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Achieving comprehensive improvement in both piezoelectric coefficient (d33) and mechanical quality factor (Qm) has become a key issue in the research of high‐power piezoelectric ceramics. Here, we focused on Mn‐doped Pb(In1/2Nb1/2)O3‐Pb(Sc1/2Nb1/2)O3‐PbTiO3 (PIN‐PSN‐PT) relaxor ferroelectric ceramics, where Mn‐doping is employed to enhance Qm. The effects of doping concentration and PT content on phase structure, ferroelectric, dielectric, and electromechanical properties were systematically studied. The well radius matching between Mn ions and B‐site ions facilitates the ion substitution and significantly increases the concentration of oxygen vacancies, thereby enhancing the domain wall pinning effect. A significantly weakened mutual constraint relationship between d33 and Qm is observed in the 2 mol% Mn‐doped PIN‐PSN‐PT ceramics with tetragonal phase, which exhibits Qm exceeding 3000 while maintaining d33 higher than 320 pC/N and Curie temperature higher than 300°C, leading to the vibration velocity over 1.15 m/s. Rayleigh analysis reveals the higher intrinsic piezoelectric response in high PT components compared to that in low PT components, which was thought to be the origin for the weakened mutual constraint relationship between d33 and Qm in tetragonal Mn‐doped PIN‐PSN‐PT ceramics. [ABSTRACT FROM AUTHOR]

Textured relaxor-PbTiO3 ceramics have received considerable attention from both academia and industry, due to their crystal-like properties, high composition homogeneity easy-to-process, and relatively low cost compared to their crystal counterparts. In this work, the ⟨ 001 ⟩ -oriented Pb(In1/2Nb1/2)O3-Pb(Sc1/2Nb1/2)O3-PbTiO3 textured ceramics were fabricated by the template grain growth method. To explore the property variation in these textured ceramics under practical applications of piezoelectric devices, their electromechanical properties were characterized and analyzed under uniaxial stress, hydrostatic pressure, and d.c. bias electric field. The results show that the dielectric constants of all textured ceramics increase with an increase in the uniaxial prestress and hydrostatic pressure but decrease with an increase in the d.c. bias electric field. Among all textured ceramics, the textured ceramic with 3 vol. % BT templates exhibits the best stability under external fields. In particular, the electromechanical coupling factors of the textured ceramic change less than 2% with the hydrostatic pressure increase to 100 MPa. This work provides important data on textured relaxor ferroelectric ceramics, which will benefit the design and application of piezoelectric devices based on textured piezoelectric ceramics. [ABSTRACT FROM AUTHOR]

As one of the important electronic components, the dielectric capacitors for energy storage applications have been extensively studied in recent years. Among various dielectric materials, the perovskite oxide Bi0.5Na0.5TiO3‐based ceramics have become promising candidates due to their high polarization, dielectric tunability, environment‐friendly composition, and so forth. Herein, the relaxor ferroelectric ceramics of Bi0.5Na0.5TiO3–SrTiO3–Bi(Mg0.5Zr0.5)O3 were prepared via solid‐state reaction method. The sample with optimal composition not only retains the high polarization by introducing Bi3+ ions, but also achieves the reduced remanent polarization by enhancing relaxor behavior and the promoted electric breakdown strength by the grain size refinement. Accordingly, a high recoverable energy density of 8.3 J/cm3 under 450 kV/cm and the superb charge/discharge properties (current density CD = 1200 A/cm2, power density PD = 150 MW/cm3, charge/discharge time t0.9 = 0.15 µs) are achieved, revealing great prospect in energy storage applications. [ABSTRACT FROM AUTHOR]

Bismuth sodium titanate (Bi0.5Na0.5TiO3)-based relaxor ferroelectric ceramics have received ever-increasing interest for their potential application in dielectric capacitors owing to their sterling energy storage capability. Herein, the perovskite end-member Ba(Fe0.5Nb0.5)O3 (BFN) was incorporated into 0.7Bi0.5Na0.5TiO3-0.3SrTiO3 (0.7BNT-0.3ST) ceramics to improve the relaxor characteristics and refine the grain, leading to slim polarization–electric field (P–E) hysteresis loops and enhanced electric breakdown strength. Particularly, the 0.85(0.7BNT-0.3ST)-0.15BFN ceramics achieved a high recoverable energy density of 5.7 J/cm3 and a high energy storage efficiency of 86.4% under a moderate electric field of 390 kV/cm. Additionally, remarkable stability in frequency, cycling, and temperature and excellent charge/discharge behavior were achieved at the same time. The above findings reveal that BFN-modified BNT-ST ceramics display greatly improved comprehensive energy storage properties, making them promising candidates in the field of electrostatic energy storage. [ABSTRACT FROM AUTHOR]

Textured relaxor-PbTiO3 (PT) ceramics possess advantages of crystal-like properties, high composition homogeneity, and low cost, and have, thus, received considerable attention from the piezoelectric community. To promote the applications of textured relaxor-PT ceramics, here we characterize the full electromechanical parameters (elastic, dielectric, and piezoelectric coefficients) and the frequency dependence of the coercive field (EC) for the recently reported textured Pb(In1/2Nb1/2)O3-Pb(Sc1/2Nb1/2)O3-PbTiO3 (PIN-PSN-PT) ceramic. Our results show that the textured PIN-PSN-PT ceramic possesses high piezoelectric coefficients (d31 = −365 pC N−1, d33 = 770 pC N−1, and g33 = 40.4 × 10−3 m2 C−1) and electromechanical coupling factors (k33 = 87% and kp = 82%), far outperforming those of the commercial ceramic PZT-5H (d31 = −274 pC N−1, d33 = 593 pC N−1, g33 = 1.97 × 10−2 m2 C−1, k33 = 75%, and kp = 65%). In addition, the textured PIN-PSN-PT ceramic exhibits lower dielectric constants (ɛ33S = 478) compared with PZT-5H and relaxor-PT crystals, which can greatly promote the sensitivity of receiving transducers. Moreover, the textured PIN-PSN-PT ceramic with a high Tr−t (172 °C) shows better thermal stability compared to commercial relaxor-PT crystals (Tr−t < 130 °C). The results presented here will benefit the development of piezoelectric devices made of textured ceramics. [ABSTRACT FROM AUTHOR]

An electrostatic capacitor has been widely used in many fields (such as high pulsed power technology, new energy vehicles, etc.) due to its ultrahigh discharge power density. Remarkable progress has been made over the past 10 years by doping ferroelectric ceramics into polymers because the dielectric constant is positively correlated with the energy storage density. However, this method often leads to an increase in dielectric loss and a decrease in energy storage efficiency. Therefore, the way of using a multilayer structure to improve the energy storage density of the dielectric has attracted the attention of researchers. Although research on energy storage properties using multilayer dielectric is just beginning, it shows the excellent effect and huge potential. In this review, the main physical mechanisms of polarization, breakdown and energy storage in multilayer structure dielectric are introduced, the theoretical simulation and experimental results are systematically summarized, and the preparation methods and design ideas of multilayer structure dielectrics are mainly described. This article covers not only an overview of the state‐of‐the‐art advances of multilayer structure energy storage dielectric but also the prospects that may open another window to tune the electrical performance of the electrostatic capacitor via designing a multilayer structure. [ABSTRACT FROM AUTHOR]

Dielectric materials with high permittivity and low dielectric loss have a range of promising applications within electronic devices. Here, we report on Zr co-doped (Ga 0.5 Nb 0.5) 0.03 Ti 0.97 O 2 ceramics, fabricated using a solid-state reaction. The colossal permittivity (CP) of (Ga 0.5 Nb 0.5) 0.03 -(Zr x Ti 1-x) 0.97 O 2 ceramics was investigated (x = 0%, 1%, 4%, 6%, 10%, 20%). When the doping value of Zr was 4%, the dielectric loss was reduced to 0.098 and, at room temperature and at a frequency of 1000 Hz, the dielectric permittivity was recorded as 2420. In addition, the material's dielectric permittivity exhibited good stability at temperatures ranging from −50 °C to 200 °C. Using X-ray photoelectron spectroscopy (XPS) and Scanning electron microscopy (SEM), we have observed that Zr doping reduces grain size and increases grain boundary regions. According to our XPS and impedance analysis, Zr doping also reduces the concentration of oxygen vacancies, which are considered to be the main cause of dielectric loss. We believe that the Zr doping is an effective method for reducing the dielectric loss of CP materials. [ABSTRACT FROM AUTHOR]

In order to meet the demand for miniaturized devices, ferroelectric ceramics with micro- or nano-crystal particle size are among the primary needs. In this work, we fabricated 5 mol.% cerium-doped BaTiO (CBTO) nanofibers by using sol-gel combined with electrospinning. The mechanism of doping has been investigated in detail by multiple methods. In addition, the dielectric and ferroelectric properties of the obtained CBTO ceramics fabricated by these nanofibers were investigated. Their phase transition temperature shifted to a lower temperature due to the cerium dopant and size effects. An obvious decrease of ferroelectricity of the ceramics was observed, possibly due to the existence of polar nano-regions and cerium ions. The lower curie temperature of CBTO ceramics makes it possible for over-temperature protection applications. [ABSTRACT FROM AUTHOR]

Abstract: Sr0.7Ba0.3Nb2O6 (SBN70) ceramics were prepared by conventional sintering (CS) and microwave sintering (MWS) techniques. High-density ceramics were obtained by the MWS method in 2h of cycle time, whereas it took 14h by the CS method. Samples prepared by both sintering techniques showed single phase formation according to XRD results. It was observed that MWS SBN70 ceramics showed better densification and more uniform grain size than those of CS samples. The dielectric characteristics of both samples showed diffuse phase transition phenomenon features, which was confirmed by linear fitting of the modified Curie–Weiss law. Besides, the relaxor ferroelectric properties of both samples followed the Vogel–Fulcher relationship well. The value of spontaneous polarization (P s) and the P–E hysteresis loop for MWS samples were significantly higher and slimmer than those of the CS samples, respectively. [Copyright &y& Elsevier]

Abstract: A conventional solid-state reaction was used to synthesize (1-x) Sr0.7Ba0.3Nb2O6–xBaTiO3 (0.00≤x≤0.10) ceramics. The phase structure, microstructure, and dielectric and relaxor ferroelectric properties of these ceramics were investigated. Tungsten bronze structure can be observed in ceramics, and addition of BaTiO3 can make the grain size decrease and the porosity increase. The dielectric characteristics show diffuse phase transition phenomena for all samples, which were demonstrated by a linear fit of the modified Curie-Weiss law with γ varying between 1.54 and 1.88. As the BaTiO3 content increases, the transition temperature (T C ) decreases gradually and has a minimum value of 37.53°C at composition x=0.06, and the maximum dielectric constant (ε max ) increases gradually from 66 to 3309 and subsequently decreases to 1625 at x=0.10. In addition, the relaxor ferroelectric properties of these ceramics at x=0.8 are consistent with the Volgel-Fulcher relationship; polarization versus electric field ( P-E ) loops were measured at a different temperature. [Copyright &y& Elsevier]

As one of the important electronic components, the dielectric capacitors for energy storage applications have been extensively studied in recent years. Among various dielectric materials, the perovskite oxide Bi0.5Na0.5TiO3‐based ceramics have become promising candidates due to their high polarization, dielectric tunability, environment‐friendly composition, and so forth. Herein, the relaxor ferroelectric ceramics of Bi0.5Na0.5TiO3–SrTiO3–Bi(Mg0.5Zr0.5)O3 were prepared via solid‐state reaction method. The sample with optimal composition not only retains the high polarization by introducing Bi3+ ions, but also achieves the reduced remanent polarization by enhancing relaxor behavior and the promoted electric breakdown strength by the grain size refinement. Accordingly, a high recoverable energy density of 8.3 J/cm3 under 450 kV/cm and the superb charge/discharge properties (current density CD = 1200 A/cm2, power density PD = 150 MW/cm3, charge/discharge time t0.9 = 0.15 µs) are achieved, revealing great prospect in energy storage applications. [ABSTRACT FROM AUTHOR]

Textured perovskite ferroelectric ceramics have attracted considerable attention from both academia and industry. In a recent study, an interesting phenomenon was observed in textured perovskite ferroelectric ceramics, i.e. the planar Poisson's ratios of these ceramics ranged from − 0.05 to 0.1, much lower than those of their non-textured counterparts (0.3–0.4). In this study, we fabricated a < 001 > -textured Pb(In 1/2 Nb 1/2)O 3 –Pb(Mg 1/3 Nb 2/3)O 3 –PbTiO 3 ceramic using 5 vol% BaTiO 3 templates. By studying the orientation dependence of Poisson's ratio, we found that the < 001 > -oriented grain exhibits a large anisotropy of planar Poisson's ratio, where some orientations even show negative Poisson's ratio, and the lowest Poisson's ratio is present as the x-axis is along < 110 > directions. Based on these results, the near-zero Poisson's ratio was attributed to the intrinsic microstructural feature of < 001 > -textured perovskite ceramic, i.e. the out-of-plane orientation of most grains is along the < 001 > crystallographic direction and the in-plane orientations of the grains are randomly distributed. [ABSTRACT FROM AUTHOR]

Abstract: Lead-free perovskite type (Ba0.94Bi0.06)(Ti0.94Cr0.06)O3 (BBTC) ceramics have been prepared by the conventional mixed oxide method. The XRD results showed that BBTC ceramics have single phase tetragonal symmetry with space group P4mm. Dielectric studies exhibited a diffuse phase transition characterized by a strong temperature and frequency dispersion of permittivity. The quantitative characterization based on empirical parameters (ΔT m , γ, ΔT relax , and ΔT dif ) confirmed its relaxor nature. The origin of relax ferroelectric behavior is caused by the polar nanoclusters, which were arose due to the heterovalent substitutions of Bi3+ and Cr3+ at Ba2+ and Ti4+ sites. The P–E loops obtained at the temperature quite above T m supported the diffuse phase transition behavior of the samples. [Copyright &y& Elsevier]

Abstract Excellent electric energy discharging efficiency and fatigue resistance are two critical factors in high energy storage capacitor for electronic device and high-power system with fast charging-discharging speed. Here, we report on designing and preparing the thick films of BaZr 0.2 Ti 0.8 O 3 (BZT20) bilayer ceramics (BLCs) (∼40 μm in thickness) using a tape casting method. In this ABO 3 -structured perovskite ceramics, the B position of Ti was occupied by 20 mol% Zr atoms, which leads to order-disordering and random fields in the single phase with both the tetragonal (space group P 4 mm) and rhombohedral (space group m-3m). And therefore, the relaxors possess a heterogeneous polar state at the nanoscale and their long-range domains are disrupted. Consequently, a non-hysteretic arc-shaped unipolar polarization-electric frield loop (P-E loop) in which the curve obtained under a considerable high electric field of 80 MV m−1 and the curve under depolarization are overlaped. As such, a large energy storage density (U e) of ∼6.2 J cm−3 with the discharging efficiency of ∼98% and a considerable fatigue resistance over 22 k cycles at a wide temperature range from 253 to 393 K (−20 °C–120 °C) are obtained. The attractive electric performance of this BLCs films demonstrates that this sort of relaxor ceramics is one of promising materials for capacitors with little calorigenic electronic power areas. Highlights • Relaxor BaZr 0.2 Ti 0.8 O 3 bilayer ceramics are prepared using a tape casting method. • Non-hysteretic P-E loop curve under polarization overlaps the depolarization part. • A large energy density of ∼6.2 J cm−3 with the efficiency of ∼98% is obtained. • A considerable fatigue resistance of 22 k cycles at −20 °C to 120 °C is obtained. [ABSTRACT FROM AUTHOR]