Large Electrostrictive Effect Research Articles

Enhanced energy storage properties and large electrostrictive effect of Bi0.35Na0.35Ba0.09Sr0.21Ti(1-x)(Al0.5Nb0.5)xO3 relaxor ceramics

Ferroelectric ceramics have good piezoelectric and ferroelectric properties and can be used for energy storage equipment and actuators. Nevertheless, current research on dielectric capacitors has only focused on the energy storage density, but ignored efficiency. Moreover, conventional piezoelectric materials have a large strain hysteresis. In this work, (Al0.5Nb0.5)4+ (AN) complex ions doped 0.7Bi0.5Na0.5TiO3-0.3Ba0.3Sr0.7TiO3 (BNBST) ceramics were prepared. Doping AN destroyed the long-range ordered ferroelectric domains and generated polar nano regions, resulting in a gradual thinning and inclination of polarization hysteresis loops and an increase in relaxor degree. For BNBST-3AN ceramics, a Wrec of 1.52 J/cm3 and a η of 92.1% were achieved at 150 kV/cm. Meanwhile, BNBST-3AN ceramics had good energy storage temperature stability and cycling performance. The AN doping reduced the strain hysteresis in BNBST ceramics. BNBST-2AN ceramics exhibited a longitudinal electrostrictive coefficient Q33 ∼ 0.0292 m4/C2 and a field-induced strain of 0.25% with low strain hysteresis (6.67%). Furthermore, BNBST-4AN ceramics had superior dielectric temperature stability from 24 to 270 °C. All results show that BNBST-100xAN ceramics have great promise for energy storage devices and actuators.

Large electrostrictive effect and dielectric properties of (K0.5Na0.5)NbO3-BaZrO3 ceramics

Electrostrictive materials are sought after in high-precision displacement actuators due to their ultra-low hysteresis electrostrain. Here we report a very promising electrostrictive material by doping barium zirconate into a sodium potassium niobate matrix. Also, the dielectric behaviors and electrostrictive properties of (1-x)K0.5Na0.5NbO3-xBaZrO3 (x = 0.10, 0.12, 0.14 and 0.16) ceramics are investigated in details. The doping of barium zirconate allows the diffuse phase transition to occur near room temperature. Diffuse dielectric anomalies at high temperatures are observed in poled ceramics, which are closely related to the activation of defects. High electrostrain (∼0.1 %) with ultra-low strain hysteresis (< 12 %) are obtained at x = 0.14. Moreover, electrostrain exhibits excellent stability over a wide temperature range from 30 ℃ to 120 ℃.Further, the electrostrictive coefficient of ∼0.066 m4/C2 for the component was determined at high temperatures and high electric fields, demonstrating the excellent potential of the K0.5Na0.5NbO3-BaZrO3 solid solutions as electrostrictive materials.

Large electrostrictive effect and strong photoluminescence properties in Sm2O3-modified lead-free potassium sodium niobate-based piezoelectric ceramics

In this work, the phase transition behavior and electrostrictive and photoluminescence properties of Sm2O3-modified 0.965(K0.48Na0.52)(Nb0.95Sb0.05)–0.035Bi0.5(Na0.82K0.18)0.5HfO3 (KNNS–0.035BNKH) ceramics were investigated. Results showed that the phase structure of the Sm2O3-modified ceramics evolved from coexisting orthogonal and tetragonal ferroelectric phases to a relaxor pseudocubic phase along with the strong destruction of the long-range ferroelectric order. Domain switching in Sm-modified ceramics with a relaxor pseudocubic phase became difficult, evident from the PFM images. Consequently, large electrostrictive effect with an electrostrictive coefficient of 0.022 m4/C2 was obtained in 1.0 mol% Sm-modified samples. With regard to long-term stability, the materials exhibited temperature-independent (20–100 °C) and fatigue−free (up to 105 cycles) behavior, which guarantees their application in various devices. The KNNS–0.035BNKH–xSm ceramics have the advantages of photoluminescence performance with bright orange emission under 407 nm visible light excitation. Overall, KNNS−0.035BNKH−xSm ceramics have broad application prospects in multifunction devices due to their large electrostrictive effect, excellent photoluminescence performance, and long-term stability.

Large electrostrictive effect in Sn-doped NBT–BT lead-free relaxor ceramics

In this work, we design and adjust the composition in [Formula: see text]–[Formula: see text] lead-free relaxor ferroelectrics by doping SnO2 to introduce a relaxor phase and accordingly obtain prominent lead-free electrostrictors. It was found that all the samples exhibited ideal features of relaxor ferroelectrics and the ferroelectric-relaxor phase transition temperature of the ceramics was adjusted to near or below room temperature after doping with a handful of [Formula: see text]. A relatively high electrostrictive coefficient [Formula: see text] of 0.0293 m4/C2 was achieved for the composition with [Formula: see text], which was attributed to the formation of relaxor pseudocubic phase developed by the [Formula: see text] substitution. These results provide some instructive thoughts for the further development of [Formula: see text]-based electrostrictive materials by B-site doping.

A 30-nm thick integrated hafnium zirconium oxide nano-electro-mechanical membrane resonator

This paper reports a 30 nm-thick integrated nano-electro-mechanical resonator based on atomically engineered ferroelectric hafnium zirconium oxide (Hf0.5Zr0.5O2) film. A 10 nm-thick Hf0.5Zr0.5O2 layer is atomically engineered through capping with 10 nm-thick titanium nitride (TiN) layer and rapid thermal annealing to promote the orthorhombic crystal phase with strong ferroelectric properties. The resulting metal-ferroelectric-metal (MFM) membrane is then patterned to create an integrated nano-electro-mechanical resonator with an overall thickness of 30 nm and a planar-to-vertical aspect ratio exceeding 104:1. Benefiting from large electrostrictive effects in ferroelectric Hf0.5Zr0.5O2, the 30 nm-thick nanomechanical resonator is excited into flexural resonance at 195 kHz with a very large vibration amplitude of ∼100 nm. The transmission response of the nano-electro-mechanical resonator is extracted, using a two-port apodization of the TiN electrodes, showing quality factors (Q) of 15 and 3300 at atmospheric and 10−7 Torr ambient pressures, respectively. Finally, the structural robustness of the MFM nano-membrane is explored through the application of a ∼24 μm deflection, using a point-force by a micro-probe, highlighting the extended elasticity despite the small thickness and ultra-high aspect ratio. The atomic-level thickness, fully integrated operation, high Q, and structural robustness of the Hf0.5Zr0.5O2-based nano-membrane resonator promise its potential for the realization of highly integrated transducers for chip-scale classical and quantum information processing and sensing applications.

Enhanced Electrostrictive Properties and Thermal Stability in Zn-Modified 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 Ceramics

A 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 (PMNT) relaxor ferroelectric ceramic is a good dielectric and electrostrictive actuator material. Nevertheless, important engineering problems of further enhancing its electrostrictive effect and increasing its thermal stability must be solved to promote its applications. In this work, the Zn-doped PMNT (PMNT/xZn2+) ceramics were prepared by the niobite precursor synthesis method. The transition of the PMNT/xZn2+ ceramics from relaxor ferroelectric to normal ferroelectric was realized, increasing the residual polarization (Pr), saturation polarization (Pm), the ferroelectric-paraelectric transition temperature at emax (Tm) and electric field induced strain (S) from x = 0.0 (Pr = 5.3294 μC/cm2, Pm = 26.6690 μC/cm2, Tm = 45°C, S = 1.08‰) to x = 8.0 (Pr = 19.9005 μC/cm2, Pm = 30.3718 μC/cm2, Tm = 70°C, S = 1.42‰). In addition, the upper temperature limit of the materials with a large electrostrictive effect (greater than 1‰) was extended from 40°C to 80°C. The main reason for these improved properties is that the magnesium ions were replaced by the highly reactive zinc ions at the B-site of the ferroelectric perovskite structure during the sintering and formed a certain amount of component segregation that increased the size of the polar nanoregions/domains and improved the polarizability of the materials.

Large electrostrictive effect and energy storage density in MnCO3 modified Na0.325Bi0.395Sr0.245□0.035TiO3 lead-free ceramics

The Na0.325Bi0.395Sr0.245□0.035TiO3 + x % MnCO3 (NBST-100xMn) lead-free ceramic samples had been fabricated by solid-state reaction method. Microstructure and electrical properties with the addition of MnCO3 had been studied in detail. The NBST-4Mn showed a low hysteresis behavior with the maximum electrostrictive coefficient (Q) of 0.0294 m4/C2 and the recoverable energy storage density (Wrec) of 1.3 J/cm3 at 95 kV/cm. In addition, the electrostrictive effect and energy storage ability presented outstanding temperature stability and fatigue resistance, which indicated a promising lead-free ceramic for high precise actuator.

Large electrostrictive effect in Mn-doped BCZT ferroelectric ceramics

The electric field in ferroelectric ceramics can induce notable deformations or strains based mainly on the electrostrictive effect if the driving field is sufficiently large (normally larger than the coercive field). Therefore, a large electrostrictive effect is highly desired to achieve a high strain output. In the present work, 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BCZT50) ferroelectric ceramics doped with different numbers of Mn ions were synthesized and their dielectric and ferroelectric properties were studied to comprehensively evaluate the electrostrictive effect in this system. The doping levels were set as 0.0025, 0.005, 0.01, and 0.02. It was found that Mn ions could lower the temperature corresponding to the maximum permittivity, Tm, drastically and induce diffuse phase-transition behaviors simultaneously. Most importantly, a purely electrostrictive effect with a longitudinal electrostrictive coefficient, Q33, as large as 0.0466 m4/C2 was observed between 22 and 80 °C. The Q33 of Mn-doped BCZT50 ceramics is much higher than some representative lead-based and lead-free ferroelectric ceramics. In this paper, a potential lead-free ferroelectric system with a large electrostrictive effect, which has potential applications in electrostrictive actuators, is reported.

Large electrostrictive effect and high energy storage performance of Pr3+-doped PIN-PMN-PT multifunctional ceramics in the ergodic relaxor phase

The photoluminescence, dielectric relaxation, ferroelectric hysteresis, and field-induced strain properties of Pr3+-doped 0.24Pb(In1/2Nb1/2)O3-0.42Pb(Mg1/3Nb2/3)O3-0.34PbTiO3 (PIN-PMN-PT:Pr3+) multifunctional ceramics have been investigated. It was found that Pr3+ doping enhanced the dielectric diffuseness and relaxation behavior of PIN-PMN-PT ceramics. Slim P-E loops and S-E curves appear in PIN-PMN-PT:Pr3+ ceramics when the Pr3+ doping concentration reaches 1.4 mol%. Local domain configurations associated with phase transitions were investigated by piezoresponse force microscopy (PFM). Large electrostrictive coefficient Q33 (˜0.03 m4/C2) and high energy-storage efficiency η (92%) were obtained in 2 mol% Pr3+-doped PIN-PMN-PT ceramic in the ergodic relaxor (ER) phase at room temperature. The giant electrostrictive effect and excellent energy-storage performance are related to the field-induced dynamic behavior of polar nanoregions (PNRs). The results show that the PIN-PMN-PT:Pr3+ system is an excellent multifunctional material for making electromechanical and energy storage devices.

Large electromechanical strain and electrostrictive effect in (1 − x)(Bi0.5Na0.5TiO3–SrTiO3)–xLiNbO3 ternary lead-free piezoelectric ceramics

Lead-free (1 − x)(0.8Bi0.5Na0.5TiO3–0.2SrTiO3)–xLiNbO3 (BNST–xLN, x = 0–0.08) piezoelectric ceramics were fabricated by a solid-state sintered technology. The effects of LN-doping on the structural and electrical properties of the BNST–xLN system were systematically investigated. The results of Raman spectroscopy revealed that the substitution of LN softens the phonon vibrations in the BNST–xLN system, in accordance with the remarkable reduction in the phase transition temperature (TF−R), remnant polarization (Pr), negative strain (Sneg) and piezoelectric coefficient (d33). However, the degradation of the long-range ferroelectric orders was accompanied by a significant increase in the electric field–induced strain response. At x = 0.04, a maximum unipolar strain of ~ 0.36% with a corresponding normalized strain (Smax/Emax) of ~ 600 pm/V was obtained at room temperature, which should be mainly ascribed to the reversibly electric field-induced phase transition between the ergodic relaxor and ferroelectric phases due to their comparable free energies in the two-phase coexistence region. Moreover, it was also found that the BNST–xLN system processes predominant electrostrictive behaviors with relatively high electrostrictive coefficient (Q33) and excellent temperature stability when the field-induced phase transition cannot be trigged by the applied electric field, as evidenced by a fact that the Q33 value of BNST–0.08LN ceramic keeps almost constant as high as ~ 0.028 m4/C2 in the temperature range from room temperature to 120 °C.

Temperature-insensitive strain and bright upconversion luminescence in Er-modified 0.88(Bi0.5Na0.5)TiO3-0.22(Bi0.5K0.5)TiO3 ceramics

In this work, 0.88(Bi0.5Na0.5)TiO3-0.22(Bi0.5K0.5)TiO3-xmol%Er (x = 0.00–0.80, 0.88BNT-0.22BKT-xmol%Er) lead-free piezoelectric ceramics were prepared by the solid state reaction method and the effects of Er addition on structure and electrical properties of 0.88BNT-0.22BKT ceramics were investigated. Results showed that Er additive within the content of 0.80mol% diffuse into the 0.88BNT-0.22BKT lattice to form a pure perovskite phase structure. Pure 0.88BNT-0.22BKT ceramic shows a large field strain of 0.21% at room temperature, but it is depended greatly on the temperature. As 0.4–0.8mol%Er doped into the 0.88BNT-0.22BKT host, they show a temperature-insensitive strain characteristic in the temperature range from room temperature to 120 °C. Furthermore, a large electrostrictive effect with high electrostrictive coefficient Q33 of 0.016–0.019m4/C2 comparable with that of traditional lead-based electrostrictors is obtained in these Er-modified materials. Moreover, Er-modified 0.88BNT-0.22BKT samples exhibit a strong green upconversion emission under a 980 nm LD excitation. These results suggest that this kind of material is promising candidate used as multifunctional devices by integrating its electrostrictive and upconversion luminescence properties.

Electric-field-induced local distortion and large electrostrictive effects in lead-free NBT-based relaxor ferroelectrics

In this work, the (0.94-x)(Na0.5Bi0.5)TiO3-0.06Ba(Zr0.05Ti0.95)O3-x(Sr0.8Bi0.1□0.1)TiO2.95 (NBT-BZT-xSBT) ternary relaxor ferroelectrics were chosen as the studied compositions, and the in-situ electric-field-dependent Raman spectra and PFM measurements were performed to systematically investigate the structural distortion and local polarization switching. Results showed that the SBT enhances the relaxor degree and depresses the field-induced local distortion. The higher field required initially for obtaining polarization saturation with increasing SBT concentration is related to overcoming the hindrance posed by the local structural heterogeneity. Most intriguingly, a giant and temperature-insensitive electrostrictive effect (Q33 = 0.035 m4/C2, RT∼120 °C: variation less than 2%) was achieved in SBT5 composition. Such performance is one of the best values ever reported on lead-free and lead-based electrostrictive materials. A modified Landau model was proposed to phenomenologically elaborate the underlying mechanisms. Our findings illustrate that understanding structural changes at multiple length scale will be helpful for designing novel lead-free piezoceramics with high performance.

Large electrostrictive effect in lead-free (Bi.5Na.5)TiO3-based composite piezoceramics

The quadratic electrostrictive effect possesses several unique advantages over the piezoelectric effect, including a fast response speed, temperature stability, hysteresis-free characteristic. In this regards, we report a 0–3 type 0.92(Bi.5Na.5)TiO3−0.06BaTiO3−0.02(K.5Na.5)NbO3:6 wt% Bi4Ti3O12 (BNT-BT-KNN: BiT) composite ceramics to achieve the competent electrostrictive effect at room temperature. The electrostrictive behavior of composite ceramics was systematacially explored with respect to driving field, temperature, frequency and cycles. The manufactured composite ceramic is featured by not only large room-temperature electrostrictive coefficient Q33 of 0.0327 m4 C−2 but also superior thermal stability in the temperature range from 25 °C to 120 °C. Simultaneously, the gained electrostrictive response exhibited relatively good frequency-dependent and fatigue character. It is demonstrated that construct of a 0–3 type connectivity composite provides a highly effective path to tailor electrostrictive characteristic of BNT-based ceramics. The current study shows a significant advancement in the area of lead-free electrostrictive materials and can inspire potential interest in search for novel BNT-based ceramics with promising electrostrictive effect.

Large electrostrictive effect and high optical temperature sensing in Bi0.5Na0.5TiO3-BaTiO3-(Sr0.7Bi0.18Er0.02)TiO3 luminescent ferroelectrics

(0.94-x)Bi0.5Na0.5TiO3-0.06BaTiO3-x(Sr0.7Bi0.18Er0.02)TiO3 (BNT-BT-xSBET) luminescent ferroelectric ceramics were designed. Dielectric measurements revealed that two dielectric anomalies were suppressed and shifted to a lower temperature with increasing the SBET concentration. As a result, a nearly hysteresis-free strain of ~ 0.11% with an electrostrictive coefficient Q33 of 0.029m4/C2 was obtained for the composition with x = 0.30, which exhibited a thermal stability and fatigue-resistance. Meanwhile, two thermally coupled green up-conversion luminescence were observed, in which the maximum sensitivity was found to be 0.0032K−1 at 434K. This indicates that the system is very promising for multifunctional applications in electromechanical and temperature sensing device.

Thermally stable electrostrains of morphotropic 0.875NaNbO3-0.1BaTiO3-0.025CaZrO3 lead-free piezoelectric ceramics

The 0.875NaNbO3-0.1BaTiO3-0.025CaZrO3 relaxor ferroelectric ceramics were reported to exhibit thermally stable electrostrains (∼0.15% @ 6 kV/mm) from room temperature (RT) to ∼175 °C and comparable strain hysteresis (&amp;lt;13%) to that of typical lead-based piezoelectric ceramics. Dominant strain contribution mechanisms with increasing temperature were analyzed by means of temperature-dependent permittivity, polarization, and strain measurements and synchrotron x-ray diffraction. The rhombohedral (R) and tetragonal (T) morphotropic phase boundary provided a solid structural base for temperature-stable piezoelectric strains from RT to ∼140 °C. The growth of polar nanoregions (pseudocubic) into microdomains (R) and subsequent field-induced R-T phase transition, as well as large electrostrictive effects, sequentially contributed to high electrostrain levels in the proximity of the Curie temperature (from 140 to 175 °C). In addition, the observed low strain hysteresis was attributed to the small strain fraction from domain switching. These experimental results demonstrated that NaNbO3-based relaxor ferroelectrics might be potential lead-free materials for actuator applications.

Large electrostrictive effect in (Ba1-xGd2x/3)Zr0.3Ti0.7O3 relaxor towards moderate field actuator and energy storage applications

The need of lead-free high performance ceramics with large electrostrictive effect, minimum hysteresis loss and energy storage ability at room temperature has become indispensable. At room temperature one of the key challenges in ceramic materials is to enhance the electrostrictive and energy storage properties simultaneously. In this regards, lead-free gadolinium modified barium zirconate titanate (Ba1-xGd2x/3)(Zr0.3Ti0.7)O3 (x = 0.02, 0.04, 0.06, 0.08, 0.10) ceramic was experimentally investigated to gain the competent electromechanical parameters near room temperature. Dielectric measurements exhibit a diffuse type of phase transition of relaxor phenomena and slim hysteresis loop with low remnant polarization and low hysteresis loss were observed. A moderate electric field of 30 kV/cm, recoverable energy and storage efficiency increases with Gd content. Strain-electric field hysteresis curves such as S-E, S-E2, and S-P2 profiles indicate improved electrostrictive characteristic of the ceramics. Results show that a maximum strain S ∼ 0.083% with large electrostrictive coefficient Q11 ∼ 0.054 m4/C2 and M11 ∼ 0.142 × 10−16 m2/V2 were obtained for x = 0.02 based BGdZT composition near relaxor-paraelectric phase boundary. The behavior of electrostrictive effect and energy storage efficiency suggested new possibilities of high precision lead-free ceramic actuator in a moderate field.

Large electrostrictive effect and strong photoluminescence in rare-earth modified lead-free (Bi0.5Na0.5)TiO3-based piezoelectric ceramics

In this study, new lead-free luminescent electrostrictive materials have been fabricated by introducing trivalent RE3+ (RE=Sm, Pr and Eu) as the activator into 0.93(Bi0·5Na0.5)TiO3–0.07BaTiO3 (BNBT7) ceramics. A high, purely electrostrictive effect with exceptionally good temperature-independent and fatigue-free behavior was obtained in RE-modified BNBT7 ceramics. These materials are also attractive for their strong photoluminescence with bright reddish-orange emission (RE=Sm) or red emission (RE=Pr, Eu) upon blue or green light excitation. These results suggest that this kind of materials has potential application as a multifunctional device by integrating its excellent luminescence and electrostrictive properties.

Large electrostrictive effect and bright upconversion luminescence in Er-modified 0.92(Bi0.5Na0.5)TiO3–0.08(Ba0.90Ca0.10)(Ti0.92Sn0.08)O3 lead-free ceramics

In this study, a new lead-free luminescent electrostrictive material has been obtained by introducing trivalent Er3+ as the activator into 0.92(Bi0.5Na0.5)TiO3–0.08(Ba0.90Ca0.10)(Ti0.92Sn0.08)O3 (BNT–0.08BCST). A high, purely electrostrictive effect (the electrostrictive coefficient Q33 reaches up to 0.028m4/C2) with exceptionally good fatigue resistance (up to 106 cycles) and thermostability (25–140°C) is obtained in 0.2mol%Er-modified BNT–0.08BCST ceramics. Besides the excellent electrostrictive properties, Er3+-modified BNT–0.08BCST samples exhibit a strong green-red upconversion emission, and the emission intensities are strongly dependent on the doping concentration, which reaches the optimal value as the doping concentration is 0.4mol%. These results suggest that this kind of material may have potential application as a multifunctional device by integrating its excellent upconversion luminescence and electrostrictive properties.

Electric dipole sheets inBaTiO3/BaZrO3superlattices

We investigate two-dimensional electric dipole sheets in the superlattice made of BaTiO$_{3}$ and BaZrO$_{3}$ using first-principles-based Monte-Carlo simulations and density functional calculations. Electric dipole domains and complex patterns are observed and the complex dipole structures with various symmetries (e.g. Pma2, Cmcm and Pmc2_{1}) are further confirmed by density functional calculations, which are found to be almost degenerate in energy with the ferroelectric ground state of the Amm2 symmetry, therefore strongly resembling magnetic sheets. More complex dipole patterns, including vortices and anti-vortices, are also observed, which may constitute the intermediate states that overcome the high energy barrier of different polarization orientations previously predicted by Lebedev\onlinecite{Lebedev2013}. We also show that such system possesses large electrostrictive effects that may be technologically important.

Large electrostrictive effect in ternary Bi0.5Na0.5TiO3-based solid solutions

In the present work, a ternary solid solution (0.935-x)Bi0.5Na0.5TiO3-0.065BaTiO3-xSrTiO3 (BNBST, BNBSTx) was designed and fabricated using the traditional solid state reaction method. A morphotropic phase boundary between the ferroelectric long-range-order and relaxor pseudocubic phases was determined around x of 0.22 for poled solid solutions. The further increase of SrTiO3 substitution turned the depolarization temperature Td to below ambient temperature and led to a sharp decrease in the remnant polarization Pr and quasi-static piezoelectric constant d33. A large electrostrictive coefficient Q of 0.026 m4 C−2 was obtained for BNBST0.30, which was entirely comparable to the well-known electrostrictive material Pb(Mg1/3Nb2/3)O3, recently reported Bi0.5Na0.5TiO3-BaTiO3-K0.5Na0.5NbO3, and Bi0.5Na0.5TiO3-BaTiO3-KNbO3. Under a moderate electric field of 4 kV/mm, the electrostrictive strain can reach as high as ∼0.11%. Furthermore, the electric-field-induced strain exhibited weak temperature-dependent behavior. The large electrostrictive strain was suggested to be ascribed to the formation of relaxor pseudocubic phase developed by the SrTiO3 substitution and the high electrostrictive coefficient of BNBST ceramics makes them great potential to be applied to the environmental-friendly solid-state actuators.