BiScO3 PbTiO3 Research Articles

Broad bandwidth and excellent thermal stability in BiScO3-PbTiO3 high-temperature ultrasonic transducer for non-destructive testing

High-temperature ultrasonic transducer (HTUT) is essential for non-destructive testing (NDT) in harsh environments. In this paper, a HTUT based on BiScO3-PbTiO3 (BS-PT) piezoelectric ceramics was developed, and the effect of different backing layers on its bandwidth were analyzed. The HTUT demonstrates a broad bandwidth and excellent thermal stability with operation temperature up to 400 °C. By using a 10 mm thick porous alumina backing layer, the HTUT achieves a broad −6 dB bandwidth of 100 %, which is about 4 times superior to the transducer with an air backing layer. The center frequency (fc) of the HTUT remains stable with fluctuations of less than 10 % across the temperature range from room temperature to 400 °C. The HTUT successfully detected simulated defects in pulse-echo mode for NDT over 200 °C. This research not only advances high-temperature ultrasonic transducer technology but also expands the NDT applications in harsh environmental conditions.

Electromechanical properties of BS-PT ceramics under uniaxial pressure and hydrostatic pressure

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.

Phase structure of the ceramic samples of the BiScO3–PbTiO3–PbMg⅓Nb⅔O3 system near the morphotropic phase boundary studied by the Rietveld method

Abstract An X-ray diffraction study of ceramic samples of the BiScO3–PbTiO3–PbMg⅓Nb⅔O3 system with compositions close to the morphotropic phase boundary was carried out at room temperature. The existence of wide areas of solid solutions has been established. The symmetry of the PbTiO3-based solid solutions is tetragonal (space group P4mm). The symmetry of the PbMg⅓Nb⅔O3-based solid solutions is cubic (space group Pm3‾m). Near the BiScO3 side, the solid solutions are rhombohedral (space group R3m). During the morphotropic phase transition from the cubic solid solutions to the tetragonal ones, additional phases appear. If a tetragonal phase prevails ((1 − 2x)BiScO3–xPbTiO3–xPbMg⅓Nb⅔O3 x = 0.46; (1 − 2x)BiScO3–1.1xPbTiO3–0.9xPbMg⅓Nb⅔O3 x = 0.45 and 0.42), a satisfactory model is a model with a minority cubic phase (space group Pm3‾m). If a cubic phase prevails ((1 − 2x)BiScO3–1.1xPbTiO3–0.9xPbMg⅓Nb⅔O3 x = 0.39 and 0.36; (1 − 2x)BiScO3–0.8xPbTiO3–1.2xPbMg⅓Nb⅔O3 x = 0.4), a model with a minority monoclinic phase (space group Cm) or with two minority phases: tetragonal (space group P4mm) and monoclinic (space group Cm) is satisfactory.

Simultaneously Achieving Large Piezoelectricity and Low Dielectric Loss in High-Temperature BiScO3-PbTiO3-Based Ceramics.

High-temperature piezoelectric materials are pivotal to technology applications fields including defense, aerospace, nuclear energy, and oil well logging. However, the acquisition of excellent piezoelectric properties is usually at the cost of temperature stability (reduced Curie temperature and increased high-temperature dielectric loss), which hinders the application of piezoelectric ceramics in harsh environments. In this study, we investigated the effect of Nb5+ donor and Mn2+/3+ acceptor doping on the dielectric and piezoelectric properties of BiScO3-PbTiO3 (BS-PT)-based ceramics. In contrast to the acceptor doping, it was found that the donor doping not only enhances the piezoelectric properties but also effectively suppresses the dielectric loss at a high temperature by reducing the oxygen vacancy concentration. Eventually, we simultaneously attained an excellent piezoelectric performance (d33 is 553 pC/N at room temperature and 1528 pC/N at 400 °C, respectively) and a low dielectric loss (less than 2% in the temperature range of 150-300 °C) but still with a high Curie temperature (TC ∼ 445 °C) in Nb5+-doped BS-PT ceramics. Furthermore, different in situ measurements were used to demonstrate the remarkable temperature stability up to a high depolarization temperature of ∼400 °C. This work represents significant progress in high-temperature piezoelectric materials and provides a guideline for future efforts on enhancing the piezoelectricity and suppressing the dielectric loss at high temperature.

In-situ measurement of thermal depolarization in tetragonal BS-PT piezoelectric ceramics

High temperature depolarization poses a significant challenge to the practical application of piezoelectric/ferroelectric materials. Determining the depolarization temperature (Td) in such materials is crucial for evaluating their performance under high temperature conditions. Here, we propose a method for observing thermal depolarization by examining the 90º domain switching induced strain. Our results show that the differential thermal expansivities of unpoled and poled tetragonal BiScO3-PbTiO3 (BS-PT) piezoelectric ceramic samples can distinguish between thermal expansion strain and 90º domain switching induced strain. The effectiveness of our proposed method is further confirmed by quantitatively analyzing the 90º domain via X-ray diffraction. Compared to the in-situ resonance-antiresonance impedance spectrum, our method allows for more accurate testing of depolarization temperature, demonstrating significant potential for the direct observation of thermal depolarization in piezoelectric/ferroelectric materials.

Enhanced electromechanical properties and thermal stability of antimony-modified BiScO3-PbTiO3 high-temperature piezoelectric ceramics

The search for a suitable donor dopant to improve the piezoelectric response of BiScO3-PbTiO3 (BS-PT) piezoelectric ceramics without sacrificing temperature stability is crucial for developing high-temperature piezoelectric materials for the application in the elevated temperature. In this study, the effects of Sb5+ donor doping on the microstructure, dielectric, ferroelectric, piezoelectric and electromechanical properties of the BS-PT ceramics were investigated. It was found that the Sb5+ dopant acts as the grain growth inhibitor, resulting in a dense and fine-grain microstructure. An enhanced piezoelectric properties d33 of 535 pC N−1 with a high Tc of 440 °C was simultaneously achieved in 0.25 mol%Sb5+ doped BS-PT (BSPT-0.25Sb) ceramic. The results of in-situ piezoelectric constants and electromechanical coupling coefficients as a function of temperature indicate that the BSPT-0.25Sb ceramic has a high depolarization temperature Td of 400 °C, which is much higher than those of the most widely used PZT-based piezoelectric ceramics. Furthermore, BSPT-0.25Sb ceramic has much higher resistivity and lower dielectric loss than PZT-4 and PZT-8 at high temperature. The excellent piezoelectric properties and thermal stability of the BSPT-0.25Sb ceramic indicate that it is a promising piezoelectric material for high-temperature applications.

Synthesis of a nitrogen doped reduced graphene oxide based ceramic polymer composite nanofiber film for wearable device applications

In this study, piezoelectric composite nanofiber films were fabricated by introducing nitrogen-doped-reduced-graphene-oxide as a conductive material to a P(VDF-TrFE) polymer and a BiScO3–PbTiO3 ceramic composite employing an electrospinning process. Nitrogen was doped/substituted into rGO to remove or compensate defects formed during the reduction process. Electro-spinning process was employed to extract piezoelectric composite nanofiber films under self-poling condition. Interdigital electrodes was employed to make planner type energy harvesters to collect electro-mechanical energy applied to the flexible energy harvester. From the piezoelectric composite with interdigital electrode, the effective dielectric permittivity extracted from the conformal mapping method. By introducing BS–PT ceramics and N-rGO conductors to the P(VDF-TrFE) piezoelectric composite nanofiber films, the effective dielectric permittivity was improved from 8.2 to 15.5. This improved effective dielectric constant probably come from the increased electric flux density due to the increased conductivity. Fabricated interdigital electrode using this thin composite nanofiber film was designed and tested for wearable device applications. An external mechanical force of 350 N was applied to the composite nanofiber-based energy harvester with interdigital electrodes at a rate of 0.6 Hz, the peak voltage and current were 13 V and 1.25 μA, respectively. By optimizing the device fabrication, the open-circuit voltage, stored voltage, and generated output power obtained were 12.4 V, 3.78 V, and 6.3 μW, respectively.

High piezoelectricity with broad temperature insensitivity in BiScO3–PbTiO3‐based piezoceramics

AbstractThe surge of interest in searching for high‐temperature piezoceramics has proved that BiScO3–PbTiO3 ceramics with high piezoelectric constant and high Curie temperature are promising for high‐temperature nondestructive inspection (NDT) applications. However, their inferior temperature stability limits the applications. In this paper, 0.365BiScO3–0.635(Pb1‐3x/2Bix)(Ti0.99Zn0.01)O3 (BS–xBPZnT) system has been investigated by doping Bi ions to A‐site and Zn ions to B‐site based on the lattice distortion and hybrid orbital theory. The transformation of domain structures has been achieved, which is varied from typical strip‐like domains to complex configuration of micro‐domain. Meanwhile, the morphotropic phase boundary (MPB) was constructed in this system. The results indicated that x = 0.01 composition can reach high piezoelectric coefficient (d33) of 490 pC/N and high Curie temperature of 428°C. Besides, the in situ high‐temperature d33 results show that x = 0.01 sample can keep stable from 50°C to 350°C, and its depolarization temperature is 410°C. The in situ high‐temperature XRD and PFM results show that the temperature stability of phase structure and domain structure is the key factor to improve the stabilization of d33. This work confirms that BS–xBPZnT ceramics have superior potential for high‐temperature application, paving a significant step toward enhancing the thermal stability of high‐temperature piezoceramics.

AC Conductivity and Dielectric Properties of BiScO3–PbTiO3 Piezoelectric Ceramics

Bi-based BiMeO3 (where Me is a transition metal) has been extensively studied owing to its outstanding ferroelectric properties. The dielectric and electrical properties of piezoelectric ceramics can be enhanced by the addition of Bi-based materials such as BiAlO3, BiScO3 , and Bi(Mg, Ti)O3. Among them, BiScO3–PbTiO3 ceramics have shown excellent piezoelectric properties and temperature stability near the morphotropic phase boundary (MPB) region. Meanwhile, it is important to study the electrical properties of piezoelectric materials such as dielectric permittivity, conductivity of ferroelectric compounds, since dielectric and conductivities are related to pyroelectricity and piezoelectricity. In this study, the AC conductivity and dielectric properties of BiScO3–PbTiO3 ceramics were investigated with a wide range of frequencies and temperatures. Especially,the effect of PbTiO3 content on dielectric behavior of the BiScO3–PbTiO3 system was intensively studied by impedance spectroscopy.

Correlation between the grain size and phase structure, electrical properties in BiScO3‐PbTiO3‐based piezoelectric ceramics

AbstractAs one of the most promising candidates of high‐temperature piezoelectric sensors, BiScO3‐PbTiO3 (BS‐PT)‐based ceramics are commonly modified by end‐member substitution to modify the phase structures and electrical properties. In this work, BS‐PT‐based piezoelectric ceramics with various grain sizes (1.4‐3.7 μm) of the composition 0.98(0.36BiScO3‐0.64PbTiO3)‐0.02Bi(Sn1/3Nb2/3)O3 were prepared by conventional solid‐state reaction method at different sintering temperatures from 1100℃ to 1180℃. X‐Ray diffraction results show that the tetragonal phase content increases from 68.9% to 85.7% with the increasing sintering temperature. Transmission electron microscope characterizations reveal that micromorphology and domain morphology are sensitive to grain size. In addition, the dielectric and ferroelectric properties are almost independent on the sintering temperature, whereas an optimal piezoelectric constant d33 of 450 pC/N is achieved when the sintering temperature is 1120℃, which can be due to the suitable coexistence of the rhombohedral and tetrahedral phase, as well as the coexistence of nanodomains and subsize strip‐like domain. All of the results not only open a new window to improve d33 of piezoelectric ceramics but also help to further understand microstructure‐property relationships in piezoelectric ceramics.

Meso- to nano-scopic domain structures in high Curie-temperature piezoelectric BiScO3–PbTiO3 single crystals of complex perovskite structure

Multi-scale domain structures in the BiScO3–PbTiO3 single crystal are imagined and analyzed by birefringence imaging microscopy (BIM) and piezoresponse force microscopy (PFM), revealing the local distortion in the vicinity of the domain walls.

Phase evolution and relaxor behavior of BiScO3–PbTiO3–0.05Pb(Yb1/2Nb1/2)O3 ternary ceramics

High-temperature piezoelectric ceramics (0.95 − x)BiScO3–xPbTiO3–0.05Pb(Yb1/2Nb1/2)O3 (BS–xPT–PYN, x = 0.56–0.64) were prepared by a conventional solid-state reaction method. X-ray diffraction and Raman spectra demonstrated that the ceramics convert from monoclinic phase (x ≤ 0.58) to tetragonal phase (0.62 ≤ x ≤ 0.64). A phase coexistence of monoclinic and tetragonal in the vicinity of the MPB (x = 0.60) enhances the ferroelectric polarizability by a dynamical conversion between two energy-degenerate states with d33 = 392 pC/N, kp = 53.3% and Pr = 38.8 μC/cm2 and the operation temperature up to ~ 400 °C. Relaxor behaviors, which following the V–F law, are presented in this system and their dipole activation energy decrease for higher component x. The phase fraction versus temperature of the MPB (x = 0.60) was investigated by an in situ XRD, which gives an insight into the origin of the high-temperature piezoelectricity.

Building high transduction coefficient BiScO3–PbTiO3 piezoceramic and its power generation characteristics

Improving the power generation characteristics of piezoelectric energy harvesters requires the construction of piezoelectric ceramics with high transduction coefficient (d33 × g33), which remains a big challenge. In this paper, guided by piezoelectric energy harvester applications, the relationship between the composition, microstructure and transduction coefficient of (1 − x)BiScO3–xPbTiO3 material is systematically studied. The results demonstrated that the sample with a composition of x = 0.64 not only has a high Curie temperature (426 °C) which is beneficial to improve the working stability of the device, but also has a very high d33 × g33 value (15,110 × 10−15 m2/N), which is significantly superior to the commercial PZT system. Excellent electrical performance can be attributed to the fact that the composition of x = 0.64 located near MPB has a very high piezoelectric charge constant (505 pC/N) at the same time with moderate dielectric constant (1907). The cantilever-type energy harvester made of optimized composition generated a high output power density of 2.93 μW/mm3 at room temperature, which charged a commercial 47 μF electrolytic capacitor to 22 V in just 220 s and lighted up 72 LEDs for 0.1~0.2 s. Further, x = 0.64 harvester exhibited a large output voltage of 2.76 V even at 350 °C, suggesting its potential use for powering high temperature wireless sensors.

Effect of Pb(Mn1/3Sb2/3)O3 addition on the electrical properties of BiScO3-PbTiO3 piezoelectric ceramics

The BiMeO3-PbTiO3 (Me = Sc3+, In3+, Yb3+) systems are thought to have remarkable advantage in their Curie temperature in comparison with other perovskite ferroelectric materials. Among them, the BiScO3-PbTiO3 (BS-PT) solid solution with high Curie temperature (450 °C) and excellent piezoelectric coefficient is promising candidate for high temperature sensors and transducers application. Herein, we reported the effect of the addition of Pb(Mn1/3Sb2/3)O3 (PMS) on the electrical properties of BS-PT ceramics. The results showed that the temperature stability of BS-PT ceramics can be improved by the addition of a small quantity of PMS based on conjoint analysis of the temperature dependence of P-E hysteresis loops, leakage current density and kp. While the 0.03PMS-0.33BS-0.64 PT ceramics exhibited the optimal electrical properties at room temperature with the piezoelectric coefficient (d33) of 300 pC/N, the Curie temperature (TC) of 365 °C, the coercive field EC of 17 kV/cm, the dielectric constant εr of 1346, and dielectric loss tanδ of 0.74%. It was concluded that the temperature stability of the piezoelectric properties and the relaxor behavior were enhanced by the addition of PMS.

Tailoring Ferroelectric Properties of 0.37BiScO3–0.63PbTiO3Thin Films Using a Multifunctional LaNiO3Interlayer

Functional oxide thin films integrated into CMOS technology often exhibit degraded properties with respect to bulk materials because of complex interfacial phenomena. In this contribution, we demonstrate that a sol-gel LaNiO3 (LNO) interlayer deposited onto the surface of a Pt/TiO2/SiO2/Si substrate prior to growth of sol-gel BiScO3-PbTiO3 (BSPT) films acts: i) to seed nucleation of perovskite structured; ii) to template growth to give controlled orientation and enhanced crystallinity and iii) as a sink for oxygen vacancies (VO). The LNO interlayer therefore not only improves the ferroelectric, piezoelectric and dielectric properties but also reduces leakage current and prevents degradation of the remanent polarization during fatigue tests. We propose that the use of a LNO interfacial layer may offer a generic solution to interfacial degradation in functional oxide films.

Thermal stability of xBiScO3–(1-x-y)PbZrO3–yPbTiO3 ternary piezoelectric system with enhanced piezoelectric and dielectric properties

A xBiScO3–(1-x-y)PbZrO3–yPbTiO3 (denoted as xBS–(1-x-y)PZ–yPT) ternary piezoelectric system was prepared by combining BiScO3–PbTiO3 and PbZrO3–PbTiO3 for high-temperature applications. The morphotropic phase boundary region of the ternary system was identified by X-ray diffraction results together with piezoelectric and dielectric performance, which located at x = 0.054, y = 0.470; x = 0.072, y = 0.479; and x = 0.108, y = 0.492 composition intervals. Among all samples prepared, 0.072BS–0.449PZ–0.479PT displays the optimal piezoelectric and dielectric properties – piezoelectric coefficient d33 of 426 pC/N, relative dielectric constant εr of 1703, electromechanical coupling factor kp of 0.55, and Curie temperature Tc of 317°C. Additionally, this composition exhibits excellent thermal stability over a broad temperature range. Within the temperature range of 40–200°C (0.63Tc), variations in kp, mechanical quality factor Qm, and εr are 16.7% (Δkp/kp), 14.8% (ΔQm/Qm), and 5.22/°C (∂ε/∂T), respectively. The improved piezoelectric, dielectric properties and thermal stability is possibly attributed to the increasing number of irreversible non–180° domains that formed upon addition of BiScO3.

High temperature limitation due to onset of depoling in BiScO3–PbTiO3

Thermal depoling is investigated with impedance spectroscopy as a function of temperature and frequency for unmodified and ZnSc′ modified compositions around the morphotropic phase boundary (MPB) in the high temperature material (1−x)BiScO3–xPbTiO3 (BSPT). By tracking the shape and width of the fundamental resonance peaks and phase angle during impedance analysis, it was shown that the depoling temperature (Td), usually considered a single temperature, can actually be characterized as occurring over a range with an onset temperature (Tdonset) and a final temperature (Tdfinal). When this technique is applied to the rhombohedral compositions near the MPB of BSPT, it is seen that the peak narrowing in phase angle closely correlates to the rhombohedral-tetragonal phase transition decreasing from 350 °C to 300 °C when increasing from 58% to 62% PT. The Tdonset and the subsequent correlation to the phase transition are investigated further through aliovalent substitution of 1%, 2%, and 5% ZnSc in BS-PT. The Tdonset for the rhombohedral compositions displays enhancement over the unmodified compositions at ∼12 °C/1% ZnSc.

Point defect engineering of high temperature piezoelectric BiScO3–PbTiO3 for high power operation

BiScO3–PbTiO3 is used as a model system of BiMO3–PbTiO3 perovskite solid solutions with enhanced electromechanical response at ferroelectric morphotropic phase boundaries, and high Curie temperature to demonstrate specific point defect engineering for high power operation. The objective is to obtain a range of piezoelectric ceramics comparable to hard Pb(Zr,Ti)O3 materials, optimized for the different applications. In this work, a comprehensive study of Mn substitution for Sc is provided. Care is taken to isolate the effects of the point defects from those of concomitant structural and microstructural changes that have been previously described after MnO2 addition. Results strongly suggest that Mn substitution results in the formation of (MnSc′-VO) dipolar complexes that effectively clamp domain walls. This is the same mechanism responsible of hardening in Pb(Zr,Ti)O3. Indeed, Bi0.36Pb0.64Sc0.36-x MnxTi0.64O3 with x=0.02 is shown to be a high sensitivity piezoelectric with strongly reduced losses, suitable for high power operation between 200 and 400°C.

Enhanced Actuation Performance and Reduced Heat Generation in Shear-Bending Mode Actuator at High Temperature.

The actuation performance, strain hysteresis, and heat generation of the shear-bending mode actuators based on soft and hard BiScO3-PbTiO3 (BS-PT) ceramics were investigated under different thermal (from room temperature to 300 °C) and electrical loadings (from 2 to 10 kV/cm and from 1 to 1000 Hz). The actuator based on both soft and hard BS-PT ceramics worked stably at the temperature as high as 300 °C. The maximum working temperature of this shear-bending actuators is 150 °C higher than those of the traditional piezoelectric actuators based on commercial Pb(Zr, Ti)O3 materials. Furthermore, although the piezoelectric properties of soft-type ceramics based on BS-PT ceramics were superior to those of hard ceramics, the maximum displacement of the actuator based on hard ceramics was larger than that fabricated by soft ceramics at high temperature. The maximum displacement of the actuator based on hard ceramics was [Formula: see text] under an applied electric field of 10 kV/cm at 300 °C. The strain hysteresis and heat generation of the actuator based on hard ceramics was smaller than those of the actuator based on soft ceramics in the wide temperature range. These results indicated that the shear-bending actuator based on hard piezoelectric ceramics was more suitable for high-temperature piezoelectric applications.

High Electric‐Induced Strain and Temperature‐Dependent Piezoelectric Properties of 0.75BF–0.25BZT Lead‐Free Ceramics

0.75BiFeO3–0.25Ba(ZrxTi1−x) + 0.6 wt% MnO2 (0.75BF–0.25BZT) ceramics with Mn addition were prepared by the solid‐state reaction method. The high‐field strain and high‐temperature piezoelectric properties of 0.75BF–0.25BZT ceramics were studied. Introduction of Zr in the solid solutions decreased the Curie temperature slightly, and improved the dielectric and piezoelectric properties obviously. The piezoelectric properties of 0.75BZT–0.25BT ceramics reached the maximum at Zr content of 10 mol%. The Curie temperature Tc, dielectric constant ε and loss tanδ (1 kHz), piezoelectric constant d33, and planner electromechanical coupling factor kp of 0.75BF–0.25BZT ceramics with 10 mol% Zr were 456°C, 650, 5%, 138 pC/N, and 0.30, respectively. The high‐field bipolar and unipolar strain under an electric field of 100 kV/cm reached up to 0.55% and 0.265%, respectively, which were comparable to those of BiScO3–PbTiO3 and “soft” PZT‐based ceramics. The typical “butterfly”‐shaped bipolar strain and frequency‐dependent peak‐to‐peak strain indicated that the large high‐field‐induced strain may be due to non‐180° domain switching. Rayleigh analysis reflected that the improved piezoelectric properties resulted from the enhanced extrinsic contribution by Zr doping. The unipolar strain of 0.75BF‐0.25BZT ceramics with 10 mol% Zr was almost linear from RT to 200°C. These results indicated that 0.75BF–0.25BZT ceramics were promising candidates for high‐temperature and lead‐free piezoelectric actuators.