.9 MW/cm3) and rapid discharge rate (t 0.9 = 99.2 ns) from 20 °C to 120 °C. This work provides a feasible way to achieve good energy storage and charge-discharge properties for pulse power energy storage systems. [ABSTRACT FROM AUTHOR]

(Pb, La)(Zr, Sn, Ti)O 3 (PLZST) ceramic is one of the most prospective antiferroelectric (AFE) materials for variety of functional applications including energy storage and converter. Systematic structural investigation of domain structures should be of fundamental importance for understanding the structure-property relationship in AFE ceramics. In this study, the hierarchical domain structures and modulated structures correlated to the compositional variation in (Pb 0.97 La 0.02) (Zr 0.50 Sn x Ti 0.50-x)O 3 (x = 0.375, 0.45 and 0.50) were observed and investigated in details by transmission electron microscopy. The PLZST ceramics show exclusively incommensurate modulated structures (IMS) whose modulation period changed from 9.37 to 6.15 and to 4.04 with increasing of the x value. The hierarchical domain structures include, in decreasing scales, AFE domains, incommensurate domains and nanodomains. The elementary domains in PLZST ceramics are pinstriped nanodomains which were formed based on IMS configuration but by frequent modulation of IMS periodicity and formation of faults. Nanodomains accumulated and then dissociated into incommensurate domains and AFE domains successively. The presently revealed structural characteristics in antiferroelectric PLZST may stimulate future researches on the evolution of IMS-based hierarchical domains under external physical fields, e.g. thermal or electrical, and their correlation to the physical performance. [ABSTRACT FROM AUTHOR]

The grinding strain induced ferroelectric (FE) to antiferroelectric (AFE) phase transition with associated hysteresis loops tuning were found in bulk Pb 0.99 (Zr 0.97 Ti 0.03) 0.98 Nb 0.02 O 3 ceramics. The induced AFE phases can keep stable unless applying heat treatment or electric field. The atomic-scale characterizations reveal that the perfect coherent FE/AFE interface appears either diffuse or sharp depending on its relative orientation to polarization. The induced surface AFE layers on FE bulk can tune hysteresis loops from symmetric to asymmetric and this effect increased with the decrease of thickness of samples. These findings provide new pathway for manipulate phase state and discover novel properties in ferroics. Grinding strain induced ferroelectric-antiferroelectric phase transition with hysteresis loops tuning in bulk ceramics. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• a way of external pressure to enhance energy storage properties of AgNbO 3 ceramics. • An η of 56% and W rec of 1.3 J/cm3 has been achieved in AgNbO 3 ceramics under 400 MPa. • Hydrostatic pressure results in an enhancement in η and W rec by 47% and 23%, respectively. Despite its low energy storage efficiency (∼46%), silver niobate (AgNbO 3) is considered as a promising lead-free antiferroelectric material due to its environmental advantages. Herein, we demonstrate that the energy storage efficiency of AgNbO 3 ceramics can be enhanced by applying hydrostatic pressure. The results reveal that the hydrostatic pressure contributed to the decline of remanent polarization (P r) and the switching hysteresis Δ E. In addition, the externally applied pressure improved the reverse switching field (E A). This indicates an enhanced antiferroelectricity, benefiting the enhancement of energy storage properties of AgNbO 3 ceramics. Under the pressure of 400 MPa, the as-prepared AgNbO 3 ceramics exhibited an energy storage efficiency (η) of 56% and a recoverable energy storage density (W rec) of 1.3 J/cm3 under the electric field of 13 kV/mm, corresponding to an enhancement of 47% and 30%, respectively. [ABSTRACT FROM AUTHOR]

Highlights • Temperature-dependent optical ellipsometry measurements have been performed. • The SCP model was used to analyze the complex dielectric function. • Phase transitions were clarified with the variation of CP energies. Abstract The dielectric functions and phase transitions of MgO modified Pb 0.99 (Zr 0.95 Ti 0.05) 0.98 Nb 0.02 O 3 (PZTN- x wt% MgO, x = 0, 0.1, 0.2, 0.5) ceramics have been investigated using temperature-dependent spectroscopic ellipsometry. With the aid of standard critical-point (SCP) model, four typical interband transitions can be observed from the second derivative of dielectric functions. Three transition process are observed and can be linked to antiferroelectric (AFE)-ferroelectric (FE) (T 1 ∼ 250 K), low temperature ferroelectric phase [FE R(LT) ]to high temperature one [FE R(HT) ] (T 2 ∼ 300 K), and ferroelectric-paraelectric phase (T C ∼ 500 K). [ABSTRACT FROM AUTHOR]

• The composite ceramics Bi 0.5 Na 0.5 TiO 3 -Sm 2 Ti 2 O 7 were successfully prepared. • Excellent electrical properties and stability are obtained in BNT-STO ceramics. • A new effective method to design high ESP ceramic materials is proposed. The comprehensive performance of ferroelectric ceramic materials is a significant factor limiting the practical application. In this work, a novel strategy of constructing diphase compounds is proposed to significantly enhance the energy storage properties of Bi 0.5 Na 0.5 TiO 3 -based ceramics. A composite ceramic of pyrochlore phase Sm 2 Ti 2 O 7 modified perovskite phase Bi 0.5 Na 0.5 TiO 3 is successfully prepared and systematically studied. As the concentration of Sm 2 Ti 2 O 7 increases, the dielectric breakdown strength is greatly strengthened because of expanded band gap and shrunk grain size, and the relaxor behavior is enhanced due to the effect of linear character pyrochlore. As a result, the optimized composition demonstrates excellent energy storage properties including high recoverable energy storage density (W rec) of 6.387 J/cm3 at 402 kV/cm, superior stability of temperature (<6% variation in − 120 ∼ 120 °C), frequency (∼4% variation in 5 ∼ 500 Hz) and cycling (∼2% variation within 106 cycles). Besides, fast discharge behavior of t 0.9 ∼ 29.4 ns and high power density of 80.49 MW/cm3 at 200 kV/cm are also achieved. This study presents a novel strategy to enhance the performance of BNT-based materials through forming composite ceramic, which is anticipated to be a general method for other material systems as regards the design of advanced energy storage ceramics. [ABSTRACT FROM AUTHOR]

A comparative experimental study of shock compressed Pb 0.99 (Zr 0.95 Ti 0.05 ) 0.98 Nb 0.02 O 3 (hereafter referred to as PZT95/5) ferroelectric ceramics within different insulation materials were performed in this study. It was found that the insulating materials play a significant role in the electrical failure behavior of PZT95/5 ferroelectric ceramic. The electrical breakdown behavior of PZT95/5 ferroelectric ceramics within epoxy resin was observed to aggravate at low temperature −55 °C. Porous PZT95/5 ferroelectric ceramic was found to exhibit lower failure probability than its dense counterpart. Electrical failure of PZT95/5 ferroelectric ceramics under shock wave was found to be an extrinsic behavior and a tentative explanation was proposed based on the mechanical compressive stress-induced cracks initiation by epoxy resin. [ABSTRACT FROM AUTHOR]

The dynamics of domain switching of Bi 0.5 Na 0.5 TiO 3 -based ferroelectric ceramic was investigated. With the electric field increasing, the domain switch experienced three sections of no domain switch region, creep region and flow region. In the creep region, the domain switch is dominated by the thermally activated domain wall movement. In flow region, the domain wall experience the viscous flow motion. For the BNT-BA-Zn ceramic, the activation energy of creep domain switch is much higher than it in flow region. With temperature increasing, the sensitivity of domain wall motion to the frequency is decreasing. This result demonstrated the domain switch of different ferroelectric materials could be quantitatively analyzed and compared based on the simple polarization - current - electric field data. [ABSTRACT FROM AUTHOR]

Reversible domain switching in aged acceptor-doped ferroelectric ceramics is a powerful method to achieve electrostrain due to the exchange of nonequal crystalline axes of domains. Nevertheless, previous work suggested that the strain obtained via reversible domain switching in unpoled ceramics was much lower than theoretical value. In this paper, we demonstrate that the strain in poled and aged acceptor-doped ferroelectric ceramics can be significantly enhanced when the driving electric field is perpendicular to the poling direction, originating from the exchange of nonequel crystalline axes of more domains. Consequently, the electrostrain of poled and aged 0.1 wt% MnO 2 -doped 0.05Pb(Mn 1/3 Sb 2/3 )O 3 −0.50PbZrO 3 −0.45PbTiO 3 could reach 0.225% which was 4.17 times larger than that of unpoled sample under a low electric field of 15 kV cm −1 . Moreover, the corresponding normalized strain d 33 * reached 1500 pm V −1 which significantly exceeded the values reported in ferroelectric ceramics. Our work provide a general effective method to enhance the electrostrain behavior via reversible domain switching in aged acceptor-doped ferroelectric ceramics. [ABSTRACT FROM AUTHOR]

Highlights: [•] Sandwich-like structure Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 ferroelectric ceramics were designed and prepared. [•] The new structure exhibits the high ferroelectric properties, typical of dense PZT95/5 ferroelectric ceramics. [•] The new structure also exhibits high voltage breakdown resistance of porous PZT95/5 ferroelectric ceramics under shock compression. [•] The enhanced performances make the new structure promising candidate for pulsed power supply application. [ABSTRACT FROM AUTHOR]

Highlights: [•] Remarkable microstructural evolution was observed in different Sm2O3 doping levels. [•] The electrical properties can be tailored in a wide range. [•] The fracture toughness is enhanced, comparative to the dense PZT ceramics. [ABSTRACT FROM AUTHOR]