Properties Of PZT Research Articles

Structure and electrical properties of new Pb(Zr,Ti)O3–Pb(Fe2 / 3W1 / 3)O3–Pb(Mn1 / 3Nb2 / 3)O3 ceramics

A new piezoelectric material, Pb(Zr,Ti)O3–Pb(Fe2/3W1/3)O3–Pb(Mn1/3Nb2/3)O3 (PZT–PFW–PMN) ceramics, was prepared by conventional mixed-oxide method. Effects of Pb(Fe2/3W1/3)O3 (PFW) content on phase structure, microstructure, dielectric and piezoelectric properties of PZT–PFW–PMN ceramics were studied. It indicates that substitution of Pb(Fe2/3W1/3)O3 is effective on forming the solid solution and inhibiting the formation of pyrochlore phase. The proper addition of Pb(Fe2/3W1/3)O3 can promote the grain growth of the ceramics and make the ceramics have a high density. The dielectric and piezoelectric properties are also enhanced by adding Pb(Fe2/3W1/3)O3 into PZT–PMN. The 0.90PZT–0.03PFW–0.07PMN ceramics exhibit optimized properties. The dielectric and piezoelectric properties of this composition are as follows: d33=358 pC/N, Kp=0.63, Qm=1655, tanδ=0.0053, ɛr=1745 and Tc=273 °C, which show that this system is a new promising material for high power piezoelectric transformers application.

Electrical properties of undoped PZT and Co‐doped PCZT films deposited on ITO/glass substrates by a sol–gel method

AbstractPb(Zr0.5Ti0.5)O3 (PZT) and Co‐doped Pb(Zr0.5Ti0.5)O3 (PCZT) thin films have been fabricated on ITO/glass substrates by a sol–gel method combined with a rapid thermal annealing process. The films were polycrystalline with (101)‐preferred orientation. The experiments found that the addition of cobalt in PZT films greatly improved the ferroelectric properties of PZT thin films. Large remanent polarization and small coercive field were confirmed by P–E hysteresis loop measurements. The values for PZT films and PCZT films with 10 mol% Co‐doped annealed at 600 °C were 36.5 µC/cm2 and 45.2 kV/cm, 58.6 µC/cm2 and 67.3 kV/cm, respectively. Also, dielectric properties and I–V properties of PCZT films were revealed to be sensitive to the content of cobalt. The loss factor was higher for PCZT than for PZT films. The same behavior was obtained for the leakage current density. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Preparation and properties of PZT–PMN–PMS ceramics by molten salt synthesis

Piezoelectric powders and ceramics with a composition of Pb 0.95Sr 0.05 (Zr 0.52Ti 0.48) O 3–Pb(Mg 1 / 3 Nb 2 / 3 )O 3–Pb(Mn 1 / 3 Sb 2 / 3 )O 3 (PZT–PMN–PMS) were prepared by the molten salt synthesis (MSS) method. It was found that the MSS method significantly improved the sinterability of PZT–PMN–PMS ceramics, resulting in a reduction of sintering temperature by about 100 °C compared to the conventional mixed-oxide (CMO) method. The optimum values of d 33, K p, Q m and tan δ were 244 pC/N, 0.53, 1034 and 0.0090, respectively, at calcination of 800 °C and sintering of 1050 °C.

A study of the dielectric properties of PZT and PT ceramics depending on the lattice distortion

Depending on the lattice distortion, the dielectric properties of PZT and PT ceramics are studied from a structural phase transition point of view. The study involves a more profound physical process than the study of the relation between the dielectric properties and composition x. Two equations connecting the dielectric properties and the lattice distortions are established in the tetragonal and rhombohedral phase regions. In particular, the relation between the dielectric properties and the lattice distortion is investigated in the phase coexistence region of PZT ceramics using a phase statistical distribution model, and we determine the fitting value of the volume fraction of the tetragonal phase VTto composition x in the equation. All the fitting results indicate that our results are very consistent with the related experimental data for PZT and PT ceramics.PACS Nos.: 64.70.–p, 77.22.–d, 77.84.–s

Structural Properties of PZT(80/20) Thick Films Fabricated by Screen Printing Method

Pb(Zr<TEX>$_{0.8}$</TEX>Ti<TEX>$_{0.2}$</TEX>)O<TEX>$_{3}$</TEX> powders, prepared by the sol-gel method, were mixed with an organic vehicle and the PZT thick films were fabricated by the screen-printing techniques on Pt/Ah03 substrates. The structural properties were examined as a function of sintering temperature. The particle size distribution of the PZT powder derived from the sol-gel process is uniform with the mean particle size of about 2.6 m. As a result of the DTA, the formation of the polycrystalline perovskite phase was observed at around <TEX>$890^{circ}$</TEX>CC. In the X-ray diffraction analysis, all PZT thick films showed a perovskite polycrystalline structure without a pyrochlore phase. The perovskite crystallization temperature of PZT thick films was about <TEX>$890^{circ}$</TEX>C. The average thickness of the PZT thick films was approximately 80-90 m.

Piezoelectric and magnetic properties of PZT-(Ni0.284Zn0.549Cu0.183)Fe1.984O4 composites

The piezoelectric/piezomagnetic composite, PZT/Ni0.284Zn0.549Cu0.183Fe1.984O4, was fabricated by the mixed oxide method. The phase assemblage, piezoelectric strain constant and saturation magnetization were investigated. The results indicate that the PZT phase is compatible with Ni0.284Zn0.549Cu0.183Fe1.984O4 phase, and dense diphasic ceramic composites were obtained. It is found that piezoelectric strain constant decreases exponentially as the amount of doped piezomagnetic materials in the composite increases. Correspondingly, saturation magnetization of the composite also decreases with the increasing weight fraction of piezoelectric materials. Three reasons cause the results. First, the grain growth of piezomagnetic phase at the co-sintering temperature reduces grain size and continuity of the piezoelectric phase. Second, the pore size and porosity in composite increase dramatically with increasing amount of piezomagnetic phase. Third, the low resistivity of the composite prevents the poling process and reduces the piezoelectric strain constant. The tailoring of microstructure to achieve a high performance piezoelectric/piezomagnetic composite is proposed based on the analysis.

Analysis of the electrical properties of PZT by a BP artificial neural network

Artificial neural networks (ANN) constitute a recently emerged intriguing data processing technique. Over the last decade chemistry became a field of their wide application. Nevertheless, few has been known of the application of ANN modeling technique in inorganic ceramic materials. Based on the homogeneous experimental design the experimental results of 21 samples were analyzed by a three-layer BP (back propagation) network. Influence of the additives on the properties of the materials were illustrated by the registered ANN model. The basic reasons for the relationships between the additives and the electrical properties of the materials produced by the ANN model were also explained by the doping theory for piezoelectric ceramics. The optimized formulation was calculated and examined. The precise prediction results indicate that the three-layer BP network based modeling is a practically very useful tool in both property analysis and formulation design of the multicomponent oxide ceramic material.

On the evolution of the linear material properties of PZT during loading history—an experimental study

Ferroelectrics exhibit material behavior which is strongly affected by its loading history. Among other phenomena, the coefficients describing the linear material behavior are known to change when the state of polarization is altered. There are several approaches to modeling ferroelectric/ferroelastic behavior. However, with all models, assumptions have to be made on how the linear coefficients depend on the state of polarization. Often the elastic and dielectric coefficients are defined to be constant for the sake of simplicity. Alternatively, their evolution and that of the piezoelectric constants are described rather intuitively, while systematic experimental data are sparse. The present study explores the impact of large signal mechanical and electrical loading on the low frequency linear response of a soft PZT ceramic. This is accomplished via cyclic tests with progressively increasing maximum electrical or mechanical load. Upon load reversal, the quasi-linear response is measured. Remanent polarization and remanent strain are used as internal variables to describe the material behavior as a function of loading history. While the dielectric permittivity κ 33 is shown to exhibit only minor variation, Young’s modulus and the piezoelectric coefficient d 33 change significantly in the course of loading.

Application driven industrial development of piezoceramics

For more than 40 years, PZT family has been the best established group of piezoelectric ceramics, with a wide variety of compositions, optimised for different applications. It has been divided into hard and soft materials, each of the main groups divided again into subgroups, standardised and widely available in these classical types. The recent developments within the medical field includes, besides 3D diagnostics, new therapeutical applications using high intensity focused ultrasound (HIFU), requires for the latter a hard material type to handle necessary signal level. However, it is also desirable to have, at the same time, higher dielectric constant in order to match electrical impedance. Besides electrical matching, acoustic properties of ceramics are important in order to optimise performance of transducers based on PZT. Mismatch between acoustic properties of PZT and environments, in which transducers have to work, have been overcome by adding matching layers a/o backing and creating composite structure using time consuming and costly dice and fill processes or similar. Finally, high content of lead in PZT has in the light of EU's environmental policy towards sustainable materials, a substantial effort was made to replace PZT by lead free materials. This paper presents, besides two new hard materials with dielectric constant of 1900 and 2800, also an additional version of these materials with engineered structure, where the acoustic impedance has been reduced to approximately15 M Rayleigh. Typical properties for the new materials including lead free ceramics will be presented.

Effect of excess Pb on crystallinity and ferroelectric properties of PZT(40/60) films on LaNiO 3 coated Si substrates by MOD technique

Pb(Zr 0.4Ti 0.6)O 3 [PZT(40/60)] films were deposited onto LaNiO 3 (LNO) coated Si substrates by metal-organic decomposition (MOD) technique. Excess Pb was incorporated in the film by using excess Pb (2%–15%) in the solution. The crystallinity and ferroelectric properties of PZT films were investigated by using X-ray diffraction (XRD), RT66A test system and HP4194 impedance analyzer, respectively. Rayleigh law was employed to analyze the defect concentration in the films. The results show that all the PZT films show the (1 0 0) preferential orientation with complete perovskite structure except for the 2% film displaying some pyrochlore phase. The (1 0 0) preferential orientation is mainly attributed to LNO bottom electrode, which has the highly (1 0 0) preferential orientation. The 10% film shows the best polarization and dielectric properties. The remnant polarization and coercive field are about 10.1 μC/cm 2 and 73 kV/cm under an electric field around 330 kV/cm, respectively. And the dielectric constant and dissipation factor are about 656 and 0.022 at a frequency of 1 kHz, respectively. The good ferroelectric properties of the 10% film are mainly attributed to the low defect concentration in the film.

Effects of complex additives on toughness and electrical properties of PZT ceramics

This paper investigates the influence of complex additives on the toughness and electrical properties of doped PZT. Properties of doped PZT ceramics were found to be greatly influenced by their microstructures, second phases, domain size, domain configuration and domain wall mobility due to presence of the additives. The presence of dopant appeared to assist densification. Due to the combined effects of the presence of second phases, energy dissipation in the ferroelastic domains, high density as well as changes in grain size, the fracture toughness of the doped PZT was increased. With suitable additives, the present study has demonstrated that dielectric and piezoelectric properties of doped PZT could be improved.

Piezoelectric characteristics of spray dried PLZT ceramics modified by sodium

Lead zirconate titanate [Pb (Zr, Ti)O3] ceramics modified with lanthanum (PLZT) have been studied by numerous investigators in order to modify the properties of the materials for wide applications in various piezoelectric, electrooptic, ultrasonic, and underwater devices along with actuators, sensors, and smart devices in different fields of science and technology [1–5]. It is well known that the electromechanical properties of PZT depend strongly on additives [6] as well as the morphotropic phase boundary [7]. It has been reported that the electromechanical properties of PZT ceramics could be enhanced by substitution of La3+ on the basis of easy domain wall motion taking place due to the formation of A-site vacancies [8]. In addition, it has also been reported that La3+ additives influence poling efficiency and consequently the piezoelectric activities of the pure PZT ceramics. (Pb, La) (Zr, Ti)O3 [PLZT] with 2 at.% La+ and Zr/Ti ratio 53/47, being in the vicinity of morphotropic phase boundary (MPB), has shown better dielectric and piezoelectric properties. Much work has been reported on PLZT for dielectric and piezoelectric applications but work on the effect of addition of alkali ions Na+ at A-site of PZT along with La3+ (PLNZT) near MPB has rarely been reported. The present investigation was, therefore, undertaken to study the role of Na+ ions on the dielectric and piezoelectric properties of PLZT prepared with spray drying technique. Powders of PLZT and Na+-doped PLZT (PLNZT) of the following compositions were prepared by spray drying the composite nitrate solutions of the constituents:

Hydrothermal synthesis of doped PZT powders: sintering and ceramic properties

We present here the sintering behaviour, the ceramic characteristics and the electrical properties of PZT prepared from new hydrothermal powders. These results are compared with classical calcined ceramic properties. PZT powders are doped corresponding to the formula Pb((Zr 0.49Ti 0.51) 0.94Mn 0.0252Sb 0.0192W 0.0156)O 3 with or without 0.8758 mol% Ni.

입자 크기가 PZT계 압전 후막의 물성에 미치는 영향

입자 크기가 PZT계 압전 후막의 물성에 미치는 영향

Hydrothermal synthesis of doped PZT powders: sintering and ceramic properties

We present here the sintering behaviour, the ceramic characteristics and the electrical properties of PZT prepared from new hydrothermal powders. These results are compared with classical calcined ceramic properties. PZT powders are doped corresponding to the formula Pb((Zr 0.49 Ti 0.51 ) 0.94 Mn 0.0252 Sb 0.0192 W 0.0156 )O 3 with or without 0.8758 mol% Ni.

Annealing Temperature Effect of PbZr&lt;sub&gt;0.4&lt;/sub&gt;Ti&lt;sub&gt;0.6&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; Film on La&lt;sub&gt;1/2&lt;/sub&gt;Sr&lt;sub&gt;1/2&lt;/sub&gt;CoO&lt;sub&gt;3&lt;/sub&gt; Bottom Electrode

We have investigated the ferroelectric and electrical properties of PZT 40/60 films on the bottom La1/2Sr1/2CoO3(LSCO) electrode. The LSCO bottom electrode was sputtered on the SiO2/Si(100). As the annealing temperature of PZT capacitors on the LSCO is increased, the ferroelectric properties gradually increase with the annealing temperature up to 650°C. However, for the PZT capacitors annealed above 650°C, electrical measurement cannot be performed.

Structural and Electrical Properties of Pb(Zr,Ti)O3 Thin Films on GaN/Sapphire, Ru/Sapphire and Ru/GaN/Sapphire Substrates

Lead zirconate titanate or Pb(Zr0.3Ti0.7)O3 thin films were deposited on GaN, Ru/Sapphire and Ru/GaN/Sapphire substrates by the sol-gel technique. The Ru films, with a (002) preferred orientation, were deposited by metalorganic chemical vapor deposition (MOCVD) on Sapphire (0001) and GaN/Sapphire substrates. The properties of PZT on Ru films, rapid thermal annealed under different conditions, are investigated. The P-E hysteresis curves and C-V data for PZT films on Ru/GaN and Ru/Sapphire substrates were measured as a function of voltage and frequency. The Metal-Ferroelectric-Semiconductor (MFS or Pt/PZT/GaN) structures, prepared by depositing PZT thin films on n-type (Si doping ∼1×1018 cm−3) and (0001)-GaN/Sapphire, were characterized for their dielectric properties. The PZT films on as-deposited Ru, as opposed to annealed Ru, exhibit improved properties; remnant polarization of 37 μC/cm2, dielectric permittivity of 425 at 100 KHz, and leakage current density ∼1×10−7 A/cm2 at 1.5 V.

Pb(Zr,Ti)O3-GaN Heterostructures for RF MEMS Applications

Ferroelectric (Pb(Zr0.3Ti0.7)O3 or PZT(30/70))/GaN/Sapphire heterostructures were fabricated by the sol-gel process. The structure and composition of PZT, and its dielectric and ferroelectric properties in Pt/PZT/Ru or Pt/PZT/Pt, and Pt/PZT/GaN configurations were characterized to assess their feasibility as RF MEMS devices for eventual insertion in RF communication systems. The X-ray diffraction and pole figure analysis confirmed the stoichiometric, phase-pure PZT with (111) out-of-plane relationship on (0001) GaN. The secondary ion mass spectrometry (SIMS) depth profile indicated a stable interface with insignificant inter-diffusion of the Pb, Zr, or Ti elements into the GaN. The properties of PZT in Pt/PZT/Ru/GaN or MFM configuration were high capacitance density (C/A = 1.25 μF/cm2) and polarization (30 μC/cm2). In contrast, PZT in Pt/PZT/GaN or MFS configuration exhibited lower capacitance density (C/A = 0.35 μF/cm2) and asymmetrical hysteresis loops (polarization ∼4 μC/cm2). From the calculated spatial distribution of the electric field, E(x), and potential, V(x), which stem from all the charge densities within the entire MFS system, one may eventually design and fabricate PZT/GaN heterostructures in terms of controllable parameters (e.g., PZT phase and orientation, donor and acceptor ionization energies, and thickness and screening lengths of PZT and GaN), such that the depolarization field (Edepol) is minimized and the polarization is maximized in PZT.

結晶均質化法に基づいたPZT単結晶体の物性同定(OS9a 先端材料の機能性評価と材料設計に関する数理解析)

結晶均質化法に基づいたPZT単結晶体の物性同定(OS9a 先端材料の機能性評価と材料設計に関する数理解析)

Effects of addition of Pb(Y 1/2Nb 1/2)O 3 (PYN) on microstructure and piezoelectric properties of Pb(Zr 0.53Ti 0.47)O 3

Pure and Pb(Y 1/2Nb 1/2)O 3 (PYN)-doped Pb(Zr 0.53Ti 0.47)O 3 have been characterized. The samples were prepared by conventional mixed-oxide ceramic technology. PYN dopant was added to PZT at content levels ranging from 1 to 2.5 mol%. The microstructures of the samples were examined using SEM and TEM. The average grain size was observed to decrease as the dopant content increased. Herringbone-like and wedge-shaped domain patterns were observed in all the samples. The piezoelectric properties of PZT were greatly improved by the addition of PYN. The highest piezoelectric constant d 31 was nearly twice that of pure PZT.