PZT Content Research Articles

Constitutive model of piezoelectric/shape memory polymer composite

The PZT/SMP composite material, combining piezoelectricity and shape memory effects, has emerged as a novel multifunctional smart material and has gained significant attention. The establishment of an effective constitutive model, describing the mechanical properties of the composites, holds tremendous importance in both theoretical and engineering realms. This study aims to develop a model to investigate the mechanical properties of PZT/SMP composites. By incorporating the deformation mechanisms of the PZT/SMP composites and the theories of viscoelasticity, the constitutive equation for PZT/SMP composites has been established. Based on composite material theory and the properties of transversely isotropic materials, combined with the material parameter equations for SMP, the material parameter equations of PZT/SMP composites have been established. Using the polarization direction of the composite material as an example, we conduct simulation analyses on PZT/SMP composites with various volume fractions of PZT particles by using the developed constitutive model. The variations in material parameter performance, piezoelectric performance, and shape memory performance are investigated. The simulation results demonstrate that an increase of PZT content in the PZT/SMP composite enhances both the piezoelectric and mechanical properties of the composite material, which significantly influences the shape memory process.

Optimization of polarization direction on 3D printed 3-3 piezoelectric composites for sensing application

As a typical smart material, 3-3 piezoelectric composite has a wide application in the fields of ultrasonic transducer, underwater acoustic detection and so on. Direct ink writing has great advantages in preparing 3-3 composites because of its straight-forward process and accurate control of the composites structure. In this work, a water-based PZT slurry of 52.0 vol% solid content was prepared with high storage and loss modulus and shear thinning characteristics. PZT ceramic scaffolds with different porosity were realized by direct ink writing, and 3-3 piezoelectric composites were then prepared by compounding PZT scaffold with epoxy resin. Compared with the common Z-polarized samples, the Y-polarized samples show higher piezoelectric coefficients d 33 and piezoelectric voltage coefficient g 33 . When PZT content of the 3-3 composite was 34.4 vol%, the Y-polarized sample showed the highest g 33 of 81.65 mV m/ N, and the sensing sensitivity could reach 9.81 V/N. Structural configuration and design via direct writing process show great potential for tuning and optimizing the piezoelectric properties of piezocomposites.

Design and durability of PZT/PVDF composites based on pavement perception

Highway pavement perception devices made from conventional piezoelectric materials are unsuitable for use in a complex road traffic environment because they lack durability. In this study, the design and durability performance of piezoelectric materials based on pavement perception were assessed. First, lead zirconate titanate (PZT)/polyvinylidene fluoride (PVDF) composites with various volume ratios were prepared with PZT and PVDF as raw materials. Then, their piezoelectric and dielectric properties were tested, and the change mechanism of electrical properties of the materials was analysed by examining their crystal structures. Their compressive and flexural strengths were tested, and the change mechanism of mechanical properties was analysed with the use of a scanning electron microscope. The optimal volume ratio of the PZT/PVDF composite was determined by combining test results with the stress characteristics of a pavement structure. Finally, PZT/PVDF composites with the best volume ratio were used to prepare piezoelectric perception devices. The devices were placed in an asphalt mixture, and the output of their perception signals was tested by simulating vehicle loads. The results show that with an increase in PZT content, the dielectric property of the composite piezoelectric material first increased and then decreased, the piezoelectric property gradually increased, and the compressive and flexural strengths both gradually decreased. The comprehensive properties of PZT/PVDF composites with a PZT volume ratio of 50% were superior; after 150,000 repeated loads, the perception signal output was stable, and the sensor had good durability.

Can nano PZT-OPC composites be used as a smart γ-ray attenuator?

Nano PbZr0.52Ti0.48O3-ordinary Portland cement (PZT-OPC) composites were fabricated by a ball milling technique with different PZT content (30, 50, 70, and 90% by weight). The prepared samples were annealed at 600 °C. The structure, morphology, thermal and electrical properties of these annealed samples were investigated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). The effects of PZT on dielectric and piezoelectric properties of the composites were investigated. γ-ray spectroscopy was used to measure the γ-ray attenuation coefficients of the annealed nanocomposite samples using the 661.7 keV γ-ray of 137Cs source. The microstructure changes of the prepared composite samples were investigated using the positron annihilation lifetime (PAL) and Doppler broadening (DB) techniques. The XRD patterns show both PZT and cement peaks. Also, these patterns indicate the presence of PZT retards the hydration process of the Portland cement. The FTIR spectra show the major absorption bands for both PZT and cement. SEM images show the binding between calcium silicate hydrate and PZT which may be a better factor for improving the mechanical properties of the cement. TGA curves show a higher thermal weight loss for 50% PZT-OPC composite sample. The PZT-OPC composite sample with 50% PZT content shows the highest γ-ray mass attenuation coefficient compared with the other composite samples. The positron annihilation spectroscopy (PAS) results show that the size of large voids and the concentration of small defects increase by increasing PZT content. Also, these results reveal that the core electrons slightly reduced by increasing PZT content. The results indicate that the dielectric constant and piezoelectric coefficient values slightly and rapidly increase for composite samples with PZT content <50% and >50%, respectively. Finally, the 50% PZT-OPC composite sample showed novel shielding and acceptable piezoelectric properties to be used as a smart shield.

Piezoelectric properties and damping behavior of highly loaded PZT/polyurethane particulate composites

In this study, using a solution casting process, thermoplastic polyurethane elastomer (TPU) composites containing different contents of lead zirconate titanate (PZT) ferroelectric particles were produced. The damping treatment of composites at high volume of fillers was investigated. SEM micrographs showed that PZT particles had a proper distribution in the PU matrix. Differential scanning calorimetry (DSC) thermograms indicates that melting enthalpy decreases by raising PZT filler content. The results of the dynamic mechanical thermal analysis (DMTA) proved that the magnitude of loss factor (tan δ) strongly depends on PZT content, and it decreased from 0.51 to 0.27 as PZT content increased. The value of E0 increases to 0.32 GPa in the composite reinforced with 50 v% of PZT. The role of PZT on the acoustic behavior of TPU was measured using the acoustic absorption coefficient (a). The results showed that as PZT content increased from 0 to 50%, the acoustic absorption coefficient reached 0.25 at 6000 Hz frequency. The composites of PZT/PU with 0–3 connectivity were poled, and the optimal poling conditions that could be applied without sample breakdown were studied. Moreover, we prepared composites containing 70 vol% PZT particles by modifying the particles. Modification of PZT particles caused a decrease in both d33 and g33 constants of the PZT/PU composites.

Multiferroic triphase BFO-PZT-PVDF composite with significant magnetoelectric response for multistate device applications

Triphase multiferroic composites with higher degree of freedom, provide a new platform for developing novel and smart technological applications. In this context, here we present a new triphase composite, consisting of bismuth ferrite (BFO) and lead zirconate titanate (PZT) synthesized using sol‒gel auto-combustion and solid-state routes, respectively and then subsequently dispersed into a PVDF polymatrix, leading to a triphase composite (BFO-PZT-PVDF). Structural analysis confirmed the composite formation as all the intensity peaks were either matched with BFO or PZT phases. Morphological analysis revealed that pure BFO and PZT formed well defined grains with sharp grain boundaries. However, when they are dispersed in the polymer matrix, their boundaries became diffused. Worth mentioning ferroelectric parameters like saturation polarization, remanent and recoverable energy density are measured from bipolar polarization loops. It is noticed that maximum polarization is decreased while coercivity is increased with the increment of PZT contents in the composite. Vibrating sample magnetometer confirmed the variation in magnetic features, exactly in accordance as required for significant magnetoelectric coupling for practical utilization. The extent of magnetoelectric coupling supports the potential applications of these triphase composites for energy storage and multistate devices.

Preparation and Properties of Epoxy Piezoelectric Vibration Reduction Composites

The epoxy resin (E-51) was used as polymer matrix, conductive carbon black (CB) as conductive filler, and PZT was used to prepare a composite by curing. The effects of PZT and CB content on the properties of PZT/ CB/ EP piezoelectric composite were studied. When the PZT content reaches 40 wt%, the optimized vibration attenuation properties of PZT/CB/EP materials could be achieved with a loss factor of 0.9 from room temperature to 60 °C. With the increase of PZT content, the bending strength of PZT/CB/EP piezoelectric composite vibration reduction material firstly increased from 45 MPa to 65 MPa and then decreased to 38 MPa. At room temperature, the dielectric constant increased from 7 to 50, and the dielectric loss increased from 0.1 to 0.5.

Electromagnetic radiation detection in cement-mortar/lead zirconate titanate composites using drop-weight impact technique

Investigation on the electromagnetic radiation (EMR) emission from cement-mortar/lead zirconate titanate (cement-mortar/PZT) composites using a drop-weight impact technique has been undertaken to explore its possible applications in civil structures as a sensor. Unpoled soft grade PZT (SP-5A) powder, having a particle size of 1 µm is used for preparing the cement-mortar/PZT composite samples onto which the experiments were conducted in unpoled state. The EMR generation from cement-mortar/PZT composites is due to the accelerated movement of the charged particles in the pores of hydrated cement and due to oscillations of dipoles in the PZT. The values of EMR voltage, the average release rate of EMR energy, and dominant frequency are observed to increase with the rise of the PZT content and the height of impact. The deformation/strain in the composite could be sensed by measuring the EMR voltage. Also, the addition of PZT in mortar results in an increase in the compressive strength and bulk density and a decrease in the porosity of the composite. The effect of the separation of the antenna and the composite samples on the EMR voltage has also been studied. The results obtained, foreshadow the prospect of the present non-destructive technique, a better option for structural health monitoring.

Structure, dielectric, piezoelectric, antiferroelectric and magnetic properties of CoFe2O4–PbZr0.52Ti0.48O3 composite ceramics

Magnetoelectric composite ceramics CoFe2O4–Pb(Zr0.52Ti0.48)O3(CFO-PZT) with different molar ratios (CFO/PZT = 1:4, 1:5, 1:6 and 1:7) were prepared by combining chemical coprecipitation and sol-gel method. The effects of molar ratio on the structure, dielectric and multiferroic properties were investigated. XRD results indicate that the composites show bi-phase structure, which can be indexed as CFO and PZT. SEM and EDS images present that the grain distribution is nonuniform, the average grain size of both CFO and PZT are near 1 μm, while they increase slightly with increasing the molar ratio. The dielectric constant is larger than 2000 in low frequency (<1 kHz) while it decreases to near 500 when the frequency is larger than 4 kHz. The dielectric loss of the sample (1:6) is the maximal, while the sample (1:5) shows the smallest one. The Curie temperature of PZT in the composites is is near 350 °C, which is larger than that of pure PZT sample (~330 °C), indicating the tuning effect of composition on the transition temperature. The samples present a very broad relaxation and higher disorder level, displaying dispersion behavior. The composites show antiferroelectric behavior in high frequency range while it can recover to normal ferroelectric property at low frequency. The antiferroelectric phenomenon gradually disappears after training effect. The composites with molar ratios of 1:4 and 1:6 exhibit better ferroelectricity and lower conductivity, the values of residual polarization (Pr) are 29.11 and 30.03 μC/cm2, respectively. The electrostrictive strain is 0.086% at 40 kV/cm when the molar ratio is 1:5, the sample (1:7) shows the smallest value (0.044%). All the samples show ferromagnetic properties, the magnetization decreases with increasing the PZT content. The saturation magnetization (Ms) and residual magnetization (Mr) of the samples decrease as the PZT content in the composite increases. Among them, the composite with the molar ratio of 1:4 shows better magnetic properties, the value of Mr and coercive field are respectively 1.67 emu/g and 404.26 Oe.

Facile Fabrication of a Novel PZT@PPy Aerogel/Epoxy Resin Composite with Improved Damping Property.

A novel lead zirconate titanate@polypyrrole (PZT@PPy) aerogel (PPA) was fabricated via in-situ polymerization and subsequent freeze-drying method. The porous PPA was then saturated with epoxy resin to obtain the PPA/epoxy composite (PPAE) by a simple vacuum filling method. In this way, the filler content and dispersion uniformity are well guaranteed, which is in favor of improving the damping and mechanical properties of composites. The morphology and structure of PPAs were investigated using XRD, SEM, EDS and nitrogen absorption and desorption measurements. The results showed that the PPA possessed a three-dimensional porous structure with uniform lead zirconate titanate (PZT) distribution. The influence of PZT content on the damping property of PPAE composite was investigated by dynamic mechanical analysis (DMA). PPAE-75 (i.e., the mass ratio of PZT to PPy is 75 wt %) exhibited the maximum damping loss factor value, 360% higher than that of the epoxy matrix, suggesting good structural damping performance.

Fabrication and performance of a self-powered damage-detection aggregate for asphalt pavement

The use of wireless sensors to monitor concealed damage to asphalt pavement has become an important research topic. The main obstacle to wireless sensor applications is the protection of sustainable power supplies. For this study, the self-powered damage-detection aggregate (SPA) was fabricated by encapsulating the piezoelectric vibrator with epoxy resin, prepared by compositing the piezoelectric ceramics (PZT) and polyvinylidene fluoride. The optimal PZT content in the piezoelectric vibrator was recommended as 60% according to the test results. The sensing and driving characteristics, sensitivity, and mechanical strength of the SPAs were studied, and the best SPA is recommended. The compressive strength of the SPA was 16 MPa at a temperature of 160 °C, which is far greater than the average tire pressure of 0.5 MPa to 1.3 MPa on pavement. During laboratory testing, a voltage of 75.0 V and an energy of 4.31 μJ was harvested when an SPA was embedded in an asphalt mixture slab. The coefficient of the acoustic wave attenuation, obtained from the SPA, decreased as the crack width in an asphalt pavement increased. We proved that the application of acoustic waves excited by the SPA to monitor concealed cracks of asphalt pavement is feasible.

Highly-Loaded Thermoplastic Polyurethane/Lead Zirconate Titanate Composite Foams with Low Permittivity Fabricated using Expandable Microspheres.

The sensitivity enhancement of piezocomposites can realize new applications. Introducing a cellular structure into these materials decreases the permittivity and thus increases their sensitivity. However, foaming of piezocomposites is challenging because of the high piezoceramic loading required. In this work, heat-expandable microspheres were used to fabricate thermoplastic polyurethane (TPU)/lead zirconate titanate (PZT) composite foams with a wide range of PZT content (0 vol % to 40 vol %) and expansion ratio (1–4). The microstructure, thermal behavior, and dielectric properties of the foams were investigated. Composite foams exhibited a fine dispersion of PZT particles in the solid phase and a uniform cellular structure with cell sizes of 50–100 μm; cell size decreased with an increase in the PZT content. The total crystallinity of the composites was also decreased as the foaming degree increased. The results showed that the relative permittivity (εr) can be effectively decreased by an increase in the expansion ratio. A maximum of 7.7 times decrease in εr was obtained. An extended Yamada model to a three-phase system was also established and compared against the experimental results with a relatively good agreement. This work demonstrates a method to foam highly loaded piezocomposites with a potential to enhance the voltage sensitivity.

Electromagnetic radiation detection in 0-3 cement-PZT composite under impact loading

Electromagnetic responses of cement–PZT composites under impact loading have been presented in this work. The values of density, dielectric constant and EMR voltage increase while that of porosity and loss tangent decrease with increase in PZT content. Filler (PZT) concentration dependent dielectric constant as well as loss tangent data shows exponential variation. The emitted EMR voltage as well as average EMR energy release rate for 21 cm height of impact increase from 1.03 V to 2.24 V and 0.10092 V2-sec/sec to 0.4635 V2-sec/sec respectively with the increasing PZT content (5% to 40%). The EMR responses of the composites were also found to be proportional to the height of impact in all the composites tested, indicating that the measurement of EMR responses from the cement based composites may be useful for deformation monitoring.

Fabrication and characterization of a novel carbonated 0-3 piezoelectric γ-C2S composite

0-3 cement-based piezoelectric composites have been proposed as sensors and actuators in civil engineering for structural heath monitoring. Previous studies are focused exclusively on hydraulic binders such as ordinary Portland cement and sulfoaluminate cement. In this paper, a novel 0–3 piezoelectric composite is presented which consists of non-hydraulic gamma dicalcium silicate (γ-C2S) as the matrix and lead zirconate titanate (PZT) as the piezoelectric phase, utilizing carbonation reaction for the attainment of high mechanical strength. The effect of PZT content on the piezoelectric, dielectric and mechanical properties is investigated. When exposed to a CO2-rich environment for 2 h, the composite with 60 vol% PZT develops rapid strength to be 38.5 MPa and possesses a piezoelectric coefficient (d33) of 24.6 pC/N, a dielectric constant of 67.5 and tanδ of 0.11, which are comparable to what has been reported in other studies.

Reduced leakage current and improved multiferroic properties of 0.5((1−x)BLPFO-xPZT)-0.5PVDF composite films

0.5((1−x)Bi0.8La0.1Pr0.2FeO3 (BLPFO)-xPb(Zr0.52Ti0.48)O3 (PZT))-0.5Polyvinylidene difluoride (PVDF) composite films with x variations 0.25, 0.40 and 0.50 were synthesized using two step mixing, followed by hot pressing. The structural, microstructural, dielectric, magnetic, ferroelectric and magnetodielectric properties of composite films have been systematically investigated. The measurement of the dielectric properties at 1kHz shows that the dielectric loss (tanδ) decreases with increasing the volume fraction of PZT. The value of maximum room temperature εr ~78 and low tanδ ~0.061 for 0.5((1−x)BLPFO-xPZT)-0.5PVDF composite film with x=0.50 suggests its usefulness for capacitor applications. For predictions of effective dielectric constant of composite films experimental data were fitted with Lichtenecker model. Among all the composite films, the film with x=0.50 was found to exhibit smallest leakage current density ~7×10−8A/cm2 and hence improved electrical resistivity. The variation of magnetization with temperature indicates the presence of spin glass behavior along with the ferromagnetic component at 5K. The value of remnant polarization (2Pr) is found to increase with increase of PZT content in composite films. In the present composite films a significant dependence of dielectric constant on magnetic field has been observed, and highest value of magnetodielectric response of 2.85% is observed for composite film with x=0.50.

Piezoelectric and dielectric behavior of 0-3 asphalt-based composites with carbon black

Asphalt-based piezoelectric composites have great potential to serve as sensors to monitor the health of asphalt pavements due to their compatibility with asphalt pavements and appropriate response behaviors. This paper reports the preparation of asphalt-based piezoelectric composites doped with carbon black to investigate the influence of lead zirconate titanate (PZT) and carbon black contents on the dielectric, piezoelectric, and electromechanical properties of the composites. The addition of carbon black as a conductive phase facilitates the poling process, which improves the poling efficiency. The results indicate that with increasing PZT content, the dielectric constant (εr), piezoelectric strain factor (d33) and planar electromechanical coupling coefficient (Kp) of the composites increase. εr, d33, and Kp of the composites increase with the increase of carbon black content, and the composites with 0.3vol% carbon black present the maximum values of 154.89, 75.74 pC/N and 37.73%, respectively, then decrease with greater carbon black content. However, tanδ shows an opposite trend with the variation of PZT and carbon black contents. With 80vol% PZT and 0.3vol% carbon black, tanδ decreases to the minimum value of 20.80, then increases with further increases in carbon black content. The variation of the mechanical quality factor (Qm) shows little association with the contents of PZT or carbon black.

Structure and phase formation behavior and dielectric and magnetic properties of lead iron tantalate-lead zirconate titanate multiferroic ceramics

Multiferroic (1−x)Pb(Fe0.5Ta0.5)O3–xPb(Zr0.53Ti0.47)O3 (or PFT–PZT) ceramics were synthesized by solid-state reaction method. The crystal structure and phase formation of the ceramics were examined by X-ray diffraction (XRD). The local structure surrounding Fe and Ti absorbing atoms was investigated by synchrotron X-ray Absorption Near-Edge Structure (XANES) measurement. Dielectric properties were studied as a function of frequency and temperature using a LCR meter. A vibrating sample magnetometer (VSM) was used to determine the magnetic hysteresis loops. XRD study indicated that the crystal structure of the sample changed from pure cubic to mixed cubic and tetragonal with increasing PZT content. XANES measurements showed that the local structure surrounding Fe and Ti ions was similar. Dielectric study showed that the samples underwent a typical relaxor ferroelectric behavior while the magnetic properties showed very interesting behavior with square saturated magnetic hysteresis loops.

Structural, Dielectric, and Electrical Properties of Bi1−x Pb x Fe1−x (Zr0.5Ti0.5) x O3

Polycrystalline samples of Bi1−x Pb x Fe1−x (Zr0.5Ti0.5) x O3 (BPFZTO) with x = 0.0, 0.2, 0.3, and 0.4 were prepared by high-temperature solid-state reaction. Preliminary structural analysis of calcined powders of the materials by use of x-ray powder diffraction confirmed formation of single-phase systems with the tetragonal structure. Room-temperature scanning electron micrographs of the samples revealed uniform distribution of grains of low porosity and different dimensions on the surface of the samples. The frequency–temperature dependence of dielectric and electric properties was studied by use of dielectric and complex impedance spectroscopy over a wide range of frequency (1 kHz to 1 MHz) at different temperatures (25–500°C). The dielectric constant of BiFeO3 (BFO) was enhanced by substitution with Pb(Zr0.5Ti0.5)O3 (PZT) whereas the dielectric loss of the BPFZTO compounds decreased with increasing PZT content. A significant contribution of both grains and grain boundaries to the electrical response of the materials was observed. The frequency-dependence of the ac conductivity of BPFZTO followed Jonscher’s power law. Negative temperature coefficient of resistance behavior was observed for all the BPFZTO samples. Conductivity by thermally excited charge carriers and oxygen vacancies in the materials was believed to be of the Arrhenius-type.

MPB Phase Transition and Microstructure of (1 – x)PMN–xPZT Activated by 0.05BZN Ceramics

The relaxor ferroelectric materials can be found in morphotropic phase boundary (MPB) existing between tetragonal and cubic phase. Since the MPB shifts to other phases by adding ceramics composition. [(1 – x)Pb(Mg1/3 Nb2/3)O3–x Pb(Zr0.52Ti0.48)O3] were doped by 0.05Ba(Zn1/3 Nb2/3)O3 when x = 0.4, 0.3, and 0.2 ceramics, which prepared by using a two–step sintering process. The MPB transitions were studied by the use of XRD. The samples, at x = 0.4, were in MPB and then gradually shifted to cubic phase at x = 0.2. The microstructure of samples fracture found that the largest grain size of 4.51 μm for x = 0.2. This study using TEM technique which demonstrated a crystalline morphology with the largest crystal size about 1.293 μm at x = 0.3. These results also revealed that not only the ferroelectric phase shifted to relaxor behavior with decreasing PZT contents in PMN–PZT system but also activated by BZN, which led to the presence of the relaxor behavior.

Elaboration and dielectric property of modified PZT/epoxy nanocomposites

Composites of lead zirconate titanate (PZT) 50 nm nanoparticles and epoxy resins have been produced with various PZT contents from 0 to 20 wt%. The morphology and thermal properties of prepared composites were characterized using scanning electron microscopy and differential scanning calorimetry. The PZT nanoparticles were found to be well dispersed in the epoxy resin matrix. The glass transition temperature (Tg) value of the nanocomposites increases from 164 to 178°C with increasing the PZT weight fraction. The dielectric composites properties dependences were studied via a wide range of frequency from 10 Hz to 100 kHz. The dielectric constant of PZT/epoxy composite was increased from 5.56 to 6.29 (at f = 1 kHz, T = 30°C), respectively to the incorporated PZT amount, and these values are higher than that the dielectric constant of pure cured epoxy resin, ε = 4.86. POLYM. COMPOS., 37:455–461, 2016. © 2014 Society of Plastics Engineers