Lead Zirconate Titanate Piezoceramics Research Articles

Chemical modification of lead zirconate titanate piezoceramics through cold-sintering process

This study presents a facile strategy to chemically modify the PZT through the cold-sintering process. The presence of lead oxide phases in the XRD patterns of samples cold-sintered at 290 °C confirms the dissolution of Pb ions from the surface of PZT particles. Post-annealing the samples at 900 °C resulted in a phase pure material with a perovskite structure, wherein the Ba ions had diffused into the lattice of PZT. The post-annealed samples had a multi-faceted grain with equilibrated triple points and a relative density of ∼93%. The electromechanical characterization showed that the d33 of the samples increased with increasing content of Ba in the PZT, reaching a value of 201 ± 80 pm/V. The post-annealed samples displayed ferroelectric switching current behaviors with saturated polarisation loops. The experimental findings reported in this study highlight the potential of the cold-sintering process for chemical modification of lead zirconate titanate electroceramics.

Oxide-Halide Perovskite Composites for Simultaneous Recycling of Lead Zirconate Titanate Piezoceramics and Methylammonium Lead Iodide Solar Cells.

Global concerns over energy availability and the environment impose an urgent requirement for sustainable manufacturing, usage, and disposal of electronic components. Piezoelectric and photovoltaic components are being extensively used. They contain the hazardous element, Pb (e.g., in widely used and researched Pb(Zr,Ti)O3 and halide perovskites), but they are not being properly recycled or reused. This work demonstrates the fabrication of upside-down composite sensor materials using crushed ceramic particles recycled from broken piezoceramics, polycrystalline halide perovskite powder collected from waste dye-sensitized solar cells, and crystal particles of a Cd-based perovskite composition, C6H5N(CH3)3CdBr3 xCl3(1- x ). The piezoceramic and halide perovskite particles are used as filler and binder, respectively, to show a proof of concept for the chemical and microstructural compatibility between the oxide and halide perovskite compounds while being recycled simultaneously. Production of the recycled and reusable materials requires only a marginal energy budget while achieving a very high material densification of >92%, as well as a 40% higher piezoelectric voltage coefficient, i.e., better sensing capability, than the pristine piezoceramics. This work thus offers an energy- and environmentally friendly approach to the recycling of hazardous elements as well as giving a second life to waste piezoelectric and photovoltaic components.

Nonlinear magnetoelectric effect in a ring composite heterostructure

Objectives. The relevance of the study of magnetoelectric (ME) effect in ring ferromagnetic–piezoelectric heterostructures is due to the possibility of creating various ME devices having improved characteristics. A detailed investigation of the nonlinear ME effect in a ring composite heterostructure based on lead zirconate titanate (PZT) piezoceramics and Metglas® amorphous ferromagnetic (FM) alloy under circular magnetization is presented.Methods. The ME effect was measured by the low-frequency magnetic field modulation method. Excitation alternating- and constant magnetic bias fields were created using toroidal coils wound on a ring heterostructure for circular magnetization of the FM layer.Results. When excited with circular magnetic fields in a non-resonant mode, the ME ring heterostructure generates a nonlinear ME voltage of higher harmonics. The field and amplitude dependencies of the first three ME voltage harmonics were investigated. ME coefficients were obtained for the linear ME effect α(1) = 5.2 mV/(Oe·cm), the nonlinear ME effect α(2) = 6 mV/(Oe2·cm), and α(3) = 0.15 mV/(Oe3·cm) at an excitation magnetic field frequency f = 1 kHz. The maximum amplitudes of the 1st and 3rd harmonics were observed at a constant bias magnetic field H ~ 7 Oe, which is almost two times smaller than in planar PZT–Metglas® heterostructures.Conclusions. A nonlinear ME effect was observed and investigated in a ring heterostructure based on PZT piezoceramics and Metglas® amorphous FM alloy. Due to the absence of demagnetization during circular magnetization of the closed FM layer, nonlinear ME effects are detected at significantly lower amplitudes of the exciting alternating and constant bias magnetic fields as compared to planar heterostructures. The investigated ring heterostructures are of potential use in the creation of frequency multipliers.

Experimental investigation on interfacial defect detection for SCCS with conventional and novel contact NDT techniques

In order to ensure the mechanical performance and structural safety of steel–concrete composite structures (SCCS), advanced nondestructive testing (NDT) technique for bonding status at steel–concrete interfaces needs to be developed. In this study, the feasibility of multichannel analysis of surface waves (MASW)-based interfacial debonding detection is validated using the contact sensors array. Herein, the multichannel sensor arrays are composed of piezoceramic lead zirconate titanate patches and high-frequency acceleration meters, respectively. For comparison, the impact-response (IR) method and impact-transmission (IT) method are performed utilizing a force hammer and high-frequency acceleration meters, and corresponding damage imaging algorithms are developed. The applicability of ultrasonic computed tomography (CT) scanning test, scanning impact echo (IE) method, ultrasonic tomography (UT) technique on interfacial debonding detection is further discussed in depth. Research findings indicate that the developed contact MASW measurement can fully capture the variation of dispersion characteristics of surface waves induced by debonding defects in SCCS. The developed IR and IT methods are suitable for detecting interfacial debondings in different dimensions. Besides, the damage nephogram resolution of IR is higher than that of the IT method. In addition, the practicability of traditional ultrasonic CT scanning tests, scanning IE method, and UT techniques using commercial equipment is investigated. Experimental observations show that classical NDT testing techniques are incapable of effectively identifying the existence of interfacial damage and are unsuitable for NDT tests on SCCS. The research findings in this study clearly exhibit the precision and limitation of various contact NDT techniques and lay a solid foundation for interfacial debonding detection in practical SCCS.

Optimal Voltage Distribution on PZT Actuator Pairs for Vibration Damping in Beams with Different Boundary Conditions

In recent decades, many studies have been conducted on the use of smart materials in order to dampen and control vibrations. Lead zirconate titanate piezoceramics (PZT) are very attractive for such applications due to their ability of delivering high energy strain in the structure. A pair of piezoelectric actuators can actively dampen the resonances of the structure, but the damping effectiveness strongly relies on its location. Damping effectiveness can be substantially increased if the structure is fully covered with PZT actuator pairs and the voltage distribution on each pair is optimized. In this way, each actuator pair contributes to the vibration attenuation and only the driving voltage’s sign, distributed on each actuator pair, needs to be identified for each resonance. This approach is here applied to the case of Euler–Bernoulli beams with constant cross-section and the optimal voltage distribution is investigated for several boundary conditions. The theoretical model results were corroborated with finite element simulations, which were carried out considering beams covered by ten PZT actuator pairs. The numerical results agree remarkably well with the theoretical predictions for each examined case (i.e., free-free, pinned-pinned, and fixed-fixed).

Magnetoimpedance modulation in a planar magnetoelectric ferromagnet – piezoelectric heterostructure

The effect of a giant change in the impedance of ferromagnetic materials under the action of an external magnetic field is widely used to elaborate highly sensitive magnetic field sensors. The purpose of this work was to demonstrate the possibilities of controlling the magnitude of the magnetoimpedance in a ferromagnet-piezoelectric structure using an electric field. Method. In the measurements, we used a planar heterostructure containing a strip of amorphous ferromagnet Metglas, 25 µm thick and 25 mm long, mechanically connected to a bimorph, 0.5 mm thick and 30 mm long, made of piezoceramic lead zirconate titanate. An alternating current with a frequency of 30 kHz...10 MHz was passed through the strip, the structure was placed in a longitudinal permanent magnetic field of 0...500 Oe, an alternating electric field up to 400 V/cm with a frequency of 60 Hz...50 kHz was applied to the piezobimorph, and the change in the impedance of the strip was recorded. Results. In the absence of electric field, a narrowing of the magnetoimpedance magnetic fields region with a decrease in the current frequency and saturation of the magnetoimpedance in magnetic fields above 334 Oe were observed. The maximum value of the magnetoimpedance reached 18% at a current frequency of 1 MHz. The application of electric field to the piezobimorph led to the appearance of side components in the frequency spectrum of the voltage on the ferromagnetic layer, which indicates the amplitude-phase modulation of the magnetoimpedance. The amplitude modulation coefficient reached a maximum value of 6 · 10−3 for the electric field frequency of 11.2 kHz and decreased monotonically with an increase in the magnetic field. The modulation of the magnetoimpedance occurs due to the converse magnetoelectric effect in the heterostructure, which leads to the modulation of the magnetization of the ferromagnetic layer, and the subsequent change in the relative magnetic permeability and thickness of the skin layer in the ferromagnet. The results obtained can be used to create magnetic fields sensors controlled by an electric field.

Health monitoring of bacterial concrete structure under dynamic loading using electro-mechanical impedance technique: a numerical approach.

Health monitoring of structures using techniques based on the smart material is an innovative concept that is exploding technological revolutions in the field of civil engineering. The electro-mechanical impedance (EMI) technique is used for structural health monitoring (SHM) and to investigate the damages in the structures. The bacterial incorporation in concrete produces calcite material through metabolism process in presence of moisture and carbon dioxide, which improves the mechanical properties of concrete. Hence, its application in construction of the buildings will improve the health of structures. In this research paper, dynamic behaviour of the bacterial concrete was investigated numerically. The beams of size 700 × 150 × 150mm of bacterial concrete and control concrete were modelled using finite element-based package ANSYS19. The beam of bacterial concrete was simulated as per the characteristics of the materials produced after the bacterial metabolism reactions. The EMI technique was applied to investigate the health of these beams. Admittance (conductance and susceptance) signatures were determined using piezo-ceramic lead zirconate titanate (PZT) sensors installed at mid-point on the top surface of concrete beams. The beams were exposed to dynamic loading and the intensity of dynamic loading was increased in four sub-steps. For the quantification of strength development in the concrete beam, the root mean square deviation (RMSD) statistical index had been applied. It was observed that the bacterial concrete beam has more resistance to the dynamic loading.

Strength gain monitoring and construction quality evaluation on non-dispersible underwater concrete using PZT sensors

Owing to the undrained construction, not only the admixtures but also the hardening process is believed to have a significant effect on the final strength of non-dispersible underwater concrete (UWC). To ensure the stability and workability of UWC, this paper defined the hydration stages of UWC by conducting an early-age hydration monitoring experiment based on PZT (Piezoceramic Lead-Zirconate-Titanate) sensors and an isothermal calorimetry experiment. Additionally, a 90-day strength gain monitoring experiment and a compressive strength experiment were also carried out to establish a semi-empirical strength prediction model, which can be utilized to assess the real strength of UWC by substituting the monitoring data from practical structures. With practical application in a corroded bridge pier strengthened by prefabricated Basalt FRP (BFRP) shell and UWC, the strength prediction model presents a high accuracy on the prediction of hardening strength of UWC, and all the indices of the practical bridge pier strengthened by BFRP and UWC meet with the design codes. This indicates that the strength monitoring approach and construction quality evaluation method can apply to practical underwater structures.

Health monitoring of cracked concrete structure by impedance approach

Cracks/damages in concrete structures are the core concern for reduction of service life of infrastructures. Therefore, the effective technique is required for the prevention of cracks growth to improve the durability of structures. The cracks growth can be minimised by the incorporation of bacteria in the cementitious materials. The development of calcium carbonate heals the cracks automatically without any kind of human effort. The health of structures can be monitored and the presence of damages/cracks can be determined using various structural health monitoring techniques. In this paper, the research is focused on the monitoring of concrete cubes to explore the effect of bacteria. Two types of cube specimens were considered such as control concrete and bacterial concrete cubes, respectively. The six cubes of control concrete and six cubes of bacterial concrete of dimension 150 × 150 × 150 mm were cast. The compressive load of 300 kN was applied on control concrete cubes and bacterial concrete cubes to induce the incipient cracks/damages. After inducing the damages in the cubes, these cubes were tested after 7 days and 28 days curing. It was observed that the compressive strength of bacterial concrete was increased with respect to the control concrete by 19 % and 23 % at 7 and 28 days, respectively. The Electro-Mechanical Impedance (EMI) technique was used for monitoring the development of strength in both the cubes continuously. Piezo-ceramic lead Zirconate Titanate (PZT) patches were used to extract the signature. Admittance signatures were determined to access the health of cube specimens. Any deviation in signature from the healthy state that is baseline signature designates the change in compressive strength of concrete cubes. The increased strength was quantified in terms of signature change. The proposed investigation is applicable for monitoring of bacterial concrete structures. The research paper will be resulted new research directions and develop sustainable advancements in concrete technology.

Orientation-dependent, field-induced phase transitions in soft lead zirconate titanate piezoceramics

In situ high-energy X-ray diffraction (XRD) was performed on lead-zirconate-titanate-based ferroelectric materials with composition near the morphotropic phase boundary (MPB). The utilization of the two-dimensional area detector in in situ field-dependent experiments enables the complete analysis of the material response with respect to all azimuthal angles at each field amplitude. The studies reveal that the field-induced phase transition from tetragonal to rhombohedral is dependent on crystal orientation in Nb-doped PbZr0.53Ti0.47O3 that is in close compositional proximity to the MPB. However, only domain wall motion is activated in Nb-doped PbZr0.50Ti0.50O3, which is further in composition from the MPB. This synchrotron-based XRD characterization approach illustrates the importance in evaluating the orientation-dependence of phase transitions in piezoelectric and ferroelectric polycrystalline materials.

Interface debonding performance of precast segmental nano-materials based concrete (PSNBC) beams

The precast segmental concrete (PSC) structures and the nano-materials based concrete beams are widely applied to civil engineering. On the other hand, it is well known that nano-materials have physical effects and can significantly improve the concrete properties of cement-based materials. Therefore, the interface debonding performance of precast segmental nano-materials based concrete (PSNBC) beams is investigated in this study. Two concrete specimens with nano-materials and one concrete specimen without nano-materials were prepared and bonded into PSC beams with a high strength epoxy adhesive. The smart aggregates (SAs) made of piezoceramic Lead Zirconate Titanate (PZT) and concrete are used as the intelligent transducer of monitoring test specimen. The PSC beam was loaded periodically by screw jack to simulate the random debonding damage of different degrees. The experimental results show that the interface debonding performance of the concrete specimens with nano-materials is significantly enhanced and better than that of concrete specimens without nano-materials.

Optimum Operating Conditions for PZT Actuators for Vibrotactile Wearables

Recently, vibrotactile wearables have received much attention in fields such as medicine, psychology, athletics and video gaming. The electrical components presently used to generate vibration are rigid; hence, the design and creation of ergonomical wearables are limited. Significant advances in piezoelectric components have led to the production of flexible actuators such as piezoceramic lead zirconate titanate (PZT) film. To verify the functionality of PZT actuators for use in vibrotactile wearables, the factors influencing the electromechanical conversion were analysed and tested. This was achieved through theoretical and experimental analyses of a monomorph clamped-free structure for the PZT actuator. The research performed for this article is a three-step process. First, a theoretical analysis presents the equations governing the actuator. In addition, the eigenfrequency of the film was analysed preceding the experimental section. For this stage, by applying an electric voltage and varying the stimulating electrical characteristics (i.e., voltage, electrical waveform and frequency), the optimum operating conditions for a PZT film were determined. The tip displacement was measured referring to the mechanical energy converted from electrical energy. From the results obtained, an equation for the mechanical behaviour of PZT films as actuators was deduced. It was observed that the square waveform generated larger tip displacements. In conjunction with large voltage inputs at the predetermined eigenfrequency, the optimum operating conditions for the actuator were achieved. To conclude, PZT films can be adapted to assist designers in creating comfortable vibrotactile wearables.

Wave propagation simulation and its wavelet package analysis for debonding detection of circular CFST members

In order to investigate the interface debonding defects detection mechanism between steel tube and concrete core of concrete-filled steel tubes (CFSTs), multi-physical fields coupling finite element models constituted of a surface mounted Piezoceramic Lead Zirconate Titanate (PZT) actuator, an embedded PZT sensor and a circular cross section of CFST column are established. The stress wave initiation and propagation induced by the PZT actuator under sinusoidal and sweep frequency excitations are simulated with a two dimensional (2D) plain strain analysis and the difference of stress wave fields close to the interface debonding defect and within the cross section of the CFST members without and with debonding defects are compared in time domain. The linearity and stability of the embedded PZT response under sinusoidal signals with different frequencies and amplitudes are validated. The relationship between the amplitudes of stress wave and the measurement distances in a healthy CFST cross section is also studied. Meanwhile, the responses of PZT sensor under both sinusoidal and sweep frequency excitations are compared and the influence of debonding defect depth and length on the output voltage is also illustrated. The results show the output voltage signal amplitude and head wave arriving time are affected significantly by debonding defects. Moreover, the measurement of PZT sensor is sensitive to the initiation of interface debonding defects. Furthermore, wavelet packet analysis on the voltage signal under sweep frequency excitations is carried out and a normalized wavelet packet energy index (NWPEI) is defined to identify the interfacial debonding. The value of NWPEI attenuates with the increase in the dimension of debonding defects. The results help understand the debonding defects detection mechanism for circular CFST members with PZT technique.

Interplay of strain mechanisms in morphotropic piezoceramics

A large number of transducers, ultrasonic motors or actuators are based on lead zirconate titanate (PZT) piezoceramics, with compositions near the morphotropic phase boundary (MPB) where the relevant material properties approach their maximum. Since the best piezoelectric properties, in particular the highest recoverable strains, are observed for these MPB compositions with phase coexistences, a separate analysis of each phase is mandatory. Here we present a sophisticated method to correlate the macroscopic strain observations to mechanisms on the atomic scale. The technique allows a quantification of all contributing strain mechanisms such as lattice strain, domain switching and phase transition for each phase. These results indicate that the major strain contribution is of structural instead of microstructural origin and the electric field induced phase transition occurs through polarisation rotation. Such a mechanism could be generalised in other MPB piezoceramics and will be useful to design and optimise the next generation of high performance piezoelectric materials.

Design of a d 33-mode piezocomposite electricity generating element and its application to bridge monitoring

The piezoelectric effect is used in sensing applications such as in force and displacement sensors. However, the brittleness and low performance of piezoceramic lead zirconate titanate (PZT) often impede its applicability in civil structures which are subjected to large loads. The concept of a piezocomposite electricity generating element (PCGE) has been proposed for improving the electricity generation performance and overcoming the brittleness of piezoceramic wafers. The post-curing residual stress in the PZT layer constitutes a main reason for the PCGE’s enhanced performance, and the outer epoxy-based composites protect the brittle PZT layer. A d33-mode PCGE designed for bridge monitoring application was inserted in a bridge bearing to provide a permanent and simple weigh-in-motion system. The designed PCGEs were tested through a series of tests including fatigue and dynamic tests to verify their applicability for monitoring purposes in a bridge structure. A simple beam example was presented to show the applicability of the proposed bridge bearing equipped with the PCGE for adequately measuring the traffic loads.

An Experimental Assessment of PZT Patches for Impedance-Based SHM Applications

Abstract In this paper, we present an alternative method for assessing the sensitivity of lead zirconate titanate (PZT) piezoceramics for damage detection in structural health monitoring (SHM) systems based on the electromechanical impedance (EMI) principle. An assessment of the sensitivity is obtained experimentally using the pencil lead break (PLB) method, which is frequently used in acoustic emission (AE) systems. Tests were carried out on an aluminum beam, and the results show a clear relationship between the damage indices obtained from the electrical impedance signatures of the PZT patch bonded to the monitored structure and the power spectral density (PSD) obtained using the PLB method.

Production and Properties of Nanostructured Metal-Oxide Lead Zirconate–Titanate Piezoceramics

Compact ceramic samples of lead zirconate–titanate are sintered from nanocrystalline (d av = = 25 nm) Pb(Zr0.52Ti0.48)O3 powder synthesized by thermal decomposition of an oxalate precursor. Conditions of nanopowder compaction have been found and kinetics of sintering and growth of nanocrystallites and coarser grains formed during consolidation have been studied. The lead zirconate–titanate ceramic samples consolidated from nanopowders are sintered at lower (by 300–350°C) temperatures and have higher (by 25–45%) dielectric and piezoelectric properties as compared to samples fabricated by conventional solid-state technology. Two-level grain structure is formed during sintering: nanocrystallites divided by low-angle boundaries and descending from initial nanocrystalline particles and consolidated coarser micrograins divided by high-angle boundaries. Sintering of the lead zirconate–titanate ceramics from nanocrystalline powders permits controlling the nanoscale size of crystallites and thus the nanostructured features of consolidated material.

Electromechanical modelling for piezoelectric flextensional actuators

The piezoelectric flextensional actuator investigated in this paper comprises three pre-stressed piezoceramic lead zirconate titanate (PZT) stacks and an external, flexure-hinged, mechanical amplifier configuration. An electromechanical model is used to relate the electrical and mechanical domains, comprising the PZT stacks and the flexure mechanism, with the dynamic characteristics of the latter represented by a multiple degree-of-freedom dynamic model. The Maxwell resistive capacitive model is used to describe the nonlinear relationship between charge and voltage within the PZT stacks. The actuator model parameters and the electromechanical couplings of the PZT stacks, which describe the energy transfer between the electrical and mechanical domains, are experimentally identified without disassembling the embedded piezoceramic stacks. To verify the electromechanical model, displacement and frequency experiments are performed. There was good agreement between modelled and experimental results, with less than 1.5% displacement error. This work outlines a general process by which other pre-stressed piezoelectric flextensional actuators can be characterized, modelled and identified in a non-destructive way.

Evidence of temperature dependent domain wall dynamics in hard lead zirconate titanate piezoceramics

This work presents a study of the domain wall dynamics in Pb(Zr1−xTix)O3 (PZT)-based piezoceramics by means of the temperature dependence non-linear dielectric response and hysteresis loop measurements. In soft PZT, non-linear response gradually increases as the temperature is raised. A similar response is displayed by hard PZT at low temperatures. However, rather more complex behavior is detected at temperatures above 200 K. The anomalous response, which is very marked at room temperature, becomes even greater when the electric field is increased. The non-linear dielectric response is analyzed in the framework of the Rayleigh model. The results suggest a clear change in the domain wall dynamics in hard PZT, which is not observed in soft PZT. Observation of the hysteresis loops confirms that a strong effect of domain wall pinning emerges near room temperature. The change in domain wall dynamics appears as the main cause of the dielectric response difference between both kinds of materials at room temperature.

Charge accumulation in grain boundary promotes intergranular fracture of lead zirconate titanate piezoceramics under mechanical and electric load

This paper presents the surface potential distributions of pores, grain boundaries (GBs) and indentation cracks of lead zirconate titanate piezoceramics. The pores, GBs and indentation cracks in poled samples are higher potential regions in comparison to other regions. However, GBs and indentation cracks have no distinguishing potential feature in unpoled samples. Coupled with an investigation of the fracture modes, the role of the electrostatic repulsive force induced by charges accumulated in GBs on the ferroelectric fracture is discussed.