Ternary Piezoelectric Ceramics Research Articles

Structure evolution and enhanced electrical performance for BiScO3–Bi(Ni1/2Zr1/2)O3–PbTiO3 solid solutions near the morphotropic phase boundary

In this work, the Bi(Me)O3–PbTiO3-type (1-x-y)BiScO3-xBi(Ni1/2Zr1/2)O3-yPbTiO3 (BS-xBNZ-yPT) ternary piezoelectric ceramics have been prepared with x ≤ 0.075 by the traditional solid-state reaction methods. For compositions with x > 0.100, the Curie temperature (Tc) will reduce below 400 °C. X-ray powder diffraction results demonstrate the system a single perovskite phase structure. Analyzed the phase structure evolutions, it can be found the MPB of this BS-xBNZ-yPT ternary solid solutions shifts to the low PT content regions with the increasing BNZ content. Dielectric diffuse behaviour in this system may result from the production of polar nanodomains by the introduction of BNZ. The piezoelectric performance is enhanced with only a little decrease in Tc by the introduction of small content BNZ. The most promising composition BS-0.025BNZ-0.635PT exhibits the piezoelectric constant d33 of 480 pC/N, planar electromechanical coupling coefficients kp of 58.2%, and Curie temperature Tc of 439 °C, respectively. The unipolar strain was found up to 0.233% with the small strain hysteresis of 11.4%. All these properties together with the good thermal stability indicate the BS-xBNZ-yPT ceramics potential candidates for high temperature piezoelectric actuator application.

Phase transition and thermal stability of 5.4BiScO3−(94.6-x)PbZrO3−xPbTiO3 ternary system with excellent piezoelectric properties

The 5.4BiScO3−(94.6-x)PbZrO3−xPbTiO3 (43.0 < x < 51.0 mol%) ternary piezoelectric ceramics were synthesized by solid-state reaction method. Phase transition from rhombohedral to tetragonal structure was identified by X-ray diffraction. In combination with piezoelectric and dielectric properties, the morphotropic phase boundary (MPB) composition was confirmed in 5.4BiScO3−47.6PbZrO3−47.0PbTiO3 ceramic with optimal piezoelectric coefficient d33 of 474 pC/N, relative dielectric constant er of 1666, mechanical coupling factor kp of 0.64 and mechanical quality factor Qm of 415 at room temperature. Besides, the 5.4BiScO3−47.6PbZrO3−47.0PbTiO3 ceramic retained most of the piezoelectric properties in broad temperature range between 40 and 300 °C, which exhibited excellent thermal stability. There were only gentle variations in d33 (Δd33/d33 = 10.6%), kp (Δkp/kp = 14.1%), Qm (ΔQm/Qm = 10.3%), and er (∂e/∂T = 13.2/°C) at 300 °C, indicating BiScO3 doping in PbZrO3−PbTiO3 binary system could form a potential candidate for high temperature applications.

Enhanced piezoelectric properties in new ternary ceramics CuO-doped PSN-PMN-PT by low-temperature sintering

CuO-doped 15Pb(Sc1/2Nb1/2)O3-51Pb(Mg1/3Nb2/3)O3-34PbTiO3 (PSN-PMN-PT) ternary piezoelectric ceramics were synthesized by two-step columbite precursor method. The addition of CuO leads to full densification and well developed grain of the ceramics at a low sintering temperature of 950 °C. Meanwhile, the moderate CuO content significantly improves the phase transition temperature and piezoelectric properties. The optimal comprehensive properties are obtained in PSN-PMN-PT-0.125 wt%CuO ceramics: Tr-t = 120 °C, Tc = 185 °C, d33 = 518 pC/N, d33* = 853 pm/V, kp = 0.58, Pr = 27.8 μC/cm2, and Ec = 6.8 kV/cm. Moreover, excellent pyroelectric current temperature stability is also observed in this composition. These results indicate that low temperature sintered CuO doped PSN-PMN-PT ceramics are promising candidates for application multilayer piezoelectric devices and pyroelectric infrared detectors applications.

Large Electric Field-Induced Strain Response Under a Low Electric Field in Lead-Free Bi1/2Na1/2TiO3-SrTiO3-BiAlO3 Ternary Piezoelectric Ceramics

Bismuth-based lead-free ceramics are some of the most promising candidates for actuator applications due to their large strain response. Despite the large strains in bismuth-based piezoelectric ceramics, there still remain challenges regarding their utilization in practical applications. For instance, a relatively high operating field is required to obtain the large strain properties. In this work, lead-free Bi1/2Na1/2TiO3-SrTiO3-BiAlO3 (BNT-ST-BA) ternary piezoelectric ceramics are proposed as materials that could enhance the electromechanical strain performance under low driving field. We found that the highest normalized strain d33* value of 707 pm/V was achieved at a relatively low electric field of 3 kV/mm from 2 mol.% BA-modified BNT-ST ceramics. We suggest that the naturally induced nonergodicities in the ergodic relaxor generate internal stress. This induced internal stress is responsible for the excellent strain properties of this material. We believe that the materials synthesized in this study are promising candidates for actuator applications.

Structure, electrical properties and temperature stability of PIN–PZN–PT piezoelectric ceramics with morphotropic phase boundary compositions

A series of Pb(In[Formula: see text]Nb[Formula: see text]O3–Pb(Zn[Formula: see text]Nb[Formula: see text]O3–PbTiO3 (PIN–PZN–PT) ternary piezoelectric ceramics with compositions at the morphotropic phase boundary (MPB) were prepared. The phase structure, microstructure, electrical properties and temperature stability of PIN–PZN–PT ceramics were investigated systematically. The structural analysis indicated that an MPB phase consisting of rhombohedral and tetragonal phases was formed in all ceramics. For the selected compositions, dielectric measurements demonstrated that the Curie temperature [Formula: see text] changed from 237∘C to 295∘C and showed a strong trend of compositional dependence. All the samples showed good piezoelectic properties. Particularly, the 0.35PIN–0.40PZN–0.25PT sample has the optimum piezoelectric properties, the piezoelectric coefficient [Formula: see text] is 589 pC/N, the electromechanical coupling factors [Formula: see text] and [Formula: see text] are 59% and 49%, respectively. Compared with PZN–PT and PMN–PT ferroelectric crystals, the superior limit of usage temperature of PIN–PZN–PT ceramics was achieved around 230∘C by thermal depoling method. These results make PIN–PZN–PT ceramics a promising material to meet the practical demands of higher temperature and larger electric field operating ranges.

Synthesis and electrical properties of BNT-BKT-KNN lead free piezoelectric solid solution prepared via the combustion technique

ABSTRACTThe ternary piezoelectric ceramics of 0.77Bi0.5Na0.5TiO3-0.20Bi0.5K0.5TiO3-0.03K0.5Na0.5NbO3 (abbreviated as BNT-BKT-KNN) were prepared by the combustion technique. BNT-BKT-KNN powders were calcined between 600 and 850°C for 2 h and the BNT-BKT-KNN ceramics were sintered between 900 and 1050°C for 2 h. The results showed that a single phase of the sample is successfully obtained with a calcination temperature of 750°C for 2 h. The structure of the ceramics indicated the coexistence of rhombohedral and tetragonal phases. The maximum density 5.64 g/cm3 (95.0% of theoretical density), the highest shrinkage (16.4%) and optimum dielectric properties (ϵr∼1460 and ϵSA∼4081) were obtained from the sample sintered at 1025°C for 2 h. The dense sample also exhibited a fair ferroelectric properties (Pr = 12.5 µC/cm2 and Ec = 12.0 kV/cm) and good piezoelectric behavior (d33 = 164 pC/N).

Lead-free K0.5Na0.5NbO3–Bi0.5Li0.5ZrO3–BiAlO3 ternary ceramics: Structure and piezoelectric properties

Lead-free perovskite (0.995–x)(K0.5Na0.5)NbO3–x(Bi0.5Li0.5)ZrO3–0.005BiAlO3 ternary piezoelectric ceramics were projected and prepared by a conventional solid-state method. A research was conducted on the effects of (Bi0.5Li0.5)ZrO3 content on the structure and piezoelectric properties of the ceramics. By combining the X-ray diffraction patterns with the temperature dependence of dielectric properties, a rhombohedral–orthorhombic–tetragonal phase coexistence was identified for the ceramics with 0.02 ≤ x ≤ 0.025, and a rhombohedral–tetragonal phase boundary was determined in the composition x = 0.03. Upon further increasing the (Bi0.5Li0.5)ZrO3 content, the rhombohedral–tetragonal phase boundary transformed to a single rhombohedral structure with x ≥ 0.035. An obviously improved piezoelectric activity was obtained for the ceramics with compositions in and around the rhombohedral–tetragonal phase boundary, among which the composition x = 0.025 exhibited the maximum values of piezoelectric constant d 33, and planar and thickness electromechanical coupling coefficients (k p and k t), of 252 pC/N, 0.366, and 0.466, respectively. In addition, the ceramic with x = 0.025 was found to possess a relatively high Curie temperature of 368 °C, suggesting it may have a prospect for applications at elevated ambient temperatures.

Effect of MnO2 doping on piezoelectric, dielectric and ferroelectric properties of PNN–PZT ceramics

Traditional solid state reaction method was adopted to synthesize ternary piezoelectric ceramics 0.55Pb(Ni1/3Nb2/3)O3–0.45Pb(Zr0.3Ti0.7)O3 (abbreviated as PNN–PZT) with MnO2 additive (0−3.5% in molar ratio) in order to develop composition ceramics for low dielectric loss multilayer piezoelectric electroacoustic device. Effect of MnO2 doping on electric properties of PNN–PZT ceramics was systematically investigated. The results show that MnO2 doping significantly reduces dielectric loss (tgδ), increases phase transition temperature (Tmax) at a maximum value of relative permittivity, and weakens ferroelectricity. The 1.0mol% MnO2 doped PNN–PZT ceramics have optimal piezoelectric, dielectric and ferroelectric properties with d33=710 pC/N, kp=0.595, Qm=176, εr=3092 (1kHz), tgδ=0.0149 (1kHz), Pr=15.45 μC/cm2, and Ec=4.98kV/cm. A modified Curie–Weiss law revealed the behavior of diffuse relaxor phase transition of the ceramics. All these results (high d33, high kp, and low tgδ) make the modified PNN–PZT ceramics promising candidates for electromechanical devices. The mechanism of effect of MnO2 doping on electric properties was discussed.

Effects of sintering temperature on structure and properties of BY-PT-PMN ternary piezoelectric ceramics

Abstract

Enhanced piezoelectric properties of 0.55Pb(Ni1/3Nb2/3)O3-0.135PbZrO3- 0.315PbTiO3 ternary ceramics by optimizing sintering temperature

0.55Pb(Ni1/3Nb2/3)O3-0.135PbZrO3-0.315PbTiO3 (PNN-PZ-PT) ternary piezoelectric ceramics with excess 1.0 wt.% PbO were synthesized by the conventional solid-state reaction method at 1175–1300 °C for 2 h, respectively. The influence of sintering temperature (T s) on microstructure, piezoelectric, dielectric, and ferroelectric properties were systematically investigated. The results of XRD and Raman scattering spectra demonstrated that a typical perovskite structure with mainly rhombohedral symmetry near the MPB region were obtained for all the samples. The tetragonal phase content was increased slightly with the increase of sintering temperature. In addition, with increasing T s the average grain size increases while the density decreases were also found. The results of electrical measurements confirmed that piezoelectric constant, dielectric constant, remnant polarization were firstly increased and then decreased with the increase of sintering temperature. The optimum and remarkable enhanced electrical properties of d 33 = 1070 pC/N, k p = 0.69, e r = 8710, tanδ = 0.026, P r = 24.08 μC/cm2, and E c = 3.2 kV/cm were obtained for the sample sintered at 1250 °C for 2 h. Meanwhile, the sample exhibits a typical relaxor ferroelectric behavior with the maximum dielectric constant e m =24541 at Curie temperature T c = 113.3 °C at 1 kHz.

Effect of Fe doping on the structure and electric properties of relaxor type BSPT-PZN piezoelectric ceramics near the morphotropic phase boundary

The microstructure and electrical properties of Fe doped ternary complex piezoelectric ceramics 0.35BiScO3-0.6PbTiO3-0.05Pb(Zn1/3Nb2/3)O3-xFe (BSPT-PZN-xFe) with a composition near the morphotropic phase boundary were systematically investigated. The undoped BSPT-PZN showed a relaxor-like behavior. Addition of Fe largely reduced the diffuseness degree and improved the tetragonality. It also reduced the d33. The dielectric loss and the mechanical quality factor of the samples were, respectively, reduced and increased for about three times. The turning point in most of the parameters implies that the doping characteristics are mainly caused by the increased tetragonality (x<0.4mol%) or by the substitution induced defects (x>0.4mol%). Despite the complicated influence of Fe on the complex high temperature piezoelectric ceramics, it may still be used to significantly improve the ‘hardness’ of similar materials required for high power applications. Direct high temperature d33 measurements indicated a thermal depolarization temperature (250–260°C) much lower than the peak value temperature (Tm ∼410–440°C) in the temperature dependence of dielectric constant. This seems to be a challenge for the BSPT based ternary piezoelectric ceramics.

Piezoelectric properties of new ternary Bi1/2(Na, Li)1/2TiO3–(Bi1/2K1/2)TiO3–Ba0.85Ca0.15Ti0.90Zr0.10O3 ceramics

0.852[Bi1/2(Na1−xLix)1/2]TiO3–0.110(Bi1/2K1/2)TiO3–0.038Ba0.85Ca0.15Ti0.90Zr0.10O3 (BNLT–BKT–BCTZ-x) new ternary piezoelectric ceramics were fabricated by the conventional solid-state method, and their piezoelectric properties as a function of the Li content were mainly investigated. A stable solid solution with a single perovskite structure has been formed, and the depolarization temperature (Td) of these ceramics was identified by using the temperature dependence of the dielectric loss. The Td value of these ceramics gradually decreases, while the Tm value increases with increasing the Li content. The dielectric constant increases and the dielectric loss decreases with increasing the Li content, and an enhanced piezoelectric behavior of d33∼223 pC/N and kp∼35.2 % has been demonstrated in these ceramics with x=0.06.

Piezoelectric properties of PbHfO3–PbTiO3–Pb(Mg1/3Nb2/3)O3 ternary ceramics

Abstract(1 – x)Pb(Hf1–yTiy)O3–x Pb(Mg1/3Nb2/3)O3 (x = 0.1 ∼ 0.25, y = 0.555) ternary piezoelectric ceramics were prepared using the two‐step precursor method. Morphotropic phase boundary (MPB) compositions, located at x = 0.18 ∼ 0.22, were confirmed using X‐ray diffraction and by their dielectric, piezoelectric and ferroelectric properties. The optimum dielectric and piezoelectric properties were achieved for the MPB composition 0.8Pb(Hf0.445Ti0.555)O3–0.2Pb(Mg1/3Nb2/3)O3, with dielectric permittivity εr, piezoelectric coefficient d33, planar electromechanical coupling kp and Curie temperature TC being on the order of 2800, 680 pC/N, 70% and 276 °C, respectively. Of particular significance is that the new ternary ceramics exhibit comparable piezoelectric and electromechanical properties to commercial PZT5H ceramics, but with much improved TC, showing a potential for applications at elevated temperature. (© 2012 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Feature of morphotropic phase boundary of yBiGaO3–(1−x−y)BiScO3–xPbTiO3 high-temperature piezoelectric ceramics

y Bi Ga O 3 – ( 1 − x − y ) Bi Sc O 3 – x Pb Ti O 3 (BGSPT) ternary piezoelectric ceramics were fabricated by using conventional mixed oxide ceramic processing. It was found that the introduction of BiGaO3 into BiScO3–PbTiO3 system would cause a shift of morphotropic phase boundaries (MPBs), from x=0.64, y=0 to x=0.56, y=0.155; and an increase of Curie temperature (TC) near MPB, from 450 up to 494°C, respectively. BGSPT ceramics possessed higher TC (∼494°C) and high piezoelectric coefficient (d33∼180pC∕N), and showed the different rule of the Curie temperature near MPB versus the end member tolerance factor (t). The mechanism of higher TC in BGSPT system was also proposed.

Preparation of Pb(Zr,Ti)O3–Pb(Mg1/3Nb2/3)O3 piezoelectric ceramics by dry–dry method

Ternary perovskite ceramics of Pb[(Zr0.5Ti0.5)0.8−x(Mg1/3Nb2/3)0.2+x]0.98Nb0.02O3.01 (PZTMN, x = −0.075, −0.05, −0.025, 0, 0.025, 0.05, and 0.075 ), are synthesized via dry–dry method. B-site precursors of PZTMN ([(Zr0.5Ti0.5)0.8−x(Mg1/3Nb2/3)0.2+x]0.98Nb0.02O2.01, ZTMN) can be synthesized via a two-step solid state reaction method. The first calcination temperature is 1,300 °C, and the second is not higher than 1,360 °C. Incorporation of magnesium and niobium ions promotes the formation of the single phase solid solution with ZrTiO4 structure. Single phase perovskite PZTMN is formed at 780 °C, much lower than that in conventional process. Dense ceramics can be sintered at about 1,260 °C with dielectric and piezoelectric properties comparable to that of wet–dry method and higher than that of conventional method. It seems that B-site precursor method is cost effective in preparation of ternary piezoelectric ceramics.

Nonlinear Piezoelectric Coefficients in Compositions near Morphotropic Phase Boundary of PbZrO3-PbTiO3-Pb(Mg1/3Nb2/3)O3 Piezoelectric Ceramics

Linear and nonlinear piezoelectric coefficients of second- and third-higher terms in length-extensional vibration were experimentally investigated in the compositions near the morphotropic phase boundary (MPB) of PbZrO3-PbTiO3-Pb(Mg1/3Nb2/3)O3 ternary piezoelectric ceramics. The Zr/Ti ratio showing the maximum value of the piezoelectric constant d31 disagreed with that showing the maximum value of the electromechanical coefficient k31 in the transverse vibration. The disagreement increased with Pb(Mg1/3Nb2/3)O3 (PMN) content. The nonlinear piezoelectric coefficients of the second- and third-higher terms showed their minimum values at the Zr/Ti ratios showing the maximum values of d31. Hence, the Zr/Ti ratio showing the maximum value of d31 was regarded as the MPB composition. The nonlinear coefficients of the second- and third-higher terms on the MPB compositions showed different dependences on PMN content. The nonlinear coefficient of the second-higher term showed a grain size dependence in its change, and that of the third-higher term showed a mechanical quality factor dependence in its change. The difference in the dependences was discussed from the viewpoint of the difference in the occurrence mechanism of nonlinear phenomena dominating the two nonlinear coefficients.

Piezoelectric ceramic transformer

Abstract This paper presents a piezoelectric ceramic transformer which has a no-load alternating current voltage step-up ratio of about 150–200. The composition of the material is: ternary piezoelectric ceramics. The experimental results made on the material properties and the characteristics of transformer elements are presented. Based on the analysis of scanning electronic microscope and X-ray diffraction, the relations between physical properties and microstructure of piezoelectric ceramics were studied. With laser holography, under high voltage, the vibration modes of the transformer elements were measured. Amplitude distributions of vibration modes were quantitatively computed. The results were related with the voltage step up ratio. Analysis and comparison were made between vibration modes. The bar samples were used as transverse-type piezoelectric transformer elements. The specimens were made in disks of 8 × 0.8 mm and bars of 120 × 26 × 3 mm.