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The increasing demands of device applications in harsh environments have led to higher expectations for temperature and pressure resistance in high-temperature piezoelectric materials. In order to understand the performance characteristics of BiScO3-PbTiO3 (BS-PT) high-temperature piezoelectric materials in practical device applications, this study focuses on analyzing the dielectric, piezoelectric, and ferroelectric properties of BS-64PT ceramics under uniaxial stress up to 150 MPa, as well as its electromechanical performance under a hydrostatic pressure of up to 400 MPa. As the uniaxial pressure increases, both the bias-field and large-signal piezoelectric coefficients exhibit a pattern of initially increasing and subsequently decreasing. Furthermore, the bias-field piezoelectric coefficient exceeds 450 pC/N and the large-signal piezoelectric coefficient surpasses 630 pC/N under uniaxial pressures below 100 MPa. This highlights their exceptional resistance to depolarization caused by uniaxial stress. To obtain more precise piezoelectric properties for BS-64PT ceramics in the 31 and 33 modes under hydrostatic pressure, the admittance fitting method was utilized. This method takes into account the significant losses at higher pressures. Within the pressure range of 0–400 MPa, the values of d33 and d31 for BS-64PT ceramics exhibited a minor change of 7.6% and 8%, respectively. These findings indicate that BS-64PT ceramics exhibit more stable piezoelectric properties under both uniaxial and hydrostatic pressures when compared to the majority of Pb-based perovskite-structured materials. The exceptional stability of piezoelectric properties in BS-PT ceramics can be primarily attributed to their elevated anisotropy energy or coercivity field compared to other perovskite-structured Pb(Mg1/3Nb2/3)O3 (PMN) / Pb(Zr,Ti)O3 (PZT)-based ceramics reported. [ABSTRACT FROM AUTHOR]

[001]-textured 0.4P(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3-0.5%MnO2 (Mn-PMN-PZT) ceramics were fabricated by templated grain growth using 2 vol. % BaTiO3 in this paper. Full matrices of dielectric (ɛij), elastic (sij, cij), and piezoelectric (dij) parameters were obtained by the resonance–antiresonance method. The dielectric constant ɛ33T of textured ceramics reaches 2600, which is four times that of random ceramics. Textured Mn-PMN-PZT ceramics exhibit high d33 = 984 pC/N and high k33 = 0.89, which is much larger than d33 = 223 pC/N and k33 = 0.70 of random ceramics. However, ɛ11T of ceramics decreases by about 30% after texturing, and the corresponding shear coupling coefficient k15 also decreases from 0.66 to 0.44, which may be due to the reduction in the angle between spontaneous polarization and transverse direction. Furthermore, the temperature stability of the textured ceramics was evaluated as well. The phase transition temperature TR−T was determined by the impedance method to be 120 °C. The textured Mn-PMN-PZT ceramic shows high temperature stability, which is better than PMN-PT. [ABSTRACT FROM AUTHOR]

In this work, [001] textured Sm0.025Pb0.9625(Mg1/3Nb2/3)0.74Ti0.26O3 (Sm-PMN-26PT) ceramics were synthesized by the templated grain growth method. The dielectric, piezoelectric, and electromechanical properties of untextured and textured ceramics are systematically studied. A high texture degree of 99% was obtained using 1% volume fraction of the BaTiO3 (BT) template. The textured ceramics exhibit an excellent piezoelectric coefficient d33 of 1882 pC/N at room temperature, and an extremely high d33* of 2510 pm/V is obtained. The dielectric, ferroelectric, and strain characteristics reveal that the improvement of piezoelectric properties of textured ceramics comes from the increase of dielectric constant ε33 and electrostriction coefficient Q33. Both the intrinsic response of the domain and the external contribution of the domain wall are enhanced in [001] textured ceramics, which may be the microscopic mechanism of increased piezoelectric activity. The Sm-PMN-26PT textured ceramics exhibit excellent piezoelectric properties, which are very promising for using at room temperature. [ABSTRACT FROM AUTHOR]

The electromechanical properties of [001]‐textured Mn‐PMN‐PZT ceramics are characterized under a hydrostatic pressure of up to 400 MPa. The dielectric constant of textured ceramics increases first and then decreases as pressure increases. A comparison of the electromechanical constants sij, kij, and dij (i, j = 1, 3) obtained by the method of direct calculation and admittance fitting is displayed in this work. The results show that the two methods can obtain similar results at lower pressures. When the pressure is relatively high, the loss cannot be ignored, and the results of the two methods are quite different. The admittance fitting method gives a more accurate piezoelectric constant. Under 400 MPa, textured ceramics have k31 = 0.55, d31 = 321 pC/N, k33 = 0.89, and d33 = 702 pC/N, while random ceramics have k31 = 0.33, d31 = 92 pC/N, k33 = 0.71, and d33 = 230 pC/N. The large piezoelectric properties of textured ceramics under high pressure make them potential underwater transducers. [ABSTRACT FROM AUTHOR]

Design of a projecting‐receiving dual‐purpose transducer is challenging due to the difficulty of synthesizing piezoelectric materials with combinatory "soft" properties (high piezoelectric coefficient d) and "hard" properties (low dielectric loss and high mechanical quality factor Qm). In this study, we provide a different perspective to address this challenge via exploiting single‐crystal‐like electrostriction coefficient Q33 through the fabrication of grain oriented or textured "hard" piezoelectric ceramics. Mn‐doped 0.27Pb(In1/2Nb1/2)O3–0.41Pb(Mg1/3Nb2/3)O3–0.32PbTiO3 (Mn:PIN–PMN–PT) piezoelectric ceramics with a high [0 0 1]c texture fraction of 99% were synthesized, which exhibit three times greater piezoelectric properties (d33 ∼ 828 pC/N) than random counterparts (d33 ∼ 251 pC/N), while maintaining low loss (tan δ ∼ 0.5%, Qm = 443). According to the formula d33=2Q33Prε33${d}_{{\mathrm{33}}}{\mathrm{\ = \ 2}}{Q}_{{\mathrm{33}}}\ {P}_{\mathrm{r}}\ {\varepsilon }_{{\mathrm{33}}}$, the large improvement of d33 in textured ceramics is mainly due to a doubling increase in dielectric constant ε33 and Q33 (∼0.057 m4/C2). Notably, the Q33 exhibits remarkable similarity to that of PMN–PT single crystals, further contributing to the enhanced piezoelectric performance of textured ceramics. Phase field model of ferroelectrics was performed to understand the texturing on Q33 and elucidate the underlying mechanism at the domain level. The textured ceramics exhibit excellent combinatory "soft" and "hard" properties, which are the promising materials for developing projecting‐receiving dual‐purpose transducers with high efficiency and high sensitivity. [ABSTRACT FROM AUTHOR]

Quenching from sintering temperature enhances the depolarization temperature (Td) in Na1/2Bi1/2TiO3-based ceramics without significant deterioration of piezoelectric properties (d33). In this work, quenching effects in an ergodic relaxor 0.97(0.94Na0.5Bi0.5TiO3–0.06BaTiO3)–0.03AgNbO3 (NBT–6BT–3AN) were investigated based on structure, ferroelectric, and dielectric properties. The ergodicity to nonergodicity transition was obtained by quenching NBT–6BT–3AN above 1000 °C. The temperature stability of the quenching-induced nonergodicity was examined by annealing the quenched sample at 300 °C and 600 °C. The effect of oxygen vacancy on ergodicity to nonergodicity transition was investigated by comparing ferroelectric and electrostrain responses of the quenched and nitrogen-atmosphere-annealed samples. The influence of quenching on the structure including the average crystal structure, phase fraction and lattice distortion and the local structure including bond lengths and ordering of ions was analyzed. The ergodicity to nonergodicity transition upon quenching is ascribed to the contribution of the off-centered Bi3+ ions and ordered local structure. [ABSTRACT FROM AUTHOR]

Cu2+ substituted K0.5Na0.5NbO3 ceramics at B-site K0.5Na0.5(Nb1−xCux)O3−3x/2 (KNNC) were prepared by a solid state method. The dielectric, ferroelectric properties and defect compensation mechanism were studied. With the concentration of Cu2+ increasing from 0.005 to 0.10, permittivity and dielectric loss decrease, but further increasing the concentration of Cu2+ increasing leads to the increment of permittivity and dielectric loss. All KNNC ceramics exhibit double hysteresis loop characteristics. When the doping concentration Cu2+ is low (x = 0.0075), the double hysteresis loop disappears at large electric field, nonetheless, when x = 0.015, it maintains the characteristics of the double hysteresis loop even under the high electric field. The corresponding mechanism is explained from the aspects of correlation between defect dipoles and polarization orientation. [ABSTRACT FROM AUTHOR]

Pb(Zr 0.5 Ti 0.5)O 3 (PZT) powders were synthesized from needle-like TiZrO 4 (TZO) precursors by topochemical molten salt synthesis. The effects of the flux types, the raw powder sizes and the synthesis temperatures on the resultant particle morphologies and phase structures of both TZO and PZT were investigated. Via optimizing the synthesis conditions, needle-like TZO with a smooth surface and needle-like PZT with a rough surface were obtained. Transmission electron microscopy (TEM) analyses unveiled that TZO possesses a single-crystal structure with the axial direction along the [010] crystallographic orientation, while PZT exhibits a polycrystalline structure with a discernible degree of misorientation. Notably, the synthesized needle-like PZT from TZO were observed to be unstable and could not induce oriented grain growth of Pb(Mg 1/3 Nb 2/3)O 3 -PbZrO 3 -PbTiO 3 (PMN-PZT) ceramics. This study reveals that improving the thermal stability of needle-like PZT seeds is one of the key factors for the templated grain growth in textured piezoelectric ceramics. • In this study, we used TMSS to synthesize needle-like PZT homogeneous seeds from needle-like TZO precursors. • TEM analyses unveiled that TZO possesses a single-crystal structure with the axial direction along the [001] orientation. • PZT exhibits a polycrystalline structure with a discernible degree of misorientation. • The texture growth of needle-like PZT seeds within PMN-PZT matrix powders was studied. [ABSTRACT FROM AUTHOR]

Na 0.5 Bi 0.5 TiO 3 -BaTiO 3 (NBT-BT)-based lead-free piezoelectric ceramics have been actively studied in recent years as a potential replacement for lead-based materials in ultrasonic applications. However, its relatively low thermal depolarization temperature (T d) is still an imperative obstacle hindering implementation in practical application. Recently, it was reported that quenching is an effective way to improve T d of NBT-based ceramics, but the essential mechanism is still unclear. In this study, 0.94Na 0.5 Bi 0.5 TiO 3 -0.06BaTiO 3 (NBT-6BT) ceramics were quenched in air and liquid nitrogen, and then annealed in oxygen and nitrogen atmospheres to explore the origin of enhanced depolarization temperature. The results from this study correlate the enhancement of T d to the residual stress, which induces a stable rhombohedral ferroelectric phase, thereby increasing the thermal depolarization temperature of NBT-6BT. Our results indicate that the residual stress is also an important factor influencing the electrical properties of quenched piezoelectric ceramics, which should be given more attention in future studies. [ABSTRACT FROM AUTHOR]

In this study, the Pb(Yb 1/2 Nb 1/2)O 3 (PYN) relaxor with high Curie temperature (T C ∼300 °C) was incorporated into PbZrO 3 -PbTiO 3 (PZ-PT) ceramics to form 0.1PYN-(1- x)PZ- x PT ternary ceramics, and their phase compositions were systematically investigated, providing the more detailed phase diagrams, dielectric, piezoelectric, and ferroelectric properties. Excellent piezoelectric performance (d 33 ∼ 450 pC/N, d 33 * ∼714 pm/V), with high coercive field (E C ∼17.5 kV/cm) and T C (∼398 °C) were simultaneously achieved in the 0.1PYN-0.41PZ-0.49PT composition near the morphotropic phase boundary (MPB). The value of d 33 × E C , which exhibits higher than commercial PZT ceramics, indicates its suitability for high-field excitation devices. Additionally, the temperature stability of the resonant frequency (f r) is qualitatively studied by analyzing the main factors influencing f r from a theoretical perspective. Superior stability is achieved in the 0.1PYN-0.38PZ-0.52PT composition (T C ∼ 405 °C) with tetragonal phase, and the temperature coefficient of resonant frequency (Δ f r / f r 25 °C) remains within 0.5% up to 300 °C, far outperformance than previous reports. [ABSTRACT FROM AUTHOR]

Na 0.5 Bi 0.5 TiO 3 -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(0.94Na 0.5 Bi 0.5 TiO 3 -0.06BaTiO 3)-0.03AgNbO 3 (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 Na 0.5 Bi 0.5 TiO 3 -based ceramics. [ABSTRACT FROM AUTHOR]