Simultaneously enhanced piezoelectric response and piezoelectric voltage coefficient in textured KNN‐based ceramics

<001> ‐textured 0.99(K_0.49Na_0.49Li_0.02)(Nb_0.97‐xSb_0.03Ta_x)O₃‐0.01CaZrO₃ [abbreviated as 0.99KNLN_0.97‐xST_x‐0.01CZ, x = 0.03, 0.07, 0.10, 0.15, 0.20, 0.25] ceramics were prepared by templated grain growth (TGG) method and a two‐step sintering process. Giant longitudinal piezoelectric coefficient d₃₃ (391 pC/N) and piezoelectric strain coefficient d₃₃* (630 pm/V under an AC E‐field of 20 kV/cm) can be obtained in the textured ceramics with x = 0.25. All textured ceramics display superior k_p (>54%) and g₃₃ (>23 × 10^?3 Vm/N) which are in an order of magnitude with PZT ceramics. The maximum value of k_p (~63.3%) obtained in textured ceramics with x = 0.15 is higher than that of famous textured LF4 ceramics. Excellent comprehensive properties suggest that <001> ‐textured 0.99KNLN_0.97‐xST_x‐0.01CZ ceramics are promising candidates in the field of lead‐free piezoelectric materials.     

Achieving large piezoelectric response and ultrahigh electrostriction in [001] textured BiScO3-PbTiO3 high-temperature piezoelectric ceramics

[001] textured 0.40BiScO₃-0.60PbTiO₃-0.125 mol%Nb⁵⁺ (BS-60PT-0.125Nb) high-temperature piezoelectric ceramics were synthesized using templated grain growth process. A high texture degree F₀₀₁ of 99% was obtained using 2 vol% BaTiO₃ (BT) templates. The piezoelectric charge constant d₃₃ and the unipolar strain under 40 kV cm⁻¹ at room temperature for the textured ceramics are 646 pC N⁻¹ and 0.36%, respectively, which is over two times as those for untextured ceramics (∼243 pC N⁻¹ and 0.17%). The electrostriction Q₃₃ value of the textured sample remarkably increased from 0.034 m⁴ C⁻² to 0.068 m⁴ C⁻² under 30 kV cm⁻¹, showing a twice higher than untextured. Compared with random ceramics, the improvement piezoelectric response of the textured ceramics is primarily attributed to the increase of the dielectric constant ε_r and electrostriction coefficient Q₃₃ along [001] orientation, which is originating from the anisotropy of piezoelectricity. The BS-60PT-0.125Nb textured ceramics have large piezoelectric response and ultrahigh electrostriction with high temperature stability (high depolarization temperature T_d of ∼360°C and high Curie temperature T_c of 421°C), showing great potential for the piezoelectric applications at high temperatures.     

Ultra-high-temperature piezoelectric responses and ultra-high thermal stability of piezoelectricity in ceramic PbZr0.54Ti0.46O3

To date, most piezoceramics with a high piezoelectric coefficient (d₃₃ > 500 pC/N) and a high Curie temperature (T_C around 400°C) are BiScO₃-PbTiO₃-based (BS-PT-based) systems, containing the rare-earth element Sc, whose high cost hinders mass production. We investigated the effect of Nd-doping on the morphotropic phase boundary and synthesized low-cost Nd-doped PbZr_0.54Ti_0.46O₃ (PZT) piezoceramics, achieving high piezoelectric performance. At room temperature, the piezoelectric coefficient d₃₃ reached 550 pC/N with a T_C = 375°C and this changed by only 3.6% over a broad temperature range (30–260°C). The d₃₃ value reached an ultra-high value of 941 pC/N at 345°C, which is higher than that of a BS-PT-based ceramic (810 pC/N at 350°C). The developed PZT ceramic material has a superior electrostrictive strain of 0.45% at 40 kV/cm, and a room temperature piezoelectric coefficient d₃₃* of 1312 pm/V at 20 kV/cm. Our research provides a new paradigm for designing piezoceramics that can be used over a wide temperature range.     

3D printing orientation controlled PMN-PT piezoelectric ceramics

Piezoelectric textured ceramics have drawn increasing research and industry interests by balancing the production cost and material performances. A new approach to realize the texture in piezoelectric ceramics is developed based on 3D printing stereolithography (SL) technique and successfully applied in the preparation of < 001 > -textured 0.71(Sm_0.01Pb_0.985)(Mg_1/3Nb_2/3)O₃-0.29(Sm_0.01Pb_0.985)TiO₃ (1 %Sm-PMN-29PT) ceramics in this work. As a critical process in texture ceramic fabrication, the alignment of BaTiO₃ templates along the horizontal direction is achieved by the shear force produced from the relative motion between the resin container and the blade during SL. The textured ceramics with obvious grain orientation features are successfully obtained. The enhanced piezoelectric properties of d₃₃ ≈ 652 pC N^?1 and d₃₃* ≈ 800 pm V^?1 are achieved in the 3D printed textured ceramic, which are about 60 % and 40 %, respectively, higher than their non-textured counterparts. Moreover, the textured sample shows a significant improvement on thermal stability of d₃₃*_T, which varies by less than ± 6 % from RT to 110 °C. Furthermore, the introduction of 3D printing into the synthesis of textured piezoelectric ceramics shows great advantages over the traditional tape-casting method. This work is expected to provide a promising way for the future design of textured piezoelectric functional materials.     

Achieving both high electromechanical properties and temperature stability in textured PMN-PT ceramics

Textured piezoelectric ceramics, such as textured Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PMN-PT) ceramics, have attracted considerable attention from both academia and industry, as they possess crystal-like piezoelectric properties, high composition homogeneity, and low manufacturing cost. However, the main difficulty with the textured piezoelectric ceramics is the presence of BaTiO₃ (BT) templates, which greatly reduces their piezoelectricity and phase transition temperature. Thus, it is highly recommended to fabricate textured piezoelectric ceramics using as few templates as possible. Here, we successfully fabricated high-quality <001>-textured PMN-28PT ceramics (texturing degree of 99%) by using an extremely small amount of BT templates (1 vol.%) with the help of CuO/B₂O₃ sintering aids. The textured PMN-28PT ceramic exhibits 80% piezoelectric coefficient (d₃₃ ∼ 1200 pC/N), 96% electromechanical coefficient (k₃₃ ∼ 88%) and the same temperature stability (T_rt ∼ 100, T_c ∼ 150°C) when compared to its single crystal counterpart. In addition, by using an alternating current electric field poling (AC-poling), the piezoelectric coefficient d₃₃ and dielectric permittivity ε₃₃ of the textured PMN-28PT ceramics were further enhanced around 5–8%. It is believed that the advantages of high electromechanical properties, low cost, and easy mass production of textured PMN-28PT ceramic will make it a promising candidate for advanced electromechanical devices.     

Piezoelectric Ceramics for Use in Multilayer Actuators and Energy Harvesters

Microstructural and piezoelectric properties of 0.72Pb(Zr_1?xTi_x)–0.28Pb(Zn_0.4Ni_0.6)_1/3Nb_2/3O₃ (PZ_1?xT_x‐PZNN) ceramics with 0.50 ≤  x ≤ 0.55 were investigated for evaluating the possibility of their use in multilayer actuators and energy harvesters, which demand a large piezoelectric strain constant (d₃₃) and a small dielectric constant (ε^T₃₃/ε_o). The PZ_0.47T_0.53‐PZNN ceramic with a morphotropic phase boundary (MPB) composition showed large d₃₃ and ε^T₃₃/ε_o values, making it unsuitable for use in multilayer actuators and energy harvesters. However, the PZ_0.48T_0.52‐PZNN ceramic with a rhombohedral structure showed a small ε^T₃₃/ε_o value of 1605, yet maintained a large d₃₃ of 550 pC/N. Thermal stimulation did not have any significant effect on the piezoelectric properties of this specimen, except for a slight increase in the ε^T₃₃/ε_o value upon heating the specimen at 150°C for 4 h. In an effort to reduce the sintering temperature, CuO was used as an additive for the ceramic. As a result, the CuO‐added PZ_0.48T_0.52‐PZNN ceramic was well sintered at 900°C. In particular, the 1.0 mol% CuO‐added PZ_0.48T_0.52‐PZNN ceramic exhibited a large d₃₃ value of 554 pC/N and a small ε^T₃₃/ε_o value of 1620, making it highly suitable for use in multilayer actuators and energy harvesters.     

Low sintering temperature for lead-free BiFeO3-BaTiO3 ceramics with high piezoelectric performance

Through modification of the heat-treatment process using a higher heating rate and a lower binder burnout temperature, the piezoelectric performance of water-quenched 0.67Bi_1.05FeO₃-0.33BaTiO₃ (BF33BT) lead-free piezoelectric ceramics was improved. The observed physical properties of BF33BT ceramics were very sensitive to the process temperatures. The sintering temperature (T_S) was changed within a narrow temperature range, and its effects were investigated. The largest rhombohedral distortion (90°-α_R = 0.14°) and tetragonality (c_T/a_T = 1.022) were observed for the ceramic sintered at 980°C, and its Curie temperature was 476°C. This ceramic showed good piezoelectric properties and large grains; the piezoelectric sensor charge coefficient (d₃₃) was 352 pC/N, and the piezoelectric actuator charge coefficient () was 270 pm/V. The high piezoelectric performance and low T_S of BF33BT ceramics indicate their potential as new low-cost eco-friendly lead-free piezoceramics.     

Enhanced piezoelectric properties in BF-BT based lead-free ferroelectric ceramics for high-temperature devices

Due to the high Curie temperature (T_C), BiFeO₃–BaTiO₃ (BF-BT) ceramics have been broadly investigated in high-temperature piezoelectric devices. The piezoelectric constant is one of the most significant factors in determining the sensitivity and reliability of piezoelectric functional components. However, the poor piezoelectric constant (d₃₃) of BF-BT ceramic has prevented the practical application of the material. In this work, we innovatively introduce the 0.93Bi_0.5Na_0.5TiO₃-0.07BaTiO₃ (0.93NBT-0.07BT) component to 0.7BF-0.3BT ceramic, to build a morphotropic phase boundary (MPB) for enhancing d₃₃. The XRD analysis shows that the (0.7BF-0.3BT)-x(0.93NBT-0.07BT) ceramics are still in the MPB region with R–PC phases coexistence, and exhibits a homogeneous solid solution. Moreover, the introduction of 0.93NBT-0.07BT ceramic suppresses the generation of defects and facilitates grain growth, thus enhancing piezoelectric property. In consequence, an optimum piezoelectricity d₃₃ = 213 pC/N along with T_c～450 °C was obtained in (0.7BF-0.3BT)-0.01(0.93NBT-0.07BT). This research provides a new idea for the application of BF-BT ceramics in high-temperature piezoelectric devices.     

Investigation of the piezoelectric and anti-reduction properties of (Ba,Ca) (Ti,Sn, Hf) textured ceramics prepared under low oxygen partial pressure conditions at low sintering temperatures

Multilayer piezoelectric ceramics must be sintered in a reducing atmosphere, preventing oxidation of the inner base metal. Plate-like textured (Ba, Ca)(Ti, Sn, Hf)O₃ ceramics with a <001> preferred orientation were successfully developed at a low oxygen partial pressure (PO₂:10^?8 atm) using a BaTiO₃ (BT) template with sintering temperatures < 1300 °C, which is beneficial for multilayer applications using base metal co-firing with ceramics. When adding the 3 wt% BT template, the proposed samples had a Lottgering factor of 84 %, piezoelectric coefficients d₃₃ = 324 pC/N, -d₃₁ = 122 (pC/N), and Q_m = 452, and the strain values increased from 0.07 % for the randomly oriented ceramics to 0.115 % at 20 kV/cm for the textured ceramics, confirming that the texturing behavior assisted the grain growth and improved both the soft and hard behaviors and insulation resistance of the proposed lead-free ceramics. These findings make a significant contribution to the production of high-power piezoelectric components.     

Low‐temperature sintering and enhanced piezoelectric properties of random and textured PIN–PMN–PT ceramics with Li2CO3

Low‐temperature sintered random and textured 36PIN–30PMN–34PT piezoelectric ceramics were successfully synthesized at a temperature as low as 950°C using Li₂CO₃ as sintering aids. The effects of Li₂CO₃ addition on microstructure, dielectric, ferroelectric, and piezoelectric properties in 36PIN–30PMN–34PT ternary system were systematically investigated. The results showed that the grain size of the specimens increased with the addition of sintering aids. The optimum properties for the random samples were obtained at 0.5 wt% Li₂CO₃ addition, with piezoelectric constant d₃₃ of 450 pC/N, planar electromechanical coupling coefficient k_p of 49%, peak permittivity ε_max of 25 612, remanent polarization P_r of 36.3 μC/cm². Moreover, the low‐temperature‐sintered textured samples at 0.5 wt% Li₂CO₃ addition exhibited a higher piezoelectric constant d₃₃ of 560 pC/N. These results indicated that the low‐temperature‐sintered 36PIN–30PMN–34PT piezoelectric ceramics were very promising candidates for the multilayer piezoelectric applications.     

Structural and Piezoelectric Properties of (1−x)Pb(Zr1−yTiy)O3–xPb(Zn0.4Ni0.6)1/3Nb2/3O3 Ceramics Near Triple Point

The crystal structure and piezoelectric properties of (1?x)Pb(Zr_1?yTi_y)O₃‐xPb(Zn_0.4Ni_0.6)_1/3Nb_2/3O₃ [(1?x)PZ_1?yT_y‐xPZNN] ceramics were investigated. The 0.665PZ_0.45T_0.55‐0.335PZNN ceramic has the triple point composition, where the rhombohedral, pseudocubic, and tetragonal structures coexist. Maximum d₃₃ and k_p values of 770 pC/N and 0.69, respectively, were observed from this specimen; it also exhibited a large ε^T₃₃/ε_o value of 3250. Although the maximum d₃₃ value was obtained from the triple point composition specimen, its g₃₃ and d₃₃ × g₃₃ values were relatively small because of its large ε^T₃₃/ε_o value. However, the 0.665PZ_0.46T_0.54‐0.335PZNN ceramic, which has a rhombohedral structure, exhibited a large g₃₃ value of 43 × 10^?3 Vm/N and a d₃₃ × g₃₃ value of 27 000 × 10^?15 m²/N. Therefore, this ceramic is a good candidate for multilayer actuators and piezoelectric energy harvesters.     

Enhanced piezoresponse and electric field induced relaxor-ferroelectric phase transition in NBT-0.06BT ceramic prepared from hydrothermally synthesized nanoparticles

0.94Na_0.5Bi_0.5TiO₃-0.06BaTiO₃ (NBT-0.06BT) nanoparticles were synthesized by hydrothermal method and subsequently used to prepare NBT-0.06BT ceramics. After poling at the electric field of 3.5 kV/mm, the piezoelectric coefficient (d₃₃) and electromechanical coupling factor (κ_p) reached 171 pC/N and 0.31, respectively. The NBT-0.06BT ceramics also exhibited a large remanent polarization of 46.10 μC/cm² and electric field induced strain of 0.243% at 8 kV/mm corresponding to normalized strain d₃₃^*=303 pm/V (S_max/E_max). The effects of polarization on crystalline phase, microstructures, dielectric properties and domain structures were investigated to reveal the origin of enhanced piezoresponse and electric field induced strain in as-prepared NBT-0.06BT ceramics. It can be observed that the tetragonal phase in NBT-0.06BT ceramics was enhanced and polar nanoregions were transformed into tweed-like structures and some lamellar domains after E-field poling. The dielectric response of NBT-0.06BT ceramics also exhibited an electric-field-induced relaxor-to-ferroelectric phase transition.     

Crystallographic texture and phase structure induced excellent piezoelectric performance in KNN-based ceramics

It is difficult to maintain strong piezoelectric properties over a wide temperature range in (K,Na)NbO₃ (KNN)-based ceramics owing to the polymorphic phase boundary (PPB). Here, we propose advantageously utilizing the synergistic effect of crystal orientation and phase structure to address this issue. The 〈0 0 1〉_pc textured (1 − x)(K_0.48Na_0.52)(Nb_0.96Sb_0.04)O₃–x(Bi_0.5Ag_0.5)ZrO₃ (KNNS–xBAZ) ceramics with different phase structures were synthesized via the templated grain growth method. A high piezoelectric coefficient (d₃₃) of 505 ± 25 pC/N, an electric field-induced strain of 0.21%, and a superior temperature stability (d₃₃ exhibited a high retention of ≥78% at the temperature up to 200°C; strain maintained within 5.7% change over a temperature range of 30–150°C) were simultaneously achieved in textured KNNS–0.03BAZ ceramics. The flattened Gibbs free energy induced by the R–O–T multiphase coexistence, the strong anisotropy of crystals, and the abundant nanodomains contributed to the enhanced piezoelectric properties. The contribution of the strong anisotropy of crystals in 〈0 0 1〉_pc textured ceramics compensates for the deterioration of the piezoelectric properties caused by the phase structure deviation from the PPB with increasing temperature, which benefits the superior temperature stability of the textured KNNS–0.03BAZ ceramics. The previous merits prove that utilizing the synergistic effect of crystal orientation and phase structure is an effective strategy to boost the piezoelectricity and their temperature stability of KNN-based ceramics.     

Sintering Behavior,Properties, and Applications of Co‐Fired Piezoelectric/Low Temperature Co‐Fired Ceramic (PZT‐SKN/LTCC) Multilayer Ceramics

Materials and processing conditions have been developed allowing co‐firing of fluxed PZT‐SKN materials with commercial low temperature co‐fired ceramic (LTCC) tapes. Previously, Pb(Zr_0.53, Ti_0.47)O₃–Sr(K_0.25, Nb_0.75)O₃ (PZT‐SKN) ceramics fluxed with 1 wt% LiBiO₂ and 1 wt% CuO addition were shown to sinter to high density at 900°C for 1 h, with a large d₃₃ piezoelectric coefficient of ~415 pm/V. Currently, the master sintering curve (MSC) approach has been used to study the densification behaviors of fluxed PZT‐SKN and LTCC tapes. Different sintering mechanisms for fluxed PZT‐SKN ceramics and LTCC materials are confirmed by analyzing the apparent activation energy (Q_a). Using knowledge gained from MSC results, an optimized sintering profile was developed. Multilayer PZT‐SKN/HL2000 (HeraLock^? Tape, Heraeus) stacks co‐fired at 900°C for 0.5 h maintain large piezoelectric coefficient (high field d₃₃ > 340 pm/V). EDS analysis reveal limited interdiffusion of Pb from PZT‐SKN layers in LTCC and the appearance of Al, Ca, and Si in the PZT‐SKN near the PZT‐SKN/LTCC interface. Further, elemental interdiffusion was not detected at the center of piezoelectric layer in PZT‐SKN/LTCC multilayer ceramics and no subsequent reduction in piezoelectric coefficient d₃₃ was observed. Finally, a piezoelectric microbalance with mass sensitivity of 150 kHz/mg was fabricated using the materials and methods developed.     

Large electric‐field‐induced strain and enhanced piezoelectric constant in CuO‐modified BiFeO3‐BaTiO3 ceramics

In this work, we fabricated the (1‐x)BiFeO₃‐xBaTiO₃+y‰ mol CuO ceramics by the modified thermal quenching technique. The pure perovskite phase was formed and a morphotropic phase boundary (MPB) was observed in the ceramics with x = 0.30‐0.33. The addition of CuO can significantly enhance the density of the BiFeO₃‐BaTiO₃ material. Importantly, an enhanced piezoelectric constant (d₃₃=165 pC/N), a large electric‐field‐induced strain (?S = 0.54%: peak to peak strain) and a large piezoelectric actuator constant (d₃₃*=449 pm/V) together with a high Curie temperature (T_C) of 503°C were observed in the ceramics with x = 0.30 and y = 5. As a result, the enhanced piezoelectricity and large electric‐field‐induced strain could significantly stimulate further researches in BFO‐based ceramics.     

Dielectric,Ferroelectric, and Piezoelectric Properties of BiFeO3–BaTiO3 Ceramics

Perovskite solid solution ceramics of (1 ? x)BiFeO₃–xBaTiO₃ (1 ? x)BF–xBT, 0.2 ≤ x ≤ 0.45) with high electrical resistivity were prepared by solid‐state reaction method. Actual ferroelectric hysteresis loops and temperature dependence of dielectric constant of the ceramics were obtained. Ceramics of 0.7BF–0.3BT with small rhombohedral distortion show highest remnant polarization (P_r = 26.0 μC/cm²) and piezoelectric coefficient (d₃₃ = 134 pC/N). Compositions with pseudo‐cubic symmetry (intermediate phases) show relaxor‐like dielectric anomaly. The values of P_r and d₃₃ decrease with increasing BT content, from 24.8 μC/cm² and 104 pC/N for 0.65BF–0.35BT to 8.2 μC/cm² and 5 pC/N for 0.55BF–0.45BT.     

Microstructure and electrical properties of Er-doped 0.67 Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 ceramics with BaTiO3 templates

In this study, [001]-oriented Er-doped 0.67 Pb(Mg_1/3Nb_2/3)O₃-0.33PbTiO₃ (0.67PMN-0.33 PT) textured ceramics with different BaTiO₃ (BT) template concentrations were explored. The samples were prepared by tape-casting. Er³⁺ was added to modify the electrical properties of the polycrystalline ceramics, and the BT template was used to improve the texture of polycrystalline ceramics. The 0.67PMN-0.33 PT textured ceramics contained coexisting rhombohedral and tetragonal phases. The ceramics became increasingly textured as the sintering temperature increased up to 1250 °C. The piezoelectric coefficient of 0.67PMN-0.33 PT with 5 wt% BT was 634 pC/N, which is 1.2 times than that of randomly oriented 0.67PMN-0.33 PT. The strain of the ceramic with 5 wt% BT increased by 12.5% relative to a random control specimen. Analysis of the electrical properties and microstructure suggested that the enhancement of the piezoelectric coefficient and strain may be caused by the addition of Er³⁺ and the BT template. First, the directional growth of grains along the template affected the change-of-phase distribution of the system and formed a more adaptive phase. Second, Er³⁺ was substitutionally doped on the A-site of the perovskite to form local heterostructures. Finally, the relaxation components of the templates and Er³⁺ changed in the solid solution with the matrix. The solid solution of the BT templates and Er-doped-matrix powder changed the relaxation degree, which affected the interactions at the polar nanoregions and increased the piezoelectric coefficient of the ceramics.     

Thermally stable high strain and piezoelectric characteristics of (Li,Na, K)(Nb,Sb)O3-CaZrO3 ceramics for piezo actuators

The 0.97(Na_0.5K_0.5)(Nb_1−xSb_x)O₃-0.03CaZrO₃ ceramic with x = 0.09 exhibits a high d₃₃ of 518 pC/N and a strain of 0.13% at 4.0 kV/mm owing to its orthorhombic-pseudocubic polymorphic phase boundary (PPB) structure. However, these values decreased considerably above 90°C owing to its low Curie temperature (T_C), indicating that its thermal stability is not sufficient for practical applications. Li₂O was added to the specimen with x = 0.11 to improve its thermal stability of the strain and d₃₃ by increasing the T_C without degrading the actual d₃₃ and strain values. The 0.97(Li_0.04Na_0.46K_0.5)(Nb_0.89Sb_0.11)O₃-0.03CaZrO₃ ceramic, having an orthorhombic-tetragonal PPB structure, exhibits a d₃₃ of 502 pC/N and a strain of 0.16%. This large strain was maintained up to 150°C and the d₃₃ slightly decreased to 475 pC/N at 130°C. Therefore, this lead-free ceramic displays excellent piezoelectric characteristics with improved thermal stability, indicating that it can be applied to piezoelectric actuators.     

Enhancement of piezoelectric properties of BF–BT ceramics by using ZrO2 powder bed during the sintering process

ZrO₂ powders of various particle sizes (0.15, 0.7, 500 µm) were used to simulate loose powder bed sintering to prepare BF–BT piezoelectric ceramics. The phase structure, dielectric properties, ferroelectric properties, and piezoelectric properties were compared with the samples sintered by the conventional powder bed method (i.e., powder of the same composition as the sample). Results showed that the use of loose ZrO₂ powder bed could improve the heat conduction rate and the sintering quality of bulk BF–BT piezoelectric ceramics. The XPS results showed that the samples sintered with 500 µm ZrO₂ powder beds had the lowest concentration of Fe²⁺, exhibited the largest piezoelectric coefficients (d₃₃ = 201 pC/N). In contrast, the sample sintered with a conventional powder bed under the same sintering conditions had a piezoelectric coefficient d₃₃ of 156 pC/N.     

High Electric‐Induced Strain and Temperature‐Dependent Piezoelectric Properties of 0.75BF–0.25BZT Lead‐Free Ceramics

0.75BiFeO₃–0.25Ba(Zr_xTi_1?x) + 0.6 wt% MnO₂ (0.75BF–0.25BZT) ceramics with Mn addition were prepared by the solid‐state reaction method. The high‐field strain and high‐temperature piezoelectric properties of 0.75BF–0.25BZT ceramics were studied. Introduction of Zr in the solid solutions decreased the Curie temperature slightly, and improved the dielectric and piezoelectric properties obviously. The piezoelectric properties of 0.75BZT–0.25BT ceramics reached the maximum at Zr content of 10 mol%. The Curie temperature T_c, dielectric constant ε and loss tanδ (1 kHz), piezoelectric constant d₃₃, and planner electromechanical coupling factor k_p of 0.75BF–0.25BZT ceramics with 10 mol% Zr were 456°C, 650, 5%, 138 pC/N, and 0.30, respectively. The high‐field bipolar and unipolar strain under an electric field of 100 kV/cm reached up to 0.55% and 0.265%, respectively, which were comparable to those of BiScO₃–PbTiO₃ and “soft” PZT‐based ceramics. The typical “butterfly”‐shaped bipolar strain and frequency‐dependent peak‐to‐peak strain indicated that the large high‐field‐induced strain may be due to non‐180° domain switching. Rayleigh analysis reflected that the improved piezoelectric properties resulted from the enhanced extrinsic contribution by Zr doping. The unipolar strain of 0.75BF‐0.25BZT ceramics with 10 mol% Zr was almost linear from RT to 200°C. These results indicated that 0.75BF–0.25BZT ceramics were promising candidates for high‐temperature and lead‐free piezoelectric actuators.