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Applications of Ferroelectric and Workshop on the Piezoresponse Force Microscopy (ISAF/PFM), 2013 IEEE International Symposium on the

Date 21-25 July 2013

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Displaying Results 1 - 25 of 93
  • Properties of Hf/Zr doped (Na1/2Bi1/2TiO3) relaxor-ferroelectric ceramics under bias electrical field

    Publication Year: 2013 , Page(s): 175 - 178
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    In this study, Hafnium or Zirconium doped grain oriented (Na1/2Bi1/2)TiO3 (NBT) ceramics with <;001> orientation were fabricated by Templated Grain Growth (TGG) method using anisotropically shaped SrTiO3 template particles. These molten salt synthesized SrTiO3 platelets were tape cast with calcined NBT powder, and sintered at 1200°C for 6 h. Texture fractions up to 70% have been obtained. Also, electromechanical properties of Hf4+ and Zr4+ doped NBT ceramics under electrical bias were studied. View full abstract»

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  • Simulation of the locally measured d33 of piezoelectric 1-3-composites

    Publication Year: 2013 , Page(s): 179 - 182
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (209 KB) |  | HTML iconHTML  

    The influence of the finite measuring spot diameter on the measured value of the mean longitudinal piezoelectric coefficient of 1-3-composites was investigated using the Finite-Element-Method (FEM) and a subsequent analysis. The results are compared with the real areic distribution of the local longitudinal piezoelectric coefficient and with an analytical approximation formula. View full abstract»

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  • Inverse scheme to identify the temperature dependence of electromechanical coupling factors for piezoceramics

    Publication Year: 2013 , Page(s): 183 - 186
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (173 KB) |  | HTML iconHTML  

    In this contribution, we exploit an Inverse scheme enabling the identification of temperature dependent material parameters of piezoceramic materials as well as their electromechanical coupling factors. This information is indispensable to predict the behavior of sensors and actuators incorporating such materials. Principally, the identification procedure is based on an iterative adjustment of finite element (FE) simulations to measurements. As the results for the piezoceramic materials PIC255 and PIC155 (both fabricated from PI Ceramic) reveal, several material parameters (e.g., electric permittivities) strongly rely on temperature. However, the electromechanical coupling factors for these materials remain nearly constant in the considered temperature range -35 °C to +130 °C. View full abstract»

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  • Microwave dielectric constant measurements of strontium titanate using five mixture equations

    Publication Year: 2013 , Page(s): 268 - 271
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (430 KB) |  | HTML iconHTML  

    The microwave dielectric constant of strontium titanate ceramic dispersed in the polyethylene matrix is studied by powder mixture equations in this article. The experimental dielectric constant values of the mixtures are compared to the theoretical curves of five published mixing rules. A new empirical mixture equation is proposed. The dielectric constant of pure strontium titanate is then estimated by these mixing laws from the dielectric constants of composites of various filler concentrations. The theoretical errors of estimations of various rules are derived and analyzed. The new empirical mixture equation has shown good accuracy for the dielectric constant measurement of strontium titanate. View full abstract»

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  • Tunability and sensitivity modification by poling on PZT film of frequency-tunable ultrasonic microsensors

    Publication Year: 2013 , Page(s): 352 - 355
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (433 KB) |  | HTML iconHTML  

    Piezoelectric diaphragm-type tunable ultrasonic microsensors have been investigated in their performance modification induced by poling on the piezoelectric/ferroelectric thin film on the sensor diaphragm. The tunable sensor has a tuning electrode besides a sensing electrode to tune the resonant frequency through converse-piezoelectric stress in the diaphragm. Tunability and sensitivity changes has been traced under voltage applications on the tuning and poling electrodes on sensors having flat and buckled diaphragms. The buckled-diaphragm sensors have shown anomalies that the sensitivity decreases at a high poling voltage region and sensitivity butterfly curve to the tuning voltage reverses upside down in the voltage range. The buckling deflection shape of the diaphragm has been profiled under the poling and tuning voltage applications, and the origin of the sensitivity anomalies have been concluded to be a buckling direction reversal in the sensing electrode part induced by the combination of the poling and tuning stress. View full abstract»

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  • Ultraviolet direct domain writing on 128° YX-cut LiNbO3: For SAW applications

    Publication Year: 2013 , Page(s): 272 - 274
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    Domain engineering 128° YX-cut lithium niobate crystals by ultraviolet direct-domain writing is reported. The evidence of the inverted domains were shown from both piezoresponse force microscopy and hydrofluoric acid etching. View full abstract»

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  • Efficient compensation of nonlinear transfer characteristics for piezoceramic actuators

    Publication Year: 2013 , Page(s): 171 - 174
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (242 KB) |  | HTML iconHTML  

    In order to compensate for hysteresis errors in tracking and manipulation tasks, models describing the piezoceramic actuator nonlinearities are required. These models have to meet the following two criteria: (i) Efficiency and (ii) a bidirectional description of hysteresis phenomena. Due to its flexibility and efficiency, the Preisach operator is a promising tool to model transfer behavior of ferroelectric actuators in forward direction. However, the model cannot be inverted analytically. The scope of this contribution is therefore to introduce a novel, efficient algorithm for the numerical inversion of the Preisach operator. The algorithm is characterized as well as applied to linearize the voltage-deflection hysteresis of trimorph bending actuators. It is shown that independent of the model discretization, a maximum sampling frequency of 6.5 kHz is allowed for the proposed numerical inversion scheme. As result of this fast inversion technique, the Preisach model becomes interesting for real-time hysteresis compensation tasks. It shows to be competitive to other hysteresis models which are directly invertible, such as the Prandtl-Ishlinskii hysteresis operator. View full abstract»

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  • 3D MEMS piezoelectric ultrasound transducer technology

    Publication Year: 2013 , Page(s): 231 - 235
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1755 KB) |  | HTML iconHTML  

    Here we present a high performance 3D MEMS ultrasound transducer technology called Clarinet™ based on a combination of micromachined dome-shaped piezoelectric resonators arranged in a flexible architecture. In a drastic departure from typical PMUT membranes, our high performance PZNT thin film is integrated into a 3D dome-shaped membrane as the transducer's building block. Three different types of ultrasound array are presented as an example of this flexible architecture in which the frequency response has been tailored by mixing these basic cells and modifying their dimensions by lithography. These demonstrate customizable performance capabilities such as an acoustic intensity up to 300 W/cm2, one-way insertion loss as low as -4.2 dB, and ultra wide-bandwidth suitable for both therapeutic and imaging applications. In addition, low electrical impedance, and a low operating voltage compatible with ordinary integrated circuitry are characteristics of all the designs. View full abstract»

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  • New human machine interface devices using a piezoelectric poly(L-lactic acid) film

    Publication Year: 2013 , Page(s): 236 - 239
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    Poly(lactic acid) (PLA) is a well-known, environmentally-friendly polymer. Piezoelectric poly(L-lactic acid) (PLLA), a type of chiral polymer, exhibits a high shear piezoelectric constant, is highly transparent, and is not pyroelectric. New human machine interface devices with intuitive control can be fabricated using piezoelectric PLLA as a deformation sensor. Specifically, for projected capacitive touch panels widely used in smartphone technology, the PLLA film as a pressure sensor with multiple electrodes allows pressure-sensitive functions to be added to the touch panel display. View full abstract»

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  • Nonlinear dielectric response of polymer system with coexisting ferroelectric and relaxor states

    Publication Year: 2013 , Page(s): 159 - 161
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4180 KB) |  | HTML iconHTML  

    We report dielectric investigations of poly(vinylidene fluoride-trifluoroetylene), P(VDF-TrFE) copolymer, irradiated with high-energy electrons. While the ferroelectric copolymer is transformed into a relaxor system at high irradiation doses, our investigations, particularly nonlinear dielectric experiments, clearly evidence that at lower doses ferroelectric and relaxor states coexist in the P(VDF-TrFE). Nonlinear dielectric response furthermore reveals the nature of the ferroelectric phase transition, which is confirmed by the polarization measurements. View full abstract»

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  • Electric field effects on piezoelectric and ferroelastic strain in Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 piezoceramics

    Publication Year: 2013 , Page(s): 84 - 86
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (757 KB) |  | HTML iconHTML  

    Rietveld analysis of synchrotron diffraction data is used to resolve the macroscopic strain response of tetragonal barium zirconate titanate-barium calcium titanate (BZT-BCT) piezoceramics and determine the underlying strain mechanisms. A lattice strain contribution and a ferroelastic switching contribution are identified and both contribute significantly to the macroscopic strain. A large electrically induced ferroelastic domain texture is observed that undergoes strong relaxation upon removal of the electric field. This suggests that under cyclic conditions each field application leads to a strong ferroelastic domain reorientation that is identified to be responsible for the good piezoelectric performance observed in this class of materials. Moreover, the significance of orientation dependent structural changes is identified, which is crucial to fully understand the macroscopic strain response. View full abstract»

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  • Niobium doped lead zirconate titanate thin films grown by chemical solution deposition

    Publication Year: 2013 , Page(s): 76 - 79
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    Niobium (Nb) doping is known to have a beneficial effect on many properties of lead zirconate titanate (PZT) ceramics. Substituting titanium (Ti) or zirconium (Zr) on a B-site, Nb ions form positive point defects that repel oxygen vacancies, even though they are compensated by negative lead (Pb) vacancies of half their concentration. As a consequence, PZT domains are known to move more easily. Nb doped ceramics excel in high piezoelectric coefficients dij and eij, and high permittivities. In this work, we investigated concentration gradient issues, dielectric, ferroelectric, and piezoelectric properties of Nb doped, {100}-textured PZT thin films. The {100}-texture could be maintained throughout the investigated compositional range. As it is known that sol-gel processing tends to form Zr/Ti gradients, it was of interest to know whether Nb forms gradients, and if yes, in which direction. We observed a behaviour similar to one of Zr, an enrichment away from where nucleation happens, thus the top part of the layer. The transverse piezoelectric coefficient e31,f was measured in the direct mode at zero electric field, and in the converse mode as a function of the electric field. The Nb doped films exhibited higher dielectric constants and higher break-down fields, but lower remnant polarizations because of enhanced backs-switching. As compared to “standard” sol-gel PZT films, they show an increased piezoelectric performance at high fields and improved reliability. View full abstract»

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  • Impact of domain depth on SAW generation by acoustic superlattice transducer in 128° YX-cut lithium niobate

    Publication Year: 2013 , Page(s): 344 - 346
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (394 KB) |  | HTML iconHTML  

    Surface acoustic wave (SAW) generation on 128° YX acoustic superlattice has been investigated by considering the finite-depth of the domain created by the UV direct-domain writing. We found that bound and localized SAW will be generated when the domain depth of the ASL structure, underlying the transducer, is smaller and bigger than the lattice period, respectively. Efficient bound SAW can be achieved, provided the domain depth is 30% of the lattice period. View full abstract»

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  • PLD elaboration of piezoelectric ZnO thin film for 540 MHz Al/ZnO/Pt bulk acoustic wave resonator

    Publication Year: 2013 , Page(s): 275 - 278
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (607 KB) |  | HTML iconHTML  

    The ZnO thin films in Al/ZnO/Pt/Ti/SiO2/Si Bulk Acoustic Wave (BAW) resonators are realized by a reactive Pulsed Laser Deposition (PLD) technique. It is of most interest to improve their piezoelectric characteristics. These later are intimately linked to the microstructure, the texture and the growth conditions. In this work, the piezoelectric characteristics of ZnO thin films have been investigated. Wurtzite ZnO thin films were prepared on Pt(111) at different substrate temperatures (100-500 °C). The 200 nm of Pt on 20 nm Ti were prepared by Electron Beam Deposition (EBD) technique at room temperature on 2 μm SiO2 substrate. This SiO2 film has been realized by Silicon wet thermal oxidation step at 1100 °C. The top electrode of the BAW was made by thermal evaporation of Aluminum; the piezoelectric film was confined in a circle of 1.8 mm radius. X-Ray Diffraction (XRD) characterization showed that the deposited Pt (bottom electrode) has (111) preferential orientation. It also showed that the ZnO films were c-axis (002) oriented. The Scanning Electron Microscopy (SEM) of the realized ZnO thin films showed evidence of compact grains with honeycomb-like structure on surface and evidence of columnar structure on cross-section. The measurements indicate that all substrate temperatures are suitable to obtain a good quality of ZnO, but Ts=300 °C is the optimum. In order to evaluate the piezoelectric properties of the BAW, measurements of the electrical input impedance and admittance have been performed. They showed evidence of piezoelectric response. The resonance frequency was obtained at 524.5 MHz and the anti-resonance frequency at 540.9 MHz. The electromechanical coupling coefficient Keff2 was evaluated to be 7.26 %, which is an indicator of a good piezoelectric response. From this measured values, the thickness d and the wave velocity Vp in the ZnO slab were de- uced to be respectively 6.15 μm and 6451.35 m/s and the piezoelectric constant e33 was found to be equal to 1.21 C/m2. View full abstract»

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  • Heat treatment effects on domain configuration and strain under electric field in undoped Pb[ZrxTi1−x]O3 ferroelectrics

    Publication Year: 2013 , Page(s): 149 - 151
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    Undoped Pb[ZrxTi1-x]O3 (PZT) ceramics from the tetragonal and rhombohedral side of the morphotropic phase boundary (MPB) were examined. Temperature dependent changes in domain configuration were observed by in situ hot-stage transmission electron microscopy (TEM). In corresponding macroscopic ex situ strain measurements an enhanced influence of the electric field was detected after annealing. View full abstract»

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  • Piezoceramic materials for high-temperature & high-pressure applications in oilfield exploration & production

    Publication Year: 2013 , Page(s): 62 - 65
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1693 KB) |  | HTML iconHTML  

    This work was originally motivated by the search for high-temperature piezoceramic materials with low acoustic impedance and high electromechanical coupling. The temperature and pressure behavior of two PZT-based materials with engineered porosity, Pz31 & Pz36 developed by Meggitt A/S, were studied. We considered operating environments of up to 200°C and 20,000 psi. Previous experimental results show that these two materials performed well at temperatures up to 175°C under normal pressure. However, both materials tend to depole by pressure cycling up to 15,000 psi. To develop insight into the depoling mechanism, we continued the study using the densified counterparts of these materials, Pz24 & Pz26 respectively. The experimental results clearly showed that the dense materials are not degraded under pressure. A bismuth titanate-based material, Pz46, with a high Curie temperature, was also investigated as part of this study to extend the operating temperature limit beyond 175°C. View full abstract»

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  • Large field property assessment of Mn:PIN-PMN-PT crystals for high power transducers

    Publication Year: 2013 , Page(s): 1 - 4
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    The third generation of advanced relaxor-PT piezoelectric single crystals, Mn:PIN-PMN-PT (manganese doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3), has attracted broad attention for high power transducer applications due to their greatly reduced mechanical loss but well-maintained, extremely high electromechanical coupling coefficient. Small signal characterization of Mn:PIN-PMN-PT crystals have been extensively studied. However, systematic large signal tests of Mn:PIN-PMN-PT crystals were urgently needed for further assessing the properties for high power transducer operation. In this work, systematic large signal, quasistatic measurements have been conducted for Mn:PIN-PMN-PT crystals under variable prestress, temperature and electric field. Preliminarily optimized operation domains for high power transducer design have been revealed for [001]-poled crystals for achieving maximum acoustic power density with low hysteretic losses caused by nonlinearity and phase transitions. View full abstract»

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  • A curled PZT cantilever based MEMS harvester

    Publication Year: 2013 , Page(s): 162 - 165
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (878 KB) |  | HTML iconHTML  

    A curled PZT cantilever based MEMS energy harvester using inter-digitally shaped electrodes was newly developed to generate high output voltage at a low resonance frequency from ambient vibrations. The curled piezoelectric cantilever was utilized to scavenge both vertical and longitudinal vibrations. It was comprised of polyimide, electrodes, PZT, and low stress silicon nitride layers and formed by using the intrinsic stress-induced bending deformation of a multi-layered cantilever. The inter-digitally shaped electrodes were employed for the d33 piezoelectric mode operation and high output voltage. The polyimide was utilized as an elastic layer to decrease the resonance frequency of the harvester to below 200 Hz. The fabricated MEMS energy harvester generated the output voltage of 0.5 V and 1.08 V at its resonance frequency of 114.7 Hz under vertically and longitudinally induced small vibrations with acceleration of 2.3 m/s2. View full abstract»

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  • Laser scanning microscopy observation of domain switching in NaNbO3 epitaxial film

    Publication Year: 2013 , Page(s): 13 - 16
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    Domain patterns of a 001-oriented NaNbO3 film prepared on a SrRuO3/(001)SrTiO3 (STO) substrate were observed by laser scanning microscopy during the application of the ac electric field amplitude of 100 kV/cm. The domain patterns consisted of vertical and horizontal stripes along the [100] and [010] directions of the (001) STO substrate and slanted stripes along the [110] and [1-10] directions. Only the slanted domain patterns changed with the electric field. When the electric field decreased from +100 kV/cm to -100 kV/cm, some slanted domain patterns shrank in the stripe direction and completely disappeared near the coercive field, and then reappeared and expanded in the stripe direction upon further decrease of the electric field while other domain patterns just shrank and expanded in the stripe direction without disappearance. These results suggested two kinds of domain switching route in the 001-oriented NaNbO3 thin film. View full abstract»

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  • (Ag,Li)NbO3 thin films fabricated on (001), (110), and (111)SrTiO3 substrates by pulsed laser deposition

    Publication Year: 2013 , Page(s): 127 - 129
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    001-, 110-, 111-oriented (Ag1-xLix)NbO3 (ALN) films with x=0.05 (ALN05), 0.1 (ALN10), and 0.15 (ALN15) were fabricated on (001), (110) and (111) SrTiO3 (STO) substrates by pulse laser deposition (PLD). The surface texture of the ALN films ware dependent on the crystal orientation of STO substrates. All the ALN films exhibited a ferroelectric behavior. The ALN films with x=0.1 deposited on (111) STO showed the largest remanent polarization of 40μC/cm2. View full abstract»

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  • High frequency magneto-impedance effects in (Co-Ti-O)/Bi-Ti-O multilayer films

    Publication Year: 2013 , Page(s): 56 - 58
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    (Co-Ti-O)/Bi-Ti-O multilayer films with 9 Co-Ti-O layers are prepared by tandem sputtering. The high frequency soft magnetic properties and magneto-impedance effects were investigated in the frequency range from 0.1 to 10 GHz. The films maintain the real part of permeability μ' = 30 up to a few GHz, and exhibit a clear peak of imaginary part of permeability μ" = 76.4 at the resonance frequency (fr). The μ" value at fr decreases with increasing an external magnetic field (Hex) applied parallel to the rf magnetic field. From the frequency response of the films, the admittance (Y) shows notable change near fr, which decrease with increasing Hex. View full abstract»

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  • Piezoelectric transducers on the basis of free-formed PZT components

    Publication Year: 2013 , Page(s): 279 - 282
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1007 KB) |  | HTML iconHTML  

    Structural devices with integrated adaptive functions are demanded in lightweight engineering especially in automotive and aerospace industries and mechanical engineering. As base of such systems, piezocomposites are of high interest. They can be made from piezoceramic components, e.g. plates, fibers, or more complex three-dimensional structures, integrated into matrix materials. We developed the polysulfone spinning process as an appropriate technique to produce dense piezoceramic components with different shapes. The paper reports on fabrication and properties of PZT fibers, fiber fragments and spherical samples (pearls). Potential applications of customized PZT components for smart structures and ultrasonic transducers are shown. View full abstract»

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  • A MEMS AlN transducer array for use as a cochlear implant

    Publication Year: 2013 , Page(s): 240 - 243
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (643 KB) |  | HTML iconHTML  

    A piezoelectric cantilever array was fabricated, for use as a cochlear implant. An array of 4.2μm thick aluminum nitride (AlN) bimorph cantilevers, laminated with platinum and mounted on a silicon backbone, are designed to transduce incident sound pressure waves into electrical current when submerged in ionic cochlear fluid. The ability to prescribe the desired geometry and to deposit high quality piezoelectric films are two key aspects crucial to the success of this design concept. A 3cm parylene - gold - parylene ribbon cable extends from the probe to an electrode bay, for external measurements of the transducer array response. The AlN film is measured to have a rocking curve of 0.94° full width half maximum (FWHM), a d31 of 2.1 pm/V, and a dissipation factor of 0.002. The actuated response of a single cantilever element in air shows good agreement with model predictions. View full abstract»

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  • Resistive hysteresis of MOD-made BaTiO3 ferroelectric thin film dependent on film thickness

    Publication Year: 2013 , Page(s): 187 - 189
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    An MOD-made BaTiO3 (BT) thin film was prepared for investigating the relation between its ferroelectric properties and the behavior of resultant resistive hysteresis. For ferroelectric 110 nm-thickness BT film, its coercive field is observed to relate quantitatively to the characteristics of resistive hysteresis, where the current on/off ratio is obtained as 1-2 orders of magnitude. We consider that the ferroelectricity in the film makes a different type of behavior in resistive hysteresis and is effective for improving the behavior and characteristics. View full abstract»

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  • Effects of Nb doping in lead barium zirconate ceramics

    Publication Year: 2013 , Page(s): 89 - 92
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (131 KB) |  | HTML iconHTML  

    The electromechanical properties of ferroelectric materials can be modified by doping in order to meet the requirements for various applications. This is well known in PZT ceramics, in which even a very small amount of the dopant element affects macroscopic properties and makes the ferroelectric hard or soft. We investigate whether hard and soft behavior occurs also due to doping of PBZ, which, to the best of our knowledge, has not been studied before. Pb0.77Ba0.23ZrO3 ceramics with 1-mol%-PbO-excess have been prepared with various Nb-dopant concentrations between 0.05 and 2 mol% by the mixed-oxide route. The densification behavior and the microstructural development, as well as ferroelectric, dielectric, and piezoelectric proper-ties were measured and analyzed. The phase analysis of the sintered solid solutions revealed sin-gle-phase perovskite for all concentrations. The results showed a different relative density and grain size dependence for samples containing >0.5 mol% additives compared to samples with <;0.5 mol% Nb. Nb doping influenced significantly the electrical characteristics. Softening and a very marked increase in the dielectric and piezoelectric characteristics were obtained for low con-centrations of Nb+5. The influence of the dopants and associated defects on the physical and electrical characteristics was investigated and well correlated. View full abstract»

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