PbTiO3 Piezoelectric Ceramics Research Articles

Low‐temperature sintering Sm‐doped PMN–PZ–PT multilayer ceramic actuator with high strain and temperature stability

AbstractMultilayer ceramic actuators find extensive utility in applications requiring precise displacement control or force output, due to their advantages of high precision control, rapid response, low driving voltage, low power consumption, and so on. For practical applications, there is a need for high‐performance multilayer ceramic actuators (MLAs) that combine cost‐effectiveness, efficiency, and temperature stability. In this work, 1.5 mol%Sm‐doped 0.25 Pb(Mg1/3Nb2/3)O3–0.36PbZrO3–0.39PbTiO3 piezoelectric ceramics with PbO–CuO as sintering aid were fabricated. The addition of PbO–CuO significantly reduced the sintering temperature by 300°C, while having minimal impact on the piezoelectric properties. The optimized sintering condition, achieved at a low sintering temperature of 950°C with the introduction of a tiny 0.4 wt% sintering aid, yields impressive piezoelectric strain coefficient d33* = 690 pm/V. This substantiates the viability of employing low‐cost Ag/Pd (90/10) as inner electrode, which can be co‐fired with ceramic layer to fabricate MLA. This innovation enables a remarkable displacement of 1 µm at a low driving voltage of 200 V across a 9‐layers piezoelectric actuator, accompanied by high‐temperature stability, exhibiting <20% variation over the temperature range of 30–250°C. These results underscore a great potential for high‐performance piezoelectric actuators over a broad temperature range.

Quantitative domain evaluation in rhombohedral BS-PT piezoelectric ceramics via diffraction-plane-transformation model

The domain structure fundamentally determines the piezoelectric/ferroelectric performance of ferroelectric materials. To understand the correlation between macro-properties and microstructure, the evolution of domain structure should be clearly figured out. Here, the diffraction-plane-transformation (DPT) model is proposed for the domain evaluation in BS-PT piezoelectric ceramics of rhombohedral crystalline structure. The transformation between different crystal planes is accurately revealed by the DPT model. Then, non-180° domain reversal in rhombohedral 0.4BiScO3–0.6PbTiO3 piezoelectric ceramics (abbreviated as BS-PT) can be quantitatively estimated, whether in electric poling or thermal depoling processes. Experimentally, the correlations between piezoelectric coefficients, electromechanical coupling properties, and non-180° domain reversal percentage are investigated. It is proven that the DPT model provides an effective method for the non-180° domain estimation in rhombohedral crystalline ceramics.

Mn-doped 0.15Pb(Yb1/2Nb1/2)O3–0.48Pb(Mg1/3Nb2/3)O3–0.37PbTiO3 piezoelectric ceramics for high performance high-power transducers

For high-power transducer applications, the piezoelectric materials should fulfill specific requirements of a high mechanical quality factor (Qm), a high piezoelectric strain coefficient (dij), and a high Curie phase transition temperature (Tc). In this study, we present an investigation of the structural, piezoelectric, and high-power characteristics of Mn-doped 0.15Pb(Yb1/2Nb1/2)O3–0.48Pb(Mg1/3Nb2/3)O3–0.37PbTiO3 (0.15PYN–0.48PMN–0.37PT) ceramics. The introduction of Mn dopants led to an increase in the tetragonal phase fraction within the 0.15PYN–0.48PMN–0.37 PT ceramics and the formation of oxygen vacancies, consequently significantly enhancing Qm due to their synergistic effect. Despite the hardening effect, the high value of the piezoelectric coefficient (d33) was maintained due to the increase in grain size. Particularly, the specimen doped with 3 mol% of Mn exhibited excellent piezoelectric properties of d33 = 345 pC/N, Qm = 1159, and Tc = 207°C. This specimen displayed a high vibration velocity of 0.6 m/s under the condition of equilibrium ΔT < 20°C (temperature rise from initial temperature), thereby confirming its immense potential for high-power transducer applications.

Outstanding unipolar strain of textured Pb(Mg1/3Nb2/3)O3–PbZrO3–PbTiO3 piezoelectric ceramics manufactured by particle size distribution control of the plate-like BaTiO3 template

High-strain piezoelectric ceramics are required to miniaturize actuators for use in machinery and electronic systems. This paper reports an ultra-high strain of textured Pb(Mg1/3Nb2/3)O3–PbZrO3–PbTiO3 (PMN–PZ–PT) ceramics prepared using a plate-like BaTiO3 (BT) template. Small BT particles (<5 µm), which are difficult to orient as desired during tape casting, were removed from the as-synthesized BT (as-BT) template via a simple sedimentation method. Then, the residual BT (rs-BT) was used to prepare textured PMN–PZ–PT ceramics, which were compared with the textured ceramics prepared using the as-BT. Results show that the textured 0.4PMN–0.22PZ–0.38PT ceramics prepared with 5 vol% of rs-BT yield a significantly enhanced unipolar strain of 0.26% at 2 kV mm−1, when compared to the strain of 0.21% obtained from the textured 0.4PMN–0.22PZ–0.38PT ceramics prepared with the same amount of as-BT.

Templated grain growth of Bi(Zn0.5Zr0.5)O3 modified BiScO3−PbTiO3 piezoelectric ceramics for high temperature applications

ABSTRACT 2.5Bi(Zn0.5Zr0.5)O3−37.5BiScO3−60PbTiO3 (BZZ-BS-PT) ceramics were successfully textured in the [001] by templated grain growth (TGG) process using 5 vol% <001>-oriented BaTiO3 (BT) plate-like templates. The templates were aligned in the matrix powder via tape casting and textured BZZ-BS-PT ceramics sintered at 1100°C for 3 h in air had a relative density of 98% and a Lotgering factor of 0.91. Chemically stable BT templates in Pb and Bi-rich BZZ-BS-PT system gave rise to the formation of highly oriented polycrystalline structure with larger block-like grains. A very high unipolar strain of 0.3% and low-field (<5 kV/cm) piezoelectric charge coefficient (d33) of 930 pm/V when driven at 50 kV/cm were achieved in highly textured ceramics together with a Curie temperature (T C) of 403°C. The TGG approach significantly improved piezoelectric properties of the BZ-BS-PT ceramic system without deteriorating the dielectric properties, which is a very promising high-performance candidate for high-temperature sensor, transducer and actuator applications.

Electrical properties and temperature stability of high TC/TR-T Pb(In1/2Nb1/2)O3–Pb(Zn1/3Nb2/3)O3–PbTiO3 piezoelectric ceramics with compositions near the morphotropic phase boundary

Three sets of ternary ceramics in the compositions of 0.35Pb(In1/2Nb1/2)O3–(0.65−y)Pb(Zn1/3Nb2/3)O3–yPbTiO3 (y = 0.22–0.29), 0.40Pb(In1/2Nb1/2)O3–(0.60–y)Pb(Zn1/3Nb2/3)O3–yPbTiO3 (y = 0.24–0.32), and 0.50Pb(In1/2Nb1/2)O3–(0.50–y)Pb(Zn1/3Nb2/3)O3–yPbTiO3 (y = 0.27–0.37) near the morphotropic phase boundary (MPB) were fabricated by a two-step solid-phase synthesis route. The structure, electrical properties, and temperature stability of piezoelectric ceramics were studied. Structural analysis revealed that all ceramics exhibited pure perovskite phase and dense microstructure. In our chosen compositions, the maximum piezoelectric coefficient d33 = 589 pC/N and electromechanical coupling factor kp = 0.59 are presented for 0.35PIN–0.40PZN–0.25PT, the highest rhombohedral to tetragonal phase transformation temperature TR-T on the order of 187 °C is observed in the 0.50PIN–0.23PZN–0.27PT composition with a Curie temperature TC = 269 °C, 0.40PIN–0.33PZN–0.27PT, and 0.40PIN–0.32PZN–0.28PT ceramics do not depolarize at temperatures up to 230 °C. Considering the relatively high TC (255 °C), d33 (523 pC/N) and good thermal stability, 0.40PIN–0.33PZN–0.27PT is very promising for high-temperature piezoelectric applications. On this basis, a property-composition diagram around MPB in PIN–PZN–PT system was also established.

Preparation and characterization of pyrochlore-free 0.655Pb (Mg1/3Nb2/3)O3-0.345PbTiO3 piezoelectric ceramics by tape-casting process

Piezoelectric ceramics of the perovskite solid solution 0.655Pb (Mg1/3Nb2/3)O3-0.345PbTiO3 (0.655PMN-0.345PT) were synthesized by tape-casting process. Highly dense ceramics lacking parasitic pyrochlore phases were fabricated by using precursor method and adding moderate PbO. The influences from sintering temperature on the physical and electrical properties of the 0.655PMN-0.345PT ceramics were initially investigated by phase and microstructure analyses. High piezoelectric, dielectric and ferroelectric properties of d33 = 700 pC/N, kp = 0.605, εr = 4770, tanδ = 0.016, Pr = 30.68 μC/cm2 were obtained for the specimens sintered at 1200 °C. Compared with the traditional solid-state sintering method, the performance of ceramics formed by tape-casting achieved an improvement.

Preparation and characterization of pyrochlore-free 0.655Pb(Mg1/3Nb2/3)O3-0.345PbTiO3 piezoelectric ceramics by tape-casting process

Piezoelectric ceramics of the perovskite solid solution 0.655Pb(Mg1/3Nb2/3)O3-0.345PbTiO3 (0.655PMN-0.345PT) were synthesized by tape-casting process. Highly dense ceramics lacking parasitic pyrochlore phases were fabricated by using precursor method and adding moderate PbO. The influences from sintering temperature on the physical and electrical properties of the 0.655PMN-0.345PT ceramics were initially investigated by phase and microstructure analyses. High piezoelectric, dielectric and ferroelectric properties of d33=700 pC/N, kp=0.605, εr=4770, tanδ = 0.016, Pr=30.68 μC/cm2 were obtained for the specimens sintered at 1200 °C. Compared with the traditional solid-state sintering method, the performance of ceramics formed by tape-casting achieved an improvement.

Dielectric polarization and electrical properties of Modified PbTiO3 Piezoelectric Ceramics for high frequency transducer applications

PbTiO3 ceramics which modified by chiral symmetry material LiYW2O8 for the applications of high frequency transducers or actuators were investigated. The densification test results show that the LiYW2O8 modified PbTiO3 ceramics have good sintering properties at 900 °C. The dipole relaxation of PbTiO3 ceramics occurred at around 107 Hz, the difference of dipole relaxation time between polarized and unpolarized sample shows strong correlation with the piezoelectric constant. The d33, K33, and Np are close related to Tetragonality. The Tetragonality is higher, the value of d33, and K33 are also higher, and the value of Np is lower. The PbTiO3-0.35wt.% LiYW2O8 ceramic shows the relatively good properties of 68 pC/N and 245.4 for d33 and K33, respectively, which can meet the applications of high frequency transducers.

Phase transition and thermal depolarization of double perovskite modified low sintering temperature PbTiO3 piezoelectric ceramics

Phase transition and thermal depolarization of PbTiO3 piezoelectric ceramics with Double Perovskite modified were investigated. With 5mol% Double Perovskite (BFM, BNM, YNM, SNM), the PbTiO3 has a possibility to change the crystal structure to a large extent, and the sintering temperature can be controlled below 960°C. With increasing ionic radius difference between addition and PbTiO3, the crystal structure of modified PbTiO3, measured by synchrotron radiation changed from Tetragonal (P4mm) to Orthorhombic (Pmm2) and became more ordered (from 2×2×1 super cell to 6×2×2 super cell). The ordered Orthorhombic structure PT has higher phase transition temperature (496–540°C) than the Tetragonal PT (481°C). All modified PbTiO3 ceramics show high depolarization temperature. The depolarization temperatures of PT-BFM, PT-BNM, PT-YNM, and PT-SNM are 470°C, 480°C, 495°C, and 505°C, respectively.

Enhanced high-field strain and reduced high-temperature dielectric loss in 0.6(Bi0.9La0.1)(Fe1−xTix)O3–0.4PbTiO3 piezoelectric ceramics

0.6(Bi0.9La0.1)(Fe1−xTix)O3–0.4PbTiO3 (BLFT–PT) (x=0, 0.01, 0.02, and 0.04) ceramics were prepared by traditional solid state reaction method. XRD results indicate that BLFT–PT ceramics show the coexistence of rhombohedral and tetragonal phases, and the c/a ratio as well as the fraction of rhombohedral phase decrease with increasing Ti content. Values of the dielectric constant εr, dielectric loss tanθ at 1kHz, Curie temperature Tc, and piezoelectric constant d33 for BLFT–PT ceramics with the composition of x=0.02 were of 682, 0.032, 450°C, and 117C/N, respectively. It is interesting that the maximum strain of BLFT–PT ceramics achieves about 0.2% under the electric field of 120kV/cm, which is twice of that for BLF–PT ceramics without Ti modification and comparable with that of BiScO3–PbTiO3 ceramics. The high temperature dielectric loss was reduced significantly by Ti doping, which was only one tenth of BLF–PT ceramics in the temperature range of 200–400°C. Impedance spectroscopy analysis reflectsthat Ti doping may enhanc the grain resistivity by reduced defect concentration, and thus cause the resistivity of BLFT–PT to increase obviously at elevevated temperatures. These results indicate that BLFT–PT ceramics would be promising candidates for high temperature piezoelectric applications.

Pb(Mg1/3Nb2/3)O3–PbTiO3 Textured Ceramics with High Piezoelectric Response by a Novel Templated Grain Growth Approach

Pb(Mg1/3Nb2/3)O3–PbTiO3 is used as a model system of perovskite solid solutions with very high piezoelectric response at tailored morphotropic phase boundaries to demonstrate the processing of textured ceramics by ceramic‐only technology. A novel homogeneous templated grain growth approach that uses conventional ceramic procedures and a single‐source nanocrystalline powder for the matrix and also for obtaining the templates is described. Two batches of (100) faceted cube‐shaped microcrystals with average sizes of 27 and 10 μm were successfully used as templates, and aligned by tape casting for the processing of &lt;001&gt;‐textured Pb(Mg1/3Nb2/3)O3–PbTiO3 piezoelectric ceramics. Materials with effective piezoelectric coefficients up to 1000 pC/N and ferroelectric properties approaching those of single crystals are obtained.

Sintering and electrical properties of Nb5+ doped 0.63Bi(Mg1/2Ti1/2)O3–0.37PbTiO3 piezoelectric ceramics

Nb5+ doped 0.63Bi(Mg1/2Ti1/2)O3–0.37PbTiO3 (0.63BMT–0.37PT + xNb5+) ceramics have been fabricated by means of citrate sol–gel method and ordinary sintering. Effects of Nb5+ doping on the densification and various electrical properties were studied. The results indicated that the addition of a small amount of Nb5+ gradually changes the crystal structure from a typical rhombohedral-tetragonal coexisted structure to a nearly pure rhombohedral structure. A slight amount of secondary phases start to appear as the doping content of Nb5+ is more than 1.5 mol%, indicating that the solubility limit of Nb5+ in the matrix composition is reached. Moreover, electrical properties of the sintered ceramics were obviously changed based on the effect of densification and ionic substitution. 0.63BMT–0.37PT + 0.005Nb5+ ceramics sintered at 1,020 °C exhibit optimum properties of piezoelectric constant d33 ~ 245 pC/N, planar electromechanical coupling factor kp ~ 30 %, \( \varepsilon_{33}^{\text{T}} /\varepsilon_{\text{o}} \) ~ 1,220, and Tc ~ 460 °C.

Effects of sintering atmosphere on microstructure and electrical properties of BiScO3–PbTiO3 high-temperature piezoceramics

BiScO3–PbTiO3 piezoelectric ceramics were fabricated by the conventional solid state reaction method. The effects of sintering atmosphere on microstructure and electrical properties of BiScO3–PbTiO3 were studied. Different weight changes were found in samples sintered in different atmospheres. X-ray diffraction analysis reveals that all the samples have perovskite structure and a second phase is observed in the samples sintered in sacrificial powders. EDS analysis suggests the second phase could be the compound containing Bi and Pb. Samples sintered in air show lower dielectric constant than those sintered in sacrificial powders, but a higher piezoelectric coefficient. The resisitivity of samples sintered in air is about one order of magnitude higher than that of those sintered in sacrificial powders. These results suggest a promising method to gain BiScO3–PbTiO3 high-temperature piezoceramics with excellent electromechanical properties.

Relationship between Nonlinear Piezoelectricity and Decrease of Mechanical Quality Factor in Pb(Mn1/3Sb2/3)O3–PbZrO3–PbTiO3 Piezoelectric Ceramics Driven at High Power

By changing the Pb(Mn1/3Sb2/3)O3 content and Zr/Ti ratio, Pb(Mn1/3Sb2/3)O3–PbZrO3–PbTiO3 (PMS–PZT) system piezoelectric ceramics having different nonlinear piezoelectricities were fabricated. The transient responses of the sample current and the vibration velocity at the sample end were simultaneously measured during high-power driving. Both mechanical quality factors, Qm, which were calculated from these two kinds of transient responses, changed similarly on the driving power scale. This indicates that the change in Qm when driven at a high power can be estimated from the transient response of the sample current. From the analysis of the experimental results of Qm, it was found that high-power driving induces a decrease in Qm more easily in the samples with larger nonlinear piezoelectric constants of third-higher term, ξD31.

Preparation of a modified (Pb,Ca)TiO3 piezoelectric ceramics with binary complex elements substitution in B-site

Preparation of a modified (Pb,Ca)TiO3 with (Zn1/2W1.2) (Ni1/2Nb1/2) substitution in B-site had been studied. Adding suitable amounts of MnCO3 in this modified PbTiO3 piezoelectric ceramics, the material performances could be improved further. Optimized fabricating procession had also been investigated. Study showed that the modified (Pb,Ca)TiO3 piezoelectric ceramics had large anisotropy high mechanical quality factor and curie temperature lower dielectric constant and loss. The microstructure of the ceramics and a kind of micro-domain had been observed by XRD and TEM.

High Power Transformer Employing Piezoelectric Ceramics

0.10Pb(Mn1/3Sb2/3)O3–0.47PbZrO3–0.43PbTiO3 piezoelectric ceramics in a single-layer transformer successfully produces a maximum available power of 11 W. This 42×10×1 mm piezoelectric transformer operates in a third order length expansion vibration mode, with a load impedance of 100 k Ω at the output terminal. Two types of ceramic fabrication have been tested: one using 5.5 m2/g specific surface area calcined powder sintered at 1100° C, the other using 2.0 m2/g specific surface area calcined powder sintered at 1300° C. While such ceramics are expected to be especially useful in multilayered structure transformers, as well, sintering at 1100° C would be preferred for multilayer designs because relatively low cost metals, such as Ag–Pd alloys, could be employed for the internal electrodes. With ceramics sintered at 1300° C, however, high cost metals such as Pt would have to be used.

Microstructure study of Sm, Mn-modified PbTiO3 piezoelectric ceramics by XRD profile-fitting technique

By using the X-ray diffraction profile-fitting technique, the microstructures of Sm, Mn-modified PbTiO3 piezoelectric ceramic discs, including ferroelectric domain sizes, microstrains, and their variations with the poling strength have been quantitatively investigated. The results manifest that the modified PbTiO3 ceramics contain a high density of domain walls due to the presence of finely-divided coherent domain structures (tens of nanometres in dimension). The poling treament can evidently influence the domain-size distribution, with a more homogeneous microstructure being developed; however, it simultaneously causes high anisotropic microstrains within the structure which, together with the high density of domain walls, is expected to be responsible for the unusual high electromechanical coupling properties possessed by this material.

AN X Ray Diffraction STUDY ON THE ULTRA-HIGH ELECT-ROMECHANICAL ANISOTROPY IN (Pb0.85Sm0.10)(Ti0.98Mn0.02)O3 PIEZOELECTRIC CERAMICS

XRD technique was employed to examine Sm-modified PbTiO3 piezoelectric ceramics with typical ultra-high electromechanical anisotropy. By introducing crystal plane orientation density ρ(hkl) and establishing wall translation model for 90°ferroelectric domain switching, a quantitative analysis and discussion on the domain texture change within the ceramic disks poled at various electric forces has been carried out. The results indicate that 90°domain walls in the modified PbTiO3 ceramics show a strong spatial orientation preference, and little changes in their orientation can result from poling treatment but noticeable wall displacement appears. Another noteworthy result is that the thickness electromechanical coupling coefficient Kt develops with poling field almost at the same pace as the orientation density gain △ρ(002) of the crystal plane (002).

Frequency spectra of resonant vibration in disk plates of PbTiO3 piezoelectric ceramics

The frequency spectra of resonant vibration in disk plates of PbTiO3 piezoelectric ceramics were observed for diameter to thickness ratio (r) of 5 to 30 near the fundamental thickness extensional mode. The observed spectra could be classified into three groups of thickness mode and two groups of radial mode. For comparison, theoretical spectra for isotropic disk plate were also calculated for various Poisson's ratios (σ) of disk material on the basis of Gazis and Mindlin's theory. The calculations showed that the theoretical radial mode spectra can be divided into a strongly σ-dependent group and a slightly dependent one, and also showed that the upper ends of terrace-type spectra appear as a straight line at the cutoff frequency in a large-r region and may be corresponded to the thickness extensional mode. In fact, the fitting of the upper-end spectra to the experimental thickness extensional mode by adjusting σ, gives not only qualitative agreement of all experimental spectra with the theoretical ones, but also the best quantitative agreement with the strongly σ-dependent theoretical spectra. Thus, all observed spectra can be predicted nearly completely from the theory of isotropic disk plate by selecting a suitable equivalent σ which is 0.18 for the present anisotropic disk.