In this work, highly textured 0.33Pb(Ni1/3Nb2/3)O3-xPbZrO3-(0.67-x)PbTiO3 ceramics were fabricated via low-temperature sintering without the use of sintering aids. Though composition optimization, the textured x = 0.27 ceramics demonstrate outstanding comprehensive properties (d33 = 1050 pC/N, Tc= 207 degrees C, d33* = 1097 pm/V, kp = 0.73, k33 = 0.83). To elucidate the origin of the enhanced electromechanical properties, the domain configuration and lattice distortion in the textured x = 0.27 ceramics were investigated using high-angle annular dark-field scanning transmission electron microscopy. The results reveal that the crystallographic anisotropy, refined stripe domains, and atomic-scale lattice distortion heterogeneity induced by texturing collectively facilitate polarization rotation and domain wall motion. This synergistic effect leads to a flattened free-energy landscape, which enhances piezoelectric and electromechanical coupling properties without lowering the Tc. Furthermore, multilayer textured ceramics were successfully fabricated, and their strain characteristics were studied. A large strain of 0.331% was achieved under an electric field of 50 kV/cm, demonstrating its excellent potential for multilayer piezoelectric actuator applications. (c) 2026 Published by Elsevier B.V. on behalf of The Chinese Ceramic Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

ABSTRACT In practical piezoelectric actuators, materials are required to exhibit large electrostrain for substantial displacement output while maintaining low strain hysteresis to ensure high positioning accuracy. However, these two performance metrics are often mutually exclusive. This study employs hierarchical domain structure engineering to synergistically regulate electrobending‐induced strain amplification and domain switching behavior, thereby overcoming the aforementioned trade‐off. Based on phase‐field simulations, a hierarchical domain structure constructed by embedding micron‐scale lamellar domains within a nanodomain matrix is demonstrated to simultaneously optimize strain magnitude and strain hysteresis. Furthermore, the magnitude of the bending response is found to be governed not only by oxygen vacancy concentration but also by the domain structure. Compared with polar nanoregions, lamellar domains are more susceptible to pinning by oxygen vacancies, leading to heterogeneous strain distribution and electrobending deformation. Specifically, the (Bi 0.5 Na 0.5 ) 0.7 Sr 0.3 Ta 0.002 Ti 0.998 O 3 sample exhibits the optimal overall performance, achieving an apparent strain of ∼0.74%, an apparent large‐signal piezoelectric coefficient of 1067 pm/V, and a low hysteresis rate of ∼21%, demonstrating superior strain–hysteresis synergistic optimization compared with the undoped and excessively Ta‐doped samples. These results demonstrate that hierarchical domain design and electrobending engineering provide a viable strategy for synergistically achieving large strain and low hysteresis, offering a new pathway for high‐performance piezoelectric bending actuators.

High-power PZT-based piezoelectric ceramics with high electromechanical properties are in urgent demand in the market. In this study, Mn ions were introduced into 0.36 Pb(Ni1/3Nb2/3)O-3-0.28PbZrO(3)-0.36PbTiO(3) (PNN-PZT) ceramics in the form of Pb(Mn1/3Nb2/3)O-3 (PMnN) to synthesize a quaternary piezoelectric ceramic (xPMnN-PNN-PZT) with coexistence of rhombohedral and tetragonal phases. The addition of PMnN caused the grain sizes to continuously decrease from 3.29 mu m to 1.58 mu m. However, the density first increased and then decreased, reaching a maximum value of 8.02 g/cm(3) at x = 0.07. The increased internal bias field (E-i) and domain size suppressed the domain wall motion and domain switching, reducing internal friction and improving the mechanical quality factor (Q(m)). Compared with Q(m) similar to 146 of undoped PNN-PZT ceramics, the maximum Q(m) of 0.07PMnN-PNN-PZT reached approximately 2244. And the Vickers hardness of xPMnN-PNN-PZT ceramics was promoted from similar to 356 HV (x = 0) to similar to 480 HV (x = 0.07). In addition, the other optimal electromechanical performances: piezoelectric coefficient d(33) = 202 pC/N, planar electromechanical coupling coefficient k(p) = 0.45, Curie temperature T-c = 198 and dielectric loss tan delta = 0.0059 were also achieved at x = 0.07. This work provides a feasible way for the development and application of high-power piezoelectric ceramics.

The attainable piezoelectric properties of ferroelectric ceramics depend on the degree of poling, in which domain reorientation occurred to align all polarizations. Conventional poling cannot fully pole the ceramic due to the strain generated during the non-180 degrees domain reorientation. The 0.35Pb(Ni1/3Nb2/3)O3-x(Pb0.92Ba0.04Sr0.04) ZrO3-(0.65-x)(Pb0.92Ba0.04Sr0.04)TiO3 piezoceramic with x = 0.26 demonstrates remarkable piezoelectric performance when subjected to high-temperature poling at 150 degrees C under 1 kV/mm, achieving an ultra-high piezoelectric coefficient d33 of 1280 pC/N, along with remnant polarization Pr of 25.4 mu C/cm2. Notably, the obtained d33 value exhibits a 31.4 % enhancement compared to traditional poled samples (d33 = 974 pC/N, Pr = 24.2 mu C/cm2, epsilon r = 5641). For the x = 0.24 sample, high-temperature poling can simultaneously achieve very large piezoelectric coefficient (d33 = 983 pC/N) and high temperature stability (Delta d33/d33-RT = 4.88 % up to 65 degrees C). The enhancement mechanism of high-temperature poling is due to the formation of much smaller domains.

To meet the escalating demands for high-performance piezoelectric materials in fields such as modern medical diagnostics, precision manufacturing, etc., we developed a ternary 0.555Pb(Ni1/3Nb2/3)O-3-0.145PbZrO(3)-0.30PbTiO(3) (PNN-PZ-PT) piezoelectric ceramic located at the tricritical point of rhombohedral, tetragonal and pseudocubic phases. This ceramic, with coexistence of multiple ferroelectric phases, demonstrates an ultrahigh piezoelectric coefficient d(33 )of 1190 picocoulombs per newton (pC/N) and a large relative dielectric constant epsilon(r) of 9900. Analysis of the domain structure reveals irregular maze-like nanodomains with strong local disorder. These nanodomain structures exhibit excellent local piezoelectric response and polarization switching characteristics, thereby enhancing the alignment of polarization vectors during poling and ensuring the high stability after being poled. The tricritical point composition with disordered nanodomains can significantly enhance the contribution of polarization to macroscopic piezoelectric properties, offering a promising approach for developing ceramics with superior piezoelectricity.

Recently, large apparent strain resulting from bending deformation in thin piezoelectric ceramics has attracted significant attention. However, whether oxygen vacancies or defect dipoles contributes to such macroscopic deformation remains controversial. In this study, bending deformation in (Na0.81 K0.19 )0.5 Bi0.5 Nb0.01 Ti0.99 O3 ceramics is investigated, and the underlying microscopic mechanisms are clarified. X-ray photoelectron spectroscopy analysis indicates a gradient distribution of oxygen vacancy concentration across both the thickness and radial directions of the ceramic. And piezoresponse force microscopy confirms that the top and bottom surfaces of the sample exhibit different domain mobility. Furthermore, it is demonstrated that the oxygen vacancy concentration gradient along the thickness direction plays a decisive role in inducing the bending deformation. Based on these findings, a mechanism for bending deformation is proposed. The gradient in oxygen vacancy concentration along the thickness direction of the ceramic induces spatially non-uniform domain switching during polarization, leading to differential contraction between the top and bottom surfaces and ultimately resulting in macroscopic bending deformation. This study establishes a comprehensive mechanistic chain spanning from oxygen vacancy migration (microscopic) to inhomogeneous domain switching (mesoscopic) and finally to macroscopic bending deformation, providing a crucial theoretical foundation for the design of piezoelectric materials with large electrostrain. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

The introduction of oxygen vacancies and defect dipoles to induce giant bending strain is a cutting-edge strategy to improve the performance of piezoelectric ceramics. However, its feasibility in a more widely used multi-layer structure is still unknown. In this study, it is found that the giant strain successfully achieved in single-layer ceramics almost disappeared in multi-layer ceramics based on the same material system. The system analysis shows that the internal mechanical clamping effect introduced by the multi-layer structure and the opposite bending direction between adjacent layers are the root causes of large strain failure. The conclusion of this study clearly points out that the excellent piezoelectric properties in unconstrained single-layer samples cannot be directly converted into the actual advantages of multi-layer devices. This finding provides a crucial application perspective correction for the current popular defect engineering research.

Understanding the intrinsic role of piezoelectricity is critical for the rational design of high-efficiency piezocatalytic systems. However, this remains challenging due to the contribution of intrinsic piezoelectricity often being obscured by complex interface effects, specific surface area (size confinement), and other coupled phenomena. In this study, we decouple these factors by employing a model system of piezoceramic thin sheets with a tunable piezoelectric coefficient (d33). We establish a direct and quantitative relationship between d33 and catalytic activity: the sheet with the highest d33 value of 754 pC N-1 exhibited a superior H2O2 production rate of 8.58 μmol h-1 and a Rhodamine B degradation rate constant of 0.073 min-1. Conversely, the sample with the lowest d33 value of 155 pC N-1 showed the minimal activity. Through carrier dynamics analysis and carrier migration simulations, we demonstrate that stronger piezoelectricity enables more efficient polarization rearrangement, greater stress sensitivity, and improved charge separation and transport. These effects lead to a higher transient free carrier concentration and a more robust built-in electric field, which ultimately accelerate the piezocatalytic reaction kinetics. This work establishes a clear and quantitative correlation between intrinsic piezoelectric properties and catalytic activity, while also delivering a high-performance, easily synthesized piezocatalytic platform for sustainable applications.

(Ba1-xCax) (Zr0.04Sn0.04Ti0.92)O3 (BCZST)-based piezoelectric ceramics were prepared using a solid-state reaction method. The refinement of microstructure significantly enhanced the piezoelectric properties of BCZST. BCZST doped with 2 mol% MnO2 exhibited an impressive mechanical quality factor (Qm) of approximately 1045, mainly attributed to the suppression of extrinsic domain switching contributions. However, the MnO2 doping also resulted in a reduction of the piezoelectric coefficient (d33) to 144 pC/N. Notably, annealing the BCZST + 2 mol% MnO2 in nitrogen led to the coexistence of multiple phases and increased the intrinsic contribution from polarization rotation. This treatment optimized both the hard and soft piezoelectric properties, yielding a Qm of 721 and a d33 of 220 pC/N. Our multiscale defect-engineering strategy presents a valuable approach for the design of lead-free piezoelectric ceramics with enhanced hardening effects suitable for high-power applications.

With the rapid development of LEO satellite constellations,LEO navigation augmentation has become a research hotspot in the field of satellite navigation.LEO navigation augmentation adopts the"satellite-based monitoring+signal augmentation"system,LEO navigation satellites need to broadcast LEO navigation augmentation signals to the ground while receiving GNSS signals.LEO navigation augmentation signals are usually broadcast in the GNSS frequency band,so the LEO navigation augmentation signal broadcast to the ground is a strong self-interference signal with respect to the received signal,and how to eliminate the effect of the self-interference signal on the received signal is the key to realizing the simultaneous transceiver in the same frequency band.The self-interference cancellation scenario and method of LEO navigation augmentation are studied,and the performance evaluation method applicable to LEO navigation augmentation self-interference cancellation is proposed for the characteristics of LEO navigation augmentation signals,which uses the correlation power difference of the interfering signals before and after self-interference cancellation to characterize the self-interference cancellation capability.The signal power value after interference cancellation is obtained through the correlation power difference,and the equivalent carrier-to-noise ratio loss and the code tracking error evaluation method under the influence of residual self-interference are derived to evaluate the influence of residual self-interference signal on the expected signal reception.A typical navigation signal BPSK(2)and BOC(1,1)are used for simulation verification,and the results show that when the interference-to-noise ratio is 30dB,the self-interference cancellation ability of the existing method is 30.98 dB and 33.04 dB,and the self-interference cancellation ability of the proposed method is 58.80dB and 58.96dB.Through comparative verification,it can be concluded that the proposed self-interference cancellation performance evaluation method outperforms existing methods.It provides a more accurate assessment of the self-interference cancellation capability in LEO navigation augmentation,serving as a performance evaluation reference for self-interference cancellation methods in this context.

KNN-based piezoelectric ceramics have great application potential in the new generation of piezoelectric detection and sensor devices due to their low acoustic impedance and preferable electrical properties. However, in practical applications, the temperature stability of piezoelectric properties and mechanical properties of ceramics are also important, which influence the reliability of piezoelectric sensor. In this work, by constructing multiscale Ag heterostructures in KNN-based ceramics, both outstanding piezoelectric properties (d(33) = 534 pC/N, k(p) = 0.65, d(33) x g(33) = 11.3 x 10(-15) m(2)/N) and in-situ d(33) temperature stability (the variation less than similar to 20 % from 25 to 100 degrees C) are achieved, showing great advantage compared with previous reports and some commercial PZT-based piezoceramics. This achievement benefits from the collaboration effect on the diffused polymorphic phase boundary (PPB) through multiscale Ag heterogeneity and alleviation of the phase transition due to deviatoric stress field. Moreover, we simultaneously realize remarkable mechanical robustness (nanoindentation Young's modulus E = 166.54 GPa, nanoindentation hardness H = 7.82 GPa, and average compressive strength ACS = 76.89 MPa), superior to many state-of-the-art commercial PZT-based ceramics. Our work may provide an effective paradigm for developing high-performance perovskite materials with high piezoelectricity, superior thermal reliability, and mechanical properties robustness for piezoelectric sensor applications.

Texture engineering is proved to be an effective strategy to enhance the piezoelectricity of piezoelectric ceramics in recent years. In this paper, a low-temperature sintered 0.24Pb(Ni[Formula: see text]Ta[Formula: see text]O[Formula: see text]PbZrO[Formula: see text](0.76[Formula: see text]PbTiO3 (PNT-PZT, [Formula: see text], 0.32 and 0.33) ceramic was studied. Texture engineering was introduced to improve the piezoelectric coefficient. Herein, [001] textured PNT-PZT ceramics were prepared at 1050∘C by templated grain growth (TGG) method using barium titanate (BaTiO[Formula: see text] platelet templates. The phase composition, microstructure, and electric properties of all ceramics were characterized in detail. The PNT-PZT ([Formula: see text]) textured ceramics shows the best comprehensive properties ([Formula: see text] [Formula: see text]pC/N, [Formula: see text] at 25∘C, [Formula: see text], [Formula: see text]C). This work provides a promising candidate material for ultrasonic transducers by texture engineering.

With the booming development of low earth orbit (LEO) satellite constellations, improving the global navigation satellite system (GNSS) performance based on LEO satellites is attracting more and more research attention. To shorten the convergence time of precise point positioning (PPP) with the help of the LEO navigation augmentation system, the dedicated LEO navigation augmentation signals need to be broadcasted, and the signals need to meet some special design requirements. This paper takes the GNSS L1 and L5 frequency bands as examples to design the LEO navigation augmentation signals. From the perspective of reducing interference to GNSS signals, the carrier frequency of the LEO navigation augmentation signal is selected, and the modulation type is designed. In order to support both high-precision measurement and high data rate, it is proposed that the LEO navigation signal consists of a measurement component and a data component with a high data rate. These two signal components are combined into one composite signal using the multiplexing code shift keying (MCSK) method. On this basis, compatibility between LEO navigation augmentation signals and GNSS signals is evaluated. The impact of LEO navigation augmentation signals on GNSS signals is further analyzed.

LEO navigation systems have the potential to supplement and back up GNSS services, and Doppler-aided positioning has been proposed to address insufficient pseudorange measures due to a lack of navigational resources or the early phases of system development. To improve Doppler-aided positioning precision, we introduce the Kalman filtering method to Doppler-aided positioning for fused LEO navigation systems. Simulation results indicate that this method and pseudorange positioning achieve comparable accuracy when more than four pseudorange measurements are available. However, when fewer than four pseudorange measurements are available, Doppleraided positioning based on Kalman filtering can maintain 95% of the three-dimensional errors within 0.5 meters. The above results mean that Doppler-aided positioning based on Kalman filtering can simultaneously maintain service availability and improve positioning precision.

Improving mechanical quality factor Qm is of great significance for high-power applications. Here, a new strategy of the [111]c texture engineering was proposed to enhance the performances of high-power piezoelectric ceramics. The 5 vol% BaTiO3 (BT) templates with the [111]c preferred orientation were introduced into matrix powders of 0.03 Pb(Mn1/3 Nb2/3 )O3 -0.33Pb(Ni1/3 Nb2/3 )O3 -0.28 PbZrO3 -0.36PbTiO3 (28PZ(R)) to form the [111]c textured ceramics (28PZ(T)), possessing a texture degree of 74 %. The multiple of uniform density in EBSD increased from 0.63 in randomly oriented 28 PZ(R) to 6.63 in 28PZ(T). The good lattice matching between BT templates and textured grains was observed using high-resolution transmission electron microscopy, confirming the microscopic origin of the [111]c texture. The maximum phase angle theta max of 88.2 degrees was quite near 90 degrees in 28PZ(T), ensuring the optimal Qm value of 1275 and the great figure of merit of 255,0 0 0 pC/N. The increased Qm in [111]c texture ceramics was confirmed due to the reduced intrinsic polarization directions rather than the pinning effect of the internal bias field. Larger grain sizes with larger domains restrained the movement of domain walls in 28 PZ(T), which was also favorable to higher Qm . This work may provide a new promising route for further high-power applications. (c) 2024 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

The development of piezoelectric ceramics characterized by both large piezoelectric response and high-temperature stability is imperative for the advancement of practical electromechanical devices. However, existing high-performance piezoelectric ceramics often encounter compromised temperature stability because ferroelectric phase transitions occur within low-temperature regions. In this work, we focused on Sm-doped Pb(Ni1/3Nb2/3)O3–PbZrO3–PbTiO3 (PNN–PZT:Sm) ceramics with a tetragonal (T)-phase structure to achieve the desired combination of high piezoelectricity and high temperature stability. The results indicate that 2 mol% Sm-doped samples exhibit a large piezoelectric constant (d33) of 575 pC/N, an effective piezoelectric strain coefficient (d33*) of 890 pm/V, and a high ferroelectric-to-paraelectric phase transition temperature (Tm) of 279 °C. Remarkably, d33 experiences only a 2.6% variation over the temperature range of 30–250 °C, while d33* changes by 8% within the temperature range of 30–180 °C. Microstructural and domain structure analyses suggest that Sm-doping effectively reduces the grain size, leading to a decreased domain size, thereby achieving excellent electromechanical properties. The superior temperature stability is attributed to the suppressive effect of Sm-doping on the R–T ferroelectric phase transition. These studies suggest that Sm-doping represents an effective strategy for achieving the collaborative optimization of piezoelectricity and temperature stability through grain and domain engineering techniques for perovskite ferroelectric materials.

xPb(Ni1/3Nb2/3)O3-(1-x)Pb(Zr,Ti)O3 (x = 0.12, 0.24, 0.36, 0.42, 0.55 and 0.64) ceramics were prepared using conventional solid-state reaction. The morphotropic phase boundary (MPB) composition region, sintering characteristics and performance parameters of ceramic samples with different PNN compositions were studied. The phase structure, microstructure and electrical properties were characterized in detail. The results show that the Curie temperature (TC) of PNN-PZT ceramics decreases from 324 °C to 44 °C while the piezoelectric coefficient (d33) changes from 43 pC/N to 1170 pC/N with PNN content from 0.12 to 0.64. Interesting phenomena were observed, which can provide useful information for practical applications of PNN-PZT ceramics.

The progress of next-generation electromechanical devices is substantially reliant upon achieving high electromechanical coupling performance in piezoelectric materials. Here, a local stress regulation strategy is introduced to significantly enhance the overall electromechanical response of lead-free piezoceramics. A remarkable large piezoelectric coefficient (d33) of ∼800 pC N−1 and longitudinal electromechanical coupling factor (k33) of 88% are obtained in (K,Na)NbO3 (KNN)-based textured piezoceramics. From both experimental examinations and theoretical simulation, including phase-field analyses, it is found that the improved piezoelectric performance primarily stems from the stress-induced elastic field aligned with the preferred crystallographic orientation, which constrains the domain size, resulting in nanoscale short-range ordered domain structures. Such structures facilitate the flexible rotation of electric dipoles within coexisting phases due to flattened free energy distribution, thereby leading to the exceptionally large piezoelectric response. This understanding provides valuable guidance for the design of novel lead-free piezoceramics with excellent piezoelectric performance.

001 > textured Pb(Ni1/3Nb2/3)O-3-PbZrO3-PbTiO3 (PNN-PZT) ceramics were prepared by templated grain growth (TGG) technique using 0.36PNN-xPZ-(0.64-x)PT ( x = 0.23, 0.25 and 0.27) powder matrix. Optimum template content was derived to achieve the best electromechanical properties of textured ceramics. The piezoelectric coefficient d(33) = 1165 pC/N, Curie temperature T-C = 197 C-degrees, longitudinal mode electrome-chanical coupling factor k(33) = 0.86 and a very large effective piezoelectric strain coefficient d(33) * = 2041 pm/V were simultaneously achieved at the morphotropic phase boundary (MPB) composition ( x = 0.25) with 3 vol.% BaTiO3 (BT) templates. Domain structures of textured ceramics were analyzed in detail to reveal the origin of these high piezoelectric and electromechanical properties. (c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Lead zirconate titanate (PZT) based piezoelectric ceramics are applied in ultrasonic transducers and multilayer actuators fields universally. Excellent piezoelectric properties of PZT-based ceramics of low sintering temperature are crucial for the applications of high-power motors and multilayer piezo-actuators due to the reduction of cost and energy consumption. In this paper, a ternary solid-solution ceramic system 0.05Pb(Mn1/3Sb2/3)O30.47PbZrO3-0.48PbTiO3 (PMS-PZT) was studied. A new complex additive composed of SiO2-Li2O3-CuO was doped into the PMS-PZT ceramics. The doping of CuO and Li2O3 was discovered to be able to lower the sintering temperature and remain electric properties efficiently, while the doping of SiO2 can decrease the grain size and increase the density. All ceramic samples were fabricated by solid-phase reaction method and sintered in the low temperature range from 800 degrees C to 1000 degrees C. The phase structure, morphology of natural surface and electrical properties of ceramics doped by 0.5 wt% additive were characterized. The 0.5 wt% additive doped PMS-PZT ceramics exhibit remarkable comprehensive piezoelectric properties sintered at 900 degrees C (d33 = 343 pC/N, Qm =1016, Tc = 328 degrees C, tans = 0.4 % (at 25 degrees C), epsilon r =1344, d33* = 490 pm/V). The sintering temperature 900 degrees C is significantly below the melting point of Ag (961.9 degrees C) and Cu (1083.4 degrees C), so the more cost-effective Cu internal electrodes and Ag rich Ag/Pd electrodes can be used to substitute the expensive Pd rich Ag/Pd internal electrodes in the production of devices composed of multilayer ceramic. The research of this work provides an important candidate additive for the applications of high-performance transducers and multilayer actuators with low cost.