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Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Issue 9 • Date September 2011

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  • "IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control - Front cover"

    Publication Year: 2011 , Page(s): c1 - c2
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  • IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society

    Publication Year: 2011 , Page(s): c3
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  • IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society - Elected Administrative Committee

    Publication Year: 2011 , Page(s): c4
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  • Table of contents

    Publication Year: 2011 , Page(s): i - ii
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  • Information for contributors with multimedia addition

    Publication Year: 2011 , Page(s): 1707 - 1710
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  • A multimedia example

    Publication Year: 2011 , Page(s): 1711
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  • Introduction to the special issue on the joint meeting of the 19th IEEE International Symposium on the Applications of Ferroelectrics and the 10th European Conference on the Applications of Polar Dielectrics

    Publication Year: 2011 , Page(s): 1712 - 1713
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    The joint meeting of the 19th IEEE International Symposium on the Applications of Ferroelectrics and the 10th European Conference on the Applications of Polar Dielectrics took place in Edinburgh from August 9-12, 2010. The conference was attended by 390 delegates from more than 40 different countries. There were 4 plenary speakers, 56 invited speakers, and a further 222 contributed oral presentations in 7 parallel session. In addition there were 215 poster presentations. Key topics addressed at the conference included piezoelectric materials, leadfree piezoelectrics, and multiferroics. View full abstract»

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  • Determination of the reduced matrix of the piezoelectric, dielectric, and elastic material constants for a piezoelectric material with C symmetry

    Publication Year: 2011 , Page(s): 1714 - 1720
    Cited by:  Papers (5)
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    We present a procedure for determining the reduced piezoelectric, dielectric, and elastic coefficients for a C material, including losses, from a single disk sample. Measurements have been made on a Navy III lead zirconate titanate (PZT) ceramic sample and the reduced matrix of coefficients for this material is presented. In addition, we present the transform equations, in reduced matrix form, to other consistent material constant sets. We discuss the propagation of errors in going from one material data set to another and look at the limitations inherent in direct calculations of other useful coefficients from the data. View full abstract»

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  • Analysis of nonlinear transient responses of piezoelectric resonators

    Publication Year: 2011 , Page(s): 1721 - 1729
    Cited by:  Papers (2)
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    The electric transient response method is an effective technique to evaluate material constants of piezoelectric ceramics under high-power driving. In this study, we tried to incorporate nonlinear piezoelectric behaviors in the analysis of transient responses. As a base for handling the nonlinear piezoelectric responses, we proposed an assumption that the electric displacement is proportional to the strain without phase lag, which could be described by a real and constant piezoelectric e-coefficient. Piezoelectric constitutive equations including nonlinear responses were proposed to calculate transient responses of a piezoelectric resonator. The envelopes and waveforms of current and vibration velocity in transient responses observed in some piezoelectric ceramics could be fitted with the calculation including nonlinear responses. The procedure for calculation of mechanical quality factor Qm for piezoelectric resonators with nonlinear behaviors was also proposed. View full abstract»

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  • Electromechanical coupling and temperature-dependent polarization reversal in piezoelectric ceramics

    Publication Year: 2011 , Page(s): 1730 - 1736
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    Electrostriction plays a central role in describing the electromechanical properties of ferroelectric materials, including widely used piezoelectric ceramics. The piezoelectric properties are closely related to the underlying electrostriction. Small-field piezoelectric properties can be described as electrostriction offset by the remanent polarization which characterizes the ferroelectric state. Indeed, even large-field piezoelectric effects are accurately accounted for by quadratic electrostriction. However, the electromechanical properties deviate from this simple electrostrictive description at electric fields near the coercive field. This is particularly important for actuator applications, for which very high electromechanical coupling can be obtained in this region. This paper presents the results of an experimental study of electromechanical coupling in piezoelectric ceramics at electric field strengths close to the coercive field, and the effects of temperature on electromechanical processes during polarization reversal. The roles of intrinsic ferroelectric strain coupling and extrinsic domain processes and their temperature dependence in determining the electromechanical response are discussed. View full abstract»

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  • Modeling and characterization of piezoelectrically actuated bistable composites

    Publication Year: 2011 , Page(s): 1737 - 1750
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    This paper develops and validates a finite-element model to predict both the cured shape and snap-through of asymmetric bistable laminates actuated by piezoelectric macro fiber composites attached to the laminate. To fully describe piezoelectric actuation, the three-dimensional compliance [sij], piezoelectric [dij], and relative permittivity [εij] matrices were formulated for the macro fiber actuator. The deflection of an actuated isotropic aluminum beam was then modeled and compared with experimental measurements to validate the data. The model was then extended to bistable laminates actuated using macro fiber composites. Model results were compared with experimental measurements of laminate profile (shape) and snap-through voltage. The modeling approach is an important intermediate step toward enabling design of shape-changing structures based on bistable laminates. View full abstract»

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  • Vibrational properties of the LiNbO3 z-surfaces

    Publication Year: 2011 , Page(s): 1751 - 1756
    Cited by:  Papers (1)
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    The existence of localized vibrational modes both at the positive and at the negative LiNbO3 (0001) surface is demonstrated by means of first-principles calculations and Raman spectroscopy measurements. First, the phonon modes of the crystal bulk and of the (0001) surface are calculated within the density functional theory. In a second step, the Raman spectra of LiNbO3 bulk and of the two surfaces are measured. The phonon modes localized at the two surfaces are found to be substantially different, and are also found to differ from the bulk modes. The calculated and measured frequencies are in agreement within the error of the method. Raman spectroscopy is shown to be sensitive to differences between bulk and surface and between positive and negative surface. It represents therefore an alternative method to determine the surface polarity, which does not exploit the pyroelectric or piezoelectric properties of the material. View full abstract»

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  • Ceramic piezocomposites: Modeling, technology, and characterization

    Publication Year: 2011 , Page(s): 1757 - 1773
    Cited by:  Papers (1)
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    A comprehensive review of microstructure peculiarities, mathematical models, methods of fabrication and measurements, as well as systematic experimental data for different types of ceramic piezocomposites is presented. New families of polymer-free ceramic piezocomposites (composites ceramics/ceramics and ceramics/crystals) with properties combining better parameters of PZT, PN type ceramics, and 1-3 composites are introduced. New damped-by-scattering ceramic piezocomposites, characterized by previously unachievable parameter combinations, are proposed. New material design concepts and fabrication methods for ceramic piezocomposites are considered. Piezoelectric resonance analysis methods for automatic iterative evaluation of complex material parameters, together with the sets of complex constants for different ceramic piezocomposites, are presented. Microstructural and physical mechanisms of losses and dispersion in ceramic piezocomposites, as well as technological aspects for their large-scale manufacture and application in ultrasonic devices are considered. View full abstract»

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  • Fabrication of PIMNT/Epoxy 1-3 composites and ultrasonic transducer for nondestructive evaluation

    Publication Year: 2011 , Page(s): 1774 - 1781
    Cited by:  Papers (1)
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    In this paper, PIMNT/epoxy 1-3 composites with different volume fractions were prepared by the dice-and-fill method for application in ultrasonic transducers. The theoretical and experimental properties at different volume fractions and the temperature stability of the electromechanical property were investigated. The highest electromechanical coupling factor kt was obtained as 0.833 with the volume fraction of 0.58 and kt changed little below the Curie temperature of the single crystal. Afterward, an angle-beam transverse wave ultrasonic transducer using the fabricated composite was designed and manufactured based on the simulation of the KLM model and commercial software. The assembled prototype transducer showed large improvement in two-way insertion loss, relative bandwidth at -6 dB, surplus sensitivity, and axial resolution, which were -24.3 dB, 107%, 85 dB, and 28 dB, respectively, compared with a commercial PZT-based composite transducer. View full abstract»

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  • Designing piezoelectric films for micro electromechanical systems

    Publication Year: 2011 , Page(s): 1782 - 1792
    Cited by:  Papers (2)
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    Piezoelectric thin films are of increasing interest in low-voltage micro electromechanical systems for sensing, actuation, and energy harvesting. They also serve as model systems to study fundamental behavior in piezoelectrics. Next-generation technologies such as ultrasound pill cameras, flexible ultrasound arrays, and energy harvesting systems for unattended wireless sensors will all benefit from improvements in the piezoelectric properties of the films. This paper describes tailoring the composition, microstructure, orientation of thin films, and substrate choice to optimize the response. It is shown that increases in the grain size of lead-based perovskite films from 75 to 300 nm results in 40 and 20% increases in the permittivity and piezoelectric coefficients, respectively. This is accompanied by an increase in the nonlinearity in the response. Band excitation piezoresponse force microscopy was used to interrogate the nonlinearity locally. It was found that chemical solution-derived PbZr0.52Ti0.48O3 thin films show clusters of larger nonlinear response embedded in a more weakly nonlinear matrix. The scale of the clusters significantly exceeds that of the grain size, suggesting that collective motion of many domain walls contributes to the observed Rayleigh behavior in these films. Finally, it is shown that it is possible to increase the energy-harvesting figure of merit through appropriate materials choice, strong imprint, and composite connectivity patterns. View full abstract»

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  • Characterization of piezocrystals for practical configurations with temperature- and pressure-dependent electrical impedance spectroscopy

    Publication Year: 2011 , Page(s): 1793 - 1803
    Cited by:  Papers (6)
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    Piezoelectric single crystal materials such as (x)Pb(Mg1/3Nb2/3)O3-(1-x)PbTiO3 (PMN-PT) have, by some measures, significantly better performance than established piezoelectric ceramics for ultrasound applications. However, they are also subject to phase transitions affecting their behavior at temperatures and pressures encountered in underwater sonar and actuator applications and in non-destructive testing at elevated temperatures. Materials with modified compositions to reduce these problems are now under development, but application-oriented characterization techniques need further attention. Characterization with temperature variation has been reported extensively, but the range of parameters measured is often limited and the effects of pressure variation have received almost no attention. Furthermore, variation in properties between samples is now rarely reported. The focus of this paper is an experimental system set up with commercially available equipment and software to carry out characterization of piezoelectric single crystals with variation in temperature, pressure, and electrical bias fields found in typical practical use. We illustrate its use with data from bulk thickness-mode PMN-29%PT samples, demonstrating variation among nominally identical samples and showing not only the commonly reported changes in permittivity with temperature for bulk material but also significant and complicated changes with pressure and bias field and additional ultrasonic modes which are attributed to material phase changes. The insight this provides may allow the transducer engineer to accelerate new material adoption in devices. View full abstract»

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  • Electric field-induced strain behavior in lithium- and copper-added potassium sodium niobate piezoceramics and 1-3 piezocomposites

    Publication Year: 2011 , Page(s): 1804 - 1810
    Cited by:  Papers (5)
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    Potassium sodium niobate (KNN)-based leadfree materials were prepared and their field-induced strain behaviors were investigated. Ceramic lead-free piezoelectric materials were prepared in bulk and fiber forms with 1 mol% CuO-added potassium sodium niobate K0.5Na0.5NbO3 and x = 7 mol% lithium-modified (K0.5-x/2 Na0.5-x/2Lix)NbO3 compositions. Fibers were drawn using a novel alginate gelation technique. Piezocomposites were prepared from these fibers with 1-3 connectivity and an epoxy matrix. A fully recoverable electrostrain of up to approximately 0.11% was observed in the CuO-added sample, whereas the Li-modified sample yielded up to 0.10% at 50 kV/cm electric field. A strain value of up to approximately 0.03% at 50 kV/cm electric field was obtained for piezocomposites prepared from lithium-modified fibers. The high-field converse piezoelectric coefficient was calculated from the strain-electric field (x-E) graph for all samples. Strain characteristics of the bulk and piezocomposite samples were analyzed based on the variation of strain with respect to square of the polarization (x-P2) to determine the electrostrictive contribution to the strain. View full abstract»

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  • Dielectric and piezoelectric properties in the lead-free system Na0.5K0.5NbO3-BiScO3-LiTaO3

    Publication Year: 2011 , Page(s): 1811 - 1818
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    Phase relations, dielectric and piezoelectric properties are reported for the ternary system 98%[(1 - x) (Na0.5K0.5NbO3)-x(LiTaO3)]-2%[BiScO3] for compositions x-10 mol% LiTaO3. The phase content at room-temperature changed from mixed phase, monoclinic + tetragonal, for unmodified 98%(Na0.5K0.5NbO3)-2%(BiScO3), to tetragonal phase for compositions >;2 mol% LiTaO3. Curie peaks at 360 to 370°C were observed for all compositions, but peaks became diffuse at x-3 mol%, and two dielectric peaks, at 370 and 470°C, were observed for 5 mol% LiTaO3. Phase segregation, and finite size affects associated with the core-shell structure, account for the occurrence of two dielectric peaks in 5 mol% LiTaO3, and diffuse dielectric behavior. The value of d33 piezoelectric charge coefficient increased from ~160 pC/N for 0 mol% LiTaO3 to 205 to 214 pC/N for 1 to 2 mol% LiTaO3 solid solutions, before falling sharply at 3 mol% LiTaO3. TEM-EDX analysis revealed core-shell grain structures with segregation of Bi, Sc, and Ta in the outer ~100-nm shell of the 5 mol% LT sample. View full abstract»

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  • Phase diagram and structure-property relationships in the lead-free piezoelectric system: Na0.5K0.5NbO3-LiTaO3

    Publication Year: 2011 , Page(s): 1819 - 1825
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    A phase-diagram for the Na0.5K0.5NbO3-LiTaO3 solid solution series (NKN-LT) is presented for compositions ≤10 mol% LT, based on the combined results of temperature-variable X-ray powder diffraction and dielectric measurements. In addition to the reported orthorhombic and tetragonal polymorphs of NKN-LT, a monoclinic phase is revealed. Changes to electrical properties as a function of LT substitution are correlated to phase content. Increasing the LT content from 5 to 7 mol% LT led to improved temperature stability of piezoelectric properties because of the avoidance of the monoclinic-tetragonal polymorphic phase transition during thermal cycling (at >;25°C). For 7 mol% LT samples: d33 = 200 pC/N; Tc = 440°C; εr = 550 and tan δ = 0.02 (at 20°C). Modification of this composition by solid solution with BiScO3 led to a decrease in d33 values. Transmission electron microscopy of a sample of 0.95[0.93 NKN-0.07LT]-0.05BiScO3 indicated a core-shell grain structure which led to temperature-stable dielectric properties. View full abstract»

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  • Correlation between the structure and the piezoelectric properties of lead-free (K,Na,Li)(Nb,Ta,Sb)O3 ceramics studied by XRD and Raman spectroscopy

    Publication Year: 2011 , Page(s): 1826 - 1834
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    This article reviews on the use of Raman spectroscopy for the study of (K,Na,Li)(Nb,Ta,Sb)O3 lead-free piezoceramics. Currently, this material appears to be one of the most interesting and promising alternatives to the well-known PZT piezoelectric materials. In this work, we prepare piezoceramics with different stoichiometries and study their structural, ferroelectric, and piezoelectric properties. By using both Raman spectroscopy and X-ray diffraction, we establish a direct correlation between the structure and the properties. The results demonstrate that the wavenumber of the A1g vibration is proportional to the tetragonality, the remnant polarization, and the piezoelectric coefficients of these materials. Thus, Raman spectroscopy appears as a very useful technique for a fast evaluation of the crystalline structure and the ferroelectric/ piezoelectric properties. View full abstract»

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  • Piezoelectric properties and unipolar fatigue behavior of KNN-based Pb-free piezoceramics

    Publication Year: 2011 , Page(s): 1835 - 1841
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    Single-phase perovskite ceramics were synthesized using a Pb-free (K0.44Na0.52Li0.04)(Nb0.86Ta0.10Sb0.04)O3 (LF4) piezoelectric material both with and without CuO as a dopant additive. Bipolar hysteresis measurements showed a relatively high remanent polarization (20 μC/cm2, 16 μC/ cm2) and maximum polarization (25 μC/cm2, 21 μC/cm2) values were found for undoped LF4 and 0.2 wt% CuO-doped LF4, respectively. Unipolar fatigue behavior for this system was found to decrease strongly with increased applied testing fields and increased test durations. For undoped LF4, the maximum polarization values were stable after 10 cycles after testing for 100,000 cycles duration. For the CuO-doped samples, increasing the testing field to 3EC resulted in twice the decrease in PMAX (-32%) compared with the 2EC tests at 106 cycles (-17%). At 2EC testing for CuO doping, polarization decreases continually through 107 cycles, with the decreases in PMAX and d33 both reaching a maximum (-22% and -30%, respectively) after 107 cycles. In the CuO-doped samples, the fatigue is exacerbated because of the influence of space charge on the increased number of defects present. View full abstract»

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  • Investigation of electrostrictive polymer efficiency for mechanical energy harvesting

    Publication Year: 2011 , Page(s): 1842 - 1851
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    The purpose of this paper is to propose new means for harvesting energy using electrostrictive polymers. Recent trends in energy conversion mechanisms have demonstrated the abilities of electrostrictive polymers for converting mechanical vibrations into electricity. In particular, such materials present advantageous features such as a high productivity, high flexibility, and ease of processing; hence, the application of these materials for energy harvesting purposes has been of significant interest over the last few years. This paper discusses the development of a model that is able to predict the energy harvesting capabilities of an electrostrictive polymer. Moreover, the energy scavenging abilities of an electrostrictive composite composed of terpolymer poly(vinylidenefluoridetrofluoroethylene- chlorofluoroethylene) [P(VDF-TrFE-CFE)] filled with 1 vol% carbon black (C) is evaluated. Experimental measurements of the harvested power and current have been compared with the theoretical behavior predicted by the proposed model. A good agreement was observed between the two sets of data, which consequently validated the proposed modeling to optimize the choice of materials. It was also shown that the incorporation of nanofillers in P(VDF-TrFE-CFE) increased the harvested power. View full abstract»

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  • Effect of material constants on power output in piezoelectric vibration-based generators

    Publication Year: 2011 , Page(s): 1852 - 1859
    Cited by:  Papers (2)
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    A possible power output estimation based on material constants in piezoelectric vibration-based generators is proposed. A modified equivalent circuit model of the generator was built and was validated by the measurement results in the generator fabricated using potassium sodium niobate-based and lead zirconate titanate (PZT) ceramics. Subsequently, generators with the same structure using other PZT-based and bismuth-layered structure ferroelectrics ceramics were fabricated and tested. The power outputs of these generators were expressed as a linear functions of the term composed of electromechanical coupling coefficients ksys2 and mechanical quality factors Q*m of the generator. The relationship between device constants (ksys2 and Q*m) and material constants (k312 and Qm) was clarified. Estimation of the power output using material constants is demonstrated and the appropriate piezoelectric material for the generator is suggested. View full abstract»

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  • Dielectric and piezoelectric properties of CeO2-added nonstoichiometric (Na0.5K0.5)0.97(Nb0.96Sb0.04)O3 ceramics for piezoelectric energy harvesting device applications

    Publication Year: 2011 , Page(s): 1860 - 1866
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    In this study, nonstoichiometric (Na0.5K0.5)0.97(Nb0.96Sb0.04)O3 ceramics were fabricated and their dielectric and piezoelectric properties were investigated according to the CeO2 addition. In this ceramic composition, CeO2 addition improved sinterability, electromechanical coupling factor kp, mechanical quality factor Qm, piezoelectric constant d33, and g33. At the sintering temperature of 1100°C, for the 0.2wt% CeO2 added specimen, the optimum values of density = 4.359 g/cm3, kp = 0.443, Qm = 588, εr = 444, d33 = 159 pC/N, and g33 = 35 × 10¿3 V·m/N, were obtained. A piezoelectric energy harvesting device using 0.2wt% CeO2- added lead-free (K0.5Na0.5)0.97(Nb0.96Sb0.04)O3 ceramics and a rectifying circuit for energy harvesting were fabricated and their electrical characteristics were investigated. Under an external vibration acceleration of 0.7g, when the mass, the frequency of vibration generator, and matching load resistance were 2.4 g, 70 Hz, and 721 Ω, respectively, output voltage and power of piezoelectric harvesting device indicated the optimum values of 24.6 mVrms and 0.839 μW, respectively - suitable for application as the electric power source of a ubiquitous sensor network (USN) sensor node. View full abstract»

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  • Polarization dynamics and non-equilibrium switching processes in ferroelectrics

    Publication Year: 2011 , Page(s): 1867 - 1873
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    Time- and temperature-dependent effects are critical for the operation of non-volatile memories based on ferroelectrics. In this paper, we assume a domain nucleation process of the polarization reversal and we discuss the polarization dynamics in the framework of a non-equilibrium statistical model. This approach yields analytical expressions which can be used to explain a wide range of time- and temperature-dependent effects in ferroelectrics. Domain wall velocity derived in this work is consistent with a domain wall creep behavior in ferroelectrics. In the limiting case of para-electric equilibrium, the model yields the well-known Curie law. We also present experimental P-E loops data obtained for soft ferroelectrics at various temperatures. The experimental coercive fields at various temperatures are well predicted by the coercive field formula derived in our theory. View full abstract»

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Aims & Scope

IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control focuses on the theory, design, and application on generation, transmission, and detection of bulk and surface mechanical waves.

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Editor-in-Chief
Steven Freear
s.freear@leeds.ac.uk