Papers by Keyword: PZT

Abstract: Electromechanical impedance (EMI) sensing with bonded piezoelectric patches is a compact option for structural health monitoring at high frequencies. This study evaluates the detectability of submillimeter microcracks in an Inconel 718 plate using a surface-bonded lead zirconate titanate (PZT) transducer through a finite element-based harmonic analysis. A two-dimensional coupled-field model represents a 20 × 20 × 5 mm³ plate and a PIC255 patch with an in-plane size of 10 × 10 × 0.5 mm³. The model performs a 10–100 kHz voltage sweep at 0.5 V to compute electrical resistance. Damage is introduced as circular notch-like defects with diameters of 0.25, 0.50, and 0.75 mm at nine locations that vary the sensor-to-defect distance. A mesh convergence study ensures numerical stability. Damage sensitivity is quantified using Root Mean Square Deviation (RMSD) of impedance signatures relative to the healthy baseline. Results show that frequency bands around local resonances provide the strongest separation between healthy and damaged states, with the most discriminative band observed near 54–57 kHz. RMSD increases monotonically with defect diameter and decreases with distance from the sensor, demonstrating an anisotropic positional sensitivity that is stronger along the patch axis.

Abstract: Accurate determination of piezoelectric properties such as piezoelectric charge coefficients (d₃₃) is an essential step in the design process of sensors and actuators using piezoelectric effect. In this study, a cost-effective and accurate method based on dynamic loading technique was proposed to determine the piezoelectric charge coefficient d₃₃. Finite element analysis (FEA) model was developed in order to estimate d₃₃ and validate the obtained values with experimental results. The experiment was conducted on a piezoelectric disc with a known d₃₃ value. The effect of measuring boundary conditions, substrate material properties and specimen geometry on measured d₃₃ value were conducted. The experimental results reveal that the determined d₃₃ coefficient by this technique is accurate as it falls within the manufactures tolerance specifications of PZT-5A piezoelectric film d₃₃. Further, obtained simulation results on fibre reinforced and particle reinforced piezoelectric composite were found to be similar to those that have been obtained using more advanced techniques. FE-results showed that the measured d₃₃ coefficients depend on measuring boundary condition, piezoelectric film thickness, and substrate material properties. This method was proved to be suitable for determination of d₃₃ coefficient effectively for piezoelectric samples of any arbitrary geometry without compromising on the accuracy of measured d₃₃.

Abstract: In this paper, we consider the technological features of the formation of thin ferroelectric films of lead zirconate titanate (PZT) by the method of plasma high-frequency reactive sputtering. The crystal structure, morphology and elemental composition of films deposited on silicon and oxidized silicon substrates are investigated. It is shown that the obtained PZT films have a perovskite structure and are polycrystalline with a predominant crystallite growth in the (110) direction. An automated test bench has been designed and manufactured for measuring the electrophysical parameters of ferroelectric films. The measured CV characteristics of the Ni/PZT/Si structure show the hysteresis caused by the polarization of the PZT film. It is noted that the asymmetry of the dependence of the spontaneous polarization on the applied voltage can be caused by the presence of surface states at the PZT/Si interface.

Abstract: Structural health monitoring (SHM) and damage detection techniques have recently gained attention in various fields of engineering for preventing catastrophic failures. Among different SHM techniques, Lamb wave propagation methods are widely used as these waves can propagate large distance from a single source. Piezoelectric (PZT) transducers are used here as actuators and sensors to generate and receive wave signals. Most of the studies conducted on wave propagation in plates are by use of conventional d₃₁ mode piezoelectric transducer. However, so far very few studies have been done using other types of PZT transducers. The primary objective of this paper is to determine and study the wave responses in a thin plate using different types of PZT transducers. The results indicate that the d₃₁ and d₃₃ type transducers generate Lamb waves, whereas d₂₄ and d₁₅ type transducers generate shear horizontal waves in two orthogonal directions. The study indicates that each of the transducers has its own directional property. The present study will be helpful for the application of Lamb waves and shear horizontal waves in plate structures

Abstract: Lead zirconate titanate (PZT) is a wide versatile material applied in several electronic devices. Some of dielectric and piezoelectric characteristics depend on phase formation, crystallization and composition. In this work, we prepare PZT powder samples with different compositions by the Polymeric Precursor Method, which were thermally treated at very low temperatures in order to get amorphised powder samples. The zirconium-rich PZT6040 sample showed a significant uptake in photoluminescent emission between 320 oC and 350 oC, followed by a slightly increasing in bandgap energy. In spite of the bandgap energy posses the typical value for several structurally disordered semiconductors, these effects were associated to the coexistence of pyrochlore and tetragonal perovskite phases in that referred conditions.

Abstract: Many synthesis methods are available to obtain a set of specific characteristics for lead zirconate titanate (PZT) piezoelectric ceramic powders. In this work, we have successfully prepared PZT powder samples through the Polymeric Precursor Method with x = 0.6, according the general formula Pb (Zr_xTi_1-x)O₃. The powders were thermally treated from 380 to 550 oC and characterized by Raman spectroscopy and X-ray diffraction (DRX) in order to evaluate the effects of thermal treatment on the phase formation and the crystallization processes. The results obtained by Raman spectroscopy were compared to refined crystal data obtained by Rietveld method, leading to coherent conclusions about the structural effects occurring along the temperature of calcination. It was possible to characterize the tetragonal perovskite phase as predominant phase occurs only after 500 oC, but its crystallinity is already determined by synthesis method. Thus, no ordering process is verified for perovskite as a function of the temperature increasing during thermal treatment, in spite of the continuous pyrochlore-to-perovskite phase transition. The pyrochlore secondary phase starts to vanish before its proper crystallization process, changing the tetragonality of previously formed perovskite phase.

Abstract: Attractive for MEMS, PZT thick films are often microstructured on Si supporting platforms to span the gap between ceramics and thin film technologies. Printing process might lead to lower cost than ceramic process to open routes for MEMS applications. In this paper processing by screen-printing of Au/PZT/Au thick-films supported on alumina or completely released from the substrate are described. Investigations of the film microstructures nevertheless show lower densification than those of bulk ceramics. Prior to selective coating deposition, routes to improve the reduction of the film’s porosity are proposed.

Abstract: The aim of this work was to synthesize lead zirconate titanate, Pb(Zr_0.52Ti_0.48)O₃ (PZT) via Pechini method, to characterize the polymeric precursor through differential thermal analysis and thermogravimetric analysis, as well as to characterize the PZT powder through x-ray diffraction and scanning electron microscopy with energy-dispersive spectroscopy. In this work, the metallic precursors used during the PZT synthesis were titanium IV isopropoxide, zirconyl nitrate and lead nitrate; citric acid and ethylene glycol were used as chelating and polymerizing agents, respectively. The polymeric precursor was calcined at 800°C for two hours in a muffle oven. The main results showed that the polymeric precursor undergoes decomposition at approximately 316°C and PZT is crystallized around 722°C. It was confirmed that the PZT powder has chemical composition in the morphotropic phase boundary and its morphology consists of agglomerates of particles. Finally, it was proved that the PZT powder is crystalline, with the predominance of the tetragonal phase.

Abstract: In this work, the piezoelectric material system of Pb (Zr_0.52Ti_0.48)O₃ ceramics were synthesized by conventional solid state via high energy planetary mill reaction. This process were chosen in order to skip the calcinations and implement a single firing process which very effective to reduce the possibility of PbO loss. The effect of sintering parameters on structural behavior of pure PZT ceramic was discussed in detail. Comprehensive studies have been carried out in order get optimum parameter for sintering process, thus improved the performance of the pure PZT ceramics. Grain size properties of Pb (Zr_0.52Ti_0.48)O₃ ceramics increased with increasing the sintering temperature and duration. However longer sintering condition (1200 °C, 3 hours) causes excessive PbO loss which leads to presence new phases in XRD analysis, promote grain growth behavior with inhomogenous microstructure and tend to have more pores.

Abstract: Lead Zirconate Titanate (PZT) undoped and doped was prepared by using solid state reaction method. In this paper, PZT is doped with another elements with is La³⁺ and Sr²⁺ in order to enhance the properties of PZT. The samples were prepared via high planetary mill which is can skip the calcination process that can cause of PbO loss during firing. With the help of x-ray diffraction (XRD) and scanning electron microscopy (SEM), the formation of perovskite structure into newly modified ceramics was investigated and the grain growth of pure PZT and doped PZT were also investigated which is can enhance their properties which may be suitable for possible device applications.