# 14th IEEE International Symposium on Applications of Ferroelectrics, 2004. ISAF-04. 2004

## Filter Results

Displaying Results 1 - 25 of 95
• ### Analytical modeling of the variation in apparent d33 piezoelectric coefficient measured by the direct quasistatic method as a function of sample aspect ratio

Publication Year: 2004, Page(s):293 - 296
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In this study we present an analytical model in which apparent (measured) d33 is a function of the aspect ratio, the mechanical properties of the contacts and the properties of piezoelectric ceramics. Using derived relations it is possible to obtain the true value of d33 in the wide range of boundary conditions. The analytical results are compared with simulations using finit... View full abstract»

• ### Regarding the determination of the electromechanical coupling factor of a ferroelectric plate vibrating in thickness-shear mode

Publication Year: 2004, Page(s):289 - 292
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This paper deals with the determination of the electromechanical coupling factor k26 of selected rotated Y-cut quartz homeotype gallium orthophosphate (GaPO4) resonators, and k15 of a polarized ferroelectric PZT plate, vibrating in the thickness-shear mode. The IRE standards on piezoelectric crystals recommends the application of the dielectric method and determina... View full abstract»

• ### Piezoelectric anisotropy - phase transition relations in perovskite single crystals

Publication Year: 2004, Page(s):110 - 113
Cited by:  Papers (3)
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The orientation dependence of the longitudinal piezoelectric coefficient is investigated as a function of temperature in BaTiO3 and PbTiO3 crystals using Landau-Ginsburg-Devonshire theory. We show that a presence of the ferroelectric - ferroelectric phase transitions in BaTiO3 leads to an enhanced piezoelectric longitudinal response along nonpolar directions. The r... View full abstract»

• ### Design of a Si MMIC compatible ferroelectric varactor shunt switch for microwave applications

Publication Year: 2004, Page(s):285 - 288
Cited by:  Papers (1)  |  Patents (1)
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This paper describes a capacitive shunt switch, based on ferroelectric varactors as a potential replacement for RF MEMS switches for microwave applications. Our implementation is based on a coplanar waveguide (CPW) transmission line shunted by a ferroelectric varactor. The novelty in the implementation comes from the elimination of any moving parts (as in MEMS switches) for switching. The concept ... View full abstract»

• ### FEM modeling of electro-elastic field in ferroelectric crystal with domain boundaries

Publication Year: 2004, Page(s):106 - 109
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The parameters of ferroelectric thin layers are closely related to properties of materials from which they are made. Electric and elastic fields have large influence on important properties of discussed materials. The paper describes an application of the finite element method in modelling of electric and elastic fields in ferroelectric crystals and their influence on the shifts of domain boundari... View full abstract»

• ### An investigation of BST:MgTiO3 and X7R:MgTiO3 based ceramics for microwave applications

Publication Year: 2004, Page(s):281 - 284
Cited by:  Papers (1)
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There is a growing demand for dielectrics with field tunable permittivity for use in frequency agile filters and phase shifters at microwave frequencies. The paraelectric phase composition of barium strontium titan a to (BST) is a popular choice because of its non-linear properties demonstrated by the field dependence of permittivity. However, the dielectric properties of BST compositions are temp... View full abstract»

• ### The direct piezoelectric effect in [001]C-poled relaxor-ferroelectric single crystals: contrasting longitudinal and transverse modes

Publication Year: 2004, Page(s):102 - 105
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Direct measurements of longitudinal (d33) and transverse (d31) coefficients have been made on single crystal 0.68Pb(Mg13/Nb23/)O3-0.32PbTiO3 (PMN-32PT) and 0.955Pb(Zn13/Nb23/)O3-0.045PbTiO3 (PZN-4.5PT), poled along the [001]C direction (C: pseudocubic). The measurements were mad... View full abstract»

• ### Harmonic analysis of the polarization hysteresis loops for aged PZT

Publication Year: 2004, Page(s):213 - 216
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Lead zirconate titanate (PZT) suffers aging, which cause its properties to deteriorate. Understanding the aging of PZT is critical to the design of devices. This work used harmonic analysis to study polarization hysteresis loops (PE-loop) of aged PZT. The results indicated that harmonics 1-5 have unique effect on the shape of PE-loops. The changing of these amplitudes and phase angles of these har... View full abstract»

• ### Optimization of high tunability barium strontium titanate thin films grown by RF magnetron sputtering

Publication Year: 2004, Page(s):278 - 280
Cited by:  Papers (3)
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Barium strontium titanate is a solid solution perovskite with a field-dependent permittivity. At microwave frequencies, its tunable dielectric constant and low loss make it a competitive choice for varactors and other tunable circuit elements. Much attention has been focused on the production of low-loss films for such applications, with little emphasis on how the film properties contribute to the... View full abstract»

• ### A highly tunable radio frequency filter using bulk ferroelectric materials

Publication Year: 2004, Page(s):25 - 28
Cited by:  Papers (3)
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The desirable attribute of software defined radios (SDR) implies that RF Front-ends must be multi-band and frequency agile. Wideband SDRs need a lower size, weight, and power (SWAP) tunable filter technology to meet the military's current and future communications needs. This is essential for the SDR operating in a battery powered environment such as man-portable Joint Tactical Radios (JTRS). The ... View full abstract»

• ### Conversion of 45° rotated X-cut KNbO3 plates to Y-cut plates by compression

Publication Year: 2004, Page(s):98 - 101
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Potassium niobate (KNbO3) single crystals with a pseudo-cubic structure exhibit very high piezoelectric coupling factors for thickness-extensional modes and surface acoustic waves, kt and kSAW. To obtain a better understanding of domain-behavior with a stress, conversion of high-kt 45° rotated X-cut plates of KNbO3 to high-kSAW ... View full abstract»

• ### Phenomenological and structural studies of the morphotropic phase boundary in lead zinc niobate (PZN)-lead titanate (PT)

Publication Year: 2004, Page(s):209 - 212
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Unknown dielectric stiffness coefficients in the elastic Gibbs free energy for Pb(Zn13/Nb23/)O3-PbTiO3 (PZN-PT) binary solid solution with monoclinic phase were estimated by fitting the calculated phase diagram with the available experimental one. The connecting coefficients of polarization of tetragonal and rhombohedral in a spontaneous polarization wer... View full abstract»

• ### Numerical model of influence of external electric loading on electro-elastic field in ferroelectrics

Publication Year: 2004, Page(s):313 - 315
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A mathematical modeling of behavior of possible proposed ferroelectric structures exposed various external loading can usefully support the design of real ferroelectric devices. The paper presents our numerical model of ferroelectric crystal specimen. The proposed model considers a ferroelectric crystal with an internal domain structure. The model is based on physical description that includes lin... View full abstract»

• ### Solid state grain growth of piezoelectric single crystals

Publication Year: 2004, Page(s):153 - 156
Cited by:  Papers (1)
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The recent results related to development of the solid state crystal growth process, specially focusing on PMN-PT are presented. The processing parameters such as sintering atmosphere and growth temperature of crystal are discussed. The feasibility of using SSCG for the growth of high Tc piezoelectric materials such as BiScO3-PbTiO3 will be also presented. The hete... View full abstract»

• ### Paraelectric (Ba0.6Sr0.4)TiO3 thick films by direct-write

Publication Year: 2004, Page(s):21 - 24
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MicroPen™ direct-write technique has been used to fabricate polycrystalline paraelectric BST 60/40 11-140 μm thick films on alumina substrates. The dielectric properties of the thick films were studied as a function of film thickness, microstructure, and the state of residual stresses. Sin2Ψ X-ray analyses indicated a compressive state of stress in the films which decreased... View full abstract»

• ### Direct-write of PZT thick films

Publication Year: 2004, Page(s):250 - 253
Cited by:  Papers (1)
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Lead zirconate titanate (PZT) thick films have been prepared on alumina substrates using a direct-write technology. Thick films of 50 to 200 μm were deposited, dried and then sintered at 1000° to 1200°C for 30 minutes in PbO-rich atmosphere. Comparison of the thick film properties revealed that the dielectric constant and remnant polarization of the films sintered at 1100°C were max... View full abstract»

• ### Dielectric nonlinearity of (100) oriented PYbN-PT thin films

Publication Year: 2004, Page(s):95 - 97
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The extrinsic contributions to the dielectric response of 0.5Pb(Yb12/Nb12/)O3-0.5PbTiO3 thin films with (100) crystallographic orientation were studied (all indices are given in terms of the pseudocubic cell). At 30 kV/cm, the irreversible contribution in the (100) oriented PYbN-PT films supplies 34% of the total dielectric response of the film. The diel... View full abstract»

• ### Pyroelectric properties and orthorhombic to rhombohedral electric field induced phase transition in relaxor-ferroelectric single crystals

Publication Year: 2004, Page(s):205 - 208
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The pyroelectric coefficients of 0.72Pb(Mg13/Nb23/)O3-0.28PbTiO3 (PMN-28PT), 0.67Pb(Mg13/Nb23/)O3-0.33PbTiO3 (PMN-33PT) and 0.92Pb(Zn13/Nb23/)O3-0.08PbTiO3 (PZN-8PT) single crystals, oriented and poled along the [001]c, [101]c and [111]c View full abstract»

• ### Size effect of barium titanate based ceramics sintered in reducing atmospheres

Publication Year: 2004, Page(s):324 - 327
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Non-reducible BT-based X7R type ceramic materials with grain size form 100 nm to 400 nm were prepared systematically with high performance using nano-sized BaTiO3 powders. The initial grain size of BT powders affects significantly the microstructure and dielectric properties. The dielectric constant could be enhanced by increasing the initial particle size. Using BT powder with size of ... View full abstract»

• ### In-situ domain observation of Pb(Mg13/Nb23/)O3-PbTiO3 single crystals near the Curie temperature using contact-resonance piezoresponse force microscope

Publication Year: 2004, Page(s):309 - 312
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The domain structure images of [001] plate of Pb(Mg13/Nb23/)O3-PbTiO3 (PMN-PT) single crystals were successfully obtained in a vacuum using contact resonance piezoresponse force microscope (CR-PFM). Although the Curie temperature of the sample was approximately 150°C, the same fingerprint-shaped domain images were observed up to 165°C. It was als... View full abstract»

• ### Structure and properties of high dielectric constant CaCu3Ti4O12 ceramics

Publication Year: 2004, Page(s):149 - 152
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The structure and dielectric properties of CaCu3Ti4O12 ceramics have been investigated. The starting CaCu3Ti4O12 powders were synthesized by a modified glycine nitrate process. The ceramics obtained exhibit a cubic perovskite structure. Dielectric constant up to 57,200 and dielectric loss of 4.4% at 1 kHz have been observed at room ... View full abstract»

• ### High temperature electrostrictive ceramics for a Venus ultrasonic rock sampling tool

Publication Year: 2004, Page(s):130 - 133
Cited by:  Papers (1)
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NASA's intended mission to Venus (the Venus In-situ Explorer) will require unprecedented advances in robotic technology suited for high temperatures and extreme environments. This paper addresses development of an ultrasonic rock drilling-coring-abrading tool to quickly sample Venus surface material for chemical analysis. The key innovation behind this device is a BiScO3-PbTiO3 View full abstract»

• ### Templated grain growth (TGG) of PMN-PT textured components using SrTiO3 templates

Publication Year: 2004, Page(s):270 - 273
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Tapes of PMN-PT containing 5 to 10 volume % of SrTiO3 seeds were cast and subjected to heat treatments of 1250°C in either air or oxygen atmospheres for 10 hours in order to texture the samples and enhance the (h00) peaks of PMN-PT. Lead-based additives such as lead oxide (PbO) and lead carbonate (PbCO3) were introduced to create a liquid phase during heat treatment of th... View full abstract»

• ### Low-loss, tunable microwave capacitors using bismuth zinc niobate thin films

Publication Year: 2004, Page(s):17 - 20
Cited by:  Papers (2)  |  Patents (1)
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A new high dielectric constant material, bismuth zinc niobate that combines low dielectric losses with an electric-field dependent permittivity was implemented as the dielectric in MIM capacitors. Dielectric properties up to 20 GHz were evaluated by measuring the reflection coefficient with a vector network analyzer. The dielectric constant was around 180 and the quality factor remained greater th... View full abstract»