Showing papers on "Piezoelectricity published in 2008"

Origin of morphotropic phase boundaries in ferroelectrics

Abstract: A piezoelectric material is one that generates a voltage in response to a mechanical strain (and vice versa). The most useful piezoelectric materials display a transition region in their composition phase diagrams, known as a morphotropic phase boundary, where the crystal structure changes abruptly and the electromechanical properties are maximal. As a result, modern piezoelectric materials for technological applications are usually complex, engineered, solid solutions, which complicates their manufacture as well as introducing complexity in the study of the microscopic origins of their properties. Here we show that even a pure compound, in this case lead titanate, can display a morphotropic phase boundary under pressure. The results are consistent with first-principles theoretical predictions, but show a richer phase diagram than anticipated; moreover, the predicted electromechanical coupling at the transition is larger than any known. Our results show that the high electromechanical coupling in solid solutions with lead titanate is due to tuning of the high-pressure morphotropic phase boundary in pure lead titanate to ambient pressure. We also find that complex microstructures or compositions are not necessary to obtain strong piezoelectricity. This opens the door to the possible discovery of high-performance, pure-compound electromechanical materials, which could greatly decrease costs and expand the utility of piezoelectric materials.

An Introduction to the Theory of Piezoelectricity

Abstract: Nonlinear Electroelasticity for Strong Fields.- Linear Piezoelectricity for Infinitesimal Fields.- Static Problems.- Vibrations of Finite Bodies.- Waves in Unbounded Regions.- Linear Equations for Small Fields Superposed on Finite Biasing Fields.- Cubic and Other Effects.- Piezoelectric Devices.

Piezoelectric and Acoustic Materials for Transducer Applications

Abstract: Fundamentals of Piezoelectricity- Thermodynamics of Ferroelectricity- Piezoelectricity and Crystal Symmetry- Crystal Chemistry of Piezoelectric Materials- Piezoelectric and Acoustic Materials for Transducer Technology- Lead-Based Piezoelectric Materials- KNN-Based Piezoelectric Ceramics- Bismuth-based Piezoelectric Ceramics- Electropolymers for Mechatronics and Artificial Muscles- Low-Attenuation Acoustic Silicone Lens for Medical Ultrasonic Array Probes- Carbon-Fiber Composite Materials for Medical Transducers- Transducer Design and Principles- Piezoelectric Transducer Design for Medical Diagnosis and NDE- Piezoelectric Transducer Designs for Sonar Applications- Finite Element Analysis of Piezoelectric Transducers- Piezoelectric Transducer Fabrication Methods- Piezoelectric Fiber Composite Fabrication- Composition Gradient Actuators- Robocasting of Three-Dimensional Piezoelectric Structures- Micropositioning- Piezoelectric Actuator Designs- Piezoelectric Energy Harvesting using Bulk Transducers- Piezocomposite Ultrasonic Transducers for High-Frequency Wire Bonding of Semiconductor Packages- Piezoelectric MEMS: Materials and Devices- High-Frequency Ultrasonic Transducers and Arrays- Micromachined Ultrasonic Transducers

Lead-free piezoceramics with giant strain in the system Bi0.5Na0.5TiO3–BaTiO3–K0.5Na0.5NbO3. I. Structure and room temperature properties

Abstract: Lead-free piezoelectric ceramics, 1� xyBi 0.5 Na 0.5 TiO 3 -xBaTiO 3 -yK 0.5 Na 0.5 NbO 3 0.05x 0.07 and 0.01y 0.03, have been synthesized by a conventional solid state sintering method. The room temperature ferroelectric and piezoelectric properties of these ceramics were studied. Based on the measured properties, the ceramics were categorized into two groups: group I compositions having dominant ferroelectric order and group II compositions displaying mixed ferroelectric and antiferroelectric properties at room temperature. A composition from group II near the boundary between these two groups exhibited a strain as large as 0.45% at an electric field of 8k V/ mm. Polarization in this composition was not stable in that the piezoelectric coefficient d33 at zero electric field was only about 30 pm/ V. The converse piezoelectric response becomes weaker when the composition deviated from the boundary between the groups toward either the ferroelectric or antiferroelectric compositions. These results were rationalized based on a field induced antiferroelectric-ferroelectric phase transition. © 2008 American Institute of Physics. DOI: 10.1063/1.2838472

Piezoelectricity: Evolution and Future of a Technology

Abstract: Basics and Materials.- Basic Material Quartz and Related Innovations.- The Role of Ferroelectricity for Piezoelectric Materials.- Piezoelectric PZT Ceramics.- Relaxor Ferroelectrics.- Piezoelectric Polymers and Their Applications.- Applications and Innovations.- Electromechanical Frequency Filters.- Ultrasonic Imaging.- High Effective Lead Perovskite Ceramics and Single Crystals for Ultrasonic Imaging.- High-Power Ultrasound Transducers for Therapeutic Applications.- Piezoelectric Motors and Transformers.- Piezoelectric Positioning.- Piezoelectric Injection Systems.- Advanced RF Signal Processing with Surface Acoustic Waves on Piezoelectric Single Crystal Substrates.- Piezoelectric Films for Innovations in the Field of MEMS and Biosensors.- Piezoelectric Composites by Solid Freeform Fabrication: A Nature-Inspired Approach.- Characterisation Methods.- Microstructural Analysis Based on Microscopy and X-Ray Diffraction.- Small Signal Resonance Methods.- Large Signal Resonance and Laser Dilatometer Methods.- Ferroelastic Characterization of Piezoelectrics.- Multiscale Modelling.- First-Principles Theories of Piezoelectric Materials.- Thermodynamic Theory.- Effective Medium Theories.- Finite-Element Modelling of Piezoelectric Actuators: Linear and Nonlinear Analyses.- The Future.- Trends in Ferroelectric/Piezoelectric Ceramics.

Giant piezoelectric d33 coefficient in ferroelectric vanadium doped ZnO films

Abstract: A giant electromechanical d33 coefficient 110pC∕N is obtained in ferroelectric V-doped ZnO films, which is nearly one order of magnitude higher than that of undoped samples. It is considered that the switchable spontaneous polarization induced by V dopants and the accompanying relatively high permittivity should be responsible for the enhancement of piezoelectric response. Moreover, from another point of view, an easier rotation of V–O bonds which are noncollinear with c axis under electric field might be the microscopic origin of this anomaly. The improved piezoelectric properties could make V-doped ZnO a promising candidate for piezoelectric devices.

Handbook of Advanced Dielectric, Piezoelectric and Ferroelectric Materials : Synthesis, Properties and Applications

Abstract: Part 1 High strain high performance piezo- and ferroelectric single crystals: Bridgman growth and properties of PMN-PT single crystals Flux growth and characterization of PZN-PT and PMN-PT single crystals Recent developments and applications of Piezo crystals Piezoelectric single crystals for medical ultrasonic transducers High performance, high-TC piezoelectric crystals Development of high performance piezoelectric single crystals by using solid-state single crystal growth (SSCG) method Piezo- and ferroelectric (1-x)Pb(Sc1/2Nb1/2)O3?xPbTiO3 solid solution system High-curie temperatures piezoelectric single crystal of the Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 ternary materials system. Part 2 Field-induced effects and domain engineering: Full set material properties and domain engineering principles of ferroelectric single crystals Domain wall engineering in piezoelectric crystals with engineered domain configuration Enhancement of piezoelectric properties in perovskite crystals by thermally, compositionally, electric field and stress induced instabilities Electric-field-induced domain structures and phase transitions in PMN-PT single crystals Energy analysis of field induced phase transitions in relaxor-based piezo- and ferroelectric crystals. Part 3 Morphotropic phase boundary and related phenomena: From the structure of relaxor to the structure of MPB systems Size effects on the macroscopic properties of the relaxor-ferroelectric Pb(Mg1/3Nb2/3)O3-PbTiO3 solid solution. Part 4 High power piezoelectric and microwave dielectric materials: Loss mechanisms and high power piezoelectric components Bismuth-based pyrochlore dielectric ceramics for microwave applications. Part 5 Nanoscale piezo- and ferroelectrics: Ferroelectric nanostructures for device applications Domains in ferroelectric nanostructures from first principles Nanosized ferroelectric crystals Nano- and micro-domain engineering in normal and relaxor ferroelectrics Interface control in 3D ferroelectric nano-composites. Part 6 Piezo- and ferroelectric films: Single crystalline PZT Films and the impact of extended structural defects on the ferroelectric properties Piezoelectric thick films for MEMS application Symmetry engineering in ferroelectric thin films. Part 7 Novel processing and new materials: Processing of textured piezoelectric and dielectric perovskite-structured ceramics by reactive-templated grain growth method Grain orientation and electrical properties of bismuth layer-structured ferroelectrics Novel solution routes to ferroelectrics and relaxors Room temperature preparation of KNbO3 nanoparticles and thin film from a perovskite nanosheet Lead-free relaxors. Part 8 Novel properties of ferroelectrics and related materials: Novel physical effects in dielectric superlattices and their applications Dielectric and optical properties of perovskite artificial superlattices Crystal structure and defect control in Bi4Ti3O12-based layered ferroelectric single crystals.

Structural and functional properties of screen-printed PZT–PVDF-TrFE composites

Abstract: Thick films of 0–3 composites of lead–zirconate–titanate (PZT) particulate and polyvinylidene-trifluoroethylene (PVDF-TrFE) copolymer have been produced by screen-printing on indium–tin-oxide (ITO)-coated glass substrates. The microstructure was investigated using scanning electron microscopy and X-ray diffraction. The dependences of the dielectric properties of the composites on PZT volume fraction are reported and analyzed in terms of an analytical model. The pyroelectric properties were determined using dynamical experimental setups, and are given in terms of pyroelectric coefficient and figures of merit. The piezoelectric response was investigated as a function of the PZT volume fraction using a laser vibrometer. The piezoelectric charge coefficient, d 33,eff , is shown to exhibit a minimum at a PZT volume fraction of 40% which arises from the piezoelectric charge coefficients of the pure constituents being of opposite sign. It is thought that screen-printing of these composites constitutes a cost-effective way of producing structured functional thin films for pyroelectric and piezoelectric applications.

Mechanical-Electrical Triggers and Sensors Using Piezoelectric Micowires/Nanowires

Abstract: We demonstrate a mechanical−electrical trigger using a ZnO piezoelectric fine-wire (PFW) (microwire, nanowire). Once subjected to mechanical impact, a bent PFW creates a voltage drop across its width, with the tensile and compressive surfaces showing positive and negative voltages, respectively. The voltage and current created by the piezoelectric effect could trigger an external electronic system, thus, the impact force/pressure can be detected. The response time of the trigger/sensor is ∼10 ms. The piezoelectric potential across the PFW has a lifetime of ∼100 s, which is long enough for effectively “gating” the transport current along the wire; thus a piezoelectric field effect transistor is possible based on the piezotronic effect.

Piezoelectric and ferroelectric properties of Bi-compensated (Bi1/2Na1/2 )TiO3-(Bi1/2K1/2)TiO3 lead-free piezoelectric ceramics

Abstract: (Bi1/2Na1/2)TiO3–(Bi1/2K1/2)TiO3 (BNT-BKT) ceramics as a promising candidate for lead-free piezoelectric ceramics were studied with a special emphasis on the compositional dependence of piezoelectric and ferroelectric properties. One mole percent excess Bi was added to compensate for the volatilization of Bi3+ ions during sintering, which was found to be effective in improving the piezoelectric properties of the resultant BNT-BKT ceramics. The piezoelectric, ferroelectric, and dielectric properties of the Bi-compensated BNT-BKT ceramics were investigated and discussed in relation to the morphotropic phase boundary that is close to the composition range of 20–24 mol % BKT. The maximum piezoelectric constant d33 (207 pC/N) and electromechanical coupling factor kp (35%) were obtained at the compositions of 23% and 20%, respectively.

Sodium Niobate Nanowire and Its Piezoelectricity

Abstract: Nanowires of crystalline orthorhombic sodium niobate (NaNbO3), with diameters of approximately 100 nm and lengths of several to hundreds of microns, as well as cubes with edges of lengths of hundreds of nanometers were obtained by reacting niobium oxide (Nb2O5) with 10 and 12.5 M NaOH solutions, respectively. The microstructures of the synthesized wiry and cubic piezoelectric materials were investigated, and the details of the reactions were elucidated as well. The piezoelectricity of individual NaNbO3 (Pbma) nanowires was confirmed by piezoresponse force microscopy, and an effective piezoelectric coefficient along the vertical direction of around a few pm/V was obtained. To our knowledge, the present work is the first report of the preparation of NaNbO3 nanowires as well as the determination of piezoelectricity.

A review on the three-dimensional analytical approaches of multilayered and functionally graded piezoelectric plates and shells

Abstract: The article is to present an overview of various three-dimensional (3D) analytical approaches for the analysis of multilayered and functionally graded (FG) piezoelectric plates and shells. The reported 3D approaches in the literature are classified as four different approaches, namely, Pagano’s classical approach, the state space approach, the series expansion approach and the asymptotic approach. Both the mixed formulation and displacement-based formulation for the 3D analysis of multilayered piezoelectric plates are derived. The analytical process, based on the 3D formulations, for the aforementioned approaches is briefly interpreted. The present formulations of multilayered piezoelectric plates can also be used for the analysis of FG piezoelectric plates, of which material properties are heterogeneous through the thickness coordinate, by artificially dividing the plate as NL-layered plates with constant coefficients in an average sense for each layer. The present formulations can also be extended to the ones of piezoelectric shells using the associated shell coordinates. A comprehensive comparison among the 3D results available in the literature using various approaches is made. For illustration, the through-thickness distributions of various field variables for the simply-supported, multilayered and FG piezoelectric plates are presented using the asymptotic approach and doubly checked with a newly-proposed meshless method. The literature dealing with the 3D analysis of multilayered and FG piezoelectric plates is surveyed and included. This review article contains 191 references. 1 Corresponding author. Fax: +886-6-2370804, E-mail: cpwu@mail.ncku.edu.tw 2 Department of Civil Engineering, National Cheng Kung University, Taiwan, ROC Keyword: 3D solution; FG material; Piezoelectric material; Smart material; Shells; Plates

Dielectric, ferroelectric, and piezoelectric properties of the lead-free (1−x)(Na0.5Bi0.5)TiO3-xBiAlO3 solid solution

Abstract: Lead-free piezoelectric ceramics derived from the solid solution of (1−x)(Na05Bi05)TiO3–xBiAlO3 (NBT-BA) (x=0–010) have been synthesized by solid state reactions A pure perovskite phase was formed for x≤008 The temperature dependence of dielectric constant indicates an increased broadness of the dielectric peak as the amount of BA increases The large dielectric loss of NBT ceramics at low frequency and high temperature has been significantly reduced by the substitution of BA The high coercive field is decreased and ferroelectric hysteresis loops were displayed at room temperature The NBT-BA ceramics exhibit improved ferroelectric and piezoelectric properties compared to pure NBT ceramics, with Pr=52 μC/cm2, Ec=44 kV/cm, d33=130 pC/N, and kp=023 for 092NBT–008BA

Equivalent circuit method for static and dynamic analysis of magnetoelectric laminated composites

Abstract: Magnetoelectric equivalent circuit analytical method is presented for laminate composites of magneto-strictive Terfenol-D (TbxDy1−xFe2) and piezoelectric Pb(Zr1−xTix)O3 (PZT) operated in longitudinal magnetized and transverse polarized (or L-T), and transverse magnetized and transverse polarized (or T-T) modes. Magnetoelectric (ME) couplings both at low-frequency and resonance-frequency have been studied, and our analysis predicts that (i) the ME voltage coefficients of both L-T and T-T modes increase with increasing the thickness of the piezoelectric phase whereas magnetostrictive phase thickness keeps constant, and then tend to saturation when the thickness ratio of piezoelectric phase to magnetic phases is >3; (ii) there are the optimum thickness ratios that maximize magnetoelectric (ME) voltage coefficients for the two modes, which are dependent on elastic compliances ratio of piezoelectric phase and magnetostrictive phase; and (iii) the ME voltage coefficients are dramatically increased by a factor of ∼Qm, when operated at resonance frequency. A series of Terfenol-D/PZT laminates were fabricated, and the results were compared with the theoretical ones. Experiments confirmed that equivalent circuit method is a useful tool for optimum designs of ME laminates.

Resonant magnetoelectric response of magnetostrictive/piezoelectric laminate composite in consideration of losses

Abstract: The magnetostrictive/piezoelectric (MP) laminate composite has dramatically enhanced magnetoelectric (ME) effect when operating around resonance. The theoretical analysis of the resonant ME effect is investigated using the equivalent circuit method, in which the eddy current loss, the mechanical loss and the electric loss are all taken into account. The results indicate that, the mechanical loss plays a primary role in dissipations in resonant status, and a strong bias magnetic field is essential to restrain eddy current loss and improve the ME conversion efficiency.

Piezoelectric thin film, piezoelectric material, and fabrication method of piezoelectric thin film and piezoelectric material, and piezoelectric resonator, actuator element, and physical sensor using piezoelectric thin film

Abstract: A piezoelectric thin film of the present invention includes an aluminum nitride thin film that contains scandium. A content ratio of scandium in the aluminum nitride thin film is 0.5 atom % to 50 atom % on the assumption that a total amount of the number of scandium atoms and the number of aluminum atoms is 100 atom %. According to this arrangement, the piezoelectric thin film of the present invention can improve a piezoelectric response while keeping characteristics of elastic wave propagation speed, Q value, and frequency-temperature coefficient that the aluminum nitride thin film has.

Enhanced magnetoelectric effect in longitudinal-transverse mode Terfenol-D∕Pb(Mg1∕3Nb2∕3)O3–PbTiO3 laminate composites with optimal crystal cut

Abstract: Magnetoelectric (ME) laminate composite consisting of optimal crystal cut thickness-polarized piezoelectric 0.7Pb(Mg1∕3Nb2∕3)O3–0.3PbTiO3 (PMN-PT) single crystal and the length-magnetized magnetostrictive Tb0.3Dy0.7Fe1.92 (Terfenol-D) alloy has been fabricated. The cut optimization of PMN-PT crystal greatly enhances the longitudinally magnetized-transversely polarized (L‐T) mode ME effect, which has a superior ME voltage coefficient αE of ∼3.02V∕cmOe in low frequency band. Near the resonance frequency of 95kHz, the coefficient dramatically increases and reaches the maximized value of 33.2V∕cmOe, which is almost two times larger than the previously reported ⟨001⟩-oriented PMN-PT crystal based L‐T mode laminate composite.

Piezoelectric K0.5Na0.5NbO3 thick films derived from polyvinylpyrrolidone-modified chemical solution deposition

Abstract: Lead-free K0.5Na0.5NbO3 (KNN) ferroelectric films with enhanced thickness of 3.5 μm were prepared by a polyvinylpyrrolidone-modified chemical solution deposition method. A single perovskite phase with a dense morphology and (100) orientation was obtained at relatively low annealing temperature of 600 °C. A large effective piezoelectric coefficient d33, of 61 pm/V was demonstrated at 100 kHz without considering the substrate clamping effect. A well-saturated polarization hysteresis loop was obtained with a high remnant polarization Pr of 16.4 μC/cm2. These results showed that KNN is a promising lead-free piezoelectric film candidate, and that crystallizing the film at low processing temperature to obtain (100) orientation and dense morphology is critical to achieving excellent ferroelectric and piezoelectric properties.

Piezoelectricity and Crystal Symmetry

Abstract: In this chapter, the symmetry aspects of the piezoelectric effect in various materials (single crystals, ceramics, and thin films) are briefly overviewed. First, the third-rank tensor of piezoelectric coefficients defined in the crystallographic reference frame is discussed. On this basis, the orientation dependence of the longitudinal piezoelectric response in ferroelectric single crystals is described. This dependence is especially important for relaxor single crystals, where a giant piezoelectric effect is observed. Then, the effective piezoelectric constants of polydomain crystals, ceramics, and thin films and their dependence on crystal symmetry are discussed. The domainwall contribution to the piezoelectric properties of ferroelectric ceramics and thin films is also described. Finally, the crystallographic principles of piezomagnetic, magnetoelectric, and multiferroic materials are presented.

History and Challenges of Barium Titanate: Part II

Abstract: Barium titanate is the first ferroelectric ceramics and a good candidate for a variety of applications due to its excellent dielectric, ferroelectric and piezoelectric properties. Barium titanate is a member of a large family of compounds with the general formula ABO3 which is called perovskite. Barium titanate can be prepared using different methods. The synthesis method depends on the desired characteristics for the end application and the method used has a significant influence on the structure and properties of barium titanate materials. In this review paper, in Part II the properties of obtained materials and their application are presented.

High-temperature poling of ferroelectrics

Abstract: The poling behavior of a lead-zirconate-titanate piezoelectric ceramic is investigated by measurements of the ferroelectric hysteresis, the longitudinal piezoelectric coefficient, and field-cooling poling experiments. At high temperatures, the decrease in the coercive field facilitates poling at lower electric fields, resulting in higher values of the longitudinal piezoelectric coefficient. However, there exists a threshold field of about 150 V/mm, below which fully poled samples cannot be obtained even when field cooling from temperatures above the transition. Further, a temperature regime below the Curie temperature is observed, where a polarization under field can be measured, but a remanent polarization is not stable. The results are discussed with respect to the phase transition behavior.

Design and electrical properties’ investigation of (K0.5Na0.5)NbO3–BiMeO3 lead-free piezoelectric ceramics

Abstract: Based on the discussion on the “origin” of the high piezoelectric properties of Pb-based piezoelectric ceramics, it was predicted that (K0.5Na0.5)NbO3–BiMeO3 solid solutions (where Me3+=Sc, Al, Ga, Y, In, etc.) should possess high piezoelectric properties because of the formation of the morphotropic phase boundary and the hybridization between the Bi 6p and O 2p orbits. (1−x)(K0.5Na0.5)NbO3–xBiScO3 [(1−x)KNN-xBS] ceramics were selected as an example to verify this prediction. (1−x)KNN-xBS ceramics were synthesized by conventional solid-state sintering. The phase structure, microstructure, and dielectric and piezoelectric properties of (1−x)KNN-xBS ceramics were investigated. At room temperature, the polymorphic phase transition (PPT) (from the orthorhombic to the tetragonal phase) in (1−x)KNN-xBS ceramics is identified at x=0.0175 by the analysis of x-ray diffraction patterns and dielectric spectroscopy. The ceramics (x=0.0175) with PPT near room temperature exhibit excellent electrical properties (d33=∼2...

A resonant frequency tunable, extensional mode piezoelectric vibration harvesting mechanism

Abstract: Electrical power for distributed, wireless sensors may be harvested from vibrations in the ambient through the use of electromechanical transducers. To be most useful, the electromechanical transducer should maximize the harvested power by matching its resonant frequency to the strongest vibration amplitude in the source's vibration spectrum. This paper introduces a new frequency tunable mechanism wherein the deformation of the piezoelectric elements is primarily in-plane extension, and bending effects may be neglected. The extensional mode resonator (XMR) is formed by suspending a seismic mass with two piezoelectric sheets. The mechanism is made frequency tunable by an adjustable link that symmetrically pre-tensions both piezoelectric sheets. A prototype XMR has been built and tested that has demonstrated adjustable and repeatable resonant frequency variation from 80 to 235 Hz. The electrical power generated by the XMR is also insensitive to the driving frequency, when the resonant frequency is matched to the driving frequency.