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Ceramic-based capacitors with excellent recoverable energy storage density (Wrec) and efficiency (η) are greatly desired for pulsed capacitors but challenge as well. In this work, the high energy storage performance with an Wrec of 5.1 J/cm3, an η of 93.4%, and an ultrafast discharge–charge speed t0.9 of 72 ns is achieved in unusual interstitial and substitutional hybrid solid solution of Sr0.64Bi0.18Na0.18TiO3-ZnO (SBNT-Zn), in which two Zn2+ ions occupy one A-site, while one Zn2+ ion occupies one B-site of ABO3 perovskite lattice simultaneously. The addition of Zn2+ increases lattice distortion and breaks long-range ferroelectric order, resulting in more highly dynamic polar nanoregions, higher relaxation behaviors as well as larger polarization (ΔP). Moreover, the extraordinary hybrid solid solution configuration enhances the bandgap of SBNT-Zn and ZnO as a sintering aid refines grain size, both help to enhance electric breakdown strength. This work affirms the feasibility and reliability of forming a hybrid solid solution to develop high-performance ferroelectric materials. [ABSTRACT FROM AUTHOR]

The enhanced and reliable high-power performance of x Pb(Mn 1/3 Nb 2/3)O 3 –(1- x)Pb(Zr 0.5 Ti 0.5)O 3 –0.5mol%Co 2 O 3 piezoelectric ceramics (x PMN–(1- x)PZT–Co; x = 0.04–0.10) has been achieved. It is noteworthy that the vibration velocity (υ 0) of the 0.08PMN–0.92PZT–Co ceramic reaches up to 0.9 m/s, which is 2.25 times that of commercial PZT4 ceramics (∼0.4 m/s). The high υ 0 of the 0.08PMN–0.92PZT–Co ceramic is attributed to its excellent electromechanical parameters: d 33 = 405 pC/N, Q m = 1405, and k p = 0.61. The 0.08PMN–0.92PZT–Co ceramic achieves a relatively low high-field tan δ (tan δ = 3.74% at 500 V/mm), thereby suppressing heat generation. Additionally, the significantly high Curie temperature (T c) value of 346 °C for the 0.08PMN–0.92PZT–Co ceramic stabilizes the ferroelectric phase. Therefore, the 0.08PMN–0.92PZT–Co ceramic exhibits long-term reliable high-power performance by maintaining a stable υ 0 of 0.9 m/s and slight temperature rise within 100 min. [ABSTRACT FROM AUTHOR]

Relaxor ferroelectric 0.94Na0.5Bi0.5TiO3‐0.06BaTiO3‐modified antiferroelectric Pb0.99Nb0.02[(Zr0.57Sn0.43)0.94Ti0.06]0.98O3 ceramics, (1−x)PNZST‐x(BNT‐6BT), were prepared to acquire high energy storage and thermal stability properties. X‐ray diffraction and element mapping revealed that a solid solution between PNZST and BNT‐6BT occurs, and Ti cations enter the PNZST lattice, partly extruding Sn cations and leading to the formation of isolated SnO2 particles at the grain boundaries and a 0‐3 type composite structure. Such a composite structure helps to create deviatoric stress in the solid solution component. The BNT‐6BT content significantly influences the energy storage capacity, and the x = 0.2 composition renders optimal performance. The room‐temperature‐recoverable energy density and energy efficiency are 2.23 J/cm3 and 78%, respectively, at 260 kV/cm. Both parameters vary less than 6% within a temperature range of 25°C and 125°C. The improved energy storage and temperature stability indicate that the ceramics can potentially be applied in pulse power capacitors and that this relaxor‐modified antiferroelectric ceramic preparation method is a valuable reference for further optimizing the functional properties. [ABSTRACT FROM AUTHOR]

(Na0.5Bi0.5)0.93Ba0.07Ti1 − x(Mn1/3Nb2/3)xO3 ceramics (x = 0–0.02) were prepared, and their structure and property were investigated systematically. (Mn1/3Nb2/3)4+ doping shifts ferroelectric–relaxor transition temperature (TF–R) toward low temperature. Thus, ferroelectric order is suppressed and relaxor behavior is enhanced monotonously, as further evidenced by composition-dependent electrical properties and domain evolution from labyrinthian to nanodomain. As a result, the x = 0.010 ceramic yields a large room temperature field-induced strain of 0.37%, especially the strain is temperature- and frequency-insensitive with a variety of 4.3% and 4.1% in the ranges of 25–125 °C and 0.5–10 Hz, respectively. This work suggests that the low content (Mn1/3Nb2/3)4+ complex cation doping is an alternative method to effectively tune the electrical properties of Na0.5Bi0.5TiO3-based ferroelectrics. [ABSTRACT FROM AUTHOR]

The design and experiment of a pulsed Ka-band TE01-mode gyrotron traveling-wave tube are presented. This tube was designed to use the fundamental cyclotron resonance interaction with TE01 cylinder waveguide mode. Backward-wave oscillations of various origins were suppressed by ceramic loading technology. With the electron beam voltage of 66 kV and a beam current of 11 A, a saturated peak power of 110 kW was measured at 33.9 GHz, corresponding to a saturated gain of 34.4 dB, with a −3-dB bandwidth of 1.75 GHz. [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]

(1−x)Sr0.75Ba0.25Nb2O6–xNaNbO3 (x = 0–0.8) ceramics were prepared by the traditional solid-state reaction method. The x = 0–0.4 ceramics preserve the tungsten bronze phase with a gradually unfilled–filled structure evolution accompanying a relaxor-normal ferroelectric transition. This transition process is accompanied by an increase in the maximum dielectric constant temperature or Curie temperature (Tc), enhancement of room temperature ferroelectric and piezoelectric properties, and appearance of the stripe domain. On the other hand, ceramics with x > 0.4 consist of coexisting tungsten bronze and perovskite phases, for which Tc slightly fluctuates, and the ferroelectric and piezoelectric properties decrease with increasing x. This work provides a feasible way to manipulate the relaxor-normal ferroelectric transition and the electrical properties of the tungsten bronze family. [ABSTRACT FROM AUTHOR]

Solid solution ceramics of (1- x)Sr 0.75 Ba 0.25 Nb 2 O 6 - x PbZr 0.52 Ti 0.48 O 3 (x = 0−0.4) were prepared and investigated. The phase evolves from tungsten bronze for x = 0, coexisted tungsten bronze and pyrochlore at x = 0.3, to pyrochlore for x > 0.3. As the results, the ceramics show dramatically composition dependent microstructure and electrical property. The grain shape changes from anisotropic pillar-like with maximum length-diameter ratio of 3.3 at x = 0.2 to isotropic cubic-like for x > 0.2. At the same time, the maximum dielectric constant temperature tends to decrease with an exceptional increase at x = 0.3 due to the coexisted phases. Interestingly, the x = 0.3 ceramic endures ultrahigh breakdown strength of 340 kV/cm, which, together with enhanced polarization, results in maximum recoverable energy storage density of 3.0 J/cm3and energy storage efficiency of 81.5 % at room temperature. [ABSTRACT FROM AUTHOR]

(1- x)(Pb 0.97 La 0.02)(Zr 0.5 Sn 0.4 Ti 0.1)O 3 - x (Na 0.5 Bi 0.5) 0.94 Ba 0.06 TiO 3 (x = 0 ∼ 0.4) ceramics have been prepared and investigated. The ceramics consist of perovskite solid solution matrix and precipitated, isolated SnO 2 particle, resulting in 0–3 type composite structure. With increasing x value, the room temperature crystal structure of perovskite solid solution transforms from tetragonal to pseudocubic, therefore, the electrical property evaluates form robust antiferroelectric at x = 0, metastable antiferroelectric at x = 0.1, and then relaxor ferroelectric at x > 0.1. Moreover, the breakdown strength is enhanced due to the composite structure and reaches maximum value of 190 kV/cm at x = 0.2. Both the phase transition and enhanced breakdown strength are helpful to improve energy storage property, the x = 0.2 ceramic shows largest recoverable energy density w rec of 1.84 J/cm3, discharge efficiency η of 86.6 %. Especially, both w rec and η illustrates significantly improved thermal stability within 25−125 °C. [ABSTRACT FROM AUTHOR]

Ba 0.70 Ca 0.30 Ti 1- x (Nb 0.5 Fe 0.5) x O 3 lead-free ceramics (abbreviated as BCTNF x , x = 0–0.12) were prepared by solid-state reaction method. The influence of B-site (Fe 0.5 Nb 0.5)4+ substitution on phase structure, microstructure, dielectric, ferroelectric and piezoelectric properties of Ba 0.70 Ca 0.30 TiO 3 ceramics were systematically studied. The BCTNF x ceramics consist of diphasic tetragonal (T) and orthorhombic (O) phases at x = 0–0.04, pseudocubic (PC) and O phases at x = 0.05–0.08, cubic (C) and O phases at 0.08 < x ≤ 0.12. Increase of (Fe 0.5 Nb 0.5)4+ doping improves sinterability, depresses the ferroelectric - paraelectric phase transition temperature (T m) monotonically from 128 °C at x = 0 to -86 °C at x = 0.12, induces enhanced relaxor behavior and weakens piezoelectric properties. The room temperature relative dielectric constant (ε r) and dielectric loss tangent (tan δ) increase with increasing x and reach the maximum values of 4869 and 0.06 respectively at x = 0.06. Whereas the average grain size (abbreviated as AGS), ferroelectric properties and electric field induced strain increase significantly by introducing 2.0 mol% B-site complex cations (Fe 0.5 Nb 0.5)4+ into Ba 0.70 Ca 0.30 TiO 3 ceramics. The BCTNF0.02 ceramics achieve optimal electrical properties with ε r = 1268, tan δ = 0.03, T m = 102 °C, P max = 12.8 μC/cm2, P r = 6.1 μC/cm2, E C = 6.0 kV/cm, d 33 = 117 pC/N, k p % = 0.18%, Q m = 236, bipolar S max % = 0.20%, unipolar S max % = 0.16% and d 33 ∗ = 314 pm/V. The variation of electrical properties of BCTNF x ceramics is attributed to the combined action of grain size effect, phase transition, weakness of octahedral distortion, clamping effects of the internal bias electric field E i on domain wall motion induced by B-site cations (Fe 0.5 Nb 0.5)4+ displacement. [ABSTRACT FROM AUTHOR]

Composite ceramics based on non-stoichiometric 0.94Na 0.48 Bi 0.44 TiO 3 (NBT-BT) and ZnO, (1- x)NBT-BT: x ZnO with x = 0 ∼ 0.3 are prepared and investigated. The phase structure changes from tetragonal-dominated for x = 0 to rhombohedral-dominated for x > 0. The domain structure simultaneously evolves from nanodomain to macrodomain. At room temperature, the x = 0 ceramic has a pinched polarisation-electric field (P-E) loop, whereas x > 0 ceramics demonstrate square-shaped P-E loops with a maximum P r of 30.6 μC/cm2 of x = 0.2. Moreover, ceramics with x = 0.1 and 0.2 have enhanced pyroelectric coefficients in a wide temperature range with full width at half maximums of 31 °C and 15.5 °C and peak values of 29.2 × 10−4 and 100.7 × 10−4 C/(m2·K), respectively. The results are explained based on the stress-induced room temperature relaxor-ferroelectric transition. This work affirms that forming composites is an effective way to tune the electrical properties of NBT-based materials. [ABSTRACT FROM AUTHOR]

The doping of ZnO is efficient to improve the piezoelectric property and thermal stability of Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) based ceramics. However, the underlying physics, especially the local domain structures of the ZnO modified PMN–PT ceramics, which is strongly associated with the electric properties, is not clear yet. In this paper, we investigated the local domain structures and their evolution as a function of x in PMN–0.32PT:xZnO ceramics. It was found that, the domain evolution is mainly caused by the growth of grain size induced by the sintering aiding effect of ZnO at x < 0.04, and the domain evolution can be attributed to the phase transition induced by the partial replacement of Mg2+ by Zn2+ in the B‐site of PMN–PT lattice at x > 0.06. Furthermore, we also investigated the domain structure evolution as functions of temperature and local external electric field in PMN–0.32PT:0.06ZnO ceramics, which exhibited superior piezoelectric property relative to other compositions. We found that the irregular nanodomains are more stable at high‐temperature range, and the regular non‐180° domains exhibited more complex rotation behavior under local electric field, which probably leads to the thermal stability and piezoelectric property enhancement in the ZnO‐modified PMN–0.32PT ceramics. [ABSTRACT FROM AUTHOR]

Highlights • A new ceramic by introducing Bi(Mn 0.5 Ti 0.5)TiO 3 into 0.8Bi 0.5 Na 0.5 TiO 3 -0.2Bi 0.5 K 0.5 TiO 3 is prepared via solid state reaction method. • The compositions within x = 0.03–0.055 exhibit large strain of 0.31% ˜0.41% and electrostrictive coefficient of 0.027–0.041 m4/C2. • At x = 0.04, the large strain and electrostrictive coefficient are nearly temperature-independent in the range of 25–100 °C. Abstract (1- x)[0.8Bi 0.5 Na 0.5 TiO 3 -0.2Bi 0.5 K 0.5 TiO 3 ]- x Bi(Mn 0.5 Ti 0.5)O 3 (x = 0–0.06, BNKMT100 x) lead-free ferroelectric ceramics were prepared via solid state reaction method. Bi(Mn 0.5 Ti 0.5)O 3 induces a structure transition from rhombohedral-tetragonal morphotropic phases to pseudo-cubic phase. Moreover, the wide range of compositions within x = 0.03–0.055 exhibit large strain of 0.31%–0.41% and electrostrictive coefficient of 0.027–0.041 m4/C2. Especially, at x = 0.04, the large strain and electrostrictive coefficient are nearly temperature-independent in the range of 25–100 °C. The impedance analysis shows the large strain and electrostrictive coefficient originate from polar nanoregions response due to the addition of Bi(Mn 0.5 Ti 0.5)O 3. [ABSTRACT FROM AUTHOR]

High impact velocity of particles has found its common way into the vacuum cold spray (VCS), but heating gas may further intensify this function, resulting in significantly higher impact velocity. That's the original design idea to realize denser ceramic deposition at low temperature in this paper. In this study, a ~ 10 µm thick La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3 (LSGM) electrolyte layer for SOFCs is prepared by VCS under heated gas. The effects of gas temperature on the deposition behavior, mechanical and electrical properties of the coatings are investigated. Results show improvements in coating density, hardness and ionic conductivity at elevated temperature. Additionally, the output performance of cell with LSGM electrolytes deposited at gas temperature of 400 °C achieved an open circuit voltage of ~ 1.0 V and the maximum power density of 855 mW/cm 2 at 750 °C. Overall, these findings testify of the promising aspects of VCS method for preparing solid electrolyte films for IT-SOFCs. [ABSTRACT FROM AUTHOR]

Lead-free ceramic-based dielectric capacitors with high-performance energy storage properties have become an emerging issue recently as a result of the applications in high-power and/or pulsed-power technologies. However, the trade-off between various parameters, such as maximum polarization P max , remnant polarization P r and dielectric breakdown strength E b , restricts the further improvement of the energy storage properties of dielectric ceramics. Herein, a synergistic optimization strategy via simultaneous enhancement of P max and E b and reduction of P r is adopted to achieve outstanding energy storage properties for Bi 0.9 La 0.1 FeO 3 -Ba 0.7 Sr 0.3 TiO 3 NaNb 0.85 Ta 0.15 O 3 relaxor ferroelectric ceramics, characterized by an ultrahigh recoverable energy density W rec of 15.9 J/cm3 and high efficiency η of 87.7%. The inborn gene of BiFeO 3 -based materials results in high P max and the improved relaxor behavior gives rise to a small P r value. In Particular, a very large value for E b is obtained by tailoring multiple intrinsic and extrinsic factors. These results demonstrate the reliability and feasibility of the multiple optimization strategy proposed in this work to develop novel dielectric ceramics for advanced energy storage applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Ferroelectric/polar semiconductor BaTiO 3 : x ZnO composites (BT: x ZnO) have been prepared and investigated. The ZnO particles distribute at the BT grain boundaries to form 0–3 type composites, i.e., the isolated 0-dimensional ZnO particles are embedded in the 3-dimensional BT matrix. With increasing ZnO content, the Curie temperature keeps constant, however, both the dielectric constant and ferroelectric polarization of the composites increase, reaching the maximum at x =0.3, and then tend to decrease. Furthermore, the composite has improved temperature stability of ferroelectric polarization and field-induced strain up to ~100 °C. It is believed that ZnO can induce a built-in electric field which has influence on the domain switching and thus on the observed composition- and temperature-dependent electrical properties. This work may provide some new clues for developing ferroelectric composites with high performance. [ABSTRACT FROM AUTHOR]

● PLZST: x SnO 2 composite ceramics were prepared by solid state reaction. ● The composite structure had significant effects on microstructures and electrical properties. ● The optimal composition of x = 0.2 showed high energy storage density of 2.38 J/cm3. Constructing composite structure is an effective way to improve dielectric energy storage properties. However, ionic diffusion between composite members is generally inevitable, which mixes the effects of solid solution with composite structure on property to some extent. To exclude the ionic diffusion effect as much as possible, antiferroelectric (Pb 0.97 La 0.02)(Zr 0.5 Sn 0.4 Ti 0.1)O 3 (PLZST) was sintered at a relatively high temperature to precipitate SnO 2 particles, then more SnO 2 were introduced to from (1- x)PLZST: x SnO 2 (x = 0–0.25) composite. The results showed that composite structure had significant effects on microstructures and properties with changed lattice parameter, decreased grain size, increased Curie temperature, suppressed antiferroelectric property, and enhanced electric breakdown strength. The optimal composition of x = 0.2 showed high energy storage density of 2.38 J/cm3. This work provides a robust platform to investigate the effect of composite microstructure on electrical properties, which is helpful for further developing high performance composite materials. [ABSTRACT FROM AUTHOR]