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1

Determination of temperature dependence of piezoelectric coefficients matrix of lead zirconate titanate ceramics by quasi-static and resonance method  

NASA Astrophysics Data System (ADS)

The piezoelectric coefficients (d33, -d31, d15, g33, -g31, g15) of soft and hard lead zirconate titanate ceramics were measured by the quasi-static and resonance methods, at temperatures from 20 to 300 °C. The results showed that the piezoelectric coefficients d33, -d31 and d15 obtained by these two methods increased with increasing temperature for both hard and soft PZT ceramics, while the piezoelectric coefficients g33, -g31 and g15 decreased with increasing temperature for both hard and soft PZT ceramics. In this paper, the observed results were also discussed in terms of intrinsic and extrinsic contributions to piezoelectric response.

Li, Fei; Xu, Zhuo; Wei, Xiaoyong; Yao, Xi

2009-05-01

2

Large Piezoelectric Constant and High Curie Temperature of Lead-Free Piezoelectric Ceramic Ternary System Based on Bismuth Sodium Titanate-Bismuth Potassium Titanate-Barium Titanate near the Morphotropic Phase Boundary  

Microsoft Academic Search

A lead-free piezoelectric ceramic ternary system based on bismuth sodium titanate, (Bi1\\/2Na1\\/2)TiO3 (BNT) - bismuth potassium titanate (Bi1\\/2K1\\/2)TiO3 (BKT) - barium titanate BaTiO3 (BT) near the morphotropic phase boundary (MPB) between the tetragonal and rhombohedral phases has been investigated. In the case of a(Bi1\\/2Na1\\/2)TiO3-bBaTiO3-c(Bi1\\/2K1\\/2)TiO3 [BNBK(100a\\/100b\\/100c)] solid solution ceramics, the highest piezoelectric constant d33=191 pC\\/N, Curie temperature, Tc=301°C, electromechanical coupling factor,

Hajime Nagata; Masaki Yoshida; Yoichi Makiuchi; Tadashi Takenaka

2003-01-01

3

Novel lead-free piezoelectric ceramics in the solid solution (1-x) bismuth iron oxide-barium titanate  

NASA Astrophysics Data System (ADS)

Piezoelectric materials are widely used in many areas of science and technology due to their electromechanical properties. The transformation of mechanical energy into electrical signals and vice versa based on the piezoelectric effect has led to the development of sensor devices and piezoelectric actuators used in accelerometers, pressure and vibration meters, micropositioning devices, ultrasound generators, motors etc. The most technologically important piezoelectric material is lead zirconate titanate PbZrO3-PbTiO3 (PZT), however, the commercial manufacture and application of PZT as a lead-based material represent serious health hazards. The need to reduce environmental contamination by lead-based substances has created the current drive to develop alternative lead-free piezoelectric materials. The present work describes a detailed investigation of the novel multifunctional ceramic material in a solid solution of bismuth iron oxide and barium titanate (1-x)BiFeO 3-xBaTiO3 (BFBT) with an emphasis on the room temperature piezoelectric properties and structural study. BFBT ceramics were prepared via the metal oxide solid-state preparation route. Addition of manganese oxide MnO2 increased the DC resistance by one to five orders of magnitude allowing high-field poling and piezoelectric strain measurements in Mn-modified BFBT ceramics. Piezoelectric d33 coefficients of 116 pC/N (low-field, Berlincourt) and 326 pC/N (effective, high-field) are reported for the compositions with x=0.25 and 0.33 respectively. Piezoelectric measurements using the Rayleigh law under applied large DC electric field indicated an increased low-field piezoelectric d33 coefficient to 150 pC/N (x=0.33). The DC bias is believed to stabilize the ferroclectric domain structure leading to stronger intrinsic and extrinsic contributions to the piezoelectric response in BFBT. Bright field TEM imaging confirmed formation of macroscopic domains following high field poling from initially frustrated domain state indicating the ability to induce long-range polarization order in BFBT ceramics. It is believed that the results of this work will contribute to the development of a family of lead-free piezoelectric materials based on BiFeO3-BaTiO3 system. KEYWORDS: Bismuth ferrite, Barium titanate, Lead-free, Piezoelectric ceramics, Crystal Structure

Leontsev, Serhiy

4

A piezoelectric plethysmograph sensor based on a Pt wire implanted lead lanthanum zirconate titanate bulk ceramic.  

PubMed

This work reports on the development of a Lead Lanthanum Zirconate Titanate (PLZT) bulk ferroelectric poled ceramic structure as a Piezoelectric Plethysmograph (PZPG) sensor. The ceramic was implanted during its fabrication with a platinum (Pt) wire which works as an internal electrode. The ceramic was then submitted to an experimental setup in order to validate and determine the Pt-wire mechanical effects. This PZPG sensor was also mounted on a finger splint in order to measure the blood flow that results from the pulsations of blood occurring with each heartbeat. Fingertip pulses were recorded jointly with an ECG signal from a 25 year old male to compare the time shift; the PZPG sensor guarantees the electrical isolation of the patient. The proposed PZPG has several advantages: it can be adjusted for fingertip measurements, but it can easily be extended by means of spare bands, therefore making possible PZPG measurements from different body locations, e.g., forehead, forearm, knee, neck, etc. PMID:22163596

González-Morán, Carlos O; Flores-Cuautle, J J Agustín; Suaste-Gómez, Ernesto

2010-01-01

5

A Piezoelectric Plethysmograph Sensor Based on a Pt Wire Implanted Lead Lanthanum Zirconate Titanate Bulk Ceramic  

PubMed Central

This work reports on the development of a Lead Lanthanum Zirconate Titanate (PLZT) bulk ferroelectric poled ceramic structure as a Piezoelectric Plethysmograph (PZPG) sensor. The ceramic was implanted during its fabrication with a platinum (Pt) wire which works as an internal electrode. The ceramic was then submitted to an experimental setup in order to validate and determine the Pt-wire mechanical effects. This PZPG sensor was also mounted on a finger splint in order to measure the blood flow that results from the pulsations of blood occurring with each heartbeat. Fingertip pulses were recorded jointly with an ECG signal from a 25 year old male to compare the time shift; the PZPG sensor guarantees the electrical isolation of the patient. The proposed PZPG has several advantages: it can be adjusted for fingertip measurements, but it can easily be extended by means of spare bands, therefore making possible PZPG measurements from different body locations, e.g., forehead, forearm, knee, neck, etc. PMID:22163596

González-Morán, Carlos O.; Flores-Cuautle, J.J. Agustín; Suaste-Gómez, Ernesto

2010-01-01

6

Elastic constants measured from acoustic wave velocities in barium titanate piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

The longitudinal and transverse wave velocities in barium titanate (BT) ceramics sintered at different firing temperatures were measured using an ultrasonic precision thickness gauge with high-frequency pulse generation to evaluate elastic constants, such as Young’s modulus and Poisson’s ratio. With increasing firing temperature, the longitudinal and transverse wave velocities increased; as a result, Young’s modulus increased because of BT ceramics being mechanically hard. Poisson’s ratio after DC poling, however, was almost independent of the firing temperature. It was confirmed that there was an important factor for generating piezoelectricity regarding changes in Young’s modulus and Poisson’s ratio after DC poling compared with those before DC poling, that is, lowering Young’s modulus and increasing Poisson’s ratio. Furthermore, the modulus of rigidity and bulk modulus increased with the firing temperature because of the increase in ceramic bulk density. The modulus of rigidity decreased and the bulk modulus increased during DC poling because of domain alignment.

Ogawa, Toshio; Ikegaya, Taiki

2015-01-01

7

Uniaxial stress dependence of the piezoelectric properties of lead zirconate titanate ceramics  

Microsoft Academic Search

Piezoelectric ceramics are often used under compressive stress. We have measured the dynamic value of the piezoelectric charge coefficient, d33, as a function of uniaxial stress in the poled direction. Results on two types of PZT ceramics manufactured by EDO Corporation are presented; in general, they show a nonlinear behaviour with an initial increase in d33 as the stress increases

G. Yang; S.-F. Liu; W. Ren; B. K. Mukherjee

2000-01-01

8

Effects of porosity on dielectric and piezoelectric properties of porous lead zirconate titanate ceramics  

NASA Astrophysics Data System (ADS)

We report porous lead zirconate titanate ceramics fabricated by tert-butyl alcohol-based gel-casting process which show a very high thickness electromechanical coupling coefficient (0.77), high hydrostatic figure of merit (9594×10-15 m2/N), and low acoustic impedance (3.7 Mrayls). We show that the porosity effectively affects the performance of the samples in two ways: (1) a higher porosity simplifies the resonance behavior, leading to more efficient energy transduction; (2) its replacement of active ceramic phase leads to low relative permittivity, high hydrostatic figure of merit, and low acoustic impedance. It was confirmed the properties could be tailored by controlling the porosity.

Yang, An-Kun; Wang, Chang-An; Guo, Rui; Huang, Yong

2011-04-01

9

Lead zirconate titanate ceramics  

SciTech Connect

This patent describes a lead zirconate titanate (PZT) piezoelectric ceramic composition which, based on total composition weight, consists essentially of a solid solution of lead zirconate and lead titanate in a PbZrO/sub 3/:PbTiO/sub 3/ ratio from about 0.505:0.495 to about 0.54:0.46; a halide salt selected from the group consisting of fluorides and chlorides of alkali metal and alkaline earth elements and mixtures thereof except for francium and radium in an amount from about 0.5 to 2 weight percent; and an oxide selected from the group consisting of magnesium, barium, scandium, aluminum, lanthanum, praesodynium, neodymium, samarium, and mixtures thereof in an amount from about 0.5 to about 6 weight percent, the relative amount of oxide being from about 1 to about 4 times that of the halide.

Walker, B.E. Jr.

1986-12-02

10

Enhanced piezoelectric properties of lead zirconate titanate (PZT) sol-gel derived ceramics using single crystal PZT cubes  

NASA Astrophysics Data System (ADS)

Piezoceramic materials have attracted much attention for sensing, actuation, structural health monitoring and energy harvesting applications in the past two decades due to their excellent coupling between energy in the mechanical and electrical domains. Among all piezoceramic materials, lead zirconate titanate (PZT) has been the most broadly studied and implemented, in industrial applications due to its high piezoelectric coupling coefficients. Piezoceramic materials are most often employed as thin films or monolithic wafers. While there are numerous methods for the synthesis of PZT films, the sol-gel processing technique is the most widely used due to its low densification temperature, the ease at which the film can be applied without costly physical deposition equipment and the capability to fabricate both thin and thick films. However, the piezoelectric properties of PZT sol-gel derived films are substantially lower than those of bulk materials, which limit the application of sol-gel films. In comparison, single crystal PZT materials have higher piezoelectric coupling coefficients than polycrystalline materials due to their uniform dipole alignment. This paper will introduce a novel technique to enhance the piezoelectric properties of PZT sol-gel derived ceramics through the use of single crystal PbZr0.52Ti0.48O3 microcubes as an inclusion in the PZT sol-gel. The PZT single crystal cubes are synthesized through a hydrothermal based method and their geometry and crystal structure is characterized through scanning electron microscopy (SEM) and X-ray diffraction (XRD). A mixture of PZT cubes and sol-gel will then be sintered to crystallize the sol-gel and obtain full density of the ceramic. XRD and SEM analysis of the cross section of the final ceramics will be performed and compared to show the crystal structure and microstructure of the samples. The P-E properties of the samples will be tested using a Sawyer-Tower circuit. Finally, a laser interferometer will be used to directly measure the piezoelectric strain-coupling coefficient of the PZT sol-gel ceramics with and without PZT cube inclusions. The results will show that with the integration of PZ0.52T0.48 crystal inclusions the d33 coupling coefficient will increase more than 200% compared to that of pure PbZr0.52Ti0.48O3 sol-gel.

Lin, Yirong; Andrews, Clark; Sodano, Henry A.

2010-04-01

11

Fabrication of piezoelectric ceramic\\/polymer composites by injection molding  

Microsoft Academic Search

Ceramic injection molding has been shown to be a viable process for fabricating both PZT (lead zirconate titanate) ceramics and piezoelectric ceramic\\/polymer transducers. The electrical properties of injection-molded PZT ceramics are comparable with those of ceramics prepared by conventional powder pressing, with no evidence of deleterious effects from metallic contamination and molding equipment. By using ceramic injection molding to fabricate

Leslie J. Bowen; Kenneth W. French

1992-01-01

12

Compact pulse forming line using barium titanate ceramic material  

Microsoft Academic Search

Ceramic material has very high relative permittivity, so compact pulse forming line can be made using these materials. Barium titanate (BaTiO3) has a relative permittivity of 1200 so it is used for making compact pulse forming line (PFL). Barium titanate also has piezoelectric effects so it cracks during high voltages discharges due to stresses developed in it. Barium titanate is

Surender Kumar Sharma; P. Deb; R. Shukla; T. Prabaharan; A. Shyam

2011-01-01

13

Piezoelectric Ceramics and Their Applications  

ERIC Educational Resources Information Center

Describes the piezoelectric effect in ceramics and presents a quantitative representation of this effect. Explains the processes involved in the manufacture of piezoelectric ceramics, the materials used, and the situations in which they are applied. (GS)

Flinn, I.

1975-01-01

14

Porous Piezoelectric Ceramic Transducer  

Microsoft Academic Search

Porous piezoelectric ceramics of Pb(Zr, Ti)O3, (P-PZT), have been newly developed to apply to transducers in an echo sounder. The P-PZT was prepared from a mixture of PZT and poly-methyl-methacrylate (PMMA) powders. The piezoelectric characteristics of the P-PZT such as the dielectric constant (?), voltage output constant (g constant), acoustic impedance (Zc) and Q were evaluated. The P-PZT was employed

Koichi Mizumura; Yoshiaki Kurihara; Hiroshi Ohashi; Susumu Kumamoto; Kiyonori Okuno

1991-01-01

15

Preparation of [110] Grain Oriented Barium Titanate Ceramics by Templated Grain Growth Method and Their Piezoelectric Properties  

Microsoft Academic Search

[110]-oriented barium titanate (BaTiO3) ceramics were prepared by templated grain growth (TGG) method using [110]-oriented BaTiO3 platelike particles as a template and hydrothermal BaTiO3 sphere particles with different particle sizes as a matrix. The degree of orientation along the [110] direction, F110, was measured using an X-ray diffraction (XRD) pattern by the Lotgering method. To obtain both a high density

Satoshi Wada; Kotaro Takeda; Tomomitsu Muraishi; Hirofumi Kakemoto; Takaaki Tsurumi; Toshio Kimura

2007-01-01

16

Enhanced piezoelectric properties of lead zirconate titanate sol-gel derived ceramics using single crystal PbZr0.52Ti0.48O3 cubes  

NASA Astrophysics Data System (ADS)

Piezoceramic materials have attracted much attention for sensing, actuation, structural health monitoring, and energy harvesting applications in the past two decades due to their excellent coupling between energy in the mechanical and electrical domains. Among all piezoceramic materials, lead zirconate titanate (PZT) has been the most broadly studied and implemented, in industrial applications due to its high piezoelectric coupling coefficients. Piezoceramic materials are most often employed as thin films or monolithic wafers. While there are numerous methods for the synthesis of PZT films, the sol-gel processing technique is the most widely used due to its low densification temperature, the ease at which the film can be applied without costly physical deposition equipment and the capability to fabricate both thin and thick films. However, the piezoelectric properties of PZT sol-gel derived films are substantially lower than those of bulk materials, which limit the application of sol-gel films. In comparison, single crystal PZT materials have higher piezoelectric coupling coefficients than polycrystalline materials due to their uniform dipole alignment. This paper will introduce a novel technique to enhance the piezoelectric properties of PZT sol-gel derived ceramics through the use of single crystal PbZr0.52Ti0.48O3 microcubes as an inclusion in the PZT sol-gel. The PZT single crystal cubes are synthesized through a hydrothermal based method and their geometry and crystal structure is characterized through scanning electron microscopy (SEM) and x-ray diffraction (XRD). A mixture of PZT cubes and sol-gel will then be sintered to crystallize the sol-gel and obtain full density of the ceramic. XRD and SEM analysis of the cross section of the final ceramics will be performed and compared to show the crystal structure and microstructure of the samples. The P-E properties of the samples will be tested using a Sawyer-Tower circuit. Finally, a laser interferometer will be used to directly measure the piezoelectric strain-coupling coefficient of the PZT sol-gel ceramics with and without PZT cube inclusions. The results will show that with the integration of PZT crystal inclusions the d33 coupling coefficient will increase more than 200% compared to that of pure PbZr0.52Ti0.48O3 sol-gel.

Lin, Yirong; Andrews, Clark; Sodano, Henry A.

2010-09-01

17

Promotion of osteogenesis by a piezoelectric biological ceramic.  

PubMed

Hydroxyapatite (HA) ceramic and piezoelectric biological ceramic, hydroxyapatite and barium titanate (HABT), were implanted in the jawbones of dogs. Histological observation showed that, compared with HA ceramics, HABT promoted the growth and repair of the bone significantly, the tissue growth around the HABT ceramic was direction-dependent, the collagen arranged orderly and the bone grew orderly. The order growth of the bone increased the efficiency of osteogenesis on the surface of the implanted HABT ceramics. PMID:9430335

Feng, J; Yuan, H; Zhang, X

1997-12-01

18

Piezoelectric properties of PLZT ceramics at different remanent polarization levels  

Microsoft Academic Search

The piezoelectric, electromechanical, and dielectric properties of lead lanthanum zirconate titanate (PLZT) ceramics at different remanent polarization levels were studied for acoustic imaging applications. The remanent polarizations at different levels were achieved by applying electric switching pulses with different widths. The piezoelectric coefficient obtained by direct and converse effects decreased with the remanent polarization, but the relations were not linear.

H. Wang; R. E. Newnham; L. E. Cross; W. Y. Pan

1990-01-01

19

Electromechanical Properties of A-Site (LiHo)Modified Strontium Bismuth Titanate (SrBi4Ti4O15) Piezoelectric Ceramics  

Microsoft Academic Search

The Aurivillius-type bismuth layer-structure Sr0.84(LiHo)0.08Bi4Ti4O15 (SBT-LiHo) piezoelectric ceramics were synthesized using conventional solid state processing. Phase analysis was performed by X-ray diffraction (XRD). The dielectric, piezoelectric, ferroelectric, and electromechanical properties of SBT-LiHo ceramics were investigated. The piezoelectric activities were found to be significantly enhanced compared to SrBi4Ti4O15 (SBT) ceramics, which can be attributed to the lattice distortion and the presence

B. Mamatha; A. R. James; P. Sarah

2011-01-01

20

New method for fabrication of lead-free BaTiO3 piezoelectric ceramics  

Microsoft Academic Search

BaTiO3 (BT) powders were synthesized by hydrothermal method for fabricating lead-free barium titanate piezoelectric ceramics. The effect of the two washing methods (distilled water and acetic acid solutions) on the piezoelectric properties of the BT ceramics was studied. BT ceramics with the higher piezoelectric properties (d33 value is over 190 pC\\/N) was obtained from the powders washed by acetic acid

Kong-jun Zhu; Li-kui Su; Hong-li Ji; Jin-hao Qiu

2008-01-01

21

Space Charge Effect in Lead Zirconate Titanate Ceramics Caused by the Addition of Impurities  

Microsoft Academic Search

Lead zirconate titanate ceramics containing metal oxides as impurities are subjected to poling, in order to give rise to piezoelectric activity, at various temperatures. Impurities contained in the ceramics are found to be divided into three groups according to their effects on poling temperatures. (1) When the amounts are small, piezoelectric activity is lowered by poling at low temperatures, but

Masao Takahashi

1970-01-01

22

Utilisation of smart polymers and ceramic based piezoelectric materials for scavenging wasted energy  

Microsoft Academic Search

Piezoelectric smart polymer and ceramic materials can be deployed as a mechanism to transform mechanical energy into electrical energy that can be stored and used to power portable devices. This paper focuses on the development and comparison of a micropower based harvesting generator using piezoelectric PZT (lead zirconate titanate) ceramic, PVDF (polyvinylidene fluoride) membrane and PP (polypropylene) foam polymer with

I. Patel; E. Siores; T. Shah

2010-01-01

23

Enhanced lateral electromechanical coupling in lead-titanate-rod\\/polymer piezoelectric composites  

Microsoft Academic Search

Although modified lead-titanate ceramics exhibit a negligible d31 piezoelectric coefficient, piezoelectric-rod\\/polymer-matrix composites made from them exhibit a substantial d31. A theoretical analysis shows that the composite's enhanced d31 coefficient arises from lateral stress on the polymer phase being transferred to a longitudinal stress along the ceramic rods by the Poisson effect in the polymer, thus producing a charge through the

WALLACE ARDEN SMITH; AVNER A. SHAULOV; ROBERT Y. TING

1988-01-01

24

Engineering domain configurations for enhanced piezoelectricity in barium titanate single crystals  

E-print Network

Engineering domain configurations for enhanced piezoelectricity in barium titanate single crystals piezoelectric responses of barium titanate single crystals under different crystallographic orientations, and use it to explain the ultrahigh piezoelectric response recently observed in a 270 cut barium titanate

Li, Jiangyu

25

Precipitation of Zirconia Phase in Niobium-Modified Ceramics of Lead Zirconate-Titanate  

Microsoft Academic Search

The piezoelectric performances of lead ziroconate-titanate ceramics are much improved by an addition of niobia, and they are called the ``modified'' ceramics by the staffs of the Clevite Research Center. Microscopic observation of these ceramics shows many pink precipitates segregating out of the grains. These parts are luminescent in the incidence of electron beam. The electron probe microanalysis reveals that

Takuro Ikeda; Yoichi Tanaka; Takako Ayakawa; Haruo Noake

1964-01-01

26

Fracture mechanics for piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

We Study cracks either in piezoelectrics, or on interfaces between piezoelectrics and other materials such as metal electrodes or polymer matrices. The projected applications include ferroelectric actuators operating statically or cyclically, over the major portion of the samples, in the linear regime of the constitutive curve, but the elevated field around defects causes the materials to undergo hysteresis locally. The fracture mechanics viewpoint is adopted—that is, except for a region localized at the crack tip, the materials are taken to be linearly piezoelectric. The problem thus breaks into two subproblems: (i) determining the macroscopic field regarding the crack tip as a physically structureless point, and (ii) considering the hysteresis and other irreversible processes near the crack tip at a relevant microscopic level. The first Subproblem, which prompts a phenomenological fracture theory, receives a thorough investigation in this paper. Griffith's energy accounting is extended to include energy change due to both deformation and polarization. Four modes of square root singularities are identified at the tip of a crack in a homogeneous piezoelectric. A new type of singularity is discovered around interface crack tips. Specifically, the singularities in general form two pairs: r {1}/{2}±i? and r {1}/{2}±i? , where ?. and k are real numbers depending on the constitutive constants. Also solved is a class of boundary value problems involving many cracks on the interface between half-spaces. Fracture mechanics are established for ferroelectric ceramics under smallscale hysteresis conditions, which facilitates the experimental study of fracture resistance and fatigue crack growth under combined mechanical and electrical loading. Both poled and unpoled fcrroelectrie ceramics are discussed.

Suo, Z.; Kuo, C.-M.; Barnett, D. M.; Willis, J. R.

1992-05-01

27

Finite Element Analysis of Piezoelectric Ceramic Speaker with Ansys Software  

E-print Network

ansys Finite Element Analysis of Piezoelectric Ceramic Speaker with Ansys Software 063 064090216 5 15 #12; 2010 5 15 #12; 3 3C (Mason) (Krimholtz) ansys ansys #12; ANSYS 4 Abstract The Piezoelectric ceramic piezoelectric speakers is a devices based

Wang, Ji

28

Compact pulse forming line using barium titanate ceramic material.  

PubMed

Ceramic material has very high relative permittivity, so compact pulse forming line can be made using these materials. Barium titanate (BaTiO(3)) has a relative permittivity of 1200 so it is used for making compact pulse forming line (PFL). Barium titanate also has piezoelectric effects so it cracks during high voltages discharges due to stresses developed in it. Barium titanate is mixed with rubber which absorbs the piezoelectric stresses when the PFL is charged and regain its original shape after the discharge. A composite mixture of barium titanate with the neoprene rubber is prepared. The relative permittivity of the composite mixture is measured to be 85. A coaxial pulse forming line of inner diameter 120 mm, outer diameter 240 mm, and length 350 mm is made and the composite mixture of barium titanate and neoprene rubber is filled between the inner and outer cylinders. The PFL is charged up to 120 kV and discharged into 5 ? load. The voltage pulse of 70 kV, 21 ns is measured across the load. The conventional PFL is made up of oil or plastics dielectrics with the relative permittivity of 2-10 [D. R. Linde, CRC Handbook of Chemistry and Physics, 90th ed. (CRC, 2009); Xia et al., Rev. Sci. Instrum. 79, 086113 (2008); Yang et al., Rev. Sci. Instrum. 81, 43303 (2010)], which increases the length of PFL. We have reported the compactness in length achieved due to increase in relative permittivity of composite mixture by adding barium titanate in neoprene rubber. PMID:22129008

Kumar Sharma, Surender; Deb, P; Shukla, R; Prabaharan, T; Shyam, A

2011-11-01

29

Compact pulse forming line using barium titanate ceramic material  

NASA Astrophysics Data System (ADS)

Ceramic material has very high relative permittivity, so compact pulse forming line can be made using these materials. Barium titanate (BaTiO3) has a relative permittivity of 1200 so it is used for making compact pulse forming line (PFL). Barium titanate also has piezoelectric effects so it cracks during high voltages discharges due to stresses developed in it. Barium titanate is mixed with rubber which absorbs the piezoelectric stresses when the PFL is charged and regain its original shape after the discharge. A composite mixture of barium titanate with the neoprene rubber is prepared. The relative permittivity of the composite mixture is measured to be 85. A coaxial pulse forming line of inner diameter 120 mm, outer diameter 240 mm, and length 350 mm is made and the composite mixture of barium titanate and neoprene rubber is filled between the inner and outer cylinders. The PFL is charged up to 120 kV and discharged into 5 ? load. The voltage pulse of 70 kV, 21 ns is measured across the load. The conventional PFL is made up of oil or plastics dielectrics with the relative permittivity of 2-10 [D. R. Linde, CRC Handbook of Chemistry and Physics, 90th ed. (CRC, 2009); Xia et al., Rev. Sci. Instrum. 79, 086113 (2008); Yang et al., Rev. Sci. Instrum. 81, 43303 (2010)], which increases the length of PFL. We have reported the compactness in length achieved due to increase in relative permittivity of composite mixture by adding barium titanate in neoprene rubber.

Kumar Sharma, Surender; Deb, P.; Shukla, R.; Prabaharan, T.; Shyam, A.

2011-11-01

30

Properties of 1-3-2 connectivity piezoelectric ceramic/polymer composite  

NASA Astrophysics Data System (ADS)

Epoxy resin and lead zirconate titanate (P-41) ceramic were respectively used as matrix and functional component to fabricate 1-3 and 1-3-2 connectivity piezoelectric ceramic-polymer composites by dice and filling method. The interface bonding condition between matrix and piezoelectric functional phase was investigated by using SEM. Piezoelectric properties, dielectric properties, electromechanical properties and acoustic impedance of the 1-3 and 1-3-2 connectivity piezoelectric composites were studied. The results show that the interface bonding of the two-phase materials is compact, comparing with the P-41 ceramic, the thickness electromechanical coupling coefficient Kt of both kinds of the composites is almost two times larger than that of P-41 ceramic, while the value of mechanical quality factor Qm and dielectric loss tan? are smaller, acoustic impedance Z and relative dielectric constant ?r are almost half of P-41 ceramic. The value of d33, g33, Kt, Qm, Z, ?r, and tan? of 1-3-2 connectivity piezoelectric composite are close to those of 1-3 connectivity piezoelectric composite, which show that the 1-3-2 connectivity piezoelectric composite can instead of 1-3 connectivity piezoelectric composite in special application field.

Liao, Shuangshuang; Huang, Shifeng; Xu, Dongyu; Cheng, Xin

2009-07-01

31

Shear-Mode Industrial Inkjet Head Using Lead-Free Piezoelectric Ceramics  

NASA Astrophysics Data System (ADS)

A shear-mode inkjet head utilizing alkaline niobate-based lead-free piezoelectric ceramics has been developed. A prototype inkjet head with a nozzle density 150 dots per inch (dpi) was achieved on a grayscale of eight levels with a minimum ink droplet ejection of 6 pl. Furthermore, the inkjet head with a nozzle density of 300 dpi was achieved on a grayscale of four levels with a minimum ink droplet ejection of 3 pl. Although the prototype inkjet head required a high voltage of approximately twice the driving voltage of the inkjet head using lead zirconate titanate (PZT) piezoelectric ceramics, the grayscale can be realized by a multidrop method. Thus, the alkaline niobate-based lead-free piezoelectric ceramics can be used to replace PZT ceramics as shear-mode actuators for inkjet heads.

Tanuma, Chiaki; Shimosato, Masashi; Nitta, Noboru; Yamamoto, Keizaburou; Takahashi, Hirofumi

2012-09-01

32

Porous Piezoelectric Ceramics—A Historical Overview  

Microsoft Academic Search

A brief review of porosity origin, microstructure peculiarities, fabrication methods, and mathematical models, as well as experimental data for different porous piezoceramics were presented. Critical comparison of FEM calculations with the results of various approximated formulas, unit cell models, and experimental data for porous piezoceramics was carried out. Complex sets of elastic, dielectric and piezoelectric coefficients of porous ceramics were

Andrey N. Rybyanets

2011-01-01

33

Porous Piezoelectric Ceramics - A historical overview  

Microsoft Academic Search

A brief review of porosity origin, microstructure peculiarities, fabrication methods, and mathematical models, as well as experimental data for different porous piezoceramics were presented. Critical comparison of FEM calculations with the results of various approximated formulas, unit cell models, and experimental data for porous piezoceramics was carried out. Complex sets of elastic, dielectric and piezoelectric coefficients of porous ceramics were

Andrey N. Rybyanets

2010-01-01

34

Effect of dielectrophoretic structuring on piezoelectric and pyroelectric properties of lead titanate-epoxy composites  

NASA Astrophysics Data System (ADS)

Functional granular composites of lead titanate particles in an epoxy matrix prepared by dielectrophoresis show enhanced dielectric, piezoelectric and pyroelectric properties compared to 0–3 composites for different ceramic volume content from 10% to 50%. Two structuring parameters, the interparticle distance and the percentage of 1–3 connectivity are used based on the Bowen model and the mixed connectivity model respectively. The degree of structuring calculated according to both models correlate well with the increase in piezoelectric and pyroelectric sensitivities of the composites. Higher sensitivity of the electroactive properties are observed at higher ceramic volume fractions. The effect of electrical conductivity of the matrix on the pyroelectric responsivity of the composites has been demonstrated to be a key parameter in governing the pyroelectric properties of the composites.

Khanbareh, H.; van der Zwaag, S.; Groen, W. A.

2014-10-01

35

Dielectric and Piezoelectric Properties of Barium Titanate  

Microsoft Academic Search

The dielectric constant and loss of barium titanate and barium-strontium titanate have been measured at biasing field strengths from 0 to 5 megavolts per meter, at temperatures from -50°C to +135°C and at frequencies from 0.1 to 25 megacycles. The measurements versus temperature indicate the expected agreement with the Curie-Weiss law at temperatures above the Curie point. Measurements versus field

Shepard Roberts

1947-01-01

36

Numerical characterization of soft piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

Numerical simulations of piezoelectric ceramics can give detailed information about their static and dynamic behaviours. Resonance frequencies, mechanical displacements and other values of interest can be obtained using well known techniques, such as Finite Element Method (FEM). However, the predictions of such methods are strongly limited by the accuracy of the parameters in the piezoceramic model. Assuming a linear behaviour, five elastic constants, three piezoelectric constants, two dielectric constants and the mass density are needed to simulate piezoceramics belonging to the 6-mm symmetry class. In a recent work, our research group presents a novel methodology to obtain the parameters of piezoelectric ceramic disks based on FEM simulations in a set of ten hard PZT ceramics. In this work, the proposed methodology is applied for the characterization of two soft PZT ceramics (Pz27 from Ferroperm and APC850 from APC International) typically used in ultrasound applications. To provide the error bound two different thicknesses (frequencies of 1 MHz and 2 MHz) and three different diameters (10 mm, 20 mm and 30 mm) are used in the characterization, the mean value over this set is used to characterize the material itself. A set of ten samples belonging to a single fabrication batch is used to estimate the error bound for identical samples. The results adjust the impedance curves over a wide band of frequencies, including the radial modes, the thickness mode and other coupled modes.

Pérez, Nicolás; Buiochi, Flavio; Andrade, Marco A. B.; Adamowski, Julio C.

2012-05-01

37

Development of a Templated Grain Growth System for Texturing Piezoelectric Ceramics  

E-print Network

Development of a Templated Grain Growth System for Texturing Piezoelectric Ceramics MATTHEW M be obtained from crystallographically textured piezoelectric ceramics. Single crystal piezoelectrics costs. NexTech Materials is developing textured piezoelectrics via Templated Grain Growth

Azad, Abdul-Majeed

38

Anomalies of piezoelectric coefficients in barium titanate thin films  

NASA Astrophysics Data System (ADS)

Modeling of electromechanical devices involves the use of different material coefficients, whose measurement is a difficult task, especially when the problem concerns thin films. Required coefficients of thin films could be found theoretically, using known values of the bulk constants. Electromechanical coefficients of barium titanate thin films are still unknown; therefore, it is expedient to carry out their calculations. We give here the full set of electromechanical coefficients of barium titanate thin films for the whole range of technologically available misfit strains. In the present paper, piezoelectric coefficients as functions of a misfit strain were calculated. It was revealed that piezoelectric coefficients exhibit anomalies at phase boundaries and inside the monoclinic r-phase as well. The obtained results allow finding the required values of the thin-film parameters, varying the misfit strain.

Shirokov, Vladimir; Kalinchuk, Valery; Shakhovoy, Roman; Yuzyuk, Yury

2014-11-01

39

Elastic and Piezoelectric Coefficients of Single-Crystal Barium Titanate  

Microsoft Academic Search

Mechanical resonance and antiresonance frequencies were measured on barium titanate single-crystal elements maintained under electric dc bias from -50°C to +150°C. A complete set of elastic, piezoelectric, and dielectric constants of the tetragonal modification at 25°C is obtained. The elastic compliances show substantial deviation from cubic symmetry. Measurements in the orthorhombic state show longitudinal compliance four times higher than in

Don Berlincourt; Hans Jaffe

1958-01-01

40

Magnetoelectric behavior of Terfenol-D composite and lead zirconate titanate ceramic laminates  

Microsoft Academic Search

Five magnetoelectric laminates of polymer-bonded Terfenol-D magnetostrictive composite (i.e., volume fractions (Vp) ranging from 0.16 to 0.48) and lead zirconate titanate (PZT-5H) piezoelectric ceramic were fabricated. The measured quasistatic magnetoelectric voltage coefficient (?E) increased gradually with increasing Vp and approached saturation for Vp>0.4 due to increased elastic modulus and piezomagnetic coefficient of the magnetostrictive phase. A maximum ?E of 2.7

Nersesse Nersessian; Siu Wing; G. P. Carman

2004-01-01

41

Piezoelectric and pyroelectric properties of lead titanate-polyethylene oxide composites  

NASA Astrophysics Data System (ADS)

Polymer-ceramic composites with pyroelectric sensitivity are presented as promising candidates for infrared detection. Selection of the appropriate ceramic filler and the polymer matrix is one of the key parameters in the development of optimized materials for specific applications. In this work lead-titanate (PT) ceramic is incorporated into a flexible polymer matrix, polyethylene oxide (PEO) with relatively high electrical conductivity to develop sensitive and at the same time flexible composites. PT particles are dispersed in PEO at varying volume fractions, and composite materials cast in the form of films for the measurements. The dielectric, piezoelectric and pyroelectric properties are measured. From these data the piezoelectric voltage coefficients as well as pyroelctric figures of merit of the composite films have been determined and values were compared with that of PT-epoxy composites in order to determine the effect of electrical conductivity of the polymer matrix on the poling efficiency and the final properties. It is found that, in general, both the piezoelectric and the pyroelectric figures of merit increase with concentration of PT; however, it is at the expense of mechanical flexibility of the material. Moreover PT-PEO composites show superior pyroelectric sensitivity compared to PT-Epoxy composites. Improving the electrical conductivity of the polymer phase enhances the poling process significantly.

Khanbareh, H.; van der Zwaag, S.; Groen, W. A.

2014-11-01

42

Piezoelectric and pyroelectric properties of conductive polyethylene oxide-lead titanate composites  

NASA Astrophysics Data System (ADS)

Polymer-ceramic composites with pyroelectric sensitivity are presented as promising candidates for sensing applications. Selection of the appropriate ceramic filler and the polymer matrix is one of the key parameters in the development of optimized materials for specific applications. In this work lead-titanate (PT) ceramic particulate is incorporated into a polymer matrix, polyethylene oxide (PEO) with a relatively high electrical conductivity to develop sensitive and at the same time flexible composites. PT particles are dispersed in PEO at varying volume fractions, and composite materials are cast in the form of films to measure their dielectric, piezoelectric and pyroelectric properties. From these data the piezoelectric voltage coefficients as well as pyroelctric figures of merit of the composite films have been determined. In order to determine the effect of electrical conductivity of the polymer matrix on the poling efficiency and the final properties, a poling study has been performed. Improving the electrical conductivity of the polymer phase enhances the poling process significantly. It is found that both the piezoelectric and the pyroelectric figures of merit increase with concentration of PT. PT–PEO composites show superior pyroelectric sensitivity compared to other composites with less conductive polymer matrices.

Khanbareh, H.; van der Zwaag, S.; Groen, W. A.

2015-04-01

43

Dielectric, ferroelectric, and piezoelectric properties of lead zirconate titanate thick films on silicon substrates  

NASA Astrophysics Data System (ADS)

This article reports the fabrication of thick films of lead zirconate titanate (PZT) on platinum-buffered silicon substrates by screen printing. Crack-free films, up to 12 ?m on a single pass, show a dielectric permittivity of 200, tangent losses of 0.05, remanent polarization of 2.5 ?C/cm2, and coercive field of 40 kV/cm. The field-induced longitudinal piezoelectric coefficient d33 at 40 kV/cm dc bias and 4 kV/cm alternating field corresponded to 50 pC/N. The magnitude of the piezoelectric voltage coefficient g33, computed from the strain coefficient and dielectric permittivity, under the same conditions, was found to be 36×10-3 V m/N, higher than that of a poled PZT bulk ceramic in comparison. These results are promising for a broad variety of sensor applications.

Chen, H. D.; Udayakumar, K. R.; Cross, L. E.; Bernstein, J. J.; Niles, L. C.

1995-04-01

44

A Calculation of Physical Constants of Ceramic Barium Titanate  

Microsoft Academic Search

The dielectric, piezoelectric and elastic constants of polycrystalline ceramics at room temperature are calculated by averaging those values of single crystals on the assumption that the ceramic is composed of spherical crystallites. The calculated values are in good agreement with observed ones, showing that the piezoelectric effects in each single crystal (especially d15 at room temp.) play a great part

Masakazu Marutake

1956-01-01

45

Current Developments and Prospective of Lead-Free Piezoelectric Ceramics  

Microsoft Academic Search

The dielectric, ferroelectric and piezoelectric properties of perovskite ferroelectric and bismuth layered-structured ferroelectric (BLSF) ceramics are described being superior candidates for lead-free piezoelectric materials to reduce environmental damage. Perovskite-type ceramics seem to be suitable for actuator and high-power applications that require a large piezoelectric constant, d33, and a high Curie temperature, Tc, or a depolarization temperature, Td (>200 °C). For

Tadashi Takenaka; Hajime Nagata; Yuji Hiruma

2008-01-01

46

Current status and prospects of lead-free piezoelectric ceramics  

Microsoft Academic Search

Dielectric, ferroelectric and piezoelectric properties of perovskite ferroelectric and bismuth layer-structured ferroelectric (BLSF) ceramics are described as superior candidates for lead-free piezoelectric materials to reduce environmental damages. Perovskite type ceramics seem to be suitable for actuator and high power applications that are required a large piezoelectric constant, d33 (>300pC\\/N) and a high Curie temperature, Tc (>200°C). For BaTiO3 (BT)-based solid

Tadashi Takenaka; Hajime Nagata

2005-01-01

47

Measuring droplet impact with piezoelectric film  

E-print Network

materials used in piezoelectric applications were barium titanate, rochelle salt and quartz (Klapholz, 1985). During World War H, researchers found that ceramics have high piezoelectric response. By 1960, researchers found that the polyvinylidene fluoride...

Basahi, Jalal M. Al-Badry M.

1993-01-01

48

Improving the dielectric and piezoelectric properties of screen-printed Low temperature PZT/polymer composite  

E-print Network

PZT, Barium titanate BeTiO3) are brittle but offer high d33 (350-560 pC/N) and high dielectric materials, ceramics, polymers and composites. Ceramic piezoelectric materials (e.g. lead zirconate titanate

49

The enhanced and optimal piezoelectric coefficients in single crystalline barium titanate with engineered domain configurations  

E-print Network

The enhanced and optimal piezoelectric coefficients in single crystalline barium titanate the effective electromechanical moduli of tetragonal barium titanate poled along 111 direction, where that poling along 111 direction does not lead to the optimal domain configuration, since barium titanate poled

Li, Jiangyu

50

Resonant magnetoelectric coupling in trilayers of ferromagnetic alloys and piezoelectric lead zirconate titanate: The influence of bias magnetic field  

E-print Network

- magnetic phase and barium titanate, lead magnesium niobate-lead titanate, or lead zirconate titanate PZT zirconate titanate: The influence of bias magnetic field G. Srinivasan and C. P. De Vreugd Physics-piezoelectric heterostructures. Trilayers of Permendur, a Co-Fe-V alloy, and lead zirconate titanate were studied. Measurements

Srinivasan, Gopalan

51

Migration and redistribution of oxygen vacancy in barium titanate ceramics  

SciTech Connect

Degradation of barium titanate based multilayer capacitor mainly results from migration and redistribution of oxygen vacancy. For barium titanate ceramics, the authors observe an internal friction relaxation peak around 70 deg. C due to oxygen vacancy, and its relaxation strength differs greatly for specimen aged at 85 deg. C for 120 h and at 150 deg. C for 5 h. Two possible explanations are proposed, one based on symmetry-conforming short-range order while the other on the interaction between oxygen vacancy and domain wall during aging process. In any case, relaxation thermodynamics is a powerful tool to investigate the migration and redistribution of oxygen vacancy in barium titanate ceramics.

Chen, L.; Xiong, X. M.; Meng, H.; Lv, P.; Zhang, J. X. [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

2006-08-14

52

Embedded piezoelectric ceramic transducers in sandwiched beams  

NASA Astrophysics Data System (ADS)

Surface bonded piezoelectric ceramic (PZT) transducers are currently the most prominent area of research in structural health monitoring using electromechanical impedance methods. This paper presents a new embedded PZT patch and its interaction with the host sandwiched beam. Durability and protection from surface finish, vandalism and the environment are important features of the embedment. The paper also demonstrates the use of thickness vibration of the PZT patch in electromechanical admittance formulations. This embedded PZT-structure interaction model is based on the new concept of 'average sum impedance'. The formulations used for this model can be conveniently employed to extract the mechanical impedance of any 'unknown' PZT patch embeddable plane structure. The mechanical impedance of the structure is obtained from the admittance signatures of the embedded PZT patch. The proposed model is experimentally verified on sandwiched beams.

Gopal Madhav Annamdas, Venu; Kiong Soh, Chee

2006-04-01

53

High-Temperature Piezoelectric Ceramic Developed  

NASA Technical Reports Server (NTRS)

Active combustion control of spatial and temporal variations in the local fuel-to-air ratio is of considerable interest for suppressing combustion instabilities in lean gas turbine combustors and, thereby, achieving lower NOx levels. The actuator for fuel modulation in gas turbine combustors must meet several requirements: (1) bandwidth capability of 1000 Hz, (2) operating temperature compatible with the fuel temperature, which is in the vicinity of 400 F, (3) stroke of approximately 4 mils (100 m), and (4) force of 300 lb-force. Piezoelectric actuators offer the fastest response time (microsecond time constants) and can generate forces in excess of 2000 lb-force. The state-of-the-art piezoceramic material in industry today is Pb(Zr,Ti)O3, called PZT. This class of piezoelectric ceramic is currently used in diesel fuel injectors and in the development of high-response fuel modulation valves. PZT materials are generally limited to operating temperatures of 250 F, which is 150 F lower than the desired operating temperature for gas turbine combustor fuel-modulation injection valves. Thus, there is a clear need to increase the operating temperature range of piezoceramic devices for active combustion control in gas turbine engines.

Sayir, Ali; Farmer, Serene C.; Dynys, Frederick W.

2005-01-01

54

Development of a stress sensor based on the piezoelectric lead zirconate titanate for impact stress measurement  

NASA Astrophysics Data System (ADS)

The measurement of stress of concrete structures under impact loading and other strong dynamic loadings is crucial for the monitoring of health and damage detection. Due to its main advantages including availability, extremely high rigidity, high natural frequency, wide measuring range, high stability, high reproducibility, high linearity and wide operating temperature range, piezoelectric (Lead Zirconate Titanate, PZT) ceramic materials has been a widely used smart material for both sensing and actuation for monitoring and control in engineering structures. In this paper, a kind of stress sensor based on piezoelectric ceramics for impact stress measuring of concrete structures is developed. Because the PZT is fragile, in order to employ it for the health monitoring of concrete structures, special handling and treatment should be taken to protect the PZT and to make it survive and work properly in concrete. The commercially available PZT patch with lead wires is first applied with an insulation coating to prevent water and moisture damage, and then is packaged by jacketing it by two small precasted cylinder concrete blocks with enough strength to form a smart aggregate (SA). The employed PZT patch has a dimension of 10mm x 10mm x 0.3mm. In order to calibrate the PZT based stress sensor for impact stress measuring, a dropping hammer was designed and calibration test on the sensitivity of the proposed transducer was carried out with an industry charge amplifier. The voltage output of the stress sensor and the impact force under different free falling heights and impact mass were recorded with a high sampling rate data acquisition system. Based on the test measurements, the sensibility of the PZT based stress sensor was determined. Results show that the output of the PZT based stress sensor is proportional to the stress level and the repeatability of the measurement is very good. The self-made piezoelectric stress sensor can be easily embedded in concrete and provide reliable stress sensing under dynamic loadings.

Liu, Yiming; Xu, Bin; Li, Lifei; Li, Bing

2012-04-01

55

Development of a stress sensor based on the piezoelectric lead zirconate titanate for impact stress measurement  

NASA Astrophysics Data System (ADS)

The measurement of stress of concrete structures under impact loading and other strong dynamic loadings is crucial for the monitoring of health and damage detection. Due to its main advantages including availability, extremely high rigidity, high natural frequency, wide measuring range, high stability, high reproducibility, high linearity and wide operating temperature range, piezoelectric (Lead Zirconate Titanate, PZT) ceramic materials has been a widely used smart material for both sensing and actuation for monitoring and control in engineering structures. In this paper, a kind of stress sensor based on piezoelectric ceramics for impact stress measuring of concrete structures is developed. Because the PZT is fragile, in order to employ it for the health monitoring of concrete structures, special handling and treatment should be taken to protect the PZT and to make it survive and work properly in concrete. The commercially available PZT patch with lead wires is first applied with an insulation coating to prevent water and moisture damage, and then is packaged by jacketing it by two small precasted cylinder concrete blocks with enough strength to form a smart aggregate (SA). The employed PZT patch has a dimension of 10mm x 10mm x 0.3mm. In order to calibrate the PZT based stress sensor for impact stress measuring, a dropping hammer was designed and calibration test on the sensitivity of the proposed transducer was carried out with an industry charge amplifier. The voltage output of the stress sensor and the impact force under different free falling heights and impact mass were recorded with a high sampling rate data acquisition system. Based on the test measurements, the sensibility of the PZT based stress sensor was determined. Results show that the output of the PZT based stress sensor is proportional to the stress level and the repeatability of the measurement is very good. The self-made piezoelectric stress sensor can be easily embedded in concrete and provide reliable stress sensing under dynamic loadings.

Liu, Yiming; Xu, Bin; Li, Lifei; Li, Bing

2011-11-01

56

Temperature dependence of piezoelectric properties for textured SBN ceramics  

Microsoft Academic Search

Temperature dependences of piezoelectric properties were studied for (001) textured ceramics of bismuth layer-structured ferroelectrics, SrBi2Nb2O9 (SBN). The textured ceramics with varied orientation degrees were fabricated by templated, grain-growth method, and the temperature dependences of resonance frequency were estimated. Excellent temperature stability of resonance frequency was obtained for the 76% textured ceramics. The resonance frequency of the 76% textured specimens

Masahiko Kimura; Hirozumi Ogawa; Daisuke Kuroda; Takuya Sawada; Yukio Higuchi; Hiroshi Takagi; Yukio Sakabe

2007-01-01

57

Influence of sample size on ultrasonic phase velocity measurements in piezoelectric ceramics  

E-print Network

Influence of sample size on ultrasonic phase velocity measurements in piezoelectric ceramics Rui Piezoelectric materials are widely used in various elec- tromechanical devices. Along with density and permittivity, elastic and piezoelectric constants are the fundamental pa- rameters of these materials

Cao, Wenwu

58

Effect of electrical and mechanical poling history on domain orientation and piezoelectric properties of soft and hard PZT ceramics  

NASA Astrophysics Data System (ADS)

The superior piezoelectric properties of all polycrystalline ferroelectrics are based on the extent of non-180° domain wall motion under electrical and mechanical poling loads. To distinguish between 180° and non-180° domain wall motion in a soft-doped and a hard-doped lead zirconate titanate (PZT) ceramic, domain texture measurements were performed using x-ray and neutron diffraction after different loading procedures. Comparing the results to measurements of the remanent strain and piezoelectric coefficient allowed the differentiation between different microstructural contributions to the macroscopic parameters. Both types of ceramic showed similar behavior under electric field, but the hard-doped material was more susceptible to mechanical load. A considerable fraction of the piezoelectric coefficient originated from poling by the preferred orientation of 180° domains.

Marsilius, Mie; Granzow, Torsten; Jones, Jacob L.

2011-02-01

59

Dielectric behaviors of lead zirconate titanate ceramics with coplanar electrodes  

Microsoft Academic Search

This paper reports on the dielectric behaviors of lead zirconate titanate (PZT) capacitors with coplanar electrodes. Usually a ferroelectric device has a metal-ferroelectric-metal configuration (parallel plate capacitor); when both the electrodes are on one side of a ceramic to form a coplanar capacitor, different dielectric behaviors will be anticipated because of the change in the distribution of the test field

Y Wang; Y. L Cheng; Y. W Zhang; H. L. W Chan; C. L Choy

2003-01-01

60

Current Developments and Prospective of Lead-Free Piezoelectric Ceramics  

NASA Astrophysics Data System (ADS)

The dielectric, ferroelectric and piezoelectric properties of perovskite ferroelectric and bismuth layered-structured ferroelectric (BLSF) ceramics are described being superior candidates for lead-free piezoelectric materials to reduce environmental damage. Perovskite-type ceramics seem to be suitable for actuator and high-power applications that require a large piezoelectric constant, d33, and a high Curie temperature, Tc, or a depolarization temperature, Td (>200 °C). For BaTiO3-based solid solutions, (1-x)BaTiO3-x(Bi0.5K0.5)TiO3 (BT-BKT100x) ceramics, Tc increases with increasing amount of x. The BT-BKT20 + MnCO3 (0.1 wt %) ceramic shows a high Tc greater than 200 °C and an electromechanical coupling factor of k33 =0.35. In the case of a(Bi1/2Na1/2)TiO3-b(Bi1/2K1/2)TiO3-cBaTiO3 [BNBK (100a/100b/100c)] solid solution ceramics, d33 is 191 pC/N for BNBK (85.2/2.8/12). KNbO3 (KN)-based ceramics are also a candidate for lead-free piezoelectrics. In Mn-doped KN ceramics, a higher k33 of 0.507 is obtained for KN + MnCO3 (0.1 wt %). On the other hand, BLSF ceramics seem to be excellent candidates as piezoelectric sensors for high temperatures and ceramic resonators with a high mechanical quality factor, Qm, and a low temperature coefficient of resonance frequency, TC-f. The k33 value of the donor (Nb)-doped and grain-oriented (HF) Bi4Ti3-xNbxO12 (BITN-x) ceramic is 0.39 for x=0.08 and is able to keep the same stable value up to 350 °C. Nd(0.01) and V(0.75) co-doped Bi4Ti3O12 ceramics, BNTV(0.01, 0.75), show a relatively low TC-f. Bi3TiTaO9 (BTT)-based solid solution, Srx-1Bi4-xTi2-xTaxO9 [SBTT2(x)] (1?x?2), displays the high Qm value (=13500) in (p)-mode at x=1.25. For resonator applications, (Sr1-xCax)2Bi4Ti5O18 (SCBT) (0?x?0.5) ceramics are suitable.

Takenaka, Tadashi; Nagata, Hajime; Hiruma, Yuji

2008-05-01

61

Manufacturing of PZT-nickel functionally graded piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

A recent approach for designing and manufacturing piezoelectric ceramics consists of using the functionally graded materials (FGM) concept. In this work, nickel (Ni) is used to generate a new PZT-Ni graded ceramic and its dynamic behavior is experimentally explored. The PZT-Ni graded ceramic is manufactured by using the technique of Spark Plasma Sintering (SPS). The ceramic is graded from the top to the bottom surface (along 6 mm of thickness). Specifically, five layers of green powders are sintered: 100 wt% PZT-5A, 90 wt% PZT-5A and 10 wt% Ni, 80 wt% PZT-5A and 20 wt% Ni, 70 wt% PZT-5A and 30 wt% Ni, 60 wt% PZT-5A and 40 wt% Ni. Thus, Ni is used as a second phase, which is added to a PZT-5A matrix, changing its concentration. No manufacturing defects or cracks or exfoliated layers are observed. However, graphite diffusion is observed from the graphite die into the graded ceramic, which does not affect its performance; hence, the ceramic contains enough piezoelectric properties, which allows its polarization and dynamic characterization by determining the impedance curve of the PZT-Ni graded ceramic. The PZT-Ni graded ceramic vibrates at 1.04 MHz, 1.55 MHz and 2.07 MHz.

Rubio, Wilfredo M.; Silva, Emílio C. N.; Buiochi, Flávio

2012-05-01

62

Nyquist Relation and Its Validity for Piezoelectric Ceramics Considering Temperature  

NASA Astrophysics Data System (ADS)

In this paper, we focused on validity of the Nyquist relation for piezoelectric ceramics in temperatures 303 K-393 K. The electrical impedance and noise spectral density were measured and compared for every 10 K in frequency range 100 kHz-1 MHz. The measurements were made in thermal stable condition and under equilibrium conditions in the case of noise measurement.

Sedlak, Petr; Majzner, Jiri; Sikula, Josef

2009-04-01

63

Modeling Time-dependent Responses of Piezoelectric Fiber Composite  

E-print Network

Ga 5 SiO 14 ). Man-made ceramics are barium titanate (BaTiO 3 ), lead titanate (PbTiO 3 ), lead zirconate titanate (Pb[Zr x Ti 1-x ]O 3 0titanate (PZT), lead titanate (PT) and barium titanate (BT). The electro-mechanical properties of PZT, PT, and BT are given in Table 1.1. PZT has relatively high compliance and high piezoelectric...

Li, Kuo-An

2011-02-22

64

Enhanced Piezoelectric Property of Barium Titanate Single Crystals with Engineered Domain Configurations  

Microsoft Academic Search

Piezoelectric properties of barium titanate single crystals wereinvestigated at room temperature as a function of crystallographicorientation. When a unipolar electric field was applied along [001],its strain vs electric-field curve showed a large hysteresis,and finally barium titanate crystal became to single-domain state withpiezoelectric constant d33 of 125 pC\\/N over 20 kV\\/cm. On theother hand, electric-field exposure below 6 kV\\/cm along [111]resulted

Satoshi Wada; Shingo Suzuki; Tatsuo Noma; Takeyuki Suzuki; Minoru Osada; Masato Kakihana; Seung-Eek Park; L. Eric Cross; Thomas R. Shrout

1999-01-01

65

Study on the sandwich piezoelectric ceramic ultrasonic transducer in thickness vibration  

Microsoft Academic Search

A sandwich piezoelectric ceramic ultrasonic transducer in thickness vibration is studied. The transducer consists of front and back metal masses, and coaxially segmented, thickness polarized piezoelectric ceramic thin rings. For this kind of sandwich piezoelectric transducers in thickness vibration, it is required that the lateral dimension of the transducer is sufficiently large compared with its longitudinal dimension so that no

Shuyu Lin; Hua Tian

2008-01-01

66

STABILIZED BARIUM TITANATE CERAMICS FOR CAPACITOR DIELECTRICS  

Microsoft Academic Search

The effects of additions of LaâOâ and LaâOâ--; 3TiOâ on the electronic properties of barium titanate were investigated. ; It was found that small additions of the components markedly increase the ; lifetime of the material subjected to d-c fields of 50 v per mil at 200 l ; C. (auth);

J. B. MacChesney; P. K. Gallagher; F. V. DiMarcello

1963-01-01

67

Dielectric behavior of barium modified strontium bismuth titanate ceramic  

SciTech Connect

Barium Modified Strontium Bismuth Titanate(SBT) ceramic with general formula Sr1?xBaxBi4Ti4O15 is prepared by solid state reaction route. The structural analysis of the ceramics was done by X-ray diffraction technique. The X-ray patterns show that all the compositions are of single phase with orthorhombic structure. The temperature dependent dielectric behavior shows that the transition temperature decreases with Ba content but the maximum dielectric constant increases. The decreases of the transition with increase in Ba{sup 2+} ion, may be due to the decrease of orthorhombicity by the incorporation of Ba{sup 2+} ion in SBT lattice.

Nayak, P., E-mail: priyambada.pce@gmail.com [Department of Physics, National Institute of Technology, Rourkela, Odisha-769008 (India); Badapanda, T. [Department of Physics, C.V. Raman College of Engineering, Bhubaneswar, Odisha-752054 (India); Anwar, S.; Panigrahi, S. [Colloids and Materials Chemistry, Institute of Minerals and Materials Technology, Bhubaneswar, Odisha-751013 (India)

2014-04-24

68

Imaging of Acoustic Waves in Piezoelectric Ceramics by Coulomb Coupling  

NASA Astrophysics Data System (ADS)

The transport properties of bulk and guided acoustic waves travelling in a lead zirconate titanate (PZT) disc, originally manufactured to serve as ultrasonic transducer, have been monitored by scanned Coulomb coupling. The images are recorded by excitation and detection of ultrasound with local electric field probes via piezoelectric coupling. A narrow pulse has been used for excitation. Broadband coupling is achieved since neither mechanical nor electrical resonances are involved. The velocities of the traveling acoustic waves determined from the images are compared with characteristic velocities calculated from material properties listed by the manufacturer of the PZT plate.

Habib, Anowarul; Shelke, Amit; Pluta, Mieczyslaw; Kundu, Tribikram; Pietsch, Ullrich; Grill, Wolfgang

2012-07-01

69

KNN-NTK composite lead-free piezoelectric ceramic  

NASA Astrophysics Data System (ADS)

A (K,Na)NbO3-based lead-free piezoelectric ceramic was successfully densified. It exhibited an enhanced electromechanical coupling factor of kp = 0.52, a piezoelectric constant d33 = 252 pC/N, and a frequency constant Np = 3170 Hz m because of the incorporation of an elaborate secondary phase composed primarily of KTiNbO5. The ceramic's nominal composition was 0.92K0.42Na0.44Ca0.04Li0.02Nb0.85O3-0.047K0.85Ti0.85Nb1.15O5-0.023BaZrO3-0.0017Co3O4-0.002Fe2O3-0.005ZnO, abbreviated herein as KNN-NTK composite. The KNN-NTK ceramic exhibited a dense microstructure with few microvoids which significantly degraded its piezoelectric properties. Elemental maps recorded using transmission electron microscopy with energy-dispersive X-ray spectroscopy (TEM-EDS) revealed regions of high concentrations of Co and Zn inside the NTK phase. In addition, X-ray diffraction patterns confirmed that a small portion of the NTK phase was converted into K2(Ti,Nb,Co,Zn)6O13 or CoZnTiO4 by a possible reaction between Co and Zn solutes and the NTK phase during a programmed sintering schedule. TEM studies also clarified a distortion around the KNN/NTK interfaces. Such an NTK phase filled voids between KNN particles, resulting in an improved chemical stability of the KNN ceramic. The manufacturing process was subsequently scaled to 100 kg per batch for granulated ceramic powder using a spray-drying technique. The properties of the KNN-NTK composite ceramic produced using the scaled-up method were confirmed to be identical to those of the ceramic prepared by conventional solid-state reaction sintering. Consequently, slight changes in the NTK phase composition and the distortion around the KNN/NTK interfaces affected the KNN-NTK composite ceramic's piezoelectric characteristics.

Matsuoka, T.; Kozuka, H.; Kitamura, K.; Yamada, H.; Kurahashi, T.; Yamazaki, M.; Ohbayashi, K.

2014-10-01

70

Piezoelectric ceramic assembly tubes for torsional actuators  

NASA Astrophysics Data System (ADS)

The efforts described here are intended to provide a basis for the utilization of novel piezoelectric actuators in smart materials and structures. The actuator design developed in this study is a segmented, piezoelectric tube, with the individual segments driven in a d15 shear mode. The PZT-5A tubes were cut longitudinally in to an even number of equal slender segments. These slender segments were poled individually along their length using a continuous poling technique developed at NRL. The polarization of the poled segments alternates in direction between adjacent segments. The segments were reassembled with a conductive epoxy so that it serves as both joint and electrode. The assembled actuator tubes were evaluated by applying electric field normal to the polarization direction of the segments, demonstrating proof of concept. These solid state prototype devices were driven to precise angular displacement and torque output. Reliability test, including both fatigue and mechanical loading of the device, were conducted. In conjunction with this effort, numerical computation analyses were performed with respect to structural integrity versus segment joint thickness, and the relative effect of cylindrical versus polygonal configurations. These studies facilitated the successful production of prototypes. Projected actuator outputs based on electromechanical test results are also discussed in terms of requirements for noise and vibration control of helicopter rotor blades.

Kim, Chulho; Glazounov, Alexandre E.; Flippen, Luther D.; Pattnaik, Amitav; Zhang, Qi Ming; Lewis, David, III

1999-07-01

71

Realization of high-energy density polycrystalline piezoelectric ceramics  

SciTech Connect

This letter reports a high energy density piezoelectric material in the system given as: Pb[(Zr{sub 0.52}Ti{sub 0.48})O{sub 3}]{sub 1-x}[(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}]{sub x}+yMnCO{sub 3}, where x=0.1 and y varies from 0.5 to 0.9 wt %. A piezoelectric material with high energy density is characterized by a high product of piezoelectric voltage constant (g) and piezoelectric strain constant (d). The condition for obtaining large magnitude of g constant was derived to be as |d|={epsilon}{sup n}, where {epsilon} is the permittivity of the material and n is constant having lower bound of 0.5. It was found that for all practical polycrystalline piezoelectric ceramic materials the magnitude of n lies in the range of 1.1-1.30 and as the magnitude of n decreases towards unity a giant enhancement in the magnitude of g was obtained. A two step sintering process was developed to optimize a polycrystalline ceramic composition with low magnitude of n. For the optimized composition the value of g{sub 33} and d{sub 33} was found to be 55.56x10{sup -3} m{sup 2}/C and 291x10{sup -12} C/N, respectively, yielding the magnitude product d{sub 33}{center_dot}g{sub 33} as {approx}16168x10{sup -15} m{sup 2}/N which is significantly higher than the reported values in literature. The magnitude of n for this composition was calculated to be 1.151. This material is extremely promising for immediate applications in the sensing and energy harvesting.

Islam, Rashed Adnan; Priya, Shashank [Material Science and Engineering, University of Texas at Arlington, Arlington, Texas 76019 (United States)

2006-01-16

72

Realization of high-energy density polycrystalline piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

This letter reports a high energy density piezoelectric material in the system given as: Pb[(Zr0.52Ti0.48)O3]1-x[(Zn1/3Nb2/3)O3]x+yMnCO3, where x =0.1 and y varies from 0.5to0.9wt%. A piezoelectric material with high energy density is characterized by a high product of piezoelectric voltage constant (g) and piezoelectric strain constant (d). The condition for obtaining large magnitude of g constant was derived to be as ?d?=?n, where ? is the permittivity of the material and n is constant having lower bound of 0.5. It was found that for all practical polycrystalline piezoelectric ceramic materials the magnitude of n lies in the range of 1.1-1.30 and as the magnitude of n decreases towards unity a giant enhancement in the magnitude of g was obtained. A two step sintering process was developed to optimize a polycrystalline ceramic composition with low magnitude of n. For the optimized composition the value of g33 and d33 was found to be 55.56×10-3m2/C and 291×10-12C/N, respectively, yielding the magnitude product d33•g33 as ˜16168×10-15m2/N which is significantly higher than the reported values in literature. The magnitude of n for this composition was calculated to be 1.151. This material is extremely promising for immediate applications in the sensing and energy harvesting.

Islam, Rashed Adnan; Priya, Shashank

2006-01-01

73

Piezoelectric ultrathin lead titanate films prepared by deposition of aquo-diol solutions.  

PubMed

We report on the preparation of continuous ultrathin ferroelectric films of pure lead titanate by chemical solution deposition (CSD) methods. Aquo-diol solutions highly diluted have been used to obtain films with thickness down to approximately 13 nm, the lowest reported for CSD films. The formation of islands instead of continuous coatings, which has been reported when CSD is used to prepare ultrathin films, is avoided here. The piezoelectric activity of the films has been characterized by piezoresponse. force microscopy, showing that the thinnest film obtained retains a significant piezoelectric activity at the nanoscale, which is promising for their use as transducer elements in nanoelectromechanical systems (NEMS). PMID:17186911

Ricote, Jesús; Holgado, Susana; Ramos, Pablo; Calzada, M Lourdes

2006-12-01

74

Compact piezoelectric micromotor with a single bulk lead zirconate titanate stator  

NASA Astrophysics Data System (ADS)

The advance of micro/nanotechnology promotes the development of micromotors in recent years. In this article, a compact piezoelectric ultrasonic micromotor with a single bulk lead zirconate titanate stator is proposed. A traveling wave is generated by superposition of bending modes with 90° phase difference excited by d15 inverse piezoelectric effects. The operating principle simplifies the system structure significantly, and provides a miniaturization solution. A research prototype with the size of 0.75× 0.75×1.55 mm is developed. It can produce start-up torque of 0.27?Nmand maximum speed of 2760 r/min at 14RMS.

Yan, Liang; Lan, Hua; Jiao, Zongxia; Chen, Chin-Yin; Chen, I.-Ming

2013-04-01

75

Local and global energy release rates for an electrically yielded crack in a piezoelectric ceramic  

Microsoft Academic Search

Structural reliability concerns of various electromechanical devices call for a better understanding of the mechanisms of fracture in piezoelectric ceramics subjected to combined mechanical and electrical loading. For these materials, due to unexplained discrepancies between theory and experiments, even the basic criterion of fracture remains a point of controversy. A viewpoint adopted in this paper is to model piezoelectric ceramics

Huajian Gao; Tong-Yi Zhang; Pin Tong

1997-01-01

76

Piezoelectric and Magnetoelectric Properties of Lead Zirconate Titanate\\/Ni-Ferrite Particulate Composites  

Microsoft Academic Search

Piezoelectric and magnetoelectric properties of magnetoelectric particulate composites with Lead Zirconate Titanate (PZT) and Ni-ferrite were investigated. The maximum magnetoelectric voltage coefficient, (dE\\/dH)max, increased with higher sintering temperature up to 1250 ? C. Composites sintered at 1300 ? C, had dis- solution of Fe ions into PZT, or interdiffusion between PZT and ferrite. Connectivity of the ferrite particles and sintering

JUNGHO RYU; ALFREDO V ´ AZQUEZ CARAZO; KENJI UCHINO; HYOUN-EE KIM

2001-01-01

77

Fabrication of piezoelectric ceramic micro-actuator and its reliability for hard disk drives  

Microsoft Academic Search

A new U-type micro-actuator for precisely positioning a magnetic head in high-density hard disk drives was proposed and developed. The micro-actuator is composed of a U-type stainless steel substrate and two piezoelectric ceramic elements. Using a high-d31 piezoelectric coefficient PMN-PZT ceramic plate and adopting reactive ion etching process fabricate the piezoelectric elements. Reliability against temperature was investigated to ensure the

Yang Jing; Jianbin Luo; Wenyan Yang; Guoxian Ju

2004-01-01

78

Measurement of Micro Vibration of Car by Piezoelectric Ceramics  

NASA Astrophysics Data System (ADS)

Recently, there are various accidents and crimes related to the car. In some cases, the accidents and the crimes can be prevented if it is possible to detect a human who is in the car. For example, we can prevent a baby who is left in a car under the hot weather from dehydration or death occurred by heat inside disease. In another case, it is estimated that the United States currently has as many as 12 million illegal immigrants. In order to prevent further influx of illegal immigrants, the police are physically searching incoming vehicles at national boundaries aiming at finding those who are hiding inside. However, the physical inspections require much manpower cost and time. An inspection method to see inside the vehicles through X-ray images has also been used for this end. But the cost and the installation places are the problems of the large-scale X-ray system. Proposed in this paper is a piezoelectric ceramic system to handily measure the micro vibrations of motor vehicles. And applying the algorithm of Support Vector Machine (SVM), the existence of human body inside vehicles can be detected. The experiment was carried out using four types of vehicles: a mini car; an auto mobile; a van; and a truck weighing 1.5 tons. As the results, the correct determination ratio was 91.2% for the experiment with the piezoelectric ceramic under the front wheels and 97.0% under the rear wheels, when the vehicle used for the examination had also been used together with other three types of vehicles to obtain SVM training data. When the vehicle used for the examination had not been used together with the other three to obtain SVM training data, on the other hand, the correct determination ratio was 93.7% for the experiment with the piezoelectric ceramic under the front wheels and 95.7% under the rear wheels.

Kurihara, Yosuke; Masuyama, Kosuke; Nakamura, Testuo; Bamba, Takeshi; Watanabe, Kajiro

79

Low temperature piezoelectric and dielectric properties of lead magnesium niobate titanate single crystals  

NASA Astrophysics Data System (ADS)

Lead magnesium niobate-lead titanate (PMN-xPT) single crystal plates were prepared close to the morphotropic phase boundary with PT compositions 27%-31%. The piezoelectric and dielectric properties of these plates at liquid-helium temperature (4.2 K) were obtained by fitting measured impedance curves. In particular, the piezoelectric strain constant e33 is found to be in the range of 5.1-5.7 C m-2 at 4.2 K, which indicates an extraordinarily large piezoelectric effect compared with other materials even at such a low temperature. This result shows that PMN-xPT single crystals are promising candidates for ultrasonic transducers at low temperatures.

Guo, Wei; Jin, Dafei; Wei, Wanchun; Maris, Humphrey J.; Tian, Jian; Huang, Xingling; Han, Pengdi

2007-10-01

80

Electrical power generation characteristics of PZT piezoelectric ceramics.  

PubMed

The electrical power generation characteristics of Mn-doped PZT ceramics responding to slow mechanical stress as well as to impact stress have been investigated. Although both the slow and impact stresses induce a reversible electrical response, the generation properties are distinctly different. Slow stress releases two output current peaks with opposite directions, responding to the increasing and decreasing part of the stress, respectively. However, impact stress produces a nearly one-directional signal. The output charge and energy by slow stress are found to be two orders of magnitude higher than that produced by impact stress. This work shows that the energy conversion efficiency of piezoelectric ceramics strongly depends on the method of stress application. PMID:18244261

Xu, C N; Akiyama, M; Nonaka, K; Watanabe, T

1998-01-01

81

Stereolithography of lead zirconate titanate ceramics for MEMS applications  

NASA Astrophysics Data System (ADS)

In this study, stereolithography of PZT films or composites has been successfully carried out. With regard to the PZT suspensions formulation, the process was modified to allow the deposition of films with thickness ranging between 8 to 40 ?m. 1-3 and 0-3 piezocomposites as well as other highly loaded structures (maximum 45 % in volume) have been elaborated. Moreover, PZT thick films have been deposited on metallic substrates and silicon wafers. After sintering, crack-free PZT films with thickness ranging between 12 to hundreds of microns have been metallized and polarized. The properties of these microstructures have been studied with permittivity and piezoelectric coefficients measurements. Experiments have shown that the piezoelectric properties of PZT ceramics fabricated by stereolithography are promising (d33 up to 200 pC/N and g33 greater than 30×10-3 Vm/N), which implies that such structures could be integrated in MEMS for microactuators or sensors applications. Finally, simultaneous fabrications by conventional stereolithography of polymer micropumps and their related piezoelectric transducers have been tested. The upper polymer member of the micropump is 100 ?m thick and the inner diameter of the pump is 5 mm. Researches are in progress to improve the micropump flow rate and to manufacture a drop-on-demand inkjet device.

Dufaud, Olivier; Le Gall, Herve; Corbel, Serge

2003-04-01

82

Microstructure, electrical conductivity, and piezoelectric properties of bismuth titanate  

Microsoft Academic Search

A study was conducted on the effects of microstructure, atmosphere, and several dopants on the electrical conductivity of bismuth titanate (BiâTiâOââ, BIT). Increased grain size increased the conductivity in undoped BIT as did acceptor dopants that substituted for either Bi (Ca and Sr) or Ti(Fe). A donor dopant (Nb) decreased the conductivity in BIT by as much as 3 orders

Holly S. Shulman; Martin Testorf; Dragan Damjanovic; Nava Setter

1996-01-01

83

Determination of the piezoelectric coefficients d ij of PZT ceramics and composites by laser interferometry  

Microsoft Academic Search

We have measured the piezoelectric coefficients of PZT ceramics by resonance and laser interferometry methods. The surface displacement was measured by a single-beam Michelson interferometer. A stable double-beam interferometer was also used to suppress the effect of bending. The piezoelectric coefficients dij of the PZT ceramic and of the 0–3 ceramic–polymer composites were determined from the displacements. The results for

L Burianová; M Šulc; M Prokopová

2001-01-01

84

Converse mode piezoelectric coefficient for lead zirconate titanate thin film with interdigitated electrode  

NASA Astrophysics Data System (ADS)

The use of interdigitated electrodes (IDEs) in conjunction with ferroelectric thin films shows many attractive features for piezoelectric MEMS applications. In this work, growth of {1?0?0}-textured lead zirconate titanate (PZT) thin films was achieved on insulating MgO buffered, oxidized silicon substrates. IDEs were fabricated by lift-off techniques and cantilevers were formed by dicing. The deflection upon application of a sweeping voltage was measured as large signal response in parallel to the ferroelectric polarization (PV loop). Likewise, the small signal piezoelectric response was measured in parallel to the capacitance-voltage (CV) measurement. In this way, a complete picture of the ferroelectric–piezoelectric element was obtained. From the deflection, the in-plane piezoelectric stress in the PZT thin film was derived and, from this, the effective piezoelectric coefficients. For the latter, two types were defined: an engineering type corresponding to the average value along the IDE, which can directly be compared to coefficient of a parallel plate electrode (PPE) capacitor and a second one that approximately yields the idealized coefficient governing between the electrode fingers. The IDE structures were experimentally compared with PPE structures of identical film thickness. The resulting coefficients were of opposite sign, as expected. In spite of a much better polarization loop, the IDE device showed a lower average piezoelectric stress. The estimated peak value between the fingers was about the same as in the PPE device, corresponding to about 20 C m?2. Nevertheless, the result is very promising for cases where compressive piezoelectric stresses are required and for preventing cracking due to large piezoelectric tensile stresses in PPE systems.

Chidambaram, N.; Balma, D.; Nigon, R.; Mazzalai, A.; Matloub, R.; Sandu, C. S.; Muralt, P.

2015-04-01

85

Tailoring of unipolar strain in lead-free piezoelectrics using the ceramic/ceramic composite approach  

SciTech Connect

The electric-field-induced strain response mechanism in a polycrystalline ceramic/ceramic composite of relaxor and ferroelectric materials has been studied using in situ high-energy x-ray diffraction. The addition of ferroelectric phase material in the relaxor matrix has produced a system where a small volume fraction behaves independently of the bulk under an applied electric field. Inter- and intra-grain models of the strain mechanism in the composite material consistent with the diffraction data have been proposed. The results show that such ceramic/ceramic composite microstructure has the potential for tailoring properties of future piezoelectric materials over a wider range than is possible in uniform compositions.

Khansur, Neamul H.; Daniels, John E. [School of Materials Science and Engineering, University of New South Wales, NSW 2052 (Australia); Groh, Claudia; Jo, Wook; Webber, Kyle G. [Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Reinhard, Christina [Diamond Light Source, Beamline I12 JEEP, Didcot, Oxfordshire OX11 0DE (United Kingdom); Kimpton, Justin A. [The Australian Synchrotron, Clayton, Victoria 3168 (Australia)

2014-03-28

86

Tailoring of unipolar strain in lead-free piezoelectrics using the ceramic/ceramic composite approach  

NASA Astrophysics Data System (ADS)

The electric-field-induced strain response mechanism in a polycrystalline ceramic/ceramic composite of relaxor and ferroelectric materials has been studied using in situ high-energy x-ray diffraction. The addition of ferroelectric phase material in the relaxor matrix has produced a system where a small volume fraction behaves independently of the bulk under an applied electric field. Inter- and intra-grain models of the strain mechanism in the composite material consistent with the diffraction data have been proposed. The results show that such ceramic/ceramic composite microstructure has the potential for tailoring properties of future piezoelectric materials over a wider range than is possible in uniform compositions.

Khansur, Neamul H.; Groh, Claudia; Jo, Wook; Reinhard, Christina; Kimpton, Justin A.; Webber, Kyle G.; Daniels, John E.

2014-03-01

87

Electrical properties of lanthanum doped barium titanate ceramics  

SciTech Connect

Pure and lanthanum doped barium titanate (BT) ceramics were prepared by sintering pellets at 1300 deg. C for 8 h, obtained from nanopowders synthesized by the polymeric precursor method. XRD results showed formation of a tetragonal structure. The presence of dopants changed the tetragonal structure to pseudo-cubic. The polygonal grain size was reduced up to 300 nm with addition of lanthanum as a donor dopant. Determined dielectric properties revealed that lanthanum modified BT ceramics possessed a diffused ferroelectric character in comparison with pure BT that is a classical ferroelectric material. In doped BT phase transition temperatures were shifted to lower temperatures and dielectric constant values were much higher than in pure BT. A modified Currie Weiss law was used to explore the connection between the doping level and degree of diffuseness of phase transitions. Impedance spectroscopy measurements were carried out at different temperatures in order to investigate electrical resistivity of materials and appearance of a PTCR effect. - Highlights: {yields} Pure and lanthanum doped BaTiO{sub 3} were prepared by polymeric precursors method. {yields} Change of structure from tetragonal to pseudo-cubic. {yields} Lanthanum as a donor dopant influenced on change of ferro-para phase transition. {yields} The diffuseness factor indicated the formation of diffuse ferroelectric material. {yields} Lanthanum affected on PTCR effect appearance in BT ceramics.

Vijatovic Petrovic, M.M., E-mail: miravijat@yahoo.com [Institute for Multidisciplinary Research, Belgrade University, Kneza Viseslava 1, Belgrade (Serbia); Bobic, J.D. [Institute for Multidisciplinary Research, Belgrade University, Kneza Viseslava 1, Belgrade (Serbia); Ramoska, T.; Banys, J. [Faculty of Physics, Vilnius University, Sauletekio al. 9, Vilnius (Lithuania); Stojanovic, B.D. [Institute for Multidisciplinary Research, Belgrade University, Kneza Viseslava 1, Belgrade (Serbia)

2011-10-15

88

Experiments to Demonstrate Piezoelectric and Pyroelectric Effects  

ERIC Educational Resources Information Center

Piezoelectric and pyroelectric materials are used in many current applications. The purpose of this paper is to explain the basic properties of pyroelectric and piezoelectric effects and demonstrate them in simple experiments. Pyroelectricity is presented on lead zirconium titanate (PZT) ceramics as an electric charge generated by the temperature…

Erhart, Jirí

2013-01-01

89

Aligned porous barium titanate/hydroxyapatite composites with high piezoelectric coefficients for bone tissue engineering.  

PubMed

It was proposed that the piezoelectric effect played an important physiological role in bone growth, remodelling and fracture healing. An aligned porous piezoelectric composite scaffold was fabricated by freeze casting hydroxyapatite/barium titanate (HA/BT) suspensions. The highest compressive strength and lowest porosity of 14.5MPa and 57.4% with the best parallelism of the pore channels were achieved in the HA10/BT90 composite. HA30/BT70 and HA10/BT90 composites exhibited piezoelectric coefficient d33 of 1.2 and 2.8pC/N, respectively, both of which were higher than the piezoelectric coefficient of natural bone. Increase of the solid loading of the suspension and solidification velocity led to the improvement of piezoelectric coefficient d33. Meanwhile, double-templates resulted in the coexistence of lamellar pores and aligned macro-pores, exhibiting the ability to produce an oriented long-range ordered architecture. The manipulation flexibility of this method indicated the potential for customized needs in the application of bone substitute. An MTT assay indicated that the obtained scaffolds had no cytotoxic effects on L929 cells. PMID:24863210

Zhang, Yan; Chen, Liangjian; Zeng, Jing; Zhou, Kechao; Zhang, Dou

2014-06-01

90

Tunability and relaxor properties of ferroelectric barium stannate titanate ceramics  

SciTech Connect

Barium stannate titanate [Ba(Sn{sub x}Ti{sub 1-x})O{sub 3}, x=0.1, 0.2, 0.3, and 0.4] ceramics were prepared using a conventional solid-state reaction process. Their dielectric properties were measured under direct current bias fields ranging from 0 to 2.5 kV/cm. A transformation from normal to relaxor ferroelectrics was observed when x{>=}0.3. Broken long-range order or 'dirty' ferroelectric domains and nanodomains were observed in Ba(Sn{sub 0.1}Ti{sub 0.9})O{sub 3} and Ba(Sn{sub 0.4}Ti{sub 0.6})O{sub 3} by transmission electron microscopy, respectively. Voltage driven tunability was found to decrease with increasing Sn content. The change from normal ferroelectric into relaxor ferroelectric had a negative impact on the tunability value of the materials.

Lu, S.G.; Xu, Z.K.; Chen, Haydn [Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong (China)

2004-11-29

91

Porosity Dependence of Piezoelectric Properties for Porous Potassium Niobate System Ceramics  

NASA Astrophysics Data System (ADS)

Porous potassium niobate (KNbO3, KN) system ceramics were prepared by a conventional sintering method using carbon black (CB) nanoparticles. First, KN nanoparticles with a size of 100 nm was mixed with CB nanoparticles and binder using ball milling with ethanol. The mixture was dried, and pressed into pellets using uniaxial pressing. After binder burnout, these ceramics was sintered in air. Their piezoelectric properties were measured and discussed a relationship between porosity and piezoelectric properties. As the results, with increasing porosity, piezoelectric g33 constant increased significantly, which suggested that porous ceramics were effective for stress sensor application.

Wada, S.; Mase, Y.; Shimizu, S.; Maeda, K.; Fujii, I.; Nakashima, K.; Pulpan, P.; Miyajima, N.

2011-10-01

92

Electrical properties of niobium doped barium bismuth-titanate ceramics  

SciTech Connect

Highlights: ? Pure and doped BaBi{sub 4}Ti{sub 4}O{sub 15} were prepared via the solid-state reaction method. ? The grain size was suppressed in Nb-doped samples. ? The diffuseness of the dielectric peak increased with dopant concentration. ? Niobium affected on relaxor behavior of barium bismuth titanate ceramics. ? The conductivity change was noticed in doped samples. -- Abstract: BaBi{sub 4}Ti{sub 4–5/4x}Nb{sub x}O{sub 15} (BBNTx, x = 0, 0.05, 0.15, 0.30) ceramics have been prepared by solid state method. XRD data indicate the formation of single-phase-layered perovskites for all compositions. SEM micrographs suggest that the grain size decreases with Nb doping. The effect of niobium doping on the dielectric and relaxor behavior of BaBi{sub 4}Ti{sub 4}O{sub 15} ceramics was investigated in a wide range of temperatures (20–777 °C) and frequencies (1.21 kHz to 1 MHz). Nb doping influences T{sub c} decrease as well as the decrease of dielectric permittivity at Curie temperature. At room temperature, undoped BaBi{sub 4}Ti{sub 4}O{sub 15} exhibits dielectric constant of ?204 at 100 kHz, that slightly increases with Nb doping. The conductivity of BBNT5 ceramics is found to be lower than that of other investigated compositions. The value of activation energy of ?{sub DC} was found to be 0.89 eV, 1.01 eV, 0.93 eV and 0.71 eV for BBT, BBNT5, BBNT15 and BBNT30, respectively.

Bobi?, J.D., E-mail: jelenabobic@yahoo.com [Institute for Multidisciplinary Researches, Belgrade University, Kneza Viseslava 1, Belgrade (Serbia); Vijatovi? Petrovi?, M.M. [Institute for Multidisciplinary Researches, Belgrade University, Kneza Viseslava 1, Belgrade (Serbia)] [Institute for Multidisciplinary Researches, Belgrade University, Kneza Viseslava 1, Belgrade (Serbia); Banys, J. [Faculty of Physics, Vilnius University, 9 Sauletekio Str., Vilnius (Lithuania)] [Faculty of Physics, Vilnius University, 9 Sauletekio Str., Vilnius (Lithuania); Stojanovi?, B.D. [Institute for Multidisciplinary Researches, Belgrade University, Kneza Viseslava 1, Belgrade (Serbia)] [Institute for Multidisciplinary Researches, Belgrade University, Kneza Viseslava 1, Belgrade (Serbia)

2012-08-15

93

Three-dimensional ceramic molding process based on microstereolithography for the production of piezoelectric energy harvesters  

NASA Astrophysics Data System (ADS)

A three-dimensional (3-D) molding process using a master polymer mold produced by microstereolithography has been developed for the production of piezoelectric ceramic elements. In this method, ceramic slurry is injected into a 3-D polymer mold via a centrifugal casting process. The polymer master mold is thermally decomposed so that complex 3-D piezoelectric ceramic elements can be produced. As an example of 3-D piezoelectric ceramic elements, we produced a spiral piezoelectric element that can convert multidirectional loads into a voltage. It was confirmed that a prototype of the spiral piezoelectric element could generate a voltage by applying a load in both parallel and lateral directions in relation to the helical axis. The power output of 123 pW was obtained by applying the maximum load of 2.8N at 2 Hz along the helical axis. In addition, to improve the performance of power generation, we utilized a two-step sintering process to obtain dense piezoelectric elements. As a result, we obtained a sintering body with relative density of 92.8%. Piezoelectric constant d31 of the sintered body attained to -40.0 pC/N. Furthermore we analyzed the open-circuit voltage of the spiral piezoelectric element using COMSOL multiphysics. As a result, it was found that use of patterned electrodes according to the surface potential distribution of the spiral piezoelectric element had a potential to provide high output voltage that was 20 times larger than that of uniform electrodes.

Maruo, Shoji; Sugiyama, Kenji; Daicho, Yuya; Monri, Kensaku

2014-03-01

94

Solvothermal preparation of potassium niobate/barium titanate nanocomplex ceramics with three dimensional network-configuration of structure-gradient region and their dielectric properties  

NASA Astrophysics Data System (ADS)

To improve dielectric properties of barium titanate (BaTiO3, BT)-based ceramics, the BT/potassium niobate (KNbO3, KN) nanocomplex ceramics were designed to expect the formation of a three dimensional network-configuration of a structure-gradient region (SGR), where the polar vector can easily rotate. The KN epitaxial nanolayers were formed on BT compacts with a necking structure by a solvothermal method and the maximal dielectric constant of 1450 and the relatively large apparent piezoelectric constant d33* of 318 pm/V were recorded for the KN/BT nanocomplex ceramics. The experimental facts suggest that the configuration of the SGR, in addition to the relative density, is one of the important factors to enhance the dielectric properties of the KN/BT nanocomplex ceramics.

Ueno, S.; Kawashima, H.; Nakashima, K.; Kumada, N.; Magome, E.; Moriyoshi, C.; Kuroiwa, Y.; Fujikawa, Y.; Tanaka, D.; Furukawa, M.; Wada, S.

2013-08-01

95

Theoretical study on the static performance of piezoelectric ceramic-polymer composites with 1-3 connectivity  

E-print Network

Theoretical study on the static performance of piezoelectric ceramic- polymer composites with 1 1992) Inhomogeneous displacement profiles have been derived for a single-rod composite and a single piezoelectric constants for the composites have been derived in terms of the ceramic content, the piezoelectric

Cao, Wenwu

96

Optimization of a piezoelectric bimorph grasper for use in minimally invasive surgical applications  

E-print Network

-zirconate (PbZrO3), and barium-titanate (BaTiO3) have been known to exhibit a piezoelectric effect. In addition'. Several ceramic materials such as lead-zirconate-titanate (PZT), lead-titanate (PbTiO2), lead

Grujicic, Mica

97

Conformable amplified lead zirconate titanate sensors with enhanced piezoelectric response for cutaneous pressure monitoring  

NASA Astrophysics Data System (ADS)

The ability to measure subtle changes in arterial pressure using devices mounted on the skin can be valuable for monitoring vital signs in emergency care, detecting the early onset of cardiovascular disease and continuously assessing health status. Conventional technologies are well suited for use in traditional clinical settings, but cannot be easily adapted for sustained use during daily activities. Here we introduce a conformal device that avoids these limitations. Ultrathin inorganic piezoelectric and semiconductor materials on elastomer substrates enable amplified, low hysteresis measurements of pressure on the skin, with high levels of sensitivity (~0.005?Pa) and fast response times (~0.1?ms). Experimental and theoretical studies reveal enhanced piezoelectric responses in lead zirconate titanate that follow from integration on soft supports as well as engineering behaviours of the associated devices. Calibrated measurements of pressure variations of blood flow in near-surface arteries demonstrate capabilities for measuring radial artery augmentation index and pulse pressure velocity.

Dagdeviren, Canan; Su, Yewang; Joe, Pauline; Yona, Raissa; Liu, Yuhao; Kim, Yun-Soung; Huang, Yongan; Damadoran, Anoop R.; Xia, Jing; Martin, Lane W.; Huang, Yonggang; Rogers, John A.

2014-08-01

98

Conformable amplified lead zirconate titanate sensors with enhanced piezoelectric response for cutaneous pressure monitoring.  

PubMed

The ability to measure subtle changes in arterial pressure using devices mounted on the skin can be valuable for monitoring vital signs in emergency care, detecting the early onset of cardiovascular disease and continuously assessing health status. Conventional technologies are well suited for use in traditional clinical settings, but cannot be easily adapted for sustained use during daily activities. Here we introduce a conformal device that avoids these limitations. Ultrathin inorganic piezoelectric and semiconductor materials on elastomer substrates enable amplified, low hysteresis measurements of pressure on the skin, with high levels of sensitivity (~0.005?Pa) and fast response times (~0.1?ms). Experimental and theoretical studies reveal enhanced piezoelectric responses in lead zirconate titanate that follow from integration on soft supports as well as engineering behaviours of the associated devices. Calibrated measurements of pressure variations of blood flow in near-surface arteries demonstrate capabilities for measuring radial artery augmentation index and pulse pressure velocity. PMID:25092496

Dagdeviren, Canan; Su, Yewang; Joe, Pauline; Yona, Raissa; Liu, Yuhao; Kim, Yun-Soung; Huang, YongAn; Damadoran, Anoop R; Xia, Jing; Martin, Lane W; Huang, Yonggang; Rogers, John A

2014-01-01

99

Detection of high-energy heavy ions using piezoelectric lead zirconate titanate  

SciTech Connect

The characteristics of a radiation detector fabricated with stacks of piezoelectric lead zirconate titanate (PZT) elements were studied by irradiating it with a 400 MeV/n xenon (Xe) beam for various beam pulse durations. This detector is referred to as the multilayered detector (MD). To understand the production mechanism behind the output voltage obtained from the MD, measurement of the spatial distribution of the output signals generated in the MD was attempted. It was found that the amplitude observed was dependent on the number of Xe ions per unit time and the amount of ionization loss energy of Xe ions in PZT.

Takechi, Seiji; Morinaga, Shin-ya; Kurozumi, Atsuma [Graduate School of Engineering, Osaka City University, Osaka 558-8585 (Japan); Miyachi, Takashi; Fujii, Masayuki; Hasebe, Nobuyuki [Advanced Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555 (Japan); Shibata, Hiromi [Graduate School of Engineering, Kyoto University, Kyoto 606-8501 (Japan); Murakami, Takeshi; Uchihori, Yukio [National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Okada, Nagaya [Honda Electronics Co., Ltd., Aichi 441-3193 (Japan)

2009-04-15

100

Measurement of incident position of hypervelocity particles on piezoelectric lead zirconate titanate detector  

SciTech Connect

A cosmic dust detector for use onboard a satellite is currently being developed by using piezoelectric lead zirconate titanate (PZT). The characteristics of the PZT detector have been studied by bombarding it with hypervelocity iron (Fe) particles supplied by a Van de Graaff accelerator. One central electrode and four peripheral electrodes were placed on the front surface of the PZT detector to measure the impact positions of the incident Fe particles. It was demonstrated that the point of impact on the PZT detector could be identified by using information on the time at which the first peak of the output signal obtained from each electrode appeared.

Takechi, Seiji; Onishi, Toshiyuki; Minami, Shigeyuki [Graduate School of Engineering, Osaka City University, Osaka 558-8585 (Japan); Miyachi, Takashi; Fujii, Masayuki; Hasebe, Nobuyuki [Advanced Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555 (Japan); Nogami, Ken-ichi [Department of Physics, Dokkyo University School of Medicine, Tochigi 321-0293 (Japan); Ohashi, Hideo [Faculty of Marine Science, Tokyo University of Marine Science and Technology, Tokyo 108-8477 (Japan); Sasaki, Sho [National Astronomical Observatory of Japan, Iwate 023-0861 (Japan); Shibata, Hiromi [Graduate School of Engineering, Kyoto University, Kyoto 606-8501 (Japan); Iwai, Takeo [Research Center for Nuclear Science and Technology, The University of Tokyo, Ibaraki 319-1106 (Japan); Gruen, Eberhard; Srama, Ralf [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Okada, Nagaya [Honda Electronics Co., Ltd., Aichi 441-3193 (Japan)

2008-04-15

101

Overview of NASA Langley's Piezoelectric Ceramic Packaging Technology and Applications  

NASA Technical Reports Server (NTRS)

Over the past decade, NASA Langley Research Center (LaRC) has developed several actuator packaging concepts designed to enhance the performance of commercial electroactive ceramics. NASA LaRC focused on properly designed actuator and sensor packaging for the following reasons, increased durability, protect the working material from the environment, allow for proper mechanical and electrical contact, afford "ready to use" mechanisms that are scalable, and develop fabrication methodology applicable to any active material of the same physical class. It is more cost effective to enhance or tailor the performance of existing systems, through innovative packaging, than to develop, test and manufacture new materials. This approach led to the development of several solid state actuators that include THUNDER, the Macrofiber Composite or (MFC) and the Radial Field Diaphragm or (RFD). All these actuators are fabricated using standard materials and processes derived from earlier concepts. NASA s fabrication and packaging technology as yielded, piezoelectric actuators and sensors that are easy to implement, reliable, consistent in properties, and of lower cost to manufacture in quantity, than their predecessors (as evidenced by their continued commercial availability.) These piezoelectric actuators have helped foster new research and development in areas involving computational modeling, actuator specific refinements, and engineering system redesign which led to new applications for piezo-based devices that replace traditional systems currently in use.

Bryant, Robert G.

2007-01-01

102

Optical Measurement of Piezoelectric Vibration in Circular Rod and Disk Ceramics  

Microsoft Academic Search

The fiber-optic measurement and evaluation of piezoelectric vibration of circular rod and disk ceramics are described. The values corresponding to the piezoelectric d- and g-constants can be obtained locally by measuring amplitude and Q-value at the first-resonance frequency under appropriate electric conditions. The results are analyzed numerically by using the theory of coupled resonance.

Michio Ohki; Naomi Shima; Tadashi Shiosaki

1992-01-01

103

Residual stress development and effect on the piezoelectric performance of sol-gel derived lead zirconate titanate (PZT) thin films  

NASA Astrophysics Data System (ADS)

Ferroelectric thin films have higher energy densities, larger strain capabilities and more rapid response times than their bulk counterparts. Typical applications include micro-actuators, micro-sensors and ultrasonic motors for MEMs applications, as well as, nonvolatile computer memories and switching capacitors for integrated circuitry. The electro-mechanical performance of ceramic thin films is greatly influenced by many factors, including grain size, orientation, film thickness, and residual stress level. Residual stresses which arise during the various processing phases of thin film manufacturing can be quite high due to substantial mismatches in substrate-film thermal properties, intrinsic sources (such as grain boundary interactions, etc.), and other external factors. This dissertation examines the relationship between field-induced displacement response and residual stress level for lead zirconate-titanate (PZT) thin films. The film piezoelectric properties are characterized via interferometric measurements for two different loading cases, while the residual stress is determined experimentally from wafer curvature measurements. Additionally two patterning methods, traditional chemical wet-etching and a novel soft lithographic technique, are explored as a means to reduce residual stress within film features. For the soft lithographic technique, film features are created by selective film cracking, a result of poor substrate adhesion promoted by a mediated, self-assembled monolayer. Wafer curvature stress measurements and DIC-based strain measurements of mediated monolayer patterned features reveal that the in-plane stress/strain development is reduced compared to the blanket film case. Critical in-plane strains at crack initiation are also measured using a new digital image correlation technique, in which fluorescent nanoparticles (c.a. 140 nm) provide the speckle pattern. A corresponding increase in the field induced displacements is observed for the film features with reduced residual stress. Overall, the piezoelectric performance of the films is highly dependent on the residual stress in the films and can be enhanced significantly by a reduction in this stress through film patterning.

Berfield, Thomas A.

104

A piezoelectric active mirror suspension system embedded into low-temperature cofired ceramic.  

PubMed

Low-temperature cofired ceramic (LTCC) has proven to be a cost-effective, flexible technology for producing complicated structures such as sensors, actuators, and microsystems. This paper presents a piezoelectric active mirror suspension system embedded into LTCC. In the structure, the LTCC was used as a package, for the passive layers of piezoelectric monomorphs, as support for the mirrors, and as a substrate for the conductors. The active mirror structure, 17 mm in diameter, was made by compiling 20 LTCC layers using common LTCC processing techniques. Each sample contained a laser-micromachined bulk lead zirconate titanate (PZT) structure which formed a monomorph with the LTCC during the firing process. A mirror substrate (diameter 4 mm) was mounted in the middle of the monomorph arms for evaluation of the positioning performance, where each of the three arms had independent signal electrodes and a common ground electrode. Electrical and electromechanical properties were investigated with an LCR meter, network analyzer, and laser vibrometer for the different arms and the mirror. The active mirror structure exhibited more than 1 ?m dc displacement for mirror leveling and also allowed small changes in mirror angle up to 0.06°. The first bending resonance frequency of the structure with the mirror was detected at 11.31 kHz with 4.0 ?m displacement; 13.02 kHz and 2.7 ?m were obtained without the mirror. The structure exhibited characteristics feasible for further utilization in tunable Fabry-Perot filter applications, allowing the mounting of active mirrors on both sides with distance and angle control. PMID:23007772

Sobocinski, Maciej; Leinonen, Mikko; Juuti, Jari; Jantunen, Heli

2012-09-01

105

Functional microwave flat antenna using alumina ceramic substrate and piezoelectric actuator  

Microsoft Academic Search

We have demonstrated a new-type microstrip patch antenna on a dielectric ceramic substrate with a mechanism of a variable antenna height using a mechatronics technology. The functional microwave flat antenna with an alumina ceramic substrate was controlled by a piezoelectric actuator, and changed the resonant frequencies. We have confirmed a possible variation of the antenna resonant frequency of 96% from

Kazuhiro Kitatani; Yuichi Sakaguchi; Yasuyuki Okamura

2006-01-01

106

Effect of crystallographic orientation in textured Ba0.92Ca0.08TiO3 piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

Strongly textured lead-free Ba0.92Ca0.08TiO3 piezoelectric ceramics were fabricated by tape casting and templated grain growth. Dense ceramics with both favorable ?100? and unfavorable ?111? texture were successfully prepared. Enhanced piezoelectric performance was demonstrated for ceramics with ?100? texture, in line with the predictions based on reported piezoelectric coefficients of tetragonal BaTiO3. Due to the expanded tetragonal range through Ca-substitution, ?100? texture is favorable over a wide temperature range. The ?100? texture also results in the enhanced piezoelectric performance being temperature-independent. In addition to engineering of stable, high-performance lead-free piezoelectric ceramics, this study has demonstrated that consideration of the extender/rotator nature of piezoelectric properties is imperative for improving the piezoelectric response through texturing.

Haugen, Astri Bjørnetun; Morozov, Maxim I.; Johnsson, Mats; Grande, Tor; Einarsrud, Mari-Ann

2014-10-01

107

Using Piezoelectric Ceramics for Dust Mitigation of Space Suits  

NASA Technical Reports Server (NTRS)

The particles that make up moon dust and Mars soil can be hazardous to an astronaut s health if not handled properly. In the near future, while exploring outer space, astronauts plan to wander the surfaces of unknown planets. During these explorations, dust and soil will cling to their space suits and become imbedded in the fabric. The astronauts will track moon dust and mars soil back into their living quarters. This not only will create a mess with millions of tiny air-born particles floating around, but will also be dangerous in the case that the fine particles are breathed in and become trapped in an astronaut s lungs. research center are investigating ways to remove these particles from space suits. This problem is very difficult due to the nature of the particles: They are extremely small and have jagged edges which can easily latch onto the fibers of the fabric. For the past summer, I have been involved in researching the potential problems, investigating ways to remove the particles, and conducting experiments to validate the techniques. The current technique under investigation uses piezoelectric ceramics imbedded in the fabric that vibrate and shake the particles free. The particles will be left on the planet s surface or collected a vacuum to be disposed of later. The ceramics vibrate when connected to an AC voltage supply and create a small scale motion similar to what people use at the beach to shake sand off of a beach towel. Because the particles are so small, similar to volcanic ash, caution must be taken to make sure that this technique does not further inbed them in the fabric and make removal more difficult. Only a very precise range of frequency and voltage will produce a suitable vibration. My summer project involved many experiments to determine the correct range. Analysis involved hands on experience with oscilloscopes, amplifiers, piezoelectrics, a high speed camera, microscopes and computers. perfect this technology. Someday, vibration to remove dust may a vital component to the space exploration program. In order to mitigate this problem, engineers and scientists at the NASA-Glenn Further research and experiments are planned to better understand and ultimately

Angel, Heather K.

2004-01-01

108

A novel approach to electrochromism in WO3 thin film using piezoelectric ceramics for power supply  

NASA Astrophysics Data System (ADS)

Electrochromism was newly realized in a WO3-Pb(Zroverflow="scroll">0.52Ti0.48)Ooverflow="scroll">3 (PZT) system which utilized the piezoelectric property of PZT ceramics for power supply. The electric power produced by Mn-doped PZT ceramics enabled the WO3 film to color blue. High piezoelectricity with a peak voltage of 35 V and peak current of 1.2 mA on a 30 k? circuit was observed at a pressure of 30 MPa for the present system. This study shows the possibility to actuate the electrochromic WO3 film with PZT ceramics.

Xu, C. N.; Akiyama, M.; Sun, P.; Watanabe, T.

1997-03-01

109

Piezoelectric Properties of Grain-Oriented Bismuth Layer-Structured Ferroelectric Ceramics  

Microsoft Academic Search

Piezoelectric properties of grain-oriented bismuth layer-structured ferroelectric (BLSF) ceramics, such as Bi4,xPbxTi3,xNbx0~2 (BPTN) and Pbl,x(NaBi)x\\/2Bi4Ti40i5 (PNBT) prepared by the hot-forging (H.F.) method, are studied from the viewpoint of grain orientation. The grain orientation (H.F.) makes the piezoelectric properties of BLSF ceramics much more pronounced than those of non-oriented (O.F.) ceramics. The crystal symmetry of the poled H.F. BLSF piezoceramics appears

Tadashi TAKENAKA; Koichiro SAKATA

1986-01-01

110

Bi4Ti3O12-based lead-free piezoelectric ceramics with grain orientation  

Microsoft Academic Search

Piezoelectric properties of Bi4Ti3-xNbxO12 [BITN-x] and B4Ti3-xVxO12 [BITV-x] ceramics are investigated. Furthermore, grain orientation effects of BITN and BITV ceramics on their piezoelectric properties are studied using the hot-forging (HF) method. The optimal sintering temperature of the BITV ceramic becomes lower with increasing the amount of doped-V ions. On the ordinarily fired (OF) sample with a random orientation, an electromechanical

H. Nagata; Y. Fujita; H. Enosawa; T. Takenaka

2002-01-01

111

Piezoelectric nonlinearity and frequency dispersion of the direct piezoelectric response of BiFeO3 ceramics  

NASA Astrophysics Data System (ADS)

We report on the frequency and stress dependence of the direct piezoelectric d33 coefficient in BiFeO3 ceramics. The measurements reveal considerable piezoelectric nonlinearity, i.e., dependence of d33 on the amplitude of the dynamic stress. The nonlinear response suggests a large irreversible contribution of non-180° domain walls to the piezoelectric response of the ferrite, which, at present measurement conditions, reached a maximum of 38% of the total measured d33. In agreement with this interpretation, both types of non-180° domain walls, characteristic for the rhombohedral BiFeO3, i.e., 71° and 109°, were identified in the poled ceramics using transmission electron microscopy. In support to the link between nonlinearity and non-180° domain-wall contribution, we found a correlation between nonlinearity and processes leading to depinning of domain walls from defects, such as quenching from above the Curie temperature and high-temperature sintering. In addition, the nonlinear piezoelectric response of BiFeO3 showed a frequency dependence that is qualitatively different from that measured in other nonlinear ferroelectric ceramics, such as "soft" (donor-doped) Pb(Zr,Ti)O3 (PZT), i.e., in the case of the BiFeO3 large nonlinearities were observed only at low field frequencies (<0.1 Hz); possible origins of this dispersion are discussed. Finally, we show that, once released from pinning centers, the domain walls can contribute extensively to the electromechanical response of BiFeO3; in fact, the extrinsic domain-wall contribution is relatively as large as in Pb-based ferroelectric ceramics with morphotropic phase boundary (MPB) composition, such as PZT. This finding might be important in the search of new lead-free MPB compositions based on BiFeO3 as it suggests that such compositions might also exhibit large extrinsic domain-wall contribution to the piezoelectric response.

Rojac, Tadej; Bencan, Andreja; Drazic, Goran; Kosec, Marija; Damjanovic, Dragan

2012-09-01

112

Intelligent motion control for linear piezoelectric ceramic motor drive.  

PubMed

Since the dynamic characteristics of a linear piezoelectric ceramic motor (LPCM) are highly nonlinear and time varying, it is difficult to design a suitable motor drive and position controller that realizes accurate position control at all time. This study investigates a double-inductance double-capacitance (LLCC) resonant driving circuit and a sliding-mode fuzzy-neural-network control (SMFNNC) system for the motion control of an LPCM. First, the motor structure and LLCC driving circuit of an LPCM are introduced. The LLCC resonant inverter is designed to operate at an optimal switching frequency such that the output voltage will not be influenced by the variation of quality factor. Moreover, a SMFNNC system is designed to achieve favorable tracking performance without precise dynamic models being controlled. All adaptive learning algorithms in the SMFNNC system are derived in the sense of Lyapunov stability analysis, so that system-tracking stability can be guaranteed in the closed-loop system. The effectiveness of the proposed driving circuit and control system is verified by experimental results. PMID:15503505

Wai, Rong-Jong; Lee, Jeng-Dao

2004-10-01

113

Cement-based piezoelectric ceramic composites for sensor applications in civil engineering  

NASA Astrophysics Data System (ADS)

The objectives of this thesis are to develop and apply a new smart composite for the sensing and actuation application of civil engineering. Piezoelectric ceramic powder is incorporated into cement-based composite to achieve the sensing and actuation capability. The research investigates microstructure, polarization and aging, material properties and performance of cement-based piezoelectric ceramic composites both theoretically and experimentally. A hydrogen bonding is found at the interface of piezoelectric ceramic powder and cement phase by IR (Infrared Ray), XPS (X-ray Photoelectron Spectroscopy) and SIMS (Secondary Ion Mass Spectroscopy). It largely affects the material properties of composites. A simple first order model is introduced to explain the poling mechanism of composites and the dependency of polarization is discussed using electromechanical coupling coefficient kt. The mechanisms acting on the aging effect is explored in detail. Dielectrical, piezoelectric and mechanical properties of the cement-based piezoelectric ceramic composites are studied by experiment and theoretical calculation based on modified cube model (n=1) with chemical bonding . A complex circuit model is proposed to explain the unique feature of impedance spectra and the instinct of high-loss of cement-based piezoelectric ceramic composite. The sensing ability of cement-based piezoelectric ceramic composite has been evaluated by using step wave, sine wave, and random wave. It shows that the output of the composite can reflects the nature and characteristics of mechanical input. The work in this thesis opens a new direction for the current actuation/sensing technology in civil engineering. The materials and techniques, developed in this work, have a great potential in application of health monitoring of buildings and infrastructures.

Dong, Biqin

114

Investigation of high Curie temperature (1-x)BiSc1-yFeyO3-xPbTiO3 piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

Ceramics around the morphotropic phase boundary (MPB) in the (1-x)BiSc1-yFeyO3-xPbTiO3 solid solution were fabricated. For y =0.5, ceramics were single phase, and piezoelectric coefficients (d33) and electromechanical coupling coefficients (kp) for MPB compositions were 300 pC/N and 0.49, respectively; a level of piezoelectric activity similar to that of hard, lead zirconate titanate compositions but with TC˜60 °C higher at ˜440 °C. For ceramics with y ?0.7, dielectric measurements in combination with diffraction contrast transmission electron microscopy revealed the existence of two ferroelectric phases for most PbTiO3 contents studied. The presence of two ferroelectric phases was associated with a decrease in piezoelectric activity and although raw materials costs for y =0.7 and 0.8 with respect to y =0 were significantly lower (less Sc2O3) and TC greater (˜500 °C), d33 (˜100 pC/N) and kp (0.18) were too low to be commercially useful for actuator applications.

Sterianou, I.; Sinclair, D. C.; Reaney, I. M.; Comyn, T. P.; Bell, A. J.

2009-10-01

115

Ion Irradiation Damage in Zirconate and Titanate Ceramics for Pu Disposition  

SciTech Connect

In this paper, we discuss the effect of ion irradiation on pyrochlore-rich titanate and defect-fluorite zirconate ceramics designed for plutonium immobilisation. Samples, with Ce as an analogue for Pu, were made via oxide routes and consolidated by cold-pressing and sintering. Ion irradiation damage was carried out with 2 MeV Au2+ ions to a fluence of 5 ions nm-2 in the accelerator facilities within the Environmental Molecular Sciences Laboratory at Pacific Northwest National Laboratory. Irradiated and non-irradiated samples were examined by x-ray diffraction, scanning and transmission electron microscopy, x-ray photoelectron and infra-red spectroscopy, and spectroscopic ellipsometry. Samples underwent accelerated leach testing at pH 1.75 (nitric acid) at 90°C for 28 days. The zirconate samples were more ion-irradiation damage resistant than the titanate samples, showing little change after ion-irradiation whereas the titanate samples formed an amorphous surface layer ~ 500 nm thick. While all samples had high aqueous durability, the titanate leach rate was ~ 5 times that of the zirconate. The ion-irradiation increased the leach rate of the titanate without impurities by ~ 5 times. The difference in the leach rates between irradiated and unirradiated zirconate samples is small. However, the zirconates were less able to incorporate impurities than the titanate ceramics and required higher sintering temperatures, ~ 1500°C compared to 1350°C for the titanates.

Stewart, Martin W.; Begg, Bruce D.; Finnie, K.; Colella, Michael; Li, H.; McLeod, Terry; Smith, Katherine L.; Zhang, Zhaoming; Weber, William J.; Thevuthasan, Suntharampillai

2004-07-01

116

Study of Thermo-Electro-Mechnical Coupling in Functionally Graded Metal-Ceramic Composites  

E-print Network

to 11, the deflection was somewhat steady at 70% of the maximum value. The stress however continues to decrease with increasing layers. This is true even with an 4 increase in the voltage applied. For these studies, a Barium Titanate ceramic... piezoelectric ceramics of Perovskite polycrystalline structures such as Barium Titanate, Lead Zirconate Titanate and other ceramics of the type 3ABO (oxygen octahedral type unit cell), as shown in Fig. 1. 10 Figure 1: Perovskite structure...

Doshi, Sukanya 1988-

2012-12-10

117

Piezoelectric and Dielectric Performance of Poled Lead Zirconate Titanate Subjected to Electric Cyclic Fatigue  

SciTech Connect

Poled lead zirconate titanate (PZT) material as a single-layer plate was tested using piezodilatometer under electric cyclic loading in both unipolar and bipolar modes. Their responses were evaluated using unipolar and bipolar measurements on the same setup. Mechanical strain and charge density or polarization loops exhibited various variations when the material was cycled to more than 10^8 cycles. Important quantities including loop amplitude, hysteresis, switchable polarization, coercive field have been characterized accordingly under corresponding measurement conditions. At the same time, offset polarization and bias electric field of the material were observed to be changed and the trend was found to be related to the measurement condition also. Finally, the piezoelectric and dielectric coefficients were analyzed and their implications to the application of interest have been discussed.

Wang, Hong [ORNL; Matsunaga, Tadashi [ORNL; Lin, Hua-Tay [ORNL; Mottern, Alexander M [ORNL; Wereszczak, Andrew A [ORNL

2012-01-01

118

Piezoelectric Properties of Bismuth Layer-Structured Ferroelectric Ceramics with Sr-Bi-Ti-Ta System  

Microsoft Academic Search

Grain orientation effects of Sr-Bi-Ti-Ta system, especially Sr x Bi 4 m x Ti 3 m x Ta x O 12 ( m = 3, x = 0-2) [SBTT3( x )] ceramics which belong to a bismuth layer-structured ferroelectric (BLSF) family, are studied using the hot-forging (HF) method on their piezoelectric properties. The grain orientation (HF) effects enhance the piezoelectric

Hajime Nagata; Tadashi Takenaka

2002-01-01

119

Study on the prestressed sandwich piezoelectric ceramic ultrasonic transducer of torsional-flexural composite vibrational mode.  

PubMed

Based on the classical torsional and flexural vibrational theory of a slender rod, the prestressed sandwich torsional-flexural composite mode piezoelectric ceramic ultrasonic transducer is studied. This type of transducer consists of the slender metal rods and the longitudinally and tangentially polarized piezoelectric ceramic rings. The resonance frequency equations for the torsional and flexural vibrations in the transducers are derived. The simultaneous resonance of the torsional and flexural vibrations in the transducer is acquired by correcting the length of the metal slender rods resulting from the piezoelectric ceramic elements. The experimental results show that the measured resonance frequencies of the transducers are in good agreement with the computed ones, and the measured resonance frequencies of the torsional and the flexural vibrations in the composite transducers are also in good agreement with each other. PMID:12186032

Shuyu, Lin

2002-08-01

120

Comparison of several methods to characterise the high frequency behaviour of piezoelectric ceramics for transducer applications  

PubMed

Thickness mode resonances in commercial piezoelectric ceramics have been characterised as a function of frequency by two methods. The first is based on a fit on the electrical impedance for the fundamental and the overtones. This method has been applied to a large number of PZT ceramic samples and frequency dependence for all the parameters is investigated, in particular for the piezoelectric coefficient e33. The second is based on the measurement of the mechanical displacement at the centre of the surface of a PZT ceramic disk. With a modified KLM scheme, this displacement is modelled. The dielectric, elastic and piezoelectric parameters are extracted and compared for the fundamental and the third overtone. The results are found to be in good agreement. PMID:10829662

Tran-Huu-Hue; Levassort; Felix; Damjanovic; Wolny; Lethiecq

2000-03-01

121

Thickness effect on the dielectric, ferroelectric, and piezoelectric properties of ferroelectric lead zirconate titanate thin films  

NASA Astrophysics Data System (ADS)

Lead zirconate titanate (PbZr0.52Ti0.48O3-PZT) thin films with different thicknesses were deposited on Pt(111)/Ti/SiO2/Si substrates by a sol-gel method. Single perovskite phase with (111)-texture was obtained in the thinnest films, whereas with the increase in thickness the films changed to a highly (100)-oriented state. An increase in the mean grain size as the film thickness increased was also observed. Dielectric, ferroelectric, and piezoelectric properties were analyzed as a function of the film thickness and explained based on film orientation, grain size, domain structure, domain wall motion, and nonswitching interface layers. Both serial and parallel capacitor models were used to analyze the influence of the nonswitching interface layer in the dielectric properties and the effect of substrate clamping in the microscopic piezoelectric response as the film thickness decreased. The scanning force microscopy technique was used to study the effect of thickness on the microscopic piezoresponse. Significant differences between the macroscopic and microscopic electrical properties of the films were observed. Those differences can be assigned to changes in the nonswitching film-electrode layer and domain structure.

Pérez de la Cruz, J.; Joanni, E.; Vilarinho, P. M.; Kholkin, A. L.

2010-12-01

122

Synthesis and processing of barium titanate ceramics from alkoxide solutions and monolithic gels  

Microsoft Academic Search

We report the sol-gel processing of barium titanate (BaTiOâ) ceramics from methoxyethoxide precursors. The effects of heat treatment on phase and microstructure development for solution- and gel-derived ceramics are reported. Drying of monolithic alcogels yielded the low-temperature (T < 125 °C) crystallization of BaTiOâ. Crystallization was associated with gel syneresis. Nanocrystalline BaTiOâ gels which crystallized before the removal of solvent

Matthew H. Frey; David A. Payne

1995-01-01

123

Piezoelectric Ceramics Nonlinear Behavior. Application to Langevin Transducer  

NASA Astrophysics Data System (ADS)

Drastic behavior changes occur for power transducers using PZT type of ceramics. A better characterization under high excitations is then required for piezoelectric materials Indeed, characteristic nonlinear behaviors such as resonance frequency shift with hysteresis effect and overtones generation are observed experimentally. They result in front mass displacement saturation, drop in performances and instabilities. To interpret such features, a nonlinear approach is proposed. This resulting nonlinear model has been applied to the transducer and simulations are given. The comparison between numerical simulations and experimental results shows good agreement. Usually, observed saturation effects are interpreted as in term of viscous factor increase, our nonlinear approach gives an alternative explanation that explains also others observed phenomena. Des changements importants de comportement sont observés sur des transducteurs de puissance utilisant des céramiques de type PZT. Une meilleure caractérisation de matériaux piézoélectriques sous hauts niveaux s'avère alors nécessaire. En effet, des phénomèni caractéristiques d'un comportement non linéaire tels que le décalage de la fréquence de résonance avec hystérésis ou la génération d'harmoniques ont été observés expérimentalement. Ceci se traduit pax des effets de saturation du niveau de déplacement de la face avant, une limitation des performances du système et un fonctionnement instable. Afin d'interpréter de tels comportements, une théorie non linéaire est proposée. Ce modèle a ensuite été appliqué à notre structure de transducteur. Une comparaison entre simulations et résultats expérimentaux a permis de valider cette nouvelle approche. Les effets de saturation observés ont été jusqu'à présent toujours reliés à la variation du coefficient d'amortissement, notre étude a permis de démontrer qu'une autre explication liée aux non linéarités était possible et permettait en même temps d'expliquer d'autres phénomènes observés.

Guyomar, D.; Aurelle, N.; Eyraud, L.

1997-06-01

124

Application of gelcasting to the fabrication of piezoelectric ceramic parts  

Microsoft Academic Search

Gelcasting is a novel method for the molding of ceramic powder based on a synthesis of concepts derived from traditional ceramics and polymer chemistry. Although a wealth of literature has been published describing the application of the technology to the fabrication of structural ceramics, little has been reported about its application to the fabrication of functional ceramics. In order to

Dong Guo; Kai Cai; Longtu Li; Zhilun Gui

2003-01-01

125

Titanate ceramics for the immobilization of sodium-bearing high-level nuclear waste  

Microsoft Academic Search

The phase chemistries and microstructures of titanate-based ceramics containing simulated high-level nuclear waste with varying sodium contents were compared. Incorporation of relatively low sodium levels resulted in more complex phase assemblages. The principal hosts for sodium were hibonite and freudenbergite, and, when iron and sodium were present in combination, loveringite was also stabilized. During fabrication, oxygen potential was controlled by

WILLIAM J. BUYKX; KATE HAWKINS; DESMOND M. LEVINS; HISAYOSHI MITAMURA; ROGER St. C. SMART; GEOFFRY T. STEVENS; KENNETH G. WATSON; DAVID WEEDON; TIMOTHY J. WHITE

1988-01-01

126

High-power piezoelectric characteristics of textured bismuth layer structured ferroelectric ceramics.  

PubMed

Abstract-The high-power piezoelectric characteristics in h001i oriented ceramics of bismuth layer structured ferroelectrics (BLSF), SrBi(2)Nb(2)O(9) (SBN), (Bi,La)(4)Ti(3)O(12) (BLT), and CaBi(4)Ti(4)O(15) (CBT), were studied by a constant voltage driving method. These textured ceramics were fabricated by a templated grain growth (TGG) method, and their Lotgering factors were 95%, 97%, and 99%, respectively. The vibration velocities of the longitudinal mode (33-mode) increased proportionally to an applied electric field up to 2.5 m/s in these textured BLSF ceramics, although, the vibration velocity of the 33-mode was saturated at more than 1.0 m/s in the Pb(Mn,Nb)O(3)-PZT ceramics. The resonant frequencies were constant up to the vibration velocity of 2.5 m/s in the SBN and CBT textured ceramics; however, the resonant frequency decreased with increasing over the vibration velocity of 1.5 m/s in the BLT textured ceramics. The dissipation power density of the BLT was almost the same as that of the Pb(Mn,Nb)O(3)-PZT ceramics. However, the dissipation power densities of the SBN and CBT were lower than those of the BLT and Pb(Mn,Nb)O(3)-PZT ceramics. The textured SBN and CBT ceramics are good candidates for high-power piezoelectric applications. PMID:18276545

Ogawa, Hirozumi; Kawada, Shinichiro; Kimura, Masahiko; Shiratsuyu, Kousuke; Sakabe, Yukio

2007-12-01

127

Titan  

NASA Technical Reports Server (NTRS)

The following topics are discussed with respect to Titan: observations of the atmosphere; laboratory simulations and theoretical models of Titan's atmosphere; endpoints of atmospheric chemistry - aerosols and oceans; exobiology; and the next steps in understanding Titan.

Owen, Tobias; Gautier, Daniel; Raulin, Francois; Scattergood, Thomas

1992-01-01

128

Resonant magnetoelectric coupling in trilayers of ferromagnetic alloys and piezoelectric lead zirconate titanate: The influence of bias magnetic field  

Microsoft Academic Search

We present the first data and theory for the bias magnetic field dependence of magnetoelectric coupling in the electromechanical resonance (EMR) region for ferromagnetic-piezoelectric heterostructures. Trilayers of Permendur, a Co-Fe-V alloy, and lead zirconate titanate were studied. Measurements of the magnetoelectric (ME) voltage coefficient alphaE indicate a strong ME coupling in the low-frequency range and a giant ME effect due

G. Srinivasan; C. P. de Vreugd; V. M. Laletin; N. Paddubnaya; M. I. Bichurin; V. M. Petrov; D. A. Filippov

2005-01-01

129

Study of methods for automated crack inspection of electrically poled piezoelectric ceramics.  

SciTech Connect

The goal of this project was to identify a viable, non-destructive methodology for the detection of cracks in electrically poled piezoelectric ceramics used in neutron generator power supply units. The following methods were investigated: Impedance Spectroscopy, Scanning Acoustic Microscopy, Lock-in Thermography, Photo-acoustic Microscopy, and Scanned Vicinal Light. In addition to the exploration of these techniques for crack detection, special consideration was given to the feasibility of integrating these approaches to the Automatic Visual Inspection System (AVIS) that was developed for mapping defects such as chips, pits and voids in piezoelectric ceramic components. Scanned Vicinal Light was shown to be the most effective method of automatically detecting and quantifying cracks in ceramic components. This method is also very effective for crack detection in other translucent ceramics.

Yang, Pin; Hwang, Stephen C.; Jokiel, Bernhard, Jr.; Burns, George Robert

2004-06-01

130

Radially composite piezoelectric ceramic tubular transducer in radial vibration.  

PubMed

The radially composite piezoelectric tubular transducer is studied. It is composed of radially poled piezoelectric and a long metal tube. The electro-mechanical equivalent circuit of the radially poled piezoelectric and metal tube in radial vibration is obtained. Based on the force and velocity boundary conditions, the six-port electro-mechanical equivalent circuit for the composite tubular transducer is given and the resonance/anti-resonance frequency equations are obtained. The relationship between the resonance frequency and the dimensions is analyzed. Numerically simulated results obtained by the finite element method are compared with those from the analytical method. Composite piezoelectric tubular transducers are designed and manufactured. The resonance/anti-resonance frequencies are measured, and it is shown that the theoretical results are in good agreement with the simulated and experimental results. It is expected that radially composite piezoelectric tubular transducers can be used as high-power ultrasonic radiators in ultrasonic applications, such as ultrasonic liquid processing. PMID:22083782

Shuyu, Lin; Shuaijun, Wang

2011-11-01

131

Influence of the Niobium or Fluorine Dopant Concentration on the Properties of Mn-Doped Lead Zirconate Titanate Ceramics  

NASA Astrophysics Data System (ADS)

In this paper, we report on the effect of donor addition (Nb5+ or F-) on the electrical and piezoelectric properties and crystallographic characteristics of Mn-doped lead zirconate titanate (PZT) ceramics. Samples were prepared chemically by coprecipitation of oxalates and hydroxides. The niobium ion was incorporated in the B site whereas the fluorine ion was introduced in the anionic site. Structural analysis (XRD) and measurement of electrical properties were carried out. Electron spin resonance was used to determined the valency states of manganese in PZT ceramics. From the experimental results, the F-O substitution decreases the amount of oxygen vacancies in the Mn-doped PZT, and the valency states remain unchanged. However, a small number of oxygen vacancies may exist in PZT doped with 1 at.% manganese and 2 at.% fluorine. In the (Mn,Nb) co-doping case, the valency states vary from 4+ to 2+ and the number of oxygen vacancies is lower or even almost equal to zero. Thus the electroneutrality is achieved by lead vacancies.

Boucher, Eric; Guiffard, Benoit; Lebrun, Laurent; Guyomar, Daniel

2004-08-01

132

High-Power Piezoelectric Characteristics of Textured Bismuth Layer Structured Ferroelectric Ceramics  

Microsoft Academic Search

The high-power piezoelectric characteristics in c-axis oriented ceramics of bismuth layer structured ferroelectrics (BLSF), SrBi2Nb2O9 (SBN), Bi4Ti3O12 (BIT) and CaBi4Ti4O15 (CBT), were studied by constant voltage driving method. These textured ceramics were fabricated by templated grain growth (TGG) method, and their Lotgering factors were 95%, 97%, and 99%, respectively. The vibration velocities increased proportionally to an applied electric field up

H. Ogawa; S. Kawada; M. Kimura; K. Shiratsuyu; Y. Sakabe

2007-01-01

133

Phase transition and high dielectric constant of bulk dense nanograin barium titanate ceramics  

SciTech Connect

Barium titanate (BTO) ceramics with an average grain size of 8 nm were fabricated and studied. The temperature dependent Raman spectra revealed successive transitions from rhombohedral to orthorhombic, tetragonal, and cubic as the temperature increased from 87 to 673 K. Local piezoresponse force measurements indicated that the ceramics had switchable polarization at room temperature. Dielectric measurements showed a broad ferroelectric-to-paraelectric phase transition with a maximum permittivity of 1800 at 390 K. All these results suggest that ferroelectricity could remain in BTO ceramics with grain size as small as 8 nm in diameter.

Wang Xiaohui; Deng Xiangyun; Wen Hai; Li Longtu [State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

2006-10-16

134

Molten-Salt Synthesis of Bismuth Titanate and Fabrication of PbTiO3-based Textured Ceramics  

Microsoft Academic Search

Grain-oriented ceramics, in which the grains are aligned around a preferred crystallographic axis, are of interest for increasing the figure of merit of piezoelectric ceramics. Templated grain growth (TGG), in which a fine matrix is recrystallised upon oriented seed crystals, is one of the more successful techniques for preparing ceramics with such crystallographic texture. Seeds are usually required to exhibit

Jingyan He; T. P. Comyn; T. Skidmore; S. J. Milne; A. J. Bell

2006-01-01

135

EXAFS and XANES analysis of plutonium and cerium edges from titanate ceramics for fissile materials disposal.  

SciTech Connect

We report x-ray absorption near edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) spectra from the plutonium L{sub III} edge and XANES from the cerium L{sub II} edge in prototype titanate ceramic hosts. The titanate ceramics studied are based upon the hafnium-pyrochlore and zirconolite mineral structures and will serve as an immobilization host for surplus fissile materials, containing as much as 10 weight % fissile plutonium and 20 weight % (natural or depleted) uranium. Three ceramic formulations were studied: one employed cerium as a ''surrogate'' element, replacing both plutonium and uranium in the ceramic matrix, another formulation contained plutonium in a ''baseline'' ceramic formulation, and a third contained plutonium in a formulation representing a high-impurity plutonium stream. The cerium XANES from the surrogate ceramic clearly indicates a mixed III-IV oxidation state for the cerium. In contrast, XANES analysis of the two plutonium-bearing ceramics shows that the plutonium is present almost entirely as Pu(IV) and occupies the calcium site in the zirconolite and pyrochlore phases. The plutonium EXAFS real-space structure shows a strong second-shell peak, clearly distinct from that of PuO{sub 2}, with remarkably little difference in the plutonium crystal chemistry indicated between the baseline and high-impurity formulations.

Fortner, J. A.; Kropf, A. J.; Bakel, A. J.; Hash, M. C.; Aase, S. B.; Buck, E. C.; Chamerlain, D. B.

1999-11-16

136

Adaptive grey control for hybrid resonant driving linear piezoelectric ceramic motor  

Microsoft Academic Search

This paper presents an adaptive grey control (AGC) system for a linear piezoelectric ceramic motor (LPCM) driven by a newly designed hybrid resonant inverter. First, the motor configuration and the driving circuit of an LPCM are introduced, and its hypothetical dynamic model is described briefly. The hybrid resonant drive system has the merits of high voltage gain from a parallel

Rong-Jong Wai; Ching-Hsiang Tu

2006-01-01

137

Ferroelectric/ferroelastic behavior and piezoelectric response of lead zirconate titanate thin films under nanoindentation  

NASA Astrophysics Data System (ADS)

The electromechanical response of pure lead zirconate titanate (PZT) and Mn-doped PZT thin ferroelectric films under nanoindentation forces of up to 500 mN was investigated. The stress-induced current transients were measured as a function of the externally applied load on films of different thicknesses using a spherical WC-Co cermet indenter of 500 ?m nominal radius. It was found that the quasi-static current generated through the direct piezoelectric effect is superimposed with a contribution from irreversible domain processes during the loading/unloading cycle. The film thickness dependency of the electrical transients and an asymmetry of the current-force curves are attributed to the in-plane clamping stress in the films produced by a dissimilar substrate. Analysis of corresponding charge-force hysteresis loops revealed a significant role for the residual stress state on the polarization switching in thin films. By the application of an indentation force, a portion of Barkhausen jumps was empirically estimated to increase as a consequence of reduction of the clamping effect on domains. The Rayleigh hysteretic charge-force curves showed recovery of the charge released during the load-unload stress cycle. For the thicker 700 nm films, the total charge released during loading was fully recovered with weak hysteresis. In contrast, strong in-plane clamping stresses in the 70 nm thick films are suggested to be reponsible for incomplete recovery upon unloading. A considerable domain-wall contribution to the electromechanical response was demonstrated by an enhanced polarization state, which was shown by an increase of the effective piezoelectric coefficient deff of about 35% of its initial value for the thin films at a maximum force of 500 mN.

Koval, V.; Reece, M. J.; Bushby, A. J.

2005-04-01

138

Bending strength of piezoelectric ceramics and single crystals for multifunctional load-bearing applications.  

PubMed

The topic of multifunctional material systems using active or smart materials has recently gained attention in the research community. Multifunctional piezoelectric systems present the ability to combine multiple functions into a single active piezoelectric element, namely, combining sensing, actuation, or energy conversion ability with load-bearing capacity. Quantification of the bending strength of various piezoelectric materials is, therefore, critical in the development of load-bearing piezoelectric systems. Three-point bend tests are carried out on a variety of piezoelectric ceramics including soft monolithic piezoceramics (PZT-5A and PZT-5H), hard monolithic ceramics (PZT-4 and PZT-8), single-crystal piezoelectrics (PMN-PT and PMN-PZT), and commercially packaged composite devices (which contain active PZT-5A layers). A common 3-point bend test procedure is used throughout the experimental tests. The bending strengths of these materials are found using Euler-Bernoulli beam theory to be 44.9 MPa for PMN-PZT, 60.6 MPa for PMN-PT, 114.8 MPa for PZT- 5H, 123.2 MPa for PZT-4, 127.5 MPa for PZT-8, 140.4 MPa for PZT-5A, and 186.6 MPa for the commercial composite. The high strength of the commercial configuration is a result of the composite structure that allows for shear stresses on the surfaces of the piezoelectric layers, whereas the low strength of the single-crystal materials is due to their unique crystal structure, which allows for rapid propagation of cracks initiating at flaw sites. The experimental bending strength results reported, which are linear estimates without nonlinear ferroelastic considerations, are intended for use in the design of multifunctional piezoelectric systems in which the active device is subjected to bending loads. PMID:22711404

Anton, Steven R; Erturk, Alper; Inman, Daniel

2012-06-01

139

Intra-grain composition nonuniform barium strontium calcium titanate ceramics by sol-gel pervasion techniques  

NASA Astrophysics Data System (ADS)

The use of ferroelectric ceramics in microwave devices requires that they possess low-loss, frequency-stable and highly tunable properties. The problems of traditional barium strontium calcium titanate ceramics are higher loss and inappropriate work temperature dependence. In this work, a conventional mixed oxide route was used to prepare BaTiO3, SrTiO3 and CaTiO3 precursor powders. The BaTiO3, SrTiO3 and CaTiO3 powders were thoroughly ball mill mixed. They were then added to 5 wt% polyvinyl alcohol and pressed under a uni-axial pressure of 220 MPa into discs of 12 mm diameter. We introduced nano-grains of barium strontium titanate (BST) into the BSCT ceramic by nano-grain pervasion techniques to fabricate compositionally nonuniform BSCT ceramic samples. The nano-particles of BST are prepared with the sol-gel method. The sol-gel was subjected to ultrasonic irradiation and then vacuum methods in order to easily introduce nanoparticles into bulky BSCT. The ceramics do not show a sharp change in the dielectric constant and have a wide range of Curie temperature distribution. This is attributed to the presence of a compositionally nonuniform micro-area in the samples. Compared with uniform-composition BSCT, compositionally nonuniform BSCT has favourable dielectric properties. These results suggest that the compositionally nonuniform BSCT ceramics are promising candidates as tunable microwave elements.

Xu, Honghai; Jin, Dengren; Wu, Wenbiao; Cheng, Jinrong

2009-03-01

140

Logarithmic frequency dependence of the piezoelectric effect due to pinning of ferroelectric-ferroelastic domain walls  

Microsoft Academic Search

Pinning of the ferroelastic-ferroelectric domain walls on randomly distributed defects in ferroelectric ceramics leads to a field dependence of the piezoelectric coefficient that is analogous to the Rayleigh law for magnetic susceptibility. It is shown in this paper that the piezoelectric coefficient of a lead zirconate titanate ferroelastic-ferroelectric system depends linearly on the logarithm of the frequency of the field.

Dragan Damjanovic

1997-01-01

141

Effect of external pressure on the dielectric temperature characteristics of cerium-modified barium titanate based ceramic  

SciTech Connect

Various particle sizes of starting barium titanate were used to examine effect of external pressure on the dielectric temperature characteristics in cerium-modified barium titanate. Transmission electron microscopy and energy dispersive spectroscopy confirmed the chemically homogeneous grain structure of the dilute solid solution of cerium-modified barium titanate. Both grain size reduction and external pressure shift the {Tc} to a lower temperature while shifting the tetragonal-orthorhombic (T{sub 1}) and rhombohedral-orthorhombic (T{sub 2}) transitions to higher temperatures. In particular, the dielectric temperature characteristics of chemically homogeneous ceramic depend on the external pressure and grain size in comparison with chemically inhomogeneous ceramic.

Park, Y. [Korea Advanced Inst. of Science and Technology, Seoul (Korea, Republic of). Dept. of Advanced Materials Engineering] [Korea Advanced Inst. of Science and Technology, Seoul (Korea, Republic of). Dept. of Advanced Materials Engineering; Kim, Y. [Korea Inst. of Science and Technology, Seoul (Korea, Republic of). Dept. of Ceramics] [Korea Inst. of Science and Technology, Seoul (Korea, Republic of). Dept. of Ceramics

1996-12-01

142

Thermo-Optical Investigation of Sodium-Bismuth Titanate Single Crystal and PLZT Ceramics  

Microsoft Academic Search

Thermal lensing in relaxor type ferroelectrics as a function of temperature has been investigated by using pulse\\/probe method. Enhanced thermo-optical (TO) properties had been observed in 3d elements (Cu, Co) doped PLZT ceramics and in sodium-bismuth titanate single crystals near phase transitions (PT). Comparison of TO signals for several doped PLZT materials reveals that 0.5 wt.% Cu doping is responsible

Guntis Liberts; Girts Ivanovs; Vilnis Dimza; Edmunds Tamanis

2005-01-01

143

Electrical Properties of Ag-Doped Barium Titanate Ceramics  

Microsoft Academic Search

Temperature dependence of electrical conductivity, thermoelectric motive force and Hall effect, electron spin resonance, X-ray analyses, voltage-current characteristics and voltage dependence of capacitance of the Ag-doped BaTiO3 ceramics were studied. The semiconducting specimens were obtained by firing the ceramic in nitrogen atmosphere. Charge carriers in the specimens are electrons in view of the sign of Hall electric and thermoelectric motive

Hiroshi Ikushima; Shigeru Hayakawa

1965-01-01

144

Titan!  

Microsoft Academic Search

Cassini-Huygens achieved Saturnian orbit on July 1, 2004. The first order of business was the safe delivery of the Huygens atmospheric probe to Titan that took place on January 14, 2005. Huygens descended under parachute obtaining observations all the way down to a safe landing. It revealed Titan for the first time. Stunning are the similarities between Titan and the

Dennis L. Matson

2010-01-01

145

Temperature dependence of self-consistent full matrix material constants of lead zirconate titanate ceramics  

NASA Astrophysics Data System (ADS)

Up to date, there are no self-consistent data in the literature on the temperature dependence of full matrix material properties for piezoelectric materials because they are extremely difficult to determine. Using only one sample, we have measured the temperature dependence of full matrix constants of lead zirconate titanate (PZT-4) from room temperature to 120 °C by resonant ultrasound spectroscopy. Self-consistency is guaranteed here because all data at different temperatures come from one sample. Such temperature dependence data would make it a reality to accurately predict device performance at high temperatures using computer simulations.

Tang, Liguo; Cao, Wenwu

2015-02-01

146

Dielectric properties of barium titanate ceramics doped by B{sub 2}O{sub 3} vapor  

SciTech Connect

The effects of B{sub 2}O{sub 3} vapor doping on the dielectric properties of barium titanate ceramics were studied. After the doping, the Curie point of BaTiO{sub 3} ceramics was increased from 128 deg. C to 130 deg. C and the maximum dielectric constant was considerably increased. X-ray diffraction showed that both the grain lattice parameters and the tetragonality were increased by the boron oxide vapor doping. It was proposed that boron interstitial was introduced into the grain lattice of barium titanate ceramics by B{sub 2}O{sub 3} vapor doping and the dielectric properties were thus obviously changed.

Qi, J.Q.; Chen, W.P.; Wang Yu; Chan, H.L.W.; Li, L.T. [Department of Applied Physics and Materials Research Center, Hong Kong Polytechnic University, Hong Kong (China); Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

2004-12-01

147

Enhanced piezoelectric performance of composite sol-gel thick films evaluated using piezoresponse force microscopy  

PubMed Central

Conventional composite sol-gel method has been modified to enhance the piezoelectric performance of ceramic thick films. Lead zirconate titanate (PZT) and lead magnesium niobate–lead titanate (PMN-PT) thick films were fabricated using the modified sol-gel method for ultrasonic transducer applications. In this work, piezoresponse force microscopy was employed to evaluate the piezoelectric characteristics of PZT and PMN-PT composite sol-gel thick films. The images of the piezoelectric response and the strain-electric field hysteresis loop behavior were measured. The effective piezoelectric coefficient (d33,eff) of the films was determined from the measured loop data. It was found that the effective local piezoelectric coefficient of both PZT and PMN-PT composite films is comparable to that of their bulk ceramics. The promising results suggest that the modified composite sol-gel method is a promising way to prepare the high-quality, crack-free ceramic thick films. PMID:23798771

Liu, Yuanming; Lam, Kwok Ho; Kirk Shung, K.; Li, Jiangyu; Zhou, Qifa

2013-01-01

148

Lead Barium Potassium Sodium Niobate Ceramics for Piezoelectric Applications  

NASA Astrophysics Data System (ADS)

This paper reports a systematic study of tungsten bronze morphotropic phase boundary (MPB) system Pb2-2X-3Y/2Ba2xREyK1-xNaxNb5O15, where, x = 0.20, 0.25, 0.30, RE = Pr and Bi and y = 0.05 and their structure, microstructure, hysteresis, dielectric, piezoelectric, and Pyroelectric properties. Enhanced piezoelectric constants kp, kt, k31, d31, d33, g31, g33, S11 E as 30.8%, 47.6%, 18.9%, 57 × 10-12 C/N, 159 × 10-12 C/N, 6.89 × 10-3 mV/N, 19.23 × 10-3 mV/N, and 13.88 × 10-12 m2/N respectively are observed in the composition for which y = 0, and x = 0.30, which is above MPB. Also, a change in thickness, 0.0159 ?m has been developed for a thickness of the sample 1.2 mm, d33 = 159 × 10-12 C/N and for an applied voltage of 100 V. The same material produces a length extension, 0.0475 ?m for d31 = 57 × 10-12 C/N, l = 10 mm, t = 1.2 mm, for an applied voltage of 100 V. Thus the material may be useful for a piezoelectric transducer. Enhanced piezoelectric coefficients, d31 = 96 × 10-12 C/N and g33 = 12.95 × 10-3 mV/N are also observed in the composition for which RE = Pr and x = 0.25.

Sambasiva Rao, K.; Vallisnath, N.; Prasad, T. N. V. K. V.; Ch. Varada Rajulu, K.; Tilak, B.; Lee, Joon Hyung

149

Wafer-scale fabrication of self-actuated piezoelectric nanoelectromechanical resonators based on lead zirconate titanate (PZT)  

NASA Astrophysics Data System (ADS)

In this paper we report an unprecedented level of integration of self-actuated nanoelectromechanical system (NEMS) resonators based on a 150?nm thick lead zirconate titanate (PZT) thin film at the wafer-scale. A top-down approach combining ultraviolet (UV) lithography with other standard planar processing technologies allows us to achieve high-throughput manufacturing. Multilayer stack cantilevers with different geometries have been implemented with measured fundamental resonant frequencies in the megahertz range and Q-factor values ranging from ~130 in air up to ~900 in a vacuum at room temperature. A refined finite element model taking into account the exact configuration of the piezoelectric stack is proposed and demonstrates the importance of considering the dependence of the beam’s cross-section upon the axial coordinate. We extensively investigate both experimentally and theoretically the transduction efficiency of the implemented piezoelectric layer and report for the first time at this integration level a piezoelectric constant of {{d}31}=15 ?fm?V?1. Finally, we discuss the current limitations to achieve piezoelectric detection.

Dezest, D.; Thomas, O.; Mathieu, F.; Mazenq, L.; Soyer, C.; Costecalde, J.; Remiens, D.; Deü, J. F.; Nicu, L.

2015-03-01

150

Properties of PZT-Based Piezoelectric Ceramics Between -150 and 250 C  

NASA Technical Reports Server (NTRS)

The properties of three PZT-based piezoelectric ceramics and one PLZT electrostrictive ceramic were measured as a function of temperature. In this work, the dielectric, ferroelectric polarization versus electric field, and piezoelectric properties of PZT-4, PZT-5A, PZT-5H, and PLZT-9/65/35 were measured over a temperature range of -150 to 250 C. In addition to these measurements, the relative thermal expansion of each composition was measured from 25 to 600 C and the modulus of rupture of each material was measured at room temperature. This report describes the experimental results and compares and contrasts the properties of these materials with respect to their applicability to intelligent aerospace systems.

Hooker, Matthew W.

1998-01-01

151

High-power piezoelectric characteristics of textured bismuth layer structured ferroelectric ceramics  

Microsoft Academic Search

The high-power piezoelectric characteristics in (001) oriented ceramics of bismuth layer structured fer-roelectrics (BLSF), SrBi2Nb2O9 (SBN), (Bi,La)4Ti3O2 (BLT), and CaBi4Ti4Oi5 (CBT), were studied by a constant voltage driving method. These textured ceramics were fabricated by a templated grain growth (TGG) method, and their Lotgering factors were 95%, 97%, and 99%, respectively. The vibration velocities of the longitudinal mode (33-mode) increased

Hirozumi Ogawa; Shinichiro Kawada; Masahiko Kimura; Kousuke Shiratsuyu; Yukio Sakabe

2007-01-01

152

Flexural resonance vibrations of piezoelectric ceramic tubes in Besocke-style scanners  

NASA Astrophysics Data System (ADS)

Flexural resonance vibrations of piezoelectric ceramic tubes in Besocke-style scanners with nanometer resolution are studied by using an electro-mechanical coupling Timoshenko beam model. Meanwhile, the effects of friction, the first moment, and moment of inertia induced by mass loads are considered. The predicted resonance frequencies of the ceramic tubes are sensitive to not only the mechanical parameters of the scanners, but also the friction acting on the attached shaking ball and corresponding bending moment on the tubes. The theoretical results are in excellent agreement with the related experimental measurements. This model and corresponding results are applicable for optimizing the structures and performances of the scanners.

Zhang, Hui; Zhang, Shu-Yi; Fan, Li

2012-08-01

153

Aging-induced dielectric relaxation in barium titanate ceramics  

NASA Astrophysics Data System (ADS)

In this letter the authors report on the aging effect on the phase transitions and dielectric properties of 1mol% Mn-doped BaTiO3 ceramics. Aging the ceramics in the ferroelectric state stimulates a resistance for the orthorhombic-tetragonal and tetragonal-cubic phase transitions, which leads to stabilization of the tetragonal phase over a wider temperature range. The dielectric constant of the aged sample shows dispersion, associated with a dielectric loss relaxation peak near the 100kHz frequency region, in contrast to the unaged one. The present results are discussed in light of the existing models for ferroelectric domain stabilization.

Ahmad, Mohamad M.; Yamada, Koji; Meuffels, Paul; Waser, Rainer

2007-03-01

154

Anisotropy of piezoelectric properties in the modified PbTiO3 ceramics  

Microsoft Academic Search

This paper describes the crystal, dielectric and piezoelectric properties in the (Pb, Me) [(CO1\\/2W1\\/2), Ti]O3 system (Me=Ca, Sr, Ba). Among these materials, the Co-modified PbTi03 ceramics show a large anisotropy in the electromechanical coupling factor. The very small value o f the planar coupling factor may not be caused by the published existing mechanism such as the bulk property of

Noboru Ichinose; Youji Fuse

1990-01-01

155

Effects of static electric field on the fracture behavior of piezoelectric ceramics  

Microsoft Academic Search

The paper gives an overview on experimental observations of the failure behavior of electrically insulating and conducting\\u000a cracks in piezoelectric ceramics. The experiments include the indentation fracture test, the bending test on smooth samples,\\u000a and the fracture test on pre-notched (or pre-cracked) compact tension samples. For electrically insulating cracks, the experimental\\u000a results show a complicated fracture behavior under electrical and

Tong-Yi Zhang

2002-01-01

156

Design, fabrication, and properties of 2-2 connectivity cement/polymer based piezoelectric composites with varied piezoelectric phase distribution  

NASA Astrophysics Data System (ADS)

The laminated 2-2 connectivity cement/polymer based piezoelectric composites with varied piezoelectric phase distribution were fabricated by employing Lead Zirconium Titanate ceramic as active phase, and mixture of cement powder, epoxy resin, and hardener as matrix phase with a mass proportion of 4:4:1. The dielectric, piezoelectric, and electromechanical coupling properties of the composites were studied. The composites with large total volume fraction of piezoelectric phase have large piezoelectric strain constant and relative permittivity, and the piezoelectric and dielectric properties of the composites are independent of the dimensional variations of the piezoelectric ceramic layer. The composites with small total volume fraction of piezoelectric phase have large piezoelectric voltage constant, but also large dielectric loss. The composite with gradually increased dimension of piezoelectric ceramic layer has the smallest dielectric loss, and that with the gradually increased dimension of matrix layer has the largest piezoelectric voltage constant. The novel piezoelectric composites show potential applications in fabricating ultrasonic transducers with varied surface vibration amplitude of the transducer.

Dongyu, Xu; Xin, Cheng; Banerjee, Sourav; Shifeng, Huang

2014-12-01

157

J. Phys. III Hance 7 (1997) 1197-1208 JUNE 1997, PAGE 1197 Piezoelectric Ceramics Nonlinear Behavior.  

E-print Network

PHYSIQUE III N°6 1. Introduction Piezoelectric ceramics, used in power transducers for sonars, ultrasonic transducers using PZT type of ceram- ics. A better characterization under high excitations is then required, first we present the nonlinearities induced in power transducer. Then we propose a theoretical

Paris-Sud XI, Université de

158

Structural and electrical characteristics of dysprosium-doped barium stannate titanate ceramics  

SciTech Connect

Effects of dysprosium (Dy) amphoteric doping on the structural, dielectric and electric properties of barium stannate titanate (BTS) ceramics have been studied. X-ray diffraction analyses reveal that all Dy-doped BTS ceramics exhibit cubic perovskite structure until to 1 mol%. Dy doping at the A site shows lower solubility than that at the B site. SEM surface morphologies display that the Dy B site doping is beneficial for the compact and homogeneous grain distribution. The dielectric constant and loss tangent are reduced with increase of the doping levels. Impedance spectroscopy investigation demonstrates that all samples are insulating at room temperature. Doping alters the full resistive regions of pure BTS ceramics to Doped BTS with insulating grain boundaries and semiconducting bulk regions, but the doping contents has little effect on changing the electric structures.

Wang, Shijie; Tan, Tai Aik; Lai, Man On [Department of Mechanical Engineering, National University of Singapore, 9, Engineering Drive 1, Singapore 117576 (Singapore)] [Department of Mechanical Engineering, National University of Singapore, 9, Engineering Drive 1, Singapore 117576 (Singapore); Lu, Li, E-mail: luli@nus.edu.sg [Department of Mechanical Engineering, National University of Singapore, 9, Engineering Drive 1, Singapore 117576 (Singapore)] [Department of Mechanical Engineering, National University of Singapore, 9, Engineering Drive 1, Singapore 117576 (Singapore)

2010-03-15

159

Research on key technique of microscopy three-dimensional image reconstruction based on piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

Due to the limited depth of focus of microscope objective, a series of images taken from different sections and directions are needed to reconstruct 3D microscopy image. In this paper, we present a novel method which utilizes piezoelectric actuator, high magnification microscopy system without mirror and single CCD to observe micro-objects and reconstruct its three-dimensional image. Inverse piezoelectric effect of piezoelectric ceramics have some superior characteristics, such as high positioning resolution, high positioning accuracy, etc. And piezoelectric actuator possess the advantage of small-size, strong-power and easy- to-integrated as well. Based on these points, we designed a 360° rotation and tilt positioning platform. In this platform, Piezoelectric actuator is employed to ensure the positioning accuracy at axis-Z direction. At the same time, Motion of 360° rotation and tilt can be controlled precisely using stepping motor controlling technology. Furthermore, finite element methods (FEM) analyze software--ANSYS is used to analyze the rigidity, stress and structure optimization of the platform. This rotation and tilt mechanical positioning platform can help the single CCD to get clear, complete-view two dimensional images. This method paves the way for three-dimensional reconstruction of micro objects. Experiments demonstrate that this 360° rotation and tilt positioning stage is structure-simple and high-accurate. It can be widely used in micro-structure observing and three-dimensional image reconstruction among mechanics, materials and biology, etc.

Wang, Jianhua; Xiao, Zexin

2011-11-01

160

Dielectric and piezoelectric properties of S001ceramics  

E-print Network

TiO3 ceramics Edward M. Sabolsky,a) Susan Trolier-McKinstry, and Gary L. Messing Materials Research Institute and Department of Materials Science and Engineering, The Pennsylvania State University, University. As previously stated, the enhanced electromechanical properties for the domain engineered materials have been

Messing, Gary L.

161

Low-temperature dielectric relaxations in Y-doped strontium titanate ceramics  

NASA Astrophysics Data System (ADS)

The structural and low-frequency dielectric properties of Y-doped strontium titanate ceramics prepared by the conventional mixed oxide method are investigated. The lattice parameter is found to decrease linearly in the Sr1 ? 1.5xYxTiO3 system, confirming the incorporation of Y onto the Sr site of perovskite lattice of strontium titanate up to the solid solubility limit below x = 0.05. The real and imaginary parts of the dielectric permittivity of Sr1 ? 1.5xYxTiO3 ceramics exhibit a relaxation between 100?Hz and 1?MHz in the temperature range 10–40?K, slightly shifting to higher temperatures with increasing Y content. Such dielectric behavior, yielding real part of the dielectric permittivity up to 35?000, is attributed to the relaxation of individual dipoles formed by off-center displacement of Y3+ ions on Sr sites in a highly polarizable lattice of strontium titanate. The other dielectric relaxation observed in Sr1 ? 1.5xYxTiO3 from 125 to 300?K is attributed to the oxygen vacancy related mechanisms.

Tkach, Alexander; Vilarinho, Paula M.; Almeida, Abílio

2015-03-01

162

Titan  

NASA Astrophysics Data System (ADS)

Introduction I. C. F. Müller-Wodarg, C. A. Griffith, E. Lellouch and T. E. Cravens; Prologue 1: the genesis of Cassini-Huygens W.-H. Ip, T. Owen and D. Gautier; Prologue 2: building a space flight instrument: a P.I.'s perspective M. Tomasko; 1. The origin and evolution of Titan G. Tobie, J. I. Lunine, J. Monteux, O. Mousis and F. Nimmo; 2. Titan's surface geology O. Aharonson, A. G. Hayes, P. O. Hayne, R. M. Lopes, A. Lucas and J. T. Perron; 3. Thermal structure of Titan's troposphere and middle atmosphere F. M. Flasar, R. K. Achterberg and P. J. Schinder; 4. The general circulation of Titan's lower and middle atmosphere S. Lebonnois, F. M. Flasar, T. Tokano and C. E. Newman; 5. The composition of Titan's atmosphere B. Bézard, R. V. Yelle and C. A. Nixon; 6. Storms, clouds, and weather C. A. Griffith, S. Rafkin, P. Rannou and C. P. McKay; 7. Chemistry of Titan's atmosphere V. Vuitton, O. Dutuit, M. A. Smith and N. Balucani; 8. Titan's haze R. West, P. Lavvas, C. Anderson and H. Imanaka; 9. Titan's upper atmosphere: thermal structure, dynamics, and energetics R. V. Yelle and I. C. F. Müller-Wodarg; 10. Titan's upper atmosphere/exosphere, escape processes, and rates D. F. Strobel and J. Cui; 11. Titan's ionosphere M. Galand, A. J. Coates, T. E. Cravens and J.-E. Wahlund; 12. Titan's magnetospheric and plasma environment J.-E. Wahlund, R. Modolo, C. Bertucci and A. J. Coates.

Müller-Wodarg, Ingo; Griffith, Caitlin A.; Lellouch, Emmanuel; Cravens, Thomas E.

2014-03-01

163

Electrooptic and piezoelectric measurements in photorefractive barium titanate and strontium barium niobate  

Microsoft Academic Search

Interferometric techniques are used to measure the low-frequency electrooptic and piezoelectric coefficients in undoped BaTiO3 and Sr(x)Ba(1-x)Nb2O6 (x = 0.61) crystals. Consideration is given to the contribution of the piezoelectric effect to the Pockels measurements. For an applied ac electric field in the range of 0.1-200 V\\/cm, the electrooptic and piezoelectric effects are linear in the magnitude of the applied

Stephen Ducharme; Jack Feinberg; Ratnaker R. Neurgaonkar

1987-01-01

164

Large piezoelectric effects in charged, heterogeneous fluoropolymer electrets  

Microsoft Academic Search

.   Large piezoelectric d33 coefficients around 600 pC\\/N are found in corona-charged non-uniform electrets consisting of elastically “soft” (microporous\\u000a polytetrafluoroethylene PTFE) and “stiff” (perfluorinated cyclobutene PFCB) polymer layers. The piezoelectric activity of\\u000a the two-layer fluoropolymer stack exceeds the d33 coefficient of the ferroelectric ceramic lead zirconate titanate (PZT) by more than a factor of two and that of the ferroelectric\\u000a polymer

G. S. Neugschwandtner; R. Schwödiauer; S. Bauer-Gogonea; S. Bauer

2000-01-01

165

Wavelength translation based on photoinduced broadband absorption in Nd3+ -doped lanthanum lead zirconate titanate ceramics.  

PubMed

A correlation between a photoinduced broadband absorption (BBA) and a strong long persistent optoenergy storage (LPOES), both evident in ceramic plates of neodymium-doped lanthanum-modified lead zirconate titanate (Nd:PLZT), has been proposed and verified experimentally. As a direct evidence of the suggested correlation, a 3.0 dB gain was obtained with a preilluminated Nd:PLZT plate by simply heating up the plate to 60 degrees C. Thermal history related gain profiles taken in an Nd:PLZT plate unveiled that the intrinsically rich carrier traps in the ceramics are highly responsible for the remarkable BBA and underlying LPOES, and hence thermal to near-IR wavelength translation. PMID:19448824

Zhang, Jingwen W; Li, Kewen K; Zhao, Hua; Zou, Yingyin K; Bartolo, Baldassare Di; Chen, Xuesheng

2009-05-15

166

Lasing action and optical amplification in Nd3+ doped electrooptic lanthanum lead zirconate titanate ceramics.  

PubMed

Both single-pass gain and lasing action at 1064.4 nm were observed in ceramic gain media of neodymium doped lanthanum-modified lead zirconate titanate, which exhibits good electrooptic (EO) effect from visible through mid-wave IR band (400 nm to 5.5 µm). These works have removed roadblocks off the way leading to development of long envisioned multifunctional optical devices. The impact of the Nd3+ doping concentration on the EO effect in the Nd3+:PLZT ceramics was studied. The finding of the slowly trailing-off was satisfactorily explained with the rich vacancy-based carrier traps, which are responsible for the long persistent optoenergy storage. PMID:21369120

Zhao, Hua; Sun, Xiudong; Zhang, Jingwen W; Zou, Yingyin K; Li, Kewen K; Wang, Yanyun; Jiang, Hua; Huang, Pi-Ling; Chen, Xuesheng

2011-02-14

167

Influence of processing parameters on the structure and properties of barium strontium titanate ceramics  

SciTech Connect

Barium strontium titanate (BST) with the molar formula (Ba{sub 0.8}Sr{sub 0.2}TiO{sub 3}) has been prepared by two different processing methods: mixed-oxide (BST-MO) and reaction-sintering (BST-RS). X-ray powder diffraction study shows differences in grain size and crystal symmetry for both these ceramics. The former shows a tetragonal symmetry while the latter presents a cubic symmetry. The occurrence of polar micro-regions associated with the higher chemical non-homogeneous distribution of ion defects from the influence of the processing parameters is the main reason for the higher peak dielectric constant (K{sub m}), the higher remanent polarization (P{sub r}), the higher coercive field (E{sub c}), the higher peak current density (J{sub m}), and the lower temperature of peak dielectric constant (T{sub m}) in BST-MO ceramics.

Yun Sining [School of Material Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055 (China); Department of Materials Physics, School of Science, Xi'an Jiaotong University, Xi'an 710049 (China)], E-mail: alexsyun1974@yahoo.com.cn; Wang Xiaoli [Department of Materials Physics, School of Science, Xi'an Jiaotong University, Xi'an 710049 (China); Xu Delong [School of Material Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055 (China)

2008-08-04

168

X-ray diffraction study of crystalline barium titanate ceramics  

SciTech Connect

In this study, BaTiO{sub 3} ceramics have been prepared via solid-state reaction method. The powders were calcined for 2 hours at different temperatures ranging from 600°C to 1200°C. Using X-ray diffraction with a Rietveld analysis, the phase formation and crystal structure of the BaTiO{sub 3} powders were studied. Change in crystallite size and tetragonality as a function of calcination temperature were also discussed. It has been found that the formation of pure perovskite phase of BaTiO{sub 3} began at calcination condition of 1000 °C for 2 hours. The crystal structure of BaTiO{sub 3} formed is in the tetragonal structure. The second phases of BaCO{sub 3} and TiO{sub 2} existed with calcination temperature below 1000 °C. Purity, crystallite size and tetragonality of BaTiO{sub 3} powders were found to increase with increasing calcination temperature.

Zali, Nurazila Mat; Mahmood, Che Seman; Mohamad, Siti Mariam; Foo, Choo Thye; Murshidi, Julie Adrianny [Malaysian Nuclear Agency, Bangi, 43000 Kajang Selangor (Malaysia)

2014-02-12

169

Fabrication and modeling of bismuth titanate-PZT ceramic transducers for high temperature applications  

NASA Astrophysics Data System (ADS)

Utilization of a spray-on deposition technique of ferroelectric bismuth titanate (Bi4Ti3O12) composites has a competitive advantage to standard ultrasonic transducers. These can conform to curved surfaces, can operate at high temperature (Curie-Weiss temperature 685 °C) and are mechanically well-coupled to a substrate. However, an issue with many high temperature transducers such as bismuth titanate ceramics is that they have relatively low transduction efficiency, i.e. d33 is about 12-14 pC/F in Bi4Ti3O12 versus 650 pC/F in PZT-5H. It is a common conception that high-temperature capability comes at the cost of electro-mechanical coupling. It will be shown that the high temperature capability of bismuth-titanate-PZT composite transducers using the spray-on deposition technique previously developed, improves the electro-mechanical coupling while maintaining the high temperature performance and mechanical coupling. This material could provide advantages in harsh environments where high signal-to-noise ratios are needed.

Reinhardt, B.; Searfass, C.; Cyphers, R.; Sinding, K.; Pheil, C.; Tittmann, B.

2013-01-01

170

Transducer Performance for Leaky Wave in Layered Structure of Piezoelectric Ceramic Thin Plate and Acryl Plate  

NASA Astrophysics Data System (ADS)

A leaky wave transducer in the combination of a piezoelectric ceramic thin plate and an acryl plate is described, which functions as a transducer for underwater ultrasound. The operation performance of an interdigital transducer in the layered structure is described from the viewpoint of phase velocity, electromechanical coupling constant, mode conversion efficiency and transducer efficiency. The leaky wave transducer has multiple modes with velocity dispersion. Using the second-order anti-symmetrical mode with high transducer efficiency value, a liquid-delay line oscillation is demonstrated.

Toda, Kohji; Akutsu, Yasuhiko

1994-09-01

171

Network formalism for modeling functionally gradient piezoelectric plates and stacks and simulations of RAINBOW ceramic actuators.  

PubMed

A simple network representation is given for a stack of thin, homogeneous piezoelectric plates, executing a single thickness mode of motion. All plates may differ in thickness and material properties, including dielectric loss, ohmic conductivity, and viscous loss. Each plate is driven by a thickness-directed electric field, and all stack elements are connected electrically in series. Functionally gradient single plates and composites are readily modeled by the network, to a desired precision, using a sequence of circuit elements representing stepwise variations in material properties and layer thicknesses. Simulations of RAINBOW (Reduced And Internally Biased Oxide Wafer) ceramics are given. PMID:11370360

Ballato, J; Schwartz, R; Ballato, A

2001-03-01

172

Study of the characteristics of a piezoelectric lead zirconate titanate radiation detector using a pulsed xenon source  

SciTech Connect

The detector characteristics of piezoelectric lead zirconate titanate (PZT) were studied by directly irradiating a multilayered PZT detector with 400 MeV/n xenon ions. An extracted beam was processed with a rotating slit. Thus, passed through {approx}10{sup 3} xenon ions were available for 50 to 250 {mu}s. The effect of polarization on the output signal was discussed, and the optimal electrode configuration was determined. The output signal appeared as an isolated pulse whose amplitude was qualitatively understood by the Bethe-Bloch formula. However, the calculated and the observed values differed depending on the rotation speed of the slit. A process that can explain the differences is presented here. The output signal appearing beyond the range of 400 MeV/n xenon ion beam was discussed. The sensitivity was compared with that obtained with hypervelocity collision of dust.

Miyachi, Takashi [Research Institute of Science and Engineering, Waseda University, Tokyo 169-8555 (Japan); Planetary Exploration Research Center, Chiba Institute of Technology, Narashino, Chiba 275-0016 (Japan); Fujii, Masayuki; Hasebe, Nobuyuki; Okudaira, Osamu [Research Institute of Science and Engineering, Waseda University, Tokyo 169-8555 (Japan); Takechi, Seiji; Kurozumi, Atsuma; Morinaga, Shinya; Uno, Takefumi [Graduate School of Engineering, Osaka-City University, Osaka 558-8585 (Japan); Shibata, Hiromi [Graduate School of Engineering, Kyoto-University, Kyoto-606-8501 (Japan); Kobayashi, Masanori [Planetary Exploration Research Center, Chiba Institute of Technology, Narashino, Chiba 275-0016 (Japan); Murakami, Takeshi; Uchihori, Yukio [National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Okada, Nagaya [Honda Electronics Co. Ltd., Toyohashi, Aichi 441-3193 (Japan)

2010-05-15

173

Piezoelectric Properties of Sodium Bismuth Tantalate Na0.5Bi2.5Ta2O9 Dense Ceramics  

Microsoft Academic Search

The piezoelectric properties of sodium bismuth tantalate Na0.5Bi2.5Ta2O9 (NBTa) dense ceramics were determined using 0.1 wt% Mn-doped samples. The ferroelectric properties of the NBTa ceramics were confirmed. The remanent polarization Pr and coercive field Ec were 15.5 muC\\/cm2 and 81.5 kV\\/cm at room temperature, respectively. Optimum poling conditions (temperature Tp, time tp and electric field Ep) were investigated for piezoelectric

Mitsuhiro Matsushita; Rintaro Aoyagi; Hiroaki Takeda; Soichiro Okamura; Tadashi Shiosaki

2004-01-01

174

Influence of calcined temperature and sintered technology on the properties of NBT-KBT-BT lead-free piezoelectric ceramics  

Microsoft Academic Search

The influence of calcined temperature and sintered technology on the properties of 0.85 (Na0.5Bi0.5) TiO3–0.144(K0.5Bi0.5)TiO3–0.006BaTiO3(NBT-KBT-BT) lead-free piezoelectric ceramics was investigated by conventional solid state method, and the relationship between calcined temperature, sintered technology and properties of NBT-KBT-BT lead-free piezoelectric ceramics was obtained. The influence of calcined temperature on the material phase was investigated by X-ray diffraction(XRD), the influence of sintered

Xin-you Huang; Chun-hua Gao; Zhi-gang Chen

2011-01-01

175

Piezoelectric performances of undoped ( K , Na ) NbO3 ceramics and crystals for transducers applications  

NASA Astrophysics Data System (ADS)

The aim of this work is to take control on the grain size and densification of undoped K0.5Na0.5NbO3 (KNN), from micrometer to millimeter grain sizes. For this purpose, ceramics are prepared by spark plasma sintering (SPS) and conventional sintering. Their piezoelectric properties are comparatively studied. After full structural and microstructural characterizations, high electromechanical properties (kt = 45 %, kp = 30 %, Z = 20 MRay) for conventional sintering and (kt = 45 %, kp = 48 %, Z = 30 MRay) for SPS sintering are obtained. Otherwise, millimeter grains are produced by the floating zone method used for crystal growth, and their electromechanical properties are determined and compared to their homologous ceramics. Moreover, using the characteristics of the three materials, simulated electroacoustic responses of single-element transducers are compared. The results show that KNN is suitable for transducer applications.

Bah, Micka; Giovannelli, Fabien; Schoenstein, Frédéric; Retoux, Richard; Feuillard, Guy; Le Clézio, Emmanuel; Monot-Laffez, Isabelle

2014-11-01

176

Characterization of piezoelectric ceramics and 1-3 composites for high power transducers  

NASA Astrophysics Data System (ADS)

The high power characteristics of various piezoelectric ceramics and 1-3 composites were investigated. In contrast to "hard" Pb(Zr,Ti)O3, modified (Bi0.5Na0.5)TiO3 based ceramics were found to show a relatively linear electromechanical response under high drive conditions due to their high stability of mechanical quality factor. The effects of high drive field and duty cycle on the behavior of 1-3 composites were analyzed by varying active and passive components. Improved high power characteristics of 1-3 composites were achieved by selection of optimized composite components, with enhanced electromechanical efficiency and thermal stability under high drive conditions.

Jae Lee, Hyeong; Zhang, Shujun; Meyer, Richard J.; Sherlock, Nevin P.; Shrout, Thomas R.

2012-07-01

177

Characterization of piezoelectric ceramics and 1-3 composites for high power transducers  

PubMed Central

The high power characteristics of various piezoelectric ceramics and 1-3 composites were investigated. In contrast to “hard” Pb(Zr,Ti)O3, modified (Bi0.5Na0.5)TiO3 based ceramics were found to show a relatively linear electromechanical response under high drive conditions due to their high stability of mechanical quality factor. The effects of high drive field and duty cycle on the behavior of 1-3 composites were analyzed by varying active and passive components. Improved high power characteristics of 1-3 composites were achieved by selection of optimized composite components, with enhanced electromechanical efficiency and thermal stability under high drive conditions. PMID:22893730

Jae Lee, Hyeong; Zhang, Shujun; Meyer, Richard J.; Sherlock, Nevin P.; Shrout, Thomas R.

2012-01-01

178

A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces  

NASA Technical Reports Server (NTRS)

Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (< 10(exp 4) pC/N). For instance, more than 80% of PEHT related papers are on transverse "31" mode cantilever beam type PEHTs (CBPEHTs) having piezoelectric coefficients of about 100 pC/N. The level of harvested electrical power for CBPEHTs is on the order of microW even at resonance mode. In order to harvest more electrical energy across broader bandwidth, high effective piezoelectric coefficient structures are needed. In this study, we investigate a "33" longitudinal mode, piezoelectric PZT ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements. This study demonstrated that high effective piezoelectric coefficient structures enable PEHTs to harvest more electrical energy from mechanical vibrations or motions, suggesting an effective design for high-performance low-footprint PEHTs with potential applications in military, aerospace, and portable electronics. In addition, this study provides a route for using piezoelectric multilayer stacks for active or semi-active adaptive control to damp, harvest or transform unwanted dynamic vibrations into useful electrical energy.

Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

2011-01-01

179

Alteration of cold crucible melter titanate-based ceramics: Comparison with hot-pressed titanate-based ceramic  

SciTech Connect

Synroc ceramics were synthesized in an induction-heated cold crucible at laboratory scale (1 kg) from an oxide mixture, and at industrial prototype scale (45 kg) from Synroc previously produced by sintering under load at high temperature. After melting, both materials contained the major phases of Synroc-C. The chemical durability of both melted materials, as determined by static leaching of powder samples in initially pure water at 90 C with an SA/V ratio of 20,000 m{sup {minus}1}, was equivalent to that of conventional hot-pressed Synroc-C. Cerium, used in this investigation to simulate the presence of tri- and tetravalent actinides, was found in steady-state concentrations on the order of 1 ppb (i.e., NL(Ce) {le} 10{sup {minus}6} g{center_dot}m{sup {minus}2}). The concentration in the leachates was independent of the initial CeO{sub 2} content of the Synroc (at least up to 10 wt%); moreover, it is similar to the results obtained with hot-pressed Synroc-C specifically formulated for conditioning long-lived actinides.

Advocat, T.; Leturcq, G.; Lacombe, J.; Vernaz, E.; Bonnetier, A. [CEA Centre d`Etudes de la Vallee du Rhone, Bagnols-sur-Ceze (France). Service de Confinement des Dechets; Berger, G. [Univ. Paul Sabatier, Toulouse (France); Day, R.A.; Hart, K. [Australian Nuclear Science and Technology Organisation, Menai, New South Wales (Australia)

1997-12-31

180

Longitudinal piezoelectric characterization and domain wall contributions in lead zirconate titanate thin films  

NASA Astrophysics Data System (ADS)

A pneumatic pressure charge technique was developed for the characterization of the longitudinal piezoelectric (d33) coefficient of piezoelectric thin films using the direct piezoelectric effect. It was found that the stress rig applied both normal and in-plane stresses to the film. However, the induced charge due to the in-plane stress could be eliminated by a self-compensation mechanism. Therefore accurate d33 coefficient was measured for both bulk and thin film piezoelectrics, as was indicated by calibrations using laser interferometry and the Berlincourt method. The d33 coefficient of sol-gel derived PZT films with compositions near the morphotropic phase boundary was measured. The effect of film thickness, preferred orientation, and composition on the d33 characteristics was investigated. The influence of the mechanical boundary condition on the effective d33 coefficient of PZT films was also demonstrated. The domain wall motions and their contributions to the dielectric and piezoelectric properties of PZT films was investigated. To separate the intrinsic and the extrinsic dielectric responses, measurements at 4K were made to freeze the domain wall motions. The extrinsic contribution to the piezoelectric properties in PZT films was investigated by studying the stress and electric field dependence of the piezoelectric coefficients. In addition, though studying the influence of uniaxial stress and dc electric field on the dielectric properties, both the ferroelectric and ferroelastic activities of the non-180° domain walls in these films were evaluated. At room temperature, 180* domain wall motion was found to be present in all the films, and it increased with increasing film thickness and grain size. However, non-180° domain wall motion was significantly limited in fine grained PZT films, resulting in small extrinsic contribution to the piezoelectric properties. It was also found that the activity of the ferroelastic domain walls increased with the grain size of the film, suggesting a small degree of domain wall pinning in coarse grained films. Finally, the domain structures was studied us transmission electron microscope.

Xu, Fei

181

Preparation and characterization of Grain-Oriented Barium Titanate Ceramics Using Electrophoresis Deposition Method under A High Magnetic Field  

NASA Astrophysics Data System (ADS)

Barium titanate (BaTiO3) grain-oriented ceramics were prepared using electrophoresis deposition (EPD) method under high magnetic field of 12 T. First, BaTiO3 nanoparticles with high c/a ratio of 1.008 and size of 84 nm were prepared by two-step thermal decomposition method with barium titanyl oxalate nanoparticles. Using the BaTiO3 slurry, BaTiO3 nanoparticle accumulations were prepared by EPD method under high magnetic field. After binder burnout, the accumulations were sintered and BaTiO3 grain-oriented ceramics were prepared. Moreover, dielectric properties of their ceramics were investigated

Kita, T.; Kondo, S.; Takei, T.; Kumada, N.; Nakashima, K.; Fujii, I.; Wada, S.; Suzuki, T. S.; Uchikoshi, T.; Sakka, Y.; Miwa, Y.; Kawada, S.; Kimura, M.

2011-10-01

182

Electron Spin Resonance Investigations and Compensation Mechanism of Europium-Doped Barium Titanate Ceramics  

NASA Astrophysics Data System (ADS)

The electron spin resonance (ESR) technique was employed to investigate the point defects and evidence of Eu2+ in Eu-doped barium titanate (EBT) ceramics sintered in air according to the formula (Ba1-xEux)Ti1-x/8O3. The charge equilibrium compensation mechanism was discussed on the basis of ESR with the aid of X-ray diffraction (XRD) and differential scanning calorimetric (DSC) techniques. Eu is incorporated into Ba sites of BaTiO3 as Eu3+ up to x=0.02 and as mixed Eu2+/Eu3+ at x=0.03, which is evidenced by Eu3+-induced Ti-vacancy defects with g=2.004 and a broad Eu2+ signal with g=1.98, and a single-phase tetragonal perovskite structure can be retained. When x? 0.04, it is concluded that high density and low porosity in highly insulating and fine-grained EBT ceramics originate from the coexistence of mixed Eu2+/Eu3+; in particular, the increase in the proportion of Eu2+ in the perovskite phase increases ceramic density, but is accompanied by emergence of the Eu2Ti2O7 phase.

Lu, Da-Yong; Sun, Xiu-Yun; Toda, Masayuki

2006-11-01

183

Electric properties of Holmium substituted SrBi4Ti4O15ceramic for High Temperature Piezoelectric Applications  

Microsoft Academic Search

Piezoelectric ceramics have been widely used for several applications, such as those in filters for mobile communications; resonators for microprocessors, actuators for inject printers and sensors for detecting shock and hard disc drives (HDDs). Recently the family Aurivillius Bismuth Layer-Structure Ferroelectrics (BLSFs) has received attention for their use in the nonvolatile Ferroelectric Random Access Memory (FeRAM). In addition BLSFs have

P. Sarah

2011-01-01

184

Antiplane mechanical and inplane electric time-dependent load applied to two coplanar cracks in piezoelectric ceramic material  

Microsoft Academic Search

This work is concerned with the dynamic response of two coplanar cracks in a piezoelectric ceramic under antiplane mechanical and inplane electric time-dependent load. The cracks are assumed to act either as an insulator or as a conductor. Laplace and Fourier transforms are used to reduce the mixed boundary value problems to Cauchy-type singular integral equations in Laplace transform domain.

Z. T. Chen; M. J. Worswick

2000-01-01

185

Ferroelectric and piezoelectric properties of vanadium-doped CaBi 4Ti 4O 15 ceramics  

Microsoft Academic Search

Vanadium-doped CaBi4Ti4O15 (CBTVx, x=0?0.2) bismuth layered structure ferroelectric (BLSF) ceramics were prepared by the solid-state reaction method. X-ray diffraction pattern showed that single phase of BLSF with m=4 formed when x?0.1. The sintering temperature of the CaBi4Ti4O15 ceramics was lowered by doping of vanadium. The effects of vanadium doping on the dielectric, ferroelectric and piezoelectric properties of CaBi4Ti4?xVx ceramics were

Jiangtao Zeng; Yongxiang Li; Qunbao Yang; Qingrui Yin

2005-01-01

186

Domain wall motion and its contribution to the dielectric and piezoelectric properties of lead zirconate titanate films  

NASA Astrophysics Data System (ADS)

In this article, domain wall motion and the extrinsic contributions to the dielectric and piezoelectric responses in sol-gel derived lead zirconate titanate (PZT) films with compositions near the morphotropic phase boundary were investigated. It was found that although the films had different thicknesses, grain sizes, and preferred orientations, similar intrinsic dielectric constants were obtained for all films between 0.5 and 3.4 ?m thick. It was estimated that about 25%-50% of the dielectric response at room temperature was from extrinsic sources. The extrinsic contribution to the dielectric constant of PZT films was mainly attributed to 180° domain wall motion, which increased with both film thickness and grain size. In studies on the direct and converse longitudinal piezoelectric coefficients of PZT films as a function of either stress or electric driving field, it was found that the ferroelastic non-180° domain wall motion was limited. Thus extrinsic contributions to the piezoelectric response were small in fine grain PZT films (especially those under 1.5 ?m in thickness). However, as the films became thicker (>5?m), nonlinear behavior between the converse piezoelectric coefficient and the electric driving field was observed. This indicated that there was significant ferroelectric non-180° domain wall motion under high external excitation in thicker films. The activity of the non-180° domain walls was studied through non-180° domain switching. For fine grain films with film thicknesses less than 2 ?m, non-180° switching was negligible. Transmission electron microscopy plan-view micrographs evidenced non-180° domain fringes in these films, where the vast majority of grains were 50-100 nm in diameter and showed a single set of domain fringes. Taken together, these measurements suggest that the pinning of non-180° domain walls is very strong in films with thickness less than 2 ?m. In thicker films, non-180° domain switching was evidenced when the poling field exceeded a threshold field. The threshold field decreased with an increase in film thickness, suggesting more non-180° domain wall mobility in thicker films. Non-180° domain switching in large grained PZT films was found to be much easier and more significant than in the fine grained PZT films.

Xu, F.; Trolier-McKinstry, S.; Ren, W.; Xu, Baomin; Xie, Z.-L.; Hemker, K. J.

2001-01-01

187

High temperature dielectric relaxation anomaly of Y3+ and Mn2+ doped barium strontium titanate ceramics  

NASA Astrophysics Data System (ADS)

Relaxation like dielectric anomaly is observed in Y3+ and Mn2+ doped barium strontium titanate ceramics when the temperature is over 450 K. Apart from the conventional dielectric relaxation analysis method with Debye or modified Debye equations, which is hard to give exact temperature dependence of the relaxation process, dielectric response in the form of complex impedance, assisted with Cole-Cole impedance model corrected equivalent circuits, is adopted to solve this problem and chase the polarization mechanism in this paper. Through this method, an excellent description to temperature dependence of the dielectric relaxation anomaly and its dominated factors are achieved. Further analysis reveals that the exponential decay of the Cole distribution parameter n with temperature is confirmed to be induced by the microscopic lattice distortion due to ions doping and the interaction between the defects. At last, a clear sight to polarization mechanism containing both the intrinsic dipolar polarization and extrinsic distributed oxygen vacancies hopping response under different temperature is obtained.

Yan, Shiguang; Mao, Chaoliang; Wang, Genshui; Yao, Chunhua; Cao, Fei; Dong, Xianlin

2014-10-01

188

The field induced e31,f piezoelectric and Rayleigh response in barium strontium titanate thin films  

NASA Astrophysics Data System (ADS)

The electric field induced e31,f piezoelectric response and tunability of Ba0.7Sr0.3TiO3 (70:30) and Ba0.6Sr0.4TiO3 (60:40) thin films on MgO and silicon was measured. The relative dielectric tunabilities for the 70:30 and 60:40 compositions on MgO were 83% and 70%, respectively, with a dielectric loss of less than 0.011 and 0.004 at 100 kHz. A linear increase in induced piezoelectricity to -3.0 C/m2 and -1.5 C/m2 at 110 kV/cm was observed in Ba0.6Sr0.4TiO3 on MgO and Ba0.7Sr0.3TiO3 on Si. Hysteresis in the piezoelectric and dielectric response of the 70:30 composition films was consistent with the positive irreversible dielectric Rayleigh coefficient. Both indicate a ferroelectric contribution to the piezoelectric and dielectric response over 40-80 °C above the global paraelectric transition temperature.

Garten, L. M.; Trolier-McKinstry, S.

2014-09-01

189

Blocking effect of crystal–glass interface in lanthanum doped barium strontium titanate glass–ceramics  

SciTech Connect

Graphical abstract: The blocking effect of the crystal–glass interface on the carrier transport behavior in the lanthanum doped barium strontium titanate glass–ceramics: preparation and characterization. - Highlights: • La{sub 2}O{sub 3} addition promotes the crystallization of the major crystalline phase. • The Z? and M? peaks exist a significant mismatch for 0.5 mol% La{sub 2}O{sub 3} addition. • The Z? and M? peaks separate obviously for 1.0 mol% La{sub 2}O{sub 3} addition. • Crystallite impedance decreases while crystal–glass interface impedance increases. • La{sub 2}O{sub 3} addition increases blocking factor of the crystal–glass interface. - Abstract: The microstructures and dielectric properties in La{sub 2}O{sub 3}-doped barium strontium titanate glass–ceramics have been investigated by scanning electron microscopy (SEM) and impedance spectroscopy. SEM analysis indicated that La{sub 2}O{sub 3} additive decreases the average crystallite size. Impedance spectroscopy revealed that the positions of Z? and M? peaks are close for undoped samples. When La{sub 2}O{sub 3} concentration is 0.5 mol%, the Z? and M? peaks show a significant mismatch. Furthermore, these peaks separate obviously for 1.0 mol% La{sub 2}O{sub 3} addition. With increasing La{sub 2}O{sub 3} concentration, the contribution of the crystallite impedance becomes smaller, while the contribution of the crystal–glass interface impedance becomes larger. More interestingly, it was found that La{sub 2}O{sub 3} additive increases blocking factor of the crystal–glass interface in the temperature range of 250–450 °C. This may be attributed to a decrease of activation energy of the crystallite and an increase of the crystal–glass interface area.

Wang, Xiangrong [Beijing Fine Ceramics Laboratory, State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Zhang, Yong, E-mail: yzhang@tsinghua.edu.cn [Beijing Fine Ceramics Laboratory, State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Baturin, Ivan [Ferroelectric Laboratory, Institute of Natural Science, Ural Federal University, Ekaterinburg 620000 (Russian Federation); Liang, Tongxiang [Beijing Fine Ceramics Laboratory, State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)

2013-10-15

190

The Dielectric and Electric Characteristics of Piezoelectric Ceramics for Ultrasonic Oscillator Application  

NASA Astrophysics Data System (ADS)

The application of the ultrasonic nozzle has been extended because it can atomize liquid material. In this study, the characteristics of the ultrasonic nozzle and ceramic oscillator were investigated. The oscillator for the ultrasonic nozzle is made of piezoelectric ceramic of Pb[(Sb1/2Nb1/2)0.035, (Mn1/3Nb2/3)0.065, (ZrxTi1-x)0.90O3 The electromechanical coupling factor (kp) and mechanical quality factor (Qm) were 0.555 and 1,214, respectively, when the Zr/Ti ratio was 49/51. Moreover, this oscillator will have temperature stability because its curie temperature is 322. The driving current of the ultrasonic nozzle was 80 mA, when the driving time was 10 min. Also, the surface temperature of the ceramic oscillator was 80 at a driving time of 10 min. We discovered that the ultrasonic nozzle will be subjected to stable driving after 10 min.

Lee, Su-Ho; Yoo, Ju-Hyun; Yoon, Kwang-Hee; Sug, Joung-Young; Rue, Gi-Hong; Sin, Kwang-Ho; Kim, Jin-Gyu; Hong, Jae-Il

2002-11-01

191

Dust detector using piezoelectric lead zirconate titanate with current-to-voltage converting amplifier for functional advancement  

NASA Astrophysics Data System (ADS)

This paper describes the concept of a dust monitor using lead zirconate titanate (PZT) ceramics with a large detection area. Its potential as a dust detector is experimentally demonstrated. The dust monitor has a small volume compared to an impact ionization detector with the same detection area, due to the PZT sensor. The PZT sensor, as a traditional device for the in-situ observation of hypervelocity dust particles, has been used for momentum measurement. The hypervelocity impact signals of PZT sensors are typically read by charge-sensitive amplifiers. Instead, we suggest a new method that a current-to-voltage converting amplifier is useful for interpreting the impact signal of a PZT sensor arising from dust particles down to 0.5 ?m in radius. We propose that datasets of dust impacts can be obtained with a higher statistical accuracy, if the new method is applied to instruments on forthcoming interplanetary-space-cruising spacecrafts.

Kobayashi, Masanori; Miyachi, Takashi; Hattori, Maki; Sugita, Seiji; Takechi, Seiji; Okada, Nagaya

2013-03-01

192

Depolarization field effect on dielectric and piezoelectric properties of particulate ferroelectric ceramic-polymer composites  

NASA Astrophysics Data System (ADS)

The effects of depolarization field on the dielectric and piezoelectric properties of ferroelectric ceramic particle-filled polymer-matrix composites are investigated at the underlying domain level. Phase field modeling and simulation reveals that the macroscopic properties of the composites are dominated by depolarization field effect, which depends on the arrangement and alignment rather than the size or internal grain structure of the ferroelectric particulates. It is found that 0-3 particulate composites with random dispersion of ferroelectric particles behave essentially like linear dielectric rather than ferroelectric materials, and domain-level analysis reveals the physical mechanism for lack of domain switching or hysteresis as attributed to strong depolarization effect. Thus, without effective reduction or elimination of the depolarization field, the composites cannot benefit from the functional fillers regardless of their superior properties. In order to exhibit the desired ferroelectric behaviors, it necessitates continuous ferroelectric phase connectivity in the composites.

Ma, Fengde D.; Wang, Yu U.

2015-03-01

193

Robust solder joint attachment of coaxial cable leads to piezoelectric ceramic electrodes  

SciTech Connect

A technique was developed for the solder attachment of coaxial cable leads to the silver-bearing thick film electrodes on piezoelectric ceramics. Soldering the cable leads directly to the thick film caused bonds with low mechanical strength due to poor solder joint geometry. A barrier coating of 1.5 {mu}m Cu/1.5 {mu}m Ni/1.0{mu}m Sn deposited on the thick film layer improved the strength of the solder joints by eliminating the absorption of Ag from the thick film which was responsible for the improper solder joint geometry. The procedure does not require special preparation of the electrode surface and is cost effective due to the use of non-precious metal films and the batch processing capabilities of the electron beam deposition technique.

Vianco, P.T.

1992-01-01

194

Robust solder joint attachment of coaxial cable leads to piezoelectric ceramic electrodes  

SciTech Connect

A technique was developed for the solder attachment of coaxial cable leads to the silver-bearing thick film electrodes on piezoelectric ceramics. Soldering the cable leads directly to the thick film caused bonds with low mechanical strength due to poor solder joint geometry. A barrier coating of 1.5 {mu}m Cu/1.5 {mu}m Ni/1.0{mu}m Sn deposited on the thick film layer improved the strength of the solder joints by eliminating the absorption of Ag from the thick film which was responsible for the improper solder joint geometry. The procedure does not require special preparation of the electrode surface and is cost effective due to the use of non-precious metal films and the batch processing capabilities of the electron beam deposition technique.

Vianco, P.T.

1992-08-01

195

The extrinsic nature of nonlinear behavior observed in lead zirconate titanate ferroelectric ceramic  

E-print Network

. Studies on barium~ titanate, BaTi03, and lead zir- conate titanate (PZT), Pb(Zr,Tit --x)O3,8 showThe extrinsic nature of nonlinear behavior observed in lead zirconate titanate ferroelectric February 1991) The nonlinear electric and electromechanical responses of lead zirconate titanate Pb

Cao, Wenwu

196

Ferroelectric relaxor behaviour and impedance spectroscopy of Bi2O3-doped barium zirconium titanate ceramics  

NASA Astrophysics Data System (ADS)

Bi2O3-doped barium zirconate titanate ceramics, Ba1-xBix(Zr0.05Ti0.95)O3, have been prepared by the conventional solid-state reaction method. The ferroelectric relaxor behaviour and dielectric properties have been investigated in detail. By XRD analysis, it is suggested that up to x = 0.04, Bi3+ substitutes A-site ion, and thereafter with higher Bi3+ content, it enters the B-site sub lattice. Substitution of Bi3+ ions induces ferroelectric relaxor behaviour and the degree of relaxation behaviour increases with bismuth concentration. The remanent polarization and strain behaviour show a slight increase with the substitution level. The degree of hysteresis (strain versus electric field) also reduces from 21.4% to 4.6% with bismuth substitution. Impedance measurements were made on the prepared sample over a wide range of temperatures (300-723 K) and frequencies (40 Hz-1 MHz), which show the presence of both bulk and grain boundary effects in the material. The bulk and grain boundary conductivities determined from impedance study indicate the Arrhenius-type thermally activated process. Impedance spectroscopy is shown to be an efficient method capable of detecting the contributions of the resistances of grains and grain boundaries to the complex impedance of a ceramic system, accurately estimating its electrical conductivity as well as its corresponding activation energies and drawing conclusions on its structural properties.

Mahajan, Sandeep; Thakur, O P; Bhattacharya, D K; Sreenivas, K

2009-03-01

197

New KNN-based lead-free piezoelectric ceramic for high-frequency ultrasound transducer applications  

NASA Astrophysics Data System (ADS)

Based on new KNN-based piezoelectric material 0.96(K0.48Na0.52)(Nb0.95Sb0.05)O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3 with a giant d33 of 490, a 37-MHz high-frequency ultrasound needle transducer with the aperture size of 1 mm was successfully fabricated. The obtained transducer had a high electromechanical coupling factor k t of 0.55, a good bandwidth of 56.8 % at -6 dB, and a low insertion loss of -16 dB at the central frequency. Its excellent performance is comparable to lead-containing transducer and is superior to that of any other lead-free transducer. This promising result demonstrates that this new KNN-based lead-free piezoelectric ceramic is a good candidate to replace lead-based materials for high-frequency ultrasound imaging.

Ou-Yang, Jun; Zhu, Benpeng; Zhang, Yue; Chen, Shi; Yang, Xiaofei; Wei, Wei

2015-03-01

198

Impact of critical point on piezoelectric and electrocaloric response in barium titanate  

NASA Astrophysics Data System (ADS)

The prediction that the piezoelectric tensor is diverging at the critical point is verified for BaTiO3 (BTO), which is the oldest perovskite structured ferroelectric material with an extremely long and eventful research history. Here we investigate experimentally by dielectric and calorimetric measurements the existence and the position of the critical point in the electric-field-temperature (E-T) phase diagram of BTO in the vicinity of the paraelectric to ferroelectric phase transition. Measurements of the piezoelectric coefficient d31 as a function of the temperature and the electric field applied along the [001] direction show a critical enhancement of the piezoelectric response in the vicinity of the critical point, in agreement with recent calculations by Porta [J. Phys.: Condens. MatterJCOMEL0953-898410.1088/0953-8984/22/34/345902 22, 345902 (2010)]. The electrocaloric responsivity is found to be enhanced due to the latent heat on the paraelectric to ferroelectric transition locus below the critical point.

Novak, Nikola; Pirc, Raša; Kutnjak, Zdravko

2013-03-01

199

Piezoelectric paper fabricated via nanostructured barium titanate functionalization of wood cellulose fibers.  

PubMed

We have successfully developed hybrid piezoelectric paper through fiber functionalization that involves anchoring nanostructured BaTiO3 into a stable matrix with wood cellulose fibers prior to the process of making paper sheets. This is realized by alternating immersion of wood fibers in a solution of poly(diallyldimethylammonium chloride) PDDA (+), followed by poly(sodium 4-styrenesulfonate) PSS (-), and once again in PDDA (+), resulting in the creation of a positively charged surface on the wood fibers. The treated wood fibers are then immersed in a BaTiO3 suspension, resulting in the attachment of BaTiO3 nanoparticles to the wood fibers due to a strong electrostatic interaction. Zeta potential measurements, X-ray diffraction, and microscopic and spectroscopic analysis imply successful functionalization of wood fibers with BaTiO3 nanoparticles without altering the hydrogen bonding and crystal structure of the wood fibers. The paper has the largest piezoelectric coefficient, d33 = 4.8 ± 0.4 pC N(-1), at the highest nanoparticle loading of 48 wt % BaTiO3. This newly developed piezoelectric hybrid paper is promising as a low-cost substrate to build sensing devices. PMID:24766163

Mahadeva, Suresha K; Walus, Konrad; Stoeber, Boris

2014-05-28

200

Study of influence of fuel on dielectric and ferroelectric properties of bismuth titanate ceramics synthesized using solution based combustion technique  

NASA Astrophysics Data System (ADS)

The effect of fuel characteristics on the processing and properties of bismuth titanate (BIT) ceramics obtained by solution combustion route using different fuels are reported in this paper. Dextrose, urea and glycine were used as fuel in this study. The obtained bismuth titanate ceramics were characterized by using XRD, SEM at different stages of sample preparation. It was observed that BIT obtained by using dextrose as fuel shows higher dielectric constant and higher remnant polarization due to smaller grain size and lesser c-axis growth as compared to the samples with urea and glycine as fuel. The electrical behavior of the samples with respect to temperature and frequency was also investigated to understand relaxation phenomenon.

Subohi, Oroosa; Kumar, G. S.; Malik, M. M.; Kurchania, Rajnish

2015-03-01

201

The role of interfaces on an apparent grain size effect on the dielectric properties for ferroelectric barium titanate ceramics  

Microsoft Academic Search

We report the effect of interfaces (and thus internal surface area effects) on the value of dielectric constant (K?) calculated from capacitance and geometry data for sub-micron barium titanate (BaTiO3) ceramics prepared with decreasing grain size (and grain volumes). A series model is proposed to explain the decreasing values of apparent K? obtained for grain sizes below 0.5 ?m. A

M. H. Frey; Z. Xu; P. Han; D. A. Payne

1998-01-01

202

Label Free Detection of White Spot Syndrome Virus Using Lead Magnesium Niobate-Lead Titanate Piezoelectric Microcantilever Sensors  

PubMed Central

We have investigated rapid, label free detection of white spot syndrome virus (WSSV) using the first longitudinal extension resonance peak of five lead-magnesium niobate-lead titanate (PMN-PT) piezoelectric microcantilever sensors (PEMS) 1050-700 ?m long and 850-485 ?m wide constructed from 8 ?m thick PMN-PT freestanding films. The PMN-PT PEMS were encapsulated with a 3-mercaptopropltrimethoxysilane (MPS) insulation layer and further coated with anti-VP28 and anti-VP664 antibodies to target the WSSV virions and nucleocapsids, respectively. By inserting the antibody-coated PEMS in a flowing virion or nucleocapsid suspension, label-free detection of the virions and nucleocapsids were respectively achieved by monitoring the PEMS resonance frequency shift. We showed that positive label-free detection of both the virion and the nucleocapsid could be achieved at a concentration of 100 virions (nucleocapsids)/ml or 10 virions (nucleocapsids)/100?l, comparable to the detection sensitivity of polymerase chain reaction (PCR). However, in contrast to PCR, PEMS detection was label-free, in-situ and rapid (less than 30 min), potentially requiring minimal or no sample preparation. PMID:20863681

Capobianco, Joseph; Shih, Wei-Heng; Leu, Jiann-Horng; Lo, Grace Chu-Fang; Shih, Wan Y.

2011-01-01

203

Prototyping of radially oriented piezoelectric ceramic-polymer tube composites using fused deposition and lost mold processing techniques  

NASA Astrophysics Data System (ADS)

Piezoelectric tube composite hydrophones of 3-1, 3-2, and 2-2 connectivity were developed using Fused Deposition (FD) and lost mold processing (LMP). In this work, a new series of thermoplastic binder formulations, named the ECG series, were developed for the FD process. The ECG-9 formulation exhibits mechanical, thermal, and rheological properties suitable for the Fused Deposition of functional lead zirconate titanate ceramic devices. This binder consists of 100 parts (by weight) Vestoplast 408, 20 parts Escorez 2520, 15 parts Vestowax A-227, and 5 parts Indopol H-1500. Oleic acid, oleyl alcohol, stearic acid, and stearyl alcohol (in toluene) were tested for use as a dispersant in the PZT/ECG-9 system. It was found that stearic acid adsorbs the most onto PZT powder, adsorbing 8.1 mg/m2. Using stearic acid, solutions of increasing concentration (5.0--50.0 g/l) were measured for adsorption. It was found that 30.0 g/l is the minimum concentration necessary for optimum surface coverage. The surfactant-coated powder was compounded with ECG-9 binder to create a 54 vol.% mix. The mix was extruded using a single screw extrusion apparatus into continuous lengths (>30 m) of 1.78 mm diameter filament. Fused Deposition was used to create composite designs of 3-1, 3-2, and 2-2 connectivity. After sintering, samples exhibit a sintered density greater than 97%. Sanders Prototyping (SPI) was used to manufacture molds for use with LMP techniques. Molds of 3-1, 3-2, and 2-2 connectivity were developed. The molds were infiltrated with a 55 vol.% aqueous based PZT slurry. The parts were subjected to a binder decomposition cycle, followed by sintering. Resultant samples were highly variable due to random macro-pores present in the samples after sintering. The resultant preforms were embedded in epoxy, and polished to dimensions of 8.0 mm inside diameter (ID), 14.0 mm outside diameter (OD), and 10.0 mm length (l) the OD and l dimensions are accurate to +/--2%, while the ID is accurate to +/--5%. Samples were corona poled, and the electromechanical properties were evaluated. Dielectric constant (K), hydrostatic charge coefficients (dh), and radial displacements (ur) were measured. Of the seven composite types studied, the FD-based composites with 3-2 connectivity exhibited the highest average dh of 42.4 pCN. The same 3-2 composites exhibited the highest dhgh (FOM) of 140 fm2/N.

McNulty, Thomas Francis

204

Enhanced piezoelectric and pyroelectric effects in single-phase multiferroic Bi1-xNdxFeO3 (x=0-0.15) ceramics  

NASA Astrophysics Data System (ADS)

Single-phase multiferroic Bi1-xNdxFeO3 (x=0-0.15) ceramics are polarized and their piezoelectric and pyroelectric effects are reported. The success in polarizing the ceramics originates from low electrical conductivities controlled predominantly by the Poole-Frenkel conduction mechanism. Limited internal traps due to reduced oxygen vacancies in the ceramics result in sufficiently low leakage current densities of <30mA/m2 even at a high electric field of 145kV/cm. The piezoelectric d33 coefficients of the ceramics before and after annealing at 550°C for 4h are measured to be ˜28 and ˜24pC/N, respectively. These values are higher than those of most major lead-free high-temperature piezoelectric ceramics.

Yuan, G. L.; Or, Siu Wing

2006-02-01

205

Theoretical and experimental investigation of traveling wave propagation on a several- millimeter-long cylindrical pipe driven by piezoelectric ceramic tubes.  

PubMed

A novel method is presented for investigation of the traveling wave propagation generated on a thin film pipe with a short length of several millimeters. As a bridge to connect two piezoelectric ceramic (lead zirconate titanate, PZT) tubes, a thin-film metallic glass (TFMG) pipe is fabricated by a new technique of rotating magnetron sputtering. The vibrator combines the vibration of the axial mode of the PZT tube and the radial mode of the TFMG pipe. Theoretical analyses of the TFMG pipe and PZT tube, with a comparison of the finite element modeling, clarify the vibration characteristics so that the proper geometrical sizes, suitable boundary conditions, and driving voltage signals are designed. In the experiment, the designed vibrator was fabricated and the vibration characteristics were measured by a laser Doppler vibrometer system. The pure traveling wave propagation obtained theoretically and experimentally demonstrates the validity of this work. This study shows a new way to achieve a pure traveling wave on a short cylindrical pipe driven by PZT tubes. PMID:20639154

Sun, Dongming; Wang, Sheng; Hata, Seiichi; Sakurai, Junpei; Shimokohbe, Akira

2010-07-01

206

Phenomenologically derived electric field-temperature phase diagrams and piezoelectric coefficients for single crystal barium titanate under fields along different axes  

NASA Astrophysics Data System (ADS)

The possible domain states of perovskite ferroelectrics under applied fields are reviewed and, as an illustration, a phenomenological study of barium titanate is carried out. Electric field-temperature phase diagrams, the polarization, and the lattice strain of barium titanate single crystals are calculated from the Landau-Ginzburg-Devonshire theory of ferroelectrics for applied fields up to 20 MV m-1 and for temperatures from 1 to 450 K. The calculations are carried out for fields applied along the pseudocubic [001], [101], and [111] axes, revealing the temperature and field dependence of all the ferroelectric phase transitions. Large piezoelectric coefficients can be identified close to field-induced transitions. Good agreement is seen with experimental data for the piezoelectric coefficient parallel to [001] over a wide range of temperature. The series of transitions predicted for increasing field parallel to [111] at room temperature is qualitatively similar to that observed experimentally but with somewhat larger critical fields and lower piezoelectric coefficients. Similarities are noted between the phase diagrams for fields along [001] and [111] and those describing PbBa2+ and ZrTi4+ substitutions.

Bell, A. J.

2001-04-01

207

Piezoelectric and Mechanical Properties of BaBi4Ti4O15\\/Ba4Ti13O30 Ceramics  

Microsoft Academic Search

This article presents the piezoelectric and mechanical properties of bismuth layer-structured ferroelectrics (BLSF)-based BaBi4Ti4O15 ceramics incorporating Ba4Ti13O30. The ceramic compositions, (1-x)BaBi4Ti4O15 xBa4Ti13O30 with x=0 100 vol%, are obtained through solid-state reaction processes. The dielectric constant, ?33T\\/?0, decreases exponentially from 220 to 97 with increasing x from 0 to 66 vol%. The electromechanical coupling factor, k33, decreases from 15 to 7%

Yasuhiro Nakai; Shuichi Fukuoka

1999-01-01

208

Morphotropic phase boundary and electric properties in (1-x)Bi0.5Na0.5TiO3-xBiCoO3 lead-free piezoelectric ceramics  

E-print Network

-free piezoelectric ceramics Fei-Fei Guo, Bin Yang, Shan-Tao Zhang, Xiao Liu, Li-Mei Zheng et al. Citation: J. Appl ceramics Appl. Phys. Lett. 101, 252905 (2012) Enhanced piezoelectric performance from carbon fluoropolymer phase boundary and electric properties in (12x)Bi0.5Na0.5TiO3-xBiCoO3 lead-free piezoelectric ceramics

Cao, Wenwu

209

Miniature cryogenic valves for a Titan Lake sampling system  

NASA Astrophysics Data System (ADS)

The Cassini mission has revealed Titan to be one of the most Earthlike worlds in the Solar System complete with many of the same surface features including lakes, river channels, basins, and dunes. But unlike Earth, the materials and fluids on Titan are composed of cryogenic organic compounds with lakes of liquid methane and ethane. One of the potential mission concepts to explore Titan is to land a floating platform on one of the Titan Lakes and determine the local lake chemistry. In order to accomplish this within the expected mass volume and power budgets there is a need to pursue the development for a low power lightweight cryogenic valves which can be used along with vacuum lines to sample lake liquid and to distribute to various instruments aboard the Lander. To meet this need we have initiated the development of low power cryogenic valves and actuators based on a single crystal piezoelectric flextensional stacks produced by TRS ceramics Inc. Since the origin of such high electromechanical properties of Relaxor-PT single crystals is due to the polarization rotation effect, (i.e., intrinsic contributions), the strain per volt decrease at cryogenic temperatures is much lower than in standard Lead Zirconate Titanate (PZT) ceramics. This makes them promising candidates for cryogenic actuators with regards to the stroke for a given voltage. This paper will present our Titan Lake Sampling and Sample Handling system design and the development of small cryogenic piezoelectric valves developed to meet the system specifications.

Sherrit, Stewart; Zimmerman, Wayne; Takano, Nobuyuki; Avellar, Louisa

2014-04-01

210

Characterization of Lead-Free B{sub 2}O{sub 3} Doped Barium Stannate Titanate Ceramics  

SciTech Connect

Lead-free barium stannate titanate ceramics doped with 2 wt% of B{sub 2}O{sub 3} were prepared via a solid state sintering. The optimum condition for the preparation was carried out. Properties of the lead free material were characterized by various methods. The high dielectric constant >14000 with low tan delta 0.040 was observed at 34 deg. C for the samples prepared at the optimum condition. Plots of dielectric permittivity as a function of temperature showed that the ceramics exhibit a diffuse ferroelectric-paraelectric phase transition. The dielectric constant was also measured as a function of electric field. The dielectric-electric field measurement indicated that this material exhibits a high tunability. In addition, mechanical property such as hardness was investigated. Relation between grain size and hardness of the ceramics was found to obey the Hall-Petch equation: H{sub v} = 0.07+12.9G{sup -(1/2)}.

Tawichai, N.; Pengpat, K.; Rujijanagul, G. [Department of Physics, Faculty of Science, Chiang Mai, University, 239 Huay Kaew Road, Suthep, Muang, 50200, Chiang Mai (Thailand)

2009-07-23

211

Strongly enhanced incorporation of oxygen into barium titanate based multilayer ceramic capacitors using water vapor  

SciTech Connect

The reoxidation of sintered BaTiO{sub 3}-based multilayer ceramic capacitors (MLCCs) is currently an empirically determined, but poorly understood, procedure. In this work, the incorporation of oxygen into BaTiO{sub 3}-based MLCCs has been studied by means of isotope exchange annealing ({sup 18}O{sub 2}/{sup 16}O{sub 2}, {sup 1}H{sub 2}{sup 18}O/{sup 1}H{sub 2}{sup 16}O or {sup 2}H{sub 2}{sup 16}O/{sup 1}H{sub 2}{sup 16}O) and subsequent determination of the isotope profiles in the solid by secondary ion mass spectrometry. Oxygen isotope profiles in the barium titanate dielectric can be described by a bulk diffusion coefficient D* and a surface exchange coefficient k*. The values obtained for k* indicate that oxygen incorporation from H{sub 2}O is much faster than from dry O{sub 2}; it thus plays the key role in the reoxidation process.

Kessel, M.; De Souza, R. A.; Martin, M. [Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen (Germany); Yoo, H.-I. [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

2010-07-12

212

Dielectric and Ferroelectric Behavior of Bismuth-Doped Barium Titanate Ceramic Prepared by Microwave Sintering  

NASA Astrophysics Data System (ADS)

Bismuth-doped barium titanate ceramics with the general formula Ba1-x Bi2x/3TiO3 (x = 0.0, 0.01, 0.025, 0.05) have been prepared by the solid state reaction technique. The phase formation and structural property of all compositions have been studied by x-ray diffraction (XRD) pattern and Rietveld refinement. XRD pattern reports the single phase tetragonal crystal system with space group of P4mm. All compositions have been sintered at 1100°C in a microwave furnace for 30 min. The variation of dielectric constant with respect to temperature and frequency was studied and it was found that the dielectric constant decreases whereas transition temperature increased with the increase in Bi content. The diffusivity parameter was calculated by the modified Curie-Weiss law and the diffusivity increased with the increase in Bi content. The ferroelectric property was studied by the P-E hysteresis loop and it was observed that the saturation polarization decreased, but the coercive field increased with Bi content. The optical band gap was calculated from UV-Visible spectroscopy and found to decrease with Bi content.

Mahapatra, A.; Parida, S.; Sarangi, S.; Badapanda, T.

2014-12-01

213

CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: Enhanced mechanical behaviour of lead zirconate titanate piezoelectric composites incorporating zinc oxide nanowhiskers  

NASA Astrophysics Data System (ADS)

This paper reports that the lead zirconate titanate (PZT) piezoelectric composites incorporating zinc oxide nanowhiskers (ZnOw) were prepared by the conventional solid state processing. The whisker-dispersed PZT composites (PZT/ZnOw) presented a significant enhancement in the mechanical properties such as Young's modulus, tensile strength and compressive strength. Especially, the compressive strength increased from 153 MPa for the PZT to 228 MPa for the PZT/ZnOw composites. The reinforcement mechanism in strength of the composites was discussed. The mechanical quality factors of the PZT/ZnOw composites increased considerably, while the piezoelectric constants and electromechanical coupling coefficient decreased slightly. The composites with good electrical and excellent mechanical properties are promising for further applications.

Lin, Hai-Bo; Cao, Mao-Sheng; Yuan, Jie; Wang, Da-Wei; Zhao, Quan-Liang; Wang, Fu-Chi

2008-11-01

214

Composition Design Rule for High Piezoelectric Voltage Coefficient in (K0.5Na0.5)NbO3 Based Pb-Free Ceramics  

NASA Astrophysics Data System (ADS)

In this manuscript, the phase transition factor (Ft) was suggested as a design rule for high piezoelectric voltage coefficient in (K0.5Na0.5)NbO3 (KNN) based ceramics. The Ft consisted of the tolerance factor and electronegativity difference. High piezoelectric voltage coefficient was observed when the doping ratio for the starting point of phase transition (x*) was higher than 0.04 in KNN based ceramics. At the range of Ft < -0.01, x* was higher than 0.04 and high g33 value (>30 mV·m/N) was observed in KNN based ceramics.

Ahn, Cheol-Woo; Han, Guifang; Ryu, Jungho; Yoon, Woon-Ha; Choi, Jong-Jin; Hahn, Byung-Dong; Kim, Jong-Woo; Choi, Joon-Hwan; Park, Dong-Soo

2012-09-01

215

Calculations of the effective properties of 1-3 type piezoelectric composites with various rod\\/fibre orientations  

Microsoft Academic Search

The effective properties of non-conventional 1-3 type piezoelectric composites with various orientations of lead zirconate titanate rods\\/fibres aligned in an epoxy matrix are calculated using the recently developed Green's function technique. The effects of the volume fraction and (polarization) orientation of the ceramic rods\\/fibres on the effective piezoelectric properties are presented in detail. The theoretical predictions demonstrate the interesting behaviour

Ce-Wen Nan; Li Liu; Dong Guo; Longtu Li

2000-01-01

216

Production of continuous piezoelectric ceramic fibers for smart materials and active control devices  

NASA Astrophysics Data System (ADS)

Advanced Cerametrics Inc. has conceived of and developed the Viscous-Suspension-Spinning Process (VSSP) to produce continuous fine filaments of nearly any powdered ceramic materials. VSSP lead zirconate titanate (PZT) fiber tows with 100 and 790 filaments have been spun in continuous lengths exceeding 1700 meters. Sintered PZT filaments typically are 10 - 25 microns in diameter and have moderate flexibility. Prior to carrier burnout and sintering, VSSP PZT fibers can be formed into 2D and 3D shapes using conventional textile and composite forming processes. While the extension of PZT is on the order of 20 microns per linear inch, a woven, wound or braided structure can contain very long lengths of PZT fiber and generate comparatively large output strokes from relatively small volumes. These structures are intended for applications such as bipolar actuators for fiber optic assembly and repair, vibration and noise damping for aircraft, rotorcraft, automobiles and home applications, vibration generators and ultrasonic transducers for medical and industrial imaging. Fiber and component cost savings over current technologies, such as the `dice-and-fill' method for transducer production, and the range of unique structures possible with continuous VSSP PZT fiber are discussed. Recent results have yielded 1-3 type composites (25 vol% PZT) with d33 equals 340 pC/N, K equals 470, and g33 equals 80 mV/N, kt equals 0.54, kp equals 0.19, dh equals 50.1pC/N and gh equals 13 mV/N.

French, Jonathan D.; Weitz, Gregory E.; Luke, John E.; Cass, Richard B.; Jadidian, Bahram; Bhargava, Parag; Safari, Ahmad

1997-05-01

217

Bright upconversion luminescence and increased Tc in CaBi2Ta2O9:Er high temperature piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

Er3+ doped CaBi2Ta2O9 (CBT) bismuth layered-structure high temperature piezoelectric ceramics were synthesized by the traditional solid state method. The upconversion (UC) emission properties of Er3+ doped CBT ceramics were investigated as a function of Er3+ concentration and incident pump power. A bright green upconverted emission was obtained under excitation 980 nm at room temperature. The observed strong green and weak red emission bands corresponded to the transitions from 4S3/2 and 4F9/2 to 4I15/2, respectively. The dependence of UC emission intensity on pumping power indicated that a three-photon process was involved in UC emissions. Studies of dielectric with temperature have also been carried out. Introduction of Er increased the Curie temperature of CBT, thus, making this ceramic suitable for sensor applications at higher temperatures. Because of its strong up-converted emission and increased Tc, the multifunctional high temperature piezoelectric ceramic may be useful in high temperature sensor, fluorescence thermometry, and optical-electro integration applications.

Peng, Dengfeng; Wang, Xusheng; Xu, Chaonan; Yao, Xi; Lin, Jian; Sun, Tiantuo

2012-05-01

218

Dielectric and piezoelectric properties of the KNN ceramic compound doped with Li, La and Ta  

NASA Astrophysics Data System (ADS)

With the purpose of improving the dielectric and piezoelectric properties of (K0.5Na0.5)NbO3 (KNN), a multiple doping strategy was tested in this research. Piezoceramics with composition [(K0.5Na0.5)0.94Li0.06]0.97La0.01(Nb0.9Ta0.1)O3 were prepared by the traditional ceramic method. The calcined powders were sintered in their own atmosphere at 1,100 °C for 1.0, 1.5 and 2.5 h. X-ray diffraction analysis showed that the Li+, La3+ and Ta5+ cations diffuse into the KNN structure to form a perovskite-structured solid solution. For 1 h sintering time, a dominant orthorhombic phase is obtained, whereas for the longer times, the dominant phase was tetragonal. The presence of a tetragonal tungsten-bronze minority second phase is confirmed. Scanning electron micrographs show rectangular-shaped grains with a mean size of 1.1 ± 0.2 ?m. The existence of pores and traces of a liquid phase favoring grain growth and homogeneity is also observed. Experimental results show an enhancement of the permittivity associated with the enlargement of the c parameter of the cell that increases with sintering time. Li+ incorporation into the structure is made evident by its transition temperature at 400 °C different from those of KNNLaTi (81-110 °C) and KNNLaTa (340 °C). An analysis of the phase transition of the samples indicates a normal rather than a diffuse transition. The electromechanical parameters k p, Q m, ? p, s 11, d 31 and g 31 are determined and compared to those of commercial PZT ceramics.

Fuentes, J.; Portelles, J.; Durruthy-Rodríguez, M. D.; H'Mok, H.; Raymond, O.; Heiras, J.; Cruz, M. P.; Siqueiros, J. M.

2015-02-01

219

Combinatorial processing libraries for bulk BiFeO3-PbTiO3 piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

A high throughput approach for generating combinatorial libraries with varying processing conditions for bulk ceramics has been developed. This approach utilized the linear temperature gradient in a tube furnace to screen a whole temperature range for optimized preparation. With this approach, the processing of 0.98[0.6BiFeO3-0.4PbTiO3]-0.02Pb(Mg1/3Nb2/3)O3 ceramic powders and pellets for high-temperature piezoelectric applications was demonstrated to identify the best synthesis conditions for phase purity. The dielectric property measurement on the as-processed solid solution ceramics confirmed the high Curie temperature and the improved loss tangent with the Pb(Mg1/3Nb2/3)O3 doping.

Hu, W.; Tan, X.; Rajan, K.

2010-05-01

220

Effect of Excess Lead and Bismuth Content on the Electrical Properties of High-Temperature Bismuth Scandium Lead Titanate Ceramics  

NASA Technical Reports Server (NTRS)

Aeronautic and aerospace applications require piezoelectric materials that can operate at high temperatures. The air-breathing aeronautic engines can use piezoelectric actuators for active combustion control for fuel modulation to mitigate thermo-acoustic instabilities and/or gas flow control to improve efficiency. The principal challenge for the insertion of piezoelectric materials is their limitation for upper use temperature and this limitation is due low Curie temperature and increasing conductivity. We investigated processing, microstructure and property relationship of (1-x)BiScO3-(x)PbTiO3 (BS-PT) composition as a promising high temperature piezoelectric. The effect of excess Pb and Bi and their partitioning in grain boundaries were studied using impedance spectroscopy, ferroelectric, and piezoelectric measurement techniques. Excess Pb addition increased the grain boundary conduction and the grain boundary area (average grain size was 24.8 m, and 1.3 m for compositions with 0at.% and 5at.% excess Pb, respectively) resulting in ceramics with higher AC conductivity (tan d= 0.9 and 1.7 for 0at.% and 5at.% excess Pb at 350 C and at 10kHz) that were not resistive enough to pole. Excess Bi addition increased the resistivity (rho= 4.1x10(exp 10) Omega cm and 19.6 x10(exp 10) Omega.cm for compositions with 0at.% and 5at.% excess Bi, respectively), improved poling, and increased the piezoelectric coefficient from 137 to 197 pC/N for 5at.% excess Bi addition. In addition, loss tangent decreased more than one order of magnitude at elevated temperatures (greater than 300 C). For all compositions the activation energy of the conducting species was similar (approximately equal to 0.35-0.40 eV) and indicated electronic conduction.

Sehirlioglu, Alp; Sayir, Ali

2008-01-01

221

Adaptive hybrid control for linear piezoelectric ceramic motor drive using diagonal recurrent CMAC network.  

PubMed

This paper presents an adaptive hybrid control system using a diagonal recurrent cerebellar-model-articulation-computer (DRCMAC) network to control a linear piezoelectric ceramic motor (LPCM) driven by a two-inductance two-capacitance (LLCC) resonant inverter. Since the dynamic characteristics and motor parameters of the LPCM are highly nonlinear and time varying, an adaptive hybrid control system is therefore designed based on a hypothetical dynamic model to achieve high-precision position control. The architecture of DRCMAC network is a modified model of a cerebellar-model-articulation-computer (CMAC) network to attain a small number of receptive-fields. The novel idea of this study is that it employs the concept of diagonal recurrent neural network (DRNN) in order to capture the system dynamics and convert the static CMAC into a dynamic one. This adaptive hybrid control system is composed of two parts. One is a DRCMAC network controller that is used to mimic a conventional computed torque control law due to unknown system dynamics, and the other is a compensated controller with bound estimation algorithm that is utilized to recover the residual approximation error for guaranteeing the stable characteristic. The effectiveness of the proposed driving circuit and control system is verified with hardware experiments under the occurrence of uncertainties. In addition, the advantages of the proposed control scheme are indicated in comparison with a traditional integral-proportional (IP) position control system. PMID:15565776

Wai, Rong-Jong; Lin, Chih-Min; Peng, Ya-Fu

2004-11-01

222

Recurrent fuzzy neural network control for piezoelectric ceramic linear ultrasonic motor drive.  

PubMed

In this study, a recurrent fuzzy neural network (RFNN) controller is proposed to control a piezoelectric ceramic linear ultrasonic motor (LUSM) drive system to track periodic reference trajectories with robust control performance. First, the structure and operating principle of the LUSM are described in detail. Second, because the dynamic characteristics of the LUSM are nonlinear and the precise dynamic model is difficult to obtain, a RFNN is proposed to control the position of the moving table of the LUSM to achieve high precision position control with robustness. The back propagation algorithm is used to train the RFNN on-line. Moreover, to guarantee the convergence of tracking error for periodic commands tracking, analytical methods based on a discrete-type Lyapunov function are proposed to determine the varied learning rates of the RFNN. Then, the RFNN is implemented in a PC-based computer control system, and the LUSM is driven by a unipolar switching full bridge voltage source inverter using LC resonant technique. Finally, the effectiveness of the RFNN-controlled LUSM drive system is demonstrated by some experimental results. Accurate tracking response and superior dynamic performance can be obtained because of the powerful on-line learning capability of the RFNN controller. Furthermore, the RFNN control system is robust with regard to parameter variations and external disturbances. PMID:11477782

Lin, F J; Wai, R J; Shyu, K K; Liu, T M

2001-07-01

223

Problems with cryogenic operation of piezoelectric bending elements  

NASA Astrophysics Data System (ADS)

Piezoelectric bimorphs constructed from lead titanate-zirconate (PZT) ceramic bonded to a brass sheet have been tested at cryogenic temperatures to determine their suitability for use in a low-temperature micropositioner. Experimental data are presented on bimorph sensitivity (displacement per volt) as a function of the number of temperature cycles. Results indicate that bimorphs of this type cannot be calibrated because of irreversible changes in the bending characteristics that occur while cycling from room temperature to 4 K.

Duffield, C. L.; Moreland, John; Fickett, F. R.

1986-05-01

224

Luminescence properties of barium--gadolinium-titanate ceramics doped with rare-earth ions (Eu3+ and Tb3+).  

PubMed

Barium-gadolinium-titanate (BaGd2 Ti4 O12) powder ceramics doped with rare-earth ions (Eu(3+) and Tb(3+)) were synthesized by a solid-state reaction method. From the X-ray diffraction spectrum, it was observed that Eu(3+) and Tb(3+):BaGd2 Ti4 O12 powder ceramics are crystallized in the form of an orthorhombic structure. Scanning electron microscopy image shows that the particles are agglomerated and the particle size is about 200 nm. Eu(3+) - and Tb(3+) -doped BaGd2 Ti4 O12 powder ceramics were examined by energy dispersive X-ray analysis, Fourier transform infrared spectroscopy, photoluminescence and thermoluminescence (TL) spectra. Emission spectra of Eu(3+)-doped BaGd2 Ti4 O12 powder ceramics showed bright red emission at 613 nm ((5)D0 ?(7)F2) with an excitation wavelength ?(exci) ?= 408 nm ((7)F0 ? (5)D3) and Tb(3+):BaGd2 Ti4 O12 ceramic powder has shown green emission at 534 nm ((5)D4 ? (7)F5) with an excitation wavelength ?(exci) ?= 331 nm (((7)F6 ? (5)D1). TL spectra show that Eu(3+) and Tb(3+) ions affect TL sensitivity. PMID:24616270

Hemasundara Raju, S; Muni Sudhakar, B; Sudhakar Reddy, B; Dhoble, S J; Thyagarajan, K; Nageswara Raju, C

2014-11-01

225

Hydrogen diffusion in Lead Zirconate Titanate and Barium Titanate  

SciTech Connect

Hydrogen is a potential clean-burning, next-generation fuel for vehicle and stationary power. Unfortunately, hydrogen is also well known to have serious materials compatibility issues in metals, polymers, and ceramics. Piezoelectric actuator materials proposed for low-cost, high efficiency high-pressure hydrogen internal combustion engines (HICE) are known to degrade rapidly in hydrogen. This limits their potential use and poses challenges for HICE. Hydrogen-induced degradation of piezoelectrics is also an issue for low-pressure hydrogen passivation in ferroelectric random access memory. Currently, there is a lack of data in the literature on hydrogen species diffusion in piezoelectrics in the temperature range appropriate for the HICE as charged via a gaseous route. We present 1HNMR quantification of the local hydrogen species diffusion within lead zirconate titanate and barium titanate on samples charged by exposure to high-pressure gaseous hydrogen ?32?MPa. Results are discussed in context of theoretically predicted interstitial hydrogen lattice sites and aqueous charging experiments from existing literature.

Alvine, Kyle J.; Vijayakumar, M.; Bowden, Mark E.; Schemer-Kohrn, Alan L.; Pitman, Stan G.

2012-08-28

226

Hydrogen diffusion in lead zirconate titanate and barium titanate  

NASA Astrophysics Data System (ADS)

Hydrogen is a potential clean-burning, next-generation fuel for vehicle and stationary power. Unfortunately, hydrogen is also well known to have serious materials compatibility issues in metals, polymers, and ceramics. Piezoelectric actuator materials proposed for low-cost, high efficiency high-pressure hydrogen internal combustion engines (HICE) are known to degrade rapidly in hydrogen. This limits their potential use and poses challenges for HICE. Hydrogen-induced degradation of piezoelectrics is also an issue for low-pressure hydrogen passivation in ferroelectric random access memory. Currently, there is a lack of data in the literature on hydrogen species diffusion in piezoelectrics in the temperature range appropriate for the HICE as charged via a gaseous route. We present 1HNMR quantification of the local hydrogen species diffusion within lead zirconate titanate and barium titanate on samples charged by exposure to high-pressure gaseous hydrogen ˜32 MPa. Results are discussed in context of theoretically predicted interstitial hydrogen lattice sites and aqueous charging experiments from existing literature.

Alvine, K. J.; Vijayakumar, M.; Bowden, M. E.; Schemer-Kohrn, A. L.; Pitman, S. G.

2012-08-01

227

Fabrication and Piezoelectric Properties of Textured (Bi1/2K1/2)TiO3 Ferroelectric Ceramics  

NASA Astrophysics Data System (ADS)

Textured (Bi1/2K1/2)TiO3 (BKT) ceramics were prepared by a reactive templated grain growth (RTGG) method to improve their piezoelectric properties. Also, a hot-pressing (HP) method was modified on the basis of RTGG method to obtain dense ceramics and promote the grain orientation. The textured BKT ceramics prepared by the RTGG and HP methods exhibited a relatively high orientation factor F of 0.82 and a high density ratio of 95-99%. Scanning electron microscopy (SEM) micrographs of the textured HP-BKT indicated a textured and poreless microstructure. In addition, the resistivity of the textured HP-BKT was 1.73×1013 ?·cm. The piezoelectric strain constant d33 determined by means of resonance and antiresonance method was 125 pC/N for the direction parallel to the sheet-stacking direction of the RTGG process. From the measurement of field-induced stain, the normalized d33* (=Smax/Emax) at 80 kV/cm were 127 and 238 pm/V on the randomly oriented and textured samples (F=0.82) for the (?) direction, respectively.

Nagata, Hajime; Saitoh, Masahiro; Hiruma, Yuji; Takenaka, Tadashi

2010-09-01

228

Piezoelectric Ultrasonic Micromotors  

E-print Network

This report describes development of micro-fabricated piezoelectric ultrasonic motors and bulk-ceramic piezoelectric ultrasonic motors. Ultrasonic motors offer the advantage of low speed, high torque operation without ...

Flynn, Anita M.

1995-06-01

229

Strontium Titanate DC Electric Field Switchable and Tunable Bulk Acoustic Wave Solidly Mounted Resonator  

E-print Network

films, piezoelectric resonators. I. INTRODUCTION Strontium titanate (STO) and barium strontium titanateStrontium Titanate DC Electric Field Switchable and Tunable Bulk Acoustic Wave Solidly Mounted Abstract - A voltage switchable/tunable strontium titanate solidly mounted BAW resonator was implemented

York, Robert A.

230

Ferroelectric, Piezoelectric and Pyroelectric Properties of Sr1+xBi4-xTi4-xTaxO15 Ceramics (x=0-1)  

Microsoft Academic Search

The dielectric, ferroelectric, piezoelectric and pyroelectric properties of bismuth layer-structured ferroelectric (BLSF) Sr1+xBi4-xTi4-xTaxO15 (x=0-1) ceramics were investigated. The Curie temperature of this system is from 540°C to 30°C, and all samples show ferroelectricity at room temperature. From piezoelectric measurements, Sr1.1Bi3.9Ti3.9Ta0.1O15 was found to have the largest piezoelectric coefficient and electromechanical coupling factor of compounds in this system. The thermally stimulated

Minglei Zhao; Chunlei Wang; Weilie Zhong; Jinfeng Wang; Hongcun Chen

2002-01-01

231

The impact of brannerite on the release of plutonium and gadolinium during the corrosion of zirconolite-rich titanate ceramics  

SciTech Connect

Titanate ceramics have been selected as the preferred waste form for the immobilization of excess plutonium. Corrosion tests are underway to try to understand the long-term behavior of this material. In this paper, results from PCT-B static dissolution tests are used to provide an explanation of the observed corrosion behavior of a zirconolite-based ceramic. Two important observations are made. First, Ca is released at a constant rate [7 x 10{sup {minus}5} g/(m{sup 2} day)] in PCT-B tests for up to two years. Second, the release rates for Pu and Gd increase with time (up to two years) in PCT-B tests. The first observation suggests that the ceramics continue to corrode at a low rate for at least two years in PCT-B tests. The second observation suggests that the release rates of Pu and Gd are controlled by some process or processes that do not affect the release rate of other elements. Evidence indicates that this is due to the preferential dissolution of brannerite from the ceramic.

Chamberlain, D. B.; Hash, M. C.; Basco, J. K.; Bakel, A. J.; Metz, C. J.; Wolf, S. F.; Buck, E. C.; Nole, M. K.

2000-03-14

232

Microstructure, dielectric and piezoelectric properties of (Pb1-xSrx)Nb1.96Ti0.05O6 ceramics  

NASA Astrophysics Data System (ADS)

(Pb1-xSrx)Nb1.96Ti0.05O6 with 2 wt% excess PbO (x = 0, 0.02, 0.04, 0.06, 0.08) piezoelectric ceramics with high Curie temperature were fabricated via the conventional solid state reaction method. Effects of Sr2+ amount on crystallite structure, microstructure, dielectric and piezoelectric properties were studied. The substitution of Sr2+ ions for Pb2+ ions is effective to lower sintering temperatures. X-ray diffraction patterns indicate that all ceramics form the single orthorhombic ferroelectric phase. The doping of Sr2+ ions facilitates improving densification of the ceramics. Grain size and lattice parameters of the ceramics vary with the change of the Sr2+ contents. Both Curie temperature and maximum dielectric constant change with increasing the Sr2+ amounts. The dielectric constant data were also studied using the Curie-Weiss law and modified Curie-Weiss law. The ceramic with x = 0.04 possesses excellent piezoelectric and dielectric properties, presenting a high potential to be used in high-temperature applications as piezoelectric transducers.

Yuan, Jing-jing; Chen, Xiao-ming; Zhou, Jian-ping; Liu, Peng

2014-09-01

233

ceramic  

NASA Astrophysics Data System (ADS)

We report that magnetism, especially ferromagnetism, can be induced in a nonmagnetic ferroelectric oxide such as barium titanate (BaTiO3) with choosing of suitable dopants. High-density polycrystalline sample of BaTi0.9Hf0.05Co0.05O3 was prepared using solid-state sintering route, and the effect of Co and Hf substitution on structural, magnetic and ferroelectric properties of BaTiO3 was studied. The magnetic order obtained in the above sample is of intrinsic in nature. Ferromagnetic behavior shown in the BaTi0.9Hf0.05Co0.05O3 ceramic may be attributed to the effective exchange interactions between oxygen vacancies and Co ions. BaTi0.9Hf0.05Co0.05O3 ceramic has also shown ferroelectric (lossy type) behavior.

Das, S. K.; Mishra, R. N.; Roul, B. K.

2014-09-01

234

Enhanced High Temperature Piezoelectrics Based on BiScO3-PbTiO3 Ceramics  

NASA Technical Reports Server (NTRS)

High-temperature piezoelectrics are a key technology for aeronautics and aerospace applications such as fuel modulation to increase the engine efficiency and decrease emissions. The principal challenge for the insertion of piezoelectric materials is the limitation on upper use temperature which is due to low Curie-Temperature (TC) and increasing electrical conductivity. BiScO3-PbTiO3 (BS-PT) system is a promising candidate for improving the operating temperature for piezoelectric actuators due to its high TC (greater than 400 C). Bi2O3 was shown to be a good sintering aid for liquid phase sintering resulting in reduced grain size and increased resistivity. Zr doped and liquid phase sintered BS-PT ceramics exhibited saturated and square hysteresis loops with enhanced remenant polarization (37 microC per square centimeter) and coercive field (14 kV/cm). BS-PT doped with Mn showed enhanced field induced strain (0.27% at 50kV/cm). All the numbers indicated in parenthesis were collected at 100 C.

Sehirlioglu, Alp; Sayir, Ali; Dynys, Fred

2009-01-01

235

Barium strontium titanate and non-ferroelectric oxide ceramic composites for use in phased array antennas  

Microsoft Academic Search

A ceramic ferroelectric phase shifting device has been demonstrated using Ba1?xSrxTiO3 (BSTO) ceramics. As part of an effort to optimize the device performance, various composites of BSTO and other nonelectrically active oxide ceramics have been formulated. In general the composites have reduced dielectric constants, ??, where ? = ??-i?? and reduced loss tangents, tan ?, compared to BSTO. The low

L. C. Sengupta; S. Stowell; E. Ngo; M. E. Oday; R. Lancto

1995-01-01

236

Effects of Fe2O3 Additive on the Structure and Piezoelectric Properties of PZT-PFW-PMN Ceramics  

NASA Astrophysics Data System (ADS)

Quaternary piezoelectric ceramics 0.90Pb0.95Sr0.05(Zr0.52Ti0.48)O3-0.03Pb(Fe2/3W1/3)O3-0.07Pb(Mn1/3Nb2/3)O3 (PZT-PFW-PMN) + 0.2 wt.% CeO2 + x wt.% Fe2O3 ( x = 0.0 to 0.20) were prepared by the conventional solid-state method. The effects of Fe2O3 addition on the structure and electrical properties of the system were systematically investigated. The results revealed that the phase structure of all samples was tetragonal phase and the piezoelectric and dielectric properties were significantly promoted with increasing Fe2O3 addition. The coercive field E C and internal bias field E i were found to increase with increasing Fe2O3 content. As a result, addition of 0.05 wt.% Fe2O3 for this system resulted in excellent electrical properties, with the following parameter values: Q m = 1839, K p = 0.61, d 33 = 382 pC/N, ? r = 1823, tan ? = 0.0054, P r = 19.26 ?C/cm2, E C = 13.28 kV/cm, and E i = 0.76 kV/cm. The results indicate that the Fe2O3-modified PZT-PFW-PMN ceramics exhibited favorable properties and could be good candidates for use in high-power piezoelectric transformer applications.

Zong, Ximei; Yang, Zupei

2015-01-01

237

Ferroelectric, piezoelectric, and dielectric properties of BiScO{sub 3}-PbTiO{sub 3}-Pb(Cd{sub 1/3}Nb{sub 2/3})O{sub 3} ternary high temperature piezoelectric ceramics  

SciTech Connect

(0.95-x)BiScO{sub 3}-xPbTiO{sub 3}-0.05Pb(Cd{sub 1/3}Nb{sub 2/3})O{sub 3} (BS-xPT-PCN) high temperature piezoelectric ceramics near the morphotropic phase boundary (MPB) have been synthesized by traditional solid-state reaction methods. The microstructural morphology, phase structure, and electrical properties of BS-xPT-PCN ceramics were investigated in detail. X-ray diffraction analysis indicated BS-xPT-PCN ceramics have a pure perovskite structure. The coexistence of rhombohedral and tetragonal phases at MPB composition enhanced the polarizability by the coupling between two dynamically equivalent energy states, resulting in the improved piezoelectric and ferroelectric properties at MPB vicinity. The BS-xPT-PCN (x = 0.60) ceramics possess the optimal piezoelectric and ferroelectric properties with d{sub 33} = 505pC/N, k{sub p} = 55.9%, k{sub t} = 36.5%, strain = 0.23% (under the electric field 37.5 kV/cm), and P{sub r} = 39.7 {mu}C/cm{sup 2}. High temperature dielectric behaviors showed diffuse phase transition in BS-xPT-PCN ceramics. The Curie temperature T{sub c} was found to increase from 371 Degree-Sign C to 414 Degree-Sign C with x increasing from 0.58 to 0.62. All these results together with the good thermal stabilities make the BS-xPT-PCN ceramics promising candidates for high temperature piezoelectric applications.

Zhao Tianlong [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Chen Jianguo; Dong Shuxiang [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Wang Chunming [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Yu Yang [Faculty of Physics and Electronic Technology, Hubei University, Wuhan 430062 (China)

2013-07-14

238

Preparation and Characterization of Lead-free Piezoelectric Ceramics Qiang Chen1,a  

E-print Network

.04)O3 (KNL-NTS) were successfully fabricated by traditional ceramics processing. The effects, pure KNN ceramics are difficult to fully densify by ordinary sintering methods due to the high been widely used to prepare KNN-based ceramics by conventional solid state sintering methods [7

Volinsky, Alex A.

239

BiFeO3-doped (Na0.5K0.5)NbO3 lead-free piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

Lead-free piezoelectric ceramics (1-x)(Na0.5K0.5)NbO3-xBiFeO3 (x=0~0.07) were synthesized by the solid-state reaction. Differential scanning calorimetry (DSC) measurements revealed that an increase in the amount of BiFeO3 dopant resulted in a decrease in the orthorhombic-tetragonal and tetragonal-cubic phase transition temperature of the material. One percent BiFeO3 additive suppressed grain growth, which not only benefits the sintering of ceramics but also enhances the piezoelectric and ferroelectric properties, where d33=145pC/N, kp=0.31, Qm=80, Pr=11.3 ?C cm-2 and Ec=16.5 kV cm-1. As xBF>0.01, both piezoelectric and ferroelectric properties decreased rapidly with an increasing amount of dopant.

Sun, Xueyi; Chen, Jun; Yu, Ranbo; Xing, Xianran; Qiao, Lijie; Liu, Guirong

2008-04-01

240

Measurements of Complex Piezoelectric d33 Constant in Ferroelectric Ceramics under High Electric Field Driving  

Microsoft Academic Search

A measurement system has been designed and constructed which is capable of automatic data collection for complex piezoelectric d33 constant (amplitude and phase), field-induced polarization and switching current under high electric field driving in ferroelectric materials. The system is based on the direct piezoelectric effect and d33 constant can be measured down to about 10 pC\\/N. Using this system, low

Yasuyoshi Saito

1995-01-01

241

Piezoelectric and Ferroelectric Properties of Lead-Free Bi4?xNdxTi2.97V0.03O12 Ceramics  

Microsoft Academic Search

We fabricated lead-free Bi4?xNdxTi2.97V0.03O12 (x = 0.25?1.00; BNdTV-x) ceramics using the conventional solid-state reaction method and investigated their ferroelectric and piezoelectric properties. BNdTV ceramics exhibited the phase transition from orthorhombic to pseudo-tetragonal structure with increasing Nd concentration. At the morphotropic phase boundary of x = 0.85, BNdTV ceramics showed the highest values of Pr (13 ?C\\/cm), kt (17%) and Qm

Chang Won Ahn; Hai Joon Lee; Ill Won Kim; Jae Shin Lee; Won Kyoung Lee

2006-01-01

242

Memory effect of a mechanical anomaly related to ferroelastic domain switching in rhombohedral lead zirconate titanate ceramics  

SciTech Connect

An anomaly in the temperature dependent mechanical properties of a lead zirconate titanate ferroelectric ceramic has been observed by dynamic mechanical analysis. The anomaly, seen as a rise in modulus, accompanied by a decrease in internal friction, occurs in the low-temperature phase below T{sub C}. The temperature of the anomalies varies systematically with the applied forces and the anomaly does exhibit a memory effect. The corresponding static bending deformation, mainly from remnant strain by ferroelastic domain switching, is analyzed, and a critical remnant strain value for triggering the anomaly is obtained. The anomaly is thought to be induced by pinning and depinning of domain walls. The results confirm that the memory effect and the occurrence of the anomaly are controlled by ferroelastic domain switching.

Wang Can; Redfern, Simon A. T.; Daraktchiev, Maren; Harrison, Richard J. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ United Kingdom (United Kingdom)

2006-10-09

243

Piezoelectric and Mechanical Properties of BaBi4Ti4O15/Ba4Ti13O30 Ceramics  

NASA Astrophysics Data System (ADS)

This article presents the piezoelectric and mechanical properties of bismuth layer-structured ferroelectrics (BLSF)-based BaBi4Ti4O15 ceramics incorporating Ba4Ti13O30. The ceramic compositions, (1-x)BaBi4Ti4O15 xBa4Ti13O30 with x=0 100 vol%, are obtained through solid-state reaction processes. The dielectric constant, ?33T/?0, decreases exponentially from 220 to 97 with increasing x from 0 to 66 vol%. The electromechanical coupling factor, k33, decreases from 15 to 7% with increasing x from 0 to 66 vol%. The fracture toughness, KIC, and flexural strength, ?, of the compositions with x?39 vol% are almost identical to those of Ba4Ti13O30. At x?39 vol%, KIC and ? are nearly 15 and 30% larger than those of BaBi4Ti4O15, respectively. Ba4Ti13O30 particles dispersed uniformly in the ceramics are capable of carrying an applied load effectively and lead to further improvements of the mechanical properties.

Nakai, Yasuhiro; Fukuoka, Shuichi

1999-09-01

244

Ceramics  

NASA Astrophysics Data System (ADS)

Perovskite Ba0.999Pr0.001TiO3 ceramics has been prepared through a solid-state reaction method. Dielectric properties of the doped BaTiO3 (barium titanate) ceramics as a function of temperature at frequencies of 1 kHz, 10 kHz, 100 kHz, and 1 MHz are studied and reported here. Analyzing the empirical parameters, it has been shown that the Pr3+ addition up-shifted the temperature of the maximal dielectric constant to 180 (K) at 1 kHz. The value of the dielectric constant at higher frequencies dropped markedly. Such a marked drop in the value of the dielectric constant at higher frequencies can be explained in terms of interfacial polarization. The high dielectric constant at lower frequencies is due to the build-up of charges at the grain-grain boundary interface which is responsible for the large polarization. The ceramic was subjected to Rietveld refinement for quantitative analysis of the microstructure of the material.

Panigrahi, M. R.

2014-09-01

245

Processing and enhanced piezoelectric properties of highly oriented compositionally modified Pb(Zr,Ti)O3 ceramics fabricated by magnetic alignment  

NASA Astrophysics Data System (ADS)

Highly oriented compositionally modified Pb(Zr,Ti)O3 (PZT) ceramics were successfully obtained by slip casting in a high magnetic field. PZT is a well-known superior ceramic with the highest piezoelectric properties, and these properties have been expected to be further improved through crystalline orientation. However, highly oriented PZT ceramics fabricated by slip casting in a high magnetic field have never been reported. We obtained oriented ceramics using compositionally modified PZT with Pb(Ni,Nb)O3, and their Lotgering factor was 0.77. The electromechanical coupling coefficient (k31) increased by 30%, and an extremely high value of 0.44 was achieved for the oriented ceramics.

Miwa, Yasunari; Kawada, Shinichiro; Kimura, Masahiko; Omiya, Suetake; Kubodera, Noriyuki; Ando, Akira; Suzuki, Tohru S.; Uchikoshi, Tetsuo; Sakka, Yoshio

2015-04-01

246

A novel technique for preparation of grain oriented BLSF piezoelectric ceramics  

Microsoft Academic Search

Grain oriented bismuth layer-structured ferroelectrics (BLSFs) ceramics CaBi4Ti3.95V0.05O15 were prepared by screen-printing method. The particle size of starting materials is a very important factor for the grain\\u000a orientation annealed ceramics. Highly textured ceramics can only be obtained by using nanosized TiO2 and the mechanism for grain orientation was proposed. The electrical properties of the textured ceramics showed strongly\\u000a anisotropic. The

Yongxiang Li; Jiangtao Zeng; Xuezhen Jing; Qingrui Yin

2008-01-01

247

Accurate Characterization And Modeling of Piezoelectric And Electrostrictive Ceramics And Single Crystals  

NASA Astrophysics Data System (ADS)

The continuing need for large actuation and a continually increasing variety of applications has seen the use of piezoelectric materials under a growing range of conditions. These include large applied AC fields, DC bias fields, applied stresses as well as a wider range of frequencies and temperatures. Under these conditions the behaviour of the materials becomes non-linear and is not described well by the small signal parameters supplied by material manufacturers. It is therefore necessary to know and understand the behaviour of piezoelectric materials under these conditions. This presentation reviews the work that has been carried out at the Laboratory for Ferroelectric Materials in the Royal Military College of Canada where we have been studying the non-linear properties of piezoelectric and electrostrictive materials by observing their strain, dielectric and elastic behaviour under the various conditions mentioned above.

Mukherjee, Binu

2008-07-01

248

Ultrasonic imaging system using a leaky surface acoustic wave transducer composed of piezoelectric ceramic and fused quartz  

NASA Astrophysics Data System (ADS)

An ultrasonic imaging system is described by using a leaky surface acoustic wave (SAW) transducer composed of a piezoelectric ceramic thin plate/interdigital transducer/fused quartz. It is shown, both numerically and experimentally, that three operation modes of the transducer at a water-solid interface are available. Each of the three modes has a different operation frequency range, corresponding to the leaky SAW velocity. The bulk wave in water as an acoustical coupler between the tansducer and a tested object has a frequency-dependent angle relation; therefore, the acoustic beam steering is easily controlled and flexible in design. The reflection type of C-mode ultrasonic imaging results are demonstrated and are promising for nondestructive testing.

Toda, Kohji; Sawaguchi, Akihiro

1991-01-01

249

The effect of biaxial texture on the effective electromechanical constants of polycrystalline barium titanate and lead titanate thin films  

E-print Network

barium titanate and lead titanate thin films Jennifer L. Ruglovsky a,*, Jiangyu Li b , Kaushik to an enhanced piezoelectric effect for barium titanate films, but not for lead titanate. Twist texturing about for a polycrystalline film. We explore tetragonal 4MM materials, and give specific results for barium titanate and lead

Atwater, Harry

250

Polymorphic structure evolution and large piezoelectric response of lead-free (Ba,Ca)(Zr,Ti)O{sub 3} ceramics  

SciTech Connect

The polymorphic structure evolution of (Ba,Ca)(Zr,Ti)O{sub 3} piezoelectric ceramics was investigated by analysis of the in situ X-ray diffraction and dielectric spectra. The results indicated that a confined orthorhombic (O) phase region induced by the approach of the rhombohedral (R) and tetragonal (T) phases existed in an extremely narrow temperature range of (Ba{sub 0.85}Ca{sub 0.15})(Zr{sub 0.1}Ti{sub 0.9})O{sub 3} composition. The electric properties near the O–T phase boundaries of (Ba{sub 0.95}Ca{sub 0.05})(Zr{sub 0.05}Ti{sub 0.95})O{sub 3} and (Ba{sub 0.85}Ca{sub 0.15})(Zr{sub 0.1}Ti{sub 0.9})O{sub 3} were compared. The results suggested that the confined O phase region is an important factor that contributes to the extremely large piezoelectric response.

Tian, Ye [Key Laboratory for Macromolecular Science of Shaanxi Province, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an 710062, Shaanxi (China); Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, Shaanxi (China); Chao, Xiaolian, E-mail: chaoxl@snnu.edu.cn, E-mail: yangzp@snnu.edu.cn; Wei, Lingling; Liang, Pengfei; Yang, Zupei, E-mail: chaoxl@snnu.edu.cn, E-mail: yangzp@snnu.edu.cn [Key Laboratory for Macromolecular Science of Shaanxi Province, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an 710062, Shaanxi (China); Jin, Li [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, Shaanxi (China)

2014-03-17

251

A ring-shaped piezoelectric transformer operating in the third symmetric extensional vibration mode  

Microsoft Academic Search

In this study, a ring-shaped piezoelectric transformer operating in the third symmetric extensional vibration mode is proposed, and its characteristics are investigated. The transformer consists of a lead zirconate titanate (PZT) ceramic ring with a high mechanical quality factor which has an outer diameter of 12.7mm, an inner diameter of 5.1mm and a thickness of 1.2mm. The transformer is poled

Jun Hui Hu; Hing Leung Li; Helen Lai Wah Chan; Chung Loong Choy

2001-01-01

252

Influence of gallium substitutions on the structure, dielectric and piezoelectric properties of BiScO3-PbTiO3 ceramics  

NASA Astrophysics Data System (ADS)

Ceramics with compositions close to the morphotropic boundary in the (1 - x)Bi(Sc1-yGay)O3-xPbTiO3 system were prepared by the conventional solid-state reaction method. The influence of substituting Ga3+ cations for Sc3+ cations on the structural parameters and the dielectric and piezoelectric properties was studied. It was proved that variations in the relative content of the tetragonal and rhombohedral phases depended on the tolerance-factor t value determined by the B-cation substitutions. The highest values of the piezoelectric coefficient d33 were observed in the compositions with the largest proportion of the tetragonal phase.

Politova, E. D.; Kaleva, G. M.; Mosunov, A. V.; Segalla, A. H.

2014-04-01

253

Simple model for piezoelectric ceramic\\/polymer 1-3 composites used in ultrasonic transducer applications  

Microsoft Academic Search

A theoretical model is presented for combining parameters of 1-3 ultrasonic composite materials in order to predict ultrasonic characteristics such as velocity, acoustic impedance, electromechanical coupling factor, and piezoelectric coefficients. Hence, the model allows the estimation of resonance frequencies of 1-3 composite transducers. This model has been extended to cover more material parameters, and they are compared to experimental results

H. L. W. Chan; JOSEPH UNSWORTH

1989-01-01

254

New design method of piezoelectric transformer considering high-power characteristics of various composition ceramics  

Microsoft Academic Search

Newly developed design method of the piezoelectric transformer for high voltage source is described. In the method, high power characteristics are utilized for estimating the efficiency and the voltages and electric powers at the input and output terminals, and also the capacitance component of the load impedance is considered. The authors already investigated the high power characteristics on many kinds

S. Hirose; N. Takita; S. Takahashi

1998-01-01

255

Local ferroelectric properties in polyvinylidene fluoride/barium lead zirconate titanate nanocomposites: Interface effect  

NASA Astrophysics Data System (ADS)

The local piezoelectric properties of ferroelectric composites consisting of P(VDF-TrFE) copolymer matrix with barium lead zirconate titanate ceramic inclusions were addressed both experimentally using piezoresponse force microscopy technique and theoretically applying the Landau-Ginzburg-Devonshire formalism. A transient region with a width of approximately 40 nm has been found at the interface between the two constituents. It is shown that the piezoresponse in the vicinity of the interface is strongly affected by inhomogeneous stresses originating from an incompatibility of thermal expansion coefficients of PVDF and lead zirconate titanate.

Silibin, M. V.; Solnyshkin, A. V.; Kiselev, D. A.; Morozovska, A. N.; Eliseev, E. A.; Gavrilov, S. A.; Malinkovich, M. D.; Lupascu, D. C.; Shvartsman, V. V.

2013-10-01

256

Pyroelectric behavior and thermally stimulated processes in niobium modified lead zirconate titanate ferroelectric ceramics  

NASA Astrophysics Data System (ADS)

The thermally stimulated processes in niobium modified lead zirconate titanate ferroelectric system are analyzed from the thermally stimulated depolarization current. Different theoretical models are considered to evaluate the i-T experimental data. The results are associated with the space charge, the pyroelectric response, and the electrical conduction mechanism related to the oxygen vacancies. The results for the pyroelectric contribution are discussed considering the niobium concentration.

Peláiz-Barranco, A.; Garcia-Wong, A. C.; González-Abreu, Y.; Guerra, J. D. S.

2013-01-01

257

Fundamental limitation to the magnitude of piezoelectric response of (001)pc textured K0.5Na0.5NbO3 ceramic  

SciTech Connect

(001)pc textured K0.5Na0.5NbO3 (KNN) ceramic was found to exhibit a 65% improvement in the longitudinal piezoelectric response as compared to its random counterpart. Piezoresponse force microscopy study revealed the existence of larger 180 and non-180 domains for textured ceramic as compared to that of the random ceramic. Improvement in piezoresponse by the development of (001)pc texture is discussed in terms of the crystallographic nature of KNN and domain morphology. A comparative analysis performed with a rhombohedral composition suggested that the improvement in longitudinal piezoresponse of polycrystalline ceramics by the development of (001)pc texture is limited by the crystal structure.

Gupta, Shashaank [ORNL] [ORNL; Belianinov, Alex [ORNL] [ORNL; Okatan, Mahmut B [ORNL] [ORNL; Jesse, Stephen [ORNL] [ORNL; Kalinin, Sergei V [ORNL] [ORNL; Priya, Shashaank [Virginia Tech] [Virginia Tech

2014-01-01

258

Ferroelectric, Piezoelectric and Pyroelectric Properties of Sr1+xBi4-xTi4-xTaxO15 Ceramics (x=0-1)  

NASA Astrophysics Data System (ADS)

The dielectric, ferroelectric, piezoelectric and pyroelectric properties of bismuth layer-structured ferroelectric (BLSF) Sr1+xBi4-xTi4-xTaxO15 (x=0-1) ceramics were investigated. The Curie temperature of this system is from 540°C to 30°C, and all samples show ferroelectricity at room temperature. From piezoelectric measurements, Sr1.1Bi3.9Ti3.9Ta0.1O15 was found to have the largest piezoelectric coefficient and electromechanical coupling factor of compounds in this system. The thermally stimulated current measurements showed that Sr1.1Bi3.9Ti3.9Ta0.1O15 also has excellent pyroelectric responses, and the enhancement of pyroelectric properties may partially result from a relatively large temperature-dependent internal electric field which was observed from the polarization-electric field (P-E) hysteresis loops.

Zhao, Minglei; Wang, Chunlei; Zhong, Weilie; Wang, Jinfeng; Chen, Hongcun

2002-03-01

259

High piezoelectricity due to multiphase coexistence in low-temperature sintered (Ba,Ca)(Ti,Sn)O3-CuOx ceramics  

NASA Astrophysics Data System (ADS)

Ultrahigh piezoelectric constant (d33 = 683 pC/N) and converse piezoelectric coefficient (dS/dE = 1257 pm/V) were observed in CuO-doped lead-free (Ba,Ca)(Ti,Sn)O3 ceramics at an optimal composition fabricated by a conventional sintering method at a low temperature 1250 °C. Since all samples showed a pure perovskite structure with coexisting multiphases including cubic, tetragonal, orthorhombic, and rhombohedral phases around two converged triple points, a good compositional stability of high piezoelectricity along with a high d33 and dS/dE over 600 pC/N and 1000 pm/V was achieved within a wide compositional region (1.0 ? x ? 3.0) regardless of the CuO content (x).

Zhou, Peng-Fei; Zhang, Bo-Ping; Zhao, Lei; Zhao, Xiao-Kun; Zhu, Li-Feng; Cheng, Li-Qian; Li, Jing-Feng

2013-10-01

260

A procedure for the efficient selection of piezoelectric ceramics constituting high-power ultrasonic transducers  

Microsoft Academic Search

The most characteristic narrow-band transducer structure for high-power ultrasonic applications is the well known piezoelectric sandwich which is reminiscent of the Langevin transducer. Such structure is generally used jointly with other components in the construction of industrial high-power transducers.One of the main objectives in the design and construction of such high-power transducers is to minimize energy losses. To that purpose

D. Chacón; G. Rodr?´guez-Corral; L. Gaete-Garretón; E. Riera-Franco de Sarabia; J. A. Gallego-Juárez

2006-01-01

261

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

PubMed

In this study, nonstoichiometric (Na(0.5)K(0.5))(0.97)(Nb(0.96)Sb(0.04))O(3) ceramics were fabricated and their dielectric and piezoelectric properties were investigated according to the CeO(2) addition. In this ceramic composition, CeO(2) addition improved sinterability, electromechanical coupling factor k(p), mechanical quality factor Q(m), piezoelectric constant d(33), and g(33). At the sintering temperature of 1100°C, for the 0.2wt% CeO(2) added specimen, the optimum values of density = 4.359 g/cm(3), k(p) = 0.443, Q(m) = 588, ?(r) = 444, d(33) = 159 pC/N, and g(33) = 35 × 10(-3) V·m/N, were obtained. A piezoelectric energy harvesting device using 0.2 wt% CeO(2)- added lead-free (K(0.5)Na(0.5))(0.97)(Nb(0.96)Sb(0.04))O(3) ceramics and a rectifying circuit for energy harvesting were fabricated and their electrical characteristics were investigated. Under an external vibration acceleration of 0.7 g, when the mass, the frequency of vibration generator, and matching load resistance were 2.4 g, 70 Hz, and 721 ?, respectively, output voltage and power of piezoelectric harvesting device indicated the optimum values of 24.6 mV(rms) and 0.839 ?W, respectively-suitable for application as the electric power source of a ubiquitous sensor network (USN) sensor node. PMID:21937318

Oh, Youngkwang; Noh, Jungrae; Yoo, Juhyun; Kang, Jinhee; Hwang, Larkhoon; Hong, Jaeil

2011-09-01

262

Piezoelectric properties and structural characterization of (Na,Bi)Bi2Ta2O9 ceramics with bismuth layer-structure  

Microsoft Academic Search

The piezoelectric properties of bismuth layer-structured ferroelectrics Na0.5-xBi0.5+x3\\/Bi2Ta2O9 (NBT(x)) dense ceramics were investigated, and the crystal structure of synthesized NBT(x) powders was analyzed by the Rietveld method. NBT(x) powder and ceramics were prepared by conventional synthesis method. NBT(x) powder for x = 0 and x = 0.1 was confirmed to be single phase of BLSFs (m = 2) by x-ray

R. Aoyagi; M. Matsushita; K. Komagata; H. Takeda; S. Okamura; T. Shiosaki

2002-01-01

263

Application of gel-casting to the fabrication of 1-3 piezoelectric ceramic-polymer composites for high-frequency ultrasound devices  

NASA Astrophysics Data System (ADS)

A modified gel-casting technique was used to fabricate a 1-3 piezoelectric ceramic/polymer composite substrate formed by irregular-shaped pillar arrays of small dimensions and kerfs. This technique involves the polymerization of aqueous piezoelectric (PZT) suspensions with added water-soluble epoxy resin and polyamine-based hardener that lead to high strength, high density and resilient ceramic bodies. Soft micromoulding was used to shape the ceramic segments, and micropillars with lateral features down to 4 µm and height-to-width aspect ratios of ˜10 were achieved. The composite exhibited a clear thickness resonance mode at approximately 70 MHz and a keff ˜ 0.51, demonstrating that the ceramic micropillars possess good electrical properties. Furthermore, gel-casting allows the fabrication of ceramic structures with non-conventional shapes; hence, device design is not limited by the standard fabrication methods. This is of particular benefit for high-frequency transducers where the critical design dimensions are reduced.

García-Gancedo, L.; Olhero, S. M.; Alves, F. J.; Ferreira, J. M. F.; Demoré, C. E. M.; Cochran, S.; Button, T. W.

2012-12-01

264

Processing of Piezoelectric (Li,Na,K)NbO3 Porous Ceramics and (Li,Na,K)NbO3/KNbO3 Composites  

NASA Astrophysics Data System (ADS)

Porous Li0.06(Na0.5K0.5)0.94NbO3 (LNKN-6) ceramics with different pore volumes have been prepared using preceramic powder and phenol resin fiber (KynolTM) as a pore former. It was confirmed that the porous ceramics synthesized by the “two-stage firing method” suppressed the loss of alkali elements from the porous body during heat treatment. The porous LNKN-6 ceramics were then converted to LNKN-6/KNbO3 composites through soaking and heat treatment using a sol-gel precursor source composed of KNbO3 to form 3-3-type composites. The microstructure, dielectric, and piezoelectric properties of the porous LNKN-6 ceramics and LNKN-6/KNbO3 composites were characterized and compared. The LNKN-6/KNbO3 composites had a hollow structure whose pores in the region near the surface were filled and coated with KNbO3 precipitates; however, a large amount of residual air was trapped in the pores inside the composites. As a result, the LNKN-6/KNbO3 composites fabricated using 30 vol % KynolTM showed an enhanced piezoelectric voltage output coefficient (g33) of 63.0× 10-3 V\\cdotm/N, compared with monolithic LNKN-6 ceramics having a g33 of 30.2× 10-3 V\\cdotm/N.

Kakimoto, Ken-ichi; Imura, Tomoya; Fukui, Yasuchika; Kuno, Masami; Yamagiwa, Katsuya; Mitsuoka, Takeshi; Ohbayashi, Kazushige

2007-10-01

265

Grain size effect on the nonlinear dielectric properties of barium titanate ceramics  

SciTech Connect

The nonlinear dielectric properties of dense BaTiO{sub 3} ceramics with grain size of 1 {mu}m-90 nm were investigated. In the finest ceramics, the permittivity reduces below 1000 and a remarkable nonhysteretic linear dc-tunability [{epsilon}(E)] is obtained at high field, above 40 kV/cm. The observed behavior was explained by considering the nanostructured ceramic as a composite formed by ferroelectric grains, whose nonlinearity is reducing, and by low-permittivity nonferroelectric grain boundaries, whose volume fraction increases when decreasing the grain size. Reducing the grain size in ferroelectric dense materials is an alternative route to accomplish the application requirements: nonhysteretic tunability and permittivity below 1000.

Curecheriu, Lavinia; Mitoseriu, Liliana [Department of Physics, Alexandru Ioan Cuza University, Bv. Carol I No. 11, Iasi 700506 (Romania); Buscaglia, Maria Teresa; Buscaglia, Vincenzo [Institute of Energetics and Interphases (IENI)-CNR, Via De Marini No. 6, I-16149 Genoa (Italy); Zhao, Zhe [Department of Materials and Environmental Chemistry, University of Stockholm, SE-10691 Stockholm (Sweden)

2010-12-13

266

Piezoelectric and pyroelectric properties of calcium-modified and grain-oriented (NaBi)1\\/2Bi4Ti4O15 ceramics  

Microsoft Academic Search

Grain orientation effects of (NaBi)(l-x)\\/2CaxBi4Ti4O15 (NCBT-100x) ceramics, which belong to a bismuth layer-structured ferroelectric (BLSF) family, are studied using the hot-forging (H.F.) method on the piezoelectric and pyroelectric properties. The dielectric constant ?s is small and almost constant at the wide range of composition (x = 0tox = 1). The Curie temperature, Tc, increases as the Ca concentration increases. The

T. Takenaka; K. Sakata

1989-01-01

267

High-Power Piezoelectric Characteristics of Bi4Ti3O12-SrBi4Ti4O15-Based Ferroelectric Ceramics  

NASA Astrophysics Data System (ADS)

The high-power piezoelectric characteristics of lead-free piezoelectric ceramics based on a mixed bismuth layer-structured ferroelectric, Bi4Ti3O12-SrBi4Ti4O15 (abbreviated as BIT-SBTi) were studied. In addition, MnCO3-doped BIT-SBTi (abbreviated as BIT-SBTi + Mn x wt %) were prepared to improve their high-power piezoelectric properties such as the mechanical quality factor Qm. In the case of pure BIT-SBTi, its vibration velocity v0-p at 5 V/mm field is 1.5 m/s. The v0-p values of the BIT-SBTi + Mn 0.2 and 0.4 wt % ceramics were above 2.0 m/s at 5 V/mm. Also, we observed that the mechanical quality factor Qm at a large amplitude of BIT-SBTi + Mn 0.4 wt % was maintained higher than 4000 at v0-p of 2.0 m/s. The high-power characteristics of BIT-SBTi + Mn x wt % were superior to those of hard Pb(Zr,Ti)O3 (abbreviated as PZT) at a vibration velocity v0-p>1.0 m/s. Therefore, Mn-doped BIT-SBTi-based ceramics are a promising candidate for lead-free high-power applications.

Noumura, Yoji; Hiruma, Yuji; Nagata, Hajime; Takenaka, Tadashi

2010-09-01

268

High-Power Piezoelectric Characteristics at Continuous Driving of Bi4Ti3O12-SrBi4Ti4O15-Based Ferroelectric Ceramics  

NASA Astrophysics Data System (ADS)

The high-power piezoelectric characteristics at continuous driving were studied on lead-free piezoelectric ceramics of a mixed bismuth layer-structured ferroelectric, Bi4Ti3O12-SrBi4Ti4O15 (abbreviated as BIT-SBTi) with MnCO3-doping (abbreviated as BIT-SBTi + Mn x wt %). MnCO3-doping to BIT-SBTi can improve its high-power piezoelectric properties such as the mechanical quality factor Qm. The vibration velocity, v0-p, of the BIT-SBTi + Mn 0.2 wt % ceramics was above 2.0 m/s at 5 V/mm in the case of short- and long-time driving. Also, we observed that the resonance frequency change and temperature on the sample surface at a long-time driving for BIT-SBTi + Mn 0.2 wt % were less than 1.0% and 50 °C at v0-p of 2.0 m/s, respectively. The high-power characteristics of BIT-SBTi + Mn x wt % were superior to those of hard Pb(Zr,Ti)O3 (abbreviated as PZT) at a vibration velocity v0-p > 1.0 m/s. Therefore, Mn-doped BIT-SBTi-based ceramics are a promising candidate for lead-free high-power applications requiring frequency stability and long-time driving.

Noumura, Yoji; Hiruma, Yuji; Nagata, Hajime; Takenaka, Tadashi

2011-07-01

269

Piezoelectric and dielectric properties of Sn-doped (Na0.5K0.5)NbO3 ceramics processed under low oxygen partial pressure atmosphere  

NASA Astrophysics Data System (ADS)

Sn-doped (Na0.5K0.5)NbO3 (Sn-NKN) ceramics fired under various oxygen partial pressure (pO2) conditions have been investigated and discussed in terms of bulk piezoelectric and dielectric properties. X-ray diffraction measurements and Rayleigh analysis indicate that the substitution site of the Sn cations depend on the pO2 atmosphere in the firing process. For pO2 higher than 1.0 × 10-10 atm, Sn cations mainly substitute as Sn4+ at the B-site of perovskite NKN, whereas Sn2+ A-site substitution is favored under a low-pO2 atmosphere. Low-pO2 fired Sn-NKN ceramics exhibit higher relative permittivity, Curie temperature, and piezoelectric coefficient (d33). Sn2+ at A-site acts as a donor and reduces the p-type carrier concentrations that result from an electronic compensation of metal vacancies created through the high volatility of Na and K suboxides. The higher piezoelectricity and resistivity in low-pO2 fired Sn-NKN ceramics make this material suitable for base-metal cofired devices such as Ni-inner-electrode multilayer capacitors and actuators.

Kobayashi, Keisuke; Doshida, Yutaka; Mizuno, Youichi; Randall, Clive A.

2014-01-01

270

Selective substitution and tetragonality by Co-doping of dysprosium and thulium on dielectric properties of barium titanate ceramics  

NASA Astrophysics Data System (ADS)

Barium titanate (BaTiO3) ceramics co-doped with rare-earth elements were investigated in terms of selective substitution and tetragonality. The dielectrics were designed by addition of various Dy2O3 and Tm2O3 contents, for a total of 1 mol. % concentration, and analyzed in a temperature range from -55°C to 150°C. The dielectric constant of the 0.7 mol. % Dy2O3 and the 0.3 mol. % Tm2O3 co-doped BaTiO3 was 2250, which was about 27% higher than those of specimens doped with 1 mol. % Tm2O3 and 1 mol. % Dy2O3 at room temperature. The tendency of dielectric properties was verified through the changes of lattice parameters and binding energy. The substitution of Dy3+ led to a decrease of tetragonality and grain growth; however, amphoteric substitution caused by the co-doping of Dy2O3 and Tm2O3 compensated for those adverse effects. It can be concluded that the improvement of dielectric properties originated from the increase of the site substitution rate of Dy3+ and Tm3+ ions according to the ionic size the in rare-earth doped BaTiO3 system.

Kim, Jungdae; Kim, Dowan; Kim, Jinseong; Kim, Yong-Nam; Hui, K. N.; Lee, Heesoo

2011-06-01

271

High temperature dielectric relaxation anomaly of Y{sup 3+} and Mn{sup 2+} doped barium strontium titanate ceramics  

SciTech Connect

Relaxation like dielectric anomaly is observed in Y{sup 3+} and Mn{sup 2+} doped barium strontium titanate ceramics when the temperature is over 450?K. Apart from the conventional dielectric relaxation analysis method with Debye or modified Debye equations, which is hard to give exact temperature dependence of the relaxation process, dielectric response in the form of complex impedance, assisted with Cole-Cole impedance model corrected equivalent circuits, is adopted to solve this problem and chase the polarization mechanism in this paper. Through this method, an excellent description to temperature dependence of the dielectric relaxation anomaly and its dominated factors are achieved. Further analysis reveals that the exponential decay of the Cole distribution parameter n with temperature is confirmed to be induced by the microscopic lattice distortion due to ions doping and the interaction between the defects. At last, a clear sight to polarization mechanism containing both the intrinsic dipolar polarization and extrinsic distributed oxygen vacancies hopping response under different temperature is obtained.

Yan, Shiguang; Mao, Chaoliang, E-mail: maochaoliang@mail.sic.ac.cn, E-mail: xldong@mail.sic.ac.cn; Wang, Genshui; Yao, Chunhua; Cao, Fei; Dong, Xianlin, E-mail: maochaoliang@mail.sic.ac.cn, E-mail: xldong@mail.sic.ac.cn [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China)

2014-10-14

272

Robust polarization and strain behavior of Sm-modified BiFeO3 piezoelectric ceramics.  

PubMed

The route to phase-pure BiFeO3 (BFO) ceramics with excellent ferroelectric and electromechanical properties is severely impeded by difficulties associated with the perovskite phase stability during synthesis. This has meant that dopants and solid solutions with BFO have been investigated as a means of not only improving the functional properties, but also of improving the perovskite phase formation of BFO-based ceramics. The present work focuses on Sm-modified BFO ceramics of composition Bi0.88Sm0.12FeO3. The polarization and strain behaviors were investigated as a function of the phase composition, microstructure, and chemical composition. Addition of Sm reduces the susceptibility of the BFO perovskite to phase degradation by Si impurities. Si was observed to react into Sm-rich grains dispersed within the microstructure, with no large increases in the amount of bismuth-parasitic phases, namely Bi25FeO39 and Bi2Fe4O9. These as-prepared ceramics exhibited robust polarization behavior showing maximum remnant polarizations of ~40 to 50 ?C/cm(2). The electric-fieldinduced strain showed an appreciable stability in terms of the driving field frequency with maximum peak-to-peak strains of ~0.3% and a coercive field of ~130 kV/cm. PMID:25585392

Walker, Julian; Budic, Bojan; Bryant, Peter; Kurusingal, Valsala; Sorrell, Charles C; Bencan, Andreja; Rojac, Tadej; Valanoor, Nagarajan

2015-01-01

273

Critical thickness for extrinsic contributions to the dielectric and piezoelectric response in lead zirconate titanate ultrathin films  

NASA Astrophysics Data System (ADS)

Highly (100)-textured Pb(Zr0.53Ti0.47)O3 films (Lotgering factors ?90%) with thicknesses ranging from 20 to 260 nm were grown on platinized Si substrates using sol-gel deposition. Ferroelectric hysteresis, low field dielectric permittivity, and nonlinear dielectric response as well as converse longitudinal piezoelectric response (d33,f) of the ultrathin films were studied at 1 kHz. The measurements revealed the existence of a critical film thickness, ˜50 nm, below which the extrinsic contributions to the dielectric response are almost completely suppressed. Piezoelectric response of the films also showed a significant (˜50%) drop at the same critical thickness. Due to the columnar microstructure of these films the critical dimension of the ferroelectric is represented by the thickness rather than the lateral grain size, where the latter is invariant across the samples. The critical thickness led also to a deviation of the thickness dependence of the dielectric permittivity from the in-series capacitors model frequently representing "interfacial dead layers." The critical size is attributed to significant reduction in domain wall population and/or mobility in films thinner than ˜50 nm.

Bastani, Yaser; Schmitz-Kempen, Thorsten; Roelofs, Andreas; Bassiri-Gharb, Nazanin

2011-01-01

274

Enhanced piezoelectric performance of (0.98-x)Bi(Sc{sub 3/4}In{sub 1/4})O{sub 3}-xPbTiO{sub 3}-0.02Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3} ternary high temperature piezoelectric ceramics  

SciTech Connect

(0.98-x)Bi(Sc{sub 3/4}In{sub 1/4})O{sub 3}-xPbTiO{sub 3}-0.02Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3} (BSI-PT-PZN) high temperature piezoelectric ceramics were prepared by traditional solid-state reaction method. Combining X-ray diffraction results with piezoelectric data, it was found that the morphotropic phase boundary (MPB) occurred at x = 0.575. The piezoelectric constant d{sub 33}, curie temperature T{sub c}, and electromechanical coupling factor k{sub p} of BIS-PT-PZN ceramics with MPB composition were 427 pC/N, 412 Degree-Sign C, and 0.51, respectively. Furthermore, the strain of BIS-PT-PZN ceramics reached up to 0.25% under the electric field of 40 kV/cm. Temperature-dependent electromechanical coupling coefficient for MPB composition was stable from room temperature up to 350 Degree-Sign C. The piezoelectric properties of BIS-PT-PZN ceramics were comparable to that of 0.36BiScO{sub 3}-0.64PbTiO{sub 3} (BS-PT) ceramics, and the piezoelectric constant d{sub 33} of BIS-PT-PZN ceramics was about twice that of our previous reported 0.4Bi(Sc{sub 3/4}In{sub 1/4})O{sub 3}-0.6PbTiO{sub 3} (BSI-PT) ceramics. The reduction in the expensive Sc{sub 2}O{sub 3} content and comparable piezoelectric properties with BS-PT ceramics indicated that BIS-PT-PZN ceramics were promising for commercial applications as high temperature actuators and sensors.

Chen Jianguo [Department of Materials Science and Engineering, College of Engineering, Peking University, Yiheyuan Road No.5, Beijing 100871 (China); School of Materials Science and Engineering, Shanghai University, Yanchang Road No. 149, Shanghai 200072 (China); Zhao Tianlong [Department of Materials Science and Engineering, College of Engineering, Peking University, Yiheyuan Road No.5, Beijing 100871 (China); School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Cheng Jinrong [School of Materials Science and Engineering, Shanghai University, Yanchang Road No. 149, Shanghai 200072 (China); Dong Shuxiang [Department of Materials Science and Engineering, College of Engineering, Peking University, Yiheyuan Road No.5, Beijing 100871 (China)

2013-04-14

275

Combinatorial bulk ceramic magnetoelectric composite libraries of strontium hexaferrite and barium titanate.  

PubMed

Bulk ceramic combinatorial libraries were produced via a novel, high-throughput (HT) process, in the form of polycrystalline strips with a gradient composition along the length of the library. Step gradient ceramic composite libraries with 10 mol % steps of SrFe12O19-BaTiO3 (SrM-BT) were made and characterized using HT methods, as a proof of principle of the combinatorial bulk ceramic process, and sintered via HT thermal processing. It was found that the SrM-BT libraries sintered at 1175 °C had the optimum morphology and density. The compositional, electrical and magnetic properties of this library were analyzed, and it was found that the SrM and BT phases did not react and remained discrete. The combinatorial synthesis method produced a relatively linear variation in composition. The magnetization of the library followed the measured compositions very well, as did the low frequency permittivity values of most compositions in the library. However, with high SrM content of ?80 mol %, the samples became increasingly conductive, and no reliable dielectric measurements could be made. Such conductivity would also greatly inhibit any ferroelectricity and magnetoelectric coupling with these composites with high levels of the SrM hexagonal ferrite. PMID:22676556

Pullar, Robert C

2012-07-01

276

Bright upconversion luminescence and increased Tc in CaBi{sub 2}Ta{sub 2}O{sub 9}:Er high temperature piezoelectric ceramics  

SciTech Connect

Er{sup 3+} doped CaBi{sub 2}Ta{sub 2}O{sub 9} (CBT) bismuth layered-structure high temperature piezoelectric ceramics were synthesized by the traditional solid state method. The upconversion (UC) emission properties of Er{sup 3+} doped CBT ceramics were investigated as a function of Er{sup 3+} concentration and incident pump power. A bright green upconverted emission was obtained under excitation 980 nm at room temperature. The observed strong green and weak red emission bands corresponded to the transitions from {sup 4}S{sub 3/2} and {sup 4}F{sub 9/2} to {sup 4}I{sub 15/2}, respectively. The dependence of UC emission intensity on pumping power indicated that a three-photon process was involved in UC emissions. Studies of dielectric with temperature have also been carried out. Introduction of Er increased the Curie temperature of CBT, thus, making this ceramic suitable for sensor applications at higher temperatures. Because of its strong up-converted emission and increased Tc, the multifunctional high temperature piezoelectric ceramic may be useful in high temperature sensor, fluorescence thermometry, and optical-electro integration applications.

Peng Dengfeng [Functional Materials Research Laboratory, Tongji University, 1239 Siping Road, Shanghai 200092 (China); National Institute of Advanced Industrial Science and Technology, Kyushu, 807-1 Shuku, Tosu, Saga 841-0052 (Japan); Wang Xusheng; Yao Xi [Functional Materials Research Laboratory, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Xu Chaonan [National Institute of Advanced Industrial Science and Technology, Kyushu, 807-1 Shuku, Tosu, Saga 841-0052 (Japan); Lin Jian; Sun Tiantuo [College of Material Science and Engineering, Tongji University, 4800 Cao'an Highway, Shanghai 201804 (China)

2012-05-15

277

Effect of orthorhombic distortion on dielectric and piezoelectric properties of CaBi{sub 4}Ti{sub 4}O{sub 15} ceramics  

SciTech Connect

High temperature bismuth layered piezoelectric and ferroelectric ceramics of CaBi{sub 4}Ti{sub 4}O{sub 15} (CBT) have been prepared using the solid state route. The formation of single phase material with orthorhombic structure was verified from x-ray diffraction and Raman spectroscopy. The orthorhombic distortion present in the CBT ceramic sintered at 1200 deg. C was found to be maximum. A sharp phase transition from ferroelectric to paraelectric was observed in the temperature dependent dielectric studies of all CBT ceramics. The Curie's temperature (T{sub c}=790 deg. C) was found to be independent of measured frequency. The behavior of ac conductivity as a function of frequency (100 Hz-1 MHz) at low temperatures (<500 deg. C) follows the power law and is attributed to hopping conduction. The presence of large orthorhombic distortion in the CBT ceramic sintered at 1200 deg. C results in high dielectric constant, low dielectric loss, and high piezoelectric coefficient (d{sub 33}). The observed results indicate the important role of orthorhombic distortion in determining the improved property of multicomponent ferroelectric material.

Tanwar, Amit; Sreenivas, K.; Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

2009-04-15

278

Thickness dependence of hydrostatic piezoelectric properties of 1–3 piezoelectric composites  

Microsoft Academic Search

Thickness dependence of hydrostatic piezoelectric properties of 1–3 piezoelectric composites was studied. PZT rods with square cross section were used as piezoelectric active components. Epoxy resin was used as matrix. The volume fraction of piezoelectric ceramic was about 25%. The hydrostatic piezoelectric properties dh, gh and hydrostatic figure of merit dh gh are all dependent on the ratio of width

Li Denghua; Yao Xi

1999-01-01

279

Enhanced flexoelectricity through residual ferroelectricity in barium strontium titanate  

NASA Astrophysics Data System (ADS)

Residual ferroelectricity is observed in barium strontium titanate ceramics over 30 °C above the global phase transition temperature, in the same temperature range in which anomalously large flexoelectric coefficients are reported. The application of a strain gradient leads to strain gradient-induced poling or flexoelectric poling. This was observed by the development of a remanent polarization in flexoelectric measurements, an induced d33 piezoelectric response even after the strain gradient was removed, and the production of an internal bias of 9 kV m-1. It is concluded that residual ferroelectric response considerably enhances the observed flexoelectric response.

Garten, Lauren M.; Trolier-McKinstry, Susan

2015-03-01

280

Piezoelectric and ferroelectric properties of SrBi 2(Nb 1? ? Ta ? ) 2O 9 ceramics  

Microsoft Academic Search

SrBi2(Nb1??Ta?)2O9 (0???1.0) bismuth layered structured ferroelectric (BLSF) ceramics were prepared by the conventional solid-state reaction sintering method. XRD analysis indicated that a single phase of SrBi2(Nb1??Ta?)2O9 was formed for all compositions. The substitution of Ta for Nb decreases Curie temperature (Tc), maximum permittivity (?m), remnant polarization (Pr) and coercive field (Ec), whereas temperature coefficient of resonance frequency (TCF) increases with

Lin Sun; Chude Feng; Lidong Chen; Shiming Huang; Xiaowei Wen

2006-01-01

281

Influence of a silver epoxy dopant on the performance of broken piezoelectric ceramic transducer based on an analytical model  

NASA Astrophysics Data System (ADS)

Over the past decade, an unprecedented increase in the types of, the methods of using, and the demand for piezoelectric ceramic transducers (PCTs) has been observed in the market. These factors increase the probability of PCTs being subjected to breakage. Therefore, this study proposes a simple, low-cost procedure which uses available components to repair and reinstall five broken PCTs and then tests them as emitters and receivers in bulk and surface wave detection. An SM211 PCT with a 7.2 MHz frequency, a high damping and electromechanical coupling coefficient, and two silver electrodes were selected for the experiment. A Mason circuit was used for the procedure, the Laplace transform was used as a mathematical analysis method, and MATLAB was the technical computing language used to model the new transfer function for this type of PCT. This study proved that silver electrodes are a significant load on PCTs, particularly at high frequencies. Very good identity correlations between this mathematical and the experimental responses of the standard PCT were obtained. Later this mathematical model was used to prove the explanations provided by this research. The response of the standard PCT was compared with that of the samples of PCT that have been repaired (SPCTR). Through this comparison, many conclusions were obtained, and several recommendations were made, which can be taken advantage of by people who are interested in this field of research. Such recommendations include analyzing the response of SPCTR and explaining the types of ultrasonic tests in which SPCTR can be used.

Abdulhamed Mohammed, Arshed; Haris, Sallehuddin Mohamed; Zaki Nuawi, Mohd

2014-04-01

282

Assessment of stapes mobility by use of a newly developed piezoelectric ceramic device. A preliminary experiment in dogs.  

PubMed

A piezoelectric device was developed for assessment of stapes mobility during middle ear surgery. The device comprises a pair of ceramic bimorph elements: one for activation of the stapes and the other to pick up the vibration as an electric output, which varies in accordance with the stapes mobility, ie, the inverse of the cochlear input impedance (Zsc). The device is compact and easily manipulated even in the narrow surgical field of the ear. However, the measuring range is restricted to between 1 and 10 kHz. Measurement of Zsc was conducted with this device in 5 ears of 5 dogs. The mean magnitude of Zsc increased with frequency in the range from 1 to 10 kHz: 0.95 megohm at 1 kHz and 8.8 megohms at 10 kHz. After fixation of the stapes with dental cement, the magnitude increased to more than 10 megohms, except at 1 kHz. The results suggest that the device is useful in detecting decreases in stapes mobility in patients with chronic otitis media. PMID:10823476

Gyo, K; Sato, H; Yumoto, E; Yanagihara, N

2000-05-01

283

Measurement of losses in five piezoelectric ceramics between 2 and 50 MHz.  

PubMed

Approximate formulas including losses to predict the electrical impedance of a thin unloaded piezoelectric plate around antiresonant frequencies of the thickness modes have been derived. To do so, a total loss factor is defined that includes both mechanical and electrical losses. Complex electrical impedance measurements on a lead metaniobate and four PZT-type materials between 2 and 50 MHz have been performed. The total loss factors were deduced from both the peak real impedance and from the -6 dB bandwidth of the real impedance peak. Results for fundamental and harmonic thickness modes on thin plates are discussed and the five materials are compared. It is found that for these piezoceramics the total loss factor is well approximated by a linear function of frequency. Finally, a frequency-dependent loss factor is included in the KLM equivalent circuit and it is shown that the theoretical impedance curves obtained with this model are in good agreement with measurements. PMID:18263177

Lethiecq, M; Patat, F; Pourcelot, L; Tran-Huu-Hue, L P

1993-01-01

284

Grain size effects on dielectric properties of barium strontium titanate composite ceramics  

SciTech Connect

Graphical abstract: The tunability (T) and quality factor (Q) were found to be strongly dependent on the grain sizes. With increasing the grain size, the tunability significantly decreased. In contrary, the quality factor (Q) at microwave frequencies increased with increasing grain size. A moderate tunability while maintaining a high Q value is still realizable for composite ceramics when grain sizes were controlled to a suitable region A (from 6.5 to 15.0 ?m). Highlights: ? The tunability (T) and quality factor (Q) were found to be strongly dependent on the grain sizes. ? With increasing the grain size, the tunability significantly decreased, while the quality factor Q at microwave frequencies increased. ? A moderate tunability while maintaining a high Q value is realizable for composites with grain sizes from about 6.5 to 15.0 ?m. - Abstract: Ba{sub 0.4}Sr{sub 0.6}TiO{sub 3}–Mg{sub 2}TiO{sub 4} composite ceramics with different grain sizes were prepared by three sintering methods. The dielectric constant dependences of temperature and frequency showed an increased degree of diffuseness of the Curie peaks as the grain sizes decreased. The tunability (T) and quality factor (Q) were found to be strongly dependent on the grain sizes. The tunability significantly decreased with increasing the grain size. In contrary, the quality factor (Q) at microwave frequencies increased with increasing grain size. A moderate tunability while maintaining a high Q value is still realizable for composite ceramics with grain sizes from about 6.5 to 15.0 ?m.

Zhang, Qiwei [Functional Materials Research Laboratory, Tongji University, 1239 Siping Road, Shanghai 200092 (China); School of Rare Earth, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Zhai, Jiwei, E-mail: apzhai@tongji.edu.cn [Functional Materials Research Laboratory, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Shen, Bo [Functional Materials Research Laboratory, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Zhang, Haijun [College of Materials and Metallurgy, Wuhan University of Science and Technology, No. 947 Heping Road, Wuhan 430081, Hubei Province (China); Yao, Xi [Functional Materials Research Laboratory, Tongji University, 1239 Siping Road, Shanghai 200092 (China)

2013-03-15

285

Correlation between dielectric breakdown strength and interface polarization in barium strontium titanate glass ceramics  

NASA Astrophysics Data System (ADS)

The correlation between the dielectric breakdown performance and interface polarization was studied by the measurements of the dielectric breakdown strength and impedance spectroscopy as a function of sintering temperatures in a BaO-SrO-TiO2-Al2O3-SiO2 glass ceramic system. It was found that dielectric breakdown strength strongly depends on the interface polarization. The sintering temperature dependence of breakdown strength is attributed to the variation in interfacial polarization based on the results of complex impedance analysis.

Huang, Jiajia; Zhang, Yong; Ma, Tao; Li, Hongtao; Zhang, Linwen

2010-01-01

286

Correlation between dielectric breakdown strength and interface polarization in barium strontium titanate glass ceramics  

SciTech Connect

The correlation between the dielectric breakdown performance and interface polarization was studied by the measurements of the dielectric breakdown strength and impedance spectroscopy as a function of sintering temperatures in a BaO-SrO-TiO{sub 2}-Al{sub 2}O{sub 3}-SiO{sub 2} glass ceramic system. It was found that dielectric breakdown strength strongly depends on the interface polarization. The sintering temperature dependence of breakdown strength is attributed to the variation in interfacial polarization based on the results of complex impedance analysis.

Huang Jiajia; Zhang Yong; Ma Tao [State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Li Hongtao; Zhang Linwen [Institute of Fluid Physics, Chinese Academy of Engineering Physics, Sichuan 621900 (China)

2010-01-25

287

Biocompatible evaluation of barium titanate foamed ceramic structures for orthopedic applications.  

PubMed

The potential of barium titanate (BT) to be electrically active makes it a material of interest in regenerative medicine. To enhance the understanding of this material for orthopedic applications, the in vitro biocompatibility of porous BT fabricated using a direct foaming technique was investigated. Characterization of the resultant foams yielded an overall porosity between 50 and 70% with average pore size in excess of 30 µm in diameter. A mouse osteoblast (7F2) cell line was cultured with the BT to determine the extent of the foams' toxicity using a LDH assay. After 72 h, BT foams showed a comparable cytotoxicity of 6.4?±?0.8% to the 8.4?±?1.5% of porous 45S5 Bioglass®. The in vitro inflammatory response elicited from porous BT was measured as a function of tumor necrosis factor alpha (TNF-?) secreted from a human monocytic leukemia cell line (THP-1). Results indicate that the BT foams do not cause a significant inflammatory response, eliciting a 9.4?±?1.3 pg of TNF-? per mL of media compared with 20.2?±?2.3 pg/mL from untreated cells. These results indicate that porous BT does not exhibit short term cytotoxicity and has potential for orthopedic tissue engineering applications. PMID:23894063

Ball, Jordan P; Mound, Brittnee A; Nino, Juan C; Allen, Josephine B

2014-07-01

288

Polarization switching of and electron emission from lead lanthanum zirconate titanate ceramics  

SciTech Connect

This paper focuses on understanding the influence of material properties on the complicated ferroelectric (FE) emission process. Three different compositions in the lead lanthanum zirconate titanate (PLZT) system were chosen for study, based on their widely different dielectric and ferroelectric properties: antiferroelectric (AFE) 2/95/5, normal ferroelectric 8/65/35, and nonferroelectric 15/65/35. Repeatable emission was obtained from the 2/95/5 composition, which could also be modulated at high frequency (200 kHz). The fast AFE {r_reversible} FE phase transition is responsible for the FE emission properties of this material, which is supported by the relationship between the switching current and the emission current. Comparatively, FE emission from the 8/65/35 composition degraded rapidly, which was attributed to decreases in the remanent polarization. No emission signal was detected from the 15/65/35 composition, because no switching activity occurs, which can be interpreted as additional evidence that electron emission from the previously mentioned two compositions was indeed a FE emission process.

Zhang, W.; Huebner, W. [Univ. of Missouri, Rolla, MO (United States). Dept. of Ceramic Engineering; Sampayan, S.E. [Lawrence Livermore National Lab., CA (United States); Krogh, M.L. [Allied Signal Federal Mfg. and Technologies, Kansas City, MO (United States)

1999-03-01

289

Dielectric and Piezoelectric Properties of Low-Temperature-Sintering Pb(Mg1/2W1/2)O3-Pb(Ni1/3Nb2/3)O3-Pb(Zr,Ti)O3 Ceramics for Multilayer Piezoelectric Actuator  

NASA Astrophysics Data System (ADS)

In this study, in order to develop low-temperature-sintering ceramics for a multilayer piezoelectric actuator, Pb(Mg1/2W1/2)O3-Pb(Ni1/3Nb2/3)O3-Pb(Zr,Ti)O3 (PMW-PNN-PZT) ceramics were fabricated using Li2CO3 and CaCO3 as sintering aids and their dielectric and piezoelectric properties were investigated in relation to the amount of Bi substitution. Piezoelectric actuators require both a high piezoelectric constant (d33) and a high electromechanical coupling factor (kp). Accordingly, in this study, Bi was substituted at the Pb site of basic composition PMW-PNN-PZT ceramics for the enhancement of kp and d33. With increasing Bi substitution, density gradually increased. At the sintering temperature of 900°C, the electromechanical coupling factor (kp) and piezoelectric constant (d33) of PMW-PNN-PZT composition ceramics with 1.0 mol % Bi substitution as well as 0.2 wt % Li2CO3 and 0.25 wt % CaCO3 showed the optimal value of 0.618 and 473 pC/N, respectively, for multilayer piezoelectric actuator application.

Yoo, Juhyun; Yoo, Kyungjin; Lee, Hyunseok; Lee, Sangho; Chung, Kwanghyun; Lee, Hyeunggyu; Kang, Hyungwon

2005-09-01

290

Direct strain energy harvesting in automobile tires using piezoelectric PZT-polymer composites  

NASA Astrophysics Data System (ADS)

Direct piezoelectric strain energy harvesting can be used to power wireless autonomous sensors in environments where low frequency, high strains are present, such as in automobile tires during operation. However, these high strains place stringent demands on the materials with respect to mechanical failure or depolarization, especially at elevated temperatures. In this work, three kinds of ceramic-polymer composite piezoelectric materials were evaluated and compared against state-of-the-art piezoelectric materials. The new composites are unstructured and structured composites containing granular lead zirconate titanate (PZT) particles or PZT fibers in a polyurethane matrix. The composites were used to build energy harvesting patches which were attached to a tire and tested under simulated rolling conditions. The energy density of the piezoelectric ceramic-polymer composite materials is initially not as high as that of the reference materials (a macro-fiber composite and a polyvinylidene fluoride polymer). However, the area normalized power output of the composites after temperature and strain cycling is comparable to that of the reference devices because the piezoelectric ceramic-polymer composites did not degrade during operation.

van den Ende, D. A.; van de Wiel, H. J.; Groen, W. A.; van der Zwaag, S.

2012-01-01

291

Properties of dust particles formed upon sputtering of a barium strontium titanate ceramic target in plasma of high-frequency discharge in oxygen  

NASA Astrophysics Data System (ADS)

We have studied the behavior and properties of dust particles formed upon sputtering of a barium strontium titanate Ba(0.8)Sr(0.2)TiO3 ceramic target in plasma of capacitive high-frequency discharge in oxygen. The particles were accumulated in potential traps situated near the target at a remote position of the substrate. Dependences of the density of accumulated dust on the pressure, discharge power, substrate position, and substrate voltage were determined using laser-radiation scattering. The dimensions and composition of collected dust particles were determined.

Alikhadzhiev, S. Kh.; Lyanguzov, N. V.; Plyaka, P. S.; Tolmachev, G. N.

2014-09-01

292

Residual stress relief due to fatigue in tetragonal lead zirconate titanate ceramics  

SciTech Connect

High energy synchrotron XRD was employed to determine the lattice strain {epsilon}{l_brace}111{r_brace}and diffraction peak intensity ratio R{l_brace}200{r_brace}in tetragonal PZT ceramics, both in the virgin poled state and after a bipolar fatigue experiment. It was shown that the occurrence of microstructural damage during fatigue was accompanied by a reduction in the gradient of the {epsilon}{l_brace}111{r_brace}-cos{sup 2} {psi} plot, indicating a reduction in the level of residual stress due to poling. In contrast, the fraction of oriented 90 Degree-Sign ferroelectric domains, quantified in terms of R{l_brace}200{r_brace}, was not affected significantly by fatigue. The change in residual stress due to fatigue is interpreted in terms of a change in the average elastic stiffness of the polycrystalline matrix due to the presence of inter-granular microcracks.

Hall, D. A.; Mori, T. [School of Materials, University of Manchester, Grosvenor St., Manchester M1 7HS (United Kingdom); Comyn, T. P. [Institute for Materials Research, Woodhouse Lane, University of Leeds, LS2 9JT (United Kingdom); Ringgaard, E. [Meggitt Sensing Systems, Hejreskovvej 18A, 3490 Kvistgaard (Denmark); Wright, J. P. [ESRF, 6 Rue Jules Horowitz, BP-220, 38043 Grenoble Cedex (France)

2013-07-14

293

Polarization Characteristics of High Valence Ion Doped Bismuth Lanthanum Titanate Ceramics  

Microsoft Academic Search

Bi3.25La0.75Ti3?3xNb3xO12 (BLTN) and Bi3.25La0.75Ti3?3xV3xO12 (BLTV) ceramics (x = 0, 0.01, 0.03, 0.05, 0.07 and 0.1) were prepared by a solid state reaction method. For all BLTN and BLTV compositions, bismuth-layered perovskite structures were confirmed using X-ray diffraction. The remanent polarization increases and reaches to the maximum value at x = 0.05 for BLTN and at x = 0.01–0.03 for BLTV

JIN SOO KIM; HAI JOON LEE; SUN HEE KANG; SUN YOUNG LEE; ILL WON KIM

2004-01-01

294

Processing Techniques Developed to Fabricate Lanthanum Titanate Piezoceramic Material for High-Temperature Smart Structures  

NASA Technical Reports Server (NTRS)

Piezoelectric ceramic materials are potential candidates for use as actuators and sensors in intelligent gas turbine engines. For piezoceramics to be applied in gas turbine engines, they will have to be able to function in temperatures ranging from 1000 to 2500 F. However, the maximum use temperature for state-of-the-art piezoceramic materials is on the order of 300 to 400 F. Research activities have been initiated to develop high-temperature piezoceramic materials for gas turbine engine applications. Lanthanum titanate has been shown to have high-temperature piezoelectric properties with Curie temperatures of T(sub c) = 1500 C and use temperatures greater than 1000 C. However, the fabrication of lanthanum titanate poses serious challenges because of the very high sintering temperatures required for densification. Two different techniques have been developed at the NASA Glenn Research Center to fabricate dense lanthanum titanate piezoceramic material. In one approach, lower sintering temperatures were achieved by adding yttrium oxide to commercially available lanthanum titanate powder. Addition of only 0.1 mol% yttrium oxide lowered the sintering temperature by as much as 300 C, to just 1100 C, and dense lanthanum titanate was produced by pressure-assisted sintering. The second approach utilized the same commercially available powders but used an innovative sintering approach called differential sintering, which did not require any additive.

Goldsby, Jon C.; Farmer, Serene C.; Sayir, Ali

2004-01-01

295

Effect of poling temperature on piezoelectricity of CaZrO3-modified (K, Na)NbO3-based lead-free ceramics  

NASA Astrophysics Data System (ADS)

Electrical poling is indispensable for endowing isotropic ferroelectric polycrystals with a net macroscopic polarization and hence piezoelectricity. However, little attention has been paid to the optimization of poling conditions in (K, Na)NbO3-based ceramics with a polymorphic phase transition. This study investigated the electrical properties of CaZrO3-modified (K, Na, Li)(Nb, Ta)O3 lead-free piezoceramics as a function of the poling temperature. Peak piezoelectric coefficient d33 of 352 ± 7 pC/N and planar electromechanical coupling factor kp of 0.47 were obtained at the optimized poling temperature of 120 °C, which crosses the polymorphic phase transition regime. In-depth analysis of the asymmetric polarization hysteresis loops and bipolar strain curves uncovered striking analogy between electrical poling and unipolar cycling in the current system, which is attributed to a competition between domain reorientation and space charge accumulation.

Yao, Fang-Zhou; Wang, Ke; Jo, Wook; Lee, Jae-Shin; Li, Jing-Feng

2014-09-01

296

Remarkably high-temperature stable piezoelectric properties of Bi(Mg0.5Ti0.5)O3 modified BiFeO3-BaTiO3 ceramics  

NASA Astrophysics Data System (ADS)

Dense (1-y)BiFe1-x(Mg0.5Ti0.5)xO3 - yBaTiO3 (BFMT-BT, y = 0.29, x = 0-0.12) ceramics with a pseudocubic perovskite crystal structure exhibit remarkably high-temperature stable piezoelectric properties. In particular, x = 0.03 BFMT-BT ceramics, with a Curie temperature, Tc, of ˜425 °C, show a stable piezoelectric coefficient, d33, of ˜155 pC/N up to a depolarization temperature, Td, of ˜400 °C. This Td is higher than Tc for Pb(Zr,Ti)O3, therefore suggesting BFMT-BT ceramics to be promising high-temperature Pb-free piezoelectric materials.

Zhou, Changrong; Feteira, Antonio; Shan, Xu; Yang, Huabin; Zhou, Qin; Cheng, Jun; Li, Weizhou; Wang, Hua

2012-07-01

297

Phase diagrams, dielectric response, and piezoelectric properties of epitaxial ultrathin (001) lead zirconate titanate films under anisotropic misfit strains  

NASA Astrophysics Data System (ADS)

We develop a nonlinear thermodynamic model to predict the phase stability of ultrathin epitaxial (001)-oriented ferroelectric PbZr1-xTixO3 (PZT) films with x =1.0, 0.9, 0.8, and 0.7 on substrates which induce anisotropic in-plane strains. The theoretical formalism incorporates the relaxation by misfit dislocations at the film deposition temperature, the possibility of formation of ferroelectric polydomain structures, and the effect of the internal electric field that is generated due to incomplete charge screening at the film-electrode interfaces and the termination of the ferroelectric layer. This analysis allows the development of misfit strain phase diagrams that provide the regions of stability of monodomain and polydomain structures at a given temperature, film thickness, and composition. It is shown that the range of stability for rotational monodomain phase is markedly increased in comparison to the same ferroelectric films on isotropic substrates. Furthermore, the model finds a strong similarity between ultrathin PbTiO3 and relatively thicker PZT films in terms of phase stability. The combinations of the in-plane misfit strains that yield a phase transition sequence that results in a polarization rotation from the c-phase (polarization parallel to the [001] direction in the film) to the r-phase, and eventually to an in-plane polarization parallel to the [110] direction (the aa-phase) is determined to be the path with the most attractive dielectric and piezoelectric coefficients resulting in enhancements of 10 to 100 times in the dielectric permittivity and piezoresponse compared to bulk tetragonal ferroelectrics of the same PZT composition.

Qiu, Q. Y.; Alpay, S. P.; Nagarajan, V.

2010-06-01

298

Piezoelectric Properties of Bismuth Layer-Structured Ferroelectric Ceramics with a Preferred Orientation Processed by the Reactive Templated Grain Growth Method  

NASA Astrophysics Data System (ADS)

Dense CaBi4Ti4O15 (CBT) and Na0.475Ca0.05Bi4.475Ti4O15 (NCBT) ceramics with a highly preferred {001} orientation were prepared by the reactive templated grain growth (RTGG) method. Plate-like Bi4Ti3O12 (BIT) particles were synthesized by a molten salt technique and used as the reactive template. The template particles were mixed with other oxide and carbonate powders and aligned by tape-casting. During the sintering, oriented CBT and NCBT were formed in situ topotaxially on the oriented BIT particles, and textured CBT and NCBT ceramics were eventually fabricated by the templated grain growth and densification. The Lotgering {001} orientation degree of the textured ceramics exceeded 90% for secondary-laminate sintered specimens. Textured CBT and NCBT ceramics poled in the perpendicular direction to the preferred <001> axis exhibited electromechanical coupling coefficient (k33) and piezoelectric coefficients (d33 and g33) three times higher than the values for nontextured ceramics with the same composition.

Takeuchi, Tsuguto; Tani, Toshihiko; Saito, Yasuyoshi

1999-09-01

299

Dual-enhancement of ferro-/piezoelectric and photoluminescent performance in Pr{sup 3+} doped (K{sub 0.5}Na{sub 0.5})NbO{sub 3} lead-free ceramics  

SciTech Connect

A mutual enhancement action between the ferro-/piezoelectric polarization and the photoluminescent performance of rare earth Pr{sup 3+} doped (K{sub 0.5}Na{sub 0.5})NbO{sub 3} (KNN) lead-free ceramics is reported. After Pr{sup 3+} doping, the KNN ceramics exhibit the maximum enhancement of ?1.2 times in the ferroelectric remanent polarization strength and ?1.25 times in the piezoelectric coefficient d{sub 33}, respectively. Furthermore, after undergoing a ferro-/piezoelectric polarization treatment, the maximum enhancement of ?1.3 times in photoluminescence (PL) was observed in the poled 0.3% Pr{sup 3+} doped sample. After the trivalent Pr{sup 3+} unequivalently substituting the univalent (K{sub 0.5}Na{sub 0.5}){sup +}, A-sites ionic vacancies will occur to maintain charge neutrality, which may reduce the inner stress and ease the domain wall motions, yielding to the enhancement in ferro-/piezoelectric performance. The polarization-induced enhancement in PL is attributed to the decrease of crystal symmetry abound the Pr{sup 3+} ions after polarization. The dual-enhancement of the ferro-/piezoelectric and photoluminescent performance makes the Pr{sup 3+} doped KNN ceramic hopeful for piezoelectric/luminescent multifunctional devices.

Wei, Yongbin; Jia, Yanmin, E-mail: wuzheng@zjnu.cn, E-mail: ymjia@zjnu.edu.cn; Wu, Jiang; Shen, Yichao [Department of Physics, Zhejiang Normal University, Jinhua 321004 (China); Wu, Zheng, E-mail: wuzheng@zjnu.cn, E-mail: ymjia@zjnu.edu.cn [College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004 (China); Luo, Haosu [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800 (China)

2014-07-28

300

Dual-enhancement of ferro-/piezoelectric and photoluminescent performance in Pr3+ doped (K0.5Na0.5)NbO3 lead-free ceramics  

NASA Astrophysics Data System (ADS)

A mutual enhancement action between the ferro-/piezoelectric polarization and the photoluminescent performance of rare earth Pr3+ doped (K0.5Na0.5)NbO3 (KNN) lead-free ceramics is reported. After Pr3+ doping, the KNN ceramics exhibit the maximum enhancement of ˜1.2 times in the ferroelectric remanent polarization strength and ˜1.25 times in the piezoelectric coefficient d33, respectively. Furthermore, after undergoing a ferro-/piezoelectric polarization treatment, the maximum enhancement of ˜1.3 times in photoluminescence (PL) was observed in the poled 0.3% Pr3+ doped sample. After the trivalent Pr3+ unequivalently substituting the univalent (K0.5Na0.5)+, A-sites ionic vacancies will occur to maintain charge neutrality, which may reduce the inner stress and ease the domain wall motions, yielding to the enhancement in ferro-/piezoelectric performance. The polarization-induced enhancement in PL is attributed to the decrease of crystal symmetry abound the Pr3+ ions after polarization. The dual-enhancement of the ferro-/piezoelectric and photoluminescent performance makes the Pr3+ doped KNN ceramic hopeful for piezoelectric/luminescent multifunctional devices.

Wei, Yongbin; Wu, Zheng; Jia, Yanmin; Wu, Jiang; Shen, Yichao; Luo, Haosu

2014-07-01

301

Piezoelectric thin-film superlattices without using piezoelectric materials N. D. Sharma,1  

E-print Network

magnesium niobate PMN , lead zirconate titanate PZT , and barium strontium titanate BST , even scales, thin-film superlattices yielding apparent piezoelectricity close to 75% of ferroelectric barium titanate may be achievable. © 2010 American Institute of Physics. doi:10.1063/1.3443404 I. INTRODUCTION

302

Enhanced active piezoelectric 0-3 nanocomposites fabricated through electrospun nanowires  

SciTech Connect

The use of monolithic piezoceramic materials in sensing and actuation applications has become quite common over the past decade. However, these materials have several properties that limit their application in practical systems. These materials are very brittle due to the ceramic nature of the monolithic material, making them vulnerable to accidental breakage during handling and bonding procedures. In addition, they have very poor ability to conform to curved surfaces and result in large add-on mass associated with using a typically lead-based ceramic. These limitations have motivated the development of alternative methods of applying the piezoceramic material, including piezoceramic fiber composites and piezoelectric 0-3 composites (also known as piezoelectric paint). Piezoelectric paint is desirable because it can be spayed or painted on and can be used with abnormal surfaces. However, the piezoelectric paint developed in prior studies has resulted in low coupling, limiting its application. In order to increase the coupling of the piezoelectric paint, this effort has investigated the use of piezoelectric nanowires rather than spherical piezoelectric particle, which are difficult to strain when embedded in a polymer matrix. The piezoceramic wires were electrospun from a barium titanate (BaTiO{sub 3}) sol gel to produce fibers with 500-1000 nm diameters and subsequently calcinated to acquire perovskite BaTiO{sub 3}. An active nanocomposite paint was formed using the resulting piezoelectric wires and was compared to the same paint with piezoelectric nanoparticles. The results show that the piezoceramic wires produce 0-3 nanocomposites with as high as 300% increase in electromechanical coupling.

Feenstra, Joel [Department of Mechanical Engineering-Engineering Mechanics, Michigan Technological University, Houghton, Michigan 49931 (United States); Sodano, Henry A. [Department of Mechanical and Aerospace Engineering, Arizona State University, Tempe, Arizona 85287-6106 (United States)

2008-06-15

303

Direct piezoelectric responses of soft composite fiber mats  

NASA Astrophysics Data System (ADS)

Recently soft fiber mats electrospun from solutions of Barium Titanate (BT) ferroelectric ceramics particles and polylactic acid (PLA) were found to have large (d33 ˜ 1 nm/V) converse piezoelectric signals offering a myriad of applications ranging from active implants to smart textiles. Here, we report direct piezoelectric measurements (electric signals due to mechanical stress) of the BT/PLA composite fiber mats at several BT concentrations. A homemade testing apparatus provided AC stresses in the 50 Hz-1.5 kHz-frequency range. The piezoelectric constant d33 ˜ 0.5 nC/N and the compression modulus Y ˜ 104-105 Pa found are in agreement with the prior converse piezoelectric and compressibility measurements. Importantly, the direct piezoelectric signal is large enough to power a small LCD by simple finger tapping of a 0.15 mm thick 2-cm2 area mat. We propose using these mats in active Braille cells and in liquid crystal writing tablets.

Varga, M.; Morvan, J.; Diorio, N.; Buyuktanir, E.; Harden, J.; West, J. L.; Jákli, A.

2013-04-01

304

Dielectric, Ferroelectric, and Piezoelectric Properties of Mn-Doped K0.5Na0.5NbO3 Lead-Free Ceramics  

NASA Astrophysics Data System (ADS)

In this work, study of manganese-doped potassium-sodium niobate ceramics was performed. It was found that, with increasing Mn2+ content from 1 mol.% to 1.5 mol.%, the Q m changed from 60 to near 500 with no appreciable detriment in piezoelectric properties. These properties first increased with 0.5 mol.%, and remained almost constant with 1 mol.% of manganese. Maximum values for d 33, d 31, and k p were 120 pC N-1, 33 pC N-1, and 36%, respectively. Thus, manganese-doped K0.5Na0.5NbO3 ceramics represent an option for high-power applications.

Lopez-Juarez, Rigoberto; Gomez-Vidales, Virginia; Cruz, M. P.; Villafuerte-Castrejon, M. E.

2015-03-01

305

Simple, high-resolution interferometer for the measurement of frequency-dependent complex piezoelectric responses in ferroelectric ceramics  

Microsoft Academic Search

In this paper, we report the development of a simple but precise piezoelectric spectrometer using a Michelson–Morley interferometer. The measurement system has been developed to study the frequency and temperature dependence of the complex piezoelectric and electrostriction coefficients of ferroelectric materials. The spectral data are collected by computer and has significantly wider frequency range and lower noise than other such

Jie-Fang Li; P. Moses; D. Viehland

1995-01-01

306

Ferroelectric instabilities and enhanced piezoelectric response in Ce modified BaTiO3 lead-free ceramics  

NASA Astrophysics Data System (ADS)

The crystal structure, ferroelectric, and piezoelectric behaviors of the Ba(Ti1-xCex)O3 solid solution have been investigated at close composition intervals in the dilute concentration regime. Ce concentration as low as 2 mol. % induces tetragonal-orthorhombic instability and coexistence of the phases, leading to enhanced high-field strain and direct piezoelectric response. Detailed structural analysis revealed tetragonal + orthorhombic phase coexistence for x = 0.02, orthorhombic for 0.03 ? x ? 0.05, and orthorhombic + rhombohedral for 0.06 ? x ? 0.08. The results suggest that Ce-modified BaTiO3 is a potential lead-free piezoelectric material.

Brajesh, Kumar; Kalyani, Ajay Kumar; Ranjan, Rajeev

2015-01-01

307

Dielectric and piezoelectric properties of sodium lithium niobate Na1-xLixNbO3 lead free ferroelectric ceramics  

E-print Network

ferroelectric ceramics G. R. Li & Q. R. Yin & L. Y. Zheng Y. Y. Guo & W. W. Cao Published online: 17 May 2007 curves of LNN ceramics showed that there exist three phase transitions from room temperature up. The solid solution NaxLi1-xNbO3 (LNN) ceramics is a very interest- ing material due to its lead free

Cao, Wenwu

308

Effect of Y-doping on the piezoelectric properties of (1-x)BiScO3-xPbTiO3 high-temperature piezoelectric ceramics  

Microsoft Academic Search

(1-x)Bi(Sc1-yYy)O3-xPbTiO3 (BSYPTx\\/y) ceramics were prepared by the conventional mixed oxide method. It was found that the morphotropic phase boundary (MPB) between rhombohedral and tetragonal phase of BSYPTx\\/y system was moved to the lower PT content with increasing of BiYO3 content. The Curie temperature (TC) near MPB of BSYPTx\\/y ceramics was found to increase with increasing of BiYO3 content. However, the

Qishou Li; Wei Shi; Yuzhi Jiang; Ying Pei; Qiang Chen; Xi Yue; Dingquan Xiao; Jianguo Zhu

2009-01-01

309

Piezoelectric materials used in underwater acoustic transducers  

SciTech Connect

Piezoelectric materials have been used in underwater acoustic transducers for nearly a century. In this paper, we reviewed four different types of piezoelectric materials: piezoelectric ceramics, single crystals, composites, and polymers, which are widely used in underwater acoustic transducers nowadays. Piezoelectric ceramics are the most dominant material type and are used as a single-phase material or one of the end members in composites. Piezoelectric single crystals offer outstanding electromechanical response but are limited by their manufacturing cost. Piezoelectric polymers provide excellent acoustic impedance matching and transducer fabrication flexibility although their piezoelectric properties are not as good as ceramics and single crystals. Composites combined the merits of ceramics and polymers and are receiving increased attention. The typical structure and electromechanical properties of each type of materials are introduced and discussed with respect to underwater acoustic transducer applications. Their advantages and disadvantages are summarized. Some of the critical design considerations when developing underwater acoustic transducers with these materials are also touched upon.

Li, Huidong; Deng, Zhiqun; Carlson, Thomas J.

2012-07-07

310

Light-Intensity-Induced Characterization of Elastic Constants and d33 Piezoelectric Coefficient of PLZT Single Fiber Based Transducers  

PubMed Central

Enhanced functionality of electro-optic devices by implementing piezoelectric micro fibers into their construction is proposed. Lanthanum-modified lead zirconate titanate (PLZT) ceramics are known to exhibit high light transparency, desirable electro-optic properties and fast response. In this study PLZT fibers with a diameter of around 300 microns were produced by a thermoplastic processing method and their light-induced impedance and piezoelectric coefficient were investigated at relatively low light intensity (below 50 mW/cm2). The authors experimentally proved higher performance of light controlled microfiber transducers in comparison to their bulk form. The advantage of the high surface area to volume ratio is shown to be an excellent technique to design high quality light sensors by using fibrous materials. The UV absorption induced change in elastic constants of 3% and 4% for the piezoelectric coefficient d33. PMID:23403643

Kozielski, Lucjan; Erhart, Jiri; Clemens, Frank Jörg

2013-01-01

311

The Effect of Biaxial Texture on the Effective Electromechanical Constants of Pollycrystalline Barium Titanate and Lead Titanate Thin Films  

E-print Network

Barium Titanate and Lead Titanate Thin Films Jennifer L. Ruglovsky1 , Jiangyu Li2 , Kaushik Bhattacharya1 for a polycrystalline film. We explore tetragonal 4MM materials, and give specific results for barium titanate and lead tensor. Increased out-of-plane texturing gives rise to an enhanced piezoelectric effect for barium

Bhattacharya, Kaushik

312

Electric field-induced giant strain and photoluminescence-enhancement effect in rare-Earth modified lead-free piezoelectric ceramics.  

PubMed

In this work, an electric field-induced giant strain response and excellent photoluminescence-enhancement effect was obtained in a rare-earth ion modified lead-free piezoelectric system. Pr(3+)-modified 0.93(Bi0.5Na0.5)TiO3-0.07BaTiO3 ceramics were designed and fabricated by a conventional fabrication process. The ferroelectric, dielectric, piezoelectric, and photoluminescence performances were systematically studied, and a schematic phase diagram was constructed. It was found the Pr(3+) substitution induced a transition from ferroelectric a long-range order structure to a relaxor pseudocubic phase with short-range coherence structure. Around a critical composition of 0.8 mol % Pr(3+), a giant reversible strain of ?0.43% with a normalized strain Smax/Emax of up to 770 pm/V was obtained at ?5 kV/mm. Furthermore, the in situ electric field enhanced the photoluminescence intensity by ?40% in the proposed system. These findings have great potential for actuator and multifunctional device applications, which may also open up a range of new applications. PMID:25664585

Yao, Qirong; Wang, Feifei; Xu, Feng; Leung, Chung Ming; Wang, Tao; Tang, Yanxue; Ye, Xiang; Xie, Yiqun; Sun, Dazhi; Shi, Wangzhou

2015-03-11

313

Improved Piezoelectric Loudspeakers And Transducers  

NASA Technical Reports Server (NTRS)

Loudspeakers and related acoustic transducers of improved type feature both light weight and energy efficiency of piezoelectric transducers and mechanical coupling efficiency. Active component of transducer made from wafer of "rainbow" piezoelectric material, ceramic piezoelectric material chemically reduced on one face. Chemical treatment forms wafer into dishlike shallow section of sphere. Both faces then coated with electrically conductive surface layers serving as electrodes. Applications include high-fidelity loudspeakers, and underwater echo ranging devices.

Regan, Curtis Randall; Jalink, Antony; Hellbaum, Richard F.; Rohrbach, Wayne W.

1995-01-01

314

A Piezoelectric-Piezomagnetic Gyrator  

Microsoft Academic Search

A linear passive unilateral element, which has a high forward\\/backward transmission ratio at all frequencies, is realized by combining two resistances and an electromechanical gyrator according to Gamo's theory. The gyrator consists of three mechanically coupled ceramic elements, two of which may be piezomagnetic and the third piezoelectric, or two of which may be piezoelectric and the third piezomagnetic. In

M. Onoe; M. Sawabe

1962-01-01

315

Optical amplification in disordered electrooptic Tm{sup 3+} and Ho{sup 3+} codoped lanthanum-modified lead zirconate titanate ceramics and study of spectroscopy and communication between cations  

SciTech Connect

Rare earth doped electro-optic (EO) ceramics of lanthanum-modified lead zirconate titanate (PLZT) are promising in building multifunctional optical devices, by taking advantage of both EO effect and optical activity. In this work, the combination of the measured spectra of absorption and photoluminescence, the fluorescent decay, the calculated Judd-Ofelt parameters, and measured single pass gain in Tm{sup 3+}, Ho{sup 3+} codoped PLZT ceramics have marked them out as promising gain media in building electrically controllable lasers/optical amplifiers and other multifunctional devices. Optical energy storage was also observed in the optical amplification dynamics.

Zhao, Hua; Zhang, Kun; Xu, Long; Sun, Fankui; Zhang, Jingwen, E-mail: jingwenz@gmail.com [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Chen, Xuesheng [Department of Physics and Astronomy, Wheaton College, Norton Massachusetts 02766 (United States); Li, Kewen K. [Boston Applied Technologies, Inc., Woburn, Massachusetts 01801 (United States)

2014-02-21

316

Design and modeling of a PZT thin film based piezoelectric micromachined ultrasonic transducer (PMUT)  

E-print Network

The design and modelling framework for a piezoelectric micromachined ultrasonic transducer (PMUT) based on the piezoelectric thin film deposition of lead zirconate titanate (PZT) is defined. Through high frequency vibration ...

Smyth, Katherine Marie

2012-01-01

317

Application of piezoelectric sensors for stress-related measurements in wellbores  

E-print Network

started developing synthetic piezoelectric materials. barium titanate was soon followed by Lead metaniobate and lead zirconate, offering better improvements in both piezoelectric characteristics and physical properties. In 1969, kawai found...

Moras, Vijay Roshan

2000-01-01

318

Microstructure Design of Lead-Free Piezoelectric R. E. Garcia,,  

E-print Network

Microstructure Design of Lead-Free Piezoelectric Ceramics S.-B. Lee, T. S. Key, Z. Liang, R. E-Free Piezoelectrics 2 #12;1 Introduction Recent advances in performance of lead-free piezoelectric ceramics haveC/N [11,12], suggesting further room for improvement. Historically, the effect of microstructure has been

Rohrer, Gregory S.

319

DEVELOPMENT OF HIGH PERFORMANCE BS-PT BASED PIEZOELECTRIC TRANSDUCERS FOR HIGH-TEMPERATURE  

E-print Network

DEVELOPMENT OF HIGH PERFORMANCE BS-PT BASED PIEZOELECTRIC TRANSDUCERS FOR HIGH (BS-PT) based piezoelectric ceramic transducers for high-temperature SHM applications. By controlling environments. KEYWORDS : high-temperatue piezoelectric transducer, microfabrication, polyimide INTRODUCTION

Boyer, Edmond

320

Aging in the relaxor and ferroelectric state of Fe-doped (1-x)(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-xBaTiO{sub 3} piezoelectric ceramics  

SciTech Connect

Aging of piezoelectric properties was investigated in lead-free (1???x)(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-xBaTiO{sub 3} doped with 1at.?% Fe. The relaxor character of the un-poled material prevents macroscopic aging effects, while in the field-induced ferroelectric phase aging phenomena are similar to those found in lead zirconate titanate or barium titanate. Most prominent aging effects are the development of an internal bias field and the decrease of switchable polarization. These effects are temperature activated, and can be explained in the framework of defect complex reorientation. This picture is further supported by electron paramagnetic resonance spectra indicating the existence of (Fe{sub Ti}{sup ?}?V{sub O}{sup ••}){sup •} defect complexes in the Fe-doped material.

Sapper, Eva; Dittmer, Robert; Rödel, Jürgen [Materials Science Department, Technische Universität Darmstadt, 64287 Darmstadt (Germany); Damjanovic, Dragan [Ceramics Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne 1015 (Switzerland); Erdem, Emre [Institute of Physical Chemistry I, Universität Freiburg, 79104 Freiburg (Germany); Keeble, David J. [Division of Electronic Engineering and Physics, University of Dundee, Dundee DD1 4HN (United Kingdom); Jo, Wook [School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Granzow, Torsten [Centre de Recherche Public—Gabriel Lippmann, L-4422 Belvaux (Luxembourg)

2014-09-14

321

Aging in the relaxor and ferroelectric state of Fe-doped (1-x)(Bi1/2Na1/2)TiO3-xBaTiO3 piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

Aging of piezoelectric properties was investigated in lead-free (1 - x)(Bi1/2Na1/2)TiO3-xBaTiO3 doped with 1at. % Fe. The relaxor character of the un-poled material prevents macroscopic aging effects, while in the field-induced ferroelectric phase aging phenomena are similar to those found in lead zirconate titanate or barium titanate. Most prominent aging effects are the development of an internal bias field and the decrease of switchable polarization. These effects are temperature activated, and can be explained in the framework of defect complex reorientation. This picture is further supported by electron paramagnetic resonance spectra indicating the existence of (FeTi'-VO••)• defect complexes in the Fe-doped material.

Sapper, Eva; Dittmer, Robert; Damjanovic, Dragan; Erdem, Emre; Keeble, David J.; Jo, Wook; Granzow, Torsten; Rödel, Jürgen

2014-09-01

322

RMS Titanic  

NSDL National Science Digital Library

RMS Titanic raised a 23- by 14-foot section of the Titanic's outer hull this week. RMS, which has exclusive rights to photograph the Titanic and to possess any items recovered from the wreck, doesn't miss an opportunity to market Titanic-oriented merchandise on their site. Nonetheless, visitors wanting to know more about the Titanic will be interested in the expedition calendar and background information on the Titanic's voyage and the exploration of its remains.

323

Effect of Y and Mn Doping in Pb(T, Zr)O3 Piezoelectric Ceramics on the Resonant Frequency and Capacitance Changes and Aging by Thermal Shock Tests  

NASA Astrophysics Data System (ADS)

The effects of Y and Mn-doping in Pb(Zr, Ti)O3 (PZT) with respect to the resonant frequency changes and the aging phenomena caused by thermal treatment were studied in order to achieve a stable piezoelectric ceramic filter. Good thermal stability as well as a high mechanical quality factor QM were required for the piezoelectric ceramics to fabricate certain types of narrow band monolithic filters. The Cr-doped PZT showed a little aging phenomena in resonant frequency change after thermal shock tests, but QM was not high. The Cr and Mn-doped PZT had a large QM value, but a large amount of resonant frequency change and aging after thermal shock tests. It was observed that the PZT with the addition of Y and Mn has high QM and good temperature stability. These features were suitable for the use in filters and resonators.

Takahashi, Keiichi; Nishida, Masamitsu; Hase, Hiroyuki

1998-09-01

324

Piezoelectric and ferroelectric properties of lead-free LiNbO3-modified 0.97(Bi0.5Na0.5TiO3)-0.03BaZrO3 ceramics  

NASA Astrophysics Data System (ADS)

Lead-free piezoelectric ceramics (1- x) [(0.97Bi0.5Na0.5TiO3)]-0.03BaZrO3- xLiNbO3 (BNT-BZ3- xLN) with x = (0-0.07) were synthesized using the conventional solid-state reaction method, and their crystal structure, microstructure, and dielectric, ferroelectric and piezoelectric properties were investigated as a function of the LN content. The X-ray diffraction patterns revealed the formation of a single-phase perovskite structure for all the LN-modified BNT-BZ ceramics in this study. The results indicate that the LN substitution into BNT-BZ3 induces a transition from a ferroelectric to a diffuse and/or relaxor state accompanying a field-induced strain of 0.20% for x = 0.05 at an applied field of 6 kV/mm. The corresponding dynamic piezoelectric coefficient for this composition was ( S max/ E max = 333 pm/V). A significant reduction of the coercive field ( E c) and enhancement of the piezoelectric constant ( d 33) from 98 pC/N for x = 0 to 117 pC/N x = 0.01 was observed.

Rahman, Jamil Ur; Hussain, Ali; Maqbool, Adnan; Malik, Rizwan Ahmed; Song, Tae Kwon; Kim, Myong Ho; Lee, Soonil; Kim, Won Jeong

2015-02-01

325

Ceramics  

NASA Astrophysics Data System (ADS)

The effects of CuO addition on phase composition, microstructure, sintering behavior, and microwave dielectric properties of 0.80Sm(Mg0.5Ti0.5)O3-0.20 Ca0.8Sr0.2TiO3(8SMT-2CST) ceramics prepared by a conventional solid-state ceramic route have been studied. CuO addition shows no obvious influence on the phase of the 8SMT-2CST ceramics and all the samples exhibit pure perovskite structure. Appropriate CuO addition can effectively promote sintering and grain growth, and consequently improve the dielectric properties of the ceramics. The sintering temperature of the ceramics decreases by 50°C by adding 1.00 wt.%CuO. Superior microwave dielectric properties with a ? r of 29.8, Q × f of 85,500 GHz, and ? f of 2.4 ppm/°C are obtained for 1.00 wt.%CuO doped 8SMT-2CST ceramics sintered at 1500°C, which shows dense and uniform microstructure as well as well-developed grain growth.

Yao, Lichun; Yang, Jian; Qiu, Tai

2014-09-01

326

UHV piezoelectric translator  

SciTech Connect

A UHV compatible piezoelectric translator has been developed to correct for angular misalignments in the crysals of a UHV x-ray monochromator. The unit is small, bakeable to 150/sup 0/C, and uses only ceramic materials for insulation. We report on the construction details, vacuum compatibility, mechanical properties, and uses of the device.

Oversluizen, T.; Watson, G.

1985-01-01

327

Active Piezoelectric Diaphragms  

NASA Technical Reports Server (NTRS)

Several active piezoelectric diaphragms were fabricated by placing unelectroded piezoelectric disks between copper clad films patterned with Inter-Circulating Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is radially distributed electric field that mechanically strains the piezo-ceramic along the Z-axis (perpendicular to the applied electric field), rather than the expected in-plane (XY-axis) direction. Unlike other out of plane piezoelectric actuators, which are benders, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements while maintaining a constant circumference. This paper covers the fabrication and characterization of these diaphragms as a function of poling field strength, ceramic diameter and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage ranging from DC to 10 Hz.

Bryant, Robert G.; Effinger, Robert T., IV; Aranda, Isaiah, Jr.; Copeland, Ben M.; Covington, Ed W., III

2002-01-01

328

Origin of the large piezoelectric activity in (1 -x ) Ba (Z r0.2T i0.8)O3-x (B a0.7C a0.3) Ti O3 ceramics  

NASA Astrophysics Data System (ADS)

The diffusionless pseudobinary phase diagram, monodomain properties, and free energy of (1 -x ) Ba (Z r0.2T i0.8)O3-x (B a0.7C a0.3) Ti O3 are computed for comparison with experimental results. Specifically, the variation of the spontaneous polarization, anisotropy energy, and free energy with respect to temperature, composition, and polarization direction are discussed relative to the results of resonant piezoelectric measurements performed over a wide compositional range as a function of temperature. The phase angle, relative permittivity, piezoelectric and coupling coefficients, and elastic compliances were used to investigate relations between the computed and measured pseudobinary phase diagrams and the measured piezoelectric and elastic properties. It was found that d33 values along the orthorhombic to tetragonal phase boundary are ˜30 % higher than those both along the rhombohedral to orthorhombic phase boundary and in the region where phases converge. It is shown that the reduction in anisotropy energy in these regions of the phase diagram is by itself insufficient to explain the measured properties. The highest small signal piezoelectric activity is found along the orthorhombic to tetragonal phase boundary due to a combination of reduced anisotropy energy, high remanent/spontaneous polarization, and increased elastic softening. The combined computed and experimental results are used to demonstrate that the interdependent behavior of these properties should be considered in the design of engineered piezoelectric ceramics.

Acosta, Matias; Khakpash, Nasser; Someya, Takumi; Novak, Nikola; Jo, Wook; Nagata, Hajime; Rossetti, George A.; Rödel, Jürgen

2015-03-01

329

Piezoelectric hollow sphere transducers: The 'BBs'  

NASA Astrophysics Data System (ADS)

This thesis describes the design, fabrication, modeling and device characteristics of ultrasound transducers developed from millimeter size piezoelectric ceramic hollow spheres. Green ceramic hollow spheres were produced using a coaxial nozzle slurry process and a sacrificial core coating process in the size range of 1-6 mm in diameter and 12-200 ?m in wall thickness. Ceramic powders with the morphotropic phase boundary compositions of lead zirconate titanate solid solution known as PZT-4 and PZT-5A, and a modified lead titanate composition were used in these two processes. After sintering, the desired shapes were obtained by drilling, grinding, or polishing. Sphere surfaces were then coated with an electrode material in desired shapes and area of coverage. Two main poling configurations were studied: a radial poling configuration with inside and outside electrodes, and a tangential poling with top and bottom outside electrodes with several different electrode patterns. Dielectric, piezoelectric and ferroelectric properties of these transducers were measured. Vibration modes were determined using the ATILA™ finite element analysis (FEA) code, and associated resonance frequencies were measured and compared to the calculated values. The effect of sphere dimensions, materials and electrode configurations were analyzed using FEA. It was determined from the finite elements analysis of the structure that wall thickness variations do not have a pronounced affect on the vibrations of the structure at lower frequencies (from kHz to low MHz). Focused transducers were prepared for biomedical ultrasound imaging from dish-shape shell sections of the hollow spheres. Pulse-echo characteristics such as, insertion loss, waveform and bandwidth were measured. These transducers were also modeled using the FEA. Transducer operation frequencies of up to 50 MHz were achieved with f-numbers down to 1. Omnidirectional miniature hydrophones were prepared from radially poled hollow spheres. Underwater sonar performance was evaluated by measuring free field voltage sensitivity (FFVS), transmit voltage response (TVR), source level and directivity beam patterns of these hydrophones. FFVS of -218 dB re 1V/?Pa with a frequency independent response up to 500 kHz, and TVR of 150 dB @1m re 1?Pa/V at 500 kHz were obtained from these transducers. These results were compared to that of the finite element analysis of these devices. Hollow spheres were also placed into multi-element arrays with elements electrically connected to one another in parallel, series or a mix of both. Higher TVR, FFVS and directional beam patterns were obtained from these arrays.

Alkoy, Sedat

330

Low-frequency and resonance magnetoelectric effects in lead zirconate titanate and single-crystal nickel zinc  

E-print Network

magnesium niobate lead titanate (PMN­PT), or barium titanate for the piezoelectric phase.1­8 Layered samplesLow-frequency and resonance magnetoelectric effects in lead zirconate titanate and single in lead zirconate titanate (PZT) and (111) or (110) single-crystal nickel zinc ferrites. Data

Srinivasan, Gopalan

331

Microstructural characteristics and electrical properties of xPb(Mg 1\\/3Ta 2\\/3)O 3–(0.1 ? x)Pb(Mn 1\\/3Sb 2\\/3)O 3–0.9Pb(Zr 0.52Ti 0.48)O 3 high power piezoelectric ceramics  

Microsoft Academic Search

The quaternary piezoelectric ceramics of Pb(Mg1\\/3Ta2\\/3)O3–Pb(Mn1\\/3Sb2\\/3)O3–Pb(Zr0.52Ti0.48)O3 (PMgT–PMnS–PZT) were synthesized with a conventional method. The phase, microstructure, ferroelectric, dielectric and piezoelectric properties were studied in terms of PMgT content. The results indicate that all ceramics have a pure perovskite phase of tetragonal symmetry while the c\\/a ratio increases with PMgT content. The PMgT substitution also promotes the densification of the ceramics

Qian Li; Ying Yang; Dandan Wan; Yu Cheng; Meng Zha

2009-01-01

332

Superior piezoelectric composite films: taking advantage of carbon nanomaterials.  

PubMed

Piezoelectric composites comprising an active phase of ferroelectric ceramic and a polymer matrix have recently found numerous sensory applications. However, it remains a major challenge to further improve their electromechanical response for advanced applications such as precision control and monitoring systems. We here investigated the incorporation of graphene platelets (GnPs) and multi-walled carbon nanotubes (MWNTs), each with various weight fractions, into PZT (lead zirconate titanate)/epoxy composites to produce three-phase nanocomposites. The nanocomposite films show markedly improved piezoelectric coefficients and electromechanical responses (50%) besides an enhancement of ~200% in stiffness. The carbon nanomaterials strengthened the impact of electric field on the PZT particles by appropriately raising the electrical conductivity of the epoxy. GnPs have been proved to be far more promising in improving the poling behavior and dynamic response than MWNTs. The superior dynamic sensitivity of GnP-reinforced composite may be caused by the GnPs' high load transfer efficiency arising from their two-dimensional geometry and good compatibility with the matrix. The reduced acoustic impedance mismatch resulting from the improved thermal conductance may also contribute to the higher sensitivity of GnP-reinforced composite. This research pointed out the potential of employing GnPs to develop highly sensitive piezoelectric composites for sensing applications. PMID:24398819

Saber, Nasser; Araby, Sherif; Meng, Qingshi; Hsu, Hung-Yao; Yan, Cheng; Azari, Sara; Lee, Sang-Heon; Xu, Yanan; Ma, Jun; Yu, Sirong

2014-01-31

333

Superior piezoelectric composite films: taking advantage of carbon nanomaterials  

NASA Astrophysics Data System (ADS)

Piezoelectric composites comprising an active phase of ferroelectric ceramic and a polymer matrix have recently found numerous sensory applications. However, it remains a major challenge to further improve their electromechanical response for advanced applications such as precision control and monitoring systems. We here investigated the incorporation of graphene platelets (GnPs) and multi-walled carbon nanotubes (MWNTs), each with various weight fractions, into PZT (lead zirconate titanate)/epoxy composites to produce three-phase nanocomposites. The nanocomposite films show markedly improved piezoelectric coefficients and electromechanical responses (50%) besides an enhancement of ˜200% in stiffness. The carbon nanomaterials strengthened the impact of electric field on the PZT particles by appropriately raising the electrical conductivity of the epoxy. GnPs have been proved to be far more promising in improving the poling behavior and dynamic response than MWNTs. The superior dynamic sensitivity of GnP-reinforced composite may be caused by the GnPs’ high load transfer efficiency arising from their two-dimensional geometry and good compatibility with the matrix. The reduced acoustic impedance mismatch resulting from the improved thermal conductance may also contribute to the higher sensitivity of GnP-reinforced composite. This research pointed out the potential of employing GnPs to develop highly sensitive piezoelectric composites for sensing applications.

Saber, Nasser; Araby, Sherif; Meng, Qingshi; Hsu, Hung-Yao; Yan, Cheng; Azari, Sara; Lee, Sang-Heon; Xu, Yanan; Ma, Jun; Yu, Sirong

2014-01-01

334

Theoretical and experimental research on the influence of multiple piezoelectric effects on physical parameters of piezoelectric actuator  

NASA Astrophysics Data System (ADS)

Compared with the traditional actuator of machinery and electricity, the piezoelectric actuator has the advantages of a compact structure, small volume, no mechanical friction, athermancy and no electromagnetic interference. Therefore, it has high application value in the fields of MEMS, bioengineering, medical science and so on. This article draws conclusions from the influence of multiple piezoelectric effects on the physical parameters (dielectric coefficient, equivalent capacity, energy conversion and piezoelectric coefficient) of piezoelectric actuators. These data from theoretical and experimental research show the following: (1) The rate between the dielectric coefficient of piezoelectric in mechanical freedom and clamping is obtained from the secondary direct piezoelectric effect, which enhances the dielectric property, increases the dielectric coefficient and decreases the coefficient of dielectric isolation; (2) Under external field, En ( ex ) = E 1 , exterior stress T = 0, that is to say, under the boundary condition of mechanical freedom, piezoelectric can store electric energy and elasticity, which obtains power density, elastic density and an electromechanical coupling factor; (3) According to the piezoelectric strain Si ( 1 ) , piezoelectric displacement Dm ( 2 ) and piezoelectric strain Si ( 3 ) of multiple piezoelectric effects, when the dielectric coefficient of the first converse piezoelectric effect ?33 is 1326 and the dielectric coefficient of the secondary direct piezoelectric effect increases to 3336, the dielectric coefficient of the ceramic chip increases. When the piezoelectric coefficient of the first converse piezoelectric effect d33 is 595 and the piezoelectric coefficient of the secondary direct piezoelectric effect decreases to 240, the piezoelectric coefficient of the ceramic chip will decrease. It is of major significance both in the applications and in basic theory to research the influence of multiple piezoelectric effects on the physical parameters of piezoelectric actuators. On the one hand, this can further increase the control precision of piezoelectric actuators. On the other hand, it can be applied to research on the physical parameters and self-sensing actuators, like piezoelectric quartz and piezoelectric ceramic self-sensing actuators, which will be of great service for MEMS.

Shi, Liping; Zhou, Haimin; Huang, Jie; Tan, Jiliang

2015-04-01

335

Effect of A-site La3+ modified on dielectric and energy storage properties in lead zironate stannate titanate ceramics  

NASA Astrophysics Data System (ADS)

(Pb1-1.5xLax)(Zr0.66Sn0.23Ti0.11)O3 (PLZST) ceramics with different lanthanum (La3+) content (x = 0–6%) were prepared by conventional solid state reaction process, and exhibited excellent electrical properties with high switching field from AFE to FE phase and electric breakdown strength. The maximum dielectric constant (?m) and its corresponding temperature (Tm) decreased with La3+ doping and a phase transition from rhombohedral ferroelectric (FE) to tetragonal antiferroelectric (AFE) state was found at 2% La3+ doping. At room temperature, a maximum energy density of 1.47 J cm?3 was obtained for x = 4%. In addition, electric-field-dependent energy storage properties of PLZST (x = 4%) ceramics have been investigated, which could be ascribed to the AFE–FE phase transition associated with the increase of strain.

Zhuo, Fangping; Li, Qiang; Li, Yuanyuan; Gao, Jinghan; Yan, Qingfeng; Zhang, Yiling; Chu, Xiangcheng; Cao, Wenwu

2014-12-01

336

Effect of annealing treatments on positive temperature coefficient of resistance properties of barium titanate ceramics and a new model for the positive temperature coefficient of resistance effect  

SciTech Connect

Alternating current impedance has shown the presence of three electrical components in a semiconducting barium titanate ceramic that has been processed to give a positive temperature coefficient of resistance (PTCR) effect. Two of the component resistances, R{sub 1} and R{sub 2}, each present a PTCR effect and, from the temperature dependence of their capacitances, they are attributed to different regions, nonferroelectric and ferroelectric, respectively, at the surfaces of individual grains or in the region of inter-grain contacts. The influence of isothermal annealing in air at 1000, 1100, and 1200{degree}C on these PTCR effects was investigated. At the resistance maxima, R{sub max} and T{sub max}, two types of dependence were found for both R{sub 1} and R{sub 2}. At short times, R{sub max} decreased and T{sub max} shifted to higher temperatures; at long times, the reverse occurred and R{sub max} increased while T{sub max} shifted to lower temperature. Capacitance values for both regions were constant at short times but decreased at long times, indicating a thickening of the regions responsible for R{sub 1} and R{sub 2} at long times. The room temperature resistance R{sub 25} was constant at short times but increased dramatically at long times, leading to a decrease in the magnitude of the PTCR effect. A model to account for the observed changes is proposed. Freshly fired ceramics are oxygen deficient and semiconducting; grain surfaces are Ti rich. Oxidative annealing creates an oxidized surface layer and an electron depletion layer just inside the grain surfaces. Counter diffusion through these layers of Ba{sup 2+} and O{sup 2{minus}} ions then occurs so as to partially restore electroneutrality; consequently, the concentration of surface acceptor states, N{sub s}, decreases initially. On prolonged annealing, further oxidation occurs: oxide ions diffuse into the grain cores, with counter diffusion of electrons to the grain surfaces where they are trapped by additional absorbed oxygens leading to an increase in N{sub s}. An explanation is given as to how both ferroelectric and nonferroelectric regions of the ceramics exhibit a PTCR effect. The key parameter that controls the activation barrier to conduction appears to be the polarization of the lattice associated with dipolar fluctuations and ferroelectric domains rather than with the polarizability of the different regions. {copyright} 2001 American Institute of Physics.

Gallego, Marina Martinez; West, Anthony R.

2001-07-01

337

Dielectric properties and relaxor behavior of rare-earth (La, Sm, Eu, Dy, Y) substituted barium zirconium titanate ceramics  

SciTech Connect

Based on the Ti-vacancy defect compensation model (Ba{sub 1-x}Ln{sub x})Zr{sub 0.2}Ti{sub 0.8-x/4}O{sub 3} (Ln=La,Sm,Eu,Dy,Y) ceramics have been fabricated via the conventional solid-state reaction method. The microstructures, dielectric properties, and ferroelectric relaxor behavior of (Ba{sub 1-x}Ln{sub x})Zr{sub 0.2}Ti{sub 0.8-x/4}O{sub 3} ceramics have been investigated. The results indicate that rare-earth ions with various ionic radii enter the unit cell to substitute for A-site Ba{sup 2+} ions and inhibit the grain growth. The typical ferroelectric relaxor behavior is induced due to the rare-earth ions substitution. The diffuseness of the phase transition and the degree of ferroelectric relaxor behavior are enhanced, the T{sub C} is remarkably shifted to lower temperature, and the tunability is suppressed with the increase of x value and substituted ionic radius for (Ba{sub 1-x}Ln{sub x})Zr{sub 0.2}Ti{sub 0.8-x/4}O{sub 3} (x=0.005-0.04, Ln=La,Sm,Eu,Dy,Y) ceramics. Tunable ferroelectric materials with moderate dielectric constant and low dielectric loss can be obtained by manipulating the doping amount of suitable rare-earth ions.

Chou Xiujian; Zhai Jiwei; Jiang Haitao; Yao Xi [Functional Materials Research Laboratory, Tongji University, Siping Road 1239, Shanghai 200092 (China)

2007-10-15

338

Hole conduction and electro-mechanical properties of Na0.5Bi2.5Ta2O9-based piezoelectric ceramics with the Li+/Ce3+/Sc3+ modification  

NASA Astrophysics Data System (ADS)

Na0.5Bi2.5Ta2O9-based piezoelectric ceramics, Na0.5-xBi0.5-xLixCexBi2Ta2-xScxO9-x (NBTO-x, x = 0-0.05), were synthesized by using a solid-state reaction process, and their electro-mechanical properties and electrical conduction behaviors were investigated in detail. The Li+/Ce3+/Sc3+ modification improved the electro-mechanical properties of the ceramics effectively, whereas further N2 or O2 annealing led to no obvious increase in piezoelectric coefficient (d33). The composition x = 0.03 ceramic with high temperature stability had a Curie point (Tc) of 784 °C and a d33 of 25.8 pC/N, and its electromechanical coupling factors, kp and kt, were 11.8% and 20.7%, respectively. Variable-atmosphere (air, O2 and N2) impedance data suggested that the NBTO-x ceramics were mainly p-type materials contributing from the bulk response, and the conducting species were holes (h•). Therefore, lower bulk resistivity (?) and lower activation energy (Ea) were associated with the treatment with higher PO2 (oxygen partial pressure). In addition, the O2 atmosphere had stronger impact on the conductivity of the pure NBTO than those of the acceptor NBTO-x, and the grain and grain boundary contributed to its resistivity together.

Long, Changbai; Fan, Huiqing; Wu, Yun; Li, Yinghong

2014-08-01

339

Enhanced dielectric and piezoelectric properties of xBaZrO3-(12x)BaTiO3 Liang Dong,1,2  

E-print Network

, hysteresis and aging of properties. Barium titanate (BaTiO3) is of interest in the context of capacitors ferroelectrics, such as lead titanate zirconate, are widely used for such applications due to their excellent for piezoelectricity. Pure BaTiO3 has lower piezoelectric sensi- tivity (d33 % 200pC/N) than lead titanate zirconate

Lakes, Roderic

340

Phase coexistence and high electrical properties in (KxNa0.96-xLi0.04)(Nb0.85Ta0.15)O3 piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

(KxNa0.96-xLi0.04)(Nb0.85Ta0.15)O3 lead-free piezoelectric ceramics were produced by conventional solid-state reaction method. The effects of K/Na ratio on the phase transitional behavior, Raman spectrum, microstructure, and dielectric, piezoelectric, and ferroelectric properties of the ceramics have been investigated. The phase structure of the ceramics undergoes a transition from orthorhombic to tetragonal phase with increasing x. A double-degenerate symmetric O-Nb-O stretching vibration v1 and a triply degenerate symmetric O-Nb-O bending vibration v5 are detected as relatively strong scattering in the Raman spectra. The peak shifts of v5 and v1 modes all have a discontinuity with x between 0.42 and 0.46, which may suggest the coexistence of orthorhombic and tetragonal phases in this range. Properly modifying x reduces the sintering temperature, promotes the grain growth behavior, and improves the density of the ceramics. The polymorphic phase transition (at To -t) is shifted to near room temperature by increasing x to 0.44 (K/Na ratio of about 0.85:1), and the coexistence of orthorhombic and tetragonal phases in the ceramics at x =0.44 results in the optimized electrical properties (d33=291 pC/N, kp=0.54, ?r=1167, tan ?=0.018, To -t=35 °C, TC=351 °C, Pr=27.65 ?C/cm2, and Ec=8.63 kV/cm). The results show that the equal K/Na ratio is not an essential condition in obtaining optimized electrical properties in (KxNa0.96-xLi0.04)(Nb0.85Ta0.15)O3 ceramics.

Chang, Yunfei; Yang, Zupei; Ma, Difei; Liu, Zonghuai; Wang, Zenglin

2009-03-01

341

High electrostrictive coefficient Q33 in lead-free Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 piezoelectric ceramics  

NASA Astrophysics Data System (ADS)

In this study, the electrostrictive effect in Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 (BZT-xBCT, x = 0.4, 0.5, and 0.6) ceramics was investigated to gain understanding of their high piezoelectric activity. The electrostrictive coefficient Q33 of the BZT-xBCT ceramics was observed to be around 0.04 m4/C2, twice that reported for Pb(Zr,Ti)O3-based ceramics. The Q33 was found to be quite stable with respect to temperature and composition for the BZT-xBCT ceramics. The addition of Fe3+ dopant to the ceramics greatly decreased their Curie temperature without affecting their Q33, which remained 0.04 m4/C2. Moreover, a high and hysteresis-free electric-field-induced strain was obtained for 2 at. % Fe-doped BZT-0.5BCT ceramics at room temperature, caused by their high Q33 coefficient and lower-than-room-temperature Curie temperature. The small-signal M33 coefficient of 2 at. % Fe-doped BZT-0.5BCT ceramics was found to be 1.5 × 10-16 m2/V2 (0.32 × 10-16 m2/V2 for undoped counterpart). These results indicate that 2 at. % Fe-doped BZT-0.5BCT ceramics have great potential as alternatives for hard Pb(Zr,Ti)O3 ceramics in actuator applications, where reproducible and non-hysteretic deformation responses are required.

Li, Fei; Jin, Li; Guo, Runping

2014-12-01

342

In-situ fabrication of ceramic\\/Metal nanocomposites by reduction reaction in barium titanate–Metal oxide systems  

Microsoft Academic Search

Novel ceramic\\/metal nanocomposites were prepared by in-situ reduction method in BaTiO3\\/NiO, BaTiO3\\/WO3 and BaTiO3\\/MoO3 systems. The fabrication processes and the phase stability of these metal and metal oxides were studied using X-ray diffraction analysis and thermodynamic consideration. For BaTiO3\\/NiO system, NiO was entirely reduced at 500°C for several hours and dense BaTiO3\\/Ni nanocomposites were obtained without additional reaction phases. However,

Hae Jin Hwang; Motohiro Toriyama; Tohru Sekino; Koichi Niihara

1998-01-01

343

Influence of Sintering Conditions on Doped PZT Ceramics for Base-Metal Electrode Multilayer Actuators  

NASA Astrophysics Data System (ADS)

The influence of sintering atmosphere and copper addition on the microstructural and piezoelectric properties of Mn-doped lead zirconate titanate ceramics (PZT) was investigated. This ceramic powder densifies below 1000°C, enabling the use of copper inner electrodes for a multilayer actuator setup. To simulate the influence of oxidized inner electrodes during sintering, different CuO contents (0 and 1 mol.%) were mixed to the precalcined Mn-doped PZT powder. Ceramic discs were sintered at 950°C in air and analogously in N2, or in steam containing N2 (25 vol.% water vapor content). The electrical characterization of the discs showed that the piezoelectric properties are influenced by the CuO addition as well as by the sintering atmospheres. The large signal piezoelectric constant d33* shows an improvement of at least 20% when CuO is added. CuO acts as a sintering aid, and especially when the ceramics are fired in steam-containing N2, anomalous grain growth occurs.

Denneler, Stefan; Schuh, Carsten; Benkert, Katrin; Moos, Ralf

2012-09-01

344

Dielectric and piezoelectric properties of Bi{sub 2}O{sub 3} added (Pb,Ca,Sr)(Ti,Mn,Sb)O{sub 3} ceramics sintered at low temperature  

SciTech Connect

In this study, in order to develop low temperature sintering ceramics for a thickness mode multilayer piezoelectric transformer, (Pb,Ca,Sr)(Ti,Mn,Sb)O{sub 3} ceramics were fabricated using Na{sub 2}CO{sub 3}, Li{sub 2}CO{sub 3}, MnO{sub 2}, and Bi{sub 2}O{sub 3} as sintering aids at 870, 900, and 930 deg. C. Their respective dielectric and piezoelectric properties were investigated according to the amount of Bi{sub 2}O{sub 3} addition. At the sintering temperature of 900 deg. C, the optimum value was shown for the density of 6.94 g/cm{sup 3}, thickness vibration mode electromechanical coupling factor (henceforth, k{sub t}) of 0.497, thickness vibration mode mechanical quality factor (henceforth, Q{sub mt}) of 3162, and dielectric constant (henceforth, {epsilon}{sub r}) of 209 for thickness mode multilayer piezoelectric transformer application.

Kim, Dohyung; Yoo, Juhyun [Department of Electrical Engineering, Semyung University, Jechon, Chungbuk 390-711 (Korea, Republic of); Kim, Insung; Song, Jaesung [Piezoelectric Devices Research Group, KERI, Changwon 641-12 (Korea, Republic of)

2009-03-15

345

High-Temperature Piezoelectrics with Large Piezoelectric Coefficients  

NASA Astrophysics Data System (ADS)

High-temperature piezoelectric materials are of interest for sensors and actuators in various industrial applications in which the devices are exposed to high temperature. A lot of research has been conducted in this area to bring forth a suitable piezoelectric material having a high Curie temperature for suitable usage at a high temperature with good piezoelectric properties. This report is an attempt to review the state of the art in high-temperature piezoelectric materials, covering their issues and concerns at elevated temperatures. Among the non-ferroelectric crystal classes, langasite and oxyborate crystals retain their piezoelectricity up to a very high temperature, but their piezoelectric coefficient is much smaller compared to a standard piezoelectric material such as lead zirconate titanate. A similar trend has also been observed in ferroelectric crystal class which shows poor piezoelectricity but retains it until a high temperature. Recent studies on solid solutions of bismuth-based oxides and lead titanate with the chemical formulae Bi(Me3+) O3-PbTiO3 and Bi(Me1Me2)O3-PbTiO3 (Me3+ represents a trivalent cation and Me1 and Me2 are cations having a combined valency of 3) show a much application potential of these materials due to improved piezoelectric property and high Curie temperature. BiScO3-PbTiO3, Bi(Mg0.5Ti0.5)O3-PbTiO3, (Bi(Ni0.5Ti0.5)O3-PbTiO3 and Bi(Zn0.5T0.5)O3-PbTiO3 are some interesting high-temperature piezoelectrics from the group of Bi(Me3+)O3-PbTiO3 and Bi(Me1Me2) O3-PbTiO3 which shows superior piezoelectric properties at high temperatures. Among the lead-free piezoelectrics, (K0.5Na0.5)NbO3 demands a special interest for further studies due to its plausible good piezoelectric property at elevated temperature.

Shinekumar, K.; Dutta, Soma

2015-02-01

346

Ceramics  

NASA Astrophysics Data System (ADS)

The microstructure and thermoelectric properties of Yb-doped Ca0.9- x Yb x La0.1 MnO3 (0 ? x ? 0.05) ceramics prepared by using the Pechini method derived powders have been investigated. X-ray diffraction analysis has shown that all samples exhibit single phase with orthorhombic perovskite structure. All ceramic samples possess high relative densities, ranging from 97.04% to 98.65%. The Seebeck coefficient is negative, indicating n-type conduction in all samples. The substitution of Yb for Ca leads to a marked decrease in the electrical resistivity, along with a moderate decrease in the absolute value of the Seebeck coefficient. The highest power factor is obtained for the sample with x = 0.05. The electrical conduction in these compounds is due to electrons hopping between Mn3+ and Mn4+, which is enhanced by increasing Yb content.

Zhang, Bo; Chang, Aimin; Zhao, Qing; Ye, Haitao; Wu, Yiquan

2014-11-01

347

Theoretical model to describe dispersive nonlinear properties of lead zirconatetitanate ceramics  

E-print Network

Theoretical model to describe dispersive nonlinear properties of lead zirconate­titanate ceramics K signals measured in lead zirconate­titanate PZT ceramics suggest the introduction of a revised theoretical

348

An Experimental Study on the Effect of Temperature on Piezoelectric Sensors for Impedance-Based Structural Health Monitoring  

PubMed Central

The electromechanical impedance (EMI) technique is considered to be one of the most promising methods for developing structural health monitoring (SHM) systems. This technique is simple to implement and uses small and inexpensive piezoelectric sensors. However, practical problems have hindered its application to real-world structures, and temperature effects have been cited in the literature as critical problems. In this paper, we present an experimental study of the effect of temperature on the electrical impedance of the piezoelectric sensors used in the EMI technique. We used 5H PZT (lead zirconate titanate) ceramic sensors, which are commonly used in the EMI technique. The experimental results showed that the temperature effects were strongly frequency-dependent, which may motivate future research in the SHM field. PMID:24434878

Baptista, Fabricio G.; Budoya, Danilo E.; de Almeida, Vinicius A. D.; Ulson, Jose Alfredo C.

2014-01-01

349

Polyaniline stabilized barium titanate nanoparticles reinforced epoxy nanocomposites with high dielectric  

E-print Network

Polyaniline stabilized barium titanate nanoparticles reinforced epoxy nanocomposites with high*b and Zhanhu Guo*a Epoxy polymer nanocomposites (PNCs) filled with both barium titanate (BaTiO3) (500 and 100 systems.7 Barium titanate (BaTiO3) exhibiting unique ferroelectricity,8 piezoelectricity9 and high

Guo, John Zhanhu

350

Giant energy density in [001]-textured Pb(Mg1/3Nb2/3)O3-PbZrO3-PbTiO3 piezoelectric ceramics  

SciTech Connect

Pb(Zr,Ti)O3 (PZT) based compositions have been challenging to texture or grow in a single crystal form due to the incongruent melting point of ZrO2. Here we demonstrate the method for achieving 90% textured PZT-based ceramics and further show that it can provide highest known energy density in piezoelectric materials through enhancement of piezoelectric charge and voltage coefficients (d and g). Our method provides more than 5 increase in the ratio d(textured)/d(random). A giant magnitude of d g coefficient with value of 59 000 10 15 m2 N 1 (comparable to that of the single crystal counterpart and 359% higher than that of the best commercial compositions) was obtained.

Yan, Yongke [Bio-Inspired Materials and Devices Laboraory (BMDL); Cho, Kyung-Hoon [Bio-Inspired Materials and Devices Laboraory (BMDL); Maurya, Deepam [ORNL; Kumar, Amit [ORNL; Kalinin, Sergei V [ORNL; Khachaturyan, Armen [State University of New Jersey, The; Priya, Shashank [ORNL

2013-01-01

351

Temperature stability of ([Na{sub 0.5}K{sub 0.5}NbO{sub 3}]{sub 0.93}-[LiTaO{sub 3}]{sub 0.07}) lead-free piezoelectric ceramics  

SciTech Connect

A polymorphic phase transition (PPT) is often engineered into lead-free materials to generate high piezoelectric activity at room temperature, limiting their temperature stability. We report [Na{sub 0.5}K{sub 0.5}NbO{sub 3}]{sub 0.93}-[LiTaO{sub 3}]{sub 0.07} tetragonal ceramics with favorable properties over a broad temperature range due to a high Curie temperature at 447 deg. C and PPT at -15 deg. C involving a transition to a monoclinic rather than low temperature orthorhombic phase. Piezoelectric k{sub 31} and d{sub 31} coefficients varied from 0.19 to 0.14 and -53 to -33 pC/N, respectively, over the range of -15 to 300 deg. C. Strain-electric field loops provided strains of {approx}0.2% and a high-field d{sub 33} of 205 pm/V.

Skidmore, Thomas A.; Comyn, Tim P.; Milne, Steven J. [Institute for Materials Research, University of Leeds, Leeds LS2 9JT (United Kingdom)

2009-06-01

352

Improvement of Temperature Dependence of Piezoelectric Elements  

NASA Astrophysics Data System (ADS)

The relationships between the equivalent circuit constants of a piezoelectric element and the piezoelectric d33- and g33-constants were first clarified. The temperature dependence of the composed equivalent circuit constants was then decreased by connecting the piezoelectric element to a temperature-compensating capacitor, either in series or in parallel. Furthermore, new sandwich-like piezoelectric elements consisting of stacked piezoelectric ceramic and dielectric ceramic layers were constructed to decrease the dependence on temperature. The piezoelectric d33-constant of Pb(Zr, Ti)O3 changed by about 15% over the temperature range of 0 to 160° C. The new sandwich-like element, however, exhibited a change of less than 3% over the same temperature range.

Nagata, Kunihiro; Harashima, Eiki

1994-09-01

353

Variation of Piezoelectric properties and mechanisms across the relaxor-like/Ferroelectric continuum in BiFeO3- (K0.5Bi0.5)TiO3-PbTiO3 ceramics.  

PubMed

1- x - y)BiFeO3-x(K0.5Bi0.5)TiO3-yPbTiO3 (BFKBT- PT) piezoelectric ceramics were investigated across the compositional space and contrasted against the xBiFeO3- (1-x)(K0.5Bi0.5)TiO3 (BF-KBT) system, whereby a range of relaxor-like/ferroelectric behavior was observed. Structural and piezoelectric properties were closely related to the PbTiO3 concentration; below a critical concentration, relaxor-like behavior was identified. The mechanisms governing the piezoelectric behavior were investigated with structural, electrical, and imaging techniques. X-ray diffraction established that longrange non-centrosymmetric crystallographic order was evident above a critical PbTiO3 concentration, y > 0.1125. Commensurate with the structural analysis, electric-field-induced strain responses showed electrostrictive behavior in the PbTiO3-reduced compositions, with increased piezoelectric switching in PbTiO3-rich compositions. Positive-up-negative-down (PUND) analysis was used to confirm electric-field-induced polarization measurements, elucidating that the addition of PbTiO3 increased the switchable polarization and ferroelectric ordering. Piezoresponse force microscopy (PFM) of the BF-KBT-PT system exhibited typical domain patterns above a critical PbTiO3 threshold, with no ferroelectric domains observed in the BF-KBT system in the pseudocubic region. Doping of BiFeO3-PbTiO3 has been unsuccessful in the search for hightemperature materials that offer satisfactory piezoelectric properties; however, this system demonstrates that the partial substitution of alternative end-members can be an effective method. The partial substitution of PbTiO3 into BF-KBT enables long-range non-centrosymmetric crystallographic order, resulting in increased polar order and TC, compared with the pseudocubic region. The search for novel high-temperature piezoelectric ceramics can therefore exploit the accommodating nature of the perovskite family, which allows significant variance in chemical and physical characters in the exploration of new solid-solutions. PMID:25585388

Bennett, James; Shrout, Thomas R; Zhang, Shujun; Owston, Heather E; Stevenson, Tim J; Esat, Faye; Bell, Andrew J; Comyn, T P

2015-01-01

354

Sharp low frequency dissipative effects in tetragonal BaTiO3 ceramics Liang Dong,1  

E-print Network

Debye peaks, in contrast to a broad relaxation peak were observed in tetragonal barium titanate ceramic was recently inferred from the behavior of tetragonal barium titanate ceramics1 in a particulate composite inclusions.2 A more recent study3 of well aged barium titanate ceramics below the Curie point discloses

Lakes, Roderic

355

Diffuse transition and piezoelectric properties of Pb[(Zr 1? x Ti x ) 0.74(Mg 1\\/3Nb 2\\/3) 0.20(Zn 1\\/3Nb 2\\/3) 0.06]O 3 Ceramics  

Microsoft Academic Search

In this work, the piezoelectric ceramic system of Pb[(Zr1?xTix)0.74(Mg1\\/3Nb2\\/3)0.20(Zn1\\/3Nb2\\/3)0.06]O3, 0.47?x?0.57, with composition close to the morphotropic phase boundary, was studied. From the results of X-ray diffraction and piezoelectric measurement, ceramics near x=0.51 were found at the morphotropic phase boundary (MPB) between the tetragonal and pseudocubic perovskite. The planar coupling factor (kp=0.72) is high at compositions near the MPB, but the

Chun Huy Wang

2004-01-01

356

Study on Pb(Zr,Ti)O 3–Pb(Zn 1\\/3Nb 2\\/3)O 3–Pb(Sn 1\\/3Nb 2\\/3)O 3–Pb(Mn 1\\/3Sb 2\\/3)O 3 quinary system piezoelectric ceramics  

Microsoft Academic Search

In this paper, Pb(Zr,Ti)O3–Pb(Zn1\\/3Nb2\\/3)O3–Pb(Sn1\\/3Nb2\\/3)O3–Pb(Mn1\\/3Sb2\\/3)O3 (named briefly PZT–PZN–PSN–PMS) quinary system piezoelectric ceramics with various Zr\\/Ti ratio were prepared by traditional method. The properties of this quinary system piezoelectric ceramics were studied and the effect of Sr2+, Ba2+ doping on dielectric constant ?r3T and Curie temperature Tc were investigated. What's more, the dielectric loss tan? and dielectric constant ?r3T under the strong

Lin Sun; Chude Feng; Qingchi Sun; Hua Zhou

2005-01-01

357

Enhanced magnetoelectric effects in composite of piezoelectric ceramics, rare-earth iron alloys, and shape-optimized nanocrystalline alloys.  

PubMed

An enhancement for magnetoelectric (ME) effects is studied in a three-phase ME architecture consisting of two magnetostrictive Terfenol-D (Tb(0.3)Dy(0.7)Fe(1.92)) plates, a piezoelectric PZT (Pb(Zr,Ti)O3) plate, and a pair of shape-optimized FeCuNbSiB nanocrystalline alloys. By modifying the conventional shape of the magnetic flux concentrator, the shape-optimized flux concentrator has an improved effective permeability (?(eff)) due to the shape-induced demagnetizing effect at its end surface. The flux concentrator concentrates and amplifies the external magnetic flux into Terfenol-D plate by means of changing its internal flux concentrating manner. Consequently, more flux lines can be uniformly concentrated into Terfenol-D plates. The effective piezomagnetic coefficients (d(33m)) of Terfenol-D plate and the ME voltage coefficients (?(ME)) can be further improved under a lower magnetic bias field. The dynamic magneto-elastic properties and the effective magnetic induction of Terfenol-D are taken into account to derive the enhanced effective ME voltage coefficients (?(ME,eff)), the consistency of experimental results and theoretical analyses verifies this enhancement. The experimental results demonstrate that the maximum d(33m) in our proposed architecture achieves 22.48?nm/A under a bias of 114 Oe. The maximum ?(ME) in the bias magnetic range 0-900 Oe reaches 84.73 mV/Oe under the low frequency of 1 kHz, and 2.996 V/Oe under the resonance frequency of 102.3 kHz, respectively. It exhibits a 1.43 times larger piezomagnetic coefficient and a 1.87 times higher ME voltage coefficient under a smaller magnetic bias of 82 Oe than those of a conventional Terfenol-D/PZT/Terfenol-D composite. These shape-induced magnetoelectric behaviors provide the possibility of using this ME architecture in ultra-sensitive magnetic sensors. PMID:24689597

Zhang, Jitao; Li, Ping; Wen, Yumei; He, Wei; Yang, Aichao; Lu, Caijiang

2014-03-01

358

Electric switching in bistable ferrite-piezoelectric microwave resonator  

NASA Astrophysics Data System (ADS)

The electric switching in a bistable ferrite-piezoelectric microwave resonator comprising a mechanically coupled yttrium iron garnet (YIG) ferrite film on a lead zirconate titanate (PZT) piezoelectric plate has been studied. The YIG/PZT resonator exhibits switching between stable states with small and large reflectance for a time on the order of a microsecond.

Ustinov, A. B.; Fetisov, Yu. K.; Lebedev, S. V.; Srinivasan, G.

2010-02-01

359

Computer modelling of barium titanate  

Microsoft Academic Search

Barium titanate is an important material for both scientific and industrial applications. Much of the interest centres around its ferroelectric properties, since it is structurally the most simple in this class. In addition rare-earth doped ceramics are found to exhibit a very steep positive temperature coefficient of resistance (PTCR) above the Curie point. The theory of this PTCR effect is

G. V. Lewis; C. R. A. Catlow

1983-01-01

360

Piezoelectric Polymers  

NASA Technical Reports Server (NTRS)

The purpose of this review is to detail the current theoretical understanding of the origin of piezoelectric and ferroelectric phenomena in polymers; to present the state-of-the-art in piezoelectric polymers and emerging material systems that exhibit promising properties; and to discuss key characterization methods, fundamental modeling approaches, and applications of piezoelectric polymers. Piezoelectric polymers have been known to exist for more than forty years, but in recent years they have gained notoriety as a valuable class of smart materials.

Harrison, J. S.; Ounaies, Z.; Bushnell, Dennis M. (Technical Monitor)

2001-01-01

361

Piezoelectric properties and temperature stability of Mn-doped Pb(Mg1/3Nb2/3)-PbZrO3-PbTiO3 textured ceramics  

NASA Astrophysics Data System (ADS)

In this letter, we report the electromechanical properties of textured 0.4Pb(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3 (PMN-PZT) composition which has relatively high rhombohedral to tetragonal (R-T) transition temperature (TR-T of 160 °C) and Curie temperature (TC of 234 °C) and explore the effect of Mn-doping on this composition. It was found that MnO2-doped textured PMN-PZT ceramics with 5 vol. % BaTiO3 template (T-5BT) exhibited inferior temperature stability. The coupling factor (k31) of T-5BT ceramic started to degrade from 75 °C while the random counterpart showed a very stable tendency up to 180 °C. This degradation was associated with the "interface region" formed in the vicinity of BT template. MnO2 doped PMN-PZT ceramics textured with 3 vol. % BT and subsequently poled at 140 °C (T-3BT140) exhibited very stable and high k31 (>0.53) in a wide temperature range from room temperature to 130 °C through reduction in the interface region volume. Further, the T-3BT140 ceramic exhibited excellent hard and soft combinatory piezoelectric properties of d33 = 720 pC/N, k31 = 0.53, Qm = 403, tan ? = 0.3% which are very promising for high power and magnetoelectric applications.

Yan, Yongke; Cho, Kyung-Hoon; Priya, Shashank

2012-03-01

362

Piezoelectric valve  

DOEpatents

A motorized valve has a housing having an inlet and an outlet to be connected to a pipeline, a saddle connected with the housing, a turn plug having a rod, the turn plug cooperating with the saddle, and a drive for turning the valve body and formed as a piezoelectric drive, the piezoelectric drive including a piezoelectric generator of radially directed standing acoustic waves, which is connected with the housing and is connectable with a pulse current source, and a rotor operatively connected with the piezoelectric generator and kinematically connected with the rod of the turn plug so as to turn the turn plug when the rotor is actuated by the piezoelectric generator.

Petrenko, Serhiy Fedorovich

2013-01-15

363

Piezoelectric transformer structural modeling--a review.  

PubMed

A review on piezoelectric transformer structural modeling is presented. The operating principle and the basic behavior of piezoelectric transformers as governed by the linear theory of piezoelectricity are shown by a simple, theoretical analysis on a Rosen transformer based on extensional modes of a nonhomogeneous ceramic rod. Various transformers are classified according to their structural shapes, operating modes, and voltage transforming capability. Theoretical and numerical modeling results from the theory of piezoelectricity are reviewed. More advances modeling on thermal and nonlinear effects also are discussed. The article contains 167 references. PMID:17571814

Yang, Jiashi

2007-06-01

364

Titan Arum  

Microsoft Academic Search

Titan Arum in the H.F. Thut Greenhouse at Eastern Illinois University is producing its first flower. The Titan Arum or Amorphophallus titanum is a flowering plant with the largest unbranched inflorescence in the world. An exhibit providing a brief history of the plant, information on its reproduction, and pictures of other specimens in bloom is located in the south lobby

Stacey Knight-Davis

2007-01-01

365

Effects of barium titanate nanoparticles on proliferation and differentiation of rat mesenchymal stem cells.  

PubMed

Nanomaterials hold great promise in the manipulation and treatments of mesenchymal stem cells, since they allow the modulation of their properties and differentiation. However, systematic studies have to be carried out in order to assess their potential toxicological effects. The present study reports on biocompatibility evaluation of glycol-chitosan coated barium titanate nanoparticles (BTNPs) on rat mesenchymal stem cells (MSCs). BTNPs are a class of ceramic systems which possess interesting features for biological applications thanks to their peculiar dielectric and piezoelectric properties. Viability was evaluated up to 5 days of incubation (concentrations in the range 0-100 ?g/ml) both quantitatively and qualitatively with specific assays. Interactions cells/nanoparticles were further investigated with analysis of the cytoskeleton conformation, with SEM and TEM imaging, and with AFM analysis. Finally, differentiation in adipocytes and osteocytes was achieved in the presence of high doses of BTNPs, thus highlighting the safety of these nanostructures towards mesenchymal stem cells. PMID:23006571

Ciofani, Gianni; Ricotti, Leonardo; Canale, Claudio; D'Alessandro, Delfo; Berrettini, Stefano; Mazzolai, Barbara; Mattoli, Virgilio

2013-02-01

366

Phase transition behavior and high piezoelectric properties in lead-free BaTiO3CaTiO3BaHfO3 ceramics  

E-print Network

ceramics Dali Wang · Zhaohua Jiang · Bin Yang · Shantao Zhang · Mingfu Zhang · Feifei Guo · Wenwu Cao of lead-free (1-x)Ba(Hf0.16Ti0.84)O3­x (Ba0.70Ca0.30)TiO3 (BCHT) ceramics fabricated by the conventional been proposed based on their dielectric behavior. It is found that BHCT ceramics undergo a complicated

Cao, Wenwu

367

Voltage generation of piezoelectric cantilevers by laser heating  

PubMed Central

Converting ambient thermal energy into electricity is of great interest in harvesting energy from the environment. Piezoelectric cantilevers have previously been shown to be an effective biosensor and a tool for elasticity mapping. Here we show that a single piezoelectric (lead-zirconate titanate (PZT)) layer cantilever can be used to convert heat to electricity through pyroelectric effect. Furthermore, piezoelectric-metal (PZT-Ti) bi-layer cantilever showed an enhanced induced voltage over the single PZT layer alone due to the additional piezoelectric effect. This type of device can be a way for converting heat energy into electricity. PMID:23258941

Hsieh, Chun-Yi; Liu, Wei-Hung; Chen, Yang-Fang; Shih, Wan Y.; Gao, Xiaotong; Shih, Wei-Heng

2012-01-01

368

Structure and ferroelectric studies of (Ba{sub 0.85}Ca{sub 0.15})(Ti{sub 0.9}Zr{sub 0.1})O{sub 3} piezoelectric ceramics  

SciTech Connect

Graphical abstract: - Highlights: • (Ba{sub 0.85}Ca{sub 0.15})(Ti{sub 0.9}Zr{sub 0.1})O{sub 3} (BCTZO) ceramic was synthesized by the ceramic method. • In situ XRD and Raman spectra showed the phase transition of BCTZO around 360 K. • The ceramics showed a tunability of 82% at 40 kV cm{sup ?1} electric field. • BCTZO exhibited good quality factor of 111 at microwave frequencies. • Piezoforce microscopy studies indicated the switchability of ferroelectric domains. - Abstract: We have synthesized and studied the structural and ferroelectric properties of lead-free 0.5(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3}–0.5Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3} ceramics in the temperature region of its ferroelectric transition. The synthesized material showed high dielectric constant, low loss and good pyroelectric figure of merit. From the temperature dependent X-ray diffraction measurements, we determined the tricritical point to be in the temperature range of 303–400 K. The dielectric measurements indicate a diffuse ferroelectric phase transition (DPT) around 360 K in agreement with the X-ray measurements. We studied the evolution of Raman spectra with temperature to understand the nature of phase transition in BaTiO{sub 3} (BTO) and the BCTZO. The results indicates that the transition of ferroelectric–paraelectric state is not sharp as in the case of BTO and the polar state persists through the paraelectric state. In general, our study indicates that there are ferroelectric domains of nanometer size beyond the commonly defined transition temperature. The observation of local piezoelectric hysteresis loop indicated the existence of intrinsic ferroelectric property of the ceramic at the nanoscale. The ceramics exhibited electric field tunable dielectric properties with a tunability of 82% at an applied DC field of 40 kV cm{sup ?1}, low dielectric loss of 0.001 and room temperature pyroelectric coefficient of 6 × 10{sup ?8} C cm{sup ?2} K{sup ?1} and the detectivity of 1.9 × 10{sup ?8} C cm{sup ?1} J{sup ?1}; larger than those reported for other BaTiO{sub 3}-based materials. Overall, our results indicate that BCTZO ceramics with coexistence of rhombohedral–tetragonal phases is a promising candidate for lead-free ferroelectric applications.

Venkata Ramana, E., E-mail: venkataramanaesk@rediffmail.com [I3N-Aveiro, Department of Physics, University of Aveiro, Aveiro 3810 193 (Portugal); Mahajan, A. [Department of Materials and Ceramics Engineering, University of Aveiro, Aveiro 3810 193 (Portugal); Graça, M.P.F.; Mendiratta, S.K.; Monteiro, J.M.; Valente, M.A. [I3N-Aveiro, Department of Physics, University of Aveiro, Aveiro 3810 193 (Portugal)

2013-10-15

369

Perovskite ceramic nanoparticles in polymer composites for augmenting bone tissue regeneration.  

PubMed

There is increasing interest in the use of nanoparticles as fillers in polymer matrices to develop biomaterials which mimic the mechanical, chemical and electrical properties of bone tissue for orthopaedic applications. The objective of this study was to prepare poly(?-caprolactone) (PCL) nanocomposites incorporating three different perovskite ceramic nanoparticles, namely, calcium titanate (CT), strontium titanate (ST) and barium titanate (BT). The tensile strength and modulus of the composites increased with the addition of nanoparticles. Scanning electron microscopy indicated that dispersion of the nanoparticles scaled with the density of the ceramics, which in turn played an important role in determining the enhancement in mechanical properties of the composite. Dielectric spectroscopy revealed improved permittivity and reduced losses in the composites when compared to neat PCL. Nanofibrous scaffolds were fabricated via electrospinning. Induction coupled plasma-optical emission spectroscopy indicated the release of small quantities of Ca(+2), Sr(+2), Ba(+2) ions from the scaffolds. Piezo-force microscopy revealed that BT nanoparticles imparted piezoelectric properties to the scaffolds. In vitro studies revealed that all composites support osteoblast proliferation. Expression of osteogenic genes was enhanced on the nanocomposites in the following order: PCL/CT > PCL/ST > PCL/BT > PCL. This study demonstrates that the use of perovskite nanoparticles could be a promising technique to engineer better polymeric scaffolds for bone tissue engineering. PMID:25379989

Bagchi, Amrit; Meka, Sai Rama Krishna; Rao, Badari Narayana; Chatterjee, Kaushik

2014-12-01

370

Perovskite ceramic nanoparticles in polymer composites for augmenting bone tissue regeneration  

NASA Astrophysics Data System (ADS)

There is increasing interest in the use of nanoparticles as fillers in polymer matrices to develop biomaterials which mimic the mechanical, chemical and electrical properties of bone tissue for orthopaedic applications. The objective of this study was to prepare poly(?-caprolactone) (PCL) nanocomposites incorporating three different perovskite ceramic nanoparticles, namely, calcium titanate (CT), strontium titanate (ST) and barium titanate (BT). The tensile strength and modulus of the composites increased with the addition of nanoparticles. Scanning electron microscopy indicated that dispersion of the nanoparticles scaled with the density of the ceramics, which in turn played an important role in determining the enhancement in mechanical properties of the composite. Dielectric spectroscopy revealed improved permittivity and reduced losses in the composites when compared to neat PCL. Nanofibrous scaffolds were fabricated via electrospinning. Induction coupled plasma-optical emission spectroscopy indicated the release of small quantities of Ca+2, Sr+2, Ba+2 ions from the scaffolds. Piezo-force microscopy revealed that BT nanoparticles imparted piezoelectric properties to the scaffolds. In vitro studies revealed that all composites support osteoblast proliferation. Expression of osteogenic genes was enhanced on the nanocomposites in the following order: PCL/CT > PCL/ST > PCL/BT > PCL. This study demonstrates that the use of perovskite nanoparticles could be a promising technique to engineer better polymeric scaffolds for bone tissue engineering.

Bagchi, Amrit; Rama Krishna Meka, Sai; Narayana Rao, Badari; Chatterjee, Kaushik

2014-12-01

371

Piezoelectric spectroscopy  

Microsoft Academic Search

In this paper, we report the development of a piezoelectric spectrometer using a Michelson-Morely interferometer. The measurement system has been developed to study the frequency and temperature dependence of the complex piezoelectric and electrostriction coefficients of ferroelectric materials. The system is controlled by computer and has very significantly wider frequency range and lower noise than previously developed systems. Results are

Jie Fang Li; Paul Moses; Dwight Viehland

1994-01-01

372

Piezoelectricity Demo  

NSDL National Science Digital Library

This lesson plan from the Oregon Museum of Science and Industry explores the history of piezoelectricity, with hands-on examples of how itâ??s used, models of why it happens, and how it is applied in nanotechnology. Pressing on the piezoelectric buzzer in the background causes a current to flow and the neon bulb in the foreground to glow.

373

Piezoelectric films  

NASA Astrophysics Data System (ADS)

The physical properties of piezoelectric materials for use in microelectronics are described with particular emphasis on SAW propagation. Piezoelectric-film (PF) fabrication processes are discussed, with consideration given to sputtering and chemical vapor deposition. The properties (acoustic, optical, and mechanical) of PFs are examined along with their applications (e.g., in BAW and SAW devices).

Shermergor, Timofei Dmitrievich; Strel'Tsova, Natalia Nikolaevna

374

The effect of stress on the dielectric properties of barium strontium titanate thin films  

E-print Network

The effect of stress on the dielectric properties of barium strontium titanate thin films T. M Barium strontium titanate thin films are being developed as capacitors in dynamic random access memories to their large permittivities, barium strontium titan- ate BST bulk ceramics have long been used to make high

Suo, Zhigang

375

Shear piezoelectric coefficients of PZT, LiNbO3 and PMN-PT at cryogenic temperatures  

NASA Astrophysics Data System (ADS)

Piezoelectric transducers are used to detect stress and to generate nanometer scale displacements but their piezoelectric coefficients decrease with temperature, limiting their performance in cryogenic applications. We have developed a capacitive technique and directly measured the temperature dependence of the shear coefficient d15 for ceramic lead zirconium titanate (PZT), 41° X-cut lithium niobate (LiNbO3) and single crystal lead magnesium niobium-lead titanate (PMN-PT). In PZT, d15 decreases nearly linearly with temperature, dropping by factor of about 4 by 1.3 K. LiNbO3 has the smallest room temperature d15, but its value decreased by only 6% at the lowest temperatures. PMN-PT had the largest value of d15 at room temperature (2.9 × 10?9 m/V, about 45 times larger than for LiNbO3) but it decreased rapidly below 75 K; at 1.3 K, d15 was only about 8% of its room temperature value.

Bukhari, Syed; Islam, Md; Haziot, Ariel; Beamish, John

2014-12-01

376

Self-powered wireless sensor system using MEMS piezoelectric micro power generator (PMPG)  

E-print Network

A thin-film lead zirconate titanate, Pb(Zr,Ti)03, MEMS Piezoelectric Micro Power Generator (PMPG) has been integrated with a commercial wireless sensor node (Telos), to demonstrate a self-powered RF temperature sensor ...

Xia, YuXin, M.B.A. Sloan School of Management.

2006-01-01

377

Elastic, piezoelectric, and dielectric properties of Ba(Zr0.2Ti0.8)O3-50(Ba0.7Ca0.3)TiO3 Pb-free ceramic at the morphotropic phase boundary  

NASA Astrophysics Data System (ADS)

There is an urgent demand for high performance Pb-free piezoelectrics to substitute for the current workhorse, the lead zirconate titanate (PZT) family. Recently, a triple point (also tricritical point) type morphotropic phase boundary (MPB) in Pb-free Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 system has been reported that shows equally as excellent piezoelectricity as soft PZT at room temperature (Liu and Ren6). In the present study, we measured a full set of elastic, piezoelectric, and dielectric properties for the MPB composition, Ba(Zr0.2Ti0.8)O3-50(Ba0.7Ca0.3)TiO3 (BZT-50BCT), by using a resonance method. The resonant method gives piezoelectric properties d33 = 546 pC/N, g33 = 15.3 × 10-3 Vm/N, electromechanical coupling factor k33 = 65%, and the elastic constant s33E = 19.7 × 10-12 m2/N, c33E = 11.3 × 1010 N/m2, which are close to the properties of soft PZT (PZT-5A). Furthermore, the piezoelectric coefficients (k33, d33), the ferroelectric properties (coercive field, remnant polarization), and the elastic constants (s33D, s33E, c33D, c33E) were also determined as a function of temperature ranging from -50 to 60°C. Our results show that the properties are optimal around MPB temperature (room temperature) and decrease with deviations from the MPB temperature. Nevertheless, the piezoelectric coefficient d33 can maintain an appreciable level of 93 pC/N even at -50°C. The high piezoelectric properties can be ascribed to the low polarization anisotropy as well as the elastic softening at MPB.

Xue, Dezhen; Zhou, Yumei; Bao, Huixin; Zhou, Chao; Gao, Jinghui; Ren, Xiaobing

2011-03-01

378

Effects of Fe2O3 addition on the piezoelectric and the dielectric properties of 0.99Pb(Zr0.53Ti0.47)O3-0.01Bi(Y1- x Fe x )O3 ceramics for energy-harvesting devices  

NASA Astrophysics Data System (ADS)

The 0.99Pb(Zr0.53Ti0.47)O3-0.01Bi(Y1- x Fe x )O3 [PZT-BYF(x)] (x = 0.0 - 0.6) piezoelectric ceramics have been synthesized by using a modified conventional solid-state method. Initially, the perovskite Pb(Zr0.53Ti0.47)O3 (PZT) and the cubic-phase Bi(Y1- x Fe x )O3 [BYF(x)] were presynthesized and mixed to prepare PZT-BYF(x) ceramic composites. The effects of BYF(x) addition on the phase formation, microstructure, and piezoelectric/dielectric properties were measured as functions of sintering temperature. In addition to these measurements, the piezoelectric voltage constant ( g 33) and the piezoelectric transduction coefficient ( d 33 × g 33) were measured in order to evaluate the essential criteria for an energy-harvesting material. For all the specimens, X-ray diffraction analyses showed a complete solid solution with co-existing tetragonal and rhombohedral perovskite phases. All the ceramics exhibited denser and finer microstructures, which produced a high relative density of ? 98%. Scanning electron microscopy (SEM) observations revealed that BYF(x) addition enhanced the sintering density through the formation of a liquid phase. The doping with BYF(x) in the PZT system was found to be effective for maintaining a high Curie temperature of around 377-390 °C. With increasing content of Fe2O3 in the BYF(x) system, the piezoelectric and the dielectric properties were significantly improved. At a sintering temperature of 1170 °C, the piezoelectric and the dielectric properties of PZT-BYF(x) ceramics showed desirable values; this resulted in a significantly higher transduction coefficient. The compositions of PZTBYF(0.1), PZT-BYF(0.2), and PZT-BYF(0.3) showed a considerably lower ? 33 T value, but higher d 33 and k p values. Therefore, within the concentration limit of x = 0.1 to 0.3 moles of Fe2O3, the g 33 and the d 33 × g 33 values were improved significantly ( g 33 > 53 × 10-3 Vm/N and d 33 × g 33 > 20000 m2/N). The maximum transduction coefficient of 20167 × 10-15 m2/N was obtained from the composition of PZT-BYF(0.3). The high values of g 33 and d 33 × g 33 make these piezoelectric ceramics potential candidates for applications in energy-harvesting devices.

Mahmud, Iqbal; Ur, Soon-Chul; Yoon, Man-Soon

2014-07-01

379

Effect of composition on electrical properties of lead-free Bi{sub 0.5}(Na{sub 0.80}K{sub 0.20}){sub 0.5}TiO{sub 3}-(Ba{sub 0.98}Nd{sub 0.02})TiO{sub 3} piezoelectric ceramics  

SciTech Connect

Lead-free piezoelectric ceramics with the composition of (1-x)Bi{sub 0.5}(Na{sub 0.80}K{sub 0.20}){sub 0.5}TiO{sub 3}-x(Ba{sub 0.98}Nd{sub 0.02})TiO{sub 3} or (1-x) BNKT-xBNdT (with x = 0-0.20 mol fraction) have been synthesized by a conventional mixed-oxide method. The compositional dependence of phase structure and electrical properties of the ceramics were systemically studied. The optimum sintering temperature of all BNKT-BNdT ceramics was found to be 1125 Degree-Sign C. X-ray diffraction pattern suggested that BNdT effectively diffused into BNKT lattice during sintering to form a solid solution with a perovskite structure. Scanning electron micrographs showed a slight reduction of grain size when BNdT was added. It was found that BNKT-0.10BNdT ceramic exhibited optimum electrical properties ({epsilon}{sub r} = 1716, tan{delta} = 0.0701, T{sub c} = 327 Degree-Sign C, and d{sub 33} = 211 pC/N), suggesting that this composition has a potential to be one of a promising lead-free piezoelectric candidate for dielectric and piezoelectric applications.

Jaita, Pharatree [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Watcharapasorn, Anucha; Jiansirisomboon, Sukanda [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

2013-07-14

380

Piezoelectric nanoparticle-polymer composite foams.  

PubMed

Piezoelectric polymer composite foams are synthesized using different sugar-templating strategies. By incorporating sugar grains directly into polydimethylsiloxane mixtures containing barium titanate nanoparticles and carbon nanotubes, followed by removal of the sugar after polymer curing, highly compliant materials with excellent piezoelectric properties can be fabricated. Porosities and elasticity are tuned by simply adjusting the sugar/polymer mass ratio which gave an upper bound on the porosity of 73% and a lower bound on the elastic coefficient of 32 kPa. The electrical performance of the foams showed a direct relationship between porosity and the piezoelectric outputs, giving piezoelectric coefficient values of ?112 pC/N and a power output of ?18 mW/cm3 under a load of 10 N for the highest porosity samples. These novel materials should find exciting use in a variety of applications including energy scavenging platforms, biosensors, and acoustic actuators. PMID:25353687

McCall, William R; Kim, Kanguk; Heath, Cory; La Pierre, Gina; Sirbuly, Donald J

2014-11-26

381

Evaluation of the Long-Term Performance of Titanate Ceramics for Immobilization of Excess Weapons Plutonium: Results from Pressurized Unsaturated Flow and Single Pass Flow-Through Testing  

Microsoft Academic Search

This report summarizes our findings from pressurized unsaturated flow (PUF) and single-pass flow-through (SPFT) experiments to date. Results from the PUF test of a Pu-bearing ceramic with enclosing surrogate high-level waste glass show that the glass reacts rapidly to alteration products. Glass reaction causes variations in the solution pH in contact with the ceramic materials. We also document variable concentrations

BP McGrail; HT Schaef; JP Icenhower; PF Martin; VL Legore

1999-01-01

382

Piezoelectric properties and thermal stability of Ca0.92(Li,Ce)0.04Bi2Nb2- x W x O9 high-temperature ceramics  

NASA Astrophysics Data System (ADS)

Ca0.92(Li,Ce)0.04Bi2Nb2- x W x O9 ( x = 0.01-0.06) high-temperature piezoceramics were prepared by a conventional solid-state sintered method, and effects of W content on their piezoelectric properties were studied. All samples possess a pure Aurivillius-type structure, showing that Li, Ce, and W dopants have well diffused into the CaBi2Nb2O9 lattice to form a solid solution. The doping with W slightly decreases the Curie temperature ( T C) of the ceramics. In addition, the excellent electrical properties (e.g., d 33 ~ 16.1 pC/N, k p ~ 9.58 %, Q m ~ 4,767) and a high Curie temperature (e.g., T c ~ 925 °C) are simultaneously obtained in the ceramics with x = 0.04, together with an enhanced thermal stability of <900 °C. As a result, the investigated material system provides the promising potential applications in ultra-high-temperature environments.

Wang, Yadan; Wu, Jiagang; Peng, Zhihang; Chen, Qiang; Xin, Deqiong; Xiao, Dingquan; Zhu, Jianguo

2015-04-01

383

Dielectric, piezoelectric and damping properties of novel 2-2 piezoelectric composites  

NASA Astrophysics Data System (ADS)

Here, a strip-shaped 2-2 cement/polymer-based piezoelectric composite was designed and fabricated. The dielectric, piezoelectric and electromechanical coupling properties of the composite were investigated as well as the coupling effects between the thickness and lateral modes of the piezoelectric composites. The dielectric and piezoelectric properties of the composites can be greatly influenced by variations of the piezoelectric ceramic volume fraction and the structural dimensions of the composites. Excellent properties have been achieved for ultrasonic transducer applications in civil engineering monitoring fields, such as large piezoelectric voltage constants, high thickness electromechanical coupling coefficients and low acoustic impedance. The damping property of the composites was especially studied. The maximum damping loss factor of the composites is between 0.28–0.32, and the glass transition temperature is between 55°–66 °C.

Dongyu, Xu; Xin, Cheng; Banerjee, Sourav; Lei, Wang; Shifeng, Huang

2015-02-01

384

Study of BNKLBT-1.5 lead-free ceramic/epoxy 1-3 composites  

SciTech Connect

Bismuth sodium titanate based lead-free ceramic fiber with the chemical formula of 0.885(Bi{sub 0.5}Na{sub 0.5})TiO{sub 3}-0.05(Bi{sub 0.5}K{sub 0.5})TiO{sub 3}-0.015(Bi{sub 0.5}Li{sub 0.5}= )TiO{sub 3}-0.05BaTiO{sub 3}, BNKLBT-1.5, has been fabricated by a powder-based extrusion method. The ceramic fibers with 400 {mu}m diameter were well crystallized after being calcined at 800 deg. C and sintered at 1170 deg. C. The piezoelectric and ferroelectric properties of the single fiber were found to be 155 pC/N and {approx}34.5 {mu}C/cm{sup 2}, respectively, which is comparable with that in bulk sample. 1-3 ceramic/polymer composites were fabricated by two routes, including dice and filled method and fiber pick-and-place method. Theoretical models were used to calculate the piezoelectric properties of the composites and compared with experimental results.

Choy, S. H.; Li, W. K.; Li, H. K.; Lam, K. H.; Chan, H. L. W. [Department of Applied Physics and Materials Research Centre, Hong Kong Polytechnic University, Hunghom, Kowloon, Hong Kong (China)

2007-12-01

385

High-pressure hydrogen materials compatibility of piezoelectric films  

NASA Astrophysics Data System (ADS)

Hydrogen is well known for materials compatibility issues, including blistering and embrittlement in metals, which are challenges for its use as the next-generation "green" fuel. Beyond metals, hydrogen also degrades piezoelectric materials used as actuators used in direct injection hydrogen internal combustion engines. We present the materials compatibility studies of piezoelectric films in high-pressure hydrogen environments. Absorption of high-pressure hydrogen and composition changes were studied with an elastic recoil detection analysis and Rutherford back-scattering spectrometry in lead zirconate titanate and barium titanate thin films. Hydrogen surface degradation in the form of blistering and Pb mixing was also observed.

Alvine, K. J.; Shutthanandan, V.; Bennett, W. D.; Bonham, C. C.; Skorski, D.; Pitman, S. G.; Dahl, M. E.; Henager, C. H.

2010-11-01

386

High Pressure Hydrogen Materials Compatibility of Piezoelectric Films  

SciTech Connect

Abstract: Hydrogen is being considered as a next-generation clean burning fuel. However, hydrogen has well known materials issues, including blistering and embrittlement in metals. Piezoelectric materials are used as actuators in hydrogen fuel technology. We present studies of materials compatibility of piezoelectric films in a high pressure hydrogen environment. Absorption of high pressure hydrogen was studied with Elastic Recoil Detection Analysis (ERDA) and Rutherford Back Scattering (RBS) in lead zirconate titanate (PZT) and barium titanate (BTO) thin films. Hydrogen surface degradation in the form of blistering and Pb mixing was also observed.

Alvine, Kyle J.; Shutthanandan, V.; Bennett, Wendy D.; Bonham, Charles C.; Skorski, Daniel C.; Pitman, Stan G.; Dahl, Michael E.; Henager, Charles H.

2010-12-02

387

Characterizing Titan's Upper Atmosphere Using the Titan  

E-print Network

Characterizing Titan's Upper Atmosphere Using the Titan Global Ionosphere-Thermosphere Model Jared the Thermosphere · We model the upper atmosphere from 500 km up to 1500 km. · Use the Titan Global Ionosphere, Titan (and now Jupiter and Saturn). ­ Details in Ridley et al. [2006], Bell et al. [2010a, 2010b

Johnson, Robert E.

388

Large piezoelectricity in Pb-free 0.96(K0.5Na0.5)0.95Li0.05Nb0.93Sb0.07O3-0.04BaZrO3 ceramic: A perspective from microstructure  

NASA Astrophysics Data System (ADS)

We employ transmission electron microscopy to explore the reason for large piezoelectricity (d33?400pC/N) in a Pb-free 0.96(K0.5Na0.5)0.95Li0.05Nb0.93Sb0.07O3 -0.04BaZrO3 ceramic from microstructure. The result shows that the high piezoelectricity corresponds to a miniaturized nanodomain configuration in a domain hierarchy. The nanodomains disappear on heating accompanied by a reduction in d33 value. Further convergent beam electron diffraction study reveals a coexistence of tetragonal and orthorhombic phase, which indicates that large piezoelectricity of KNLNS0.07-BZ may stem from easy polarization rotation due to low polarization anisotropy on the tetragonal-orthorhombic phase boundary.

Gao, Jinghui; Hao, Yanshuang; Ren, Shuai; Kimoto, Takayoshi; Fang, Minxia; Li, Huiying; Wang, Yu; Zhong, Lisheng; Li, Shengtao; Ren, Xiaobing

2015-02-01

389

Multilayer electromechanical composites with controlled piezoelectric coefficient distribution  

E-print Network

. This technique is an extremely versatile method to fabricate displacement actuators to fabricate monolithic ceramic parts with controlled material property gradients. To obtain a quantifiable method to optimize-2875 ABSTRACT We have fabricated multilayer electromechanical composites with controlled piezoelectric

Aksay, Ilhan A.

390

RMS TITANIC  

NSDL National Science Digital Library

You will be exploring the R.M.S Titanic. This includes an individual passenger, the class system on board, the collision and warnings leading up to it, and the construction of the ship. Hi Hillside Third Graders! Welcome to the Titanic... To watch some videos of the Wreck click on this link below. Scroll down and click on the yellow link above the YouTube screen that says watch more videos. Use the left side of the screen to help you find the word "Wreck Videos". Watch three ...

Miss Law

2010-04-20

391

RMS TITANIC  

NSDL National Science Digital Library

You will be exploring the R.M.S Titanic. This includes an individual passenger, the class system on board, the collision and warnings leading up to it, and the construction of the ship. Introduction: You are going to be a passenger on board the RMS Titanic. You boarded the ship and set sail expecting the experience of a lifetime upon the Ship of Dreams, but what will happen next? In this project we will be exploring how the ship was structured, what activities were ...

klooney

2010-04-20

392

RMS Titanic  

NSDL National Science Digital Library

You will be exploring the R.M.S Titanic. This includes an individual passenger, the class system on board, the collision and warnings leading up to it, and the construction of the ship. Introduction: You are going to be a passenger on board the RMS Titanic. You boarded the ship and set sail expecting the experience of a lifetime upon the Ship of Dreams, but what will happen next? In this project we will be exploring how the ship was structured, what activities were ...

Mr.Taylor

2010-04-20

393

The Titanic  

NSDL National Science Digital Library

You will be exploring the R.M.S Titanic. This includes an individual passenger, the class system on board, the collision and warnings leading up to it, and the construction of the ship. Introduction: You are going to be a passenger on board the RMS Titanic. You boarded the ship and set sail expecting the experience of a lifetime upon the Ship of Dreams, but what will happen next? In this project we will be exploring how the ship was structured, what activities were ...

Ms. Van Vooren

2007-12-04

394

Raman and Dielectric Studies on Lead free (K0.5Na0.5) NbO3 Piezoelectric Ceramics  

NASA Astrophysics Data System (ADS)

The present study demonstrates the preparation of (K0.5Na0.5)NbO3 (KNN) ceramics at low temperatures by using mechanochemical synthesis process. The effect of calcination temperature on structure, and dielectric properties of KNN ceramics have been studied systematically. It is found that both the dielectric constant and tan? of KNN ceramics as a function of temperature exhibited two sharp phase transitions indicating orthorhombic to tetragonal (184°C) and ferroelectric tetragonal to paraelectric cubic phases (385°C). It was observed that the ceramics calcined at 700°C and sintered at 1000°C shows the high Curie temperature, high dielectric permittivity and low dielectric loss. Further with increase in calcination temperature, the ferroelectric tetragonal to paraelectric cubic phase shifted to lower temperatures. Raman spectra of KNN ceramics were obtained and the three characteristic Raman peaks in the spectra of KNN are related to the internal vibrations of the NbO6 octahedron. The effect of processing parameters on dielectric properties and phase transitions studied systematically.

Mahesh, P.; Pamu, D.

2015-02-01

395

Radially sandwiched cylindrical piezoelectric transducer  

NASA Astrophysics Data System (ADS)

A new type of radially sandwiched piezoelectric short cylindrical transducer is developed and its radial vibration is studied. The transducer is composed of a solid metal disk, a radially polarized piezoelectric ceramic short tube and a metal tube. The radial vibrations of the solid metal disk, the radially polarized piezoelectric tube and the metal tube are analyzed and their electromechanical equivalent circuits are introduced. Based on the mechanical boundary conditions among the metal disk, the piezoelectric tube and the metal tube, a three-port electromechanical equivalent circuit for the radially sandwiched transducer is obtained and the frequency equation is given. The theoretical relationship of the resonance and anti-resonance frequencies and the effective electromechanical coupling coefficient with the geometrical dimensions is analyzed. The radial vibration of the sandwiched transducer is simulated by using two different numerical methods. It is shown that the analytical resonance and anti-resonance frequencies are in good agreement with the numerically simulated results. The transducer is expected to be used in piezoelectric resonators, actuators and ultrasonic radiators in ultrasonic and underwater sound applications.

Lin, Shuyu; Fu, Zhiqiang; Zhang, Xiaoli; Wang, Yong; Hu, Jing

2013-01-01

396

FABRICATION AND TESTING OF MICROWAVE SINTERED SOL-GEL SPRAY-ON BISMUTH TITANATE-LITHIUM NIOBATE BASED PIEZOELECTRIC COMPOSITE FOR USE AS A HIGH TEMPERATURE (>500 deg. C) ULTRASONIC TRANSDUCER  

SciTech Connect

Bismuth titanate-lithium niobate based ultrasonic transducers have been fabricated using a sol-gel spray-on deposition technique. These transducers were then tested to determine their potential as high temperature ultrasonic transducers. Fabricated transducers were capable of operating to 1000 deg. C in pulse-echo mode; however, the exposure to such extreme temperatures appears to be destructive to the transducers.

Searfass, C. T.; Baba, A.; Tittmann, B. R. [Engineering Nanostructure Characterization Center (United States); Agrawal, D. K. [Microwave Processing and Engineering Center, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802 (United States)

2010-02-22

397

Fabrication and Testing of Microwave Sintered Sol-Gel Spray-On Bismuth Titanate-Lithium Niobate Based Piezoelectric Composite for Use as a High Temperature (>500° c) Ultrasonic Transducer  

NASA Astrophysics Data System (ADS)

Bismuth titanate-lithium niobate based ultrasonic transducers have been fabricated using a sol-gel spray-on deposition technique. These transducers were then tested to determine their potential as high temperature ultrasonic transducers. Fabricated transducers were capable of operating to 1000° C in pulse-echo mode; however, the exposure to such extreme temperatures appears to be destructive to the transducers.

Searfass, C. T.; Baba, A.; Tittmann, B. R.; Agrawal, D. K.

2010-02-01

398

Strain engineered barium strontium titanate for tunable thin film resonators  

SciTech Connect

Piezoelectric properties of epitaxial (001) barium strontium titanate (BST) films are computed as functions of composition, misfit strain, and temperature using a non-linear thermodynamic model. Results show that through adjusting in-plane strains, a highly adaptive rhombohedral ferroelectric phase can be stabilized at room temperature with outstanding piezoelectric response exceeding those of lead based piezoceramics. Furthermore, by adjusting the composition and the in-plane misfit, an electrically tunable piezoelectric response can be obtained in the paraelectric state. These findings indicate that strain engineered BST films can be utilized in the development of electrically tunable and switchable surface and bulk acoustic wave resonators.

Khassaf, H.; Khakpash, N. [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Sun, F. [Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States); Sbrockey, N. M.; Tompa, G. S. [Structured Materials Industries, Inc., Piscataway, New Jersey 08854 (United States); Kalkur, T. S. [Department of Electrical and Computer Engineering, University of Colorado at Colorado Springs, Colorado Springs, Colorado 80918 (United States); Alpay, S. P., E-mail: p.alpay@ims.uconn.edu [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

2014-05-19

399

High temperature, high power piezoelectric composite transducers.  

PubMed

Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, Stewart

2014-01-01

400

High Temperature, High Power Piezoelectric Composite Transducers  

PubMed Central

Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, StewarT.

2014-01-01

401

Design Parameters of a Miniaturized Piezoelectric Underwater Acoustic Transmitter  

SciTech Connect

The Juvenile Salmon Acoustic Telemetry System (JSATS) project supported by the U.S. Army Corps of Engineers, Portland District, has yielded the smallest acoustic fish tag transmitter commercially available to date. In order to study even smaller fish populations and make the transmitter injectable by needles, the JSATS acoustic micro transmitter needs to be further downsized. As part of the transmitter downsizing effort some of the design parameters of the lead zirconate titanate (PZT) ceramic tube transducer in the transmitter were studied, including the type of PZT, the backing material, the necessary drive voltage, the transmitting bandwidth and the length of the transducer. It was found that, to satisfy the 156-dB source level requirement of JSATS, a square wave with a 10-volt amplitude is required to drive 'soft' PZT transducers. PZT-5H demonstrated the best source level performance. For Navy types I and II, 16 volts or 18 volts were needed. Ethylene-propylene-diene monomer (EPDM) closed-cell foam was found to be the backing material providing the highest source level. The effect of tube length on the source level is also demonstrated in this paper, providing quantitative information for downsizing of small piezoelectric transmitters.

Li, Huidong; Deng, Zhiqun; Yuan, Yong; Carlson, Thomas J.

2012-07-02

402

Evaluation of piezoelectric paints as vibration and acoustic emission sensors  

SciTech Connect

Piezoelectric paints were prepared using lead zirconate titanate (PZT) ceramic powder as a pigment and epoxy resin as a binder. The obtained paints were coated on aluminum test specimens, and were cured at room temperature or at 150 C, thus forming the paint films having thicknesses of 25 to 300 {micro}m and a PZT volume fraction of 53%. These films were then poled at room temperature, and were evaluated with regard to the sensitivities as vibration and acoustic emission sensors in the frequency ranges of 0--25 Hz and 0--1.2 MHz, respectively. The paint film sensitivity obtained under a given poling field depends on the film thickness, the cure temperature, and the PZT/epoxy composition in the pigment paste (an intermediary product of the final paint). A good correlation is found between the sensitivity and the electrical conductivity for all the paint films studied, thus indicating that the actual poling field acting on the PZT particles dispersed in epoxy resin is determined by the electrical conductivity of the paint film.

Egusa, Shigenori [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Iwasawa, Naozumi [Kansai Paint Co., Ltd., Hiratsuka, Kanagawa (Japan). New Business Div.

1994-12-31

403

Processing and characterization of piezoelectric 0-3 PZT/LCT/PA composites  

NASA Astrophysics Data System (ADS)

PZT/LCT/PA (lead zirconate titanate Pb(Zr1-xTix)O3/Liquid crystalline thermosets/polyamide) composites of 0-3 connectivity were fabricated by hot-pressing. Commercially available PZT powder was calcined at different temperatures for the optimization of the composite properties. The phase transition during calcination of the powder was studied by x-ray diffraction and the particle size by light scattering and scanning electron microscopy. The relative permittivity ?r, piezoelectric charge constant d33, conductivity ? and elastic modulus E of the composites were found to increase with increasing ceramic volume fraction phiv. The obtained d33 and g33 values of this newly developed PZT/LCT/PA composite with 50 vol% PZT using a low poling voltage of 60 kV cm-1 and poling time of 30 min are 42 pC N-1 and 65 mV m N-1, respectively, which are high values for this volume fraction in comparison with the other 0-3 composites reported. Good agreement was found between the experimental data of relative permittivity and piezoelectric constants with several theoretical models (Jayasundere, Yamada and Lichtenecker) of 0-3 composites. In order to assess the correlation of the experimental data with the theoretical models, the experimental data obtained from PZT/PA composites were also included.

Babu, I.; van den Ende, D. A.; de With, G.

2010-10-01

404

Micromachined piezoelectric microphones with in-plane directivity  

PubMed Central

Micromachined piezoelectric microphones with in-plane directivity are introduced. A beam rotates about center torsional pivots and is attached to piezoelectrically active end-springs. Rotation of the beam in response to sound pressure gradients produces spring deflections, which, in turn, produce an open-circuit voltage at the piezoelectric films. Prototypes are presented that contain a 20-?m-thick silicon beam and end-springs with 900-nm-thick chemical solution deposited lead zirconate titanate atop the surface of the end-springs. Acoustic directivity measurements are presented that confirm device functionality. PMID:23460759

Kuntzman, Michael L.; Gloria Lee, Jia; Hewa-Kasakarage, Nishshanka N.; Kim, Donghwan; Hall, Neal A.

2013-01-01

405

Evaluation of the Long-Term Performance of Titanate Ceramics for Immobilization of Excess Weapons Plutonium: Results from Pressurized Unsaturated Flow and Single Pass Flow-Through Testing  

SciTech Connect

This report summarizes our findings from pressurized unsaturated flow (PUF) and single-pass flow-through (SPFT) experiments to date. Results from the PUF test of a Pu-bearing ceramic with enclosing surrogate high-level waste glass show that the glass reacts rapidly to alteration products. Glass reaction causes variations in the solution pH in contact with the ceramic materials. We also document variable concentrations of Pu in solution, primarily in colloidal form, which appear to be related to secular variations in solution composition. The apparent dissolution rate of the ceramic waste form, based on Ba concentrations in the effluent, is estimated at {le} 10{sup {minus}5} g/(m{sup 2} {center_dot} d). Pu-bearing colloids were recovered in the size range of 0.2 to 2 {micro}m, but it is not clear that such entities would be transported in a system that is not advective-flow dominated. Results from SPFT experiments give information on the corrosion resistance of two surrogate Pu-ceramics (Ce-pyrochlore and Ce-zirconolite) at 90 C over a pH range of 2 to 12. The two ceramics were doped with minor quantities ({approximately}0.1 mass%) of MoO{sub 3}, so that concentrations of Mo in the effluent solution could be used to monitor the reaction behavior of the materials. The data obtained thus far from experiments with durations up to 150 d do not conclusively prove that the solid-aqueous solution systems have reached steady-state conditions. Therefore, the dissolution mechanism cannot be determined. Apparent dissolution rates of the two ceramic materials based on Ce, Gd, and Mo concentrations in the effluent solutions from the SPFT are nearly identical and vary between 1.1 to 8.5 x 10{sup {minus}4} g/(m{sup 2} {center_dot} d). In addition, the data reveal a slightly amphoteric dissolution behavior, with a minimum apparent rate at pH = 7 to 8, over the pH range examined. Results from two related ceramic samples suggest that radiation damage can have a measurable effect on the dissolution of titanium-based ceramics. The rare earth pyrochlores, Gd{sub 2}Ti{sub 2}O{sub 7} and Lu{sub 2}Ti{sub 2}O{sub 7}, are being studied as part of the DOE Environmental Management Science Program, and the results are germane to this study. The corrosion resistances of both heavy-ion bombarded and pristine (non-bombarded) specimens are being examined with the SPFT test. Initial data indicate that the dissolution rate may increase by a factor of 3 times or more when these materials become amorphous from radiation damage.

BP McGrail; HT Schaef; JP Icenhower; PF Martin; RD Orr; VL Legore

1999-09-13

406

Local piezoelectric behavior in PZT-based thin films for ultrasound transducers  

NASA Astrophysics Data System (ADS)

Piezoelectric microelectromechanical systems (MEMS) are currently used in inkjet printers and precision resonators; numerous additional applications are being investigated for sensors, low-voltage actuators, and transducers. This work was aimed at improving piezoelectric MEMS by taking two approaches: 1) identifying factors affecting the piezoelectric response of ferroelectric thin films and 2) demonstrating integration of these films into a high frequency array transducer. It was found that there are several key factors influencing the piezoelectric response of thin films for a given material composition. First, large grain size improves the piezoelectric response. This was demonstrated using chemical solution deposited lead nickel niobate -- lead zirconate titanate (0.3)Pb(Ni 0.33Nb0.67)O3 - (0.7)Pb(Zr0.45Ti 0.55O3), (PNN-PZT) ferroelectric thin films. It was shown that this composition allows greater microstructural control than does PZT. Dielectric permittivities ranging from 1350 to 1520 and a transverse piezoelectric coefficient e31,f as high as -- 9.7 C/m 2 were observed for films of about 0.25 mum in thickness. The permittivity and piezoelectric response as well as extrinsic contributions to the dielectric constant increased by 14 and 12 % respectively for samples with grain sizes ranging from 110 to 270 nm. A second factor influencing the piezoelectric response is film composition with respect to the morphotropic phase boundary (MPB). The composition dependence of the dielectric and piezoelectric nonlinearities was characterized in epitaxially grown (0.3)Pb(Ni0.33Nb0.67)O3-(0.7)Pb(Zr xTi1-xO3) thin films deposited on SrTiO 3 to minimize the influence of large-angle grain boundaries. Tetragonal, MPB and rhombohedral films were prepared by changing the Zr/Ti ratio. The largest dielectric and piezoelectric nonlinearities were observed for the rhombohedral sample; this resulted from a higher domain wall mobility due to a smaller ferroelectric distortion and superior crystal quality. Thirdly, changes in the mechanical boundary conditions experienced by a ferroelectric thin film were found to influence both the properties and the length scale for correlated motion of domain walls. Microfabrication was employed to release the PZT films from the Si substrate. Nonlinear piezoelectric maps, by band excitation piezoforce microscopy, showed formation of clusters of higher nonlinear activities of similar size for clamped PZT films with different microstructures. However PZT films that had been released from the Si substrate showed a distinct increase in the correlation length associated with coupled domain wall motion, suggesting that the local mechanical boundary conditions, more than microstructure or composition govern the domain wall dynamics. Release of both the local and the global stress states in films produced dielectric nonlinearities comparable to those of bulk ceramics. The second research direction was targeted at demonstrating the functionality of a one dimensional transducer array. A diaphragm geometry was used for the transducer arrays in order to benefit from the unimorph-type displacement of the PZT-SiO2 layers. For this purpose, the PZT and remaining films in the stack were patterned using reactive ion etching and partially released from the underlying silicon substrate by XeF2 etching from the top. Admittance measurements on the fabricated structures showed resonance frequencies at ˜40 MHz for a 80 mum diameter-wide diaphragms with a PZT thickness of 1.74 mum. In-water transmit and receive functionalities were demonstrated. A bandwidth on receive of 80 % centered at 40 MHz was determined during pitch-mode tests.

Griggio, Flavio

407

Resonance magnetoelectric effects in layered magnetostrictive-piezoelectric composites  

Microsoft Academic Search

Magnetoelectric interactions in bilayers of magnetostrictive and piezoelectric phases are mediated by mechanical deformation. This work is concerned with the theory and companion data for magnetoelectric (ME) coupling at electromechanical resonance (EMR) in the layered samples. Estimated ME voltage coefficient versus frequency profiles for nickel, cobalt, or lithium ferrite and lead zirconate titanate (PZT) predict a giant ME effect at

M. I. Bichurin; D. A. Filippov; V. M. Petrov; V. M. Laletsin; N. Paddubnaya; G. Srinivasan

2003-01-01

408

Miniature piezoelectric triaxial accelerometer measures cranial accelerations  

NASA Technical Reports Server (NTRS)

Tiny triaxial accelerometer whose sensing elements are piezoelectric ceramic beams measures human cranial accelerations when a subject is exposed to a centrifuge or other simulators of g environments. This device could be considered for application in dental, medical, and automotive safety research.

Deboo, G. J.; Rogallo, V. L.

1966-01-01

409

Pyroelectric response mechanism of barium strontium titanate ceramics in dielectric bolometer mode: The underlying essence of the enhancing effect of direct current bias field  

NASA Astrophysics Data System (ADS)

Pyroelectric response mechanism of Ba0.70Sr0.30TiO3 ceramics under dielectric bolometer (DB) mode was investigated by dielectric and pyroelectric properties measurement. The variations of total, intrinsic, and induced pyroelectric coefficients (ptot, pint, pind) with temperatures and bias fields were analyzed. pint plays the dominant role to ptot through most of the temperature range and pind will be slightly higher than pint above T0. The essence of the enhancing effect of DC bias field on pyroelectric coefficient can be attributed to the high value of pint. This mechanism is useful for the pyroelectric materials (DB mode) applications.

Mao, Chaoliang; Cao, Sheng; Yan, Shiguang; Yao, Chunhua; Cao, Fei; Wang, Genshui; Dong, Xianlin; Hu, Xu; Yang, Chunli

2013-06-01

410

Bulk Crystal Growth of Piezoelectric PMN-PT Crystals Using Gradient Freeze Technique for Improved SHM Sensors  

NASA Technical Reports Server (NTRS)

There has been a growing interest in recent years in lead based perovskite ferroelectric and relaxor ferroelectric solid solutions because of their excellent dielectric, piezoelectric and electrostrictive properties that make them very attractive for various sensing, actuating and structural health monitoring (SHM) applications. We are interested in the development of highly sensitive and efficient PMN-PT sensors based on large single crystals for the structural health monitoring of composite materials that may be used in future spacecrafts. Highly sensitive sensors are needed for detection of defects in these materials because they often tend to fail by distributed and interacting damage modes and much of the damage occurs beneath the top surface of the laminate and not detectable by visual inspection. Research is being carried out for various combinations of solid solutions for PMN-PT piezoelectric materials and bigger size crystals are being sought for improved sensor applications. Single crystals of this material are of interest for sensor applications because of their high piezoelectric coefficient (d33 greater than 1700 pC/N) and electromechanical coefficients (k33 greater than 0.90). For comparison, the commonly used piezoelectric ceramic lead zirconate titanate (PZT) has a d33 of about 600 pC/N and electromechanical coefficients k33 of about 0.75. At the present time, these piezoelectric relaxor crystals are grown by high temperature flux growth method and the size of these crystals are rather small (3x4x5 mm(exp 3). In the present paper, we have attempted to grow bulk single crystals of PMN-PT in a 2 inch diameter platinum crucible and successfully grown a large size crystal of 67%PMN-33%PT using the vertical gradient freeze technique with no flux. Piezoelectric properties of the grown crystals are investigated. PMN-PT plates show excellent piezoelectric properties. Samples were poled under an applied electric field of 5 kV/cm. Dielectric properties at a frequency of 1 kHz are examined. The grown PMN-PT crystals show typical relaxor dielectric properties. Additionally, the thermal properties of the sample are tested. The results are in good agreement with those found in the literature and some are reported for the first time.

Aggarwal, Mohan D.; Kochary, F.; Penn, Benjamin G.; Miller, Jim

2007-01-01

411

Titanic Research Link  

NSDL National Science Digital Library

Welcome Aboard the Titanic Third Graders! Enjoy your trip into the history of a fatal night. Use the following websites to help answer your research questions: Encyclopedia Titanica Construction Construction Begins Iceberg Inside the RMS Titanic RMS Titanic Inc.-The ShipThe CollisionThe Lure and the LoveTitanic FAQs ...

Miss Law

2012-01-17

412

ORNL debuts Titan supercomputer  

E-print Network

SCIENCE ORNL debuts Titan supercomputer ORNL has completed the installation of Titan--by employing a family of processors called graphic processing units first created for computer gaming. Titan and space limitations inherent in the previous generation of high- performance computers. Titan, which

Pennycook, Steve

413

Radial Field Piezoelectric Diaphragms  

NASA Technical Reports Server (NTRS)

A series of active piezoelectric diaphragms were fabricated and patterned with several geometrically defined Inter-Circulating Electrodes "ICE" and Interdigitated Ring Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is a radially distributed electric field that mechanically strains the piezoceramic along the Z-axis (perpendicular to the applied electric field). Unlike other piezoelectric bender actuators, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements (several times that of the equivalent Unimorph) while maintaining a constant circumference. One of the more intriguing aspects is that the radial strain field reverses itself along the radius of the RFD while the tangential strain remains relatively constant. The result is a Z-deflection that has a conical profile. This paper covers the fabrication and characterization of the 5 cm. (2 in.) diaphragms as a function of poling field strength, ceramic thickness, electrode type and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage at low frequencies. The unique features of these RFDs include the ability to be clamped about their perimeter with little or no change in displacement, the environmentally insulated packaging, and a highly repeatable fabrication process that uses commodity materials.

Bryant, R. G.; Effinger, R. T., IV; Copeland, B. M., Jr.

2002-01-01

414

Piezoelectric trace vapor calibrator  

NASA Astrophysics Data System (ADS)

The design and performance of a vapor generator for calibration and testing of trace chemical sensors are described. The device utilizes piezoelectric ink-jet nozzles to dispense and vaporize precisely known amounts of analyte solutions as monodisperse droplets onto a hot ceramic surface, where the generated vapors are mixed with air before exiting the device. Injected droplets are monitored by microscope with strobed illumination, and the reproducibility of droplet volumes is optimized by adjustment of piezoelectric wave form parameters. Complete vaporization of the droplets occurs only across a 10°C window within the transition boiling regime of the solvent, and the minimum and maximum rates of trace analyte that may be injected and evaporated are determined by thermodynamic principles and empirical observations of droplet formation and stability. By varying solution concentrations, droplet injection rates, air flow, and the number of active nozzles, the system is designed to deliver—on demand—continuous vapor concentrations across more than six orders of magnitude (nominally 290fg/lto1.05?g/l). Vapor pulses containing femtogram to microgram quantities of analyte may also be generated. Calibrated ranges of three explosive vapors at ng/l levels were generated by the device and directly measured by ion mobility spectrometry (IMS). These data demonstrate expected linear trends within the limited working range of the IMS detector and also exhibit subtle nonlinear behavior from the IMS measurement process.

Verkouteren, R. Michael; Gillen, Greg; Taylor, David W.

2006-08-01

415

Piezoelectric Properties of Bismuth Layer-Structured Ferroelectric Ceramics with a Preferred Orientation Processed by the Reactive Templated Grain Growth Method  

Microsoft Academic Search

Dense CaBi4Ti4O15 (CBT) and Na0.475Ca0.05Bi4.475Ti4O15 (NCBT) ceramics with a highly preferred {001} orientation were prepared by the reactive templated grain growth (RTGG) method. Plate-like Bi4Ti3O12 (BIT) particles were synthesized by a molten salt technique and used as the reactive template. The template particles were mixed with other oxide and carbonate powders and aligned by tape-casting. During the sintering, oriented CBT

Tsuguto Takeuchi; Toshihiko Tani; Yasuyoshi Saito

1999-01-01

416

Abstract--Piezoelectricity is an ability of some materials to generate an electric potential in response to applied mechanical  

E-print Network

Abstract--Piezoelectricity is an ability of some materials to generate an electric potential, PZT ceramics I. INTRODUCTION Piezoelectricity is an ability to generate an electric potential that demonstrate the direct piezoelectric effect, which is the generation of electricity upon applied mechanical

Ha, Dong S.

417

Titan Recreation-Titan Bowl and Billiards Student Engagement Report  

E-print Network

Titan Recreation-Titan Bowl and Billiards Student Engagement Report FY 2012-2013 Purpose Statement Titan Recreation strives to enhance participant experiences at CSUF through providing quality physical fitness and overall wellness. Titan Recreation also provides opportunities for cooperative

de Lijser, Peter

418

Future Titan Missions  

NASA Astrophysics Data System (ADS)

New discoveries about Titan from the Cassini-Huygens mission have led to a broad range of mission class studies for future missions, ranging from NASA Discovery class to International Flagship class. Three consistent science themes emerge and serve as a framework for discussing the various mission concepts: Goal A: Explore Titan, an Earth-Like System - How does Titan function as a system? How are the similarities and differences with Earth, and other solar system bodies, a result of the interplay of the geology, hydrology, meteorology, and aeronomy present in the Titan system?; Goal B: Examine Titan’s Organic Inventory—A Path to Prebiological Molecules - What is the complexity of Titan’s organic chemistry in the atmosphere, within its lakes, on its surface, and in its putative subsurface water ocean and how does this inventory differ from known abiotic organic material in meteorites and therefore contribute to our understanding of the origin of life in the Solar System?; and Goal C: Explore Enceladus and Saturn’s magnetosphere—clues to Titan’s origin and evolution - What is the exchange of energy and material with the Saturn magnetosphere and solar wind? What is the source of geysers on Enceladus? Does complex chemistry occur in the geyser source? Within this scientific framework the presentation will overview the Titan Explorer, Titan AND Enceladus Mission, Titan Saturn System Mission, Titan Mare Explorer, and Titan Submersible. Future timelines and plans will be discussed.

Waite, J. H.; Coustenis, A.; Lorenz, R.; Lunine, J.; Stofan, E.

2012-04-01

419

Effect on the grain size of single-mode microwave sintered NiCuZn ferrite and zinc titanate dielectric resonator ceramics.  

PubMed

Microwave sintering of materials significantly depends on dielectric, magnetic and conductive Losses. Samples with high dielectric and magnetic loss such as ferrites could be sintered easily. But low dielectric loss material such as dielectric resonators (paraelectrics) finds difficulty in generation of heat during microwave interaction. Microwave sintering of materials of these two classes helps in understanding the variation in dielectric and magnetic characteristics with respect to the change in grain size. High-energy ball milled Ni0.6Cu0.2Zn0.2Fe1.98O4-delta and ZnTiO3 are sintered in conventional and microwave methods and characterized for respective dielectric and magnetic characteristics. The grain size variation with higher copper content is also observed with conventional and microwave sintering. The grain size in microwave sintered Ni0.6Cu0.2Zn0.2Fe1.98O4-delta is found to be much small and uniform in comparison with conventional sintered sample. However, the grain size of microwave sintered sample is almost equal to that of conventional sintered sample of Ni0.3Cu0.5Zn0.2Fe1.98O4-delta. In contrast to these high dielectric and magnetic loss ferrites, the paraelectric materials are observed to sinter in presence of microwaves. Although microwave sintered zinc titanate sample showed finer and uniform grains with respect to conventional samples, the dielectric characteristics of microwave sintered sample are found to be less than that of conventional sample. Low dielectric constant is attributed to the low density. Smaller grain size is found to be responsible for low quality factor and the presence of small percentage of TiO2 is observed to achieve the temperature stable resonant frequency. PMID:24427876

Sirugudu, Roopas Kiran; Vemuri, Rama Krishna Murthy; Venkatachalam, Subramanian; Gopalakrishnan, Anisha; Budaraju, Srinivasa Murty

2011-01-01

420

Dielectrophoretically structured piezoelectric composites with high aspect ratio piezoelectric particles inclusions  

NASA Astrophysics Data System (ADS)

Piezoelectric composites were prepared by dielectrophoretic alignment of high aspect ratio piezoelectric particles in a thermosetting polymer matrix. A high level of alignment was achieved in the cured composite from a resin containing randomly oriented high aspect ratio particles. Upon application of an electric field during curing of the resin, the particles were found to rotate with their long axes in the direction of the electric field, before coalescing to form chains. The dielectric and piezoelectric properties of the structured composites are well described by an analytical model for composites containing particles arranged into chains. The influence of degree of rotation and aspect ratio of the individual particles as well as their spacing is described with this model. The results correlate with the experimental values for both permittivity and piezoelectric constants in the poling direction. Dielectric and piezoelectric properties were significantly improved with respect to randomly dispersed piezoelectric ceramic powder-polymer composites and the maximum g33 was shifted to a lower volume fraction. The results could have implications for development of dielectric and piezoelectric (nano-)fiber composites for dielectrics such as embedded capcitors, as well as piezoelectrics for sensing and energy harvesting applications.

van den Ende, D. A.; van Kempen, S. E.; Wu, X.; Groen, W. A.; Randall, C. A.; van der Zwaag, S.

2012-06-01

421

Pyroelectric response mechanism of barium strontium titanate ceramics in dielectric bolometer mode: The underlying essence of the enhancing effect of direct current bias field  

SciTech Connect

Pyroelectric response mechanism of Ba{sub 0.70}Sr{sub 0.30}TiO{sub 3} ceramics under dielectric bolometer (DB) mode was investigated by dielectric and pyroelectric properties measurement. The variations of total, intrinsic, and induced pyroelectric coefficients (p{sub tot}, p{sub int}, p{sub ind}) with temperatures and bias fields were analyzed. p{sub int} plays the dominant role to p{sub tot} through most of the temperature range and p{sub ind} will be slightly higher than p{sub int} above T{sub 0}. The essence of the enhancing effect of DC bias field on pyroelectric coefficient can be attributed to the high value of p{sub int}. This mechanism is useful for the pyroelectric materials (DB mode) applications.

Mao, Chaoliang; Cao, Sheng; Yan, Shiguang; Yao, Chunhua; Cao, Fei; Wang, Genshui; Dong, Xianlin [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Changning, Shanghai 200050 (China)] [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Changning, Shanghai 200050 (China); Hu, Xu; Yang, Chunli [Kunming Institute of Physics, Kunming 650223 (China)] [Kunming Institute of Physics, Kunming 650223 (China)

2013-06-17

422

PLZT block data composers operated in differential phase mode. [lanthanum-modified lead zirconate titanate ceramic device for digital holographic memory  

NASA Technical Reports Server (NTRS)

The use of PLZT ceramics with the 7/65/35 composition in block data composer (BDC) input devices for holographic memory systems has previously been described for operation in the strain biased, scattering, and edge effect modes. A new and promising mode of BDC operation is the differential phase mode in which each element of a matrix array BDC acts as a phase modulator. The phase modulation results from a phase difference in the optical path length between the electrically poled and depoled states of the PLZT. It is shown that a PLZT BDC can be used as a matrix-type phase modulator to record and process digital data by the differential phase mode in a holographic recording/processing system with readout contrast ratios of between 10:1 and 15:1. The differential phase mode has the advantages that strain bias is not required and that the thickness and strain variations in the PLZT are cancelled out.

Drake, M. D.; Klingler, D. E.

1973-01-01

423

Virtual Titanic  

NSDL National Science Digital Library

The recent historical and cinematic fascination with the Titanic proves that the allure of this most famous luxury liner remains unsinkable. The Discovery Channel Online has created a captivating site devoted to images, movies (IPIX, QuickTime), and text describing the ship and its demise. While the site contains historical photos and lithographs of the ship as well as underwater photos and movies from a 1985 submersible mission, the unique contribution of this site is its numerous virtual images of the interior and exterior of the Titanic as well as its movies of the collision and sinking. Developed by Andrew Nelson for a CD-ROM game, the movies include a flyby of the ship, a collision movie, a listing movie, and a three-part series of the sinking. Both flat and "bubble" views of such features as the first-class cabins, the wireless room, and the grand staircase are also included. A talk-back section discusses various theories surrounding the sinking and contains several related links.

424

Development of Bismuth-based Lead-free Piezoelectric Materials: Thin Film Piezoelectric Materials via PVD and CSD Routes  

NASA Astrophysics Data System (ADS)

Piezoelectric materials have been widely used in electromechanical actuators, sensors, and ultrasonic transducers. Among these materials, lead zirconate titanate Pb(Zr1-xTix)O3 (PZT) has been primarily investigated due to its excellent piezoelectric properties. However, environmental concerns due to the toxicity of PbO have led to investigations into alternative materials systems. Bismuth-based perovskite piezoelectric materials such as (Bi0.5,Na0.5)TiO3 - (Bi0.5K 0.5)TiO3 (BNT - BKT), (Bi0.5,Na0.5 )TiO3 - (Bi0.5K0.5)TiO3 - BaTiO3(BNT - BKT - BT), (Bi0.5K 0.5)TiO3 - Bi(Zn0.5,Ti0.5)O 3 (BKT - BZT), and (Bi0.5,Na0.5)TiO 3 - (Bi0.5K0.5)TiO3 - Bi(Mg 0.5,Ti0.5)O3 (BNT - BKT - BMgT) have been explored as potential alternatives to PZT. These materials systems have been extensively studied in bulk ceramic form, however many of the ultimate applications will be in thin film embodiments (i.e., microelectromechanical systems). For this reason, in this thesis these lead-free piezoelectrics are synthesized in thin film form to understand the structure-property-processing relationships and their impact on the ultimate device response. Fabrication of high quality of 0.95BKT - 0.05BZT thin films on platinized silicon substrates was attempted by pulsed laser deposition. Due to cation volatility, deposition parameters such as substrate temperature, deposition pressure, and target-substrate distance, as well as target overdoping were explored to achieve phase pure materials. This route led to high dielectric loss, indicative of poor ferroelectric behavior. This was likely a result of the poor thin film morphology observed in films deposited via this method. Subsequently, 0.8BNT - 0.2BKT, 85BNT - 10BKT - 5BT, and 72.5BNT - 22.5BKT - 5BMgT (near morphotropic phase boundary composition) were synthesized via chemical solution deposition. To compensate the loss of A-site cations, overdoped precursor solutions were prepared. Crystallization after each spin cast layer were required to produce phase pure material. Good permittivities and low dielectric loss over the frequency range of 100 Hz to 1 MHz were obtained. Dependent upon annealing conditions, various film morphologies and compositional distributions were observed via electron microscopy and composition measurements. As opposed to previously reported work, good ferroelectric response at low frequency (200 Hz) were found. For BNT - BKT - BMgT, the maximum polarization was over 50 ?C/cm2 with high d33,fof 75 pm/V were obtained. Additionally, the extrinsic and intrinsic contributions to the dielectric response for solution-derived BNT - BKT and BNT - BKT - BMgT films were studied via Rayleigh analysis. For sub-switching fields a good agreement between predicted polarization behavior from Rayleigh analysis and experimentally measured polarization indicated the validity of this approach for BNT-based thin films. Results of this thesis proved that high quality bismuth-based piezoelectric thin films with good electrical response can be fabricated with suppression of cation volatility for various processing conditions. Furthermore, these thin films can be considered as alternatives to PZT thin films as potential candidates for piezoelectric-based microelectromechanical systems (MEMS).

Jeon, Yu Hong

425

Measurement of elastic modulus and ultrasonic wave velocity by piezoelectric resonator  

NASA Astrophysics Data System (ADS)

A piezoelectric ceramic resonator is used for the ‘electrical’ measurement of elastic properties, i.e. Young’s modulus and ultrasonic wave velocity in metallic materials. Piezoelectric response is precisely calculated for the piezoelectric ceramic ring fixed at the end of a metallic rod. The piezoelectric ring serves as both an actuator as well as a sensor. The experimental setup and method of measurement using higher overtones is explained in detail and practically demonstrated for a set of different metallic materials. Young’s moduli and ultrasonic wave velocities are measured within 3% relative error. The presented method is suitable for an advanced engineering class or physics laboratory training.

Erhart, Ji?í

2015-01-01

426

Effects of doping, cation stoichiometry, and the processing conditions on the dielectric properties of high-K calcium copper titanate ceramics  

NASA Astrophysics Data System (ADS)

Since its discovery, the anomalous dielectric behavior of CaCu3 Ti4O12 (CCTO) has drawn a great deal of attention for many possible applications in electronic devices. The origin of the giant dielectric constant in CCTO was explained via an internal barrier layer capacitor model, and it has been reported that the dielectric properties of CCTO are sensitive to its microstructure which depends upon the processing conditions. To further explore its unusual dielectric phenomena, the current study focuses on the process-property-structure relationship of the high-K CCTO via doping, cation non-stoichiometry, and sintering conditions. A variety of CCTO pellets were obtained by utilizing the different processing parameters via conventional solid-state synthesis methods. For the doping study, three types of dopants were selected with the variation of doping concentration. The study of undoped CCTO ceramics was carried out by the modification of the CuO and TiO2 content in CCTO to create the stoichiometric formula CaCu3+xTi4+yO12 (x = -0.06, 0, -0.06; y = 0.08, 0, -0.08). Different processing factors including heating and cooling rates, sintering temperature, and sintering time were applied for the study of stoichiometric CCTO. X-ray diffraction, dielectric measurements, impedance spectroscopy, thermal analysis, and electron microprobe analysis were used to determine the existence of CuO and Cu2O secondary phases, dielectric constant and loss tangent, electrical resistivity of grains and boundaries, decomposition reactions, and the microstructural changes of CCTO ceramics. It was revealed that the doping method improved the dielectric constant and loss tangent. The similar improvement in dielectric properties was also found in the Cu-deficient and Ti-deficient CCTO. The measurement and characterization results of stoichiometric CCTO clearly indicated that the dielectric properties, evolution of secondary phases, and microstructures were strongly dependent upon the processing parameters. Further, CCTO became Cu-deficient and Ti-excessive regardless of sintering conditions, which provides evidence for its complex behavior created by the reduction/oxidation reactions and the defect chemistry.

Kwon, Seunghwa

427

Process for Making a Ceramic Composition for Immobilization of Actinides  

SciTech Connect

Disclosed is a process for making a ceramic composition for the immobilization of actinides, particularly uranium and plutonium. The ceramic is a titanate material comprising pyrochlore, brannerite and rutile. The process comprises oxidizing the actinides, milling the oxides to a powder, blending them with ceramic precursors, cold pressing the blend and sintering the pressed material.

Ebbinghaus, Bartley B.; Van Konynenburg, Richard A.; Vance, Eric R.; Stewart, Martin W.; Walls, Philip A.; Brummond, William Allen; Armantrout, Guy A.; Curtis, Paul G.; Hobson, Beverly F.; Farmer, Joseph; Herman, Connie Cicero; Herman, David Thomas

1999-06-22

428

Process for making a ceramic composition for immobilization of actinides  

DOEpatents

Disclosed is a process for making a ceramic composition for the immobilization of actinides, particularly uranium and plutonium. The ceramic is a titanate material comprising pyrochlore, brannerite and rutile. The process comprises oxidizing the actinides, milling the oxides to a powder, blending them with ceramic precursors, cold pressing the blend and sintering the pressed material.

Ebbinghaus, Bartley B. (Livermore, CA); Van Konynenburg, Richard A. (Livermore, CA); Vance, Eric R. (Kirrawee, AU); Stewart, Martin W. (Barden Ridge, AU); Walls, Philip A. (Cronulla, AU); Brummond, William Allen (Livermore, CA); Armantrout, Guy A. (Livermore, CA); Herman, Connie Cicero (Pleasanton, CA); Hobson, Beverly F. (Livermore, CA); Herman, David Thomas (Pleasanton, CA); Curtis, Paul G. (Tracy, CA); Farmer, Joseph (Tracy, CA)

2001-01-01

429

Nanoscale electrical probing of heterogeneous ceramics: the case of giant permittivity calcium copper titanate (CaCu3Ti4O12).  

PubMed

Scanning Probe Microscopy with conductive tips has been used to image and study the dielectric properties of giant permittivity CaCu3Ti4O12 ceramics at the nanoscale. Since measurements are generally carried out on sections of a sample, particular attention has been devoted to possible artefacts due to surface imperfections, such as substantial surface roughness and/or contamination that can result in controversial interpretation, particularly at nanometric spatial dimensions. A reliable surface investigation has been carried out after the definition of both the physical and geometrical unbiased criteria to avoid any artefacts due to surface roughness and/or anomalous tip-sample contact variations. The presence of insulating grain boundaries and the measurement of a depletion layer at the grain-grain boundary interfaces unambiguously demonstrate the relevance of the Internal Barrier Layer Capacitor effect, among all the proposed physical mechanisms, to explain the giant dielectric behaviour. Such imaging provided a clear correlation between the macroscopic dielectric properties and the nanometric structure at the interfaces. Moreover, the "general criteria" for reliable nanoelectrical characterization as well as the related measurement resolution have been defined. PMID:21240417

Fiorenza, Patrick; Raineri, Vito; Ferrarelli, Matthew C; Sinclair, Derek C; Lo Nigro, Raffaella

2011-03-01

430

Synergistic effects of aramid pulp and potassium titanate whiskers in the automotive friction material  

Microsoft Academic Search

Friction and wear of automotive brake friction materials were investigated using a pad-on-disk type friction tester to study the synergistic effects of aramid pulp (fibrillated organic fibers) and potassium titanate whiskers (fine ceramic whiskers). The friction materials were based on a simple formulation with five ingredients (phenolic resin, aramid pulp, potassium titanate whiskers, molybdenum disulfide, and barite). Friction stability, wear

S. J. Kim; M. H. Cho; D.-S. Lim; H. Jang

2001-01-01

431

Effect of cement-polymer ratio on 1-3 piezoelectric composites  

NASA Astrophysics Data System (ADS)

A 1-3 type piezoelectric composite was fabricated by cut-filling technique. The effects of cement-polymer ratio on piezoelectric and dielectric properties of the composites were analyzed. The results show that piezoelectric strain factor d33 and piezoelectric voltage factor g33 exhibit the trend of decrease initially and then increase with increasing cement-polymer ratio. With the increase of cement-polymer ratio, the dielectric factor ?r and dielectric loss tan? of the composites increase initially and then decrease. Comparing with pure piezoelectric ceramic, the mechanical quality factor Qm decreases obviously. Acoustic impedance Z is about 9 M raly, which is matching with concrete.

Guo, Lili; Xu, Dongyu; Huang, Shifeng

2009-07-01

432

www.ceramics.org | American Ceramic Society Bulletin, Vol. 92, No. 118 By Paul G. Evans and Rebecca J. Sichel-Tissot  

E-print Network

www.ceramics.org | American Ceramic Society Bulletin, Vol. 92, No. 118 By Paul G. Evans and Rebecca of piezoelectric ceramic thin films There has been rapid development in the precision with which ferroelectric mate,2 Ferroelectric thin-film materi- als belong to the broad category of electronic ceramics, and they find

Evans, Paul G.

433

Hydrogen Species Motion in Piezoelectrics: A Quasi-Elastic Neutron Scattering Study  

SciTech Connect

Hydrogen is known to damage or degrade piezoelectric materials, at low pressure for ferroelectric random access memory applications, and at high pressure for hydrogen powered vehicle applications. The piezoelectric degradation is in part governed by the motion of hydrogen species within the piezoelectric materials. We present here Quasi-Elastic Neutron Scattering (QENS) measurements of the local hydrogen species motion within lead zirconate titanate (PZT) and barium titanate (BTO) on samples charged by gaseous exposure to high-pressure gaseous hydrogen {approx}17 MPa. Filter Analyzed Neutron Spectroscopy (FANS) studies of the hydrogen enhanced vibrational modes are presented as well. Results are discussed in context of theoretically predicted interstitial hydrogen lattice sites and compared to comparable bulk diffusion studies of hydrogen diffusion in lead zirconate titanate.

Alvine, Kyle J.; Tyagi, Madhu; Brown, Craig; Udovic, Terrence J.; Jenkins, T. J.; Pitman, Stan G.

2012-03-05

434

Titanic: A Statistical Exploration.  

ERIC Educational Resources Information Center

Uses the available data about the Titanic's passengers to interest students in exploring categorical data and the chi-square distribution. Describes activities incorporated into a statistics class and gives additional resources for collecting information about the Titanic. (ASK)

Takis, Sandra L.

1999-01-01

435

Photovoltaic effect in ferroelectric ceramics  

NASA Technical Reports Server (NTRS)

The ceramic structure was simulated in a form that is more tractable to correlation between experiment and theory. Single crystals (of barium titanate) were fabricated in a simple corrugated structure in which the pedestals of the corrugation simulated the grain while the intervening cuts could be filled with materials simulating the grain boundaries. The observed photovoltages were extremely small (100 mv).

Epstein, D. J.; Linz, A.; Jenssen, H. P.

1982-01-01

436

Information Titan Parents  

E-print Network

for Parents of Commuter Students 3 Titan Parents Profile & State Relations & Advocacy 4 College Parenting 101 Titan Parents Connection President Gordon's Farewell Cal State Fullerton President Milton A. Gordon President #12;Welcome Titan Parents! On behalf of California State University, Fullerton, welcome

de Lijser, Peter

437

Your Impact. Titan Pride?  

E-print Network

Your Gift. Your Impact. How Do You Show Your Titan Pride? Cal State Fullerton Department of Intercollegiate Athletics/Titan Athletics Club 800 North State College Boulevard Fullerton,California 92834-6810 657-278-4407 / FAX 657-278-8085 Your Titan Athletics. www.fullerton.edu/tac #12;Your Gift. The choice

de Lijser, Peter

438

Tides in Titan  

NASA Technical Reports Server (NTRS)

Tides raised in Titan by Saturn give rise to a static and a periodic deformation; both will be measured with Doppler tracking during the CASSINI Tour of the Saturnian System. The latter deformation is due to the significant eccentricity of Titan's orbit and has a frequency equal to the orbital angular velocity of Titan.

Rappaport, Nicole J.

1997-01-01

439

Titan Haze  

NASA Technical Reports Server (NTRS)

The Titan haze exerts a dominating influence on surface visibility and atmospheric radiative heating at optical and near-infrared wavelengths and our desire to understand surface composition and atmospheric dynamics provides a strong motivation to study the properties of the haze. Prior to the Cassini/Huygens missions the haze was known to be global in extent, with a hemispheric contrast asymmetry, with a complicated structure in the polar vortex region poleward of about 55 deg latitude, and with a distinct layer near 370 km altitude outside of the polar vortex at the time of the Voyager 2 flyby. The haze particles measured by the Pioneer and Voyager spacecraft were both highly polarizing and strongly forward scattering, a combination that seems to require an aggregation of small (several tens of nm radius) primary particles. These same properties were seen in the Cassini orbiter and Huygens Probe data. The most extensive set of optical measurements were made inside the atmosphere by the Descent Imager/Spectral Radiometer (DISR) instrument on the Huygens Probe. At the probe location as determined by the DISR measurements the average haze particle contained about 3000 primary particles whose radius is about 40 nm. Three distinct vertical regions were seen in the DISR data with differing particle properties. Refractive indices of the particles in the main haze layer resemble those reported by Khare et al. between O.3S and about 0.7 micron but are more absorbing than the Khare et al. results between 0.7 micron and the long-wavelength limit of the DISR spectra at 1.6 micron. These and other results are described by Tomasko et al., and a broader summary of results was given by Tomasko and West,. New data continue to stream in from the Cassini spacecraft. New data analyses and new laboratory and model results continue to move the field forward. Titan's 'detached' haze layer suffered a dramatic drop in altitude near equinox in 2009 with implications for the circulation and seasonal change in the stratosphere. The book chapter associated with this talk will also present new material on thermal-infrared data analysis and on new developments in laboratory work and haze microphysical modeling.

Anderson, Carrie M.; West, Robert; Lavvas, Panayotis

2011-01-01

440

Piezoelectricity and aging effects in the PMN-PT system  

Microsoft Academic Search

PMN ceramics present piezoelectricity under an applied dc bias field. The relative dielectric permittivity varies, in general, over a wide range of values of the applied dc electric field. The purpose of this work is to study the induced piezoelectricity effect produced by an applied dc electric field in the 2.7PMN-0.1PT system assuming that the relative dielectric permittivity is a

J. Portelles; J. M. Siqueiros; A. Fundora; G. Rosario; R. Machorro; G. Hirata; F. Calderón

1999-01-01

441

Piezoelectric and electrostrictive materials for transducers applications, volume 4  

NASA Astrophysics Data System (ADS)

The topics discussed are as follows: A Study of Y1Ba2Cu3O(7-x) Thick Films on Ferroelectric Substrates; Y1Ba2Cu30(7-x) as an Electrode Material for Ferroelectric Devices; Polarization Reversal and High Dielectric Permittivity in Lead Magnesium Niobate Titanate Thin Films; Ferroelectric Switching in Lead Zirconate-Lead Zinc Niobate Thin Films; Lead Zirconate Titanate Stannate Thin Films for Large Strian Microactuator Applications; Ferroelectric Thin Film Ultrasonic Micromotors; and Piezoelectric Micromotors for Microrobots.

Cross, L. E.; Newnham, R. E.; Bhalla, A. S.; Dougherty, J. P.; Adair, J. H.; Varadan, V. K.; Varadan, V. V.

1992-01-01

442

Intensive Titan exploration begins.  

PubMed

The Cassini Orbiter spacecraft first skimmed through the tenuous upper atmosphere of Titan on 26 October 2004. This moon of Saturn is unique in our solar system, with a dense nitrogen atmosphere that is cold enough in places to rain methane, the feedstock for the atmospheric chemistry that produces hydrocarbons, nitrile compounds, and Titan's orange haze. The data returned from this flyby supply new information on the magnetic field and plasma environment around Titan, expose new facets of the dynamics and chemistry of Titan's atmosphere, and provide the first glimpses of what appears to be a complex, fluid-processed, geologically young Titan surface. PMID:15890870

Mahaffy, Paul R

2005-05-13

443

A continuous ultrasonic scanner for lumber grading  

E-print Network

ultrasonic systems today use piezoelectric transducers to generate ultrasonic waves. Commonly used piezoelectric materials are ceramics such as barium titanate (BaTi), lead zirconate titanate (PZT), and lead metaniobate (PMN) (Bray and Stanley, 1989...

Mayhew, Stephen Allison

1996-01-01

444

Electrical poling below coercive field for large piezoelectricity  

NASA Astrophysics Data System (ADS)

Isotropic polycrystalline ferroelectric ceramics have to be electrically poled to develop a net macroscopic polarization and hence piezoelectricity. It is well accepted that a sufficient poling can only be realized under an electric field that is much higher than the coercive field. In this study, we observed in (Bi1/2Na1/2)TiO3-BaTiO3 ceramics that large piezoelectricity can develop at poling fields far below the measured coercive field. Using in situ transmission electron microscopy, such an unusual behavior, is interpreted with the polarization alignment of polar nanodomains in the non-ergodic relaxor phase.

Guo, Hanzheng; Ma, Cheng; Liu, Xiaoming; Tan, Xiaoli

2013-03-01

445