Large Electrostrain Research Articles

Giant electro-induced strain in lead-free relaxor ferroelectrics via defect engineering

Lead-free relaxor ferroelectric (RFE) ceramics find application in a broad range of technological devices due to their large electrostrain. But few lead-free ceramics show electrostrain values of more than 1 %. Here, an extraordinary strategy to obtain giant electrostrain by manipulating defect dipoles in (Bi, Na)TiO3-BaTiO3-based RFE ceramics is developed, achieving a high electro-induced strain value of 1.68 %, with a corresponding effective piezoelectric coefficient (d*33) of 1965 pm/V. Furthermore, the effect of defect dipoles on RFE ceramics is discussed. The defects are pinned after poling, forming defect dipoles polarization (Pd) oriented along or close to the poling direction. Pd significantly promotes the transformation of polar nano regions to ferroelectric domains during strain-electric field (S-E) cycles, resulting in ultra-high electrostrain. This work proposes a detailed mechanism considering defect dipoles coupling in RFE ceramics and provides a promising paradigm for achieving high electrostrain, which could be applied in designing a wide range of functional ceramics.

Lead free 0.9Na1/2Bi1/2TiO3–0.1BaZr0.2Ti0.8O3 thin film with large piezoelectric electrostrain

A sodium bismuth titanate-based thin film is widely investigated lead-free piezoelectrics with potential applications for modern micro-devices such as PiezoMEMS. In this work, a 0.9Na1/2Bi1/2TiO3–0.1BaZr0.2Ti0.8O3 thin film was deposited on a Pt/Ti/SiO2/Si (001) substrate by the sol–gel spin coating method. The deposited piezoelectric film shows low dielectric loss and high remnant polarization. The measured ferroelectricity loop showed a coercive field of 110 kV/cm and a saturation polarization of 46.83 μC/cm2. The piezoelectric response of this thin film does not decrease from room temperature to around 100 °C. The fabricated piezoelectric device with bottom and top electrodes showed a large macro-scale strain value of ∼4% under the DC (30 V) and AC voltages (f = 800 kHz, Vpp = 10 V).

Contrasting phenomena of quenching-induced piezoelectric performance in (0.4Na1/2Bi1/2TiO3-0.6BiFeO3)-xBaTiO3 ferroelectrics and relaxors

Na1/2Bi1/2TiO3 (NBT)-based materials are promising lead-free alternatives due to their large electrostrain and stable mechanical quality factor. Nonetheless, the relatively low depolarization temperature (Td) impairs its practical application. Recently, quenching from sintering temperature was adopted to increase Td of NBT-based ceramics. However, the origin of the quenching-induced increase in Td is still debated. In this study, quenching effects in (1-x)(0.4Na1/2Bi1/2TiO3-0.6BiFeO3)-xBaTiO3 ceramics are investigated. With increasing BaTiO3 content, this system transforms from ferroelectric to relaxor state at room temperature, with a criticality at x = 0.07, which exhibits R3c and P4bm coexisted phases. Ferroelectric and relaxor compositions exhibit different responses upon quenching. Upon quenching the ferroelectrics, Td increases from 420 to 580 °C for x = 0.04, but d33 is majorly unaltered. However, upon quenching the relaxors, Td increases marginally, while d33 increases from 62 to 97 pC/N. The correlation between the structural evolution and electrical responses upon quenching ferroelectric and relaxor compositions is explored.

Deciphering the phase transition-induced ultrahigh piezoresponse in (K,Na)NbO3-based piezoceramics

Here, we introduce phase change mechanisms in lead-free piezoceramics as a strategy to utilize attendant volume change for harvesting large electrostrain. In the newly developed (K,Na)NbO3 solid-solution at the polymorphic phase boundary we combine atomic mapping of the local polar vector with in situ synchrotron X-ray diffraction and density functional theory to uncover the phase change and interpret its underlying nature. We demonstrate that an electric field-induced phase transition between orthorhombic and tetragonal phases triggers a dramatic volume change and contributes to a huge effective piezoelectric coefficient of 1250 pm V−1 along specific crystallographic directions. The existence of the phase transition is validated by a significant volume change evidenced by the simultaneous recording of macroscopic longitudinal and transverse strain. The principle of using phase transition to promote electrostrain provides broader design flexibility in the development of high-performance piezoelectric materials and opens the door for the discovery of high-performance future functional oxides.

Ultra-slim electrostrains with superior temperature-stability in lead-free sodium niobate-based ferroelectric perovskite

Large electrostrains with high temperature stability and low hysteresis are essential for applications in high-precision actuator devices. However, achieving simultaneously all three of the aforementioned features in ferroelectric ceramics remains a considerable challenge. In this work, we firstly report a high unipolar electrostrain (0.12% at 60 kV/cm) in (1–x)NaNbO3-x[(Ba0.85Ca0.15)(Zr0.1Ti0.9)O3] (NN-xBCZT) ferroelectric polycrystalline ceramics with excellent thermal stability (variation less than 10% in the temperature range of 30–160 °C) and ultra-low hysteresis (<6%). Secondly, the high-field electrostrain response is dominated by the intrinsic electrostrictive effect, which may account for more than 80% of the electrostrain. Furthermore, due to the thermal stability of the polarization in the pure tetragonal phase, the large electrostrain demonstrates extraordinarily high stability from room temperature to 140 °C. Finally, in-situ piezoelectric force microscopy reveals ultra-highly stable domain structures, which also guarantee the thermal stability of the electrostrain in (NN-xBCZT ferroelectrics ceramics. This study not only clarifies the origin of thermally stable electrostrain in NN-xBCZT ferroelectric perovskite in terms of electrostrictive effect, but also provides ideas for developing applicable ferroelectric ceramic materials used in actuator devices with excellent thermal stability.

Large electrostrain and high energy-storage properties of (Sr1/3Nb2/3)4+-substituted (Bi0.51Na0.5)TiO3-0.07BaTiO3 lead-free ceramics

In this study, we developed a novel (Sr1/3Nb2/3)4+ complex ion dopant to tailor the electrostrain and energy-storage properties of (Bi0.5Na0.5)TiO3 (BNT)-based ferroelectric ceramics. The chemical formula of the investigated system is [0.93(Bi0.51Na0.5)0.07Ba)]Ti1-x(Sr1/3Nb2/3)xO3, where x = 0.0025, 0.005, 0.0075, and 0.01. The crystal structures, microstructures, and dielectric/ferroelectric/electrostrictive/energy-storage properties of the ceramics synthesized by a solid-state reaction method were thoroughly investigated. For the x = 0.01 composition, an ultrahigh electrostrain of 0.59 % was achieved under an electric field of 130 kV/cm. The strain response of this composition increased progressively with increasing temperature from 30 to 150 °C while maintaining good symmetry. Interestingly, the electrostrictive coefficient Q33 was shown to be strongly temperature-sensitive. The Q33 value was 0.018 m4/C2 at 30 °C and increased dramatically as the temperature increased, reaching a maximum value of 0.0378 m4/C2 at 150 °C. Furthermore, under a relatively modest electric field of 100 kV/cm, a high recoverable energy-storage density of 1.36 J/cm3 was obtained for the x = 0.0075 composition. These findings demonstrate that the addition of (Sr1/3Nb2/3)4+ complex ions can effectively tailor the electrostrain and energy storage properties of BNT-based ceramics. Moreover, the doping ion design principle can be applied to other BNT-based ferroelectrics, with potential for dramatic improvements in electrostrain and energy storage properties.

Large linear electrostrain of acceptor-donor Co-doped ZnO films

• Piezoelectric coefficient of Fe 3+ -Li + co-doped ZnO thin film is significantly enhanced by constructing acceptor-donor Fe 3+ -Li + ionic pairs in ZnO structure. • The Fe 3+ -Li + co-doped ZnO film has a large linear electrostrain. • The high permittivity has been obtained which is about one order of magnitude larger than that of pure ZnO film. • The piezoelectric performance of the films can be further improved by thermo-electrically treatment. In this paper we present the effective strategy of Fe 3+ and Li + co-doping to enhance the electrostrain of ZnO thin films. Zn 0.88 (Fe 0.06 Li 0.06 )O thin film exhibits an excellent d 33 * value of 415 pm/V and large linear electrostrain of 0.68% after thermal-electric treatment. Both the X-ray diffraction and first principle calculation results have indicated that the Fe 3+ and Li + ions are inclined to adopt a preferential alignment along the edges approximately parallel to [001] direction in the zinc-oxygen tetrahedron and constitute a defect dipole (ionic pairs). It is considered that the local lattice distortion and the electric field-triggered polarization extension and rotation generated by preferential distributed Fe 3+ -Li + ionic pairs are responsible for the outstanding piezoelectric properties and large linear electrostrain.

Constructing Relaxor/Ferroelectric Pseudocomposite To Reveal the Domain Role in Electrostrain of Bismuth Ferrite-Barium Titanate Based Ceramics.

Bismuth ferrite-barium titanate (BF-BT) based ceramics have attracted extensive attention due to its excellent energy conversion. Recently it has been found that BF-BT based ceramics with large electrostrain are usually accompanied by a special domain configuration in which weak and strong piezoresponse domain grains coexist. In this work, we purposefully constructed the special domain configuration in the pseudocomposite ceramics of (1 - x)0.55BF-0.4BT-0.05BZN/x(0.7BF-0.3BT) (relaxor-like phase/ferroelectric phase, RE/FE) by a "two-step" method. Macroproperty characterization suggests that the critical component pseudocomposite ceramic (x = 50%) with the special domain structure can exhibit a maximum electrostrain value (S ∼ 0.28%) at 6 kV/mm, almost 3-fold to that (S ∼ 0.1%) of the two end members and 63% higher than that (S ∼ 0.17%) of the same component ceramic prepared by the "one-step" method. Further mesoscopic structure results show that the "two-phase" composite can induce the formation of grain dependent domain at nanoscale, and just this special domain conformation is conducive to a significant improvement in electrostrain. Therefore, the large strain in BF-BT-based ceramics is mainly caused by the special microstructure rather than component.

Morphotropic Relaxor Boundary Construction Highly Boosts the Piezoelectric Properties of Bi-Based Lead-Free Thin Films.

To achieve large electrostrain and low hysteresis, we further optimized a morphotropic phase boundary (MPB) by modulating its local polar symmetries. The construction of a morphotropic relaxor boundary (MRB) in thin films can be achieved by suitable introduction of Bi(Fe0.95Mn0.03Ti0.02)O3 into (Bi0.5Na0.5)TiO3-SrTiO3 to form a solid solution. The designed thin film achieves surprising piezoelectric properties with an inverse piezoelectric coefficient of 179.7 pm V-1 and negligible hysteresis. The composition of two relaxors with different local polar symmetries (tetragonal nanoregions and rhombohedral nanoregions), namely, an MRB, and the coexistence of multiscale domain structures can greatly weaken the anisotropy of polarization, degrade the energy barrier, attenuate the discontinuity of polarization, and achieve a large electrostrain and low hysteresis. The domain dynamics of the PNRs under the action of an external excitation field are analyzed to clarify the enhancement mechanism. This construction of MRBs is feasible for producing lead-free piezoelectric films with high-voltage electrical properties and low hysteresis, and various experimental design and theoretical references are provided.

Large Electrostrain Induced by Co-Doping of Sr2+ and Ta5+ in a and B Sites for Bnt-Based Piezoelectric Ceramics

Large Electrostrain Induced by Co-Doping of Sr2+ and Ta5+ in a and B Sites for Bnt-Based Piezoelectric Ceramics

The effect of B site doping of Nb5+ and aging process on the properties of BNKT-BT lead-free piezoelectric ceramics

This research explored the influence of Nb 5+ doping on the electrical properties and microstructure of [0.852(Bi 0.5 Na 0.5 )-0.11(Bi 0.5 K 0.5 )-0.038Ba]Ti (1- x ) Nb x O 3 (designated as BNKT-BT). The BNKT-BT samples were fabricated and the XRD results showed that the doping of Nb 5+ ions induced a transformation from the coexistence of both rhombohedral and tetragonal phase to a single pseudo cubic phase. Also, the doping of Nb 5+ ions caused the temperature of ferroelectric state-ergodic relaxor state transition to decrease below the room temperature (RT). The SEM observations showed that the Nb 5+ doping had a minor effect on the grain size of BNKT-BT samples. In addition, the samples achieved a large electrostrain of 0.43% ( d * 33 = S max / E max = 614 pm/V) under 7 kV/mm at RT. Moreover, the aging process employed at 80 °C for two weeks in air could effectively increase the electrostrain from 0.38% to 0.41% under 6 kV/mm ( d * 33 = 683 pm/V) and reduce the strain hysteresis from 57% to 34%. These results indicated that the B site doping, combined with the aging process, could provide an effective way to enhance the electrostrain performance of lead-free piezoelectric ceramics. • Niobium ions as dopants can effectively destroy the long-range ferroelectric order of the BNKT-BT-based ceramics. • At room temperature, with the addition of niobium ions, the samples change from ferroelectric state to ergodic relaxed state. • Niobium ions doping and the aging process provide an effective means for the development of practical BNT-based ceramics.

Large electrostrain with nearly-vanished hysteresis in eco-friendly perovskites by building coexistent glasses near quadruple point

One of the key questions in the development of eco-friendly piezoelectrics lies in how to achieve large hysteresis-free electrostrain responses in a facile and effective manner, to meet the requirements of high-precision electromechanical devices. Here, through integrating phase-field modeling and experimental approach, a highly effective strategy is proposed for large electrostrain outputs with negligible hysteresis in lead-free perovskite oxide ferroelectrics, by building coexistent glasses with diverse local symmetries near a quadruple point rendering low energy barriers between different polar states. Guided by phase-field simulations, a superior electrostrain of ~ 0.21% with nearly-zero hysteresis is obtained at the constructed glasses region near the quadruple point of Bi-doped Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 ceramics, outperforming almost state-of-the-art lead-free piezoelectric substitutions when taking both electrostrain and hysteresis into account. The strategy of building coexistent glasses near the quadruple point provides a novel design paradigm for high-performance piezoelectric materials in the application of high-precision actuators.

Large nonlinear electrostrain and piezoelectric response in nonergodic(Na,K)0.5Bi0.5TiO3: Synergy of structural disorder and tetragonal phase in proximity to a morphotropic phase boundary

Among the different piezoceramics, ${\mathrm{Na}}_{0.5}{\mathrm{Bi}}_{0.5}\mathrm{Ti}{\mathrm{O}}_{3}$ (NBT)-based systems have the unique distinction of exhibiting very large electrostrain $(&gt;0.5%)$ when pushed at the threshold of ergodic--nonergodic relaxor transition. However, this strategy severely compromises the system's weak-signal piezoelectric response (${d}_{33}$). Here, we show that a similar level of electrostrain is feasible together with high ${d}_{33}$ by a different approach. In our approach, the system is kept well within the nonergodic relaxor regime close to an interferroelectric instability, and the inherent structural (tilt) disorder is exploited for large reverse switching of the ferroelastic domains in the field-stabilized ferroelectric phase. A synergy of this combination is demonstrated in $(1\ensuremath{-}x){\mathrm{Na}}_{0.5}{\mathrm{Bi}}_{0.5}\mathrm{Ti}{\mathrm{O}}_{3\ensuremath{-}}(x){\mathrm{K}}_{0.5}{\mathrm{Bi}}_{0.5}\mathrm{Ti}{\mathrm{O}}_{3}$; $x=0.25$ which exhibit electrostrain of \ensuremath{\sim}0.6% and ${d}_{33}$ (\ensuremath{\sim}210 pC/N). With the added advantage of high depolarization temperature $({T}_{d}\ensuremath{\sim}185{\phantom{\rule{4pt}{0ex}}}^{\ensuremath{\circ}}\mathrm{C})$ this piezoceramic stands unique for showing the best combination of the three most sought after properties.

Low hysteresis and temperature stable electrostrain in 0.97(0.94Na0.5Bi0.5TiO3-0.06BaTiO3)-0.03AgNbO3/xZnO composite ceramics

Na0.5Bi0.5TiO3-based solid solutions are one of the most promising lead-free piezoelectric candidates since they can be easily tailored to exhibit large electrostrain. However, the large hysteresis and temperature-dependence of the electrostrain response are longstanding obstacles for their practical applications. In the present study, 0–3 type composites were developed with 0.97(0.94Na0.5Bi0.5TiO3-0.06BaTiO3)-0.03AgNbO3 (NBT-6BT-3AN) matrix phase and ZnO inclusions. The optimum addition of 5 wt.% ZnO in the composites leads to reduction in hysteresis of electrostrain by 35% in comparison with pure NBT-6BT-3AN at room temperature. Meanwhile, electrostrain of the composites maintains superior temperature stability, with a variance of less than ±10% in the temperature range between 25 and 125 °C. The reason for the improvement of electrostrain is proposed to be attributed to the ergodic/nonergodic mixture phases induced by residual stress between the inclusion and matrix, as well as the phase evolution caused by the incorporation of Zn2+ into the matrix. Therefore, this work provides a new strategy to improve the electromechanical properties of Na0.5Bi0.5TiO3-based ceramics.

In situ poling X-ray diffraction studies of lead-free BiFeO3–SrTiO3 ceramics

The origin of the large electrostrain in BiFeO3-BaTiO3 (BF-BT) ceramics is controversial and has been attributed to either a field-induced transition to a long-range ferroelectric (FE) state or to multi-symmetry, polar nanoregions within a pseudocubic matrix whose vectors approximately align with the direction of the applied field. The (1-x)BiFeO3-xSrTiO3 (BF-xST) solid solution is structurally and microstructurally similar to BF-BT and provides a further case study to assess the origin of electrostrain. In BF-xST, electrostrain is optimized at x = 0.4 (0.15%) which zero field, room temperature full-pattern X-ray diffraction (XRD) Rietveld refinement and scanning/transmission electron microscopy suggest is composed of 15% rhombohedral (R) cores, surrounded by 85% pseudocubic (PC) shells. In-situ poling synchrotron XRD reveals that all peaks remain singlet and exhibit no change in full width half maximum up to 100 kV cm−1, confirming the absence of long-range FE order and the retention of short-range polar order, despite the large applied field. Strain anisotropy (calculated from individual peaks) of ε220 > ε111 > ε200 and the associated strain orientation distribution however, indicate the existence of local orthorhombic (O), R and tetragonal (T) symmetries. The data therefore imply the existence under poling of multi-symmetry polar nanoregions in BF-0.4ST rather than a long FE phase, supporting the model described by Wang and co-workers (2019) for BF-BT compositions.

Large electrostrain and high energy-storage of (1-x)[0.94(Bi0.5Na0.5) TiO3-0.06BaTiO3]-xBa(Sn0.70Nb0.24)O3 lead-free ceramics

(1-x)[0.94(Bi0.5Na0.5)TiO3-0.06BaTiO3]-xBa(Sn0.70Nb0.24)O3 (abbreviated as BNTBT-100xBSN) lead-free ceramics were fabricated with a relative density greater than 96 %, and the structure as well as performance were tested. BNTBT-100xBSN ceramics are pseudo-cubic perovskite structure, with dense surface morphology. Doping BSN can effectively reduce the dielectric loss of ceramics and increase the relaxation properties to a certain extent. The randomly distributed ferroelectric phase was replaced by polar nano regions, thereby improving the electro-strain and energy storage performance of the system. The largest electro-strain and the corresponding normalized strain (d33*) reach ~ 0.43 % and 633 pm/V respectively in the BNTBT-1BSN ceramic. The largest effective energy storage density reaching ~ 1.28 J/cm3 was tested in BNTBT-2BSN. BNTBT-100xBSN ceramics provide a feasible idea for the systematic research of lead-free ferroelectrics and improvements in electro-strain and energy storage applications.

Large electro-strain with excellent fatigue resistance of lead-free (Bi0.5Na0.5)0.94Ba0.06Ti1-x(Y0.5Nb0.5)xO3 perovskite ceramics

A series of lead-free (Bi0.5Na0.5)0.94Ba0.06Ti1-x(Y0.5Nb0.5)xO3 (for 0 ≤ x ≤ 0.03) perovskite ceramics were fabricated using a solid-state reaction technique. The effects of (Y0.5Nb0.5)4+ ions doping on phase structure, piezoelectric properties, AC impedance, and fatigue resistance were systematically studied. Crystal structure as a function of the composition revealed a single perovskite lattice structure with dense micromorphology. The transition temperature of the non-ergodic and ergodic relaxor ferroelectric phase shifted to near ambient temperature with increasing composition, which was related to the destruction of the long-range ordered ferroelectric domains. Hence, the transformation of ferroelectric-to-relaxor phase was easier under applied electric field at room temperature. The ceramic for x = 0.01 composition attained a large unipolar strain of ~ 0.452% with a corresponding normalized strain (d33*) of ~ 603 pm/V under applied 75 kV/cm field. Besides, the excellent fatigue resistance of the sample was obtained after 105 switching cycles under 70 kV/cm. These phenomena demonstrated that (Bi0.5Na0.5)0.94Ba0.06Ti1-x(Y0.5Nb0.5)xO3 ceramics might be suitable for a wide range of electronic equipment applications such as actuators and sensors.

Fine-grained relaxor ferroelectric PMN-PT ceramics prepared using hot-press sintering method

Relaxor ferroelectric PbMg1/3Nb2/3O3-PbTiO3 (PMN-PT) ceramics are high-performance piezoelectric materials that are widely used in many electronic devices. However, it is extremely difficult to manufacture thin piezoelectric components dozens of micrometers in size using commercial coarse-grained PMN-PT ceramics. This limits the application of PMN-PT ceramics to high-frequency ultrasonic devices. In this work, we prepared a dense, fine-grained PMN-PT ceramic at low temperature using a hot-press sintering (HPS) method. The HPS ceramic had small grains with an average size of 1 μm and maintained high performance with a large permittivity (εr = 4500), piezoelectricity (d33 = 650 pC/N), and electrostrain (SE = 0.14% at 20 kV/cm). The large volume fraction of grain boundaries led to stronger relaxor behavior of the fine-grained PMN-PT ceramic than of the normal coarse-grained one. Owing to its small grains and high piezoelectric performance, this fine-grained PMN-PT ceramic meets the strict requirements of manufacturing thin piezoelectric components. Our results demonstrate that PMN-PT ceramics have great potential for developing low-cost, high-frequency ultrasonic devices by replacing expensive piezoelectric single crystals.

Designed morphotropic relaxor boundary ceramic exhibiting large electrostrain and negligible hysteresis

Electromechanical materials with large electrostrain and low hysteresis are strongly desired for high-precision actuator applications. Despite extensive studies for more than half a century, it is still a challenge to obtain large electrostrain and low hysteresis simultaneously due to the so-called strain-hysteresis trade-off. Here, we report a mechanism to overcome this trade-off: a ceramic composition locating at a morphotropic relaxor boundary (MRB), exhibits enhanced electrostrain and reduced hysteresis as compared with off-MRB compositions. The MRB, a composition-induced boundary separating two relaxors with different local polar symmetries, is attained by transforming an morphotropic phase boundary (MPB) in Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) through doping lanthanum. The performances of large electrostrain of 0.227% and negligible hysteresis of 3% of MRB composition are the best, as evidenced by occupying a virgin region in the strain-hysteresis chart of relaxor electromechanical ceramics. Moreover, this MRB ceramic maintains the large electrostrain and low hysteresis over a temperature range from 35 to -35 °C. The understanding of abnormal effects of MRB is established through combining microstructure observations and Landau theory analysis: the MRB composition with morphotropic nanodomain structure and higher degree of local structural heterogeneity shows a flatter energy profile with much lower energy barrier, thereby leading to a large electrostrain and negligible hysteresis. Our work demonstrates that the MRB is an effective mechanism to design relaxor materials with large electrostrain and low hysteresis simultaneously. We predict that more high-performance MRB electromechanical materials will be found in properly doped MPB systems.

Critical state to achieve a giant electric field-induced strain with a low hysteresis in relaxor piezoelectric ceramics

Due to the extrinsic contribution of domain wall motions to electro-strains, the incompatibility of the large electro-strain with a low hysteresis in piezoelectric ceramics is a stumbling block for designing high-performance piezoelectrical actuators. Herein, we report a critical state in relaxor ferroelectric systems enables to enhance the electro-strain and to reduce the hysteresis simultaneously. A room temperature ergodic relaxor state dominated by nanodomains with different local symmetries can be obtained by introducing Bi(Zn1/2Ti1/2)TiO3 into 0.73 Pb(Mg1/3Nb2/3)O3-0.27PbTiO3 matrix. Like the morphotropic phase boundary (MPB) in ferroelectrics, the coexistence of different local symmetries is capable of facilitating the transition from the ergodic relaxor state to the ferroelectric under the applied field due to the ease of polarization rotation, thereby leading to a giant electro-stain (0.24%) under an electric field of 50 kV/cm. Furthermore, the field-induced ferroelectric state with the long-range ferroelectric order can spontaneously reverse back to the initial ergodic relaxor state during unloading the electric field, which contributes to a low hysteresis (15.4%). The present work not only introduces a solid solution system with excellent electro-strain properties but also affords a guidance for manipulating the electro-strain behavior by modulating phase structures and domain configurations of piezoelectric ceramics.