In Situ X‐ray Diffraction of Biased Ferroelastic Switching in Tetragonal Lead‐free (1−x)Ba(Zr0.2Ti0.8)O3–x(Ba0.7Ca0.3)TiO3 Piezoelectrics

The effect of electric poling on the bipolar switching for tetragonal BZT–BCT materials is studied using large signal polarization and strain, small signal permittivity, and piezoelectric coefficient, as well as electric field–dependent in situ XRD experiments. Charge carrier agglomeration at domain and grain boundaries with increasing poling fields gives rise to an internal bias field that gradually biases domain switching behavior. The biased switching after electric poling is quantified during a bipolar measurement cycle from analysis of the electric and structural data. For a fresh sample the ferroelastic domain texture induced by a positive and negative electric measurement field is of the same magnitude. After poling, the induced ferroelastic domain texture is larger under a positive measurement field and smaller under a negative measurement field. A very large domain texture is achieved during poling, corresponding to 85% of the domains becoming aligned with their 002 pole in field direction. While the domain texture is significantly improved at higher poling fields, relaxation upon removal of the electric field appears independent of the poling history. This suggests a large extrinsic contribution to the macroscopic strain. It also facilitates the biased ferroelastic switching arising from the internal bias field developed during poling.     

Optimizing electrical poling for tetragonal,lead-free BZT–BCT piezoceramic alloys

The piezoelectric properties of tetragonal BZT–BCT materials have been shown to be improved by using the field cooling poling method. It is shown that the piezoelectric coefficient of tetragonal BZT–BCT materials increases with higher poling temperature, and the optimum poling temperature lies near the Curie temperatures for a broad range of compositions. It is also observed from in situ X-ray diffraction measurements with an applied electric field that the magnitude of domain alignment is enhanced with electrical poling at higher electric fields, whereas the remnant ferroelastic domain texture is not affected. Furthermore, these results show a direct correlation between the development of internal bias field, which is induced by the accumulation of defect charge carriers, and the enhanced piezoelectric coefficient. These observations suggest an important role played by the alignment of defect charge carriers in achieving optimum piezoelectric coefficient in lead-free piezoelectric ceramics.     

Morphotropic phase boundary and electrical properties of 1−x[Bi0.5Na0.5]TiO3 –xBa[Zr0.25Ti0.75]O3 lead-free piezoelectric ceramics

Lead-free solid solutions (1?x)Bi_0.5Na_0.5TiO₃ (BNT)–xBaZr_0.25Ti_0.75O₃ (BZT) (x=0, 0.01, 0.03, 0.05, and 0.07) were prepared by the solid state reaction method. X-ray diffraction (XRD) and Rietveld refinement analyses of 1?x(BNT)–x(BZT) solid solution ceramic were employed to study the structure of these systems. A morphotropic phase boundary (MPB) between rhombohedral and cubic structures occured at the composition x=0.05. Raman spectroscopy exhibited a splitting of the (TO₃) mode at x=0.05 and confirmed the presence of MPB region. Scanning electron microcopy (SEM) images showed a change in the grain shape with the increase of BZT into the BNT matrix lattice. The temperature dependent dielectric study showed a gradual increase in dielectric constant up to x=0.05 and then decrease with further increase in BZT content. Maximum coercive field, remanent polarization and high piezoelectric constant were observed at x=0.05. Both the structural and electrical properties show that the solid solution has an MPB around x=0.05.     

Preparation and characterization of Pb(Lu1/2Nb1/2)O3–Pb(In1/2Nb1/2)O3–PbTiO3 ternary ferroelectric ceramics with high phase transition temperatures

To explore new relaxor‐PbTiO₃ systems for high‐power and high‐temperature electromechanical applications, a ternary ferroelectric ceramic system of Pb(Lu_1/2Nb_1/2)O₃–Pb(In_1/2Nb_1/2)O₃–PbTiO₃ (PLN–PIN–PT) have been investigated. The phase structure, dielectric, piezoelectric, and ferroelectric properties of the as‐prepared PLN–PIN–PT ceramics near the morphotropic phase boundary (MPB) were characterized. A high rhombohedral‐tetragonal phase transition temperature T_R‐T of 165°C and a high Curie temperature T_C of 345°C, together with a good piezoelectric coefficient d₃₃ of 420 pC/N, were obtained in 0.38PLN–0.20PIN–0.42PT ceramics. Furthermore, for (0.8?x)PLN–0.2PIN–xPT ceramics, the temperature‐dependent piezoelectric coefficients, coercive fields and electric‐field‐induced strains were further studied. At 175°C, their coercive fields were found to be above 9.5 kV/cm, which is higher than that of PMN–PT and soft P5H ceramics at room temperature, indicating PLN–PIN–PT ceramics to be one of the promising candidates in piezoelectric applications under high‐driven fields. The results presented here could benefit the development of relaxor‐PbTiO₃ with enhanced phase transition temperatures and coercive fields.     

Domain Structure Evolutions During the Poling Process for [011]‐Oriented PMN–xPT Crystals Across the MPB Region

The poling effect on the [011]‐oriented (1?x)Pb(Mg_1/3Nb_2/3)O₃‐xPbTiO₃ (PMN–xPT) single crystals across the morphotropic phase boundary (MPB) was studied. The dielectric and piezoelectric properties were investigated as a function of the poling field. Domain structure evolutions during the poling process were recorded. In the unpoled PMN–xPT phase diagram, an apparent rhombohedral (R)‐tetragonal (T) phase boundary exists. With room‐temperature poling, the structure transformation sequence strongly depends on the composition. The crystal experiences a direct transition to the 2R/2T domain state in the rhombohedral or tetragonal phase field beyond the MPB region, whereas within the MPB zone it is hard to achieve the 2R/2T engineered configuration although the initial state is either rhombohedral or tetragonal as well. The piezoelectric responses of the MPB·PMN–xPTs are extraordinary weak (d₃₃ ~ 250 pC/N), in contrast to the [011]‐oriented multidomain PMN–xPTs with ultrahigh‐piezoelectric coefficient (d₃₃ > 1000 pC/N). We demonstrate that a slight composition variation near the MPB will significantly influence the domain evolution route and piezoelectricity for the [011]‐oriented PMN–xPT crystals. We also confirm the feasibility to realize the 2R/2T engineered domain configuration for the [011]‐oriented MPB crystals, which will extend the desired portion of the Bridgeman‐grown boules with optimal piezoelectric properties.     

Structure and properties of Bi(Zn½Ti½)O3-modified Pb(Zr,Ti)O3 piezo-/ferroelectric ceramics around the ternary morphotropic phase boundary

To develop high-performance piezo-/ferroelectric materials, Bi(Zn_½Ti_½)O₃–PbZrO₃–PbTiO₃ (BZT–PZ–PT) ternary solid solution with compositions around the morphotropic phase boundary (MPB) is synthesized by solid-state reaction. The crystal structure and electric properties are investigated systematically by X-ray powder diffraction (XRD), dielectric spectroscopy, and ferroelectric and piezoelectric measurements. On the basis of the results of the XRD, dielectric and ferroelectric measurements, the pseudo-binary phase diagram of the yBi(Zn_½Ti_½)O₃–(1 − y)[(1 − x)PbZrO₃–xPbTiO₃] system has been constructed for three series, namely, y = 0.05, 0.10, and 0.15. It is found that the introduction of BZT into the PZT system makes the paraelectric to ferroelectric phase transition more diffuse, brings the MPB to a lower PT content, and enlarges the MPB region. The best properties with an improved dielectric constant ε' = 1248, and a large remnant polarization P_r = 33 μC/cm², as well as a relatively high T_C = 286°C, and a high coercive field E_c = 23 kV/cm was achieved in the y = 0.15 series with MPB composition x = 0.425, making it a promising material for high-power piezoelectric applications.     

Enhanced structural,dielectric, ferroelectric,and piezoelectric properties of (1−x)Ba0.9Sr0.1TiO3–(x)Ba0.7Ca0.3TiO3 ceramics derived using mechano‐chemical activation technique

The effect of Ba_0.7Ca_0.3TiO₃ (BCT) substitution on the structural, dielectric, ferroelectric, and piezoelectric properties of mechano‐chemically synthesized lead‐free (1?x)Ba_0.9Sr_0.1TiO₃‐(x)Ba_0.7Ca_0.3TiO₃ (x=0.0, 0.10, 0.20, 0.35, and 0.50) ceramics have been investigated. XRD patterns confirms the formation of tetragonal phase with P4mm space group. The results indicate a strong influence of BCT substitution on the structural and electrical properties of Ba_0.9Sr_0.1TiO₃ (BST) ceramic. BST–BCT ceramic for x=0.35 have shown high dielectric constant ε_m~21 800, high remnant polarization P_r~10.16 μC/cm², large piezoelectric charge constant D₃₃~293 pC/N, large piezoelectric voltage constant g₃₃~5.80 mV·m/N, and highest dielectric breakdown strength E_bd~224 kV/cm among the five synthesized samples. The correlation between structural, dielectric, ferroelectric, and piezoelectric properties of the BST ceramic with increasing BCT content have been systematically described on the basis of domain wall motion and grain size effect.     

Resistivity Enhancement and Transport Mechanisms in (1 − x)BaTiO3–xBi(Zn1/2Ti1/2)O3 and (1 − x)SrTiO3–xBi(Zn1/2Ti1/2)O3

Ceramics of composition (1?x)BaTiO₃–xBi(Zn_1/2Ti_1/2)O₃ (BT‐BZT) were prepared by solid‐state synthesis; they have been shown to exhibit excellent properties suited for high‐temperature dielectric applications. The X‐ray diffraction data showed a single‐phase perovskite structure for all the compositions prepared (x ≤ 0.1 BZT). The compositions with less than 0.075 BZT exhibited tetragonal symmetry at room temperature and pseudo‐cubic symmetry above it. Most notably, a significant improvement in insulation properties was measured with the addition of BZT. Both low‐field AC impedance and high‐field direct DC measurements indicated an increase in resistivity of at least two orders of magnitude at 400°C with the addition of just 0.03 BZT (~10⁷ Ω‐cm) into the solid solution as compared to pure BT (~10⁵ Ω‐cm). This effect was also evident in dielectric loss data, which remained low at higher temperatures as the BZT content increased. In conjunction with band gap measurements, it was also concluded that the conduction mechanism transitioned from extrinsic for pure BT to intrinsic for 0.075 BZT suggesting a change in the fundamental defect equilibrium conditions. It was also shown that this improvement in insulation properties was not limited to BT‐BZT, but could also be observed in the paraelectric SrTiO₃–BZT system.     

The evolution of structure and electrical properties for BiFeO3–PbTiO3–Ba(Zr0.3Ti0.7)O3 high-temperature piezoceramics near the morphotropic phase boundary

The development of piezoceramics with high Curie temperature and high piezoelectrical performance has always been a long-cherished goal for many researchers. In this work, we have fabricated 0.55BiFeO₃-(0.45-x)PbTiO₃-xBa(Zr_0.3Ti_0.7)O₃ ternary ceramics near the morphotropic phase boundary (MPB) by conventional solid-state method. XRD patterns indicate that there is an evolution from the tetragonal (T) to pseudo-cubic (PC) phase with BZT content increasing from 0.125 to 0.225. Also, the slim P-E loop transforms into a saturated shape with the decrease of coercive field E_c. Piezoresponse force microscope (PFM) analysis reveals that when x (BZT content) increases, domain density increases. The optimum piezoelectric coefficient d₃₃ (~220 pC/N) is obtained at x = 0.175, while Curie temperature T_C and dielectric loss tanδ are 434 °C and 0.019, respectively. These results show that BF-PT-based piezoceramics are competitive candidates in future high-temperature applications of piezoelectric ceramics.     

Relaxor Characteristics of the Phase Transformation in (1 − x)BaTiO3–xBi(Zn1/2Ti1/2)O3 Perovskite Ceramics

The single‐phase solid solutions of the (1 ? x)BaTiO₃–(x)Bi(Zn_1/2Ti_1/2)O₃ (BT–BZT) where x = 0.02–0.15 were prepared to investigate dielectric properties. Crystal structure of samples was obtained by using an X‐ray diffraction technique and Raman spectroscopy. For compositions with x ≤ 0.08, the solid solutions exhibited clear tetragonal symmetry and transitioned to pseudocubic symmetry as the content of BZT increased. The dielectric response exhibited a sharp phase transition within the BT‐rich region and the composition 0.92BT–0.08BZT was characterized by the onset of relaxor characteristics. As the concentration of BZT increased, the phase transition exhibited broader and more diffuse behavior. The polarization as a function of electric field (P–E) of these solid solutions also exhibited the same trend. The BT‐rich compositions showed a normal ferroelectric P–E response with a decrease in loop area as the BZT content increased. The composition at x = 0.08 exhibited a pinched hysteresis loop and with further increase in BZT content, the P–E response was characterized by slim loops.     

Characterization of the High‐Temperature Ferroelectric (100−x−y)BiScO3–(x)Bi(Zr0.5Zn0.5)O3–(y)PbTiO3 Perovskite Ternary Solid Solution

Ternary compositions based on Bi(B′B″)O₃–PbTiO₃‐type compounds have been investigated for high‐temperature piezoelectric applications. Compositions in the ternary were chosen to be near the binary morphotropic phase boundary (MPB) composition of BiScO₃–PbTiO₃ (BS–PT). Ternary compositions in (100?x?y)BiScO₃–(x)Bi(Zr_0.5Zn_0.5)O₃–(y)PbTiO₃ [(100?x?y)BS–xBZZ–yPT] have been investigated with x ≤ 7.5. For compositions with x > 10, the Curie temperature (T_C) decreased below 400°C. Dielectric, piezoelectric, and electromechanical properties were characterized as a function of temperature, frequency, and electric field. Small additions of BZZ were shown to increase the electromechanical properties with only a small loss in T_C. The electromechanical properties were temperature stable up to the depoling temperature. The most promising composition exhibited a T_C of 430°C, piezoelectric coefficient (d₃₃) of 520 pC/N, and a planar coupling factor (k_p) of 0.45 that remained unchanged up to depoling temperature at 385°C.     

Electric field-induced changes in the ferroelastic behavior of (Na1/2Bi1/2)TiO3-BaTiO3

In this study, the macroscopic mechanical behavior was characterized for poled and unpoled polycrystalline (1?x)(Na_1/2Bi_1/2)TiO₃-xBaTiO₃ (NBT-xBT) for compositions across the morphotropic phase boundary (MPB). Due to a field-induced ferroelectric phase transformation, NBT-xBT compositions near the MPB (x?=?6–7?mol%) showed a significant decrease in the coercive stress for electrically poled samples. The apparent difference in mechanical behavior is suggested to be due to an irreversible electric-field-induced transformation to long-range ferroelectric order in the poled samples. The results indicate a significant difference in the critical stresses for the relaxor-ferroelectric transition and ferroelastic domain wall motion, which can have important effects on applications for lead-free ferroelectrics. To further illustrate this, a method was developed to electrically depole NBT-xBT at room temperature, resulting in an unpoled NBT-xBT material with long-range ferroelectric order. Mechanical testing revealed analogous macroscopic ferroelastic behavior to the poled samples, despite the lack of a piezoelectric response.     

Structural and electrical properties of ZnO-modified (1−x)Pb(Mg1/3Nb2/3)O3−xPbTiO3 ceramics with wide MPB regions

Ferro-/piezoelectric ceramics with high performances are generally found at the morphotropic phase boundary (MPB), where two or more different ferroelectric phases coexist. However, the MPB region is usually very narrow; for example, that of (1−x)Pb(Mg_1/3Nb_2/3)O₃−xPbTiO₃ (PMN-xPT) locates between x = 0.30−0.34. Herein, we report that ZnO-modified PMN-xPT polycrystalline ceramics have dramatically broadened MPB regions from x = 0.28, with rhombohedral and monoclinic coexisting phases, to x = 0.36, with tetragonal and monoclinic coexisting phases, as confirmed by powder X-ray diffraction and piezoresponse force microcopy measurements. The wide MPB region is attributed to lattice distortion caused by the substitution of Zn for Mg cations. As a result, the ceramics show composition insensitive electrical properties over wide composition ranges; for example, the piezoelectric coefficient (d₃₃) and electromechanical coupling factor (k_p) remain at near constant values of 450 pC/N and 0.5, respectively, in the range from x = 0.28−0.34. This work not only provides a robust and feasible method to broaden the MPB region but also offers some novel insights into promoting fundamental research on high-performance piezoelectric ceramics.     

Enhanced Multiferroic and Magnetocapacitive Properties of (1 − x)Ba0.7Ca0.3TiO3–xBiFeO3 Ceramics

The structures, Curie temperature, dielectric relaxor behaviors, ferroelectricity, ferromagnetism, and magnetocapacitance of the (1?x)Ba_0.70Ca_0.30TiO₃–xBiFeO₃ [(1?x)BCT–xBF, x = 0–0.90] solid solutions have been systematically investigated. The ceramics have coexisted tetragonal (T) and orthorhombic (O) phases when x ≤ 0.06, coexisted pseudocubic (PC) and O phases when x = 0.065, coexisted cubic and O phases when 0.07 ≤ x ≤ 0.12, PC phase when 0.21 ≤ x ≤ 0.42, coexisted T and rhombohedral (R) phases when 0.52 ≤ x ≤ 0.70, and R phase when x ≥ 0.75. Significantly, composition‐dependent microstructures and Curie temperature are observed, the average grain size increases from 1.9 μm for x = 0, reaches 12.0 μm for x = 0.67, and then decreases to 1.3 μm for x = 0.90. At room temperature, the ceramics with x = 0.42–0.70 show piezoelectric properties and multiferroic behaviors, characterized by the polarization‐electric field, polarization current intensity–electric field, and magnetization–magnetic field curves, the composition with x = 0.67 has maximum polarization, remnant polarization, maximum magnetization, and remnant magnetization of 15.0 μC/cm², 9.1 μC/cm², 0.33 emu/g, and 0.14 emu/g, respectively. In addition, the magnetocapacitance is evidenced by the increased relative dielectric constant with increasing the applied magnetic field (H). With ΔH = 8 kOe, the composition with x = 0.67 shows the largest values of (ε_r(H) ? ε_r(0))/ε_r(0) = 2.96% at room temperature. The structure–property relationship is discussed intensively.     

Correlation between structural,ferroelectric, piezoelectric and dielectric properties of Ba0.7Ca0.3TiO3-xBaTi0.8Zr0.2O3 (x = 0.45, 0.55) ceramics

We report on the correlation between structural, ferroelectric, piezoelectric and dielectric properties of the (1-x)Ba_0.7Ca_0.3TiO₃-xBaTi_0.8Zr_0.2O₃ (x?=?0.45, 0.55; abbreviated as 55BCT30 and 45BCT30) ceramics close to morphotropic phase boundary (MPB) region. The 55BCT30 and 45BCT30 ceramics were synthesized by the standard, high-temperature solid state ceramic method. X-ray diffraction (XRD) along with Rietveld refinement indicate that the 55BCT30 ceramics exhibit rhombohedral (R, space group R3m), orthorhombic (O, space group Amm2) and tetragonal (T, space group P4mm) phases while 45BCT30 ceramics exhibit only T and O phases. The temperature dependent Raman spectroscopy measurements confirm the structure and phase transformations observed from XRD. All the ceramics are chemically homogeneous and exhibit a dense microstructure with a grain size of 5–7?µm. The presence of polarization-electric field and strain-electric field hysteresis loops confirm the ferroelectric and piezoelectric nature of the ceramics. The polarization current density-electric field curves show the presence of two sharp peaks in opposite directions indicating the presence of two stable states with opposite polarity. Higher values of direct piezoelectric coefficient (d₃₃ ~?360 pC/N) were observed due to the existence of low energy barrier near MPB region and polymorphism. The 55BCT30 ceramics exhibit a higher value of electrostrictive coefficient (Q₃₃ ~?0.1339?m⁴/C²) compared to the well-known lead-based materials. The temperature dependent dielectric measurements indicate the O to T phase transition for 55BCT30 and 45BCT30. These ceramics exhibit a Curie temperature (T_c) of 380?K with a dielectric maximum of ~ 4500.     

Lead-free high performance Bi(Zn0.5Ti0.5)O3-modified BiFeO3-BaTiO3 piezoceramics

In this article, structure, dielectric, ferroelectric and piezoelectric properties of Bi rich Bi_1.05(Zn_0.5Ti_0.5)O₃-modified BiFeO₃-BaTiO₃ (BF-BT-xBZT) ceramics were investigated experimentally. Crystal structure, phase purity and microstructure were examined through X-ray diffractometry and scanning electron microscopy, respectively. The crystallographic results show the formation of single-phase solid solutions for all compositions except x?=?10?mol%. The BF-BT modification through BZT instigates variation in grain size, enhancement in Curie temperature (T_C) and field induced polarization and strain response. Large field induced strain of ～0.24% at low driving field along with a small hysteresis of ～38% was observed for 2?mol% BZT modified BF-BT ceramics. These investigated results signpost the potentiality of BF-BT-xBZT ceramics in high temperature piezoelectric device applications.     

Phase Transition and Ferroelectric Characteristics of Pb[(Mg1/3Nb2/3)1-xTix]O3 Ceramics Modified with La(Mg2/3Nb1/3)O3

The effects of 0–5 mol% addition of La(Mg_2/3Nb_1/3)O₃ (LMN) on the phase transition and ferroelectric behaviors of Pb[(Mg_1/3Nb_2/3)_1-xTi_x]O₃ (PMNT) ceramics with compositions near the morphotropic phase boundary (MPB) were studied. An evolution of structure from rhombohedral to tetragonal was found with increasing PbTiO₃ (PT) content across the MPB (at ∼32.5 mol% PT), and a coexistence of both rhombohedral and tetragonal phases was also found at the MPB. The dual-phase field extended toward the lower PT content side of the MPB, and, moreover, the rhombohedrality or tetragonality was reduced, especially for the compositions near the MPB, by the addition of La in PMNT. The ferroelectric transition was found to change from normal to diffuse as the La content increased and the compositions became more rhombohedral. In accordance with the structural evolution, the change of remanent polarization ( P _r) and coercive field ( E _c) also became gradually indistinct, and both P _r and E _c were reduced. For compositions near the MPB, both PMNT and La-modified PMNT had a similar electromechanical factor ( k _p) in a range around 0.55–0.60, but the mechanical quality factor ( Q _m) was significantly reduced for the La-modified PMNT. The piezoelectric coefficient ( d ₃₃), however, was largely improved with increasing La content in PMNT of compositions at MPB. A high value of d ₃₃∼ 815 pC/N was obtained for the 5-mol%-La-modified ceramics, but it was associated with a low value of Q _m.     

Crystal Structure and Ferroelectric Properties of (Bi0.5Na0.5)TiO3–Ba(Zr0.05Ti0.95)O3 Piezoelectric Ceramics

The crystal structure and ferroelectric properties of (1− x )(Bi_0.5Na_0.5)TiO₃– x Ba(Zr_0.05Ti_0.95)O₃ (BNBZT x, x ≤12%) lead-free piezoelectric ceramics were studied. The distance between the centers of cations and anions ( d _c–a) as well as the lattice parameters was carefully investigated by Rietveld refinement on X-ray diffraction patterns. It was found that the crystal phase was determined by the amount of Ba(Zr_0.05Ti_0.95)O₃ added, whereas the pure rhombohedral and tetragonal phases are observed in compositions containing x ≤4 and x ≥8%, respectively. A rhombohedral–tetragonal morphotropic phase boundary (MPB) was found at around BNBZT6, which showed a maximum and minimum d _c–a at its rhombohedral and tetragonal phases, respectively. According to the present study, the ferroelectric properties show a strong dependence on their crystal phases. For the single-phase compositions, the remanent polarization ( P _r) generally increased with the value of d _c–a while their coercive fields ( E _c) were determined by their lattice parameters. Nevertheless, the behavior in P _r and E _c for MPB compositions is related to not only the lattice parameter but also the composed phases.     

The Composition and Temperature‐Dependent Structure Evolution and Large Strain Response in (1−x)(Bi0.5Na0.5)TiO3−xBa(Al0.5Ta0.5)O3 Ceramics

The (1?x) (Bi_0.5Na_0.5)TiO₃?xBa(Al_0.5Ta_0.5)O₃((1?x)BNT‐xBAT) lead‐free piezoceramics was fabricated using a conventional solid‐state reaction method. The temperature and composition‐dependent strain behavior, dielectric, ferroelectric (FE), piezoelectric, and pyroelectric properties have been systematically investigated to develop lead‐free piezoelectric materials with large strain response for actuator application. As the BAT content increased, the FE order is disrupted resulting in a degradation of the remanent polarization, coercive field, and the depolarization temperature (T_d). A large strain of 0.36% with normalized strain d₃₃* = 448pm/V was obtained for the optimum composition x = 0.045 at room temperature. The bipolar and unipolar strains for the compositions x = 0.035 and x = 0.04 reach almost identical maximum values when the temperature is in the vicinity of their respective depolarization temperature (T_d). The Raman‐spectra analysis, macroscopic properties, thermal depolarization results, and temperature‐dependent relationships of both polarization and strain demonstrated that the origin of the large strain response for this investigated system is attributed to a field‐induced relaxor to FE phase transformation.