Sample records for titanate piezoelectric ceramics

  1. Hydrostatic piezoelectric effect in lead titanate ceramics

    SciTech Connect

    Lopatin, S.S.; Lupeiko, T.G.; Zvyagintsev, B.I. [Rostov State Univ. (Russian Federation)] [and others

    1994-10-01

    The hydrostatic piezoelectric characteristics of Pb{sub 0.955-x}Sm{sub 2x/3}Bi{sub 0.03}Ti{sub 0.98}Mn{sub 0.02}O{sub 3} ceramics were studied. Within the range of at least 25 to 70 degrees C and at high hydrostaic and uniaxial pressures of 0.1-60 MPa, a high stability of the no-load piezoelectric voltage coefficient for the material with x=0.09-0.15 was found.

  2. Microstructure Control of Barium Titanate Grain-oriented Ceramics and Their Piezoelectric Properties

    NASA Astrophysics Data System (ADS)

    Mori, Rintaro; Nakashima, Koichi; Fujii, Ichiro; Hayashi, Hiroshi; Nagamori, Yoshitaka; Yamamoto, Yuichi; Wada, Satoshi

    2011-10-01

    The Barium titanate (BaTiO3, BT) [110] grain-oriented ceramics along [110] direction were prepared by a templated grain growth (TGG) method. The [110] oriented BT platelike particles (t-BT) were used as template particles. The relationship between poling treatment program and piezoelectric constant was investigated. The change in the poling conditions did not greatly influence domain size and the piezoelectric constant. The relationship between piezoelectric properties and domain size in BT grain-oriented ceramics was investigated. The smaller domain size was required to increase the piezoelectric constant.

  3. 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

    Hajime Nagata; Masaki Yoshida; Yoichi Makiuchi; Tadashi Takenaka

    2003-01-01

    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,

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

    NASA Astrophysics Data System (ADS)

    Ogawa, Toshio; Ikegaya, Taiki

    2015-01-01

    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.

  5. Instabilities in the piezoelectric properties of ferroelectric ceramics

    Microsoft Academic Search

    D Damjanovic; M Demartin; H. S Shulman; M Testorf; N Setter

    1996-01-01

    The large piezoelectric effect of ferroelectric ceramics is utilized in many devices for sensing and actuating purposes. In this paper, the longitudinal direct piezoelectric effect in ceramics based on lead zirconate titanate, lead titanate, barium titanate and bismuth titanate is investigated as a function of the amplitude and frequency of the external pressure, the crystal structure and microstructure of the

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

    NASA Astrophysics Data System (ADS)

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

    2007-10-01

    [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 and a high F110, the preparation conditions were optimized as functions of matrix particle size, volume fraction of the template to the matrix, and sintering temperature. As for the results, BaTiO3-grain-oriented ceramics with a high density of more than 96% were successfully prepared despite various F110 values from 0 to 98%. Scanning electron microscopy (SEM) revealed that their average grain sizes were always approximately 75 ?m despite various F110 values and there were no anisotropic microstructures. These grain-oriented BaTiO3 ceramics were poled at 100 °C, and their piezoelectric properties were measured using a resonance-antiresonance method and a piezo d33 meter for d31 and d33 piezoelectric constants. As for the results, the d31 values were almost constant at -50 pC/N despite various F110 values, while the d33 values increased with increasing F110 values, and at around an F110 of 85%, d33 reached a maximum of 788 pC/N.

  7. Piezoelectric Properties of Polycrystalline Lead Titanate Zirconate Compositions

    Microsoft Academic Search

    D. A. Berlincourt; C. Cmolik; H. Jaffe

    1960-01-01

    Detailed data are given for the piezoelectric, elastic, and dielectric properties of lead titanate zirconate ceramic compositions near the rhombohedral-tetragonal phase boundary. These compositions have markedly higher electromechanical coupling factors, remanent ferroelectric charge, and coercive field, than ceramic barium titanate. Another interesting feature is a pronounced change in the free permittivity ¿33T by the poling process; this change is in

  8. Lead Titanate and Lead Metaniobate Porous Ferroelectric Ceramics

    Microsoft Academic Search

    A. N. RYBJANETS; O. N. RAZUMOVSKAJA; L. A. REZNITCHENKO; V. D. KOMAROV; A. V. TURIK

    2004-01-01

    A manufacturing technology of porous ferroelectric ceramics on the base of pure and modified lead titanate and lead metaniobate compositions were developed. Special attention was given to the microstructure studying of porous ceramics with different porosity types. The porosity dependencies of elastic, dielectric and piezoelectric properties of the specified compositions were measured in 0–40% relative porosity range. It was shown

  9. Surface morphology and stress analysis of piezoelectric strontium-doped lead zirconate titanate thin films

    Microsoft Academic Search

    Sharath Sriram; Madhu Bhaskaran; Anthony S. Holland

    2007-01-01

    Strontium-doped lead zirconate titanate (PSZT) is a piezoelectric ceramic with relatively high values of piezoelectric coefficients. Perovskite oriented PSZT thin films are also reported to exhibit a variety of other properties including ferroelectricity and pyroelectricity. This paper reports on a study of the surface morphology and resulting stress of PSZT thin films, deposited under a variety of RF magnetron sputtering

  10. Piezoelectric properties of some lead-free ferroelectric ceramics

    Microsoft Academic Search

    Tadashi Takenaka

    1999-01-01

    The use of lead-free materials in piezoelectric ceramics has recently become a very important issue in environmental protection of the earth. Some lead-free piezoelectric materials, namely bismuth sodium titanate, (Bi1\\/2Na1\\/2)TiO3 (BNT) – based solid solution ceramics, such as (1-a)BNT-a·BaTiO3 [BNBT], (1-b)BNT-b·NaNbO3 [BNTN] and a(Bi1\\/2Na1\\/2)TiO3-bKNbO3-c1\\/2(Bi2O3·Sc2O3) [KTNS] (a+b+c=1) systems, were studied for their dielectric, ferroelectric and piezoelectric properties as candidates for a

  11. Compositional effect on piezoelectric and anomalous photovoltaic properties of PLZT ceramics with fixed grain sizes

    Microsoft Academic Search

    Jing-Feng Li; Daming Cheng

    2008-01-01

    Lanthanum-modified lead zirconate titanate (PLZT) ceramics possess the photostrictive effect applicable to photo-driven and\\u000a wireless actuators. The piezoelectric and anomalous photovoltaic (APV) properties of PLZT ceramics with different compositions\\u000a but the same grain size were evaluated to investigate the intrinsic compositional effects. After the adjustment of the sintering\\u000a temperature and soaking time, the grain sizes of PLZT ceramics with different

  12. Piezoelectric response and origin in ,,001... Pb,,Mg1/3Nb2/3...0.70Ti0.30O3 crystal C.-S. Tu,1,a

    E-print Network

    piezoelectric coefficients compared with lead zirconic titanate ceramics.1 Ferroelectric FE and piezoelectric Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China

  13. COLD SPRAY ELECTRODING OF PIEZOELECTRIC CERAMIC

    Microsoft Academic Search

    P. C. King; S. H. Zahiri; M. Jahedi; J. Friend

    Lead zirconate titanate (PZT) is a piezoelectric material that is used in a wide range of applications from small actuators for the precise movement of lenses and mirrors to ultrasonic generators for the industrial mixing and emulsification of liquids. Conventional bonding of PZT involves the use of adhesives which dampen the movement of the element. This paper is a summary

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

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

    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.

  15. Mechanical Reinforcement and Piezoelectric Properties of PZT Ceramics Embedded with NanoCrystalline

    Microsoft Academic Search

    Da-Wei Wang; Hai-Bo Jin; Jie Yuan; Bao-Li Wen; Quan-Liang Zhao; De-Qing Zhang; Mao-Sheng Cao

    2010-01-01

    The double-scale lead zirconate titanate (PZT) piezoelectric ceramics were prepared by the solid state processing with PZT nano-crystalline and micro-powder. The microstructures, electrical and mechanical properties of the double-scale PZT are investigated. All the sintered ceramics exhibit a single perovskite structure and the grain size of the double-scale PZT reduces due to the incorporation of PZT nano-crystalline. Compared to normal

  16. Mechanical Reinforcement and Piezoelectric Properties of PZT Ceramics Embedded with Nano-Crystalline

    NASA Astrophysics Data System (ADS)

    Wang, Da-Wei; Jin, Hai-Bo; Yuan, Jie; Wen, Bao-Li; Zhao, Quan-Liang; Zhang, De-Qing; Cao, Mao-Sheng

    2010-04-01

    The double-scale lead zirconate titanate (PZT) piezoelectric ceramics were prepared by the solid state processing with PZT nano-crystalline and micro-powder. The microstructures, electrical and mechanical properties of the double-scale PZT are investigated. All the sintered ceramics exhibit a single perovskite structure and the grain size of the double-scale PZT reduces due to the incorporation of PZT nano-crystalline. Compared to normal PZT, the mechanical properties increase significantly and the piezoelectric properties decrease slightly. Mechanisms responsible for the reinforcement of the double-scale PZT are discussed.

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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.

  18. Novel piezoelectric ceramics: Development of high temperature, high performance piezoelectrics on the basis of structure

    NASA Astrophysics Data System (ADS)

    Eitel, Richard E.

    A new family of morphotropic phase boundary (MBP) perovskite solid solutions based on (1-x)BiMeO3-xPbTiO3 has been discovered. These materials promise both high piezoelectric properties, characteristic of MPB systems, and usage temperatures unavailable in current high performance piezoelectric systems. The discovery of this family of bismuth perovskite-lead titanate materials was made using simple crystal chemistry arguments based on the perovskite tolerance factor. In the current work, the details of the (1-x)BiScO3-xPbTiO3 (BSxPT) solid solution will be presented as the "prototype" example of this new family of materials. The optimum processing conditions and electromechanical properties of the BSxPT system were determined. X-ray diffraction, electron microscopy, dielectric measurements, and calorimetery were used to determine the details of the phase diagram, crystal structure, and domain structure. The intrinsic and extrinsic contributions to the dielectric and piezoelectric properties were determined using cryogenic dielectric measurements and a novel application of the Rayleigh Law to the direct piezoelectric response. The nature of the phase transition behavior in the tetragonal region of the BSxPT phase diagram was explored based on the Landau phenomenological approach. The BSxPT system represents a breakthrough in the field of piezoelectric ceramics. For the first time ever, a MPB piezoelectric material system has been developed with a transition temperature higher than Pb(Zr,Ti)O3 and improved piezoelectric properties. A detailed understanding of the structure, electromechanical response, and phase transition behavior of this exciting new system has been obtained. Further, a roadmap for the continued development of new materials in the family (1-x)BiMeO3-xPbTiO 3 was developed.

  19. Piezoelectric ceramics and ceramic composites for intelligent mechanical behaviors

    SciTech Connect

    Wang, Hongyu; Singh, R.N. [Univ. of Cincinnati, OH (United States)

    1994-12-31

    Crack propagation in piezoelectric PZT ceramics under applied static electric fields has been studied using the Vickers indentation technique in an effort to develop the intelligent mechanical responses of ferroelectric ceramics and ceramic composites. It was observed that crack lengths decreased under a positive applied field (the polarity of the applied electric field was the same as that for poling) and increased under a negative applied field. Such an effect became more profound with increasing field strength. These observations were in contrary to tile expectation based on the piezoelectric characteristics of PZT ceramics. The direction of surface polishing had little effect on the crack extension behavior. More work is being done to further investigate the mechanisms for the observed behavior, including the possibility of a 180{degrees} domain switching in the surface layer because of the surface polishing.

  20. A study on (K, Na) NbO3 based multilayer piezoelectric ceramics micro speaker

    NASA Astrophysics Data System (ADS)

    Gao, Renlong; Chu, Xiangcheng; Huan, Yu; Sun, Yiming; Liu, Jiayi; Wang, Xiaohui; Li, Longtu

    2014-10-01

    A flat panel micro speaker was fabricated from (K, Na) NbO3 (KNN)-based multilayer piezoelectric ceramics by a tape casting and cofiring process using Ag-Pd alloys as an inner electrode. The interface between ceramic and electrode was investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). The acoustic response was characterized by a standard audio test system. We found that the micro speaker with dimensions of 23 × 27 × 0.6 mm3, using three layers of 30 ?m thickness KNN-based ceramic, has a high average sound pressure level (SPL) of 87 dB, between 100 Hz-20 kHz under five voltage. This result was even better than that of lead zirconate titanate (PZT)-based ceramics under the same conditions. The experimental results show that the KNN-based multilayer ceramics could be used as lead free piezoelectric micro speakers.

  1. Piezoelectric ceramics for high reliability ring laser gyros

    Microsoft Academic Search

    W. B. Harrison; R. G. Langton

    1988-01-01

    Piezoelectric ceramic micropositioning transducers and dithering motors have been used extensively in ring laser gyros (RLG) supplied to DOD and Commercial Avionics customers. The three applications for these elements are path length control (PLC) transducers, dither motor piezoelectric bender elements and dither motor sensors. This paper will review the operation of the RLG and the unique piezoelectric ceramics used, and

  2. Dielectric and Piezoelectric Properties of Barium Titanate

    Microsoft Academic Search

    Shepard Roberts

    1947-01-01

    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

  3. Product property between thermal expansion and piezoelectricity in piezoelectric ceramic-polymer composites

    Microsoft Academic Search

    Xiaoping Zou; Liangying Zhang; Xi Yao; Likun Wang; Fuxue Zhang

    1996-01-01

    The product property between thermal expansion and piezoelectricity in composites prepared from piezoelectric ceramics and polymers is presented. A theoretical analysis on the product property is discussed based on series and parallel models of the composites. From the theoretical analysis, the necessary condition for the highest product effect of diphasic composites is discussed. Composites with piezoelectric ceramic PZT particles, TGS

  4. Effects of thickness on the piezoelectric and dielectric properties of lead zirconate titanate thin films

    E-print Network

    Sottos, Nancy R.

    Effects of thickness on the piezoelectric and dielectric properties of lead zirconate titanate thin Lead zirconate titanate PZT thin films with a Zr/Ti ratio of 52/48 were deposited on platinized silicon

  5. Elastic and Piezoelectric Coefficients of Single-Crystal Barium Titanate

    Microsoft Academic Search

    Don Berlincourt; Hans Jaffe

    1958-01-01

    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

  6. Effect of surface modification of lead zirconate titanate particles on the properties of piezoelectric composite sensors

    NASA Astrophysics Data System (ADS)

    Saber, Nasser; Ma, Jun; Hsu, Hung-Yao; Lee, Sang-Heon; Marney, Donavan

    2013-08-01

    Piezoelectric composite sensors which consist of a ferroelectric ceramic phase and a polymer binder have been the center of interest for offering a distributed sensing mechanism in many industrial applications. This study investigates the effect of PZT surface modification on the mechanical and piezoelectric properties of PZT/epoxy composite sensors. Lead zirconate titanate ceramic powder (PZT-5H) was surface modified to prepare a high PZT content (0-3) piezoelectric composite sensor. Functional groups of the modifiers grafted onto the PZT particle surface served as a bridge into the epoxy matrix, thus creating strong bonds between the matrix and PZT particles. This noticeably improved the dispersion of the PZT phase, allowing the use of large fractions of piezoactive component in the composite. It is demonstrated that the produced piezo-film shows an enhanced poling behavior in that it can be poled with lower voltages under reduced poling times. This is caused by greater levels of microstructural homogeneity in the modified films as well as alteration of interfacial charge characteristics using modifiers' functional groups.

  7. High temperature thickness measurements using a bismuth titanate piezoelectric transducer

    NASA Astrophysics Data System (ADS)

    Burrows, S. E.; McAughey, K. L.; Edwards, R. S.; Dixon, S.

    2012-05-01

    Bismuth titanate Bi4Ti3O12 was prepared through a sol-gel process, characterised and built as a high temperature ultrasound transducer. Platinum electrodes and wires were used throughout for high temperature stability and Pyrogel 100 used as couplant. The piezoelectric coefficient was found to be stable to 550C. Repeatable thickness measurements were made up to 250°C on aluminium and steel test samples using a pulse-echo technique and the efficiency of the transducer studied under thermal cycling.

  8. High-Temperature Piezoelectric Ceramic Developed

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    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.

  9. Behavior of soft piezoelectric ceramics under high sinusoidal electric fields

    NASA Astrophysics Data System (ADS)

    Kugel, V. D.; Cross, L. E.

    1998-09-01

    The behavior of piezoelectric, dielectric, and elastic characteristics of soft piezoelectric lead zirconate titanate (PZT) ceramics was investigated under sinusoidal electric field E applied along the poling direction and under mechanical stress-free conditions for a frequency range 10 Hz-10 kHz. Electrical displacement D3 along the poling direction, mechanical strain S1 in the direction perpendicular to the poling direction, and the resonant frequency ?r of electromechanically uncoupled bending vibrations of polarized plates were measured. Commercial ceramics PZT5H, 3203HD, and PKI550 with chemical composition near the morphotropic phase boundary were used in the study. It was found that the amplitude and phase of the first harmonic of the relative strain S1(1)/Em and of the relative electrical displacement D3(1)/Em increase similarly with increasing amplitude Em of the electric field if the amplitude is less than coercive field. The corresponding increase in the square of the resonant frequency is more moderate. The dependencies are described well by linear functions except for low electric fields. The functions S1m(1)/Em and D3m(1)/Em demonstrate frequency dispersion as well. Relative amplitude of the second harmonic of the electrical displacement, D3m(2)/D3m(1), which is polar, also increases almost linearly with increasing Em. The relative third harmonic D3m(3)/D3m(1) demonstrates saturationlike behavior. By means of the electric pulse technique, it was found that irreversible changes in the remnant polarization take place even at electric fields much smaller that the coercive field. A mathematical model of a hysteretic transducer, describing the electric field dependence of electromechanical properties of soft piezoelectric PZT ceramics, was suggested. According to this approach, the response depends not only on the instantaneous magnitude of the input signal (e.g., electric field) but also on its past extreme values. It was shown that the experimental Rayleigh law is a particular case of the suggested approach. The model relates directly electric field dependencies of complex piezoelectric coefficient d31(Em) and S1(1)/Em, of complex dielectric permittivity ?33T(Em) and D3(1)/Em, and of the amplitude of elastic compliance s11E(Em) and ?r2. Application of the model to experimental data showed that the model describes well the first three complex harmonics of D3 and the irreversible change in the remnant polarization. Physical causes of the observed behavior were analyzed. As an alternative to the model based on the 90° polarization reorientation and tetragonal/rhombohedral phase boundary motion, a new approach was suggested. In this model, the observed hysteretic changes in the electromechanical properties are assumed to be caused by the electric field dependency of the mechanical stress acting at interdomain boundaries in the partly constrained crystallites of these ceramics.

  10. Effects of the poling process on dielectric, piezoelectric, and ferroelectric properties of lead zirconate titanate

    NASA Astrophysics Data System (ADS)

    Prewitt, Anderson D.

    Smart materials are widely used in many of today's relevant technologies such as nano and micro electromechanical systems (NEMS and MEMS), sensors, actuators, nonvolatile memory, and solid state devices. Many of these systems rely heavily on the electromechanical properties of certain smart materials, such as piezoelectricity and ferroelectricity. By definition, piezoelectricity is a mechanical stress in a material that produces an electric displacement (known as the direct piezoelectric effect) or electrical charge in a material which produces a mechanical strain (known as the converse piezoelectric effect). Ferroelectricity is a sub-class of piezoelectricity in which the polarization occurs spontaneously and the dipoles can be reoriented. Domain walls are the nanoscale regions separating two finite distinctively polarized areas in a ferroelectric. The reorientation of polarization in a material is called the poling process and many factors can influence the effectiveness of this process. A more fundamental understanding of how electrical and mechanical loading changes the domain structure of these materials could lead to enhanced properties such as increased energy transduction and decreased nonlinear behavior. This research demonstrates the influence of mechanical pressure and electrical field during and after the poling process on domain walls. The effects of strong mechanical forces on large-scale domain switching and weak cyclic forces on small-scale domain wall motion are investigated to show how they affect the macroscopic behavior of these materials. Commercial lead zirconate titanate ceramics were studied under various poling conditions and the effect of domain wall motion on the piezoelectric, dielectric, and ferroelectric properties was investigated. Polarization and strain measurements from samples poled at specific conditions and converse piezoelectric coefficient and dielectric permittivity data was extracted and interpreted in the context of Rayleigh Law. Direct d33 was also measured. Mechanical loading measurements on the samples were conducted in situ during neutron diffraction experiments to determine how the domain structure behaved for the various poling conditions. The behavior of unpoled and poled samples under load was investigated. The goal of this research is to develop a better understanding of the ferroelectric poling process and its influence on domain wall behavior in order to better engineer material and device properties. Experimental results have shown that significant changes occur in the electromechanical behavior of the material depending on the poling conditions. These results provide insight on how to better design materials and devices with enhanced performance, improved capacity, and less degradation as a result of mechanical stress and electrical fields. Possible microstructural origins for this behavior are discussed.

  11. Preparation and piezoelectric properties of potassium sodium niobate glass ceramics

    NASA Astrophysics Data System (ADS)

    Jiang, Shan; Wang, Xuan-Ming; Li, Jia-Yu; Zhang, Yong; Zheng, Tao; Lv, Jing-Wen

    2015-06-01

    This paper describes the preparation of a piezoelectric glass ceramic material from potassium sodium niobate (K0.5Na0.5NbO3; KNN) using a novel melting method. The effects of the subsequent heat-treatment on the optical, thermal, electrical, and mechanical properties of the material are carefully examined, and its crystal structure and surface morphology are characterized respectively by x-ray diffraction and scanning electron microscopy. This new material has a much higher piezoelectric coefficient (163 pC·N?1) than traditional piezoelectric ceramics (131 pC·N?1). On this basis therefore, a strategy for the future study and development of lead-free KNN-based piezoelectric glass ceramics is proposed.

  12. PTCR-NTCR composite behavior of bismuth titanate ceramics

    NASA Astrophysics Data System (ADS)

    Sharanappa, Nagbasavanna; Madolappa, Shivanand; Sagar, Raghavendra; Raibagkar, R. L.

    2013-06-01

    In this paper, we report the synthesis of bismuth titanate (Bi4Ti3O12, BiT) ceramics by solid state reaction method. Structural and electrical properties were studied for phase and temperature coefficient of resistance, respectively. A single phase orthorhombic structure of bismuth titanate was observed. Sample shows mixed temperature coefficient of resistance behavior, exhibiting negative TCR (NTCR) in the beginning and later positive TCR (PTCR). This kind of unusual (?-T) behavior was accounted for core-shell microstructure. The result of TGA-DSC showed the crystallization temperature of these ceramic samples.

  13. Adhesion of electrolessly deposited nickel on lead zirconate titanate ceramic

    SciTech Connect

    Baumgartner, C.E. (General Electric Co., Schenectady, NY (United States). Corporate Research and Development Center)

    1989-06-01

    This paper reports on electrolessly deposited Ni onto lead zirconate titanate (PZT) ceramic measured as a function of both the ceramics surface preparation prior to metalization and the plated Ni thickness. A maximum in Ni/PZT interfacial adhesion of approximately 27 kg/cm{sup 2}, as measured by a pull test, occurs when the ceramic grain boundaries are chemically etched, thereby providing points to mechanically anchor the Ni deposit. The adhesion decreases with over-etching as the ceramic grains are undercut and drops off dramatically with increasing plated Ni thickness.

  14. Piezoelectric generation of longitudinal waves in strontium titanate at cryogenic temperatures

    Microsoft Academic Search

    R. Nava; R. Oentrich

    1998-01-01

    Thin single-crystal plates of strontium titanate (STO) have been used as non-resonant surface excited piezoelectric transducers to launch longitudinal ultrasonic waves into rutile crystals at low-temperatures for frequencies as high as 500 MHz. In contrast to the recently discovered giant static piezoelectric effect which shows a strong increase on the piezoelectric strain constant d311 in the quantum paraelectric regime of

  15. Piezoelectric Properties of Pure and Mn-doped Potassium Niobate Ferroelectric Ceramics

    Microsoft Academic Search

    Kenji Matsumoto; Yuji Hiruma; Hajime Nagata; Tadashi Takenaka

    2006-01-01

    Potassium niobate, KNbO3 (KN), ceramics doped with manganese (Mn) were prepared by the conventional ceramic fabrication process to characterize their electrical properties. The difficulty in obtaining dense ceramics by conventional methods limits our knowledge of the piezoelectricity of this ceramic. In this paper, an optimized process for obtaining dense (over 95%) and nondeliquescent KN ceramics is described. Dielectric and piezoelectric

  16. Surface morphology and stress analysis of piezoelectric strontium-doped lead zirconate titanate thin films

    NASA Astrophysics Data System (ADS)

    Sriram, Sharath; Bhaskaran, Madhu; Holland, Anthony S.

    2006-12-01

    Strontium-doped lead zirconate titanate (PSZT) is a piezoelectric ceramic with relatively high values of piezoelectric coefficients. Perovskite oriented PSZT thin films are also reported to exhibit a variety of other properties including ferroelectricity and pyroelectricity. This paper reports on a study of the surface morphology and resulting stress of PSZT thin films, deposited under a variety of RF magnetron sputtering conditions. The study compares PSZT thin films deposited on metal (gold and platinum) coated silicon wafers. The surface morphology of the deposited PSZT thin films was studied using Atomic Force Microscopy (AFM). Grain size and average surface roughness measurements were used to study the quality of the films. The thin film stress was determined using the changes in the radius of curvature of the sample due to an added layer of thin film, and by applying Stoney's equation to relate the stress to the radius of curvature. The variations in the level of stress for different thermodynamic conditions during RF magnetron sputter deposition are also reported.

  17. EFFECT OF NIOBIUM DOPING ON PIEZOELECTRIC AND PYROELECTRIC PROPERTIES OF Bi3.5Nd0.5Ti3O12 CERAMICS

    Microsoft Academic Search

    T. T. HU; K. W. KWOK; H. L. W. CHAN; C. L. CHOY

    2006-01-01

    Niobium-doped bismuth titanate (Bi3.5?x\\/3Nd0.5Ti3?xNbxO12, x = 0 to 0.09) were prepared using a conventional mixed oxide method, and the effects of Nb doping on the dielectric, ferroelectric, piezoelectric and pyroelectric properties of the ceramics were examined. In general, the doping with Nb decreases the relative permittivity ?, coercive field Ec and leakage current density J of the ceramics, while increases

  18. Large effective-strain piezoelectric actuators using nested cellular architecture with exponential strain amplification mechanisms

    E-print Network

    Ueda, Jun

    Design and analysis of piezoelectric actuators having over 20% effective strain using an exponential strain amplification mechanism are presented in this paper. Piezoelectric ceramic material, such as lead zirconate titanate ...

  19. Plasma crystallization of polymer-ferroelectric/piezoelectric ceramic composites and their piezoelectric properties

    NASA Astrophysics Data System (ADS)

    Kurbanov, M. A.; Sultanakhmedova, I. S.; Kerimov, É. A.; Aliev, Kh. S.; Aliev, G. G.; Ge?darov, G. M.

    2009-06-01

    The crystallization of “polymer-ferroelectric/piezoelectric ceramic” composites under the action of an electric discharge plasma and temperature is investigated. It is shown that this process results in strong oxidation of polymer chains. The oxidation of polymer chains is accompanied by an enhancement of interfacial interactions and an increase in the concentration of charge localization centers or the number of local levels in the quasi-band gap of the polymer phase, which upon polarization leads to an increase in interfacial charges. These charges and oxidation of polymer chains favor the effective polarization of piezoelectric phase domains and, hence, an increase in the piezoelectric parameters of the composite.

  20. Piezoelectric Properties of BaTiO3-(Bi1\\/2K1\\/2)TiO3 Ferroelectric Ceramics

    Microsoft Academic Search

    Yuji Hiruma; Rintaro Aoyagi; Hajime Nagata; Tadashi Takenaka

    2004-01-01

    The dielectric, ferroelectric and piezoelectric properties of barium titanate (BaTiO3)-based solid solution, (1-x)BaTiO3-x(Bi1\\/2K1\\/2)TiO3 (0<= x<= 1) (BT-BKT100x), a candidate lead-free piezoelectric ceramic, were studied using a starting material of fine BaTiO3 powder. The Curie temperature, Tc, of the BT-BKT ceramics shifted to higher temperatures than those of BT with increasing the amount (x) of (Bi1\\/2K1\\/2)TiO3 and Tc was higher than

  1. Characterization of Hard Piezoelectric Lead-Free Ceramics

    PubMed Central

    Zhang, Shujun; Lim, Jong Bong; Lee, Hyeong Jae; Shrout, Thomas R.

    2010-01-01

    K4CuNb8O23 doped K0.45Na0.55NbO3 (KNN-KCN) ferroelectric ceramics were found to exhibit asymmetrical polarization hysteresis loops, related to the development of an internal bias field. The internal bias field is believed to be the result of defect dipoles of acceptor ions and oxygen vacancies, which lead to piezoelectric “hardening” effect, by stabilizing and pinning of the domain wall motion. The dielectric loss for the hard lead-free piezoelectric ceramic was found to be 0.6%, with mechanical quality factors Q on the order of >1500. Furthermore, the piezoelectric properties were found to decrease and the coercive field increased, when compared with the undoped material, exhibiting a typical characteristic of “hard” behavior. The temperature usage range was limited by the polymorphic phase transition temperature, being 188°C. The full set of material constants was determined for the KNN-KCN materials. Compared with conventional hard PZT ceramics, the lead-free possessed lower dielectric and piezoelectric properties; however, comparable values of mechanical Q, dielectric loss, and coercive fields were obtained, making acceptor modified KNN based lead-free piezoelectric material promising for high-power applications, where lead-free materials are desirable. PMID:19686966

  2. Experiments to demonstrate piezoelectric and pyroelectric effects

    NASA Astrophysics Data System (ADS)

    Erhart, Ji?í

    2013-07-01

    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 change. The direct piezoelectric effect is demonstrated by the electric charge generated from the bending of the piezoelectric ceramic membrane or from the gas igniter. The converse piezoelectric effect is presented in the experiments by the deflection of the bending piezoelectric element (piezoelectric bimorph).

  3. Effects of WO 3 additions on the phase structure and transition of zinc titanate ceramics

    Microsoft Academic Search

    Xiangchun Liu; Ming Zhao; Feng Gao; Lili Zhao; Changsheng Tian

    2008-01-01

    WO3-doped zinc titanate ceramics were prepared by conventional mixed-oxide method combined with a chemical processing. The effects of WO3 additions on the phase structure and phase transitions of zinc titanate ceramics were investigated by high-temperature X-ray diffractometry (HTXRD) and transmission electron microscopy (TEM). The results showed that the major phase of zinc titanate ceramics transformed from zinc orthotitanate phase to

  4. Dielectric behavior of barium modified strontium bismuth titanate ceramic

    NASA Astrophysics Data System (ADS)

    Nayak, P.; Badapanda, T.; Anwar, S.; Panigrahi, S.

    2014-04-01

    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 Ba2+ ion, may be due to the decrease of orthorhombicity by the incorporation of Ba2+ ion in SBT lattice.

  5. Microstructure and properties of nanosructured strontium lead titanate ceramic

    Microsoft Academic Search

    Xiao-hui Wang; Tianling Ren; Zhilun Gui; Longtu Li

    2001-01-01

    Nanostructured ceramics of strontium lead titanate (Pb0.5Sr0.5TiO3) were obtained by fast-sintering at 1150°C ?1200°C from nanosize powder prepared by stearic acid gel method. The microstructure was characterized by means of X-ray diffraction, scanning electronic microscopy, transmission electronic microscopy, atom force microscopy and phase detection microscopy. The size effect on structure as well as ferroelectric property was investigated. The phase transition

  6. Plasma crystallization of polymer-ferroelectric\\/piezoelectric ceramic composites and their piezoelectric properties

    Microsoft Academic Search

    M. A. Kurbanov; I. S. Sultanakhmedova; É. A. Kerimov; Kh. S. Aliev; G. G. Aliev; G. M. Geidarov

    2009-01-01

    The crystallization of ``polymer-ferroelectric\\/piezoelectric ceramic'' composites under the action of an electric discharge plasma and temperature is investigated. It is shown that this process results in strong oxidation of polymer chains. The oxidation of polymer chains is accompanied by an enhancement of interfacial interactions and an increase in the concentration of charge localization centers or the number of local levels

  7. Strontium doped lead zirconate titanate ceramics: study of calcination and sintering process to improve piezo effect.

    PubMed

    Khalid, Muhammad; Shoaib, Muhammad; Khan, Amir Azam

    2011-06-01

    Perovskite crystal structure is found in many ionic solids like CaTiO3, BaTiO3 and Lead Zirconate Titanates (PZT). In this structure off-center position of cations in oxygen octahedral causes polarization and produces direct and indirect piezoelectric responses in ceramic materials that are suitable for many ultrasonic applications. In the present study 9% Sr doped PZT ceramics were prepared and their dielectric and piezoelectric properties measured. X ray Diffraction (XRD) analysis of calcined powders demonstrated a decrease in the PbO content during the calcination stage at 850 degrees C. This was counterbalanced by adding excess PbO at the time of preparation of mixtures. Sintering was carried out at 1200 degrees C for 2 hours in lead rich atmosphere. The properties achieved were Dielectric Constant (K) = 1440, Tangent Loss (Tan delta) = 0.0062, Charge Coefficient (d33) = 335 pC/N and density = 7.55 g/cm3. SEM analysis of sintered samples demonstrated that grain size was 2-3 microm with clean grain boundaries and no large size porosity observed. XRD analysis of sintered pellets exhibited that material prepared was free of any precipitated phase usually harmful for the piezo effect. PMID:21770202

  8. Unfolding grain size effects in barium titanate ferroelectric ceramics

    PubMed Central

    Tan, Yongqiang; Zhang, Jialiang; Wu, Yanqing; Wang, Chunlei; Koval, Vladimir; Shi, Baogui; Ye, Haitao; McKinnon, Ruth; Viola, Giuseppe; Yan, Haixue

    2015-01-01

    Grain size effects on the physical properties of polycrystalline ferroelectrics have been extensively studied for decades; however there are still major controversies regarding the dependence of the piezoelectric and ferroelectric properties on the grain size. Dense BaTiO3 ceramics with different grain sizes were fabricated by either conventional sintering or spark plasma sintering using micro- and nano-sized powders. The results show that the grain size effect on the dielectric permittivity is nearly independent of the sintering method and starting powder used. A peak in the permittivity is observed in all the ceramics with a grain size near 1??m and can be attributed to a maximum domain wall density and mobility. The piezoelectric coefficient d33 and remnant polarization Pr show diverse grain size effects depending on the particle size of the starting powder and sintering temperature. This suggests that besides domain wall density, other factors such as back fields and point defects, which influence the domain wall mobility, could be responsible for the different grain size dependence observed in the dielectric and piezoelectric/ferroelectric properties. In cases where point defects are not the dominant contributor, the piezoelectric constant d33 and the remnant polarization Pr increase with increasing grain size. PMID:25951408

  9. Mn and Sm doped lead titanate ceramic fibers and fiber/epoxy 13 composites

    NASA Astrophysics Data System (ADS)

    Li, Kun; Pang, Geoffrey; Wa Chan, Helen Lai; Choy, Chung Loong; Li, Jin-hua

    2004-05-01

    Manganese and samarium doped lead titanate [Pb0.85Sm0.10(Ti0.98Mn0.02)O3, PSmT] fibers were prepared by sol-gel method. The micrographs obtained using scanning electron microscope show that PSmT ceramic fibers are round and dense. The diameter of the fibers was in the range of 30-35 ?m. The crystalline grains size is ˜2.5 ?m. The micrographs obtained using transmission electron microscope also unveiled the layer-by-layer 90° domains in the grains. X-ray diffraction patterns of the fibers show that PSmT ceramics have a pure perovskite structure. The c/a ratio of the unit cell was 1.04. The PSmT fiber/epoxy 1-3 composites were fabricated by filling the ceramic fiber bundle with epoxy. The dielectric permittivity ?, electromechanical coefficient kt, and the piezoelectric constant d33 of PSmT fiber/epoxy 1-3 composites with 68% fiber loading were 118, 0.51, and 48 pC/N, respectively. The hysteresis loop of the composites was measured by the Sawyer-Tower method. It was also found that the composites could withstand an electric field of 15 kV/mm at room temperature.

  10. Plasma crystallization of polymer-ferroelectric\\/piezoelectric ceramic composites and their piezoelectric properties

    Microsoft Academic Search

    M. A. Kurbanov; I. S. Sultanakhmedova; É. A. Kerimov; Kh. S. Aliev; G. G. Aliev; G. M. Ge?darov

    2009-01-01

    The crystallization of “polymer-ferroelectric\\/piezoelectric ceramic” composites under the action of an electric discharge\\u000a plasma and temperature is investigated. It is shown that this process results in strong oxidation of polymer chains. The oxidation\\u000a of polymer chains is accompanied by an enhancement of interfacial interactions and an increase in the concentration of charge\\u000a localization centers or the number of local levels

  11. Realization of high-energy density polycrystalline piezoelectric ceramics

    SciTech Connect

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

    2006-01-16

    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.

  12. Phase diagram and enhanced piezoelectricity in the strontium titanate doped potassium-sodium niobate solid solution

    Microsoft Academic Search

    Ruiping Wang; Rong-Jun Xie; Kotaro Hanada; Kunio Matsusaki; Hiroshi Bando; Mitsuru Itoh

    2005-01-01

    The dielectric and the piezoelectric properties of the (1-x)(Na0.5K0.5)NbO3-xSrTiO3 ceramics, densified by the Spark-Plasma-Sintering method, have been studied. A phase diagram was established from the temperature dependence of the dielectric constant. A tetragonal-orthorhombic morpho-tropic phase boundary (MPB) was found at x 0.05. Around the MPB, piezoelectric properties were greatly improved. The origin for the enhanced piezoelectricity has been proposed.

  13. Residual ferroelectricity, piezoelectricity, and flexoelectricity in barium strontium titanate tunable dielectrics

    NASA Astrophysics Data System (ADS)

    Garten, Lauren M.

    Loss reduction is critical to the development of Ba 1-xSrxTiO3 (BST) thin film tunable microwave dielectrics. This work addresses mechanisms of loss and performance of Ba1-xSr xTiO3, such as residual ferroelectricity, enhanced flexocoupling, and dc electric field induced piezoelectricity. The presence of residual ferroelectricity --a persistent ferroelectric response above the global phase transition temperature, adds a contribution to dielectric loss from either motion of domain walls or the boundaries of micropolar regions, degrading the tunable performance over a wide frequency range. Rayleigh behavior as a function of temperature was used to track the ferroelectric behavior of BST materials through the ferroelectric to paraelectric transition temperature. The irreversible Rayleigh parameter serve as a metric for the presence of ferroelectricity because this response is dependent on the presence of domain walls, cluster boundaries or phase boundaries. Chemical solution deposited Ba0.7Sr0.3TiO3 films, with relative tunabilities of 86% over 250kV/cm at 100kHz, demonstrated residual ferroelectricity at least 65°C above the ostensible paraelectric transition temperature. The Rayleigh behavior was further corroborated with second harmonic generation, polarization-electric field hysteresis loops and the frequency dependence of the Rayleigh response. The temperature extent of residual ferroelectricity in sputtered and chemical solution deposited films and bulk ceramics was investigated as a function of chemical inhomogeneity on the A-site using electron energy loss spectroscopy. All samples showed some residual ferroelectricity, where the temperature extent was a function of the sample processing. The application of AC electric field for residual ferroelectric measurements of these samples lead to a 100% increase in loss for ac fields exceeding 10kV/cm at room temperature. The presence of residual ferroelectricity in BST also correlates to the increased flexoelectric response in these materials. Residual ferroelectricity is observed in barium strontium titanate ceramics 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 in this temperature range was shown to lead to strain gradient-induced poling, or flexoelectric poling, enhancing the flexoelectric response. Flexoelectric poling was observed by the development of a remanent polarization in flexoelectric measurements upon the removal of the applied strain gradient. Additionally, an induced d33 piezoelectric response was observed in samples after the removal of the applied strain gradient, indicating that the polarization was realigned during flexoelectric measurements. Flexoelectric poling lead to the production of an internal bias of 9 kV/m. It is concluded that residual ferroelectric response considerably enhances the observed flexoelectric response. In order to investigate the effects of dc electric field induced piezoelectricity, metrology was designed, developed and calibrated for the measurement of the e31,f piezoelectric coefficient as a function of applied electric field and strain. This allowed for direct measurements of the field-induced piezoelectric response for Ba0.7Sr0.3TiO3 (70:30) and Ba 0.6Sr0.4TiO3 (60:40) thin films on MgO and silicon. The relative dielectric tunabilities for the 70:30 and 60:40 composition on MgO were 83% and 70% respectively, with a dielectric loss of 0.011 and 0.004 at 100 kHz respectively. A linear increase in induced piezoelectricity with field to --3.0 C/m2 and --1.5 C/m2 at 110 kV/cm was observed in 60:40 BST on MgO and 70:30 BST on Si. Large and hysteretic piezoelectric and tuning responses were observed in the 70:30 BST thin films on MgO. This was consistent with the irreversible Rayleigh behavior, indicating a ferroelectric contribution to the piezoelectric and dielectric response 40°C above the global paraelectric transition temperature. This information should enable advancements in tunable

  14. PLZT-based photovoltaic Piezoelectric Transformer with light feedback

    Microsoft Academic Search

    L. Kozielski; M. Adamczyk; J. Erhart

    2011-01-01

    Piezoelectric Transformer (PT) converts an electrical AC input voltage into ultrasonic vibrations and reconverts back to an output as AC voltage. Hard lead zirconate titanate (PZT) ceramics is typically used for fabrications of such devices. In case of lanthaniun ion La3+ addition in PZT solid solution we can achieve piezoelectric ceramics with good transparency exhibiting both optical Pockels and Kerr

  15. Vanadium doping effects on microstructure and dielectric properties of barium titanate ceramics

    Microsoft Academic Search

    Wei Cai; Chunlin Fu; Zebin Lin; Xiaoling Deng

    2011-01-01

    V-doped barium titante ceramics were prepared by conventional solid state reaction method. XRD patterns show that V5+ ions have entered into the tetragonal perovskite structure of solid solution to substitute for Ti4+ ions on the B sites. Addition of vanadium accelerates grain growth of BTO ceramics and there is abnormal grain growth of barium titanate ceramics with higher vanadium concentration.

  16. Measurement of Micro Vibration of Car by Piezoelectric Ceramics

    NASA Astrophysics Data System (ADS)

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

    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.

  17. Micro-motion exposure method based on PZT piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Sun, Wenjun; Zhang, Mei-heng; Meng, Zhong

    2009-07-01

    There mainly is laser digital photofinishing technique and digital photofinishing technique based on LCD consisting of TFT and LCOS in the digital photofinishing field at the present time. The former have a good many merit such as wide color gamut, high processing rate, large output size and high brightness, but his cost is very high, his maintain technique being comparatively complex, that result in difficult use for people. The utilization ratio of the latter is low because of lower resolution and lower aperture ratio for LCD, but the digital photofinishing based on LCD have lower cost and higher utilization ration, being suitable for people's current standard of living. Considering above mentioned problem, a micro-motion exposure method based on PZT piezoelectric ceramics used in digital image photofinishing is presented. The two-dimension micro-motion exposure system consisting of PZT piezoelectric ceramics, LCD panel, polarizing film and spring strip is designed. By means of PZT piezoelectric ceramics the LCD panel is removed about the one half of the pixel size of the LCD panel for four times from the original place, at the same time imaging system is exposed four times at the printing paper. The software is used to control the time synchronization, the exposure time and motion range of the LCD panel. The system has advantages such as shorter response time than 0.1seconds, lesser motion error than 0.01 microns, high stability and repeatability. Experimental results show that the proposed micro-motion exposure method improve the picture brightness and enlarge output size, at the meantime reducing the cost of the system.

  18. OPTICAL AND PIEZOELECTRIC PROPERTIES OF TRANSPARENT PZN-PLZT CERAMICS

    Microsoft Academic Search

    GUOCHU DENG; AILI DING; XIA ZENG; TAO LIU; XINSEN ZHENG

    2006-01-01

    0.3Pb(Zn1\\/3Nb2\\/3)O3-0.7Pb0.96La0.4(ZrxTi1?x)O3(PZN-PLZT, x = 0.5?0.53) transparent piezoelectric ceramics with high density and pure perovskite have been synthesized by a two-stage hot-pressing procedure. The bulk densities of the specimens were measured by Archimedes method, and they are very close (> 99%) to the theoretical density. With the Zr\\/Ti ratios varying from 50\\/50 to 53\\/47, the d33 and kp show an ascending and

  19. Microstructure, electrical conductivity, and piezoelectric properties of bismuth titanate

    Microsoft Academic Search

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

    1996-01-01

    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

  20. Electrical properties of lanthanum doped barium titanate ceramics

    SciTech Connect

    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

    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.

  1. Microwave Dielectric Properties of Ceramic and Nanocomposite Titanates of Transition Metal

    NASA Astrophysics Data System (ADS)

    Rinkevich, Anatoly B.; Kuznetsov, Evgeny A.; Perov, Dmitry V.; Ryabkov, Yury I.; Samoylovich, Mikhail I.; Klescheva, Svetlana M.

    2014-10-01

    Ceramic and nanocomosite samples of the titanates of transition metals have been synthesized and their microwave dielectric properties have been investigated. Frequency and magnetic field dependences of the transmission and reflection coefficients in centimeter and millimeter wavebands were measured. It is established for most of studied ceramic titanates that transmission coefficient increases and reflection coefficient decreases when frequency increases. An absorption maximum has been found for ceramic sample made of Co0.9Fe0.1TiO3. The real and imaginary parts of complex dielectric permittivity were determined from measurements of transmission and reflection coefficients. On the whole, real part of dielectric permittivity of nanocomposite titanates based on an opal matrix is less than for ceramic titanates.

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

    SciTech Connect

    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

    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.

  3. Electrical properties of niobium doped barium bismuth-titanate ceramics

    SciTech Connect

    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

    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.

  4. Porosity Dependence of Piezoelectric Properties for Porous Potassium Niobate System Ceramics

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    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.

  6. A study of piezoelectric properties of (Ba0.85Ca0.15)(Zr0.9Ti0.1)O3 ceramics synthesized by sol-gel process

    NASA Astrophysics Data System (ADS)

    Praveen, J. Paul; Kumar, Kranti; James Raju, C. K.; Das, Dibakar

    2013-06-01

    Lead free piezoelectric ceramics 'Barium calcium zirconium titanate (Ba0.85Ca0.15)(Zr0.9Ti0.1)O3 have been prepared by sol-gel synthesis method. The structure and piezoelectric properties were investigated for the given BCZT system. X-ray diffraction (XRD) and transmission electron microscope (TEM) studies confirmed the formation of single phase BCZT nanoparticles (<50nm). The calcined and compacted powders sintered at 1550°C resulted in a complete perovskite structure. BCZT sample showed a high remnant polarization of 11.55 ?C/cm2 and a low coercive field (Ec) of 0.166 kV/cm. A high piezoelectric co-efficient of d33˜490 pC/N was obtained for the electrically poled sample. The study of microstructure on its piezoelectric properties of BCZT ceramics is discussed in this paper.

  7. Electron Emission from Lead-Zirconate-Titanate Ferroelectric Ceramic Induced by Pulse Electric Field

    Microsoft Academic Search

    Masanori Okuyama; Jun-ichi Asano; Yoshihiro Hamakawa

    1994-01-01

    Electron emission into vacuum from a thin plate of lead-zirconate-titanate (PZT) ferroelectric ceramics has been observed under the impression of pulse electric field. Electrons are emitted not only from the ceramic surface near the electrode edge but also through the thin metal electrode. The emitted charge per one pulse little depends on pulse frequency when it is less than 2

  8. Piezoelectric, pyroelectric and dielectric properties of La and Sm-doped PZT ceramics

    Microsoft Academic Search

    C. Pramila; T. C. Goel; P. K. C. Pillai

    1993-01-01

    Pair-doped lead zirconate titanate (PZT) samples were prepared by introducing lanthanum (La) and samarium (Sm) into the PZT lattice. Three compositions of pair-doped PZT were prepared by a conventional method. The dielectric, piezoelectric and pyroelectric properties of these samples were studied and compared with that of PLZT(8\\/65\\/35) samples prepared under the same conditions. The piezoelectric and pyroelectric figures of merit

  9. Processing of Fine-Scale Piezoelectric Ceramic/Polymer Composites for Sensors and Actuators

    NASA Technical Reports Server (NTRS)

    Janas, V. F.; Safari, A.

    1996-01-01

    The objective of the research effort at Rutgers is the development of lead zirconate titanate (PZT) ceramic/polymer composites with different designs for transducer applications including hydrophones, biomedical imaging, non-destructive testing, and air imaging. In this review, methods for processing both large area and multifunctional ceramic/polymer composites for acoustic transducers were discussed.

  10. Electromechanical coupling and temperature-dependent polarization reversal in piezoelectric ceramics.

    PubMed

    Weaver, Paul M; Cain, Markys G; Correia, Tatiana M; Stewart, Mark

    2011-09-01

    Electrostriction plays a central role in describing the electromechanical properties of ferroelectric materials, including widely used piezoelectric ceramics. The piezoelectric properties are closely related to the underlying electrostriction. Small-field piezoelectric properties can be described as electrostriction offset by the remanent polarization which characterizes the ferroelectric state. Indeed, even large-field piezoelectric effects are accurately accounted for by quadratic electrostriction. However, the electromechanical properties deviate from this simple electrostrictive description at electric fields near the coercive field. This is particularly important for actuator applications, for which very high electromechanical coupling can be obtained in this region. This paper presents the results of an experimental study of electromechanical coupling in piezoelectric ceramics at electric field strengths close to the coercive field, and the effects of temperature on electromechanical processes during polarization reversal. The roles of intrinsic ferroelectric strain coupling and extrinsic domain processes and their temperature dependence in determining the electromechanical response are discussed. PMID:21937304

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

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

    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.

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

    SciTech Connect

    Ducharme, S.; Feinberg, J.; Neurgaonkar, R.R.

    1987-12-01

    The authors measured the low-frequency (''unclamped'') electrooptic and piezoelectric coefficients in undoped BaTiO/sub 3/ and Sr/sub x/Ba/sub 1-x/Nb/sub 2/O/sub 6/ (chi - 0.61) crystals using interferometric techniques. The contribution of the piezoelectric effect to the Pockels measurement is discussed. For an applied ac electric field in the range 0.1-200 V/cm, the electrooptic and piezoelectric effects are linear in the magnitude of of the applied field and independent of its frequency in the range of 10 Hz-100 kHz. The unclamped electrooptic coefficients of poled BaTiO/sub 3/ single crystals are r/sub 13/ = 19.5 +- 1 pm/V and r/sub 33/ = 97 +- 7 pm/V, and for strontium barium niobate are r/sub 13/ = 47 +- 5 pm/V and r/sub 33/ = 235 +- 21 pm/V, all measured at a wavelength of 514.5 nm and at T = 23/sup 0/C. For the barium titanate samples the measured Pockels coefficient r/sub c/ identical to r/sub 33/ - (n/sub 1//n/sub 3/)/sup 3/r/sub 13/ = 79 +- 6 pm/V in good agreement with the value r/sub c/ = 76 +- 7 pm/V computed from the above values of r/sub 13/ and r/sub 33/, where n/sub 1/ and n/sub 3/ are the ordinary and extraordinary indexes of refraction, respectively. The measured piezoelectric coefficient is d/sub 23/ = +28.7 +- 2 pm/V for barium titanate, and is d/sub 23/ = +24.6 +- 2 pm/V for strontium barium niobate. They also measured the photoreflective coupling of two optical beams in the crystals, and they show that the dependence of the coupling strength on beam polarization is in fair agreement with the measured values of the Pockels coefficients.

  13. Lead-Free Piezoelectric Ceramics of (Bi1\\/2Na1\\/2)TiO3 KNbO3 1\\/2(Bi2O3·Sc2O3) System

    Microsoft Academic Search

    Hajime Nagata; Tadashi Takenaka

    1998-01-01

    Bismuth sodium titanate, (Bi1\\/2Na1\\/2)TiO3 (BNT)-based solid solution, a(Bi1\\/2Na1\\/2)TiO3 bKNbO3 c1\\/2(Bi2O3·Sc2O3) (a+b+c=1), [KTNS(100a\\/100b\\/100c)], was studied for its dielectric, ferroelectric and piezoelectric properties, as a new group of lead-free piezoelectric ceramics. Electrical measurements such as dielectric and piezoelectric properties show that the KTNS(100a\\/100b\\/100c) ceramics near the BNT side have a relatively high electromechanical coupling factor, k33 (=0.47). On particular, the amount of

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

    NASA Astrophysics Data System (ADS)

    Dong, Biqin

    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.

  15. Piezoelectric and dielectric performance of poled lead zirconate titanate subjected to electric cyclic fatigue

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Matsunaga, Tadashi; Lin, Hua-Tay; Mottern, Alexander M.

    2012-02-01

    Poled lead zirconate titanate (PZT) material as a single-layer plate was tested using a piezodilatometer under electric cyclic loading in both unipolar and bipolar modes. Its responses were evaluated using unipolar and bipolar measurements on the same setup. The mechanical strain and charge density loops exhibited various variations when the material was cycled for more than 108 cycles. The various quantities including loop amplitude, hysteresis, switchable polarization, and coercive field were characterized accordingly under the corresponding measurement conditions. At the same time, the 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 conditions also. Finally, the piezoelectric and dielectric coefficients were analyzed and their implications for the application of interest have been discussed.

  16. Field forced antiferroelectric-to-ferroelectric switching in modified lead zirconate titanate stannate ceramics

    Microsoft Academic Search

    Wuyi Pan; Qiming Zhang; Amar Bhalla; Leslie E. Cross

    1989-01-01

    Electric-field-forced antiferroelectric- to-ferroelectric phase transitions in several compositions of modified lead zirconate titanate stannate antiferroelectric ceramics are studied for ultra-high-field-induced strain actuator applications. Two types of fatigue effects are observed in these ceramic compositions. In one, the fatigue effects only proceed to a limited extent and the properties may be restored by annealing above the Curie temperature, while in the

  17. Photostrictive effect in lanthanum-modified lead zirconate titanate ceramics near the morphotropic phase boundary

    Microsoft Academic Search

    Patcharin Poosanaas; Kenji Uchino

    1999-01-01

    Photostrictive effect in lanthanum-modified lead zirconate titanate (PLZT) ceramics, one of the promising candidates for photostrictive materials, has been investigated with different contents of La and the ratio of Zr\\/Ti near the morphotropic phase boundary compositions. The maximum photocurrent and photovoltage were obtained at different compositions of PLZT ceramics: maximum photocurrent at 4\\/48\\/52, maximum photovoltage at 5\\/54\\/46. New figures of

  18. Electric fracture and polarization switching properties of piezoelectric ceramic PZT studied by the modified small punch test

    Microsoft Academic Search

    Y. Shindo; F. Narita; K. Horiguchi; Y. Magara; M. Yoshida

    2003-01-01

    The fracture behavior of a piezoelectric ceramic under applied electric fields has been discussed through experimental and theoretical characterizations. The modified small punch (MSP) tests were performed on a commercial piezoelectric ceramic. The fracture initiation loads under different electric fields were obtained from the experiment. Fracture surface was examined for the MSP specimens to identify the failure mechanisms under high

  19. Piezoelectric properties of polymer-piezoelectric ceramic composites crystallized under the action of an electric-discharge plasma

    NASA Astrophysics Data System (ADS)

    Kurbanov, M. A.; Sultanakhmedova, I. S.; Geidarov, G. M.; Aliev, G. G.

    2009-07-01

    The crystallization of a polymer-piezoelectric ceramic composite under the action of electric-discharge temperature and plasma is shown to cause strong oxidation of polymer chains, which increases the concentration of charge localization centers or the number of local levels in the quasi-bandgap of the polymer phase in the composite. In turn, this oxidation is accompanied by an increase in the interphase charges during electrothermal polarization, which favor effective polarization of piezophase domains and, hence, an increase in the piezoelectric properties. The degree of oxidation of the polymer phase is found to be controlled by the nature of the electric discharges used for composite crystallization. It is experimentally shown that piezoelectric composites should be crystallized under the action of a microdischarge that does not reach the streamer phase of its development. The optimum crystallization conditions are determined.

  20. Vibration Characteristics of Piezoelectric Lead Zirconate Titanate by Fluid Flow in Intravascular Oxygenator

    NASA Astrophysics Data System (ADS)

    Kim, Gi?Beum; Hong, Chul?Un; Kwon, Tae?Kyu

    2006-04-01

    In this paper, we describe the enhancement in oxygen transfer rate in hollow-fiber-membrane (HFM) modules using a plumbum piezoelectric lead zirconate titanate (PZT) actuator and a piezoelectric poly vinylidene fluoride (PVDF) sensor. We developed a vibrating intravascular lung assist device (VIVLAD) for patients having chronic respiratory problems and performed experiments on hydrodynamic flow through a bundle of sinusoidal vibrating hollow fibers. These modules were used to provide some insight into how wall vibrations might enhance the performance of an intravascular lung assist device. The experimental design and procedure are then applied to the fabrication of a device used to assess the effectiveness of membrane vibrations. The test section was a cylindrical duct with an inner diameter of 30 mm. The flow rate was controlled by a pump and monitored by a built-in flowmeter. The vibration apparatus was composed of a piezovibrator, a function generator, and a power amplifier. The direction of vibration was radial to the fluid flow. Gas flow rates of up to 6 L/min through 120-cm-long hollow fibers were achieved by exciting the piezovibrator. The time and frequency responses of PVDF sensors were investigated through various frequencies in VIVLAD. In these devices, the flow of blood and the source of oxygen were separated by a semipermeable membrane that allows oxygen and carbon dioxide to diffuse into and out of the fluid, respectively. Results of the experiments have shown that a vibrating intravascular lung assist device performs effectively.

  1. The development of lead zirconate titanate thin films for piezoelectric microactuators

    NASA Astrophysics Data System (ADS)

    Nickles, Annabel Susan

    Piezoelectric actuation of a thin film is one means used for electrical-mechanical transduction in Microelectromechanical systems (MEMS). Currently, the most commonly employed piezoelectric thin-film material is ZnO. Replacing ZnO with certain compositions of lead zirconate titanate (PZT) should improve the performance of many MEMS devices due to the significantly greater piezoelectric coefficients of PZT (˜20 times greater than ZnO). In this dissertation I investigate the growth and properties---particularly piezoelectric properties---of PZT thin films. I also fabricate a PZT-based MEMS structure, a flexural plate wave (FPW) pump, and compare its performance with similar ZnO-based devices. PZT films of two compositions, Pb(Zr0.7Ti0.3)O 3 and Pb(Zr0.5Ti0.5)O3, were grown using reactive, multi-target, RF-magnetron sputtering on Pt-coated silicon wafers. Films were deposited at temperatures from 200°C to 400°C and rapid thermally annealed between 450°C and 700°C to crystallize perovskite PZT. The effects of as-deposited lead excess and deficiency on perovskite phase formation and film properties were studied. Films of composition Pb(Zr 0.5Ti0.5)O3, with relative dielectric constants of 1000, remanent polarizations of 20°C/cm2, coercive fields of 60 kV/cm, and effective piezoelectric d33 coefficients of 50 pm/V were obtained. These films show promise for use in MEMS. PZT films also were grown on a series of substrates using pulsed laser deposition (PLD). Epitaxial (100) films were obtained on LaAlO3 single crystal substrates, and randomly oriented films were obtained on Pt-coated silicon wafers. A conducting oxide electrode, (La0.5Sr0.5 )CoO3, was used for these films. Good structural and ferroelectric properties were obtained, however these films have limitations for use in MEMS. An FPW pump was fabricated using a sol-gel PZT thin film. Measured wave amplitudes were significantly higher than those of a similar ZnO-based device at the same driving voltage---250 A on a 5-finger pair PZT device as compared to 145 A on a 25-finger pair ZnO device. Estimations of pumping speed indicate that the PZT device should have a pumping speed more than an order of magnitude greater than the ZnO device.

  2. Low-cost and easy experiment to study the electromechanical resonance of piezoelectric ceramics

    Microsoft Academic Search

    A. Santana-Gil; A. Pela´iz-Barranco; L. Rodri´guez-Lo´pez

    2005-01-01

    An easy and low-cost experiment is presented to characterize the electromechanical resonance of piezoelectric ceramics. By using virtual instrumentation two instruments are substituted simultaneously: an oscilloscope and a frequency-meter. This is accomplished by using a personal computer, a data acquisition card and LabVIEW as programming environment. The experiment has been developed as a contribution to improve the researchers on piezoelectric

  3. Piezoelectric properties of polymer-piezoelectric ceramic composites crystallized under the action of an electric-discharge plasma

    Microsoft Academic Search

    M. A. Kurbanov; I. S. Sultanakhmedova; G. M. Geidarov; G. G. Aliev

    2009-01-01

    The crystallization of a polymer-piezoelectric ceramic composite under the action of electric-discharge temperature and plasma\\u000a is shown to cause strong oxidation of polymer chains, which increases the concentration of charge localization centers or\\u000a the number of local levels in the quasi-bandgap of the polymer phase in the composite. In turn, this oxidation is accompanied\\u000a by an increase in the interphase

  4. Piezoelectric properties of polymer-piezoelectric ceramic composites crystallized under the action of an electric-discharge plasma

    Microsoft Academic Search

    M. A. Kurbanov; I. S. Sultanakhmedova; G. M. Geidarov; G. G. Aliev

    2009-01-01

    The crystallization of a polymer-piezoelectric ceramic composite under the action of electric-discharge temperature and plasma is shown to cause strong oxidation of polymer chains, which increases the concentration of charge localization centers or the number of local levels in the quasi-bandgap of the polymer phase in the composite. In turn, this oxidation is accompanied by an increase in the interphase

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

    PubMed

    Jing, Yang; Luo, Jianbin; Yang, Wenyan; Ju, Guoxian

    2004-11-01

    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 practical application to the drive products. The U-type substrate attached to each side via piezoelectric elements also was simulated by the finite-element method and practically measured by a laser Doppler vibrometer in order to testify the driving mechanics of it. The micro-actuator coupled with two piezoelectric elements featured large displacement of 0.875 microm and high-resonance frequency over 22 kHz. The novel piezoelectric micro-actuators then possess a useful compromise performance to displacement, resonance frequency, and generative force. The results reveal that the new design concept provides a valuable alternative for multilayer piezoelectric micro-actuators. PMID:15600092

  6. A three-phase magnetoelectric composite of piezoelectric ceramics, rare-earth iron alloys, and polymer

    Microsoft Academic Search

    C.-W. Nan; L. Liu; N. Cai; J. Zhai; Y. Ye; Y. H. Lin; L. J. Dong; C. X. Xiong

    2002-01-01

    A class of multiferroic, three-phase particulate composites of Tb-Dy-Fe alloy, lead-zirconate-titanate (PZT), and polymer are investigated, in which a small volume fraction f of Tb-Dy-Fe alloy particles are dispersed in a PZT\\/polymer mixture. The measured dielectric, piezoelectric, and magnetoelectric properties demonstrate that a percolation transition occurs at f~0.12 in the composites. When f is low (e.g., f<0.07), the composites exhibit

  7. Preisach modeling of piezoelectric nonlinearity in ferroelectric ceramics

    Microsoft Academic Search

    G. Robert; D. Damjanovic; N. Setter; A. V. Turik

    2001-01-01

    Piezoelectric response nonlinearity is approached using the Preisach description of hysteretic systems as collection of distributed bistable units. The Preisach model and its recent physical interpretation in terms of moving domain wall in a stochastically described pinning field are reviewed. It is shown that such an approach can effectively render not only the piezoelectric coefficient field dependences but also the

  8. Aurivillius ceramics: Bi4Ti3O12-based piezoelectrics

    Microsoft Academic Search

    T. JARDIEL; A. C. CABALLERO; M. VILLEGAS

    2008-01-01

    Aurivillius oxides family has attracted great interest in the last years due to their promising electrical properties as high tem- perature piezoelectric materials. Piezoelectric materials that could operate in extreme conditions of use (elevated temperatures and hostile environments) could be of particular interest for different technological applications. Furthermore, increasing con- cerns for environmental issues have promoted the study of new

  9. C-Mode Ultrasonic System Based in Piezoelectric Ceramics and PVDF Polymers for Several Acoustic Impedances

    Microsoft Academic Search

    L. Rivera Galván; R. Rodríguez Ruiz; E. Suaste Gómez

    2006-01-01

    The present paper provides a basic ultrasonic system based in a C-mode using a piezoelectric ceramic as a transmitter and a PVDF polymer as receiver and its behavior in several acoustic impedances in order to establish this system as a novel way for ultrasonic applications. This paper provides experimental results about how is the ultrasonic signal affected in several acoustic

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

    SciTech Connect

    Koval, V.; Reece, M.J.; Bushby, A.J. [Department of Materials, Queen Mary University of London, Mile End Road, London, E1 4NS (United Kingdom)

    2005-04-01

    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 {mu}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 d{sub eff} of about 35% of its initial value for the thin films at a maximum force of 500 mN.

  11. Transverse piezoelectric coefficient measurement of flexible lead zirconate titanate thin films

    NASA Astrophysics Data System (ADS)

    Dufay, T.; Guiffard, B.; Thomas, J.-C.; Seveno, R.

    2015-05-01

    Highly flexible lead zirconate titanate, Pb(Zr,Ti)O3 (PZT), thin films have been realized by modified sol-gel process. The transverse piezoelectric coefficient d31 was determined from the tip displacement of bending-mode actuators made of PZT cantilever deposited onto bare or RuO2 coated aluminium substrate (16 ?m thick). The influence of the thickness of ruthenium dioxide RuO2 and PZT layers was investigated for Pb(Zr0.57Ti0.43)O3. The modification of Zr/Ti ratio from 40/60 to 60/40 was done for 3 ?m thick PZT thin films onto aluminium (Al) and Al/RuO2 substrates. A laser vibrometer was used to measure the beam displacement under controlled electric field. The experimental results were fitted in order to find the piezoelectric coefficient. Very large tip deflections of about 1 mm under low voltage (˜8 V) were measured for every cantilevers at the resonance frequency (˜180 Hz). For a given Zr/Ti ratio of 58/42, it was found that the addition of a 40 nm thick RuO2 interfacial layer between the aluminium substrate and the PZT layer induces a remarkable increase of the d31 coefficient by a factor of 2.7, thus corresponding to a maximal d31 value of 33 pC/N. These results make the recently developed PZT/Al thin films very attractive for both low frequency bending mode actuating applications and vibrating energy harvesting.

  12. The investigation of depoling mechanism of densified KNbO{sub 3} piezoelectric ceramic

    SciTech Connect

    Ge Haiyan; Hou Yudong; Rao Xue; Zhu Mankang; Wang Hao; Yan Hui [Department of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China)

    2011-07-18

    Thermal depoling phenomena determine the upper temperature limit of the piezoelectric ceramics in application. In this paper, high-densified KNbO{sub 3} ceramics derived from single-crystalline nanostructures exhibited favorable piezoelectric constants d{sub 33}, which varied from 105 to 80 pC/N over a broad temperature range from 25 to 225 deg. C. In situ x-ray diffraction combined with Raman spectra demonstrate clearly the transition sequence of crystallographic orientations during thermal depoling process. The interaction between defect dipoles D and spontaneous polarization inside domains P{sub s} favored to preserve piezoelectric activity, while the spontaneous rotation of P{sub s} induced by the phase transition resulted in the deliquesce of d{sub 33}.

  13. Piezoelectric/photoluminescence effects in rare-earth doped lead-free ceramics

    NASA Astrophysics Data System (ADS)

    Yao, Qirong; Wang, Feifei; Jin, Chengchao; Tang, Yanxue; Wang, Tao; Shi, Wangzhou

    2013-10-01

    In the present work, we report the environmentally-friendly multifunctional effects—piezoelectric/photoluminescence effects, which originated from the combination of the electromechanical properties and the photoluminescence effect through introducing the rare-earth elements (Pr and Eu) into the (Bi0.5Na0.5)TiO3-BaTiO3 ceramics with the composition around the morphotropic phase boundary. Compared to the pure piezoelectric ceramic, the proposed system simultaneously exhibited enhanced ferroelectric, piezoelectric, dielectric properties along with strong photoluminescence effects, which exhibited potential applications in sensor, and electro-mechano-optical integration. In addition, the present work also provides a promising path for us to fabricate multifunctional composites.

  14. Recent developments in piezoelectric and electrostrictive sensors and actuators for smart structures

    Microsoft Academic Search

    L. Eric Cross

    1993-01-01

    Piezoelectricity will be defined phenomenologically and discussed pictorially to underscore the distinction between single crystal piezoelectrics and the poled ceramics which form the basis for most practical sensor and actuator systems. The classical lead zirconate: lead titanate (PZT) family is the most widely used. Recent advances in the understanding of the conventional morphotropic phase boundary (MPB) compositions are discussed with

  15. Field forced antiferroelectric-to-ferroelectric switching in modified lead zirconate titanate stannate ceramics

    SciTech Connect

    Pan, W.; Zhang, Q.; Bhalla, A.; Cross, L.E. (Materials Research Lab., Pennsylvania State Univ., University Park, PA (US))

    1989-04-01

    Electric-field-forced antiferroelectric- to-ferroelectric phase transitions in several compositions of modified lead zirconate titanate stannate antiferroelectric ceramics are studied for ultra-high-field-induced strain actuator applications. Two types of fatigue effects are observed in these ceramic compositions. In one, the fatigue effects only proceed to a limited extent and the properties may be restored by annealing above the Curie temperature, while in the other, the fatigue effects proceed to a large extent and the properties cannot be restored completely by heat treatment.

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

    Microsoft Academic Search

    Guntis Liberts; Girts Ivanovs; Vilnis Dimza; Edmunds Tamanis

    2005-01-01

    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

  17. Densification and microstructure of lead zirconate titanate ceramics fabricated from a triol sol–gel powder

    Microsoft Academic Search

    C. Sangsubun; A. Watcharapasorn; S. Jiansirisomboon

    2008-01-01

    Lead zirconate titanate (PZT) nano-powder was prepared by a triol sol–gel process. X-ray diffraction and transmission electron microscopy results showed that as-synthesized amorphous powder started to crystallize at the calcination temperature above 500°C. The crystalline powder was formed into pellets and sintered at temperatures between 900 and 1300°C. Co-existence of tetragonal and rhombohedral phase was observed in all ceramics. Microstructural

  18. Analysis of nonisothermal sintering of zinc-titanate ceramics doped with MgO

    Microsoft Academic Search

    N. Obradovic; S. Stevanovic; M. M. Ristic

    2008-01-01

    The aim of this work is to analyze nonisothermal sintering of zinc titanate ceramics doped with MgO obtained by mechanical\\u000a activation. Mixtures of ZnO, TiO2, and MgO (0, 1.25, and 2.5%) are mechanically activated for 15 min in a planetary ball mill. Nonisothermal sintering is performed\\u000a in air for 120 min at 800, 900, 1000, and 1100 °C. Microstructure parameters

  19. Specific features of switching processes in soft ferroelectric ceramics based on lead zirconate-titanate

    NASA Astrophysics Data System (ADS)

    Akbaeva, G. M.; Borodin, V. Z.

    2015-03-01

    Switching processes in soft ferroelectric ceramic materials based on lead zirconate-titanate have been studied. It has been found that these materials, which possess properties of relaxors and have an additional low-frequency phase transition between two rhombohedral phases, R3 c ? R3 m, exhibit specific features upon the repolarization near this transition: in addition to the decrease in the coercive field, the domain compression effect disappears, which indicates changes in the switching mechanism.

  20. Barium titanate glass–ceramic thin films for integrated high-dielectric media

    Microsoft Academic Search

    Kui Yao; Weiguang Zhu

    2002-01-01

    Ba?Ti?B glass–ceramic thin films with a substantial number of perovskite barium titanate (BaTiO3) grains were deposited on Pt-coated silicon substrates by sol–gel processing. The prepared films exhibited a mixed structure of glass phase and BaTiO3 grains tens of nanometers in diameter. A self-mending phenomenon for microcracks was observed in the films. Electrical characterisation results showed a high dielectric constant, low

  1. Microstructural Evolution under Polarization Switching of Ferroelectric Tin-modified Lead Zirconate Titanate Ceramics

    Microsoft Academic Search

    Yung-Fu Tsun; Chen-Chia Chou

    1999-01-01

    Electric fatigue properties of ferroelectric niobium-doped tin-modified lead zirconate titanate (PNZST) ceramics were investigated using polarization-electric field (P E) measurements, and the corresponding microstructure evolution was studied employing transmission electron microscopy. The results show that domain boundaries are induced under repeated electric field application, and the microstructures become more complicated due to domain intersection. The mobility of domain boundaries degrades

  2. Characterization of lead zirconate titanate ceramics for use in miniature high-frequency (20-80 MHz) transducers

    Microsoft Academic Search

    F. Stuart Foster; Linda K. Ryan; Daniel H. Turnbull

    1991-01-01

    The material properties of lead zirconate titanate (PZT) ceramics for operation in the thickness mode at frequencies as high as 80 MHz are reported. Each of the ceramics tested showed a reduction in k t with increasing frequency. In a fine-grained PZT, values of kt as high as 0.44 were measured at 80 MHz. The effects of grain size were

  3. A comparison of single crystal versus ceramic piezoelectric materials for acoustic applications

    NASA Astrophysics Data System (ADS)

    Tressler, James F.

    2003-04-01

    For nearly fifty years, piezoelectric ceramics (primarily from the PZT family) have been the materials of choice as the active elements in sound projectors and receivers, medical ultrasound probes, etc. There is currently great interest in the materials community in the use of newly discovered single crystal relaxor ferroelectric materials as a replacement in applications that currently utilize piezoelectric ceramics. The salient features of single crystal piezoelectrics are strains an order of magnitude larger than are achievable in PZT and electromechanical coupling coefficients on the order of 90 percent. This presentation will provide a more thorough comparison of the physical and piezoelectric properties of single crystal piezoelectrics versus conventional PZT piezoceramics. This will hopefully provide the transducer designer with a better understanding of the pros and cons in the use of single crystals. In addition, a brief review of single crystal synthesis procedures will be described. Finally, some acoustic devices utilizing both single crystals and piezoceramics will be compared. [Work supported by DARPA and ONR Code 321-TS.

  4. Novel methods of powder preparation and ceramic forming for improving reliability of multilayer ceramic actuators

    Microsoft Academic Search

    William J. Dawson; Scott L. Swartz; Jean P. Issartel

    1993-01-01

    Critical components of many smart systems employ multilayer piezoelectric actuators based on lead zirconate titanate (PZT) ceramics. Applications include active vibration systems, noise suppression, acoustic camouflage, actuated structures, reconfigurable surfaces, and structural health monitoring. Two strategies involving novel materials processing techniques are discussed for improving the performance and reliability of PZT ceramic components. The first is the use of an

  5. Effects of V 2 O 5 addition on the phase-structure and dielectric properties of zinc titanate ceramics

    Microsoft Academic Search

    Xiangchun Liu; Feng Gao; Lili Zhao; Ming Zhao; Changsheng Tian

    2007-01-01

    V2O5-doped zinc titanate ceramics (ZnTiO3) were prepared by conventional mixed-oxide method combined with a semi-chemical processing. The effects of V2O5 addition on the phase-structures and the dielectric properties of ZnTiO3 ceramics were investigated. The results show the sintering temperature of zinc titanate ceramics could be lowered from 1,150\\u000a to 930 °C by reducing the size of starting powders using a

  6. Investigation on dielectric and piezoelectric characterization of PLSZT-BT ceramics

    NASA Astrophysics Data System (ADS)

    Ramam, K.; Chandramouli, K.

    2008-06-01

    In this paper, the ceramic compositions (1-x)Pb{1-w-y}La{w}Sr{y}(Zr{z}Ti{1-z})(1-w/4)O{3}-xBaTiO{3}, where x = 0.15, 0.25, 0.35 and 0.45, fabricated through solid state reaction method were investigated for phase formation, microstructure, density, dielectric and piezoelectric properties. The combination of the two perovskite structured stoichiometric compositions (i.e., isovalent Sr2+ modified PLZT and BaTiO{3}) indicated that tetragonality enhanced further due to BaTiO{3} concentration in PLSZT lattice. The BaTiO{3} in PLSZT ceramics were homogeneously distributed within the two perovskite structured solid solutions. The dielectric characterization indicated that \\varepsilon RT enhanced while tan? RT and Tc decreased with increasing BT additions into PLSZT perovskite. The maximum \\varepsilon RT = 2986 and \\varepsilon T_c = 21468 were found in 0.55PLSZT-0.45BT ceramic system. The piezoelectric properties were influenced by both BaTiO{3} and Sr2+ modified PLZT perovskite. The influence of BT modified PLSZT ceramics showed significant variations that has been discussed. The piezoelectric properties remarkably enhanced with maximum (kp = 0.541 and d33 = 518 pC/N) values in the 0.55PLSZT-0.45BT composition and thus, could be a promising candidate among this series for possible capacitor, sensor and actuator applications.

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

    PubMed

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

    2013-05-14

    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

  8. Effect of compositional inhomogeneity on the structure and properties of lead zirconate titanate ferroelectric ceramics

    SciTech Connect

    Bogosova, Y.B.; Konstantinov, G.M. [Rostov State Univ. (Russian Federation)

    1995-04-01

    Lead zirconate titanate (PZT) ferroelectric ceramics are most generally produced from oxides by the solid-state-reaction method. The synthesis stage, as a rule, does not yield highly homogeneous solid solutions. Because of incomplete mixing of the starting reagents, the forming solid-solution material contains fairly large regions that differ in composition and, hence, in lattice parameters and physical properties. Homogenization of the solid solution is achieved at the sintering stage. Solid solutions whose compositions fall within morphotropic-transition regions (MTRs) are particularly sensitive to the preparation conditions used in producing ferroelectric ceramics because, for these solid solutions, even minor local changes in the concentration of components may have a considerable effect on phase composition, lattice parameters, and, hence, physical properties. The objective of this work was to study the effect of the homogeneity changes caused by sintering on the structure and properties of PZT ferroelectric ceramics.

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

    SciTech Connect

    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

    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.

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

    NASA Technical Reports Server (NTRS)

    Hooker, Matthew W.

    1998-01-01

    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.

  11. Modeling of high-temperature ferroelectric-piezoelectric ceramics

    SciTech Connect

    Reznichenko, L.A.; Dergunova, N.V.; Razumovskaya, O.N. [Rostov State Univ. (Russian Federation)] [and others

    1995-06-01

    A designed high-temperature materials based on PZT (PKR-26, t{sub w} = 300{degrees}C), tetragonal potassium tungsten bronze (PKR-45, t{sub w} = 350{degrees}C), bismuth perovskites (PKR-50, t{sub w} = 500{degrees}C), and lithium metaniobate (PKR-61, t{sub w} = 950{degrees}C). These materials are potential candidates for use in piezoelectric sensors for the automobile industry, aircraft construction, ship building, metallurgy, and geology.

  12. Piezoresistive ceramic sensor based on PTCR barium titanate

    SciTech Connect

    Capurso, J.S.; Schulze, W.A.; Alles, A.B. [Alfred Univ., NY (United States)

    1994-12-31

    High purity, chemically prepared barium titanate was doped with 0.3 atom% La and 0.04 atom% Mn by precipitation. Using standard techniques, tape-cast sheets of the PTCR composition as well as the base insulating powder were made. A three-layer sensor was laminated with the upper and lower PTCR layers separated by an insulating BaTiO{sub 3} layer. After binder burnout, the device was sintered at 1350{degrees}C in flowing N{sub 2} followed by cooling in flowing O{sub 2} at 300{degrees}C/hour. The sensor was loaded using a standard four-point bend test configuration. The change in resistivity with increasing load was observed to the linear, with positive and negative piezoresistive coefficients for the PTCR layers under compression and tension, respectively. These trends are in general agreement with the Heywang-Jonker model of grain boundary potential barriers.

  13. The Charge-Free Zone Model for Conductive Cracks in Dielectric and Piezoelectric Ceramics

    Microsoft Academic Search

    Tong-Yi Zhang

    In the charge-free zone (CFZ) model, dielectric and piezoelectric ceramics are treated to be mechanically brittle and electrically\\u000a ductile. For an electrically conductive crack under electrical and\\/or mechanical loading, various charge emission mechanisms\\u000a may function jointly at the tip due to the high electric field concentration. Charge emission and charge trapping consume\\u000a more work and thus lead to a high

  14. Processing and characterization of high Q m ferroelectric ceramics

    Microsoft Academic Search

    C Galassi; E Roncari; C Capiani; F Craciun

    1999-01-01

    Use of ferroelectric ceramics in applications like piezoelectric transformers was made possible by the development of new materials with high electromechanical coupling coefficients and high mechanical quality factor. “Hard’’ ferroelectric ceramics of complex composition based on lead zirconate titanate with Nb, Mg, Mn and Li additives have been prepared. The perovskitic phase was produced by solid phase reaction of the

  15. Photostriction of Sol–Gel Processed PLZT Ceramics

    Microsoft Academic Search

    A Dogan; A V Prasadarao; K Uchino; Patcharin Poosanaas; S Komarneni

    1997-01-01

    Lanthanum-modified lead zirconate titanate (PLZT) ceramic materials have gained considerable attention due to their photostriction, which is the superposition of photovoltaic and piezoelectric effects. However, the photovoltaic effect and the induced strain response are also influenced by the fabrication and processing conditions. The PLZT ceramics produced by conventional oxide mixing process exhibit moderate photostrictive properties due to the inhomogeneous distribution

  16. Lead lanthanum zirconate titanate ceramic thin films for energy storage.

    PubMed

    Tong, Sheng; Ma, Beihai; Narayanan, Manoj; Liu, Shanshan; Koritala, Rachel; Balachandran, Uthamalingam; Shi, Donglu

    2013-02-01

    An acetic-acid-based sol-gel method was used to deposit lead lanthanum zirconate titanate (PLZT, 8/52/48) thin films on either platinized silicon (Pt/Si) or nickel buffered by a lanthanum nickel oxide buffer layer (LNO/Ni). X-ray diffraction and scanning electron microscopy of the samples revealed that dense polycrystalline PLZT thin films formed without apparent defects or secondary phases. The dielectric breakdown strength was greater in PLZT thin films deposited on LNO/Ni compared with those on Pt/Si, leading to better energy storage. Finally, optimized dielectric properties were determined for a 3-?m-thick PLZT/LNO/Ni capacitor for energy storage purposes: DC dielectric breakdown strength of ?1.6 MV/cm (480 V), energy density of ?22 J/cc, energy storage efficiency of ?77%, and permittivity of ?1100. These values are very stable from room temperature to 150 °C, indicating that cost-effective, volumetrically efficient capacitors can be fabricated for high-power energy storage. PMID:23373765

  17. Electrical conductivity of the Bi-based lead-free piezoelectric ceramic BiFeO3

    Microsoft Academic Search

    Myong-Ho Kim

    2008-01-01

    Bi-based lead-free piezo-ceramics such as BiFeO3 (BFO) have been studied intensively in attempts to replace PZT-based ceramics. However, some of those ceramics have resistivity causing difficulties in poling thus yielding poor piezoelectric properties. To improve proper-ties, it is necessary to have better understanding on the conduction mechanism and defect chemistry of those systems. In this work, BNT as a base

  18. Two dielectric relaxation mechanisms observed in lanthanum doped barium strontium titanate glass ceramics

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Ma, Tao; Wang, Xiangrong; Yuan, Zongbao; Zhang, Qian

    2011-04-01

    The dielectric relaxation at temperatures ranging from 100 °C to 550 °C in lanthanum-doped barium strontium titanate glass ceramics has been investigated by measurements of both dielectric temperature curve and complex impedance spectroscopy. The temperature dependence of dielectric properties reveals two regimes. In the first regime, at temperatures lower than 350 °C, the charge carrier contributed to interfacial polarization is conduction electrons. In contrast, in the second regime, at temperatures higher than 350 °C, the dielectric relaxation was attributed to the thermally activated movement of oxygen vacancies. Thus, two relaxation mechanisms could be explained on the basis of defect chemistry and impedance analysis.

  19. Nanostructure Control of Barium Titanate-Potassium Niobate Nanocomplex Ceramics and Their Enhanced Ferroelectric Properties

    NASA Astrophysics Data System (ADS)

    Wada, Satoshi; Yamashita, Kenta; Fujii, Ichiro; Nakashima, Kouichi; Kumada, Nobuhiro; Moriyoshi, Chikako; Kuroiwa, Yoshihiro; Fujikawa, Yoshinori; Tanaka, Daisuke; Furukawa, Masahito

    2012-09-01

    Barium titanate (BaTiO3,BT)-potassium niobate (KNbO3,KN) nanocomplex ceramics with various KN/BT molar ratios were prepared by a solvothermal method. From a transmission electron microscopy (TEM) observation, it was confirmed that the KN layer thickness on BT particles was controlled from 5 to 40 nm by controlling KN/BT molar ratios. Their dielectric constants were measured at room temperature and 1 MHz, and the maximum dielectric constant of 370 was measured for the BT-KN nanocomplex ceramics with a KN thickness of 22 nm. TEM observation revealed that at a KN thickness below 22 nm, the BT/KN heteroepitaxial interface was assigned as a strained interface, while at 40 nm, the interface was assigned as a relaxed one. These results suggested that the strained heteroepitaxial interface could be responsible for the enhanced dielectric properties.

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

    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.

  1. Titanate ceramics for immobilisation of uranium-rich radioactive wastes arising from 99Mo production

    NASA Astrophysics Data System (ADS)

    Carter, M. L.; Li, H.; Zhang, Y.; Vance, E. R.; Mitchell, D. R. G.

    2009-02-01

    Uranium-rich liquid wastes arising from UO 2 targets which have been neutron-irradiated to generate medical radioisotopes such as 99mTc require immobilisation. A pyrochlore-rich hot isostatically pressed titanate ceramic can accommodate at least 40 wt% of such waste expressed on an oxide basis. In this paper, the baseline waste form composition (containing 40 wt% UO 2) was adjusted in two ways: (a) varying the UO 2 loading with constant precursor oxide materials, (b) varying the precursor composition with constant waste loading of UO 2. This resulted in the samples having a similar phase assemblage but the amounts of each phase varied. The oxidation states of U in selected samples were determined using diffuse reflection spectroscopy (DRS) and electron energy loss spectroscopy (EELS). Leaching studies showed that there was no significant difference in the normalised elemental release rates and the normalised release rates are comparable with those from synroc-C. This demonstrates that waste forms based on titanate ceramics are robust and flexible for the immobilisation of U-rich waste streams from radioisotope processing.

  2. Zirconium titanate ceramic pigments: Crystal structure, optical spectroscopy and technological properties

    SciTech Connect

    Dondi, M. [Institute of Science and Technology for Ceramics (ISTEC-CNR), Via Granarolo 64, 48018 Faenza (Italy); Matteucci, F. [Institute of Science and Technology for Ceramics (ISTEC-CNR), Via Granarolo 64, 48018 Faenza (Italy)]. E-mail: matteucci@istec.cnr.it; Cruciani, G. [Department of Earth Sciences, Via Saragat 1, University of Ferrara, 44100 Ferrara (Italy)

    2006-01-15

    Srilankite-type zirconium titanate, a promising structure for ceramic pigments, was synthesized at 1400 deg. C following three main doping strategies: (a) ZrTi{sub 1-x}A{sub x}O{sub 4} (b) ZrTi{sub 1-x-y}A{sub x}B{sub y}O{sub 4} and (c) Zr{sub 1-x}C{sub x}TiO{sub 4} where A=Co, Cr, Fe, Mn, Ni or V (chromophores), B=Sb or W (counterions) and C=Pr (chromophore); x=y=0.05. Powders were characterized by XRD with Rietveld refinements and DRS in the UV-visible-NIR range; technological properties were appraised in several ceramic matrices (frits, glazes and body). Zirconium titanate can be usefully coloured with first row transition elements, giving green and greenish yellow (Co and Ni); orange-buff (Cr and V); tan-brown hues (Mn and Fe). In industrial-like synthesis conditions, a disordered structure as (Zr,Ti)O{sub 2}, with both Zr and Ti randomly distributed in the octahedral site, is achieved. Doping with chromophores and counterions induces unit cell dimensions variation and causes an oversaturation in zirconium oxide. Optical spectroscopy reveals the occurrence of Co{sup 2+}, Cr{sup 3+}, Fe{sup 3+}, Mn{sup 2+}, Mn{sup 3+}, Ni{sup 2+}, V{sup 3+} and V{sup 4+}. The zirconium titanate pigments fulfil current technological requirements for low-temperature applications, but exhibit a limited chemico-physical stability for higher firing temperature and in chemically aggressive media.

  3. Defect properties of cobalt-doped hexagonal barium titanate ceramics.

    PubMed

    Langhammer, H T; Böttcher, R; Müller, T; Walther, T; Ebbinghaus, S G

    2015-07-29

    X-ray diffraction (XRD) patterns, electron paramagnetic resonance (EPR) powder spectra (9 and 34?GHz) and the magnetic susceptibility of BaTiO3 + 0.04 BaO + x/2 Co2O3 (0.001 ? x ? 0.02) ceramics were studied to investigate the incorporation of Co ions in the BaTiO3 lattice and their valence states as well as the development of the hexagonal phase (6H modification) in dependence on doping level x and sintering temperature Ts. At Ts = 1400?°C the 6H modification begins to occur at a nominal Co concentration x of about 0.001 and for x > 0.005 the samples are completely hexagonal at room temperature. Two different EPR spectra were observed in the 6H modification of BaTiO3, which were both assigned to paramagnetic Co(2+) ions located at the two crystallographically non-equivalent Ti sites in 6H-BaTiO3. The EPR g tensor values as well as the molar paramagnetic susceptibility, measured in the temperature range 5?K-300?K at a magnetic field of 9?T, were analyzed in the framework of the ligand field theory using the program CONCORD. The combination of EPR and magnetic measurements reveals that in air-sintered 6H BaTiO3, the incorporated Co occurs as a mixture of paramagnetic Co(2+) and diamagnetic Co(3+) ions, whereas in samples annealed in reducing atmosphere the majority of Co is in the divalent state. The occurrence of Co(4+) can be excluded for all investigated samples. The sample color caused by Co(2+) and Co(3+) ions is beige/light yellow and dark grey/black, respectively. The majority of the Co(2+) ions substitutes Ti in the exclusively corner-sharing oxygen octahedra possessing nearly cubic symmetry. The corresponding ligand field parameter [Formula: see text] amounts to about -28?000?cm(-1) (Wybourne notation, 10Dq ? 20?000?cm(-1)). In the reduced samples nearly 5% of the detected Co(2+) ions occupy the Ti site in the face-sharing oxygen octahedra, which are significantly trigonally distorted. The negative sign of the obtained ligand field parameter [Formula: see text] ? -7300?cm(-1) reflects a compression of this octahedron in direction of the hexagonal c-axis. PMID:26154400

  4. High-Power Piezoelectric Characteristics of Nontextured Bismuth Layer-Structured Ferroelectric Ceramics

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

    High-power piezoelectric characteristics under continuous driving were studied on some bismuth layer-structured ferroelectric ceramics, i.e., Sr0.25Bi2.75Ti0.75Ta1.25O9 (SBTT, m = 2), Bi4Ti2.98V0.02O12 (BITV, m = 3), Bi4Ti3O12-SrBi4Ti4O15 + MnCO3 0.2 wt % (BIT-SBTi, m = 3, 4), and (Sr0.7Ca0.3)2Bi4Ti5O18 + MnCO3 0.2 wt % (SCBT, m = 5). The vibration velocities, v0-p, of SBTT, BIT-SBTi, and SCBT ceramics were above 2.0 m/s at 5 V/mm. Also, we observed that the resonance frequency changes and temperatures on the sample surfaces for SBTT, BIT-SBTi, and SCBT ceramics were less than 1.0% and 50 °C at a v0-p of 2.0 m/s, respectively. The high-power characteristics of the ceramics were superior to those of BITV and hard Pb(Zr,Ti)O3 (abbreviated as PZT) at a vibration velocity v0-p > 0.6 m/s. Therefore, SBTT, BIT-SBTi and SCBT ceramics are promising candidates for lead-free high-power applications requiring high vibration velocity and frequency stability.

  5. Piezoelectric ceramic (PZT) modulates axonal guidance growth of rat cortical neurons via RhoA, Rac1, and Cdc42 pathways.

    PubMed

    Wen, Jianqiang; Liu, Meili

    2014-03-01

    Electrical stimulation is critical for axonal connection, which can stimulate axonal migration and deformation to promote axonal growth in the nervous system. Netrin-1, an axonal guidance cue, can also promote axonal guidance growth, but the molecular mechanism of axonal guidance growth under indirect electric stimulation is still unknown. We investigated the molecular mechanism of axonal guidance growth under piezoelectric ceramic lead zirconate titanate (PZT) stimulation in the primary cultured cortical neurons. PZT induced marked axonal elongation. Moreover, PZT activated the excitatory postsynaptic currents (EPSCs) by increasing the frequency and amplitude of EPSCs of the cortical neurons in patch clamp assay. PZT downregulated the expression of Netrin-1 and its receptor Deleted in Colorectal Cancer (DCC). Rho GTPase signaling is involved in interactions of Netrin-1 and DCC. PZT activated RhoA. Dramatic decrease of Cdc42 and Rac1 was also observed after PZT treatment. RhoA inhibitor Clostridium botulinum C3 exoenzyme (C3-Exo) prevented the PZT-induced downregulation of Netrin-1 and DCC. We suggest that PZT can promote axonal guidance growth by downregulation of Netrin-1 and DCC to mediate axonal repulsive responses via the Rho GTPase signaling pathway. Obviously, piezoelectric materials may provide a new approach for axonal recovery and be beneficial for clinical therapy in the future. PMID:24203571

  6. A circular array transducer for photoacoustic imaging by using piezoelectric single crystal lead magnesium niobate–lead zirconate titanate

    NASA Astrophysics Data System (ADS)

    Cao, Yonggang; Ha, Kanglyeol; Kim, Moojoon; Kang, Hyunwook; Oh, Jung-Hwan; Kim, Jungsoon

    2015-07-01

    The ultrasound transducers of which center frequencies are lower than 10 MHz are commonly used in low frequency photoacoustic (PA) imaging systems. However, the improvement of their sensitivity is still needed to detect weak PA signals. In this study, a circular array transducer was constructed by using 120 needle hydrophones made of piezoelectric single crystal lead magnesium niobate–lead zirconate titanate (PMN–PZT). The needle hydrophone was designed to have high sensitivity and wide bandwidth through the Krimtholz–Leedom–Matthaei (KLM) simulation of receiving impulse response. The sensitivity of the fabricated PMN–PZT hydrophone was compared with a commercial poly(vinylidene fluoride) (PVDF) needle hydrophone. The usefulness of the circular array transducer was demonstrated by applying it to a PA system for obtaining images.

  7. Re-poling process for piezoelectric-based multilayer ceramic capacitors force sensor

    NASA Astrophysics Data System (ADS)

    Lin, Keng-Ren; Chang, Chih-Han; Chiang, Cheng-Hung; Lin, Che-Hsin

    2013-04-01

    This study presents an industrial-grade piezoelectric-based multilayer ceramic capacitors (MLCCs) force sensor. In order to increase the sensitivity and reduce the variation of different MLCCs, a simple re-poling process is adopted by applying an external electric field at the Curie temperature of MLCCs. Results indicate that the re-poling treatment improved up to 100-fold for the force detection sensitivity and reduced the variation for the output force response by 10-fold in comparison with the MLCC sensors without re-poling.

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

    NASA Astrophysics Data System (ADS)

    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

    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

  9. Microstructures and Dielectric Characteristics of Ultrafine-Grained Barium Titanate-Based Ceramics for Base-Metal-Electrode Multilayer Ceramic Capacitors Applications

    NASA Astrophysics Data System (ADS)

    Wang, Tian; Wang, Xiaohui; Song, Tae-Ho; Li, Longtu

    2007-10-01

    Ultrafine-grained ceramics based on barium titanate for base-metal-electrode multilayer ceramic capacitors (BME-MLCCs) applications have been prepared. X-ray diffraction analysis was used to identify the phase compositions of the ceramics. The microstructures were characterized by scanning electron microscopy and transmission electron microscopy. The effects of different dopant contents on the crystal structures, grain growth, microstructures, and dielectric characteristics of the ceramics were investigated. Desired core-shell structures have been observed and the relationships of composition, crystal structure, grain growth, and microstructure have been discussed. The present ceramics show an average grain size of 180 nm and homogeneous microstructures, as well as a high dielectric constant, a low degree of dielectric loss and good X7R temperature characteristics, which would be promising candidates for next-generation BME-MLCC applications.

  10. Effect of porosity on dielectric properties and microstructure of porous PZT ceramics

    Microsoft Academic Search

    B. Praveen Kumar; H. H. Kumar; D. K. Kharat

    2006-01-01

    Porous piezoelectric materials are of great interest because of their high hydrostatic figure of merit and low sound velocity, which results in to low acoustic impedance and efficient coupling with medium. Porous lead zirconate titanate (PZT) ceramics with varying porosity was developed using polymethyl methacrylate by burnable plastic spheres (BURPS) process. The porous PZT ceramics were characterized for dielectric constant

  11. Microstructures, dielectric, and piezoelectric properties of W/Cr co-doped Bi4Ti3O12 ceramics

    NASA Astrophysics Data System (ADS)

    Chen, Yu; Liang, Dayun; Wang, Qingyuan; Zhu, Jianguo

    2014-08-01

    W/Cr co-doped Bi4Ti3O12 (BTWC) ceramics {Bi4Ti3-xWxO12 + x + 0.2 wt. % Cr2O3 (x = 0-0.1)} with a high piezoelectricity were prepared by a conventional ceramic process, and effects of W/Cr dopant on the microstructures, dielectric, and piezoelectric properties of ceramics were explored. It is found that W6+ modified the grain morphology and size of ceramics, promoting the forming of the regular schistose grains with a size of ˜10 ?m in the ceramic at x = 0.05. BTWC ceramics showed a continuous decrease in Tc and a gradual increase in ?r with the increasing W doping content. While the hard-doping of Cr2O3 decreased, the TK? and tan ? of ceramics available. All the ceramics keep the nature of first-order transition and displacive ferroelectrics. The d33 and kp of BTWC ceramics were remarkably improved by the soft-doping of W6+. Excellent electrical properties (e.g., Tc = 638 °C, ?r = 146, tan ? = 0.56%, TK? (500 °C) = 1.30 × 10-3/ °C, ? (500 °C) = 4.08 × 10-5 s, d33 = 28 pC/N, and kp = 6.17%) have been achieved in Bi4Ti2.95W0.05O12.05 + 0.2 wt. % Cr2O3 ceramic. Such a material can be a promising candidate for high-temperature piezoelectric applications.

  12. Thermal Reliability of Alkaline Niobate-Based Lead-Free Piezoelectric Ceramics

    NASA Astrophysics Data System (ADS)

    Tanaka, Daisuke; Tsukada, Takeo; Furukawa, Masahito; Wada, Satoshi; Kuroiwa, Yoshihiro

    2009-09-01

    Alkaline niobate-based (K,Na,Li,Ba,Sr)(Nb,Ta,Zr)O3 (ANSZ) ceramics were prepared by conventional sintering process, and their piezoelectric properties were measured. The Curie temperature (TC) of the ANSZ ceramic was 278 °C. The electromechanical coupling factor (kp) and the piezoelectric constant (d33) were 45.5% and 295 pC/N, respectively, and the dielectric permittivity (?33T/?0) was 1610 at room temperature. The thermal reliability was tested by 1000 cycles of thermal shock with temperatures ranging from -55 to 125 °C. The change in d33 of ANSZ was compared with that of commercial Pb(Zr,Ti)O3 after 1000 cycles of thermal shock. The phase transition behavior of ANSZ was investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) simultaneous measurement. No appreciable endothermic peak accompanied by a polymorphic phase transition was observed on the DSC curve. The crystalline structure was investigated in detail by XRD measurement with high-energy synchrotron radiation. The coexistence of two ferroelectric phases in a wide temperature range (from -175 to 150 °C) was observed.

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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.

  14. Design of Total Sliding-Mode-Based Genetic Algorithm Control for Hybrid Resonant-Driven Linear Piezoelectric Ceramic Motor

    Microsoft Academic Search

    Rong-Jong Wai; Ching-Hsiang Tu

    2007-01-01

    This study presents a total sliding-mode-based genetic algorithm control (TSGAC) system for a linear piezoelectric ceramic motor (LPCM) driven by a newly designed hybrid resonant inverter. First, the motor configuration and driving circuit of an LPCM are introduced, and its hypothetical dynamic model is represented by a nonlinear function with unknown system parameters. In the hybrid resonant drive system, it

  15. Electric properties of Holmium substituted SrBi4Ti4O15ceramic for High Temperature Piezoelectric Applications

    Microsoft Academic Search

    P. Sarah

    2011-01-01

    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

  16. Piezoelectric and ferroelectric properties of Bi0.5(Na1-x-yKxAgy)0.5TiO3 lead-free piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Liao, Yunwen; Xiao, Dingquan; Lin, Dunmin

    2008-01-01

    Lead-free piezoelectric ceramics Bi0.5(Na1-x-yKxAgy)0.5TiO3 [BNKAT(x/y)] have been synthesized by the mixed oxide method. The effects of the amount of K+ and Ag+ on the electrical properties were examined. X-ray diffraction patterns indicate that K+ and Ag+ ions partially substitute for the Na+ ions in Bi0.5Na0.5TiO3 and form a solid solution during sintering. At room temperature, the ceramics exhibit good performances with piezoelectric constant d33=189 pC/N, electromechanical coupling factor kp=35.0%, remanent polarization Pr=39.5 ?C/cm2, and coercive field Ec=3.3 kV/mm, respectively. The curves of the dielectric constant ?r and loss tangent tan ? versus temperature show that the transition temperature from ferroelectric to anti-ferroelectric phase decreases with increasing the K+ content for the compositions researched. The dependencies of kp and polarization versus electric (P E) hysteresis loops on temperature reveal that the depolarization temperature Td of BNKAT(0.15/0.015) ceramics, which have good piezoelectric properties (d33=134 pC/N, kp=32.5%) and strong ferroelectricity (Pr=39.5 ?C/cm2, Ec=4.1 kV/mm) at room temperature, is above 160 °C.

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    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.

  18. An in situ diffraction study of domain wall motion contributions to the frequency dispersion of the piezoelectric coefficient in lead zirconate titanate

    SciTech Connect

    Seshadri, Shruti B.; Prewitt, Anderson D.; Jones, Jacob L. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)] [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Studer, Andrew J. [Bragg Institute, ANSTO, Lucas Heights, New South Wales 2234 (Australia)] [Bragg Institute, ANSTO, Lucas Heights, New South Wales 2234 (Australia); Damjanovic, Dragan [Laboratory of Ceramics, Institute of Materials, Swiss Federal Institute of Technology-EPFL, 1015 Lausanne (Switzerland)] [Laboratory of Ceramics, Institute of Materials, Swiss Federal Institute of Technology-EPFL, 1015 Lausanne (Switzerland)

    2013-01-28

    The contribution of non-180 Degree-Sign domain wall displacement to the frequency dependence of the longitudinal piezoelectric coefficient has been determined experimentally in lead zirconate titanate using time-resolved, in situ neutron diffraction. Under subcoercive electric fields of low frequencies, approximately 3% to 4% of the volume fraction of non-180 Degree-Sign domains parallel to the field experienced polarization reorientation. This subtle non-180 Degree-Sign domain wall motion directly contributes to 64% to 75% of the magnitude of the piezoelectric coefficient. Moreover, part of the 33 pm/V decrease in piezoelectric coefficient across 2 orders of magnitude in frequency is quantitatively attributed to non-180 Degree-Sign domain wall motion effects.

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

    NASA Astrophysics Data System (ADS)

    Cao, Wenwu; Zhang, Q. M.; Cross, L. E.

    1992-12-01

    Inhomogeneous displacement profiles have been derived for a single-rod composite and a single-tube 1-3 ceramic-polymer composite under both uniaxial and hydrostatic stress. The effective piezoelectric constants for the composites have been derived in terms of the ceramic content, the piezoelectric and elastic constants of each component, and the aspect ratio of the ceramic rod. The stress concentration inside both phases is derived from the calculated inhomogeneous displacement profiles. It is found that only a finite portion of the polymer in the vicinity of the ceramic-polymer interface actually contributes to the stress transfer, and the induced additional stress on the ceramic also has a higher magnitude near the interface. The theoretical results quantitatively predict the performance of a given 1-3 structure, and can be used to optimize the design parameters, such as ceramic content, aspect ratio of the ceramic rods, rod geometry and rod arrangement, resin hardness, etc., for 1-3 structures designed for specific purposes.

  20. Current limiting by n-type barium titanate ceramics having no positive temperature coefficient in resistance

    SciTech Connect

    Kutty, T.R.N.; Ravi, V. (Materials Research Centre, Bangalore (India). Indian Institute of Science)

    1993-01-01

    Stable current-limiting characteristics are observed for n-BaTiO[sub 3] ceramics which do not exhibit positive temperature coefficient in resistance (PTCR). These ceramics have been prepared by reannealing the sintered polycrystalline n-BaTiO[sub 3] after painting on the disks with low melting mixtures of PbO+Bi[sub 2]O[sub 3]+B[sub 2]O[sub 3] and thereby modifying the grain boundary layer regions. The power handling capability can be altered by the addition of isovalent lattice substituents as well as the grain boundary layer modifiers such as Al[sub 2]O[sub 3]+SiO[sub 2]+TiO[sub 2] and controlling the donor concentrations in the bulk by regulating the oxygen content in the sintering atmosphere. The current-limiting in semiconducting titanates arises out of the combined influence of joule-heating that modifies the diffuse phase transition and the field effect by way of charge carrier tunneling across the asymmetric barriers at the grain boundary regions.

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

    Microsoft Academic Search

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

    1998-01-01

    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

  2. Thickness-induced resonance-based complex permittivity measurement technique for barium strontium titanate ceramics at microwave frequency

    Microsoft Academic Search

    Song Xia; Zhuo Xu; Xiaoyong Wei

    2009-01-01

    Thickness-induced resonance would be the major factor of uncertainty for complex permittivity measurement by using transmission\\/reflection method when the thickness of sample is several integer multiples of the half wavelength. A new technique for complex permittivity measurement was presented in this paper using the thickness-induced resonance for barium strontium titanate (BST) ceramics at microwave frequency. Simulated and experimental results show

  3. Fracture mechanisms in ferroelectric-ferroelastic lead zirconate titanate (Zr:Ti = 0. 54:0. 46) ceramics

    Microsoft Academic Search

    Karun Mehta; Anil V. Virkar

    1990-01-01

    Fracture toughness, {ital K}{sub IC}, of a single-phase commercial lead zirconate titanate (PZT) ceramic of tetragonal structure was measured using the single edge notched beam method above and below the Curie temperature. Domain switching (poling) under electrical and mechanical loading was examined using x-ray diffraction. Surface grinding, electrical poling, and mechanical poling caused crystallographic texture. Similar texture, indicative of domain

  4. On the mechanism of high piezoelectric anisotropy in lead titanate-based ferroelectrics

    SciTech Connect

    Topolov, V.Y.; Turik, A.V.; Chernobabov, A.I. [Rostov State Univ., Rostov-na-Donu (Russian Federation)

    1994-09-01

    The physical causes for the high anisotropy of piezoelectric moduli d{sub 33}{sup *}/{vert_bar}d{sub 31}{sup *}{vert_bar} in polycrystalline ferroelectrics (Pb{sub 1{minus}x}M{sub x})TiO{sub 3} with M = Ca, Sr, and Ba at 0.10 {le} x {le} 0.33, and Pb(Zr{sub 1{minus}y}Ti{sub y})O{sub 3} at 0.6 {le} y {le} 1 are analyzed. The physical parameters of the corresponding single-domain crystals are estimated. The features of the concentration dependences of piezoelectric moduli d{sub ij}{sup *} and their anisotropy are determined. These features are related to the behavior of the dielectric constants, electrostriction coefficients, and unit-cell parameters for single-domain crystals and to the domain structure of separate crystallites. 13 refs., 3 figs., 2 tabs.

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

    NASA Astrophysics Data System (ADS)

    Ma, Fengde D.; Wang, Yu U.

    2015-03-01

    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.

  6. Phase Transitions in Lead-free Piezoelectric Ceramics Monitored by the Resonance Method

    NASA Astrophysics Data System (ADS)

    Pardo, L.; García, A.; Brebøl, K.; Mercadelli, E.; Galassi, C.

    Ferroelectrics, like batio3 (bt) or binatio3 (bnt), were studied in the 1950s and are now revisited, due to the need for lead-free piezoceramics, according to worldwide directives for environmental protection. Poling some of these materials has shown a different physical mechanism than ferroelectric domain orientation, involving field-induced structural phase transitions from pseudo-cubic phases to ferro-piezoelectrically active ones. They also depolarize below the curie temperature due to a structural phase transition. Both poling and thermal depoling can be monitored by the measurement of the electromechanical resonances. Depoling of (1-x) bnt-xbt ceramics with x=0.04 (bnbt4) is here considered as a case study.

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    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.

  8. Enhanced ferroelectricity, piezoelectricity, and ferromagnetism in Nd-modified BiFeO3-BaTiO3 lead-free ceramics

    NASA Astrophysics Data System (ADS)

    Zheng, Qiaoji; Luo, Lingling; Lam, Kwok Ho; Jiang, Na; Guo, Yongquan; Lin, Dunmin

    2014-11-01

    Lead-free multiferroic ceramics of 0.75Bi1-xNdxFeO3 - 0.25BaTiO3 + 1 mol. % MnO2 were prepared by a conventional ceramic technique and their structure, piezoelectricity, and multiferroicity were studied. The ceramics sintered at 890-990 °C possess a pure perovskite structure. A morphotropic phase boundary of rhombohedral and monoclinic phases is formed at x = 0.05. A small amount of Nd improves the ferroelectric and piezoelectric properties of the ceramics. The ferroelectric-paraelectric phase transition becomes gradually diffusive with x increasing. After the addition of Nd, the ferromagnetism of the ceramics is greatly enhanced by ˜320%. The increase in sintering temperature improves significantly the ferroelectric, piezoelectric, and ferromagnetic properties of the ceramics. The ceramics with x = 0.05 sintered at 950-990 °C possess improved ferroelectricity, piezoelectricity, magnetism and insulation with Pr of 16.5-17.5 ?C/cm2, d33 of 113-121 pC/N, Mr of 0.127-0.138 emu/g, R of ˜5 × 109 ?.cm and high TC of 473-482 °C, indicating that the ceramic is a promising candidate for room-temperature multiferroic and high-temperature piezoelectric materials.

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

    PubMed Central

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

    2011-01-01

    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

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

    NASA Astrophysics Data System (ADS)

    McNulty, Thomas Francis

    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.

  11. Effect of Ceramic Processing Methods on Photostrictive Ceramics

    Microsoft Academic Search

    P. Poosanaas; A. Dogan; A. V. Prasadarao; S. Komarneni; K. Uchino

    1999-01-01

    Lanthanum-modified lead zirconate titanate (PLZT) ceramics (3\\/52\\/48) doped with 0.5 at.% WO3 were prepared by three different processing methods, coprecipitation, sol-gel and conventional oxide mixing techniques, to investigate the effect of processing route on photovoltaic and photostrictive properties. The piezoelectric constant (d33) was observed to be independent of processing technique. Photovoltaic and photo-induced strain were found to get enhanced with

  12. Crystal structure and electrical properties of bismuth sodium titanate zirconate ceramics.

    PubMed

    Rachakom, Ampika; Jaiban, Panupong; Jiansirisomboon, Sukanda; Watcharapasorn, Anucha

    2012-01-01

    Lead-free bismuth sodium titanate zirconate (Bi0.5Na0.5Ti1-xZrxO3 where x = 0.20, 0.35, 0.40, 0.45, 0.60, and 0.80 mole fraction) [BNTZ] ceramics were successfully prepared using the conventional mixed-oxide method. The samples were sintered for 2 h at temperatures lower than 1,000°C. The density of the BNTZ samples was at least 95% of the theoretical values. The scanning electron microscopy micrographs showed that small grains were embedded between large grains, causing a relatively wide grain size distribution. The density and grain size increased with increasing Zr concentration. A peak shift in X-ray diffraction patterns as well as the disappearance of several hkl reflections indicated some significant crystal-structure changes in these materials. Preliminary crystal-structure analysis indicated the existence of phase transition from a rhombohedral to an orthorhombic structure. The dielectric and ferroelectric properties were also found to correlate well with the observed phase transition. PMID:22221595

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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.

  14. Crystal structure and electrical properties of bismuth sodium titanate zirconate ceramics

    PubMed Central

    2012-01-01

    Lead-free bismuth sodium titanate zirconate (Bi0.5Na0.5Ti1-xZrxO3 where x = 0.20, 0.35, 0.40, 0.45, 0.60, and 0.80 mole fraction) [BNTZ] ceramics were successfully prepared using the conventional mixed-oxide method. The samples were sintered for 2 h at temperatures lower than 1,000°C. The density of the BNTZ samples was at least 95% of the theoretical values. The scanning electron microscopy micrographs showed that small grains were embedded between large grains, causing a relatively wide grain size distribution. The density and grain size increased with increasing Zr concentration. A peak shift in X-ray diffraction patterns as well as the disappearance of several hkl reflections indicated some significant crystal-structure changes in these materials. Preliminary crystal-structure analysis indicated the existence of phase transition from a rhombohedral to an orthorhombic structure. The dielectric and ferroelectric properties were also found to correlate well with the observed phase transition. PMID:22221595

  15. Enhanced mechanical properties in Ag-particle-dispersed PZT piezoelectric composites for actuator applications

    Microsoft Academic Search

    H. L. Zhang; J.-F. Li; B.-P. Zhang; W. Jiang

    2008-01-01

    Functional ceramics naturally have inferior mechanical properties. This study shows that incorporating Ag into lead zirconate titanate (PZT) piezoelectric ceramics by co-firing in air at 1200°C is effective for mechanical property enhancement. The Ag addition has increased the fracture strength ?f from 69MPa for monolithic PZT to 129MPa for PZT–15% Ag composite, and increased the corresponding fracture toughness KIC from

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

    NASA Technical Reports Server (NTRS)

    Sehirlioglu, Alp; Sayir, Ali

    2008-01-01

    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.

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

    Microsoft Academic Search

    G. L. Yuan; Siu Wing

    2006-01-01

    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 <30 mA\\/m2 even at a high electric field

  18. Thickness-induced resonance-based complex permittivity measurement technique for barium strontium titanate ceramics at microwave frequency.

    PubMed

    Xia, Song; Xu, Zhuo; Wei, Xiaoyong

    2009-11-01

    Thickness-induced resonance would be the major factor of uncertainty for complex permittivity measurement by using transmission/reflection method when the thickness of sample is several integer multiples of the half wavelength. A new technique for complex permittivity measurement was presented in this paper using the thickness-induced resonance for barium strontium titanate (BST) ceramics at microwave frequency. Simulated and experimental results show that there are some resonance peaks on the transmittance versus frequency curve and the complex permittivity can be calculated from the resonance. PMID:19947747

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

    PubMed

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

    2001-07-01

    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

  20. Hydrogen diffusion in Lead Zirconate Titanate and Barium Titanate

    SciTech Connect

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

    2012-08-28

    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.

  1. Thermal lens and Auger upconversion losses' effect on the efficiency of Nd3+-doped lead lanthanum zirconate titanate transparent ceramics

    NASA Astrophysics Data System (ADS)

    de Camargo, Andrea S. S.; Jacinto, Carlos; Catunda, Tomaz; Nunes, Luiz Antonio De O.; Garcia, Ducinei; Eiras, José Antonio

    2006-10-01

    A thorough investigation of optical losses for the 1064nm emission in Nd3+-doped lead lanthanum zirconate titanate (PLZT) transparent ceramics is presented. Thermal lens experiments were carried out to evaluate thermo-optical properties and the fluorescence quantum efficiency of the emitting level 4F3/2. Excited-state absorption losses were measured in the emitting wavelength region, and the Auger upconversion energy transfer parameter ? was calculated. By using ?, the pump-intensity dependence of the optical gain at 1064nm, the fluorescence quantum efficiency, and the generation of heat in the ceramic were simulated for a high 803nm pump-power regime. Since the radiative and nonradiative losses in Nd:PLZT were verified to be considerably lower than in various commercial laser crystals and glasses, it is suggested that this material might become an interesting alternative for high-power laser emission.

  2. Enhanced Photovoltaic Response in Lead Lanthanum Zirconate-Titanate Ceramics with A-Site Deficient Composition for Photostrictor Application

    Microsoft Academic Search

    Kazuhiro Nonaka; Morito Akiyama; Chao-Nan Xu; Tsuyoshi Hagio; Masahiro Komatsu; Akira Takase

    2000-01-01

    Samples of (Pb0.97, La0.03)(Zr0.52, Ti0.48)1-0.03\\/4O3 (PLZT) ceramics with and without an A-site deficient composition of 1 mol% in ABO3 perovskite structures have been prepared by sintering at 1200°C for 2 h to investigate the photovoltaic response upon UV illumination, as well as the ferroelectric and piezoelectric parameters such as the polarization-electric field (P-E) hysteresis curve, strain constant, and dielectric constant.

  3. The effects of porosity, electrode and barrier materials on the conductivity of piezoelectric ceramics in high humidity and dc electric field

    NASA Astrophysics Data System (ADS)

    Weaver, P. M.; Cain, M. G.; Stewart, M.; Anson, A.; Franks, J.; Lipscomb, I. P.; McBride, J. W.; Zheng, D.; Swingler, J.

    2012-04-01

    Prolonged operation of piezoelectric ceramic devices under high dc electric fields promotes leakage currents between the electrodes. This paper investigates the effects of ceramic porosity, edge conduction and electrode materials and geometry in the development of low resistance conduction paths through the ceramic. Localized changes in the ceramic structure and corresponding microscopic breakdown sites are shown to be associated with leakage currents and breakdown processes resulting from prolonged operation in harsh environments. The role of barrier coatings in mitigating the effects of humidity is studied, and results are presented on improved performance using composite diamond-like carbon/polymer coatings. In contrast to the changes in the electrical properties of the ceramic, the measurements of the piezoelectric properties showed no significant effect of humidity.

  4. Low-temperature sintering and phase transition of zinc titanate ceramics with V 2O 5 and B 2O 3 addition

    Microsoft Academic Search

    Xiangchun Liu; Feng Gao; Lili Zhao; Changsheng Tian

    2007-01-01

    V2O5 and B2O3-doped (abbreviated to V–B) zinc titanate ceramics were prepared by a conventional mixed-oxide method combined with a chemical processing. Fine particle powders were prepared by chemical processing to activate the formation of ZnTiO3 and to improve the sinterability. The effects of V–B addition on the low-temperature sintering behavior, the phase-structure and dielectric properties of ceramics were investigated, and

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

    E-print Network

    York, Robert A.

    Strontium 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 films, piezoelectric resonators. I. INTRODUCTION Strontium titanate (STO) and barium strontium titanate

  6. Study of polymorphic phase boundary in (Na,K,Li) (Nb,Ta,Sb)O3 piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaokun; Zhang, Boping; Zhu, Lifeng; Zhao, Lei; Zhou, Pengfei

    2014-02-01

    Li, Ta and Sb co-doped (Na,K)NbO3 ceramics have been widely investigated due to the significantly enhanced piezoelectric properties attributed to the polymorphic phase transition (PPT). An empirical discriminant k = x/0.3 + y/0.3 + z/0.06 to estimate the PPT composition of Liz(Na0.5+?K0.5-?)1-zNb1-x-yTaxSbyO3 ceramics was deduced based on a displayed phase diagram between the phase structure and doping contents. The phase structure could be conveniently estimated by k, in which a PPT appeared in the vicinity of k = 1, crossing O symmetry at k < 1 and T symmetry at k > 1. Around k = 1, a series of LizNa0.52K0.48-zNb0.90Ta0.05Sb0.05O3 ceramics was prepared by a traditional solid-state reaction in a narrow range 0.03 ? z ? 0.05. A PPT at room temperature appeared critically in the z = 0.04 composition, indicating a good feasibility of the suggested empirical equation to determine the critical PPT composition in the present study. The optimized piezoelectric properties d33 255 pC N-1 and kp 35.0% were attained due to the PPT behaviour.

  7. Effective moduli of granular and layered composites with piezoelectric constituents

    NASA Astrophysics Data System (ADS)

    Olson, Tamara; Avellaneda, Marco

    1993-07-01

    The effective elastic and dielectric moduli of a composite made from piezoelectric materials are examined, with particular emphasis on applications to unpoled piezoelectric ceramics and layered materials. Explicit formulae for the effective moduli and coupling of a layered material are derived. A self-consistent estimate of the moduli of an isotropic polycrystal is obtained through an effective medium approximation (EMA), which takes into account the interaction between each individual grain and the surrounding composite. This estimate shows that the grains behave as uncoupled grains with electric and elastic constants modified by the behavior of surrounding grains. A similar effect is also observed in bounds (established via classical variational principles) on the moduli of a statistically isotropic polycrystal. Numerical implementation of the EMA and bounds show good agreement with data for unpoled barium titanate ceramic. For a general composite with piezoelectric constituents, it is shown that the effective electromechanical coupling can be bounded by the largest coupling factor of the components.

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

    NASA Astrophysics Data System (ADS)

    Gupta, Shashaank; Belianinov, Alexei; Baris Okatan, Mahmut; Jesse, Stephen; Kalinin, Sergei V.; Priya, Shashank

    2014-04-01

    ?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 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 determined by the crystal structure.

  9. Piezoelectric dilatometric analysis using homodyne and heterodyne laser interferometry

    NASA Astrophysics Data System (ADS)

    Delahoussaye, Keith

    The electromechanical coupling of piezoelectric materials has been widely studied since such property is found to be a key element of enhanced sensitivity in piezoelectric sensors or actuators. However a unified view of this coupling as function of frequencies verified using multiple measurement techniques has not previously been available. This study examines and compares multiple optical based homodyne and heterodyne interferometry techniques for piezoelectric displacement measurement, over a wide range of frequencies from DC to 20 MHz. A custom configured homodyne optical interferometer and a commercial heterodyne Laser Doppler Vibrometer are used in the study. Because the frequency ranges used by these devices overlap, it is possible to compare the results. Ferroelectric lead titanate PbTiO3 (PT) ceramic sample with high ferroelectric strain is studied in this work. Frequency dependence of the electromechanical displacement is obtained using multiple techniques and the emphasis of the interrogations is given to frequencies near piezoelectric resonances.

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

    E-print Network

    Cao, Wenwu

    . This lossy nature suggests that the nonlinearities in a ferroelectric ceramic are generated by the domain of nonlinearity) all indicate the extrinsic nature of the nonlinear behavior of ferroelectric ceramics behavior of piezoceramic materials is very important because ferroelectric ceramics are now widely used

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

    Microsoft Academic Search

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

    1995-01-01

    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

  12. Plate-like structure health monitoring based on ultrasonic guided wave technology by using bonded piezoelectric ceramic wafers

    NASA Astrophysics Data System (ADS)

    Liu, Zenghua; Zhao, Jichen; He, Cunfu; Wu, Bin

    2008-11-01

    Piezoelectric ceramic wafers are applied for the excitation and detection of ultrasonic guided waves to determine the health state of plate-like structures. Two PZT wafers, whose diameter is 11mm and thickness is 0.4mm respectively, are bonded permanently on the surface of a 1mm thick aluminum plate. One of these wafers is actuated by sinusoidal tone burst at various frequencies ranging from 100kHz to 500kHz, the other one is used as a receiver for acquiring ultrasonic guided wave signals. According to the amplitudes and shapes of these received signals, guided wave modes and their proper frequency range by using these wafers are determined. For the improvement of the signal-to-noise ratio, the Daubechies wavelet of order 40 is used for signal denoising as the mother wavelet. Furthermore, the detection of an artificial cylindrical through-hole defect is achieved by using S0 at 300kHz. Experimental results show that it is feasible and effective to detect defects in plate-like structures based on ultrasonic guided wave technology by using bonded piezoelectric ceramic wafers.

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

    E-print Network

    Atwater, Harry

    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

  14. Determination of metal impurities in advanced lead zirconate titanate ceramics by axial view mode inductively coupled plasma optical emission spectrometry.

    PubMed

    Villanueva Tagle, M E; Larrea Marín, M T; Martin Gavilán, O; Durruthy Rodríguez, M D; Calderón Piñar, F; Pomares Alfonso, M S

    2012-05-30

    An inductively coupled plasma optical emission spectrometry quantification method for the determination of Al, Ca, Cr Cu, Fe, Mn, Mg, Ni, Zn, Ba, K, In and Co in lead zirconate-titanate (PZT) ceramics, modified with strontium and chromium, was developed. Total digestion of ceramics was achieved with a HNO(3), H(2)O(2) and HF (ac) mixture by using a microwave furnace. The sensitivity of the net signal intensity respect to radiofrequency power (P) and nebulizer argon flow (F(N)) variations was strongly dependent of the total excitation energy of line (TEE). For lines with TEE near metastable atoms and ions of argon, an increment of the sensitivities to P and F(N) variation was observed. At robust plasma conditions the matrix effect was reduced for all matrices and analytes considered. The precision of analysis ranged from 3 to 13%, whereas the analytes recoveries in the spiked samples varied, mostly, from 90 to 110%. The detection limits of studied elements were from 0.004 to 10 mg kg(-1). PMID:22608413

  15. Nonplanar piezoelectric film structures

    Microsoft Academic Search

    Seppo Leppävuori; Arvi Kruusing; Antti Uusimäki

    1999-01-01

    Microengineered, non-planar piezoelectric structures can offer solutions to a variety of challenging problems arising in the microsystem technologies. Besides the piezoelectric polymers, which can easily be shaped, there has also been significant progress in developing fabrication technologies based on thin layers of the lead – zirconate – titanate family of piezoceramics. The processing methods include dip-casting, printing, cathodic electrosynthesis, electrolytic

  16. BaTiO3 piezoelectric microfiber composites for mechanical energy harvesting

    Microsoft Academic Search

    Peng Hu; Zhaoxian Xiong; Hao Xue; Jie Pan; Qingjun Lu; Xiaopeng Xiao

    2011-01-01

    In this paper, green microfibers of barium titanate precursor were prepared by the combination of Sol-Gel processing and Gel-spinning technique. The piezoelectric microfibers of ceramic BaTiO3 were sintered, with diameter of 15?m and length of 20mm, respectively. Interdigitated electrodes were printed on an epoxy resin substrate. BaTiO3 microfibers were then aligned on the interdigitated electrodes and covered with the solution

  17. Analysis of Piezoelectric Materials for Energy Harvesting Devices under High-g Vibrations

    Microsoft Academic Search

    Dongna Shen; Song-Yul Choe; Dong-Joo Kim

    2007-01-01

    We analyzed the miniaturized energy harvesting devices (each volume within 0.3 cm3) fabricated by using three types of piezoelectric materials such as lead zirconium titanate (PZT) ceramic, macro fiber composite (MFC) and poly(vinylidene fluoride) (PVDF) polymer to investigate the capability of converting mechanical vibration into electricity under larger vibration amplitudes or accelerations conditions (>= 1g, gravitational acceleration). All prototypes based

  18. Development of piezoelectric skin friction force vector transducer for a hypersonic wind tunnel

    NASA Technical Reports Server (NTRS)

    Kahng, S. K.

    1972-01-01

    A surface shear force transducer for use in impulse type hypersonic tunnels is described. Sensors are constructed of lead zirconate titanate composition piezoelectric ceramic materials. The diameter of the sensing diaphragm is 0.75 inches and overall transducer dimensions are 1.0 inch diameter and 0.625 inch height. Analysis of the tranducer is made to help design criteria and fabrication techniques. Discussions on design and fabrication techniques are presented as well as performance of transducers delivered.

  19. Dielectric properties and far infrared reflectivity of lanthanum aluminate–strontium titanate ceramics

    Microsoft Academic Search

    T. Shimada; K. Kura; S. Ohtsuki

    2006-01-01

    LaAlO3–SrTiO3 [(1?x) LAO–xSTO] ceramics were prepared by a conventional solid-phase reaction method using high-purity reagents. Far infrared reflectivity spectra for (1?x) LAO–xSTO ceramics were measured and eigenfrequencies and damping constants of the transverse and longitudinal optical modes were estimated in order to analyze the dielectric properties and lattice vibration parameters. The observed reflectivity spectra were fitted by 4 or 6

  20. Note: a high-sensitivity current sensor based on piezoelectric ceramic Pb(Zr,Ti)O3 and ferromagnetic materials.

    PubMed

    He, Wei; Li, Ping; Wen, Yumei; Zhang, Jitao; Yang, Aichao; Lu, Caijiang

    2014-02-01

    An electric current sensor using piezoelectric ceramic Pb(Zr,Ti)O3 (PZT) sandwiched between two high permeability cuboids and two NdFeB magnets is presented. The magnetic field originating from an electric wire is augmented by the high permeability cuboids. The PZT plate experiences an enhanced magnetic force and generates voltage output. When placed with a distance of d = 5.0 mm from the wire, the sensor shows a flat sensitivity of ?5.7 mV/A in the frequency range of 30 Hz-80 Hz and an average sensitivity of 5.6 mV/A with highly linear behavior in the current range of 1 A-10 A at 50 Hz. PMID:24593410

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

    NASA Astrophysics Data System (ADS)

    Toda, Kohji; Sawaguchi, Akihiro

    1991-01-01

    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.

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

    SciTech Connect

    Mukherjee, Binu [Department of Physics, Royal Military College of Canada, Kingston, Ontario K7K 7B4 (Canada)

    2008-07-29

    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.

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

    SciTech Connect

    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

    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.

  4. Structured Piezoelectric Composites: Materials and Applications

    Microsoft Academic Search

    D. A. Van den Ende

    2012-01-01

    The piezoelectric effect, which causes a material to generate a voltage when it deforms, is very suitable for making integrated sensors, and (micro-) generators. However, conventional piezoelectric materials are either brittle ceramics or certain polymers with a low thermal stability, which limits their practical application to certain specific fields. Piezoelectric composites, which contain an active piezoelectric (ceramic) phase in a

  5. Photovoltaic and photostrictive effects in lanthanum-modified lead zirconate titanate ceramics

    Microsoft Academic Search

    Patcharin Poosanaas

    1999-01-01

    Photostriction is the light induced strain in a material, arising from the combination of photovoltaic and converse-piezoelectric effects. The possibility of directly producing strain by light illumination, without any electrical lead wire connection, makes the photostrictive materials very attractive for potential usage in future generation wireless remote controlled micro-actuator and micro-sensor. However, for the fabrication of these devices, materials exhibiting

  6. Electromechanical resonance in ferrite-piezoelectric nanopillars, nanowires, nanobilayers, and magnetoelectric interactions

    E-print Network

    Srinivasan, Gopalan

    to nickel ferrite-lead zirconate titanate nanostructures on strontium titanate substrate or templateElectromechanical resonance in ferrite-piezoelectric nanopillars, nanowires, nanobilayers ME effects in the region of electromechanical resonance EMR for ferrite-piezoelectric nanobilayers

  7. Preparation and piezoelectric properties of textured PZT ceramics using PZT nano fibers

    Microsoft Academic Search

    Cai-feng Chen; Xiao-li Han; Jun Liu; Zhi-dan Ding

    2011-01-01

    PZT nano piezoelectric fibers were prepared by hydrothermal-template method. The effects of some reaction conditions on preparation were investigated, such as PH value, reaction temperature and time. The optimal hydrothermal conditions for preparing PZT nano fibers are that pH value is 13, reaction temperature is 190 °C, hydrothermal reactor filling degree is 60 %–70 %, reaction time is 10h, and

  8. Piezoelectric ceramic bimorph coupled to thin metal plate as cooling fan for electronic devices

    Microsoft Academic Search

    Ju Hyun Yoo; Jae Il Hong; Wenwn Cao

    2000-01-01

    Several types of piezoelectric fans for cooling electronic devices were constructed and tested at 60 Hz, 110 V and 220 V, respectively. The aim of the work is to investigate the possibility of replacing the rotary type of fan in some noise-sensitive electronic devices. Different vibrating metal plates were tested and analyzed theoretically. It is found that the resonant frequency

  9. Grain-oriented lead(magnesium(1\\/3)niobium(2\\/3))oxygen(3)-lead titanate ceramics prepared by templated grain growth

    Microsoft Academic Search

    Edward Michael Sabolsky

    2001-01-01

    Rhombohedral Pb(Mg1\\/3Nb2\\/3)O3-PbTiO 3 (PMN-PT) single crystals near the morphotropic phase boundary (MPB) show enhanced strain levels combined with exceedingly large piezoelectric and electromechanical coupling coefficients for -oriented and -poled crystal cuts. In principle, fiber-textured PMN-PT ceramics should possess a high fraction of the electromechanical and dielectric properties displayed by their single crystal counterparts. To investigate this, the Templated Grain Growth

  10. Fabrication of Lead-Free Lithium-Doped Na0.5K0.5NbO3 Piezoelectric Ceramics with Dense Grain Structure Using Sol-Gel Surface Coating

    NASA Astrophysics Data System (ADS)

    Lim, Sun Kyung; Han, Jeong Seon; Yoo, Ae Ri; Lee, Seong Eui; Lee, Hee Chul

    2013-10-01

    Lead-free piezoelectric 0.06(LiNbO3)-0.94(Na0.5K0.5)NbO3 (LNKN) ceramics in disc form were fabricated and characterized to acquire good electromechanical properties. A molding method including cold isostatic pressing (CIP) was used to form a dense and regular microstructure and suppress the cracking problems of LNKN ceramics during the following high-temperature sintering. The LNKN ceramic sintered at 1040 °C showed a high piezoelectric constant d33 of 170 pC/N owing to its high density. Furthermore, perovskite LNKN films with the same composition as the ceramics were fabricated using 2-methoxyethanol-based sol-gel solution. The sol-gel surface coating on the LNKN ceramics was found to be very effective for increasing the piezoelectric constant because of the interface stabilization effect leading to a uniform electric field in piezoelectric elements. As a result, we obtained the highest piezoelectric constant d33 of 183 pC/N. The lead-free LNKN ceramics are promising for applications in eco-friendly ferroelectric and piezoelectric devices.

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

    SciTech Connect

    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

    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.

  12. The Effect of Temperature on Bipolar Electrical Fatigue Behavior of Lead Zirconate Titanate Ceramics

    NASA Astrophysics Data System (ADS)

    Pojprapai, Soodkhet; Glaum, Julia

    2012-09-01

    The ferroelectric fatigue behavior of lead zirconate titanate was investigated under different temperatures (room temperature and 125°C). A bipolar electric field of ±1.5 kV/mm at a frequency of 50 Hz was applied to the samples up to 2 × 105 cycles. A markedly different fatigue rate was observed dependent on temperature. The fatigue degradation represented by the loss of polarization and strain increases with the number of cycles and is more pronounced in the case of the lower temperature. Brennan's model based on a logarithmic fatigue rate is applied to explain the temperature effect on fatigue behavior due to the pinning effect.

  13. Study of impedance parameters of cerium modified lead zirconate titanate ceramics

    Microsoft Academic Search

    Balgovind Tiwari; R. N. P. Choudhary

    2010-01-01

    A high-temperature solid-state reaction technique was used to prepare the polycrystalline samples of cerium (Ce) modified lead zirconate titanate with Zr\\/Ti ratio 65:35 (i.e., Pb(Zr0.65-xCexTi0.35)O3 (PZCT)). Preliminary X-ray structural analysis exhibits the formation of the new compositions of PZT. In order to study the compositional effects on the electrical properties (complex impedance Z*, complex modulus M*, electrical conductivity and relaxation

  14. Evaluation of polarization of embedded piezoelectrics by the thermal wave method.

    PubMed

    Suchaneck, Gunnar; Eydam, Agnes; Hu, Wenguo; Kranz, Burkhart; Drossel, Welf-Guntram; Gerlach, Gerald

    2012-09-01

    This work demonstrates the benefit of the thermal wave method for the evaluation of the polarization state of embedded piezoelectrics. Two types of samples were investigated: A low-temperature co-fired ceramics (LTCC)/lead zirconate titanate (PZT) sensor-actuator and a macro-fiber composite (MFC) actuator. At modulation frequencies below 10 Hz, the pyroelectric response was governed by thermal losses to the embedding layers. Here, the sample behavior was described by a harmonically heated piezoelectric plate exhibiting heat losses to the environment characterized by a single thermal relaxation time. PMID:23007766

  15. Evaluation of electromechanical coupling parameters of piezoelectric materials by using piezoelectric cantilever with coplanar electrode structure in quasi-stasis.

    PubMed

    Zheng, Xuejun; Zhu, Yuankun; Liu, Xun; Liu, Jing; Zhang, Yong; Chen, Jianguo

    2014-02-01

    Based on Timoshenko beam theory, a principle model is proposed to establish the relationship between electric charge and excitation acceleration, and in quasi-stasis we apply the direct piezoelectric effect of multilayer cantilever with coplanar electrode structure to evaluate the piezoelectric strain coefficient d15 and electromechanical coupling coefficient k15. They are measured as 678 pC/N and 0.74 for the commercial piezoelectric ceramic lead zirconate titanate (PZT-51) bulk specimen and 656 pC/N and 0.63 for the lead magnesium niobate (PMN) bulk specimen, and they are in agreement with the calibration and simulation values. The maximum of relative errors is less than 4.2%, so the proposed method is reliable and convenient. PMID:24474142

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

    SciTech Connect

    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

    (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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    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).

  18. Sintering Behaviour and Piezoelectric Properties of CuO-Added Lead-Free Bi(Na,K)TiO3 Ceramics

    Microsoft Academic Search

    Hyoung-Su Han; Nam-Binh Do; Ky-Nam Pham; Hyun-Deok Jang; Vu Diem Ngoc Tran; Weon-Pil Tai; Jae-Shin Lee

    2011-01-01

    Effect of excess CuO on the sintering behaviour and piezoelectric properties of Bi0.5(Na82K0.18)0.5TiO3 ceramics was investigated. The addition of small amount of excess CuO as low as 0.01 mol was quite effective to lower the sintering temperature (Ts) of BNKT ceramics down to 975°C which is 200°C lower than the Ts of pure BNKT (1175°C) without significant degradation of their

  19. Improvement of the piezoelectric properties in (K,Na)NbO3-based lead-free piezoelectric ceramic with two-phase co-existing state

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

    Two phases of (K,Na)NbO3 (KNN) co-exist in a KNN-based composite lead-free piezoelectric ceramic 0.910(K1-xNax)0.86Ca0.04Li0.02Nb0.85O3-?-0.042K0.85Ti0.85Nb1.15O5-0.036BaZrO3-0.0016Co3O4- 0.0025Fe2O3-0.0069ZnO system, over a wide range of Na fractions, where 0.56 ? x ? 0.75. The crystal systems of the two KNN phases are identified to tetragonal and orthorhombic by analyzing the synchrotron powder X-ray diffraction (XRD) data, high-resolution transmission electron microscopy (HR-TEM), and selected-area electron diffraction (SAD). In the range 0.33 ? x ? 0.50, the main component of the composite system is found to be single-phase KNN with a tetragonal structure. Granular nanodomains of the orthorhombic phase dispersed in the tetragonal matrix have been identified by HR-TEM and SAD for 0.56 ? x ? 0.75. Only a trace amount of the orthorhombic phase has been found in the SAD patterns at the composition x = 0.56. However, the number of orthorhombic nanodomains gradually increases with increasing Na content up to x < 0.75, as observed from the HR-TEM images. An abrupt increase and agglomeration of the nanodomains are observed at x = 0.75, where weak diffraction peaks of the orthorhombic phase have also become detectable from the XRD data. The maximum value of the electromechanical coupling coefficient, kp = 0.56, has been observed at the composition x = 0.56.

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

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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.

  1. Manganese-modified BiScO3–PbTiO3 piezoelectric ceramic for high-temperature shear mode sensor

    Microsoft Academic Search

    Shujun Zhang; Richard E. Eitel; Clive A. Randall; Thomas R. Shrout; Edward F. Alberta

    2005-01-01

    The bismuth-based perovskite solid solution (100?x)BiScO3?xPbTiO3 (BSPT) was investigated for use at temperatures up to 400 °C and above. The high-temperature resistivity, together with dielectric and piezoelectric behaviors of the shear mode for manganese-modified BSPT ceramics near the morphotropic phase boundary composition were studied. The resistivity and time constant were found to be 3×107 ? cm and 0.08 s, respectively,

  2. Manganese-modified BiScO3-PbTiO3 piezoelectric ceramic for high-temperature shear mode sensor

    Microsoft Academic Search

    Shujun Zhang; Richard E. Eitel; Clive A. Randall; Thomas R. Shrout; Edward F. Alberta

    2005-01-01

    The bismuth-based perovskite solid solution (100-x)BiScO3-xPbTiO3 (BSPT) was investigated for use at temperatures up to 400 °C and above. The high-temperature resistivity, together with dielectric and piezoelectric behaviors of the shear mode for manganese-modified BSPT ceramics near the morphotropic phase boundary composition were studied. The resistivity and time constant were found to be 3×107 Omega cm and 0.08 s, respectively,

  3. Phase transition behavior and electrical properties of lead-free (Ba1-xCax)(Zr0.1Ti0.9)O3 piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Tian, Ye; Chao, Xiaolian; Wei, Lingling; Liang, Pengfei; Yang, Zupei

    2013-05-01

    Lead-free (Ba1-xCax)(Zr0.1Ti0.9)O3(BCZT) ceramics were synthesized by conventional solid-state sintering process. The Ca ion substitutions on phase transition behavior, microstructure, ferroelectric and piezoelectric properties of BCZT ceramics were systemically investigated. The diffuse phase transition (DPT) behavior was suppressed, while the orthorhombic ? tetragonal (O?T) and rhombohedral ? orthorhombic (R?O) phase transitions were observed when the Ca content is at x = 0.05. Further increasing the Ca content, the DPT behavior gradually enhanced, and both the O?T and R?O phase transitions gradually evolved into R?T phase transition when the Ca content increases up to 0.15 at 25 °C. This behavior was related with phase structure and morphology, which significantly impacted the ferroelectric and piezoelectric properties near the R?T phase boundary. As a result, the sample with Ca contents of 0.15 shows the outstanding piezoelectric properties (with d33 = 572 pC/N, kp = 57%, Qm = 125, ?r = 4821, and tan ? = 0.015) while negligible change for the ferroelectric properties. The abnormal ferroelectric behavior and potential factor contributing to large piezoelectric response also were discussed.

  4. Dielectric, electromechanical, optical, and mechanical properties of lanthanum-modified lead titanate ceramics

    Microsoft Academic Search

    T. Yamamoto; HIDEJI IGARASHI; KIYOSHI OKAZAKI

    1983-01-01

    Dielectric, electromechanical, optical, and mechanical properties of hot-pressed lanthanum-modified PbTiOâ ceramics were measured as a function of crystal tetragonality, c\\/a, in a range of tetragonal-to-cubic phases. The results obtained in this study are summarized as follows: The c\\/a changes linearly as a function of lanthanum content. Similarly, Curie point changed linearly and remanent polarization, coercive field, and coupling factors decreased

  5. Bright reddish-orange emission and good piezoelectric properties of Sm2O3-modified (K0.5Na0.5)NbO3-based lead-free piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Hao, Jigong; Xu, Zhijun; Chu, Ruiqing; Li, Wei; Du, Juan

    2015-05-01

    Reddish orange-emitting 0.948(K0.5Na0.5)NbO3-0.052LiSbO3-xmol%Sm2O3 (KNN-5.2LS-xSm2O3) lead-free piezoelectric ceramics with good piezoelectric properties were fabricated in this study, and the photoluminescence and electrical properties of the ceramics were systematically studied. Results showed that Sm2O3 substitution into KNN-5.2LS induces a phase transition from the coexistence of orthorhombic and tetragonal phases to a pseudocubic phase and shifts the polymorphic phase transition (PPT) to below room temperature. The temperature stability and fatigue resistance of the modified ceramics were significantly improved by Sm2O3 substitution. The KNN-5.2LS ceramic with 0.4 mol. % Sm2O3 exhibited temperature-independent properties (25-150 °C), fatigue-free behavior (up to 106 cycles), and good piezoelectric properties (d33* = 230 pm/V, d33 = 176 pC/N, kp = 35%). Studies on the photoluminescence properties of the samples showed strong reddish-orange emission upon blue light excitation; these emission intensities were strongly dependent on the doping concentration and sintering temperature. The 0.4 mol. % Sm2O3-modified sample exhibited temperature responses over a wide temperature range of 10-443 K. The maximum sensing sensitivity of the sample was 7.5 × 10-4 K at 293 K, at which point PPT occurred. A relatively long decay lifetime ? of 1.27-1.40 ms and a large quantum yield ? of 0.17-0.19 were obtained from the Sm-modified samples. These results suggest that the KNN-5.2LS-xSm2O3 system presents multifunctional properties and significant technological potential in novel multifunctional devices.

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

    PubMed

    Pullar, Robert C

    2012-07-01

    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

  7. Enhanced dielectric and piezoelectric properties of xBaZrO3-(1-x)BaTiO3 ceramics

    NASA Astrophysics Data System (ADS)

    Dong, Liang; Stone, Donald S.; Lakes, Roderic S.

    2012-04-01

    xBaZrO3-(1-x)BaTiO3 solid solutions (x = 0, 0.04, 0.06, 0.08, 0.12, and 0.18) synthesized via conventional solid state reaction method exhibit piezoelectric coefficients comparable to those of "hard" PZT-8, PZT-4, and even "soft" PZT-5 A. Doping also improves the poling efficiency of xBaZrO3-(1-x)BaTiO3 ceramics. Study of temperature dependence of the dielectric and piezoelectric properties reveal the following. Doping lowered the Curie point but raised the temperatures of the other two transformations. The diffused phase transition behavior has been enhanced with increasing content of BaZrO3, but x ? 0.18 is not enough to show a relaxor behavior. Piezoelectric responses show peaks at transformation temperatures and exhibit the best stability in the orthorhombic phase. Significant improvement in room temperature piezoelectric and electromechanical responses (d33 = 420pC/N, d31 = -138pC/N, and kp = 49%) comparable to PZT-5 A is achieved at a composition of x = 0.06 (1400 °C 100 h sintered), which brings the rhombohedral-orthorhombic transition to the ambient temperature. Enhanced piezoelectric properties are mainly attributed to a series of microscopic phase transformations due to the presence of internal structural gradient. Other possible contributions such as domain structures and constrained negative stiffness effect have also been discussed.

  8. Measurements of the thermal, dielectric, piezoelectric, pyroelectric and elastic properties of porous PZT samples

    NASA Astrophysics Data System (ADS)

    Lang, Sidney B.; Ringgaard, Erling

    2012-06-01

    The introduction of porosity into ferroelectric ceramics has been of great interest in recent years. In particular, studies of porous lead-zirconate-titanate ceramic (PZT) have been made. In the research reported, samples of Ferroperm Pz27 with porosities of 20, 25 and 30% were studied. Very complete measurements were made of all of the physical properties relevant for ferroelectric applications including thermal conductivity and diffusivity, heat capacity, dielectric, pyroelectric, piezoelectric and elastic properties. Scanning electron micrographs indicated a change from 3-0 to 3-3 connectivity with increasing porosity. Although most of the physical properties are degraded by the presence of porosity, both piezoelectric and pyroelectric figures-of-merit are improved because of the markedly reduced relative permittivity. Porous ferroelectric ceramics are very promising materials for a number of applications.

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

    PubMed

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

    2015-01-01

    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

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

    SciTech Connect

    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

    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.

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

    SciTech Connect

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

    2009-04-15

    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.

  12. Giant piezoelectricity in potassium-sodium niobate lead-free ceramics.

    PubMed

    Wang, Xiaopeng; Wu, Jiagang; Xiao, Dingquan; Zhu, Jianguo; Cheng, Xiaojing; Zheng, Ting; Zhang, Binyu; Lou, Xiaojie; Wang, Xiangjian

    2014-02-19

    Environment protection and human health concern is the driving force to eliminate the lead from commercial piezoelectric materials. In 2004, Saito et al. [ Saito et al., Nature , 2004 , 432 , 84 . ] developed an alkali niobate-based perovskite solid solution with a peak piezoelectric constant d33 of 416 pC/N when prepared in the textured polycrystalline form, intriguing the enthusiasm of developing high-performance lead-free piezoceramics. Although much attention has been paid on the alkali niobate-based system in the past ten years, no significant breakthrough in its d33 has yet been attained. Here, we report an alkali niobate-based lead-free piezoceramic with the largest d33 of ?490 pC/N ever reported so far using conventional solid-state method. In addition, this material system also exhibits excellent integrated performance with d33?390-490 pC/N and TC?217-304 °C by optimizing the compositions. This giant d33 of the alkali niobate-based lead-free piezoceramics is ascribed to not only the construction of a new rhombohedral-tetragonal phase boundary but also enhanced dielectric and ferroelectric properties. Our finding may pave the way for "lead-free at last". PMID:24499419

  13. P-Type Polymer-Hybridized High-Performance Piezoelectric Nanogenerators

    E-print Network

    Wang, Zhong L.

    a breakthrough in realizing a high-performance flexible piezoelectric energy harvester for self devices. Piezoelectric energy harvesters using materials, such as lead zirconate titanate (PZTP-Type Polymer-Hybridized High-Performance Piezoelectric Nanogenerators Keun Young Lee, Brijesh

  14. Polar nanodomains and local ferroelectric phenomena in relaxor lead lanthanum zirconate titanate ceramics

    SciTech Connect

    Shvartsman, V.V.; Kholkin, A.L.; Orlova, A.; Kiselev, D.; Bogomolov, A.A.; Sternberg, A. [Department of Ceramics and Glass Engineering and Center for Research in Ceramic and Composite Materials (CICECO), University of Aveiro, 3810-193 Aveiro (Portugal); Department of Physics, Tver State University, 170000 Tver (Russian Federation); Institute of Solid State Physics, University of Latvia, LV-1063 Riga (Latvia)

    2005-05-16

    Transparent Pb{sub 0.9125}La{sub 0.0975}(Zr{sub 0.65}Ti{sub 0.35}){sub 0.976}O{sub 3} ceramics (conventionally abbreviated as PLZT 9.75/65/35) is a typical relaxor characterized by the absence of the ferroelectric order at the macroscopic scale. In this letter, we report on the observation of complex polar structures on the surface of this material via piezoresponse force microscopy (PFM). The irregular polarization patterns are associated with the formation of a glassy state, where random electric fields destroy the long-range ferroelectric order. The measure of the disorder, the correlation length of {approx}50 nm, was directly deduced from the PFM images. Local poling of relaxor ceramics resulted in the formation of a stable micron-size domain that could be continuously switched under varying dc bias (local relaxor-ferroelectric phase transition). Fractal analysis was applied to analyze the origin of local order in PLZT.

  15. Structural and optical properties of chromium-doped hexagonal barium titanate ceramics

    NASA Astrophysics Data System (ADS)

    Langhammer, H. T.; Müller, T.; Böttcher, R.; Abicht, H.-P.

    2008-02-01

    The influence of chromium on the crystallographic phase and the microstructure of ceramics with the nominal composition BaTiO3+0.04BaO+xCr2O3 (0<=x<=0.025) was investigated by systematic studies of x-ray diffraction (XRD) and electron paramagnetic resonance (EPR). At Cr concentrations <=0.1 mol% a hexagonal phase appears (room temperature). For nominal concentrations >=1.0 mol% the material is 100% hexagonal and its microstructure exhibits exaggerated, plate-like grains with a mean grain size >=100 µm (sintering temperature 1400 °C). In the hexagonal phase the EPR-active CrTi3+ ions substitute both for Ti(1) (corner-sharing octahedron) and Ti(2) (face-sharing octahedron) sites. In air-sintered ceramics chromium is incorporated with valence states 3+ and 4+, whereas for reduced samples the valence state 3+ predominates. Optical transmission both of air-sintered and reduced samples doped with nominally 5.0 mol% Cr was measured in the visible light region. The absorption spectra exhibit distinct absorption bands. Their assignment to chromium defects with different valence states is discussed. The Jahn-Teller distortion caused by the electron configuration d2 (CrTi4+) is proposed as the driving force for the high-temperature phase transition cubic \\to hexagonal.

  16. Reactive sintering of plutonium-bearing titanates.

    SciTech Connect

    Hash, M. C.

    1999-06-24

    Titanate ceramics are being developed for the immobilization of weapons-grade plutonium. These multi-phase ceramics are intended to be both corrosion and proliferation resistant. Reactive sintering techniques were refined to reproducibly provide titanate ceramics for further characterization and testing. Plutonium-bearing pyrochlore-rich composites were consolidated to greater than 90% of their theoretical density.

  17. Influence of nanocrystalline phases on the electrical properties of lithium titanate phosphate glass ceramics mixed with Ga2O3 nanocrystals

    Microsoft Academic Search

    Ch. Krishna Kishore Reddy; Balaji Rao Ravuri; Ch. V. Koti Reddy; K. Veerabhadra Rao

    2011-01-01

    Several glass ceramic compositions dispersed with Ga2O3 nanocrystals, in the series samples (100???x)[0.4Li2O–0.1TiO2–0.5P2O5]?+?xGa2O3 with x?=?0, 2, 4, 6, 8, and 10?mol% of Ga2O3 were synthesized via high-energy ball milling technique and labeled as lithium gallium titanate phosphate glass (LTPGx) (x is the mol% of Ga2O3 nanocrystals). The compositions have been selected on the basis of thermal stability data obtained from

  18. Influence of nanocrystalline phases on the electrical properties of lithium titanate phosphate glass ceramics mixed with Ga2O3 nanocrystals

    Microsoft Academic Search

    Ch. Krishna Kishore Reddy; Balaji Rao Ravuri; Ch. V. Koti Reddy; K. Veerabhadra Rao

    2012-01-01

    Several glass ceramic compositions dispersed with Ga2O3 nanocrystals, in the series samples (100???x)[0.4Li2O–0.1TiO2–0.5P2O5]?+?xGa2O3 with x?=?0, 2, 4, 6, 8, and 10?mol% of Ga2O3 were synthesized via high-energy ball milling technique and labeled as lithium gallium titanate phosphate glass (LTPGx) (x is the mol% of Ga2O3 nanocrystals). The compositions have been selected on the basis of thermal stability data obtained from

  19. 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)

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

    2014-09-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Hall, D. A.; Mori, T.; Comyn, T. P.; Ringgaard, E.; Wright, J. P.

    2013-07-01

    High energy synchrotron XRD was employed to determine the lattice strain ?{111} and diffraction peak intensity ratio R{200} 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 ?{111}-cos2 ? plot, indicating a reduction in the level of residual stress due to poling. In contrast, the fraction of oriented 90° ferroelectric domains, quantified in terms of R{200}, 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.

  1. Crystal structure and related properties of copper-doped barium titanate ceramics

    NASA Astrophysics Data System (ADS)

    Langhammer, Hans Theo; Müller, Thomas; Böttcher, Rolf; Abicht, Hans-Peter

    2003-07-01

    The influence of copper on the crystallographic phase and the microstructure of ceramics with a nominal composition of BaTiO 3+0.02 BaO+ x CuO (0? x?0.02) was investigated. Systematic studies of X-ray diffraction and electron paramagnetic resonance (EPR) with varying doping level and sintering temperature were performed. The EPR data show that Cu 2+ is incorporated into the BaTiO 3 lattice at Ti-sites. Like in the case of other 3d transition elements as, e.g., Mn, Fe or Ni, also Cu decreases the phase transition temperature cubic-hexagonal and stabilizes the hexagonal phase at room temperature. At Cu concentrations ?0.3 mol% and at a sintering temperature of 1400 °C hexagonal phase occurs and the microstructure exhibits exaggerated, plate-like grains with grain sizes ?200 ?m which is typical for hexagonal BaTiO 3 ceramics. Compared to the doping with manganese, copper is more effective to stabilize the hexagonal phase, but its solubility into the BaTiO 3 lattice is significantly lower. Depending on doping level and sintering temperature the EPR data exhibit in the whole temperature range between 40 and 450 K a superposition of two spectra of Cu Ti2+ which are attributed to tetragonally distorted CuO 6 octahedra in a tetragonal and hexagonal crystal surrounding, respectively. Analogous to the case of Ti Ti3+ (d 1), Mn Ti3+ (d 4), Fe Ti2+ (d 6) or Ni Ti3+ (d 7), the Jahn-Teller distortion caused by the d 9 electron configuration of Cu Ti2+ is proposed as the driving force for the phase transition cubic to hexagonal.

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

    NASA Astrophysics Data System (ADS)

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

    2012-01-01

    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.

  3. Structural, electrical and electromechanical sensing properties of Bi-modified PLZT ceramics

    Microsoft Academic Search

    Soma Dutta; R. N. P. Choudhary; P. K. Sinha

    2004-01-01

    Piezoelectric ceramics lead zirconate titanate (PZT) is a material of high technological importance due to its applications in solid-state actuators, transducers and sensors. La+3 ion can be substituted for Pb+2 ion in PZT system (as called PLZT) because of its similar ionic sizes. The main aim of this work is to study the effect of trivalent Bi+3 doping on PLZT

  4. Effect of high density and reduced ionic defects on piezoelectric behavior of K0.5Na0.5NbO3 ceramic

    NASA Astrophysics Data System (ADS)

    Gupta, Shashaank; Priya, Shashank

    2015-01-01

    A reduced concentration of ionic defects along with >99 % of the theoretical density has been achieved for K0.5Na0.5NbO3 ceramic by employing a twofold sintering technique. Lower concentration of ionic defects resulted in an order of magnitude improvement in the resistivity and hence enhanced poling of the ceramic at 100 °C. High density and improved poling of the ceramic resulted in a significant improvement in electromechanical properties while maintaining the high orthorhombic-tetragonal ( T o-t) and Curie ( T c) temperatures of K0.5Na0.5NbO3 (200 and 395 °C respectively). A comparison with the previous studies suggested that the piezoelectric properties of the ceramic synthesized in this study were similar to those synthesized using complex techniques such as spark plasma sintering and hot pressing. This is a significant advancement facilitating the possibility of transition of K0.5Na0.5NbO3 ceramic toward device application.

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    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.

  6. Large-aperture optical modulator materials. Lead lanthanum zirconate titanate ceramic and lithium niobate crystal show promise as modulator materials for optical transmitters with up to 6-inch apertures

    Microsoft Academic Search

    R. P. Bocker; G. M. Meana; M. A. Monahan; G. C. Mooradian; W. E. Richards; H. F. Taylor

    1977-01-01

    Six categories of active optical materials were found to qualify as potential large-aperture optical modulator material candidates. Two of these, the electro-optical linear Pockels lithium niobate crystals and the ferroelectric ceramic lead lanthanum zirconate titanate wafers showed real promise. Both of these satisfy the requirements of field of view, optical quality, frequency response, and economic availability, and both performed above

  7. Enhanced active piezoelectric 0-3 nanocomposites fabricated through electrospun nanowires

    NASA Astrophysics Data System (ADS)

    Feenstra, Joel; Sodano, Henry A.

    2008-06-01

    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 (BaTiO3) sol gel to produce fibers with 500-1000nm diameters and subsequently calcinated to acquire perovskite BaTiO3. 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.

  8. Preparation and characterization of Mn-doped Li0.06(Na0.5K0.5)0.94NbO3 lead-free piezoelectric ceramics with surface sol-gel coatings

    NASA Astrophysics Data System (ADS)

    Yoo, Ae Ri; Lee, Seong Eui; Lee, Hee Chul

    2014-08-01

    This study investigated the effects of Mn doping and sol-gel surface coating on the structural and the electrical properties of lead-free Li0.06(Na0.5K0.5)0.94NbO3(LNKN) ceramics in disc form for use as eco-friendly piezoelectric devices. The 1-mol% Mn-doped LNKN ceramic showed a relatively high piezoelectric constant owing to its high density in the case of its being annealed at a temperature of 1010 °C. A Mn-doped LNKN sol-gel solution with the same composition as that of the ceramics was spin-coated and sintered on both sides of the ceramic surfaces to acquire improved electrical properties. The sol-gel surface coating could play a decisive role in filling the pores, resulting in flat and stable interfaces between the electrodes and the piezoelectric elements. As a result, the highest piezoelectric constant, d33, of 173 pC/N could be obtained for the Mn-doped LNKN ceramics with 420-nm-thick sol-gel surface coatings.

  9. Reactive sintering of (K0.5Bi0.5)TiO3-BiFeO3 lead-free piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Fisher, John G.; Kim, Min-Gu; Kim, Daeung; Cha, Su-Jeong; Vu, Hung Van; Nguyen, Dieu; Kim, Young-Hun; Moon, Su-Hyun; Lee, Jong-Sook; Hussain, Ali; Kim, Myong-Ho

    2015-05-01

    Ceramics based on BiFeO3 are potential lead-free replacements for Pb(Zr,Ti)O3 in a variety of applications such as sensors, transducers and actuators. Recently, ceramics in the (K0.5Bi0.5)TiO3-BiFeO3 system were developed which have excellent piezoelectric properties. However, these ceramics are difficult to sinter to high density. The present work studies the use of reactive sintering to prepare 0.4(K0.5Bi0.5)TiO3-0.6BiFeO3 ceramics. Undoped and MnO-doped powders were prepared by ball milling K2CO3, (BiO)2CO3, TiO2, ?-FeO(OH) and MnCO3 in ethanol with zirconia milling media. The decomposition and calcination reactions of the starting materials were studied using differential scanning calorimetry/thermogravimetric analysis, X-ray diffraction and Fourier transform infra-red analysis. Samples were sintered in the temperature range from 1000 to 1075°C and their structures and microstructures examined using X-ray diffraction, micro-Raman scattering and scanning electron microscopy. MnO doping reduced the rhombohedral distortion of the unit cell. The dielectric, ferroelectric and piezoelectric properties of selected undoped and MnO-doped samples were measured. Both undoped and MnO-doped samples displayed relaxor-type behavior. MnO doping reduced the conductivity of the samples, which exhibit a well-defined activation energy of 1.21 eV. Undoped samples have strain vs. electric field properties comparable to those reported in the literature.

  10. Dielectric, piezoelectric, and ferroelectric properties of grain-orientated Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12} ceramics

    SciTech Connect

    Liu Jing; Shen Zhijian; Yan Haixue; Reece, Michael J.; Kan Yanmei; Wang Peiling [Department of Inorganic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm (Sweden); Department of Materials, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Shanghai Institute of Ceramics, Chinese Academy of Science, 1295 Dingxi Road, Shanghai 200050 (China)

    2007-11-15

    By dynamic forging during Spark Plasma Sintering (SPS), grain-orientated ferroelectric Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12} (BLT) ceramics were prepared. Their ferroelectric, piezoelectric, and dielectric properties are anisotropic. The textured ceramics parallel and perpendicular to the shear flow directions have similar thermal depoling behaviors. The d{sub 33} piezoelectric coefficient of BLT ceramics gradually reduces up to 350 deg. C; it then drops rapidly. The broadness of the dielectric constant and loss peaks and the existence of d{sub 33} above the permittivity peak, T{sub m}, show that the BLT ceramic has relaxor-like behavior.

  11. Piezoelectric and ferroelectric properties of Cu-doped K0.5Na0.5NbO3 lead-free ceramics

    NASA Astrophysics Data System (ADS)

    Lin, Dunmin; Kwok, K. W.; Chan, H. L. W.

    2008-02-01

    CuO-doped K0.5Na0.5NbO3 (K0.5Na0.5NbO3 + x mol% CuO) lead-free ceramics have been prepared by an ordinary sintering technique. The results of x-ray diffraction patterns show that all the ceramics possess a pure pervoskite structure with orthorhombic symmetry. Based on the symmetry-conforming principle of point defects, defect dipoles are formed by the acceptor dopant ions Cu2+ and O2- vacancies along the polarization direction and remain in the original orientation, providing a restoring force to reverse the switched polarization, which results in double polarization-electric hysteresis loops for the ceramics with x >= 0.50 at 100 Hz. That is, the ferroelectric dipoles are back to their original orientation on the removal of electric field due to the strong restoring force generated by defect dipoles. As a result, the ceramics (x >= 0.5) become considerably 'hardened' and possess an extraordinarily high Qm (825-2523) and simultaneously the other piezoelectric properties remain reasonably good (kp = 39%, kt = 47% and d33 = 82 pC N-1).

  12. Comparison of actuator properties for piezoelectric and electrostrictive materials

    NASA Astrophysics Data System (ADS)

    Pan, Ming-Jen; Rehrig, Paul W.; Kucera, John P.; Park, Seung Eek E.; Hackenberger, Wesley S.

    2000-06-01

    The field induced strain has been measured for a broad variety of piezoelectric and electrostrictive actuator materials. These measurements have been made under AC drive conditions with variations in DC bias, peak to peak voltage, and prestress. Data for three types of PMN-PT electrostrictors, hard and soft piezoelectric ceramics, and PZN-PT single crystal have been collected. For smart structures applications fine grain Type II ceramic and PZN- PT single crystals were found to have the best combination of moderate to high strain, low to moderate hysteresis, and resistance to stress depoling. Electrostrictive ceramics used for high frequency transducers were found to exhibit some stress induced domain reorientation effects that depended on drive conditions and operating temperature. These effects became more pronounced for electrostrictors with high lead titanate content. Epoxy bonded stacks have been constructed form some of the materials to determine the merits of materials properties for actuator performance. This work has shown that fine grain Type II ceramics have many advantages for high authority stack actuators including high strain energy density and lifetimes > 109 cycles at 100 percent rated peak-to-peak voltage.

  13. Microstructure and Electrical Properties of K0.5Na0.5NbO3-LiSbO3-BiFeO3- x %molZnO Lead-Free Piezoelectric Ceramics

    NASA Astrophysics Data System (ADS)

    Zhao, Xiayan; Wang, Hua; Xu, Jiwen; Yuan, Changlai; Zhai, Xia; Cui, Yerang

    2014-02-01

    Lead-free piezoelectric ceramics {0.996[(0.95(K0.5Na0.5)NbO3-0.05LiSbO3]-0.004BiFeO3}- xmol%ZnO were prepared through a conventional ceramics sintering technique. The effect of ZnO content on structure, microstructure, and piezoelectric properties of KNN-LS-BF ceramics was investigated. The results reveal that ZnO as a sintering aid is very effective in promoting sinterability and electrical properties of the ceramics sintered at a low temperature of 1,020 °C. The ceramics show a single-perovskite structure with predominant tetragonal phase, and coexistence of orthorhombic and tetragonal phases is observed for x = 2.5-3.0. The addition of ZnO causes abnormal grain growth. A dense microstructure is also obtained at x = 2.0 because the relative density reaches up to 94.6 %. The morphotropic phase boundary and dense microstructure lead to significant enhancement of the piezoelectric properties. The ceramic with x = 1.5 exhibits optimum electrical properties as follows: d 33 = 280 pC/N, k p = 46 %, Q m = 40.8, P r = 25 ?C/cm2, E c = 1.2 kV/mm, and T c = 340 °C.

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    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.

  15. Effects of Polarization on Mechanical Properties of Lead Zirconate Titanate Ceramics Evaluated by Modified Small Punch Tests

    NASA Astrophysics Data System (ADS)

    Deng, Qihuang; Fan, Yuchi; Wang, Lianjun; Xiong, Zhi; Wang, Hongzhi; Li, Yaogang; Zhang, Qinghong; Kawasaki, Akira; Jiang, Wan

    2012-01-01

    Pb(Zr,Ti)O3 (PZT) ceramics were prepared by the conventional mixed oxide method, and the strength of the resultant PZT ceramics was evaluated using modified small punch (MSP) tests. Load-displacement curve test results showed that the crack-initiation and fracture strengths of PZT ceramics decreased after polarization. The effect of the polarization accelerated the fatigue properties of PZT ceramics. Scanning electron microscopy (SEM) results showed that microcracks were formed before the maximum load in the MSP test, and the first load drop corresponded to crack initiation.

  16. Additive effects on electrical properties of (Bi 1\\/2Na 1\\/2)TiO 3 ferroelectric ceramics

    Microsoft Academic Search

    Hajime Nagata; Tadashi Takenaka

    2001-01-01

    Microstructure, dielectric, ferroelectric and piezoelectric properties of bismuth sodium titanate (Bi1\\/2Na1\\/2)TiO3 (BNT) were studied for a candidate as lead-free piezoelectric ceramics. In the case of Mn addition, the Curie temperature, Tc, decreases rapidly with increasing amount of doped MnCO3. The resistivity, ?, is enhanced to 3×1014 (?cm) (at 40°C) for BNT+MnCO3 0.2 (wt.%) and electromechanical coupling factor, k33, was obtained

  17. Fabrication and Characterization of (100),(001)-Oriented Reduction-Resistant Lead-Free Piezoelectric (Ba,Ca)TiO3 Ceramics Using Platelike Seed Crystals

    NASA Astrophysics Data System (ADS)

    Ichikawa, Hiroki; Sakamoto, Wataru; Akiyama, Yoshikazu; Maiwa, Hiroshi; Moriya, Makoto; Yogo, Toshinobu

    2013-09-01

    The preparation of reduction-resistant (Ba,Ca)TiO3 ceramics as lead-free piezoelectric materials was studied. To improve their electrical properties, (100),(001)-oriented (Ba0.85Ca0.15)TiO3 ceramics were fabricated by the reactive templated grain growth method using a mixture of platelike CaTiO3 and BaTiO3 particles. The platelike CaTiO3 and BaTiO3 particles were prepared through a topochemical microcrystal conversion process using CaBi4Ti4O15 and BaBi4Ti4O15 plate-like precursor crystals. The 100 orientation degree of the grain-oriented (Ba0.85Ca0.15)TiO3 ceramics was 92%, as estimated by Lotgering's equation. In addition, 1 mol % Ba excess and 1 mol % Mn-doped (Ba0.85Ca0.15)TiO3 sintered bodies, which were sintered at 1350 °C in an Ar flow containing H2 (0.3%), had sufficient resistivity to allow the characterization of electrical properties. The ferroelectric and field-induced strain properties of the (Ba0.85Ca0.15)TiO3 ceramics, sintered in the reducing atmosphere, were markedly improved as a result of fabricating grain-oriented samples. The field-induced strain coefficient (estimated from the slope of the unipolar strain loop) of the nonreducible (100),(001)-oriented (Ba0.85Ca0.15)TiO3 ceramics reached 570 pm/V, which was higher than that of polycrystals (260 pm/V) with no preferential orientation.

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

    Microsoft Academic Search

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

    2009-01-01

    (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

  19. Effects of sintering aid CuTa{sub 2}O{sub 6} on piezoelectric and dielectric properties of sodium potassium niobate ceramics

    SciTech Connect

    Yang, Song-Ling [Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan, ROC (China)] [Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan, ROC (China); Tsai, Cheng-Che [Department of Electronics Engineering and Computer Science, Tung-Fang Design University, Kaohsiung 82941, Taiwan, ROC (China)] [Department of Electronics Engineering and Computer Science, Tung-Fang Design University, Kaohsiung 82941, Taiwan, ROC (China); Hong, Cheng-Shong [Department of Electronic Engineering, National Kaohsiung Normal University, Kaohsiung County 824, Taiwan, ROC (China)] [Department of Electronic Engineering, National Kaohsiung Normal University, Kaohsiung County 824, Taiwan, ROC (China); Chu, Sheng-Yuan, E-mail: chusy@mail.ncku.edu.tw [Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan, ROC (China) [Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan, ROC (China); Center for Micro/Nano Science and Technology and Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan, ROC (China)

    2012-04-15

    Graphical abstract: NKN ceramics with a sintering aid CuTa{sub 2}O{sub 6} (CT) doping increased the mechanical quality factor (Q{sub m}) and electromechanical coupling factor (k{sub p}). Highlights: Black-Right-Pointing-Pointer A new sintering aid CuTa{sub 2}O{sub 6} was developed to dope into NKN ceramics. Black-Right-Pointing-Pointer Dense NKN ceramics were obtained as CuTa{sub 2}O{sub 6} compound doping. Black-Right-Pointing-Pointer We find the soluble limit of CuTa{sub 2}O{sub 6} compound incorporated into NKN ceramics. Black-Right-Pointing-Pointer The maximum Q{sub m} and k{sub p} values were more than 1500 and 42%, respectively. Black-Right-Pointing-Pointer CuTa{sub 2}O{sub 6} compound is a better sintering aid compared with K{sub 5.3}Cu{sub 1.3}Ta{sub 10}O{sub 29}. -- Abstract: In this study, the effects of a sintering aid CuTa{sub 2}O{sub 6} (CT) on (Na{sub 0.5}K{sub 0.5})NbO{sub 3} (NKN) ceramics were investigated. The diffracted angles in XRD profiles decreased because the Nb-sites were replaced by Cu and Ta ions, causing the expansion of lattice volume. SEM images showed smaller grain sizes at a low concentration of CuTa{sub 2}O{sub 6}, and grain sizes increased as the concentration of CuTa{sub 2}O{sub 6} doping increased because of a liquid phase formed. When CuTa{sub 2}O{sub 6} dopants were doped into NKN ceramics, the T{sub O-T} and T{sub c} phase transitions decreased because the replacement of Ta{sup 5+} ions in the B-site. A high bulk density (4.595 g/cm{sup 3}) and electromechanical coupling factor (k{sub p}, k{sub t}) were enhanced when CT dopants were doped into NKN ceramics. Moreover, the mechanical quality factor (Q{sub m}) also increased from 67 to 1550. NKN ceramics with sintering aid CuTa{sub 2}O{sub 6} doping showed excellent piezoelectric properties: k{sub p}: 42.5%; k{sub t}: 49.1%; Q{sub m}: 1550; and d{sub 33}: 96 pC/N.

  20. Mechanical and dielectric characterization of lead zirconate titanate(PZT)/polyurethane(PU) thin film composite for energy harvesting

    NASA Astrophysics Data System (ADS)

    Aboubakr, S.; Rguiti, M.; Hajjaji, A.; Eddiai, A.; Courtois, C.; d'Astorg, S.

    2014-04-01

    The Lead Zirconate titanate (PZT) ceramic is known by its piezoelectric feature, but also by its stiffness, the use of a composite based on a polyurethane (PU) matrix charged by a piezoelectric material, enable to generate a large deformation of the material, therefore harvesting more energy. This new material will provide a competitive alternative and low cost manufacturing technology of autonomous systems (smart clothes, car seat, boat sail, flag ...). A thin film of the PZT/PU composite was prepared using up to 80 vol. % of ceramic. Due to the dielectric nature of the PZT, inclusions of this one in a PU matrix raises the permittivity of the composite, on other hand this latter seems to decline at high frequencies.

  1. Microstructural variations and their influence on the performance of solid oxide fuel cells based on yttrium-substituted strontium titanate ceramic anodes

    NASA Astrophysics Data System (ADS)

    Ma, Qianli; Iwanschitz, Boris; Dashjav, Enkhtsetseg; Baumann, Stefan; Sebold, Doris; Arul Raj, Irudayam; Mai, Andreas; Tietz, Frank

    2015-04-01

    Donor-substituted strontium titanates have been widely recognised as alternative anode materials to the state-of-the-art Ni/YSZ cermets in solid oxide fuel cells (SOFCs). Electrolyte-supported SOFCs based on Y0.07Sr0.895TiO3 ceramic anodes with different microstructural designs were prepared. Ni or Ni with Ce0.8Gd0.2O1.9 (CGO) was infiltrated onto the pore walls within the ceramic anode framework as an electrocatalyst for anode reactions. Performances and electrochemical impedance spectroscopy measurements of the cells were analysed in detail to observe the influence of low ionic conductivity of Y0.07Sr0.895TiO3 to cell performance, to understand how to control the degradation of the cells, and to obtain a possible mechanism for the anode processes. The anode design containing both functional and current collecting layers with sufficient Ni-CGO infiltration is favourable for high power output and low performance degradation.

  2. Influence of combined external stress and electric field on electric properties of 0.5% Fe-doped lead zirconate titanate ceramics

    NASA Astrophysics Data System (ADS)

    Suchanicz, J.; Kim-Ngan, N.-T. H.; Konieczny, K.; Jankowska-Sumara, I.; Sitko, D.; Goc-Jaglo, D.; Balogh, A. G.

    2009-11-01

    Influence of uniaxial pressure (0-1000 bars) applied parallel to or perpendicularly to the ac or dc electric field (in one-dimensional or two-dimensional manner) on dielectric and ferroelectric properties of hard lead zirconate titanate (PZT) ceramics were investigated. The experimental results revealed that applying uniaxial pressure leads to a reduction in the peak intensity of the electric permittivity (?), of the frequency dispersion as well as of the dielectric hysteresis. Moreover, with increasing pressure the peak intensity of ? becomes diffused and shifts to a higher temperature. It was also found that simultaneous application of uniaxial pressure and electric field (perpendicular to each other) in the poling process improves the ferroelectric properties. This indeed indicates new possibility for poling materials with a high coercive field and/or high electric conductivity. The effects of uniaxial load are weaker than that obtained for soft PZT ceramics. It was concluded that applying uniaxial pressure induces similar effects as increasing the Ti ion concentration in PZT system. The obtained results were interpreted through Cochran soft mode and domain switching processes under applying of pressure.

  3. Characterisation of a PdCl 2/SnCl 2 electroless plating catalyst system adsorbed on barium titanate-based electroactive ceramics

    NASA Astrophysics Data System (ADS)

    Meenan, B. J.; Brown, N. M. D.; Wilson, J. W.

    1994-03-01

    A PdCl 2/SnCl 2 metallisation catalyst system, of the type used to activate non-conducting surfaces for electroless metal deposition, has been characterised by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The substrate is a barium titanate (BaTiO 3)-based electroactive ceramic of the type used in the fabrication of multilayer ceramic capacitors (MLCC). The treatment of the substrate surface with the PdCl 2/SnCl 2 "sensitiser" solution leads to the adsorption of catalytically inactive compounds of palladium and tin. Subsequent treatment of this surface with an "accelerator" solution removes excess oxides, hydroxides and salts of tin thereby leaving the active catalyst species, Pd xSn y, on the surface. Such sites, on exposure to the appropriete electroless plating bath, are then responsible for the metal deposition. In this study, the chemical state and relative quantities of the various surface species present after each of the processing stages have been determined by XPS. The surface roughness of the substrate results in less of the tin compounds present thereon being removed on washing the catalysed surface in the accelerator solution than normally reported for such systems, thereby affecting the measured Pd: Sn ratio. SEM studies show that the accelerator solution treatment generates crystalline areas, which may be a result of coagulation of the Pd xSn y particles present, in the otherwise amorphous catalyst coating.

  4. Light-intensity-induced characterization of elastic constants and d33 piezoelectric coefficient of PLZT single fiber based transducers.

    PubMed

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

    2013-01-01

    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 d(33). PMID:23403643

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

    PubMed Central

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

    2013-01-01

    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

  6. Received 8 Mar 2014 | Accepted 24 Jun 2014 | Published 5 Aug 2014 Conformable amplified lead zirconate titanate

    E-print Network

    Rogers, John A.

    lead zirconate titanate sensors with enhanced piezoelectric response for cutaneous pressure monitoring studies reveal enhanced piezoelectric responses in lead zirconate titanate that follow from integration co-integration of other types of active materials and classes of components. Lead zirconate titanate

  7. Polymorphic phase transition and piezoelectric properties of (Ba 1- xCa x)(Ti 0.9Zr 0.1)O 3 lead-free ceramics

    NASA Astrophysics Data System (ADS)

    Li, Wei; Xu, Zhijun; Chu, Ruiqing; Fu, Peng; Zang, Guozhong

    2010-11-01

    Lead-free (Ba 1- xCa x)(Ti 0.9Zr 0.1)O 3 ( x=0.12-0.18) (BCZT) ceramics were prepared successfully using a solid-state reaction technique. The polymorphic phase transitions (PPT) from rhombohedral to orthorhombic phase around room temperature were identified in the composition range 0.14< x<0.18. The samples at x=0.16, showing coexistence of rhombohedral and orthorhombic phase, exhibit enhanced piezoelectric and dielectric properties of d33=328 pC/N, kp=37.6% and ??=4800. With the increase of Ca content, the polymorphic phase transitions shift to lower temperature and cannot be observed above room temperature at x?0.18.

  8. Ferroelectric and piezoelectric properties of tungsten substituted SrBi{sub 2}Ta{sub 2}O{sub 9} ferroelectric ceramics

    SciTech Connect

    Coondoo, Indrani, E-mail: indrani_coondoo@yahoo.com; Agarwal, S.K. [Superconductivity and Cryogenics Division, National Physical Laboratory, Dr K.S. Krishnan Road, New Delhi 110012 (India); Jha, A.K. [Department of Applied Physics, Delhi College of Engineering, Bawana Road, Delhi 110042 (India)

    2009-06-03

    Tungsten substituted samples of compositions SrBi{sub 2}(W{sub x}Ta{sub 1-x}){sub 2}O{sub 9} (x = 0.0, 0.025, 0.050, 0.075, 0.10 and 0.20) were synthesized by solid-state reaction method and studied for their microstructural, electrical conductivity, ferroelectric and piezoelectric properties. The X-ray diffractograms confirm the formation of single phase layered perovskite structure in the samples with x up to 0.05. The temperature dependence of dc conductivity vis-a-vis tungsten content shows a decrease in conductivity, which is attributed to the suppression of oxygen vacancies. The ferroelectric and piezoelectric studies of the W-substituted SBT ceramics show that the remanent polarization and d{sub 33} values increases with increasing concentration of tungsten up to x {<=} 0.05. Such compositions with low conductivity and high P{sub r} values should be excellent materials for highly stable ferroelectric memory devices.

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

    PubMed

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

    2015-03-11

    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

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

    E-print Network

    Smyth, Katherine Marie

    2012-01-01

    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 ...

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

    E-print Network

    Cao, Wenwu

    Dielectric and piezoelectric properties of sodium lithium niobate Na1-xLixNbO3 lead free # Springer Science + Business Media, LLC 2007 Abstract High density sodium lithium niobate lead free ce-to-paraelectric phase transition (tetragonal) takes place at about 354 °C (Curie temperature). Lithium Niobate LiNbO3

  12. Structure and electrical properties of (Bi1/2Na1/2)0.94-x(Li1/2Ce1/2)xBa0.06TiO3 lead-free piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Cheng, Renfei; Yang, Zhenjie; Xu, Zhijun; Chu, Ruiqing; Hao, Jigong; Du, Juan; Li, Guorong

    2015-06-01

    Lead-free piezoelectric ceramics BNT-BT6-LCx has been successfully synthesized by the conventional solid-state reaction method. All BNT-BT6-LCx ceramics form the pure perovskite phase structure, and no obvious change in the crystal structure is observed with the addition of (Li1/2Ce1/2). Transition temperature Tm is found to be no obvious change and Td decreases continuously with x. Composition with x=0.010 has shown the optimum ferroelectric and piezoelectric properties with low value of Ec, which are as follows: Pr=32.65 ?C/cm2, Ec=41 kV/cm and d33=163 pC/N.

  13. Ceramics

    NASA Astrophysics Data System (ADS)

    Yao, Lichun; Yang, Jian; Qiu, Tai

    2014-09-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    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.

  15. Ferroelectric, dielectric and piezoelectric properties of Sr{sub 0.6}(BiNa){sub 0.2}Bi{sub 2}Nb{sub 2}O{sub 9} ceramics

    SciTech Connect

    Fang, Pinyang, E-mail: fpy_2000@163.com; Xi, Zengzhe; Long, Wei; Li, Xiaojuan

    2013-11-15

    Graphical abstract: The oxygen vacancy was confirmed by the left figure and the role of oxygen vacancy on the piezoelectric properties was discussed. - Highlights: • The d{sub 33}, ? and T{sub c} were found to be 22 pC/N, ? ? 10{sup 6} ? cm and 586 °C. • The electromechanical properties: k{sub p} ? 5.0%, k{sub t} ? 8.7% and Q{sub m} ? 651. • The oxygen vacancy is responsible for electrical properties at high temperature. - Abstract: Aurivillius-type ceramic, Sr{sub 0.6}(BiNa){sub 0.2}Bi{sub 2}Nb{sub 2}O{sub 9} (SBNBN), was synthesized by using conventional solid-state processing. Phase structure and microstructural morphology were confirmed by X-ray diffraction analyses (XRD) and the scanning electron microscopy (SEM). Dielectric, piezoelectric and electromechanical properties of the SBNBN ceramic were investigated in detail. Curie temperature (T{sub c}), piezoelectric coefficient (d{sub 33}), electromechanical coupling coefficient k{sub p}, k{sub t} and quality factor Q{sub m} of the SBNBN ceramic were found to be 586.5 °C, 22 pC/N, 5.0%, 8.7% and 651, respectively. In addition, the reasons for varieties of the resistivity and dielectric properties at high temperature were also discussed.

  16. PHASE TRANSITION, DIELECTRIC AND PIEZOELECTRIC PROPERTIES OF NaNbO3-Ba0.85Ca0.15(Ti0.9Zr0.1)O3 LEAD-FREE CERAMICS

    NASA Astrophysics Data System (ADS)

    Lei, Yuqing; Wu, Hong; Lin, Dunmin; Zheng, Qiaoji; Wu, Xiaochun; Fan, Ximing

    2012-09-01

    A new lead-free solid solution of (1-x)NaNbO3-xBa0.85Ca0.15(Ti0.9Zr0.1)O3 was prepared by a traditional sintering method and its phase transition, dielectric and piezoelectric properties were studied. Ba0.85Ca0.15(Ti0.9Zr0.1)O3 diffuses into NaNbO3 lattices to form a new solid solution with perovskite structure. The addition of Ba0.85Ca0.15(Ti0.9Zr0.1)O3(x?0.025) transforms NaNbO3 from antiferroelectric to ferroelectric. The diffusive ferroelectric-paraelectric phase transition is induced in the ceramics with high concentration of Ba0.85Ca0.15(Ti0.9Zr0.1)O3. The ceramics with x = 0.05-0.125 possess large Pr values of 18.6-25.5 ?C/cm2. A morphotropic phase boundary between tetragonal and orthorhombic phases is formed at 0.05 < x < 0.15, leading to a significant enhancement of piezoelectric properties. The ceramic with x = 0.125 situated near the morphotropic phase boundary exhibits the optimum piezoelectric properties: d33 = 151 pC/N and kp = 31.6%.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    (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.

  18. Pyrochlore-rich titanate ceramics for the immobilization of plutonium: redox effects on phase equilibria in cerium- and thorium- substituted analogs

    SciTech Connect

    Ryerson, F J; Ebbinghaus, B

    2000-05-25

    Three compositions representing plutonium-free analogs of a proposed Ca-Ti-Gd-Hf-U-PU oxide ceramic for the immobilization of plutonium were equilibrated at 1 atm, 1350 C over a range of oxygen fugacities between air and that equivalent to the iron-wuestite buffer. The cerium analog replaces Pu on a mole-per-mole basic with Ce; the thorium analog replaces Pu with Th. A third material has 10 wt% Al{sub 2}O{sub 3} added to the cerium analog to encourage the formation of a Hf-analog of, CaHfTi{sub 2}O{sub 7}, zirconolite, which is referred to as hafnolite. The predominant phase produced in each formulation under all conditions is pyrochlore, A{sub 2}T{sub 2}O{sub 7}, where the T site is filled by Ti, and Ca, the lanthanides, Hf, U and Pu are accommodated on the A-site. Other lanthanide and uranium-bearing phases encountered include brannerite (UTi{sub 2}O{sub 6}), hafnolite (CaHfTi{sub 2}O{sub 7}), perovskite (CaTiO{sub 3}) and a calcium-lanthanide aluminotitanate with nominal stoichiometry (Ca,Ln)Ti{sub 2}Al{sub 9}O{sub 19}, where Ln is a lanthanide. The phase compositions show progressive shifts with decreasing oxygen fugacity. All of the phases observed have previously been identified in titanate-based high-level radioactive waste ceramics and demonstrate the flexibility of these ceramics to variations in processing parameters. The main variation is an increase in the uranium concentrations of pyrochlore and brannerite which must be accommodated by variations in modal abundance. Pyrochlore compositions are consistent with existing spectroscopic data suggesting that uranium is predominantly pentavalent in samples synthesized in air. A simple model based on ideal stoichiometry suggests the U{sup +4}/{Sigma}U varies linearly with log fO{sub 2} and that all of the uranium is quadravalent at the iron-wuestite buffer.

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

    SciTech Connect

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

    2007-10-15

    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.

  20. ceramics

    NASA Astrophysics Data System (ADS)

    Liu, G.; Liu, X. Q.; Chen, X. M.

    2014-09-01

    The dielectric properties of Sm1.5Sr0.5NiO4- ? ceramics with different concentrations of oxygen vacancies were characterized. The ceramics with lower concentration of oxygen vacancies were prepared by directly sintering the sol-gel derived powders in air, while the higher one could be obtained by annealing the as-sintered ceramics in the flow of nitrogen. The post-densification annealing in the flow of nitrogen decreased the dielectric constant at low temperature and increased it at high temperature, while the dielectric loss increased in overall temperature range. The activation energy of low-temperature dielectric relaxation decreased with increasing the concentration of oxygen vacancies, and so did that of bulk electrical resistances although the values of resistances increased, while the activation energy of electrical resistances for grain boundary increased though the values of resistances decreased. The giant dielectric response in the as-sintered Sm1.5Sr0.5NiO4- ? ceramics should be mainly attributed to the small polaronic hopping process, while that of annealed ceramics should be directly linked to the oxygen vacancies.

  1. Active Piezoelectric Diaphragms

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  2. Piezoelectric properties of nonstoichiometric Sr{sub 1-x}Bi{sub 2+2x/3}Ta{sub 2}O{sub 9} ceramics

    SciTech Connect

    Jain, Rajni; Chauhan, Arun Kumar Singh; Gupta, Vinay; Sreenivas, K. [Department of Physics and Astrophysics, University of Delhi, Delhi-110007 (India)

    2005-06-15

    The effect of poling on the structural, dielectric, and piezoelectric properties has been investigated for sol-gel-derived strontium bismuth tantalate (SBT) [Sr{sub 1-x}Bi{sub 2+2x/3}Ta{sub 2}O{sub 9}] ceramics with x=0.0,0.15,0.30,0.45. The dielectric and ferroelectric properties are found to improve with increase in x up to 0.3. Beyond x>0.3 the properties are found to degrade due to the limited solid solubility and the presence of a mixed phase of bismuth tantalate (BiTaO{sub 4}) is detected with x=0.45. Poling treatment reduces the dielectric dispersion and dielectric loss in the frequency range (0.1-100 kHz). The resonance and antiresonance frequencies increase with increase in x (x=0-0.30), and the corresponding minimum impedance decreases. The measured coupling coefficients (k{sub p}) are small (0.0967-0.1) for x=0-0.30, and the electromechanical quality factor (Q{sub m}=915) is a maximum for the Sr{sub 0.7}Bi{sub 2.2}Ta{sub 2}O{sub 9} composition (x=0.30). The estimated piezoelectric charge coefficient (d{sub 31}) and piezoelectric voltage coefficient (g{sub 31}) are 5.2 pC/N and 5.8x10{sup -3} V m/N, respectively. The positive values of d{sub 31} and g{sub 31} and the low dielectric permittivity of SBT yield a high value for the hydrostatic coefficients, despite the low charge coefficient of d{sub 33}=24 pC/N. The maximum values of charge coefficient (d{sub h}=34 pC/N) and voltage coefficient (g{sub h}=39x10{sup -3} V m/N) are obtained for Sr{sub 0.7}Bi{sub 2.2}Ta{sub 2}O{sub 9} composition, and the estimated hydrostatic figure of merit (d{sub h}g{sub h}x10{sup -15}=1215 m{sup 2}/N) is high.

  3. A micromachining process for die-scale pattern transfer in ceramics and its application to bulk piezoelectric actuators

    Microsoft Academic Search

    Tao Li; Yogesh B. Gianchandani

    2006-01-01

    This paper reports on a batch mode planar pattern transfer process for bulk ceramics, glass, and other hard, brittle, nonconductive materials suitable for micromachined transducers and packages. The process is named LEEDUS, as it combines lithography, electroplating, batch mode micro electro-discharge machining (?EDM) and batch mode micro ultrasonic machining (?USM). An electroplating mold is first created on a silicon or

  4. Superior piezoelectric composite films: taking advantage of carbon nanomaterials.

    PubMed

    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

    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

  5. Superior piezoelectric composite films: taking advantage of carbon nanomaterials

    NASA Astrophysics Data System (ADS)

    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

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    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.

  7. Titan Meteorology

    NASA Astrophysics Data System (ADS)

    Mitchell, Jonathan

    2012-04-01

    Titan’s methane clouds have received much attention since they were first discovered spectroscopically (Griffith et al. 1998). Titan's seasons evolve slowly, and there is growing evidence of a seasonal response in the regions of methane cloud formation (e.g. Rodriguez et al. 2009). A complete, three-dimensional view of Titan’s clouds is possible through the determination of cloud-top heights from Cassini images (e.g., Ádámkovics et al. 2010). Even though Titan’s surface is warmed by very little sunlight, we now know Titan’s methane clouds are convective, evolving through tens of kilometers of altitude on timescales of hours to days with dynamics similar to clouds that appear on Earth (Porco et al. 2005). Cassini ISS has also shown evidence of rain storms on Titan that produce surface accumulation of methane (Turtle et al. 2009). Most recently, Cassini has revealed a 1000-km-scale, arrow-shaped cloud at the equator followed by changes that appear to be evidence of surface precipitation (Turtle et al. 2011b). Individual convective towers simulated with high fidelity indicate that surface convergence of methane humidity and dynamic lifting are required to trigger deep, precipitating convection (e.g. Barth & Rafkin 2010). The global expanses of these cloud outbursts, the evidence for surface precipitation, and the requirement of dynamic convergence and lifting at the surface to trigger deep convection motivate an analysis of storm formation in the context of Titan’s global circulation. I will review our current understanding of Titan’s methane meteorology using Cassini and ground-based observations and, in particular, global circulation model simulations of Titan’s methane cycle. When compared with cloud observations, our simulations indicate an essential role for planetary-scale atmospheric waves in organizing convective storms on large scales (Mitchell et al. 2011). I will end with predictions of Titan’s weather during the upcoming northern hemisphere summer.

  8. Energy Harvesting Devices Utilizing Resonance Vibration of Piezoelectric Buzzer

    NASA Astrophysics Data System (ADS)

    Ogawa, Toshio; Sugisawa, Ryosuke; Sakurada, Yuta; Aoshima, Hiroshi; Hikida, Masahito; Akaishi, Hiroshi

    2013-09-01

    A piezoelectric buzzer for energy harvesting was investigated. Although an external force was added to a buzzer, a lead zirconate titanate (PZT) unimorph in the buzzer, the ceramic disc diameter, thickness, and capacitance of which were respectively 14 mm, 0.2 mm, and 10 nF, generated resonance vibration. As a result, alternating voltages of around 30 V and a frequency of 5 kHz were observed. When the generated voltages were applied to a LED lamp, new devices such as a “night-view footwear” and a “piezo-walker” were developed. It was confirmed that the piezo-buzzer for energy harvesting utilizing resonance vibration is an effective tool for obtaining clean energy.

  9. Array lead zirconate titanate/glass piezoelectric microcantilevers for real-time detection of Bacillus anthracis with 10 spores/ml sensitivity and 1/1000 selectivity in bacterial mixtures

    NASA Astrophysics Data System (ADS)

    McGovern, John-Paul; Shih, Wei-Heng; Rest, Richard F.; Purohit, Mitali; Mattiucci, Mark; Pourrezaei, Kambiz; Onaral, Banu; Shih, Wan Y.

    2009-12-01

    An array of three identical piezoelectric microcantilever sensors (PEMSs) consisting of a lead zirconate titanate layer bonded to a glass layer was fabricated and examined for simultaneous, in situ, real-time, all-electrical detection of Bacillus anthracis (BA) spores in an aqueous suspension using the first longitudinal extension mode of resonance. With anti-BA antibody immobilized on the sensor surfaces all three PEMS exhibited identical BA detection resonance frequency shifts at all tested concentrations, 10-107 spores/ml with a standard deviation of less than 10%. The detection concentration limit of 10 spores/ml was about two orders of magnitude lower than would be permitted by flexural peaks. In blinded-sample testing, the array PEMS detected BA in three samples containing BA: (1) 3.3×103 spores/ml, (2) a mixture of 3.3×103 spores/ml and 3.3×105 S. aureus (SA) and P. aeruginosa (PA) per ml, and (3) a mixture of 3.3×103 spores/ml with 3.3×106 SA+PA/ml. There was no response to a sample containing only 3.3×106 SA+PA/ml. These results illustrate the sensitivity, specificity, reusability, and reliability of array PEMS for in situ, real-time detection of BA spores.

  10. Effect of the Addition of B2O3 on the Density, Microstructure, Dielectric, Piezoelectric and Ferroelectric Properties of K0.5Na0.5NbO3 Ceramics

    NASA Astrophysics Data System (ADS)

    Bharathi, P.; Varma, K. B. R.

    2014-02-01

    Boron oxide (B2O3) addition to pre-reacted K0.5Na0.5NbO3 (KNN) powders facilitated swift densification at relatively low sintering temperatures which was believed to be a key to minimize potassium and sodium loss. The base KNN powder was synthesized via solid-state reaction route. The different amounts (0.1-1 wt%) of B2O3 were-added, and ceramics were sintered at different temperatures and durations to optimize the amount of B2O3 needed to obtain KNN pellets with highest possible density and grain size. The 0.1 wt% B2O3-added KNN ceramics sintered at 1,100 °C for 1 h exhibited higher density (97 %). Scanning electron microscopy studies confirmed an increase in average grain size with increasing B2O3 content at appropriate temperature of sintering and duration. The B2O3-added KNN ceramics exhibited improved dielectric and piezoelectric properties at room temperature. For instance, 0.1 wt% B2O3-added KNN ceramic exhibited d 33 value of 116 pC/N which is much higher than that of pure KNN ceramics. Interestingly, all the B2O3-added (0.1-1 wt%) KNN ceramics exhibited polarization-electric field ( P vs. E) hysteresis loops at room temperature. The remnant polarization ( P r) and coercive field ( E c) values are dependent on the B2O3 content and crystallite size.

  11. Abnormal electronic transition variations of lanthanum-modified lead zironate stannate titanate ceramics near morphotropic phase boundary: A spectroscopic evidence

    SciTech Connect

    Chen, X.; Jiang, K.; Hu, Z. G.; Chu, J. H. [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai 200241 (China); Chen, X. F.; Wang, G. S.; Dong, X. L. [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

    2012-07-02

    The structure-related optical response of (Pb{sub 1-1.5x}La{sub x})(Zr{sub 0.42}Sn{sub 0.40}Ti{sub 0.18})O{sub 3} (100x/42/40/18) ceramics with different compositions has been investigated. Based on x-ray diffraction, the phase transition from rhombohedral to tetragonal structure is revealed between compositions of x = 2.6% and 2.8% near morphotropic phase boundary (MPB). Correspondingly, abnormal spectral response in the photon energy from 1.4 to 6.1 eV is observed near MPB. Furthermore, the blue shift of the two critical points related parameters, which is obtained from fitting the reflectance spectra, indicates that the variation of electronic band structure near MPB is responsible for the anomalous behavior.

  12. 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

    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

    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.

  13. Electrophoretic deposition (EPD) process for lead zirconate titanate (PZT) thick films fabrication and high

    E-print Network

    Boyer, Edmond

    Electrophoretic deposition (EPD) process for lead zirconate titanate (PZT) thick films fabrication lead-zirconate titanate (PZT) thick films were fabricated on non-flat substrate by electrophoretic, the sensitivity and spatial resolution (axial). Lead zirconate titanate (PZT) is commonly used as piezoelectric

  14. Low-cost (0.1BiYbO3-0.9PbTiO3)-PbZrO3-xMn high Curie temperature piezoelectric ceramics with improved high-temperature performance

    NASA Astrophysics Data System (ADS)

    Wang, Yunli; Cai, Kai; Shao, Tianmin; Zhao, Qian; Guo, Dong

    2015-04-01

    Here, we report the structure and performance of a low-cost high Curie temperature (TC) Mn-doped ternary BiYbO3-Pb(Zr,Ti)O3 (BY-PZT-xMn) perovskite piezoelectric ceramic system. The partial substitution of Mn for the A-site Pb, B-site Ti and Zr of the ternary system enhanced both the piezoelectric coefficient and the mechanical quality factor, indicating that the variable valence element induced combinatory soft and hard doped characteristics. The improved electrical performance was found to be related to the improved density and homogeneity, and a correlation between the piezoelectricity and the grain size was also observed. More importantly, a Mn doping level of less than 0.8 mol. % also obviously enhanced the thermal stability of the samples, as reflected by the higher TC and depolarization temperature (Td) measured via both in situ Berlincourt method and annealing experiments, and a correlation between TC and tetragonality of BY-PZT-xMn system was observed. The sample with 0.8 mol. % Mn showed a remarkable overall performance with a d33 of 246 pC/N and a TC around 400 °C, which is expected to be promising for high temperature piezoelectric device applications.

  15. High-Temperature Piezoelectrics with Large Piezoelectric Coefficients

    NASA Astrophysics Data System (ADS)

    Shinekumar, K.; Dutta, Soma

    2015-02-01

    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.

  16. An Experimental Study on the Effect of Temperature on Piezoelectric Sensors for Impedance-Based Structural Health Monitoring

    PubMed Central

    Baptista, Fabricio G.; Budoya, Danilo E.; de Almeida, Vinicius A. D.; Ulson, Jose Alfredo C.

    2014-01-01

    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

  17. Piezoelectric response of charged non-180 domain walls in ferroelectric Zhanfang Li, Hao Wu, and Wenwu Cao

    E-print Network

    Cao, Wenwu

    Piezoelectric response of charged non-180° domain walls in ferroelectric ceramics Zhanfang Li, Hao://jap.aip.org/authors #12;Piezoelectric response of charged non-180 domain walls in ferroelectric ceramics Zhanfang Li,1 Hao walls in ferroelectric ceramic, it can enhance the extrinsic contribution to the piezoelectric

  18. Effect of Al2O3 nanocrystals on the structural and electrical studies of lithium titanate phosphate glass ceramic matrix

    NASA Astrophysics Data System (ADS)

    Krishna Kishore Reddy, Ch.; Rao, R. Balaji; Ramana Reddy, M. V.

    2013-08-01

    A series of lithium phosphate glass ceramics dispersed with Al2O3 nanocrystals were synthesized via high energy ball milling technique. The milling of Al2O3 powder at room temperature for different milling times is 0, 5, 10, 20, 30, 40, 50 and 60 h. The mean particle size distribution was measured using the Scherrer formula for a half width of the diffraction peaks vary from micrometers to ˜24 nm for the milling time at 40 h. The details of compositions chosen for the present study of investigation are given in the general formula: (100-x) [0.4Li2O-0.1TiO2-0.6P2O5]+x 40 h ball milled Al2O3 (where x=0, 2, 4, 6, 8, 10 and 12 mol% ) and labeled as LTPAx (where x is the mole% of 40 h ball milled Al2O3). The average crystallite size of Al2O3 nanoparticles was measured to be 22 nm by transmission electron microscopy (TEM) images, which is in good agreement with the crystallite size calculated from X-ray diffraction (XRD) (24 nm) measurements using Scherrer's formula. The frequency dependent conductivity was explained in the light of conducting nanocrystalline phases such as AlPO4, LiTi2(PO4)3, LiAl2P3O7 precipitated in the LTPA samples.

  19. Dielectric and piezoelectric properties of PbFe1/2Nb1/2O3-PbTiO3 ceramics from the morphotropic phase boundary compositional range.

    PubMed

    Sitalo, Eugene I; Raevski, Igor P; Lutokhin, Alexander G; Blazhevich, Alexei V; Kubrin, Stanislav P; Raevskaya, Svetlana I; Zakharov, Yuriy N; Malitskaya, Maria A; Titov, Victor V; Zakharchenko, Irina N

    2011-09-01

    Dielectric, X-ray, and piezoelectric studies of highly-resistive Li-doped (1-x)PbFe(1/2)Nb(1/2)O(3)-(x)PbTiO(3) (PFN-xPT) ceramics from the 0 ? x ? 0.2 range fabricated by solid-state synthesis and usual sintering have been carried out. Distinct anomalies of dielectric and piezoelectric parameters, corresponding to the transition between rhombohedral (monoclinic) and tetragonal ferroelectric phases, have been observed in pure PFN and PFN-xPT compositions with PbTiO(3) content up to 8 mol.%. The x,T-phase diagram of the PFN-xPT solid solution system has been constructed using these data. PMID:21937325

  20. Giant energy density in [001]-textured Pb(Mg1/3Nb2/3)O3-PbZrO3-PbTiO3 piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Yan, Yongke; Cho, Kyung-Hoon; Maurya, Deepam; Kumar, Amit; Kalinin, Sergei; Khachaturyan, Armen; Priya, Shashank

    2013-01-01

    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.

  1. Variation of Piezoelectric properties and mechanisms across the relaxor-like/Ferroelectric continuum in BiFeO3- (K0.5Bi0.5)TiO3-PbTiO3 ceramics.

    PubMed

    Bennett, James; Shrout, Thomas R; Zhang, Shujun; Owston, Heather E; Stevenson, Tim J; Esat, Faye; Bell, Andrew J; Comyn, T P

    2015-01-01

    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

  2. Piezoelectric Water Drop Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Al Ahmad, Mahmoud

    2014-02-01

    Piezoelectric materials convert mechanical deformation directly into electrical charges, which can be harvested and used to drive micropower electronic devices. The low power consumption of such systems on the scale of microwatts leads to the possibility of using harvested vibrational energy due to its almost universal nature. Vibrational energy harvested using piezoelectric cantilevers provides sufficient output for small-scale power applications. This work reports on vibrational energy harvesting from free-falling droplets at the tip of lead zirconate titanate piezoelectric-based cantilevers. The harvester incorporates a multimorph clamped-free cantilever made of lead zirconate titanate piezoelectric thick films. During the impact, the droplet's kinetic energy is transferred to the form of mechanical stress, forcing the piezoelectric structure to vibrate and thereby producing charges. Experimental results show an instantaneous drop-power of 2.15 mW cm-3 g-1. The scenario of a medium intensity of falling water drops, i.e., 200 drops per second, yielded a power of 0.48 W cm-3 g-1 per second.

  3. A comparison between several approaches of piezoelectric energy harvesting

    Microsoft Academic Search

    E. Lefeuvre; A. Badel; A. Benayad; L. Lebrun; C. Richard; D. Guyomar

    2005-01-01

    This paper compares the performances of vibration-powered electrical generators using a piezoelectric ceramic and a piezoelectric single crystal associated to several power conditioning interfaces. A new approach of the piezoelectric power conversion based on a non linear voltage processing is presented, leading to three novel high-performance techniques. Theoretical predictions and experimental results show that the novel techniques may increase the

  4. Enhanced magnetoelectric effects in composite of piezoelectric ceramics, rare-earth iron alloys, and shape-optimized nanocrystalline alloys.

    PubMed

    Zhang, Jitao; Li, Ping; Wen, Yumei; He, Wei; Yang, Aichao; Lu, Caijiang

    2014-03-01

    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

  5. Flexoelectric sensing using a multilayered barium strontium titanate structure

    NASA Astrophysics Data System (ADS)

    Kwon, S. R.; Huang, W. B.; Zhang, S. J.; Yuan, F. G.; Jiang, X. N.

    2013-11-01

    The flexoelectric effect has been recently explored for its promise in electromechanical sensing. However, the relatively low flexoelectric coefficients of ferroelectrics inhibit the potential to develop flexoelectric sensing devices. In this paper, a multilayered structure using flexoelectric barium strontium titanate (Ba0.65Sr0.35TiO3 or BST) ceramic was fabricated in an attempt to enhance the effective flexoelectric coefficients using its inherent scale effect, and hence to improve the flexoelectric sensitivity. The performances of piezoelectric and flexoelectric cantilevers with the same dimensions and under the same conditions were compared. Owing to the flexoelectric scaling effect, under the same force input, the BST flexoelectric structure generated a higher charge output than its piezoelectric P(VDF-TrFE) and PMN-30PT counterparts when its thickness was less than 73.1 ?m and 1.43 ?m, respectively. Also, amplification of the charge output using the multilayered structure was then experimentally verified. The prototyped structure consisted of three layers of 350 ?m-thick BST plates with a parallel electric connection. The charge output was approximately 287% of that obtained using a single-layer structure with the same total thickness of the multilayered structure under the same end deflection input, which suggests high sensitivity sensing can be achieved using multilayer flexoelectric structures.

  6. Viscoelectroelastic behavior of heterogeneous piezoelectric solids JiangYu Lia)

    E-print Network

    Li, Jiangyu

    -type relaxations in ferroelectric single crys- tals that have been attributed to ferroelectric domain wall motion,8 and relaxation in polycrystalline ceramics due to motion of 90° domain walls.9­12 Complex piezoelectric con been observed in bone,14 and in piezoelectric ceramic/polymer matrix composites.15­17 In bone

  7. Microstructure and piezoelectric properties of 0.95(Na{sub 0.5}K{sub 0.5})NbO{sub 3}-0.05BaTiO{sub 3} ceramics

    SciTech Connect

    Park, Hwi-Yeol; Ahn, Cheol-Woo; Song, Hyun-Cheol; Lee, Jong-Heun; Nahm, Sahn; Uchino, Kenji; Lee, Hyeung-Gyu; Lee, Hwack-Joo [Department of Materials Science and Engineering, Korea University, 1-5 Ka, Anam-Dong, Sungbud-Ku, Seoul 136-701 (Korea, Republic of); International Center for Actuators and Transducers, Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Korea Electronics Technology Institute, 68 Yatap-dong, Bundang-gu, Soeongnam-si, Gyeonggi-do 463-816 (Korea, Republic of); New Materials Evaluation Center, Korea Research Institute of Standards and Science, Daeduk Science Town, Taejon 305-600 (Korea, Republic of)

    2006-08-07

    For 0.95(Na{sub 0.5}K{sub 0.5})NbO{sub 3}-0.05BaTiO{sub 3} (0.95NKN-0.05BT) ceramics sintered at 1040-1075 deg. C, abnormal grain growth occurred but the grain size decreased when the sintering temperature exceeded 1075 deg. C. The dielectric constant ({epsilon}{sub 3}{sup T}/{epsilon}{sub 3}), electromechanical coupling factor (k{sub p}), and piezoelectric constant (d{sub 33}) were considerably increased with increasing relative density and grain size. Evaporation of Na{sub 2}O deteriorated the piezoelectric properties by decreasing the resistivity. To minimize Na{sub 2}O evaporation, specimens were muffled with 0.95NKN-0.05BT powders during the sintering. Improved piezoelectric properties of d{sub 33}=225 pC/N, k{sub p}=36%, and {epsilon}{sub 3}{sup T}/{epsilon}{sub 3}=1058 were obtained for specimen sintered at 1060 deg. C for 2 h with muffling.

  8. Investigation of a new lead-free Bi0.5(Na0.40K0.10)TiO3-(Ba0.7Sr0.3)TiO3 piezoelectric ceramic

    PubMed Central

    2012-01-01

    Lead-free piezoelectric compositions of the (1-x)Bi0.5(Na0.40K0.10)TiO3-x(Ba0.7Sr0.3)TiO3 system (when x = 0, 0.05, 0.10, 0.15, and 0.20) were fabricated using a solid-state mixed oxide method and sintered between 1,050°C and 1,175°C for 2 h. The effect of (Ba0.7Sr0.3)TiO3 [BST] content on phase, microstructure, and electrical properties was investigated. The optimum sintering temperature was 1,125°C at which all compositions had densities of at least 98% of their theoretical values. X-ray diffraction patterns that showed tetragonality were increased with the increasing BST. Scanning electron micrographs showed a slight reduction of grain size when BST was added. The addition of BST was also found to improve the dielectric and piezoelectric properties of the BNKT ceramic. A large room-temperature dielectric constant, ?r (1,609), and piezoelectric coefficient, d33 (214 pC/N), were obtained at an optimal composition of x = 0.10. PMID:22221833

  9. Piezoelectric Polymers

    NASA Technical Reports Server (NTRS)

    Harrison, J. S.; Ounaies, Z.; Bushnell, Dennis M. (Technical Monitor)

    2001-01-01

    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.

  10. Piezoelectric Loss Performance in Pb(Mg1/3Nb2/3)O3-PbTiO3 Single Crystals

    NASA Astrophysics Data System (ADS)

    Rajapurkar, Aditya; Ural, Seyit O.; Zhuang, Yuan; Lee, Ho-Yong; Amin, Ahmed; Uchino, Kenji

    2010-07-01

    Lead magnesium niobate-lead titanate (PMN-PT) single crystals are a suitable replacement over conventional PZT-based ceramics in transducer applications because of their large electromechanical coupling factors (k > 0.90) and piezoelectric constants (d > 1000 pC/N). For single crystals, it is possible to modify the performance by suitable selection of the orientation, and appropriate composition changes or doping can be utilized to improve the mechanical quality factor Qm. In this research, we report the piezoelectric loss performance in PMN-PT single crystals as a function of orientation, doping and vibration mode. The loss characteristics are based on mechanical quality factor Qm as well as the Q values at resonance (QA) and anti-resonance (QB). The Mn-doping resulted in almost twice the enhancement of the mechanical quality factor Qm and the maximum vibration velocity in comparison with the undoped samples.

  11. Piezoelectric valve

    DOEpatents

    Petrenko, Serhiy Fedorovich

    2013-01-15

    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.

  12. Design with Advanced Ceramics Course Outline

    E-print Network

    New South Wales, University of

    11th March Ferroelectric Ceramics and Their Applications 3 17th March 18th March PiezoelectricMATS4002 Design with Advanced Ceramics Course Outline Session 1, 2014 School of Materials Science Ceramics 4 24th March 25th March Electro-optic Ceramics and Fibre-Optic Sensors 5 31st March 1st April

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

    PubMed

    Rubio-Marcos, Fernando; Marchet, Pascal; Romero, Juan José; Fernández, Jose F

    2011-09-01

    This article reviews on the use of Raman spectroscopy for the study of (K,Na,Li)(Nb,Ta,Sb)O(3) lead-free piezoceramics. Currently, this material appears to be one of the most interesting and promising alternatives to the well-known PZT piezoelectric materials. In this work, we prepare piezoceramics with different stoichiometries and study their structural, ferroelectric, and piezoelectric properties. By using both Raman spectroscopy and X-ray diffraction, we establish a direct correlation between the structure and the properties. The results demonstrate that the wavenumber of the A(1g) vibration is proportional to the tetragonality, the remnant polarization, and the piezoelectric coefficients of these materials. Thus, Raman spectroscopy appears as a very useful technique for a fast evaluation of the crystalline structure and the ferroelectric/ piezoelectric properties. PMID:21937314

  14. Enhancing the operational range of piezoelectric actuators by uniaxial compressive preloading

    NASA Astrophysics Data System (ADS)

    Koruza, Jurij; Franzbach, Daniel J.; Schader, Florian; Rojas, Virginia; Webber, Kyle G.

    2015-06-01

    The influence of the uniaxial preload on the off-resonance actuation performance of piezoelectric ceramics was investigated for compressive preload values up to???80?MPa. The study was performed on soft-type lead zirconate titanate (PZT), being the most widely used piezoelectric material. The samples were analysed using the proportional loading method, which enables the simultaneous application of electrical and mechanical loads, thereby mimicking the real operation conditions over the full stress–strain range. An increase of the blocking stress and the longitudinal piezoelectric stress coefficient was observed for all the applied preload values. The optimum properties, a blocking stress of???56?MPa and a free strain of 0.23%, were obtained at a preload value of???40?MPa and electric field of 2?kV?mm?????1. This represents an increase of 16% and 20%, respectively, as compared to the values obtained at the smallest preload. In addition, the maximum work output was increased by about 28%. Finally, the results obtained at the lowest preload of???4?MPa using the proportional loading method were compared to the operational ranges determined by other methods. The comparison revealed large discrepancies between the methods, originating from the different order of the application of electrical and mechanical fields and the inherent nonlinearity of ferroelectric materials. This discrepancy results in decreased actuator performance due to impedance mismatching, demonstrating the need for accurate determination of the actuator’s operational range.

  15. Dielectric and piezoelectric properties of <001> fiber-textured 0.675Pb(Mg1/3Nb2/3)O3-0.325PbTiO3 ceramics

    NASA Astrophysics Data System (ADS)

    Sabolsky, Edward M.; Trolier-McKinstry, Susan; Messing, Gary L.

    2003-04-01

    The 0.675Pb(Mg1/3Nb2/3)O3-0.325PbTiO3 (PMN-32.5PT) ceramic composition (with 1 wt. % excess PbO) was fiber textured in the <001> direction by the templated grain growth process using 5 vol % oriented {001}-BaTiO3 platelet crystals as the templates. The templated ceramics annealed at 1150 °C for 5 h attained texture fractions as high as 0.9. The fiber-textured samples showed an increase in the piezoelectric, electromechanical coupling, and compliance coefficients when poled and measured in the <001>-textured direction. The low drive field (<5 kV/cm) d33 coefficients in the <001>, measured directly from unipolar strain-field measurements, were ˜1150 pC/N. This d33 coefficient is 1.2-1.5 times greater than randomly oriented samples. The poled ?max and ?rt for a 0.9-textured PMN-32.5PT ceramic were 21 500 and 2450, respectively. Factors limiting further property improvements are discussed.

  16. Perovskite ceramic nanoparticles in polymer composites for augmenting bone tissue regeneration.

    PubMed

    Bagchi, Amrit; Meka, Sai Rama Krishna; Rao, Badari Narayana; Chatterjee, Kaushik

    2014-12-01

    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

  17. Perovskite ceramic nanoparticles in polymer composites for augmenting bone tissue regeneration

    NASA Astrophysics Data System (ADS)

    Bagchi, Amrit; Rama Krishna Meka, Sai; Narayana Rao, Badari; Chatterjee, Kaushik

    2014-12-01

    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.

  18. Amplifying transmission and compact suspension for a low-profile, large-displacement piezoelectric actuator

    PubMed Central

    Domke, J F; Rhee, C-H; Liu, Z; Wang, T D; Oldham, K R

    2012-01-01

    A low-profile, piezoelectrically-driven microactuator is presented that achieves very large stroke lengths within size constraints suitable for certain endoscopic microscopy applications. The actuator utilizes a transmission consisting of lever arm and chevron-beam structures to amplify high-force, low-displacement motion of a ceramic lead-zirconate-titanate (PZT) brick into large displacement of a translational platform. For ±120 V input, a full range of 486 ?m of motion is achieved, with natural frequency greater than 500 Hz. This corresponds to an anticipated In addition, the lateral translational platform is supported by a redesign of common folded silicon flexures to provide large transverse and vertical stiffness when the width of the actuator is limited. PMID:23180908

  19. Numerical simulation of piezoelectric effect of bone under ultrasound irradiation

    NASA Astrophysics Data System (ADS)

    Hosokawa, Atsushi

    2015-07-01

    The piezoelectric effect of bone under ultrasound irradiation was numerically simulated using an elastic finite-difference time-domain method with piezoelectric constitutive equations (PE-FDTD method). First, to demonstrate the validity of the PE-FDTD method, the ultrasound propagation in piezoelectric ceramics was simulated and then compared with the experimental results. The simulated and experimental waveforms propagating through the ceramics were in good agreement. Next, the piezoelectric effect of human cortical bone on the ultrasound propagation was investigated by PE-FDTD simulation. The simulated result showed that the difference between the waveforms propagating through the bone without and with piezoelectricity was negligible. Finally, the spatial distributions of the electric fields in a human femur induced by ultrasound irradiation were simulated. The electric fields were changed by a bone fracture, which depended on piezoelectric anisotropy. In conclusion, the PE-FDTD method is considered to be useful for investigating the piezoelectric effect of bone.

  20. Voltage generation of piezoelectric cantilevers by laser heating

    PubMed Central

    Hsieh, Chun-Yi; Liu, Wei-Hung; Chen, Yang-Fang; Shih, Wan Y.; Gao, Xiaotong; Shih, Wei-Heng

    2012-01-01

    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

  1. Design and fabrication of piezoelectric nanocomposite structures for microdevice applications

    NASA Astrophysics Data System (ADS)

    Palevicius, Arvydas; Ponelyte, Sigita; Guobiene, Asta; Prosycevas, Igoris; Puiso, Judita; Sakalys, Rokas

    2013-10-01

    We present a new group of piezoelectric nanocomposite thin films based on integrating piezoelectric material poly(vinylidene fluoride) and nanoparticles of barium titanate in a matrix of an organic polymer poly(methyl methacrylate). Implementation of piezoelectric properties in designed new nanocomposites allows us not only to increase the sensitivity and functionality of the overall system, where this material is used, but also to expand the application fields in sensing and actuating systems. Results implied that new nanostructures fabricated by nanoimprint lithography exhibit good piezoelectric, surface, and mechanical properties and allow independent control of tribological properties. Formed nanocomposite systems were integrated in designing optical components employed in medicine for sensing applications.

  2. Voltage generation of piezoelectric cantilevers by laser heating.

    PubMed

    Hsieh, Chun-Yi; Liu, Wei-Hung; Chen, Yang-Fang; Shih, Wan Y; Gao, Xiaotong; Shih, Wei-Heng

    2012-11-15

    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

  3. New lead-free piezoelectric ceramics based on (K0.48Na0.52)(Nb0.95Ta0.05)O3-Bi0.5(Na0.7K0.2Li0.1)0.5ZrO3.

    PubMed

    Cheng, Xiaojing; Wu, Jiagang; Wang, Xiaopeng; Zhang, Binyu; Zhu, Jianguo; Xiao, Dingquan; Wang, Xiangjian; Lou, Xiaojie

    2014-03-01

    (1 - x)(K0.48Na0.52)(Nb0.95Ta0.05)O3-xBi0.5(Na0.7K0.2Li0.1)0.5ZrO3 lead-free piezoelectric ceramics with a new type of phase boundary have been designed and fabricated. This phase boundary lies in the compositional range of 0.04 ? x ? 0.05, and is formed by the coexistence of the rhombohedral, orthorhombic, and tetragonal phases. Interestingly, we found that the ferroelectric, dielectric, and piezoelectric properties of the ceramics with compositions near the phase boundary are significantly enhanced. In particular, the ceramic with x = 0.045 shows the best piezoelectric behavior of d33 ? 290 pC/N and kp ? 0.42 among all the compositions studied in this work, and it also exhibits a good thermal stability at annealing temperatures of ?270 °C. All these results indicate that such a material system is a good candidate for lead-free piezoelectric applications in the future. PMID:24452129

  4. Self-powered wireless sensor system using MEMS piezoelectric micro power generator (PMPG)

    E-print Network

    Xia, YuXin, M.B.A. Sloan School of Management.

    2006-01-01

    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 ...

  5. Diffuse phase transition and electrical properties of lead-free piezoelectric (LixNa1-x)NbO3 (0.04 ? x ? 0.20) ceramics near morphotropic phase boundary

    NASA Astrophysics Data System (ADS)

    Mitra, S.; Kulkarni, A. R.; Prakash, Om

    2013-08-01

    Temperature-dependent dielectric permittivity of lead-free (LixNa1-x)NbO3 for nominal x = 0.04-0.20, prepared by solid state reaction followed by sintering, was studied to resolve often debated issue pertaining to exactness of morphotropic phase boundary (MPB) location besides structural aspects and phase stability in the system near MPB. Interestingly, a diffuse phase transition has been observed in the dielectric permittivity peak arising from the disorder induced in A-site and structural frustration in the perovskite cell due to Li substitution. A partial phase diagram has been proposed based on temperature-dependent dielectric permittivity studies. The room temperature piezoelectric and ferroelectric properties were investigated and the ceramics with x = 0.12 showed relatively good electrical properties (d33 = 28 pC/N, kp = 13.8%, Qm = 440, Pr = 12.5 ?C/cm2, Ec = 43.2 kV/cm, and Tm = 340 °C). These parameter values make this material suitable for piezoelectric resonator and filter applications. Moreover, a high dielectric permittivity (?'r = 2703) with broad diffuse peak near transition temperature, and low dielectric loss (<4%) over a wide temperature range (50-250 °C) found in this material may also have a potential application in high-temperature multilayer capacitors in automotive and aerospace related industries.

  6. 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

    BP McGrail; HT Schaef; JP Icenhower; PF Martin; VL Legore

    1999-01-01

    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

  7. 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)

    Mahmud, Iqbal; Ur, Soon-Chul; Yoon, Man-Soon

    2014-07-01

    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.

  8. 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.

  9. Effects of K content on the dielectric, piezoelectric, and ferroelectric properties of 0.95(K{sub x}Na{sub 1-x})NbO{sub 3}-0.05LiSbO{sub 3} lead-free ceramics

    SciTech Connect

    Wu Jiagang; Xiao Dingquan; Zhu Jianguo; Yu Ping [Department of Materials Science, Sichuan University, Chengdu 610064 (China); Wang Yuanyu [Department of Materials Science, Sichuan University, Chengdu 610064 (China) and College of Materials Science and Metallurgy Engineering, Guizhou University, Guizhou 550003 (China)

    2008-01-15

    The effects of K content on the dielectric, piezoelectric, and ferroelectric properties of 0.95(K{sub x}Na{sub 1-x})NbO{sub 3}-0.05LiSbO{sub 3} (0.95K{sub x}NN-0.05LS) (x=0.25-0.75) lead-free piezoelectric ceramics prepared by conventional solid-state sintering were studied. The experimental results show that the dielectric, piezoelectric, and ferroelectric properties strongly depend on K content in the 0.95K{sub x}NN-0.05LS ceramics. The 0.95K{sub x}NN-0.05LS (x=0.40) ceramics exhibit enhanced electrical properties (d{sub 33}{approx_equal}280 pC/N; k{sub p}{approx_equal}49.4%; T{sub c}{approx}364 deg. C; T{sub o-t}=25 deg. C; {epsilon}{sub r}{approx_equal}1463; tan {delta}{approx_equal}2.3%; P{sub r}{approx}30.8 {mu}C/cm{sup 2}; E{sub c}{approx}14.0 kV/cm). The enhanced electrical properties of 0.95K{sub x}NN-0.05LS (x=0.40) ceramics are attributed to the polymorphic phase transition near room temperature. These results show that 0.95K{sub x}NN-0.05LS (x=0.40) ceramic is a promising lead-free piezoelectric material.

  10. Characterizing Titan's Upper Atmosphere Using the Titan

    E-print Network

    Johnson, Robert E.

    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

  11. Piezoelectric properties of 0.5(Ba0.7Ca0.3TiO3) - 0.5[Ba(Zr0.2Ti0.8)O3] ferroelectric lead-free laser deposited thin films

    NASA Astrophysics Data System (ADS)

    Piorra, A.; Petraru, A.; Kohlstedt, H.; Wuttig, M.; Quandt, E.

    2011-05-01

    Ferroelectric lead-free thin films of 0.5(Ba0.7Ca0.3TiO3) - 0.5[Ba(Zr0.2Ti0.8)O3] (BCZT) were successfully deposited by pulsed laser deposition on Pt/TiO2/SiO2/Si substrates using a ceramic BCZT target prepared by conventional solid state reaction. The in (111) direction orientated 600 nm thick films shows a clamped piezoelectric response of approximately d33,f = 80 pm/V and a dielectric coefficient of about ?r = 1010; these are close to values obtained for lead zirconate titanate (PZT) films.

  12. Study of BNKLBT-1.5 lead-free ceramic/epoxy 1-3 composites

    NASA Astrophysics Data System (ADS)

    Choy, S. H.; Li, W. K.; Li, H. K.; Lam, K. H.; Chan, H. L. W.

    2007-12-01

    Bismuth sodium titanate based lead-free ceramic fiber with the chemical formula of 0.885(Bi0.5Na0.5)TiO3-0.05(Bi0.5K0.5)TiO3-0.015(Bi0.5Li0.5)TiO3-0.05BaTiO3, BNKLBT-1.5, has been fabricated by a powder-based extrusion method. The ceramic fibers with 400?m diameter were well crystallized after being calcined at 800°C and sintered at 1170°C. The piezoelectric and ferroelectric properties of the single fiber were found to be 155pC/N and ˜34.5?C/cm2, 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.

  13. RMS TITANIC

    NSDL National Science Digital Library

    Miss Law

    2010-04-20

    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 ...

  14. Polar glass ceramics

    Microsoft Academic Search

    A. Halliyal; A. S. Bhalla; R. E. Newnham; L. E. Cross

    1981-01-01

    Pyroelectric-piezoelecric glass ceramics of polar materials like Li2Si2O5, Ba2TiGe2O8, Ba2TiSi2O8, and Various compositions in the systems Li2O-B2O3, Li2O-SiO2-ZnO, Li2O-SiO2-B2O3 have been prepared by oriented recrystallization of the glasses under a strong temperature gradient, providing a simple inexpensive process for preparing piezoelectric and pyroelectric materials. High pyroelectric responses were observed in these glass-ceramics. Values of piezoelectric d33 coefficients, frequency constants, electromechanical

  15. Piezoelectric Energy Harvester for Batteryless Switch Devices

    NASA Astrophysics Data System (ADS)

    Kim, Min-Soo; Lee, Sung-Chan; Kim, Sin-Woong; Jeong, Soon-Jong; Kim, In-Sung; Song, Jaesung

    2013-10-01

    This study investigated a piezoelectric energy-harvesting system for a mechanical switch device. Piezoelectric ceramics of 0.4Pb(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3 were prepared by using a conventional solid-state reaction method. Li2O, Bi2O3, and CuO additions were used as sintering aids to develop piezoelectric ceramics for low-temperature sintering. Multilayer piezoelectric ceramics with 10×10×3 mm3 sizes and with Ag-Pd inner electrodes were manufactured by using the conventional tape-casting method with the prepared powder. A prototype of a piezoelectric batteryless switch device using the multilayer ceramics was produced. It showed an output peak-to-peak voltage of 3.8 V and an output power per strike of 18 µW. The performance of the device was good enough for practical use.

  16. Nanoindentation response of piezoelectric nano-islands

    NASA Astrophysics Data System (ADS)

    Cheng, Guang; Sriram, Sharath; Bhaskaran, Madhu; Venkatesh, T. A.

    2014-09-01

    Through three-dimensional finite element modeling, it is demonstrated that the nanoindentation response of piezoelectric nano-islands is strongly dependent on the shape of the nano-island and the depth of indentation. For indentations that are relatively deep (i.e., greater than 5% of the height of the islands), the substrate's elastic and plastic properties have a strong influence on the indentation response of piezoelectric nano-islands with substrate plasticity resulting in a significant reduction in the mechanical and electrical indentation stiffness. The predictions of the finite element models compare well with experiments on nano-islands of strontium-doped lead zirconate titanate.

  17. Stresa, Italy, 26-28 April 2006 OPTIMIZATION OF PIEZOELECTRIC ELECTRICAL GENERATORS

    E-print Network

    Boyer, Edmond

    harvesting using piezoelectric materials have been developed over the past few years. OptimizationStresa, Italy, 26-28 April 2006 OPTIMIZATION OF PIEZOELECTRIC ELECTRICAL GENERATORS POWERED generators using PZT piezoelectric ceramic associated to two different power conditioning circuits. A new

  18. Piezoelectric piggy-back microactuator for hard disk drive

    Microsoft Academic Search

    Yoshikazu Soeno; Sliinji Ichikawa; Takamitsu Tsuna; Yoshikazu Sato; Isamu Sato

    1999-01-01

    A new piezoelectric piggy-back microactuator for high density hard disk drives was designed and fabricated to achieve more accurate positioning of the magnetic head and increasing servo bandwidth. The microactuator is made of stiff piezoelectric ceramic material to actuate the slider on which the head-element is formed. It is designed to amplify the actuating displacement. The basic mechanical performance of

  19. Raman and Dielectric Studies on Lead free (K0.5Na0.5) NbO3 Piezoelectric Ceramics

    NASA Astrophysics Data System (ADS)

    Mahesh, P.; Pamu, D.

    2015-02-01

    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.

  20. Strain engineered barium strontium titanate for tunable thin film resonators

    SciTech Connect

    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

    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.

  1. Strain engineered barium strontium titanate for tunable thin film resonators

    NASA Astrophysics Data System (ADS)

    Khassaf, H.; Khakpash, N.; Sun, F.; Sbrockey, N. M.; Tompa, G. S.; Kalkur, T. S.; Alpay, S. P.

    2014-05-01

    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.

  2. 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

    BP McGrail; HT Schaef; JP Icenhower; PF Martin; RD Orr; VL Legore

    1999-09-13

    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.

  3. Piezoelectric and electrostrictive materials for transducer applications

    Microsoft Academic Search

    L. E. Cross; R. E. Newnham; G. R. Barsch; J. V. Biggers

    1986-01-01

    On the topic of piezoelectric composites, work over the year has focused primarily upon materials with 0:3 phase connectivity. Using chemically co-precipitated powders with high purity and surface perfection, it has been possible to raise the poling field substantially and realize markedly improved properties in lead titanate based materials. X-ray measurements confirm excellent poling and the dhgh figure of merit

  4. Structural investigations on lead titanate xerogels and aerogels

    Microsoft Academic Search

    P. Lobmann; J. Gross; W. Glaubitt; J. Fricke

    1996-01-01

    The preparation of highly porous piezoelectric materials offers a promising route to ultrasonic transducers with low acoustic impedances suitable for ranging applications or gas flow measurements. Sol—gel derived lead titanate gels were dried at ambient pressure and under supercritical conditions. Electron microscopy, thermogravimetry and dilatometer measurements were made on samples of the prepared materials. Nitrogen adsorption experiments were performed to

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

    E-print Network

    Doshi, Sukanya 1988-

    2012-12-10

    Piezoelectric actuators have been developed in various forms ranging from discrete layered composites to functionally graded composites. These composite actuators are usually made up of differentially poled piezoelectric ceramics. This study...

  6. High temperature, high power piezoelectric composite transducers.

    PubMed

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, Stewart

    2014-01-01

    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

  7. Local piezoelectric behavior in PZT-based thin films for ultrasound transducers

    NASA Astrophysics Data System (ADS)

    Griggio, Flavio

    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.

  8. Crack tip 90 domain switching in tetragonal lanthanum-modified lead zirconate titanate under an

    E-print Network

    Zhu, Ting

    ) Lanthanum-modified lead zirconate titanate ferroelectric ceramics (Pb0.96La0.04)(Zr0.40Ti0.60)0.99O3 were. I. INTRODUCTION Perovskite-type ferroelectric ceramics have been used as sensors, actuators conditions. However, ferroelectric ceramics are brittle and they may degrade under com- bined electrical

  9. Overview of multilayer ceramic actuator program at C-MET

    NASA Astrophysics Data System (ADS)

    Raghu, N.; Kumar, V.; Dayas, K. R.; Rao, I. C.

    2003-10-01

    One of the major programs being undertaken in our unit is, development of actuator materials and conversion of these materials into multilayer actuator devices. In order to achieve this objective, development of piezoelectric and electrostrictive materials are also being attempted. A simple and novel chemical precipitation route has been adopted for the synthesis of nano-actuator materials. Lead Zirconate Titanate (PZT) powder, free of agglomerates, phase pure, good chemical homogeneity and of 50 - 75 nm size has been synthesized. Synthesis of nano Ba(Sn,Ti)O3 which shows linear, nearly hysteresis free strain curve is also discussed. Phase pure electrostrictive Lead Magnesium Niobate-Lead Titanate (PMN-PT) powder with a dielectric constant of 25,000 and a Tc of 38°C was prepared through double-step process. C-MET has state of the art facility for multilayer (ML) ceramic processing. These Nano-PZT powders have been converted into 50 micron green tapes through tape casting technique. Characteristics of these synthesized materials and the fabrication of ML actuators there from are presented.

  10. Titanic Research Link

    NSDL National Science Digital Library

    Miss Law

    2012-01-17

    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 ...

  11. ORNL debuts Titan supercomputer

    E-print Network

    Pennycook, Steve

    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

  12. Miniature piezoelectric triaxial accelerometer measures cranial accelerations

    NASA Technical Reports Server (NTRS)

    Deboo, G. J.; Rogallo, V. L.

    1966-01-01

    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.

  13. Piezoelectric transducer

    NASA Technical Reports Server (NTRS)

    Conragan, J.; Muller, R. S.

    1970-01-01

    Transducer consists of a hybrid thin film and a piezoelectric transistor that acts as a stress-sensitive device with built-in gain. It provides a stress/strain transducer that incorporates a signal amplification stage and sensor in a single package.

  14. Titan Recreation-Titan Bowl and Billiards Student Engagement Report

    E-print Network

    de Lijser, Peter

    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

  15. Titan Recreation-Titan Bowl and Billiards Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Recreation-Titan Bowl and Billiards Student Engagement Report FY 2010-2011 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

  16. Bulk Crystal Growth of Piezoelectric PMN-PT Crystals Using Gradient Freeze Technique for Improved SHM Sensors

    NASA Technical Reports Server (NTRS)

    Aggarwal, Mohan D.; Kochary, F.; Penn, Benjamin G.; Miller, Jim

    2007-01-01

    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.

  17. Effect on the grain size of single-mode microwave sintered NiCuZn ferrite and zinc titanate dielectric resonator ceramics.

    PubMed

    Sirugudu, Roopas Kiran; Vemuri, Rama Krishna Murthy; Venkatachalam, Subramanian; Gopalakrishnan, Anisha; Budaraju, Srinivasa Murty

    2011-01-01

    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

  18. Microstructure and phase transformation of zinc titanate thin films

    Microsoft Academic Search

    Ying-Chieh Lee; Yen-Lin Huang; Wen-His Lee; Bao-Hsing Chen; Fuh-Sheng Shieu

    2010-01-01

    ZnTiO3 have excellent microwave dielectric properties, can be as high-frequency (>10 GHz) capacitors among the passive components industry. In this study, the microstructures and phase transformations of zinc titanate thin films were investigated. Zinc titanate thin films were synthesized on SiO2\\/Si(100) substrates by RF magnetron sputtering using a sintered ceramics target of ZnTiO3 at various Ar\\/O2 mixing ratios (100\\/0, 90\\/10,

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

    Microsoft Academic Search

    Tsuguto Takeuchi; Toshihiko Tani; Yasuyoshi Saito

    1999-01-01

    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

  20. Properties of Bi4Ti3O12-(Na1\\/2Bi1\\/2)TiO3 Piezoelectric Ceramics

    Microsoft Academic Search

    Alessandra Sanson; Roger W. Whatmore

    2002-01-01

    Ceramics of the series (1-x)Bi4Ti3O12-x(Na1\\/2Bi1\\/2)TiO3 (BTO-NBT) were made using a conventional mixed oxide and carbonate process. The structural properties revealed that the system passes through the formation of Aurivillius compounds with increasing number of perovskite blocks for an increasing amount of NBT up to a maximum of four. Regions of coexistence of two layered compounds are also present. A perovskite

  1. Piezoelectric Energy Harvesting (DMR-0819860) Y. Qi, M. P. Haataja & M. C. McAlpine, Princeton University

    E-print Network

    Petta, Jason

    Piezoelectric Energy Harvesting (DMR-0819860) Y. Qi, M. P. Haataja & M. C. McAlpine, Princeton stretchable, biocompatible rubbers could yield breakthroughs in implantable or wearable energy harvesting and parallel process for transferring crystalline piezoelectric nanoribbons of lead zirconate titanate (PZT

  2. Dielectric spectroscopy of Dy2O3 doped (K0.5Na0.5)NbO3 piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Mahesh, P.; Subhash, T.; Pamu, D.

    2014-06-01

    We report the dielectric properties of ( K 0.5 Na 0.5 ) NbO 3 ceramics doped with x wt% of Dy 2 O 3 (x= 0.0-1.5 wt%) using the broadband dielectric spectroscopy. The X-ray diffraction studies showed the formation of perovskite structure signifying that Dy 2 O 3 diffuse into the KNN lattice. Samples doped with x > 0.5 wt% exhibit smaller grain size and lower relative densities. The dielectric properties of KNN ceramics doped with Dy 2 O 3 are enhanced by increasing the Dy 3+ content; among the compositions studied, x = 0.5 wt% exhibited the highest dielectric constant and lowest loss at 1MHz over the temperature range of 30°C to 400°C. All the samples exhibit maximum dielectric constant at the Curie temperature (˜ 326°C) and a small peak in the dielectric constant at around 165°C is due to a structural phase transition. At the request of all authors, and by agreement with the Proceedings Editors, a corrected version of this article was published on 19 June 2014. The full text of the Corrigendum is attached to the corrected article PDF file.

  3. Crack Growth in Ferroelectric Ceramics Driven by Cyclic Polarization Switching

    Microsoft Academic Search

    C. S. Lynch; L. Chen; Z. Suo; R. M. Mcmeeking; W. Yang

    1995-01-01

    Ferroelectric ceramics are susceptible to stable crack growth under cyclic electric field of high magnitude. The stresses originate from mismatch strains induced by the electric field around inhomogeneities, such as processing flaws, terminated electrodes and the cracks themselves. The phenomenon is studied using a lead lanthanum zirconate-titanate ceramic. A flaw is indented on the surface of a ceramic sample. Subject

  4. Electrical properties of lead-free 0.98(Na0.5K0.5)NbO3-0.02Ba(Zr0.52Ti0.48)O3 piezoelectric ceramics by optimizing sintering temperature.

    PubMed

    Lee, Seung-Hwan; Lee, Sung-Gap; Lee, Young-Hie

    2012-01-01

    Lead-free 0.98(Na0.5K0.5)NbO3-0.02Ba(Zr0.52Ti0.48)O3 [0.98NKN-0.02BZT] ceramics were fabricated by the conventional mixed oxide method with sintering temperature at 1,080°C to 1,120°C. The results indicate that the sintering temperature obviously influences the structural and electrical properties of the sample. For the 0.98NKN-0.02BZT ceramics sintered at 1,080°C to 1,120°C, the bulk density increased with increasing sintering temperature and showed a maximum value at a sintering temperature of 1,090°C. The dielectric constant, piezoelectric constant [d33], electromechanical coupling coefficient [kp], and remnant polarization [Pr] increased with increasing sintering temperature, which might be related to the increase in the relative density. However, the samples would be deteriorated when they are sintered above the optimum temperature. High piezoelectric properties of d33 = 217 pC/N, kp = 41%, dielectric constant = 1,951, and ferroelectric properties of Pr = 10.3 ?C/cm2 were obtained for the 0.98NKN-0.02BZT ceramics sintered at 1,090°C for 4 h. PMID:22221445

  5. Nanoscale electrical probing of heterogeneous ceramics: the case of giant permittivity calcium copper titanate (CaCu3Ti4O12)

    NASA Astrophysics Data System (ADS)

    Fiorenza, Patrick; Raineri, Vito; Ferrarelli, Matthew C.; Sinclair, Derek C.; Lo Nigro, Raffaella

    2011-03-01

    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.

  6. Nanoscale electrical probing of heterogeneous ceramics: the case of giant permittivity calcium copper titanate (CaCu3Ti4O12).

    PubMed

    Fiorenza, Patrick; Raineri, Vito; Ferrarelli, Matthew C; Sinclair, Derek C; Lo Nigro, Raffaella

    2011-03-01

    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

  7. Development of Bismuth-based Lead-free Piezoelectric Materials: Thin Film Piezoelectric Materials via PVD and CSD Routes

    NASA Astrophysics Data System (ADS)

    Jeon, Yu Hong

    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).

  8. Titan 2D: Understanding Titan’s Seasonal Atmospheric Cycles

    NASA Astrophysics Data System (ADS)

    Wong, Michael; Zhang, X.; Li, C.; Hu, R.; Shia, R.; Newman, C.; Müller-Wodarg, I.; Yung, Y.

    2013-10-01

    In this study, we present results from a novel two-dimensional (2D) model that simulates the physics and chemistry of Titan’s atmosphere. Despite being an icy moon of Saturn, Titan is the only Solar System object aside from Earth that is sheathed by a thick nitrogen-dominated atmosphere. This vulnerable gaseous envelope—an embodiment of a delicate coupling between photochemistry, radiation, and dynamics—is Nature’s laboratory for the synthesis of complex organic molecules. Titan’s large obliquity generates pronounced seasonal cycles in its atmosphere, and the Cassini spacecraft has been observing these variations since 2004. In particular, Cassini measurements show that the latitudinal distribution of Titan’s rich mélange of hydrocarbon species follows seasonal patterns. The mixing ratios of hydrocarbons increase with latitude towards the winter pole, suggesting a pole-to-pole circulation that reverses after equinox. Using a one-dimensional photochemical model of Titan’s atmosphere, we show that photochemistry alone cannot produce the observed meridional hydrocarbon distribution. This necessitates the employment of a 2D chemistry-transport model that includes meridional circulation as well as diffusive processes and photochemistry. Of additional concern, no previous 2D model of Titan extends beyond 500 km altitude—a critical limitation since the peak of methane photolysis is at 800 km. Our 2D model is the first to include Titan’s stratosphere, mesosphere, and thermosphere. The meridional circulation in our 2D model is derived from the outputs of two general circulation models (GCMs): the TitanWRF GCM (Newman et al. 2011) covering the troposphere, stratosphere, and lower mesosphere, and a thermosphere general circulation model (TGCM) covering the remainder of the atmosphere through the thermosphere (Müller-Wodarg et al. 2003; 2008). This presentation will focus on the utilization of these advances applied to the 2D Caltech/JPL KINETICS model to understand the seasonal and meridional distribution of hydrocarbons as well as other atmospheric cycles on Titan.

  9. Titanic: A Statistical Exploration.

    ERIC Educational Resources Information Center

    Takis, Sandra L.

    1999-01-01

    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)

  10. Ferroelectric ceramic electrooptic materials and devices

    Microsoft Academic Search

    C. E. Land; P. D. Thacher

    1969-01-01

    Thin polished plates of hot-pressed rhombohedral lead zirconate-lead titanate ceramics possess one of two types of electro-optic properties depending on the nominal grain diameter. In poled coarse-grained ceramics the electrooptic effect of importance for devices is the dependence of the light scattering properties on the orientation of the ceramic polar axis (electrical poling direction). The light scattering properties are essentially

  11. Electron microscopy of X7R and Y5V type barium titanate multilayer ceramic capacitors with noble and base metal electrodes

    NASA Astrophysics Data System (ADS)

    Feng, Qiquan

    Two types of multilayer ceramic capacitors (MLCCs), Y5V with Ni electrodes and X7R with Ag/Pd electrodes, were characterized by transmission electron microscopy (TEM) and showed quite different microstructures which determined their dielectric behaviors. In X7R-type MLCCs, core-shell structures were observed. The flat dielectric constant-temperature curves obtained from these materials can be interpreted in terms of the internal stress states in individual grains. The stress states were observed using weak beam dark field (WBDF) microscopy. The strain contours observed were formed by distorted crystal planes and were dependent on the stress state of the crystal instead of crystal symmetry. The stress distribution in individual grains was determined by both the thickness ratio of shell and core and the geometrical relationship of the core and the shell. (111) lamella twins and dislocation loops in the paraelectric phases of BaTiO3 doped with Bi2O3 were analyzed by TEM under two-beam conditions. Y5V-type MLCCs based on re-oxidized Ba(Ti 0.88,Zr0.12)O3 (BTZ) materials exhibited frequency relaxation effects. Multi-domain structures coexisting in one grain were observed at dynamical diffraction conditions. Uneven distribution of internal stress and coexistence of multi-phases and multi-domains in individual grains were considered to be responsible for the frequency relaxor behavior observed in these materials. The compatibility of electrodes and dielectrics in cofired MLCCs with both Ni and Ag/Pd electrodes was characterized by TEM using tripod polished samples. NiO lamellae and P-rich intermediate layers were found in highly accelerated life tested (HALT) MLCCs with Ni electrodes. It is believed that Mn ions were reduced by the Ni electrodes, as P-rich and Mn-rich segregated layers were observed in the virginal non-life tested MLCCs. No silver diffusion was found in either the BaTiO3 based perovskite lattices or the flux phases in air-fired X7R type MLCCs.

  12. Does Titan have oceans?

    NASA Astrophysics Data System (ADS)

    Lunine, J. I.

    1994-04-01

    Titan is one of the few worlds in the solar system whose essential nature remains hidden. Satellite data from Voyager are examined. Remote sensing investigations from Earth are explored. Possible models of Titan's surface are reviewed. A closer look at Titan would provide useful information. The data to be gathered by the planetary mission Cassini is discussed.

  13. Your Impact. Titan Pride?

    E-print Network

    de Lijser, Peter

    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

  14. Titan Haze

    NASA Technical Reports Server (NTRS)

    Anderson, Carrie M.; West, Robert; Lavvas, Panayotis

    2011-01-01

    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.

  15. The effect of polymer fill ratio in pillar structure for piezoelectric energy harvester

    NASA Astrophysics Data System (ADS)

    Lee, Kyoung-Soo; Shin, Dong-Jin; Chae, Moon-Soon; Koo, Sang-Mo; Ha, Jae-Geun; Koh, Jung-Hyuk; Cho, Kyung-Ho; Seo, Chang-Eui; Jeong, Soon-Jong

    2013-07-01

    One method of energy harvesting is to use piezoelectric devices, which are able to interchange electrical energy and mechanical strain or vibration. This study is to experimentally investigate the behavior of a piezoelectric energy harvester that was constructed with an array of pillar structures made of 0.2(PbMg1/3Nb2/3O3)-0.8(PbZr0.475Ti0.525O3) with polymer fill. Additionally, the aim of this study is to optimize the fill ratio of the composite piezoelectric ceramics and polymer structure. 0.2(PbMg1/3Nb2/3O3)-0.8(PbZr0.475Ti0.525O3) ceramics were employed as piezoelectric ceramic pillars, prepared in a rectangular shape. These piezoelectric ceramic pillars were sintered separately and attached to a bottom metallic electrode with poled states. The optimum ratio of ceramic pillar and elastic polymer ratio will be discussed. Piezoelectric properties will be discussed including the piezoelectric constant, piezoelectric voltage constants, and electromechanical coupling coefficient. We will present how the harvested energy depends on the lead resistor.

  16. A ceramic composite thermal insulation

    NASA Technical Reports Server (NTRS)

    1967-01-01

    Ceramic composite thermal insulation comprised of alumina-silica fibers, pigmentary potassium titanate, and asbestos fibers, bonded with a colloidal silica sol has improved insulating capabilities to both radiant and convective heat. Gelation of the colloidal silica sol prevents binder migration.

  17. Lead-based titanate ferroelectric thin films fabricated by a sol–gel technique

    Microsoft Academic Search

    D. G. Wang; C. Z. Chen; J. Ma; T. H. Liu

    2008-01-01

    Because of its excellent ferroelectric properties including piezoelectricity, thermoelectricity and photoelectricity, the lead-based titanate ferroelectric thin films have been widely used in the high-tech fields such as microelectronics, optoelectronics, integrated optics and microelectro-mechanical system. As a significant technique in preparing thin films, the sol–gel method has achieved great success in preparing the lead-based titanate ferroelectric thin films. In this paper,

  18. Piezoelectric Effect

    NSDL National Science Digital Library

    In this activity, by the Concord Consortium's Molecular Literacy project, students explore the piezoelectric effect, which is the conversion between electricity and mechanical motion. The model used in this activity shows this conversion and users can manipulate the model to change the voltage and observe changes to a crystal. The activity itself is a java-based interactive resource built upon the free, open source Molecular Workbench software. In these activities, students are allowed to explore at their own pace in a digital environment full of demonstrations, illustrations, and models they can manipulate. In addition to the activity, visitors will find an overview of the activity and central and key concepts.

  19. Interior of Titan

    NASA Technical Reports Server (NTRS)

    Stevenson, David J.

    1992-01-01

    General principles of Titan formation and evolution are addressed. Attention is focused on the volatile reservoir (defined as all constituents more volatile than water) of Titan's interior. Volatile poor models, in which Titan is like Granymede or Callisto with a thin (observed) volatile veneer are discussed and discarded. Volatile rich models in which the present Titan consists of a methane clathrate shell overlying a deep water ammonia ocean and solid ammonia hydrate are discussed. Titan has a central core of rock which is about one half of the total mass, and a superficial hydrocarbon 'ocean' stored in subsurface caverns and pore space.

  20. Mechanically activating formation of layered structured bismuth titanate

    Microsoft Academic Search

    Biljana D. Stojanovic; C. O. Paiva-Santos; C. Jovalekic; A. Z. Simoes; F. M. Filho; Z. Lazarevic; J. A. Varela

    2006-01-01

    Bismuth titanate—Bi4Ti3O12 (BIT) with wide application in the electronic industry as capacitors, memory devices and sensors is the simplest compound in the Aurivillius family, which consists of (Bi2O2)2+ sheets alternating with (Bi2Ti3O10)2? perovskite-like layers. The synthesis of more resistive BIT ceramics would be preferable advance in obtaining of well-densified ceramic with small grains randomly oriented to limit the conductivity along

  1. Revisiting the blocking force test on ferroelectric ceramics using high energy x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Daniel, L.; Hall, D. A.; Koruza, J.; Webber, K. G.; King, A.; Withers, P. J.

    2015-05-01

    The blocking force test is a standard test to characterise the properties of piezoelectric actuators. The aim of this study is to understand the various contributions to the macroscopic behaviour observed during this experiment that involves the intrinsic piezoelectric effect, ferroelectric domain switching, and internal stress development. For this purpose, a high energy diffraction experiment is performed in-situ during a blocking force test on a tetragonal lead zirconate titanate (PZT) ceramic (Pb0.98Ba0.01(Zr0.51Ti0.49)0.98Nb0.02O3). It is shown that the usual macroscopic linear interpretation of the test can also be performed at the single crystal scale, allowing the identification of local apparent piezoelectric and elastic properties. It is also shown that despite this apparent linearity, the blocking force test involves significant non-linear behaviour mostly due to domain switching under electric field and stress. Although affecting a limited volume fraction of the material, domain switching is responsible for a large part of the macroscopic strain and explains the high level of inter- and intra-granular stresses observed during the course of the experiment. The study shows that if apparent piezoelectric and elastic properties can be identified for PZT single crystals from blocking stress curves, they may be very different from the actual properties of polycrystalline materials due to the multiplicity of the physical mechanisms involved. These apparent properties can be used for macroscopic modelling purposes but should be considered with caution if a local analysis is aimed at.

  2. Design and characterization of piezoelectric ultrasonic motors

    NASA Astrophysics Data System (ADS)

    Yener, Serra

    This thesis presents modeling and prototype fabrication and characterization of new types of piezoelectric ultrasonic micromotors. Our approach in designing these piezoelectric motors was: (i) to simplify the structure including the poling configuration of piezoelectric elements used in the stator and (ii) to reduce the number of components in order to decrease the cost and enhance the driving reliability. There are two different types of piezoelectric motors designed throughout this research. The first of these designs consists of a metal tube, on which two piezoelectric ceramic plates poled in thickness direction, were bonded. Two orthogonal bending modes of the hollow cylinder were superimposed resulting in a rotational vibration. Since the structure and poling configuration of the active piezoelectric elements used in the stator are simple, this motor structure is very suitable for miniaturization. Moreover, a single driving source can excite two bending modes at the same time, thus generate a wobble motion. Three types of prototypes are included in this design. The piezoelectric stator structure is the same for all. However, the dimensions of the motors are reduced by almost 50 percent. Starting with a 10 mm long stator, we reached to 4 mm in the last prototype. The initial diameter was 2.4 mm, which was reduced to 1.6 mm. In the final design, the rotor part of the motor was changed resulting in the reduction in the number of components. In terms of driving circuit, a single driving source was enough to run the motors and a conventional switching power supply type resonant L-C circuit was used. A simple motor structure with a simple driving circuit were combined successfully and fabricated inexpensively. The second design is a shear type piezoelectric linear motor. The behavior of a single rectangular piezoelectric shear plate was analyzed and after optimizing the dimensions and the mode characteristics, a prototype was fabricated. The prototype consists of one layer of ceramic and a brass teeth-like layer bonded on it. The displacement was amplified with the metal layer, the teeth of which were placed on the points of in-phase motion. The targeted application area is paper-feeding mechanism. In terms of application areas for the first design, a gas valve system and a micro vehicle were constructed. In addition, a new optical coherence tomography endoscope by utilizing the piezoelectric micromotor was designed. Finally, the prototype motor was integrated inside the camera of a cell phone to drive the zoom mechanism.

  3. First principles investigations of structural, elastic, dielectric and piezoelectric properties of { Ba,Sr,Pb } TiO3, { Ba,Sr,Pb } ZrO3 and { Ba,Sr,Pb } { Zr,Ti } O3 ceramics

    NASA Astrophysics Data System (ADS)

    Akgenc, Berna; Tasseven, Cetin; Cagin, Tahir

    2015-03-01

    We use first-principle density-functional study of structural, anisotropic mechanical, dielectric and piezoelectric properties of {Ba,Sr,Pb}TiO3, {Ba,Sr,Pb}ZrO3 and {Ba,Sr,Pb}{Zr,Ti}O3 alloys in cubic perovskite structures at zero temperature. Because there is significant interest in finding new piezoelectrics that do not contain toxic elements such as lead. In this study, we compare piezoelectric response of those alloys to synthesize outstanding piezoelectric materials. In perovskite structures, the spontaneous polarization is due to enormous values of Born effective charges computed by linear response within density functional perturbation theory, which are much larger than predicted nominal charge. We deeply investigated the effects of composition, order and site defects structure on piezoelectric constants.

  4. Consideration of Impedance Matching Techniques for Efficient Piezoelectric Energy Harvesting

    Microsoft Academic Search

    Hyeoungwoo Kim; Shashank Priya; Harry Stephanou; Kenji Uchino

    2007-01-01

    This study investigates multiple levels of impedance-matching methods for piezoelectric energy harvesting in order to enhance the conversion of mechanical to electrical energy. First, the transduction rate was improved by using a high piezoelectric voltage constant (g) ceramic material having a magnitude of g33 = 40 times 10-3 V m\\/N. Second, a transducer structure, cymbal, was optimized and fabricated to

  5. Fatigue and retention properties of shape memory piezoelectric actuator with non-180° domain switching

    NASA Astrophysics Data System (ADS)

    Kadota, Y.; Morita, T.

    2012-04-01

    A shape memory piezoelectric actuator can maintain a piezoelectric displacement without an operating voltage. It has two stable strain states at zero voltage: a poled state and a depoled state. The driving principle of the shape memory piezoelectric actuator is based on reorientation of the non-180° domains in the ferroelectric materials. In this study, a unimorph shape memory piezoelectric actuator with a soft lead zirconate titanate was fabricated. The fatigue and retention properties of this shape memory piezoelectric actuator were investigated. The fatigue behavior of the actuator in the early stages is considered to be closely related to the domain stabilization process. Continuous cycle fatigue tests revealed that the shape memory piezoelectric actuator continues to operate even after 106 cycles. Retention measurements revealed that the depoled state of the actuator was more stable than the poled state. The drift in the actuator displacement over one year was estimated to be less than 10% of the initial shape memory displacement.

  6. PIN-PMN-PT Single-Crystal-Based 1-3 Piezoelectric Composites for Ultrasonic Transducer Applications

    NASA Astrophysics Data System (ADS)

    Li, Lili; Xu, Zhuo; Xia, Song; Li, Zhengrong; Ji, Xuanrong; Long, Shaojun

    2013-08-01

    In this work, Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystal/epoxy 1-3 composites with different thicknesses (400 ?m to 825 ?m) were fabricated using the conventional dice-and-fill method. Their properties were compared with the corresponding lead zirconate titanate (PZT) ceramic 1-3 composites. Excellent properties for ultrasonic transducer applications have been achieved, such as high electromechanical coupling coefficient ( k t ? 78% to 83%), high piezoelectric strain coefficient ( d 33 ? 1000 pm/V), and lower acoustic impedance ( Z ? 20 Mrayl). The strain levels of PIN-PMN-PT composites were almost constant (1000 pm/V) with decreasing thickness, being much higher than those of PZT composites (650 pm/V). However, an increase in strain hysteresis was observed with decreasing thickness, reaching 25.3% for the 400- ?m single-crystal 1-3 composite, which is lower than the corresponding PZT composites (44.1% for 350- ?m PZT ceramic 1-3 composite). These results show that PIN-PMN-PT single-crystal 1-3 composites have great potential for use in advanced ultrasound transducer applications.

  7. From Titan’s tholins to Titan’s aerosols: Isotopic study and chemical evolution at Titan’s surface

    NASA Astrophysics Data System (ADS)

    Nguyen, Mai-Julie; Raulin, François; Coll, Patrice; Derenne, Sylvie; Szopa, Cyril; Cernogora, Guy; Israël, Guy; Bernard, Jean-Michel

    2008-07-01

    In the present work, we focused on the possible isotopic fractionation of carbon during the processes involved in the formation of Titan’s tholins. We present the first results obtained on the 12C/13C isotopic ratios measured on Titan’s tholins synthesized in laboratory with cold plasma discharges. Measurements of isotopic ratio 12C/13C, done both on tholins and on the initial gas mixture (N2:CH4 (98:2)) used to produce them, do not show any evident deficit or enrichment in 13C relatively to 12C in the synthesized tholins, compared to the initial gas mixture. This observation allows to go further in the analyses of the ACP experiment data, including part of the Cassini Huygens mission. We also focused on the chemical evolution of the aerosols at Titan surface by studying species coming from acid hydrolysis treatment of Titan’s tholins. Preliminary results show a wide diversity of chemical families, going from carboxylic acids to amino acids. Advanced studies could bring at short-term clues on the still unidentified mixture that induces the decrease of the reflectivity as measure by the DISR instrument [Tomasko, M.G., Archinal, B., Becker, T., Bézard, B., Bushroe, M., Combes, M., Cook, D., Coustenis, A., de Bergh, C., Dafoe, L.E., Doose, L., Douté, S., Eibl, A., Engel, S., Gliem, F., Grieger, B., Holso, K., Howington-Kraus, E., Karkoschka, E., Keller, H.U., Kirk, R., Kramm, R., Küppers, M., Lanagan, P., Lellouch, E., Lemmon, M., Lunine, J., McFarlane, E., Moores, J., Prout, G.M., Rizk, B., Rosiek, M., Rueffer, P., Schröder, S.E., Schmitt, B., See, C., Smith, P., Soderblom, L., Thomas, N., West, R. Rain, winds and haze during the Huygens probe’s descent to Titan’s surface. Nature 438(7069), 765 778, 2005]. At longer-term it could allow to better understand the possible chemical evolution of the Titan’s aerosols after falling down at the surface when brought into contact with water.

  8. Future Exploration of Titan

    NASA Astrophysics Data System (ADS)

    Lorenz, R. D.; Titan Decadal Panel Collaboration

    2001-11-01

    Titan promises to be the Mars of the Outer Solar System - the focus of not only the broadest range of investigations in planetary science but also the focus of public attention. The reasons for exploring Titan are threefold: 1. Titan and Astrobiology : Titan ranks with Mars and Europa as a prime body for astrobiological study due to its abundant organics. Like Europa, it may well have a liquid water interior. 2. Titan - A world in its own right. Titan deserves study even only to put other satellites (its remarkably smaller Saturnian siblings, and its same-sized but volatile-poor Jovian counterparts) in context. The added dimension of an atmosphere makes Titan's origin and evolution particularly interesting. 3. Titan - an environmental laboratory for Earth. Titan will be an unrivalled place to investigate meteorological, oceanographical and other processes. Many of these (e.g. wave generation by wind) are only empirically parameterized - the very different physical parameters of the Titan environment will bring new insights to these phenomena. While Cassini-Huygens will dramatically boost our knowledge of Titan, it will likely only whet our appetite for more. The potential for prebiotic materials at various locations (in particular where liquid water has interacted with photochemical deposits) and the need to monitor Titan's meteorology favor future missions that may exploit Titan's unique thick-atmosphere, low-gravity environment - a mobile platform like an airship or helicopter, able to explore on global scales, but access the surface for in-situ chemical analysis and probe the interior by electromagnetic and seismic means. Such missions have dramatic potential to capture the public's imagination, on both sides of the Atlantic.

  9. Ferroelectric electrooptic ceramics with reduced scattering

    Microsoft Academic Search

    P. D. Thacher; C. E. Land

    1969-01-01

    Ferroelectric lead zirconate-titanate ceramics appear promising for use as electrically controlled retarders because both conventional electrooptic and nonvolatile incremental retardation changes can be induced in areas as small as 25 µ on a side. One particular composition, Pb0.97La0.02Zr0.65Ti0.35O3, has so far proved superior to all other rhombohedral lead zirconate-titanates when judged by either the conventional electrooptic retardation variation with applied

  10. Electric-fieldtemperature phase diagram of the relaxor ferroelectric lanthanum-modified lead zirconate titanate

    E-print Network

    Bobnar, Vid

    ferroelectrics. S0163-1829 99 00233-7 I. INTRODUCTION Lanthanum-modified lead zirconate titanate ceramics Pb1 x than EC 5 kV/cm a long-range ferroelectric order is established in 9/65/35 PLZT ceramics. In particularElectric-field­temperature phase diagram of the relaxor ferroelectric lanthanum-modified lead

  11. Electrical poling below coercive field for large piezoelectricity

    NASA Astrophysics Data System (ADS)

    Guo, Hanzheng; Ma, Cheng; Liu, Xiaoming; Tan, Xiaoli

    2013-03-01

    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.

  12. Direct strain energy harvesting in automobile tires using piezoelectric PZT–polymer composites

    Microsoft Academic Search

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

    2012-01-01

    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

  13. Piezoelectric Nanoparticle-Polymer Composite Materials

    NASA Astrophysics Data System (ADS)

    McCall, William Ray

    Herein we demonstrate that efficient piezoelectric nanoparticle-polymer composite materials can be synthesized and fabricated into complex microstructures using sugar-templating methods or optical printing techniques. Stretchable foams with excellent tunable piezoelectric properties are created by incorporating sugar grains directly into polydimethylsiloxane (PDMS) mixtures containing barium titanate (BaTiO3 -- BTO) nanoparticles and carbon nanotubes (CNTs), followed by removal of the sugar after polymer curing. Porosities and elasticity are tuned by simply adjusting the sugar/polymer mass ratio and the electrical performance of the foams showed a direct relationship between porosity and the piezoelectric outputs. User defined 2D and 3D optically printed piezoelectric microstructures are also fabricated by incorporating BTO nanoparticles into photoliable polymer solutions such as polyethylene glycol diacrylate (PEGDA) and exposing to digital optical masks that can be dynamically altered. Mechanical-to-electrical conversion efficiency of the optically printed composite is enhanced by chemically altering the surface of the BTO nanoparticles with acrylate groups which form direct covalent linkages with the polymer matrix under light exposure. Both of these novel materials should find exciting uses in a variety of applications including energy scavenging platforms, nano- and microelectromechanical systems (NEMS/MEMS), sensors, and acoustic actuators.

  14. Synthesis of single-crystalline perovskite nanorods composed of barium titanate and strontium titanate.

    PubMed

    Urban, Jeffrey J; Yun, Wan Soo; Gu, Qian; Park, Hongkun

    2002-02-20

    We report the solution-based synthesis of single-crystalline nanorods composed of barium titanate (BaTiO3) and strontium titanate (SrTiO3), which yields well-isolated nanorods with diameters ranging from 5 to 60 nm and lengths reaching up to >10 mum. Electron microscopy and diffraction measurements show that these nanorods are composed of single-crystalline cubic perovskite BaTiO3 and SrTiO3 with a principal axis of the unit cell preferentially aligned along the wire length. These BaTiO3 and SrTiO3 nanorods should provide promising materials for fundamental investigations on nanoscale ferroelectricity, piezoelectricity, and paraelectricity. PMID:11841284

  15. Saturn Moons Explorer: Titan

    NSDL National Science Digital Library

    Only now are we beginning to learn about Titan, one of Saturn's most intriguing and enigmatic moons. This particular site provides an overview of Titan, courtesy of NASA's Jet Propulsion Laboratory, located at the California Institute of Technology. After watching an introductory video segment about Titan, visitors can learn more in the "Quick Facts" section. The "Latest Images" area contains twelve of the latest images of Titan as captured by the Cassini spacecraft. Visitors should also not miss the "3D Globe" area, which contains an interactive rendering of Titan which allows visitors to visit a number of features on this moon, including an ice volcano, drainage channels, and "The Smile", the brightest spot on Titan's surface.

  16. Titan Saturn System Mission

    NASA Technical Reports Server (NTRS)

    Reh, Kim R.

    2009-01-01

    Titan is a high priority for exploration, as recommended by NASA's 2006 Solar System Exploration (SSE) Roadmap. NASA's 2003 National Research Council (NRC) Decadal Survey and ESA's Cosmic Vision Program Themes. Recent revolutionary Cassini-Huygens discoveries have dramatically escalated interest in Titan as the next scientific target in the outer solar system. This study demonstrates that an exciting Titan Saturn System Mission (TSSM) that explores two worlds of intense astrobiological interest can be initiated now as a single NASA/ESA collaboration.

  17. Titanic: Discovery Channel

    NSDL National Science Digital Library

    RMS Titanic raised a 23- by 14-foot section of the Titanic's outer hull this week, and the Discovery Channel, who helped sponsor the expedition, will be webcasting live from the interior of the Titanic via robot cameras August 16 at 8:00 and 10:00 p.m. (Eastern Time). In addition to their live webcase, the Discovery Channel site (discussed in the December 5, 1997 issue of the Scout Report) features virtual reality tours of sections of the Titanic before and after its crash, quicktime videos of the expeditions, a computer animated simulation of the crash, and more.

  18. Multilayer modal actuator-based piezoelectric transformers.

    PubMed

    Huang, Yao-Tien; Wu, Wen-Jong; Wang, Yen-Chieh; Lee, Chih-Kung

    2007-02-01

    An innovative, multilayer piezoelectric transformer equipped with a full modal filtering input electrode is reported herein. This modal-shaped electrode, based on the orthogonal property of structural vibration modes, is characterized by full modal filtering to ensure that only the desired vibration mode is excited during operation. The newly developed piezoelectric transformer is comprised of three layers: a multilayered input layer, an insulation layer, and a single output layer. The electrode shape of the input layer is derived from its structural vibration modal shape, which takes advantage of the orthogonal property of the vibration modes to achieve a full modal filtering effect. The insulation layer possesses two functions: first, to couple the mechanical vibration energy between the input and output, and second, to provide electrical insulation between the two layers. To meet the two functions, a low temperature, co-fired ceramic (LTCC) was used to provide the high mechanical rigidity and high electrical insulation. It can be shown that this newly developed piezoelectric transformer has the advantage of possessing a more efficient energy transfer and a wider optimal working frequency range when compared to traditional piezoelectric transformers. A multilayer piezoelectric, transformer-based inverter applicable for use in LCD monitors or portable displays is presented as well. PMID:17328332

  19. Piezoelectricity and local structural distortions in (Na{sub 0.5}Bi{sub 0.5}){sub 1-x}Sr{sub x}TiO{sub 3}-Bi{sub 12}TiO{sub 20} flexoelectric-type polar ceramics

    SciTech Connect

    Wang, L. H.; Zhao, M. L.; Wang, C. L.; Wang, J.; Kuai, W. J.; Tao, X. T. [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China)

    2012-08-06

    We have previously described sintered Na{sub 0.5}Bi{sub 0.5}TiO{sub 3}-Bi{sub 12}TiO{sub 20} composites as flexoelectric-type polar ceramics because they have a net macroscopic flexoelectric polarization. Here, we report on the universal existence of the macroscopic flexoelectric polarization in the (Na{sub 0.5}Bi{sub 0.5}){sub 1-x}Sr{sub x}TiO{sub 3}-Bi{sub 12}TiO{sub 20} system, in which enhanced piezoelectricity is observed. By combining Raman spectroscopy and x-ray photoelectron spectroscopy techniques, we have identified the local flexoelectric polarization as distorted BiO{sub 5} polyhedra and TiO{sub 6} octahedra in the SrTiO{sub 3}-Bi{sub 12}TiO{sub 20} ceramic. The macroscopic polarization may be due to the partial alignment of these distorted units located within the grain boundary amorphous phases. Bi{sub 12}TiO{sub 20} could have an important role in these flexoelectric-type polar ceramics.

  20. Influence of crystallization on strength and color of castable glass-ceramics containing two crystals.

    PubMed

    Tada, Y; Kawano, F; Kon, M; Matsumoto, N; Asaoka, K

    1995-01-01

    The mechanical properties, color and transparency of glass-ceramics are highly dependent on the ceramming temperature and/or amount of the crystal phase in the glass matrix. In this study, the influence of crystallization on the strength and color, translucency of castable ceramics containing crystalline apatite and magnesium titanate were measured. It was concluded that magnesium titanate precipitated during ceramming, appeared to be an important factor in decreasing total transmittance and in determination of the color of glass-ceramics. PMID:8785508

  1. Titan's surface before Cassini

    Microsoft Academic Search

    Ralph D. Lorenz; Jonathan I. Lunine

    2005-01-01

    We review current understanding of Titan's surface, synthesizing a paradigm from Earth-based radar observations and near-infrared surface maps, together with reanalysis of Voyager data and results from published theoretical models. Based on these we suggest that Titan has a varied landscape with a variety of tectonic and erosive features indicative of geologic activity, and an impact crater population reflective of

  2. Cassini Titan Radar Mapper

    Microsoft Academic Search

    CHARLES ELACHI; E. Im; L. E. Roth; C. L. Werner

    1991-01-01

    The Cassini Titan Radar Mapper is a multimode radar instrument designed to probe the optically inaccessible surface of Titan, Saturn's largest moon. The instrument is to be included in the payload of the Cassini Saturn Mission, scheduled for launch in 1995. The individual modes of Cassini Radar Mapper will allow topographic mapping and surface imaging at few hundred meters resolution.

  3. Low Temperature Sintering and Piezoelectric Properties in Pb(ZrxTi1-x)O3-Pb(Zn1/3Nb2/3)O3-Pb(Ni1/3Nb2/3)O3 Ceramics

    NASA Astrophysics Data System (ADS)

    Ahn, Cheol-Woo; Song, Hyun-Cheol; Park, Seung-Ho; Nahm, Sahn; Uchino, Kenji; Priya, Shashank; Lee, Hyeung-Gyu; Kang, Nam-Kee

    2005-03-01

    High-power ceramics of the composition 0.8Pb(Zr0.5Ti0.5)O3-0.2Pb[(Zn0.8Ni0.2)1/3Nb2/3]O3 (0.8PZT-0.2PZNN) + 0.5 wt% MnO2 have excellent piezoelectric and dielectric properties such as d33=320 pC/N, {\\varepsilon33}T/\\varepsilono=1227, kp=0.54, and Qm=1265. However, the sintering temperature of this composition is high, approximately 1200°C, restricting the use of cheap base metal electrodes in the fabrication of multilayer components. In this study, we provide a solution to this problem and report a low sintering temperature high-power composition in a PZT-PZNN system. CuO and Al2O3 were selected as sintering agents. It was found that the addition of CuO can reduce the sintering temperature to 920°C, but it can also significantly reduce the piezoelectric properties. The reduction of Qm magnitude was 81% when 0.5 wt% CuO was added. The addition of Al2O3 as a sintering agent was found to improve Qm magnitude but significant reductions in piezoelectric and dielectric properties were observed. The addition of excess ZnO and NiO was found to improve the density and piezoelectric properties, but it was also found to reduce Qm magnitude. Consequently, the optimization of the concentration of the sintering agents was carried out, and the optimized low sintering temperature high-power composition was found to be 0.875Pb(Zr0.5Ti0.5)O3-0.125Pb[(Zn0.8Ni0.2)1.5/3Nb2/3]O3 + 0.5 wt% MnO2 + 0.2 wt% CuO + 0.3 wt% Al2O3. The piezoelectric properties of the specimens of this composition sintered at 920°C were found to be kp=0.581, Qm=809, d33=345 pC/N, {\\varepsilon3}T/\\varepsilono=1345, and Tc=330°C.

  4. Pyroelectric energy conversion using PLZT ceramics and the ferroelectricergodic relaxor phase transition

    E-print Network

    Pilon, Laurent

    Pyroelectric energy conversion using PLZT ceramics and the ferroelectric­ergodic relaxor phase conversion using PLZT ceramics and the ferroelectric­ergodic relaxor phase transition Felix Y Lee, Hwan Ryul titanate (PLZT) ceramics undergoing a relaxor­ferroelectric phase transition. The Olsen cycle consists

  5. Lifetime of ferroelectric Pb,,Zr,Ti...O3 ceramic cathodes with high current density

    E-print Network

    Jerby, Eli

    Lifetime of ferroelectric Pb,,Zr,Ti...O3 ceramic cathodes with high current density M. Einat, D-titanate ceramic cathode with composition related to a ferroelectric phase was studied. The strong plasma emission with classical electron sources. In 1993 destruction of electrodes and ferroelectric ceramics of cathodes

  6. Titan's Methane Weather

    NASA Astrophysics Data System (ADS)

    Roe, Henry G.

    2012-05-01

    Conditions in Titan's troposphere are near the triple point of methane, the second most abundant component of its atmosphere. Our understanding of Titan's lower atmosphere has shifted considerably in the past decade. Ground-based observations, Hubble Space Telescope images, and data returned from the Cassini and Huygens spacecraft show that Titan's troposphere hosts a methane-based meteorology in direct analogy to the water-based meteorology of Earth. What once was thought to be a quiescent place, lacking in clouds or localized weather and changing only subtly on long seasonal timescales, is now understood to be a dynamic system with significant weather events regularly occurring against the backdrop of dramatic seasonal changes. Although the observational record of Titan's weather covers only a third of its 30-year seasonal cycle, Titan's atmospheric processes appear to be more closely analogous to those of Earth than to those of any other object in our solar system.

  7. Fabrication and Basic Characterization of a Piezoelectric Valveless Micro Jet Pump

    Microsoft Academic Search

    Katsuhiko Tanaka; Van Thanh Dau; Ryohei Sakamoto; Thien Xuan Dinh; Dzung Viet Dao; Susumu Sugiyama

    2008-01-01

    A piezoelectric-driven valveless micro jet pump with a novel channel structure has been designed and fabricated. The simple structure micro jet pump consists of a lead zirconate titanate (PZT) diaphragm and flow channels. The design of the flow channels focuses on a cross junction formed by the neck of the pump chamber and one outlet and two opposite inlet channels.

  8. High-sensitivity accelerometer composed of ultra-long vertically aligned barium titanate nanowire arrays

    NASA Astrophysics Data System (ADS)

    Koka, Aneesh; Sodano, Henry A.

    2013-11-01

    A configuration that shows great promise in sensing applications is vertically aligned piezoelectric nanowire arrays that allow facile interfacing with electrical interconnects. Nano-electromechanical systems developed using piezoelectric nanowires have gained interest primarily for their potential in energy harvesting applications, because they are able to convert several different sources of mechanical energy into useful electrical power. To date, no results have demonstrated the capability to use aligned piezoelectric nanowire arrays as a highly accurate nano-electromechanical system based dynamic sensor with a wide operating bandwidth and unity coherence. Here we report the growth of vertically aligned (~45 ?m long) barium titanate nanowire arrays, realized through a two-step hydrothermal synthesis approach, and demonstrate their use as an accurate accelerometer. High sensitivity of up to 50?mV?g-1 is observed from the sensor composed of vertically aligned barium titanate nanowire arrays, thus providing performance comparable to many of the commercial accelerometer systems.

  9. Piezoelectric micromachined microphones with out-of-plane directivity

    NASA Astrophysics Data System (ADS)

    Kim, Donghwan; Hewa-Kasakarage, Nishshanka N.; Kuntzman, Michael L.; Kirk, Karen D.; Yoon, Sang H.; Hall, Neal A.

    2013-07-01

    Piezoelectric microphones with out-of-plane directivity are introduced. Structures are comprised of circular diaphragms suspended on compliant circumferential springs and open to ambient at front and back sides. The springs contain thin piezoelectric films for integrated piezoelectric readout. Prototypes are presented in which diaphragm and springs are etched into a 10-?m-thick epitaxial Si layer with 800-nm-thick lead-zirconate-titanate films on the spring surface. Directivity and frequency response measurement confirm anticipated device functionality. A discussion of signal-to-noise ratio (SNR) merits of the approach is presented, concluding that up to 20-dB SNR improvements may be possible beyond what is achievable with present state-of-the-art commercial microphones.

  10. Effective dielectric and elastic constants of piezoelectric polycrystals

    NASA Astrophysics Data System (ADS)

    Olson, Tamara; Avellaneda, Marco

    1992-05-01

    The effective dielectric constant, bulk modulus, and shear modulus of isotropic polycrystals with piezoelectric grains are studied using an effective medium approximation (EMA) and generalized Hashin-Shtrikman bounds. The EMA determines self-consistently the electromechanical interaction of grains with the surrounding composite. Numerical values for the moduli are computed for barium titanate and compared with available experimental data, as well as with classical estimates for the moduli. Further assessment of the EMA is made by computing numerical values of the effective moduli for ideal polycrystals, based on numerical data for crystals with strong piezoelectric coupling and comparing the resulting values with classical estimates. Similar comparisons are made for the generalized Hashin-Shtrikman bounds. On 'ideal' polycrystals the gap between the upper and lower bounds can be 30 percent narrower than the corresponding gap if piezoelectric coupling is neglected.

  11. Thermal deformation compensation of a composite beam using piezoelectric actuators

    Microsoft Academic Search

    G. Song; X. Zhou; W. Binienda

    2004-01-01

    Maintaining the surface shape of precision structures such as spacecraft antenna reflectors has been a challenging task. Surface errors are often introduced by thermal distortions due to temperature differences. This paper presents numerical and experimental results of active compensation of thermal deformation of a composite beam using piezoelectric ceramic actuators. To generate thermal distortion of the composite beam, two film

  12. Thermal deformation compensation of a composite beam using piezoelectric actuators

    Microsoft Academic Search

    Xiaoqin Zhou; Gangbing Song; W. Binienda

    2002-01-01

    Maintaining surface shape of precision structures such as spacecraft antenna reflectors has been a challenging task. The surface errors are often introduced by thermal distortions due to temperature differences. This paper presents numerical and experimental results of active compensation of thermal deformation of a composite beam using piezoelectric ceramic actuators. To generate thermal distortion to the composite beam, two film

  13. Piezoelectric Energy Harvesting under High PreStressed Cyclic Vibrations

    Microsoft Academic Search

    Hyeoung Woo Kim; Shashank Priya; Kenji Uchino; Robert E. Newnham

    2005-01-01

    Cymbal transducers have been found as a promising structure for piezoelectric energy harvesting under high force (? 100 N) at cyclic conditions (? 100–200 Hz). The thicker steel cap enhances the endurance of the ceramic to sustain higher ac loads along with stress amplification. This study reports the performance of the cymbal transducer under ac force of 70 N with

  14. The evolution of the Titan rocket - Titan I to Titan II

    NASA Astrophysics Data System (ADS)

    Adams, Laurence J.

    1990-10-01

    The Titan I and Titan II rockets are described. The designs of the stages, test stands, and basing systems are considered, and the developmental history of each rocket is briefly recapitulated. The ways in which Titan II represents an evolution from Titan I are pointed out.

  15. Aerosol growth in Titan’s ionosphere

    PubMed Central

    Lavvas, Panayotis; Yelle, Roger V.; Koskinen, Tommi; Bazin, Axel; Vuitton, Véronique; Vigren, Erik; Galand, Marina; Wellbrock, Anne; Coates, Andrew J.; Wahlund, Jan-Erik; Crary, Frank J.; Snowden, Darci

    2013-01-01

    Photochemically produced aerosols are common among the atmospheres of our solar system and beyond. Observations and models have shown that photochemical aerosols have direct consequences on atmospheric properties as well as important astrobiological ramifications, but the mechanisms involved in their formation remain unclear. Here we show that the formation of aerosols in Titan’s upper atmosphere is directly related to ion processes, and we provide a complete interpretation of observed mass spectra by the Cassini instruments from small to large masses. Because all planetary atmospheres possess ionospheres, we anticipate that the mechanisms identified here will be efficient in other environments as well, modulated by the chemical complexity of each atmosphere. PMID:23382231

  16. Phase transitions of low-temperature sintering tungsten-doped ZnO-TiO 2 ceramics

    Microsoft Academic Search

    Xiangchun Liu; Feng Gao; Lili Zhao; Changsheng Tian

    2007-01-01

    WO3-doped zinc titanate ceramics were prepared by conventional mixed-oxide method combined with a chemical processing. The effects\\u000a of WO3 addition on the low-temperature sintering behavior, phase transition and dielectric properties of zinc titanate ceramics\\u000a were investigated. The results show that the densification temperature of ZnTiO3 ceramics can be reduced from 1150 to 900 °C with WO3 addition and chemical processing. Small

  17. High thermal stability of piezoelectric properties in (Na{sub 0.5}Bi{sub 0.5}TiO{sub 3}){sub x}-(BaTiO{sub 3}){sub y}-(Na{sub 0.5}K{sub 0.5}NbO{sub 3}){sub 1-x-y} ceramics

    SciTech Connect

    Gupta, Shashaank; Priya, Shashank [Bio-Inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Bio-Inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2013-01-07

    We report the piezoelectric and ferroelectric properties of (Na{sub 0.5}Bi{sub 0.5}TiO{sub 3}){sub x}-(BaTiO{sub 3}){sub y}-(Na{sub 0.5}K{sub 0.5}NbO{sub 3}){sub 1-x-y} ceramics for Na{sub 0.5}K{sub 0.5}NbO{sub 3} rich end of composition (x, y {<=} 0.04 mol. %). These compositions were found to exhibit significantly improved thermal stability of piezoresponse. Variation of dielectric constant as a function of temperature revealed that orthorhombic-tetragonal (T{sub o-t}) and tetragonal-cubic (T{sub c}) transition temperatures for these compositions were in the vicinity of 0 Degree-Sign C and 330 Degree-Sign C, respectively. Dynamic scaling and temperature dependent X-ray diffraction analysis were conducted. Results are discussed in terms of intrinsic and extrinsic contributions to the piezoelectric response explaining the temperature dependent behavior.

  18. Characterization of piezoelectric paint and its refinement for structural health monitoring applications

    NASA Astrophysics Data System (ADS)

    Yang, Cheng; Fritzen, Claus-Peter

    2012-04-01

    Piezoelectric paint is a composite piezoelectric material, due to its outstanding properties consisting of flexibility and conformability, it has been a great interest in structural health monitoring applications recently. The normal piezoelectric ceramics offer high piezoelectric properties, but are difficult to adhere on curly structural surfaces. For normal polymers, it offers high flexibility but missing the ability to transform the mechanical energy into the electrical energy, and vice versa. The piezoelectric paint combines the features of both, so it could be distributed on both even and uneven structural surface, as a sensor or actuator. This work starts with the development of the piezoelectric paint, followed by a systematic characterization of its mechanical and piezoelectric properties, which includes microstructure, Young's modulus, sensitivity and piezoelectric charge constant da1. The characterization results helps to understand the performance of the piezoelectric paint more deeply. Finally, a refinement method is demonstrated to improve the piezoelectricity of the paint. The results showed that the piezoelectricity was greatly improved and therefore its applications in structural health monitoring is widely expanded.

  19. Characterization of piezoelectric paint and its refinement for structural health monitoring applications

    NASA Astrophysics Data System (ADS)

    Yang, Cheng; Fritzen, Claus-Peter

    2011-11-01

    Piezoelectric paint is a composite piezoelectric material, due to its outstanding properties consisting of flexibility and conformability, it has been a great interest in structural health monitoring applications recently. The normal piezoelectric ceramics offer high piezoelectric properties, but are difficult to adhere on curly structural surfaces. For normal polymers, it offers high flexibility but missing the ability to transform the mechanical energy into the electrical energy, and vice versa. The piezoelectric paint combines the features of both, so it could be distributed on both even and uneven structural surface, as a sensor or actuator. This work starts with the development of the piezoelectric paint, followed by a systematic characterization of its mechanical and piezoelectric properties, which includes microstructure, Young's modulus, sensitivity and piezoelectric charge constant da1. The characterization results helps to understand the performance of the piezoelectric paint more deeply. Finally, a refinement method is demonstrated to improve the piezoelectricity of the paint. The results showed that the piezoelectricity was greatly improved and therefore its applications in structural health monitoring is widely expanded.

  20. Overview of multilayer ceramic actuator program at C-MET

    Microsoft Academic Search

    N. Raghu; V. Kumar; K. R. Dayas; I. C. Rao

    2003-01-01

    One of the major programs being undertaken in our unit is, development of actuator materials and conversion of these materials into multilayer actuator devices. In order to achieve this objective, development of piezoelectric and electrostrictive materials are also being attempted. A simple and novel chemical precipitation route has been adopted for the synthesis of nano-actuator materials. Lead Zirconate Titanate (PZT)

  1. PIEZOELECTRIC POWER SCAVENGING OF MECHANICAL VIBRATION ENERGY

    E-print Network

    Ervin, Elizabeth K.

    with other smart materials for power harvesting #12;Piezoelectric MaterialsPiezoelectric MaterialsPIEZOELECTRIC POWER SCAVENGING OF MECHANICAL VIBRATION ENERGY PIEZOELECTRIC POWER SCAVENGING and magneticand magnetic field.field. Piezoelectric Materials as Smart Material- Among the all smart materials

  2. Titan's organic chemistry

    NASA Technical Reports Server (NTRS)

    Sagan, C.; Thompson, W. R.; Khare, B. N.

    1985-01-01

    Voyager discovered nine simple organic molecules in the atmosphere of Titan. Complex organic solids, called tholins, produced by irradiation of the simulated Titanian atmosphere, are consistent with measured properties of Titan from ultraviolet to microwave frequencies and are the likely main constituents of the observed red aerosols. The tholins contain many of the organic building blocks central to life on earth. At least 100-m, and possibly kms thicknesses of complex organics have been produced on Titan during the age of the solar system, and may exist today as submarine deposits beneath an extensive ocean of simple hydrocarbons.

  3. Ceramic - Polymer Nanocomposite: Alternate Choice of Bone (Review)

    Microsoft Academic Search

    Debasish Sarkar; Min Cheol Chu; Seong Jai Cho

    This study evaluates a range of materials that may be used to design prostheses for bone. It is found that nanocrystalline ceramic-polymer composite could be the best material for prosthetic bone with respect to biocompatibility, morphology, chemistry, and compatibility with the piezoelectric and mechanical behavior of long human bones, such as the femur. Keyword: Bone, Prosthesis, Nanocomposite, Ceramic, Polymer

  4. Design and analysis of a piezoelectric material based touch screen with additional pressure and its acceleration measurement functions

    NASA Astrophysics Data System (ADS)

    Chu, Xiang-Cheng; Liu, Jia-Yi; Gao, Ren-Long; Chang, Jie; Li, Long-Tu

    2013-12-01

    Touch screens are becoming more and more prevalent in everyday environments due to their convenience and humanized operation. In this paper, a piezoelectric material based touch screen is developed and investigated. Piezoelectric ceramics arrayed under the touch panel at the edges or corners are used as tactile sensors to measure the touch positioning point similarly to conventional touch screens. However, additional touch pressure and its acceleration performance can also be obtained to obtain a higher-level human-machine interface. The piezoelectric ceramics can also be added to a traditional touch screen structure, or they can be used independently to construct a novel touch screen with a high light transmittance approach to a transparent glass. The piezoelectric ceramics were processed from PZT piezoelectric ceramic powder into a round or rectangular shape. According to the varied touch position and physical press strength of a finger, or even a gloved hand or fingernail, the piezoelectric tactile sensors will have different output voltage responses. By calculating the ratio of different piezoelectric tactile sensors’ responses and summing up all piezoelectric tactile sensors’ output voltages, the touch point position, touch pressure and touch force acceleration can be detected. A prototype of such a touch screen is manufactured and its position accuracy, touch pressure and response speed are measured in detail. The experimental results show that the prototype has many advantages such as high light transmittance, low energy cost and high durability.

  5. Centrifugal Jet Spinning for Highly Efficient and Large-scale Fabrication of Barium Titanate Nanofibers

    PubMed Central

    Ren, Liyun; Kotha, Shiva P.

    2014-01-01

    The centrifugal jet spinning (CJS) method has been developed to enable large-scale synthesis of barium titanate nanofibers. Barium titanate nanofibers with fiber diameters down to 50 nm and grain sizes around 25 nm were prepared with CJS by spinning a sol-gel solution of barium titanate and poly(vinylpyrrolidone) with subsequent heat treatment at 850 °C. XRD and FTIR analysis demonstrated high purity and tetragonal perovskite structured barium titanate nanofibers. SEM and TEM images confirm the continuous high aspect ratio structure of barium titanate nanofibers after heat treatment. It is demonstrated that the CJS technique offers a highly efficient method for large-scale fabrication of ceramic nanofibers at production rates of up to 0.3 gram/minute. PMID:24563566

  6. The TITAN reversed-field-pinch fusion reactor study

    SciTech Connect

    Not Available

    1990-01-01

    This report discusses the following topics: overview of titan-2 design; titan-2 fusion-power-core engineering; titan-2 divertor engineering; titan-2 tritium systems; titan-2 safety design and radioactive-waste disposal; and titan-2 maintenance procedures.

  7. Design and processing of multi-layered flextensional piezoelectric actuators

    NASA Astrophysics Data System (ADS)

    Vartuli, James Scott

    Piezoelectric actuators are unique to other actuator systems due to their fast response time (˜10-4 s) and displacement accuracy on the order of a nanometer. Piezoelectric strain is obtained with the application of an electric field. Useful applications include adaptive optical systems and active vibration dampening. One type of piezoelectric actuator is the flextensional device, which requires a gradient in electromechanical properties to create a bending moment through non-uniform lateral stresses. The simplest flextensional device, called the unimorph, is a piezoelectric bonded to a metal plate. The bond between piezoelectric and metal is subjected to stresses that can lead to lifetime limitations. Fabrication requires cutting, polishing, and bonding, which does not facilitate miniaturization and curved shell structures. The monomorph and RAINBOW are modifications of the unimorph that seek to improve upon these drawbacks. The monomorph is comprised of one plate of normally insulating piezoelectric that is made semiconductive with a dopant. With an applied field, a non-uniform electric-field distribution arises due to the semiconductor-electrode interface. Removal of the difficult tasks of surface preparation and bonding are processing advantages that better enable component miniaturization. RAINBOW removes potential interface problems of bonding dissimilar materials together by creating a metal-ceramic layer within the piezoelectric ceramic by chemically reducing the oxygen content. The processing methods of the monomorph and RAINBOW are limited since they can only create one functional gradient. Our work sought to create a modification of the unimorph with the capability for miniaturization while maintaining the positive attributes of the previously mentioned technologies. Called PrinDrex, named for the collaborative effort between Princeton and Drexel Universities, we construct functional gradients by layering different ceramic-polymer tapes in an appropriate order. We construct 'custom-made' actuators by layering ceramics with different piezoelectric constants and electrical properties. After sintering this fully ceramic laminate only requires electrode application and poling to function. No post-sintering steps are required, which better enables the fabrication of large and small devices. PrinDrex is capable of generating displacements and forces equivalent to the best commercially available flextensional devices. We characterized with electron microscopy and modeled and predicted actuator performance with finite element analysis.

  8. Measurement of effective piezoelectric coefficients of PZT thin films for energy harvesting application with interdigitated electrodes.

    PubMed

    Chidambaram, Nachiappan; Mazzalai, Andrea; Muralt, Paul

    2012-08-01

    Interdigitated electrode (IDE) systems with lead zirconate titanate (PZT) thin films play an increasingly important role for two reasons: first, such a configuration generates higher voltages than parallel plate capacitor-type electrode (PPE) structures, and second, the application of an electric field leads to a compressive stress component in addition to the overall stress state, unlike a PPE structure, which results in tensile stress component. Because ceramics tend to crack at relatively moderate tensile stresses, this means that IDEs have a lower risk of cracking than PPEs. For these reasons, IDE systems are ideal for energy harvesting of vibration energy, and for actuators. Systematic investigations of PZT films with IDE systems have not yet been undertaken. In this work, we present results on the evaluation of the in-plane piezoelectric coefficients with IDE systems. Additionally, we also propose a simple and measurable figure of merit (FOM) to analyze and evaluate the relevant piezoelectric parameter for harvesting efficiency without the need to fabricate the energy harvesting device. Idealized effective coefficients e(IDE) and h(IDE) are derived, showing its composite nature with about one-third contribution of the transverse effect, and about two-thirds contribution of the longitudinal effect in the case of a PZT film deposited on a (100)-oriented silicon wafer with the in-plane electric field along one of the <011> Si directions. Randomly oriented 1-?m-thick PZT 53/47 film deposited by a sol-gel technique, was evaluated and yielded an effective coefficient e(IDE) of 15 C·m(-2). Our FOM is the product between effective e and h coefficient representing twice the electrical energy density stored in the piezoelectric film per unit strain deformation (both for IDE and PPE systems). Assuming homogeneous fields between the fingers, and neglecting the contribution from below the electrode fingers, the FOM for IDE structures with larger electrode gap is derived to be twice as large as for PPE structures, for PZT-5H properties. The experiments yielded an FOM of the IDE structures of 1.25 × 10(10) J/m(3) and 14 mV/? strain. PMID:22899110

  9. Raising the Titanic.

    ERIC Educational Resources Information Center

    Baker, Romona

    1990-01-01

    Described is an activity in which groups of students investigate engineering principles by writing a feasibility study to raise the luxury liner, Titanic. The problem statement and directions, and suggestions for problem solutions are included. (CW)

  10. Kelvin and piezoelectricity

    NASA Astrophysics Data System (ADS)

    Trainer, Matthew

    2003-09-01

    This paper presents a résumé of the history of piezoelectricity during the 19th and 20th centuries. By examining the experiments, concepts and theories presented in Lord Kelvin's scientific communications and those of his contemporaries, this paper aims to show that he played an important role in the development of piezoelectricity. Kelvin's contribution was that he produced the measurement instrumentation that led to the discovery of piezoelectricity and laid some of the essential theoretical groundwork that led to the important applications of piezoelectricity in the 20th century.

  11. Lead zirconate titanate-based thick films for high-frequency focused ultrasound transducers prepared by electrophoretic deposition.

    PubMed

    Abellard, André-Pierre; Kuscer, Danjela; Grégoire, Jean-Marc; Lethiecq, Marc; Malic, Barbara; Levassort, Franck

    2014-03-01

    An electrophoretic deposition (EPD) process with high deposition rate was used to fabricate a curved piezoelectric thick film devoted to high-frequency transducers for medical imaging. Niobium-doped lead zirconate titanate (PZTNb) powder was stabilized in ethanol to prepare a suspension with high zeta potential and low conductivity. A gold layer, pad-printed and fired on a curved porous PZT substrate, was used as the working electrode for the deposition of the PZTNb thick film. This substrate was chosen because it has the required properties (acoustic impedance and attenuation) to be used directly as a backing for the high-frequency transducer, leading to a simplified process for transducer assembly with this integrated structure. PZT-Nb thick films were also deposited by EPD on flat gold-coated alumina substrates as a reference. The thickness of the films was between 20 and 35 ?m, and their electromechanical performance was comparable to standard PZT bulk ceramics with a thickness coupling factor of 48%. For the curved thick film, the thickness coupling factor was slightly lower. The corresponding integrated structure was used to fabricate a transducer with a center frequency of 40 MHz and an f-number of 2.8. It was integrated into a realtime ultrasound scanner and used to image human forearm skin; the resulting images showed, for the first time, the efficacy of the EPD process for these imaging applications. PMID:24569258

  12. Titan - Some new results

    NASA Astrophysics Data System (ADS)

    Owen, T.; Gautier, D.

    New analyses of Voyager spectra of Titan have led to improvements in the determination of abundances of minor constituents as a function of latitude and altitude. Ground-based microwave observations have extended the Voyager results for HCN, and have demonstrated that CO is mysteriously deficient in the stratosphere. The origin of the CH4, CO, and N2 in Titan's atmosphere is still unresolved. Both primordial and evolutionary sources are compatible with the available evidence.

  13. Titan's Ammonia Feature

    NASA Technical Reports Server (NTRS)

    Smythe, W.; Nelson, R.; Boryta, M.; Choukroun, M.

    2011-01-01

    NH3 has long been considered an important component in the formation and evolution of the outer planet satellites. NH3 is particularly important for Titan, since it may serve as the reservoir for atmospheric nitrogen. A brightening seen on Titan starting in 2004 may arise from a transient low-lying fog or surface coating of ammonia. The spectral shape suggests the ammonia is anhydrous, a molecule that hydrates quickly in the presence of water.

  14. Preparation of Lead Zirconate Titanate (Pb(Zr0.52Ti0.48)O3) by Homogeneous Precipitation and Calcination

    E-print Network

    Tas, A. Cuneyt

    Preparation of Lead Zirconate Titanate (Pb(Zr0.52Ti0.48)O3) by Homogeneous Precipitation-ray spectroscopy (EDXS). I. Introduction LEAD ZIRCONATE TITANATE (PbZrxTi1-xO3) ceramics are of great technological by a semiwet procedure. In the present study, the experimental details of the synthesis of lead zirconate

  15. Dielectric and ferroelectric analysis of nanoparticle/nanocrystalline barium titanate and PLZT.

    SciTech Connect

    DiAntonio, Christopher Brian; Yang, Pin; Chavez, Tom P.; Winter, Michael R.; Monson, Todd C.; Roesler, Alexander William

    2010-07-01

    Attractive for numerous technological applications, ferroelectronic oxides constitute an important class of multifunctional compounds. Intense experimental efforts have been made recently in synthesizing, processing and understanding ferroelectric nanostructures. This work will present the systematic characterization and optimization of barium titanate and lead lanthanum zirconate titanate nanoparticle based ceramics. The nanoparticles have been synthesized using several solution and pH-based synthesis processing routes and employed to fabricate polycrystalline ceramic and nanocomposite based components. The dielectric and ferroelectric properties of these various components have been gauged by impedance analysis and electromechanical response and will be discussed.

  16. Fabrication and Electrical Properties of Potassium Niobate Ferroelectric Ceramics

    Microsoft Academic Search

    Hajime Nagata; Kenji Matsumoto; Tadayuki Hirosue; Yuji Hiruma; Tadashi Takenaka

    2007-01-01

    Potassium niobate, KNbO3 (KN), ceramics were prepared by a modified conventional ceramic fabrication process to characterize their piezoelectric properties. The modified process involving two-stage calcination (first stage at 600 °C and second stage at 1000 °C) is very effective in obtaining KN ceramics with a high density ratio >96% and a high resistivity, rho, of >1012 Omega\\\\cdotcm and that are

  17. THE APPLICATION OF HIGH ENERGY ELECTRIC AND MAGNETIC FIELDS TO PROCESS FLY ASH AND CERAMICS. MISA 2004

    Microsoft Academic Search

    M. La Robina; J. Ferenczy

    ANSTO's development of waste forms for nuclear waste has lead to the development of equipment and methodologies that allow us to control the properties of materials like titanate ceramics. The complex compositions of waste streams in the nuclear industry have resulted in the design of a wide range of chemical compositions of ceramics, glass and glass- ceramics to immobilize specific

  18. Titan’s atmosphere from ISO mid-infrared spectroscopy

    Microsoft Academic Search

    Athena Coustenis; A. Salama; B. Schulz; S. Ott; E. Lellouch; T. h Encrenaz; D. Gautier; H. Feuchtgruber

    2003-01-01

    We have analyzed Titan observations performed by the Infrared Space Observatory (ISO) in the range 7–30 ?m. The spectra obtained by three of the instruments on board the mission (the short wavelength spectrometer, the photometer, and the camera) were combined to provide new and more precise thermal and compositional knowledge of Titan’s stratosphere. With the high spectral resolution achieved by

  19. Piezoelectric energy harvesting

    Microsoft Academic Search

    Christopher A Howells

    2009-01-01

    Piezoelectric materials can be used to convert oscillatory mechanical energy into electrical energy. This technology, together with innovative mechanical coupling designs, can form the basis for harvesting energy from mechanical motion. Piezoelectric energy can be harvested to convert walking motion from the human body into electrical power. Recently four proof-of-concept Heel Strike Units were developed where each unit is essentially

  20. Light Controlled Piezoelectric Transformer

    Microsoft Academic Search

    Lucjan Kozielski

    2011-01-01

    The author designed ``smart material'' device allow to control an output voltage level by change of incident light intensity. New functions of piezoelectric transformer (PT) was realized by superimposing piezoelectricity with photostriction. The effect of a light influence on the PT voltage gain was proved experimentally, consequently these ``smart'' transformers with its new functionality can be utilized as a promising

  1. Titan's impact history

    NASA Astrophysics Data System (ADS)

    Zahnle, Kevin

    2010-04-01

    Impacts play a major role in the growth and evolution of planets, satellites, and other nameless things. Titan is no exception. This talk will address a subset of the following topics: (i) The modern impact rate is constrained by the population of Centaurs and the impact rate at Jupiter. (ii) Titan's thick atmosphere and volatile surface cause it to respond to major impacts in an Earth-like manner. The impact that made Menrva - the 440 km diameter impact basin sited near the current apex of Titan's motion - was big enough to raise the average global surface temperature above 273 K, which suggests that water rain was possible. This would have been followed by methane drizzles lasting for thousands of years. More modest impacts will generate crater lakes and will saturate the atmosphere with methane, the latter leading to hundreds of years of intermittent drizzle. (iii) Impact ejecta from Menrva will strike Hyperion and should saturate the latter with sesquinary craters. (iv) In any modern story of how Titan got its atmosphere, solar nebular condensates (comets) deliver the volatiles. A consequence of a cometogenic atmosphere is that the atmosphere is heavily processed by strong shocks. The high temperatures produce a wide range of chemical species that would not otherwise be abundant. Some of these will survive to mix into the atmosphere (e.g., CO) or freeze out to fall to the surface (e.g. CO2). (v) That Titan even has an atmosphere, when Callisto and Ganymede do not, is an excellent question. The leading explanation is that Titan alone was made from ammonia - and methane - rich stuff. But the competition between impact delivery and impact expulsion of volatiles can strongly favor Titan over Callisto. Stable isotopes as well as total volatile inventories provide constraints.

  2. Inorganic ceramic\\/polymer ferroelectric composite electrets

    Microsoft Academic Search

    C. J. Dias; D. K. Das-Gupta

    1996-01-01

    Ferroelectric composites are now an established alternative to conventional ferroelectric ceramic materials and to the more recently discovered ferroelectric polymers. These materials due to their unique blending of polymetric properties of mechanical flexibility, formability and low cost with high electro-active properties have been been suggested to be a viable alternative both in piezoelectric and pyroelectric transducer applications. This review is

  3. Dynamic response of a piezoelectric flapping wing

    NASA Astrophysics Data System (ADS)

    Kumar, Alok; Khandwekar, Gaurang; Venkatesh, S.; Mahapatra, D. R.; Dutta, S.

    2015-03-01

    Piezo-composite membranes have advantages over motorized flapping where frequencies are high and certain coupling between bending and twisting is useful to generate lift and forward flight. We draw examples of fruit fly and bumble bee. Wings with Piezo ceramic PZT coating are realized. The passive mechanical response of the wing is characterized experimentally and validated using finite element simulation. Piezoelectric actuation with uniform electrode coating is characterized and optimal frequencies for flapping are identified. The experimental data are used in an empirical model and advanced ratio for a flapping insect like condition for various angular orientations is estimated.

  4. The Titan Graphics Supercomputer Architecture

    Microsoft Academic Search

    Tom Diede; Carl F. Hagenmaier; Glen S. Miranker; Jonathan J. Rubinstein; William S. Worley Jr.

    1988-01-01

    The design criteria for the Titan are outlined, and the hardware, architecture, and implementation developed to meet them are examined. The key architectural elements in Titan are described, and the reasoning behind their selection is presented. Titan's processor subsystem is explored, focusing on how it reduces the cost and complexity of graphics-specific hardware. The design constraints and implementation of the

  5. Dielectric measurements of selected ceramics at microwave frequencies

    NASA Technical Reports Server (NTRS)

    Dahiya, J. N.; Templeton, C. K.

    1994-01-01

    Dielectric measurements of strontium titanate and lead titanate zirconate ceramics are conducted at microwave frequencies using a cylindrical resonant cavity in the TE(sub 011) mode. The perturbations of the electric field are recorded in terms of the frequency shift and Q-changes of the cavity signal. Slater's perturbation equations are used to calculate e' and e" of the dielectric constant as a function of temperature and frequency.

  6. Methane ocean on Titan?

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    There was an impressive list of names on a recent scientific communication that argues for the existence on Titan of an ocean of liquid methane (CH4) perhaps several hundred meters deep. C. Sagan and S. Dermott with helpful comments by S. Oter, S. Ostro, S. Peale, C. Yoder, W. Thompson, S. Squyres, G. Pettengill, P. Gierasch, and B. Khare speculate that such a methanic ocean, with its Saturnian tides and its tholinian floor, should exist all over Titan's surface; it should unless, they conclude, there is the ‘distracting coincidence [that] … the position of the surface of Titan [is] … near the liquidus in the CH4phase diagram [and, consequently, there is] …almost no methane ocean at all’ (Nature, 300, 731, 1982).We know very little about Titan and its surface; the way of checking into Sagan and Dermott's ideas appears to rest on the interpretation of radar reflectivity data. Preliminary attempts to obtain radar data were made in 1979 with the 305-m Arecibo telescope, but only broad limits resulted. The next opportunity for a measurement at Arecibo comes in the 1990's. Of course, the ideal circumstance would be to send spacecraft equipped with a radar reflectometer for a Titan flyby.

  7. Titan Orbiter Aerorover Mission

    NASA Technical Reports Server (NTRS)

    Sittler Jr., E. C.; Acuna, M.; Burchell, M. J.; Coates, A.; Farrell, W.; Flasar, M.; Goldstein, B. E.; Gorevan, S.; Hartle, R. E.; Johnson, W. T. K.

    2001-01-01

    We propose a combined Titan orbiter and Titan Aerorover mission with an emphasis on both in situ and remote sensing measurements of Titan's surface, atmosphere, ionosphere, and magnetospheric interaction. The biological aspect of the Titan environment will be emphasized by the mission (i.e., search for organic materials which may include simple organics to 'amono' analogues of amino acids and possibly more complex, lightening detection and infrared, ultraviolet, and charged particle interactions with Titan's surface and atmosphere). An international mission is assumed to control costs. NASA will provide the orbiter, launch vehicle, DSN coverage and operations, while international partners will provide the Aerorover and up to 30% of the cost for the scientific instruments through collaborative efforts. To further reduce costs we propose a single PI for orbiter science instruments and a single PI for Aerorover science instruments. This approach will provide single command/data and power interface between spacecraft and orbiter instruments that will have redundant central DPU and power converter for their instruments. A similar approach could be used for the Aerorover. The mission profile will be constructed to minimize conflicts between Aerorover science, orbiter radar science, orbiter radio science, orbiter imaging science, and orbiter fields and particles (FP) science. Additional information is contained in the original extended abstract.

  8. High-sensitivity piezoelectric perovskites for magnetoelectric composites

    NASA Astrophysics Data System (ADS)

    Amorín, Harvey; Algueró, Miguel; Del Campo, Rubén; Vila, Eladio; Ramos, Pablo; Dollé, Mickael; Romaguera-Barcelay, Yonny; Pérez De La Cruz, Javier; Castro, Alicia

    2015-02-01

    A highly topical set of perovskite oxides are high-sensitivity piezoelectric ones, among which Pb(Zr,Ti)O3 at the morphotropic phase boundary (MPB) between ferroelectric rhombohedral and tetragonal polymorphic phases is reckoned a case study. Piezoelectric ceramics are used in a wide range of mature, electromechanical transduction technologies like piezoelectric sensors, actuators and ultrasound generation, to name only a few examples, and more recently for demonstrating novel applications like magnetoelectric composites. In this case, piezoelectric perovskites are combined with magnetostrictive materials to provide magnetoelectricity as a product property of the piezoelectricity and piezomagnetism of the component phases. Interfaces play a key issue, for they control the mechanical coupling between the piezoresponsive phases. We present here main results of our investigation on the suitability of the high sensitivity MPB piezoelectric perovskite BiScO3–PbTiO3 in combination with ferrimagnetic spinel oxides for magnetoelectric composites. Emphasis has been put on the processing at low temperature to control reactions and interdiffusion between the two oxides. The role of the grain size effects is extensively addressed.

  9. The tides of Titan.

    PubMed

    Iess, Luciano; Jacobson, Robert A; Ducci, Marco; Stevenson, David J; Lunine, Jonathan I; Armstrong, John W; Asmar, Sami W; Racioppa, Paolo; Rappaport, Nicole J; Tortora, Paolo

    2012-07-27

    We have detected in Cassini spacecraft data the signature of the periodic tidal stresses within Titan, driven by the eccentricity (e = 0.028) of its 16-day orbit around Saturn. Precise measurements of the acceleration of Cassini during six close flybys between 2006 and 2011 have revealed that Titan responds to the variable tidal field exerted by Saturn with periodic changes of its quadrupole gravity, at about 4% of the static value. Two independent determinations of the corresponding degree-2 Love number yield k(2) = 0.589 ± 0.150 and k(2) = 0.637 ± 0.224 (2?). Such a large response to the tidal field requires that Titan's interior be deformable over time scales of the orbital period, in a way that is consistent with a global ocean at depth. PMID:22745254

  10. Piezoelectric properties of (Pb/sub 1-x/Ba/sub x/)/sub 2/NaNb/sub 5/O/sub 15/ ceramic under pressure along the polarization direction

    SciTech Connect

    Lopatin, S.S.; Medvedev, B.S.; Biyatenko, Yu.N.; Basenko, N.I.

    1987-02-01

    The authors use x-ray diffraction to study polarization and depolarization under a pressure of 380 MPa in the title ceramic where the value of x falls between 0.1 and 0.6. They establish that the irreversible and reversible changes in the piezomodulus, due to pressure along the direction of polarization, are determined by the phase composition of the ceramic. The greatest irreversible changes in the modulus are observed in the morphotropic region where x lies between 0.33 and 0.43, due to 90/sup 0/ disorientation of the phase domains with polar direction (010), and also to mutual transitions between coexistent phases.

  11. Impact craters on Titan

    USGS Publications Warehouse

    Wood, Charles A.; Lorenz, Ralph; Kirk, Randy; Lopes, Rosaly; Mitchell, Karl; Stofan, Ellen; Cassini RADAR Team

    2010-01-01

    Five certain impact craters and 44 additional nearly certain and probable ones have been identified on the 22% of Titan's surface imaged by Cassini's high-resolution radar through December 2007. The certain craters have morphologies similar to impact craters on rocky planets, as well as two with radar bright, jagged rims. The less certain craters often appear to be eroded versions of the certain ones. Titan's craters are modified by a variety of processes including fluvial erosion, mass wasting, burial by dunes and submergence in seas, but there is no compelling evidence of isostatic adjustments as on other icy moons, nor draping by thick atmospheric deposits. The paucity of craters implies that Titan's surface is quite young, but the modeled age depends on which published crater production rate is assumed. Using the model of Artemieva and Lunine (2005) suggests that craters with diameters smaller than about 35 km are younger than 200 million years old, and larger craters are older. Craters are not distributed uniformly; Xanadu has a crater density 2-9 times greater than the rest of Titan, and the density on equatorial dune areas is much lower than average. There is a small excess of craters on the leading hemisphere, and craters are deficient in the north polar region compared to the rest of the world. The youthful age of Titan overall, and the various erosional states of its likely impact craters, demonstrate that dynamic processes have destroyed most of the early history of the moon, and that multiple processes continue to strongly modify its surface. The existence of 24 possible impact craters with diameters less than 20 km appears consistent with the Ivanov, Basilevsky and Neukum (1997) model of the effectiveness of Titan's atmosphere in destroying most but not all small projectiles.

  12. Titan's Winter Polar Vortex

    NASA Technical Reports Server (NTRS)

    Flasar, F.M.; Achterberg, R.K.; Schinder, P.J.

    2008-01-01

    Titan's atmosphere has provided an interesting study in contrasts and similarities with Earth's. While both have N$_2$ as the dominant constituent and comparable surface pressures $\\sim1$ bar, Titan's next most abundant molecule is CH$_4$, not O$_2$, and the dissociative breakup of CH$_4$ and N$_2$ by sunlight and electron impact leads to a suite of hydrocarbons and nitriles, and ultimately the photochemical smog that enshrouds the moon. In addition, with a 15.95-day period, Titan is a slow rotator compared to Earth. While the mean zonal terrestrial winds are geostrophic, Titan's are mostly cyclostrophic, whipping around the moon in as little as 1 day. Despite the different dynamical regime, Titan's winter stratosphere exhibits several characteristics that should be familiar to terrestrial meteorologists. The cold winter pole near the 1 -mbar level is circumscribed by strong winds (up to 190 m/s) that act as a barrier to mixing with airmasses at lower latitudes. There is evidence of enhancement of several organic species over the winter pole, indicating subsidence. The adiabatic heating associated with this subsidence gives rise to a warm anomaly at the 0.01-mbar level, raising the stratopause two scale heights above its location at equatorial latitudes. Condensate ices have been detected in Titan's lower stratosphere within the winter polar vortex from infrared spectra. Although not always unambiguously identified, their spatial distribution exhibits a sharp gradient, decreasing precipitously across the vortex away from the winter pole. The interesting question of whether there is important heterogeneous chemistry occurring within the polar vortex, analogous to that occurring in the terrestrial polar stratospheric clouds in the ozone holes, has not been addressed. The breakup of Titan's winter polar vortex has not yet been observed. On Earth, the polar vortex is nonlinearly disrupted by interaction with large-amplitude planetary waves. Large-scale waves have not been identified in Titan's atmosphere, so the decay of its polar vortex may be more gradual than on Earth. Observations from an extended Cassini mission into late northern spring should provide critical data indicating whether the vortex goes away with a bang or just fades away.

  13. Modeling and characterization of electrostrictive ceramics

    NASA Astrophysics Data System (ADS)

    Sherrit, Stewart; Catoiu, Georgeta; Stimpson, Russell B.; Mukherjee, Benoy K.

    1998-07-01

    We present a non-linear theory for electromechanical materials based on a Taylor's series expansion of the thermodynamic potentials to 3rd and higher order terms in field and stress, and we show that this general theory is applicable to both piezoelectric and ideal electrostrictive materials depending with an appropriate choice of material coefficients. The model allows for the non-zero piezoelectric behavior found in some nominally electrostrictive materials. The quasistatic non-linear equations used to describe low frequency electromechanical devices are shown to account for saturation in both strain and polarization as well as the stress dependence. The `reversible' electrostrictive ceramic PMN/PT/La (0.9/0.1/1%) operating above Tmax is used to illustrate the suitability of the model. Under a DC bias field, these materials behave as a piezoelectric ceramic material with C?) symmetry. The effective piezoelectric is found to be linear as a function of the DC bias field up to about 0.5MV/m. Above 0.5 MV/m, the piezoelectric and the electromechanical coupling constants begin to saturate due to higher 4th order electrostriction (S ~ kE4 with k negative), which is shown to be the result of the saturation in the dielectric response. A switchable, low field, linear component of the piezoelectric voltage coefficient, g, is found in the S vs D response. The g coefficient is found to change sign depending on the sign of the measurement field. These materials behave as a tunable piezoelectric with the piezoelectric coefficient being directly proportional to the electrostrictive coefficient and the DC bias field, up to saturation.

  14. A very promising piezoelectric property of Ta 2O 5 thin films. II: Birefringence and piezoelectricity

    NASA Astrophysics Data System (ADS)

    Audier, M.; Chenevier, B.; Roussel, H.; Vincent, L.; Peña, A.; Lintanf Salaün, A.

    2011-08-01

    Birefringent and piezoelectric properties of Ta 2O 5 ceramic thin films of monoclinic and trigonal structures were analyzed. The birefringence, observed by reflected polarized light microscopy, yields information on thin film microstructures, crystal shapes and sizes and on crystallographic orientations of grains of trigonal structure. Such an information was considered for investigating piezoelectric properties by laser Doppler vibrometry and by piezoresponse force microscopy. The vibration velocity was measured by applying an oscillating electric field between electrodes on both sides of a Ta 2O 5 film deposited on a Si substrate which was pasted on an isolating mica sheet. In this case, it is shown that the vibration velocity results were not only from a converse piezoelectric effect, proportional to the voltage, but also from the Coulomb force, proportional to the square of the voltage. A huge piezoelectric strain effect, up to 7.6%, is found in the case of Ta 2O 5 of trigonal structure. From an estimation of the electrical field through the Ta 2O 5 thin film, this strain likely corresponds to a very high longitudinal coefficient d33 of several thousand picometers. Results obtained by piezoresponse force microscopy show that trigonal grains exhibit a polarization at zero field, which is probably due to stress caused expansion in the transition monoclinic-trigonal, presented in a previous article (part I).

  15. Piezoelectric ribbons printed onto rubber for flexible energy conversion.

    PubMed

    Qi, Yi; Jafferis, Noah T; Lyons, Kenneth; Lee, Christine M; Ahmad, Habib; McAlpine, Michael C

    2010-02-10

    The development of a method for integrating highly efficient energy conversion materials onto stretchable, biocompatible rubbers could yield breakthroughs in implantable or wearable energy harvesting systems. Being electromechanically coupled, piezoelectric crystals represent a particularly interesting subset of smart materials that function as sensors/actuators, bioMEMS devices, and energy converters. Yet, the crystallization of these materials generally requires high temperatures for maximally efficient performance, rendering them incompatible with temperature-sensitive plastics and rubbers. Here, we overcome these limitations by presenting a scalable and parallel process for transferring crystalline piezoelectric nanothick ribbons of lead zirconate titanate from host substrates onto flexible rubbers over macroscopic areas. Fundamental characterization of the ribbons by piezo-force microscopy indicates that their electromechanical energy conversion metrics are among the highest reported on a flexible medium. The excellent performance of the piezo-ribbon assemblies coupled with stretchable, biocompatible rubber may enable a host of exciting avenues in fundamental research and novel applications. PMID:20102189

  16. Large displacement vertical translational actuator based on piezoelectric thin films

    PubMed Central

    Qiu, Zhen; Pulskamp, Jeffrey S; Lin, Xianke; Rhee, Choong-Ho; Wang, Thomas; Polcawich, Ronald G; Oldham, Kenn

    2014-01-01

    A novel vertical translational microactuator based on thin-film piezoelectric actuation is presented, using a set of four compound bend-up/bend-down unimorphs to produce translational motion of a moving platform or stage. The actuation material is a chemical-solution deposited lead–zirconate–titanate (PZT) thin film. Prototype designs have shown as much as 120 ?m of static displacement, with 80–90 ?m displacements being typical, using four 920 ?m long by 70 ?m legs. Analytical models are presented that accurately describe nonlinear behavior in both static and dynamic operation of prototype stages when the dependence of piezoelectric coefficients on voltage is known. Resonance of the system is observed at a frequency of 200 Hz. The large displacement and high bandwidth of the actuators at low-voltage and low-power levels should make them useful to a variety of optical applications, including endoscopic microscopy. PMID:25506130

  17. PZT Thin Film Piezoelectric Traveling Wave Motor

    NASA Technical Reports Server (NTRS)

    Shen, Dexin; Zhang, Baoan; Yang, Genqing; Jiao, Jiwei; Lu, Jianguo; Wang, Weiyuan

    1995-01-01

    With the development of micro-electro-mechanical systems (MEMS), its various applications are attracting more and more attention. Among MEMS, micro motors, electrostatic and electromagnetic, are the typical and important ones. As an alternative approach, the piezoelectric traveling wave micro motor, based on thin film material and integrated circuit technologies, circumvents many of the drawbacks of the above mentioned two types of motors and displays distinct advantages. In this paper we report on a lead-zirconate-titanate (PZT) piezoelectric thin film traveling wave motor. The PZT film with a thickness of 150 micrometers and a diameter of 8 mm was first deposited onto a metal substrate as the stator material. Then, eight sections were patterned to form the stator electrodes. The rotor had an 8 kHz frequency power supply. The rotation speed of the motor is 100 rpm. The relationship of the friction between the stator and the rotor and the structure of the rotor on rotation were also studied.

  18. Fatigue life characterization for piezoelectric macrofiber composites

    NASA Astrophysics Data System (ADS)

    Henslee, Isaac A.; Miller, David A.; Tempero, Tyler

    2012-10-01

    In an effort to aid the investigation into lightweight and reliable materials for actuator design, a study was developed to characterize the temperature-dependent lifetime performance of a piezoelectric macrofiber composite (MFC). MFCs are thin rectangular patches of polyimide film, epoxy and a single layer of rectangular lead zirconium titanate (PZT) fibers. In this study, the useful life of the MFC is characterized to determine the effect of temperature on the performance of the composite as it is fatigued by cyclic piezoelectric excitation. The test specimen consists of the MFC laminated to a cantilevered stainless steel beam. Beam strain and tip displacement measurements are used as a basis for determining the performance of the MFC as it is cyclically actuated under various operating temperatures. The temperature of the beam laminate is held constant and then cycled to failure, or 250 million cycles, in order to determine the useful life of the MFC over a temperature range from - 15 to 145?°C. The results of the experiments show a strong temperature dependence of the operational life for the MFC. Damage inside the composite was identified through in situ visual inspection and during post-test microstructural observation; however, no degradation in operational performance was identified as it was cyclically actuated up to the point of failure, regardless of temperature or actuation cycle number.

  19. Energy harvesting MEMS device based on thin film piezoelectric cantilevers

    Microsoft Academic Search

    W. J. Choi; Y. Jeon; J.-H. Jeong; R. Sood; S. G. Kim

    2006-01-01

    A thin film lead zirconate titanate Pb(Zr,Ti)O3 (PZT), energy harvesting MEMS device is developed to enable self-supportive sensors for in-service integrity monitoring of\\u000a large social and environmental infrastructures at remote locations. It is designed to resonate at specific frequencies of\\u000a an external vibrational energy source, thereby creating electrical energy via the piezoelectric effect. Our cantilever device\\u000a has a PZT\\/SiNx bimorph

  20. Rayleigh analysis of dielectric properties in textured K0.5Na0.5NbO3 ceramics

    NASA Astrophysics Data System (ADS)

    Haugen, Astri Bjørnetun; Morozov, Maxim I.; Jones, Jacob L.; Einarsrud, Mari-Ann

    2014-12-01

    Grain texturing is a known method of exploiting the intrinsic dielectric and piezoelectric anisotropy in ferroelectric ceramics. However, the role of crystallographic texture on anisotropic extrinsic contributions including domain wall motion is not yet understood. Here, we investigate the dielectric and piezoelectric properties and small signal dielectric nonlinearities in K0.5Na0.5NbO3 ceramics in different directions of textured specimens and compare to ceramics without crystallographic texture. We demonstrate that directions in which pseudo-cubic <100> poles have greatest orientation density exhibit both an enhanced longitudinal piezoelectric response and lower dielectric nonlinearity.

  1. Piezoelectric cantilever acoustic transducer

    Microsoft Academic Search

    Seung S. Lee; Richard M. White

    1998-01-01

    We present a piezoelectric acoustic transducer fabricated on a bulk-micromachined cantilever diaphragm. Use of the cantilever as a supporting diaphragm produces a highly sensitive microphone. In addition, when the device is driven electrically as an output transducer, a microspeaker, the relatively large deflections produce significant acoustic output. A voltage-to-frequency converter has also been demonstrated with piezoelectric cantilever transducers. The 0960-1317\\/8\\/3\\/009\\/img5

  2. Piezoelectric cantilever acoustic transducer

    Microsoft Academic Search

    Seung S Leey; Richard M White

    1998-01-01

    We present a piezoelectric acoustic transducer fabricated on a bulk-micromachined cantilever diaphragm. Use of the cantilever as a supporting diaphragm produces a highly sensitive microphone. In addition, when the device is driven electrically as an output transducer, a microspeaker, the relatively large deflections produce significant acoustic output. A voltage-to-frequency converter has also been demonstrated with piezoelectric cantilever transducers. The 2

  3. Laminated piezoelectric transformer

    NASA Technical Reports Server (NTRS)

    Vazquez Carazo, Alfredo (Inventor)

    2006-01-01

    A laminated piezoelectric transformer is provided using the longitudinal vibration modes for step-up voltage conversion applications. The input portions are polarized to deform in a longitudinal plane and are bonded to an output portion. The deformation of the input portions is mechanically coupled to the output portion, which deforms in the same longitudinal direction relative to the input portion. The output portion is polarized in the thickness direction relative its electrodes, and piezoelectrically generates a stepped-up output voltage.

  4. Photothermoacoustic oscillations in a solid-piezoelectric layered structure

    NASA Astrophysics Data System (ADS)

    Kozachenko, V. V.; Kucherov, I. Ya.

    2004-03-01

    Photothermoacoustic oscillations in a thin plane-layered structure consisting of an isotropic solid and a piezoelectric crystal of class 6 mm (or piezoelectric ceramics) are studied theoretically and experimentally. Expressions for the potential difference across an arbitrary layer of the piezoelectric transducer are derived. For the case of a two-layer transducer, the amplitude-frequency and phase-frequency dependences of the signal are analyzed. It is shown that, from these experimental dependences, one can determine certain elastic and thermal parameters of a solid. An experiment is performed with samples of Cu, Zn, and TsTS-19 piezoceramics in the frequency range within 9 1000 Hz. The experimental data are used to determine the values of the reduced Young’s modulus and the thermal diffusivity of the materials under study.

  5. Electrical Properties and Power Considerations of a Piezoelectric Actuator

    NASA Technical Reports Server (NTRS)

    Jordan, T.; Ounaies, Z.; Tripp, J.; Tcheng, P.

    1999-01-01

    This paper assesses the electrical characteristics of piezoelectric wafers for use in aeronautical applications such as active noise control in aircraft. Determination of capacitive behavior and power consumption is necessary to optimize the system configuration and to design efficient driving electronics. Empirical relations are developed from experimental data to predict the capacitance and loss tangent of a PZT5A ceramic as nonlinear functions of both applied peak voltage and driving frequency. Power consumed by the PZT is the rate of energy required to excite the piezoelectric system along with power dissipated due to dielectric loss and mechanical and structural damping. Overall power consumption is thus quantified as a function of peak applied voltage and driving frequency. It was demonstrated that by incorporating the variation of capacitance and power loss with voltage and frequency, satisfactory estimates of power requirements can be obtained. These relations allow general guidelines in selection and application of piezoelectric actuators and driving electronics for active control applications.

  6. Domain-size dependence of piezoelectric properties of ferroelectrics

    NASA Astrophysics Data System (ADS)

    Ahluwalia, Rajeev; Lookman, Turab; Saxena, Avadh; Cao, Wenwu

    2005-07-01

    The domain-size dependence of the piezoelectric properties of ferroelectrics is investigated using a continuum Ginzburg-Landau model that incorporates long-range elastic and electrostatic interactions. Microstructures with the desired domain sizes are created by quenching from the paraelectric phase by biasing the initial conditions. Three different two-dimensional microstructures with different sizes of the 90° domains are simulated. An electric field is applied along the polar as well as nonpolar directions and the piezoelectric response is simulated as a function of domain size for both cases. The simulations show that the piezoelectric coefficients are enhanced by reducing the domain size, consistent with recent experimental results of Wada and Tsurumi [Br. Ceram. Trans. 103, 93 (2004)] on domain-engineered BaTiO3 single crystals.

  7. Domain Size Dependence of Piezoelectric Properties of Ferroelectrics

    NASA Astrophysics Data System (ADS)

    Saxena, Avadh; Cao, Wenwu

    2005-03-01

    The domain size dependence of piezoelectric properties of ferroelectrics is investigated using a continuum Ginzburg-Landau model that incorporates the long-range elastic and electrostatic interactions. Microstructures with desired domain sizes are created by quenching from the paraelectric phase by biasing the initial conditions. Three different two-dimensional microstructures with different sizes of the 90^o domains are simulated. An electric field is applied along the polar as well as non-polar directions and the piezoelectric response is simulated as a function of domain size for both cases. The simulations show that the piezoelectric coefficients are enhanced by reducing the domain size, consistent with recent experimental results of Wada and Tsurumi (Brit. Ceram. Trans. 103, 93, 2004) on domain engineered BaTiO3 single crystals.

  8. Titan after Cassini Huygens

    Microsoft Academic Search

    P. M. Beauchamp; J. Lunine; J. Lebreton; A. Coustenis; D. Matson; K. Reh; C. Erd

    2008-01-01

    In 2005, the Huygens Probe gave us a snapshot of a world tantalizingly like our own, yet frozen in its evolution on the threshold of life. The descent under parachute, like that of Huygens in 2005, is happening again, but this time in the Saturn-cast twilight of winter in Titan's northern reaches. With a pop, the parachute is released, and

  9. The lakes of Titan

    Microsoft Academic Search

    E. R. Stofan; C. Elachi; J. I. Lunine; R. D. Lorenz; B. Stiles; K. L. Mitchell; S. Ostro; L. Soderblom; C. Wood; H. Zebker; S. Wall; M. Janssen; R. Kirk; R. Lopes; F. Paganelli; J. Radebaugh; L. Wye; Y. Anderson; M. Allison; R. Boehmer; P. Callahan; P. Encrenaz; E. Flamini; G. Francescetti; Y. Gim; S. Hensley; W. T. K. Johnson; K. Kelleher; D. Muhleman; P. Paillou; G. Picardi; F. Posa; L. Roth; R. Seu; S. Shaffer; S. Vetrella

    2007-01-01

    The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for

  10. Semiconducting barium titanate

    Microsoft Academic Search

    W. Heywang

    1971-01-01

    Barium titanate, which is well known as a basic ferroelectric material, is also of interest when doped because of the interaction between semiconductivity and ferroelectricity. The resistance of blocking layers at surfaces and grain-boundaries is governed mainly by the ferroelectric properties, so that a resistance jump of four decades is observed on heating above the Curie temperature. A survey of

  11. Methane rain on Titan

    Microsoft Academic Search

    O. B. Toon; C. P. Mckay; R. Courtin; T. P. Ackerman

    1988-01-01

    The atmosphere of Titan is characterized by means of model computations based on Voyager IRIS IR spectra and published data from laboratory determinations of absorption coefficients and cloud refractive indices. The results are presented in tables and graphs, and it is pointed out that the presence of Ar is not required in the model. Particular attention is given to the

  12. Clash of the Titans

    NSDL National Science Digital Library

    Karthigeyan Subramaniam

    2010-01-01

    WebQuests and the 5E learning cycle are titans of the science classroom. These popular inquiry-based strategies are most often used as separate entities, but the author has discovered that using a combined WebQuest and 5E learning cycle format taps into t

  13. Fundamental study of hydrothermally synthesized lead zirconate titanate polycrystals deposited on a Ti substrate during nucleation

    NASA Astrophysics Data System (ADS)

    Abe, Toshinobu; Ozeki, Seiya; Kuribayashi Kurosawa, Minoru; Takeuchi, Shinichi

    2015-07-01

    We previously fabricated a piezoelectric transducer from a lead zirconate titanate (PZT) polycrystalline film deposited on a Ti substrate by a hydrothermal synthesis method. However, the hydrothermal synthesis required a long deposition time to achieve the necessary film thickness. In this study, we confirmed that the thickness of the PZT polycrystalline film increased when the solution was stirred at 245 rpm during synthesis, and that the optimum deposition time was 5 h.

  14. Local origin of macroscopic properties and patterning in Lead zirconate titanate films

    Microsoft Academic Search

    Patamas Bintachitt

    2009-01-01

    This thesis describes the preparation of high quality lead zirconate titanate (PZT) films, the nonlinearity in their dielectric and piezoelectric responses, as well as their patterning by reactive ion etching. One goal of the research was to obtain {001} oriented PZT films on Pt-coated Si substrates. In this work, PbTiO3 buffer layers were chosen due to good lattice matching with

  15. 3D Piezoelectric Structures Made by Ink-Jet Printing

    Microsoft Academic Search

    Gautier Senlis; Matthieu Dubarry; Martine Lejeune; Thierry Chartier

    2002-01-01

    The purpose of this paper is to report the potential interest to develop piezoelectric structures by taking advantage both of the adaptive electromechanical behavior of 0.9PbMg 1\\/3 Nb 2\\/3 O 3 (PMN)-0.1PbTiO 3 (PT) ceramics and of the characteristics of rapid prototyping methods. In fact, as the piezo-activity of 0.9PMN-0.1PT ceramics is adjustable via the amplitude of the electric field;

  16. Titan atmospheric composition

    NASA Astrophysics Data System (ADS)

    Coustenis, A.; Cirs Investigation Team

    Titan s atmospheric composition has become known to us from the Voyager missions and more recently through the explorations by the ISO and Cassini instruments ISO has provided the detection of the water vapor in Titan s atmosphere Coustenis et al 1998 and given a precise measure of the chemical composition as a disk-average Coustenis et al 2003 More recently data recorded by the Composite Infrared Spectrometer CIRS aboard the Cassini spacecraft became available during the recent Titan flybys Flasar et al 2005 Teanby et al 2006 The spectra characterize various regions on Titan from 75 r S to 75 r N with a variety of emission angles We study the emission observed in the mid-infrared CIRS detector arrays covering roughly the 600-1500 cm -1 spectral range with apodized resolutions of 2 54 or 0 53 cm -1 The composite spectrum shows several molecular signatures hydrocarbons nitriles and CO 2 A firm detection of benzene C 6 H 6 is also provided by CIRS at 674 cm -1 We have used temperature profiles retrieved from the inversion of the emission observed in the methane nu 4 band at 1304 cm -1 and a line-by-line radiative transfer code to infer the abundances of the trace constituents and some of their isotopes in Titan s stratosphere Coustenis et al 2006 No longitudinal variations were found for the gases Information is retrieved on the meridional variations of the trace constituents and tied to predictions by dynamical-photochemical models Molecules showing a significant enhancement at

  17. Synthesis and electrical analysis of nano-crystalline barium titanate nanocomposites for use in high-energy density applications.

    SciTech Connect

    DiAntonio, Christopher Brian; Yang, Pin; Chavez, Tom P.; Huber, Dale L.; Winter, Michael R.; Monson, Todd C.; Roesler, Alexander William

    2010-10-01

    Ceramic based nanocomposites have recently demonstrated the ability to provide enhanced permittivity, increased dielectric breakdown strength, and reduced electromechanical strain making them potential materials systems for high energy density applications. A systematic characterization and optimization of barium titanate and PLZT based nanoparticle composites employing a glass or polymer matrix to yield a high energy density component will be presented. This work will present the systematic characterization and optimization of barium titanate and lead lanthanum zirconate titanate nanoparticle based ceramics. The nanoparticles have been synthesized using solution and pH-based synthesis processing routes and employed to fabricate polycrystalline ceramic and nanocomposite based components. The dielectric/ferroelectric properties of these various components have been gauged by impedance analysis and electromechanical response and will be discussed.

  18. Titanic Weather Forecasting

    NASA Astrophysics Data System (ADS)

    2004-04-01

    New Detailed VLT Images of Saturn's Largest Moon Optimizing space missions Titan, the largest moon of Saturn was discovered by Dutch astronomer Christian Huygens in 1655 and certainly deserves its name. With a diameter of no less than 5,150 km, it is larger than Mercury and twice as large as Pluto. It is unique in having a hazy atmosphere of nitrogen, methane and oily hydrocarbons. Although it was explored in some detail by the NASA Voyager missions, many aspects of the atmosphere and surface still remain unknown. Thus, the existence of seasonal or diurnal phenomena, the presence of clouds, the surface composition and topography are still under debate. There have even been speculations that some kind of primitive life (now possibly extinct) may be found on Titan. Titan is the main target of the NASA/ESA Cassini/Huygens mission, launched in 1997 and scheduled to arrive at Saturn on July 1, 2004. The ESA Huygens probe is designed to enter the atmosphere of Titan, and to descend by parachute to the surface. Ground-based observations are essential to optimize the return of this space mission, because they will complement the information gained from space and add confidence to the interpretation of the data. Hence, the advent of the adaptive optics system NAOS-CONICA (NACO) [1] in combination with ESO's Very Large Telescope (VLT) at the Paranal Observatory in Chile now offers a unique opportunity to study the resolved disc of Titan with high sensitivity and increased spatial resolution. Adaptive Optics (AO) systems work by means of a computer-controlled deformable mirror that counteracts the image distortion induced by atmospheric turbulence. It is based on real-time optical corrections computed from image data obtained by a special camera at very high speed, many hundreds of times each second (see e.g. ESO Press Release 25/01 , ESO PR Photos 04a-c/02, ESO PR Photos 19a-c/02, ESO PR Photos 21a-c/02, ESO Press Release 17/02, and ESO Press Release 26/03 for earlier NACO images, and ESO Press Release 11/03 for MACAO-VLTI results.) The southern smile ESO PR Photo 08a/04 ESO PR Photo 08a/04 Images of Titan on November 20, 25 and 26, 2002 Through Five Filters (VLT YEPUN + NACO) [Preview - JPEG: 522 x 400 pix - 40k] [Normal - JPEG: 1043 x 800 pix - 340k] [Hires - JPEG: 2875 x 2205 pix - 1.2M] Caption: ESO PR Photo 08a/04 shows Titan (apparent visual magnitude 8.05, apparent diameter 0.87 arcsec) as observed with the NAOS/CONICA instrument at VLT Yepun (Paranal Observatory, Chile) on November 20, 25 and 26, 2003, between 6.00 UT and 9.00 UT. The median seeing values were 1.1 arcsec and 1.5 arcsec respectively for the 20th and 25th. Deconvoluted ("sharpened") images of Titan are shown through 5 different narrow-band filters - they allow to probe in some detail structures at different altitudes and on the surface. Depending on the filter, the integration time varies from 10 to 100 seconds. While Titan shows its leading hemisphere (i.e. the one observed when Titan moves towards us) on Nov. 20, the trailing side (i.e the one we see when Titan moves away from us in its course around Saturn) - which displays less bright surface features - is observed on the last two dates. ESO PR Photo 08b/04 ESO PR Photo 08b/04 Titan Observed Through Nine Different Filters on November 26, 2002 [Preview - JPEG: 480 x 400 pix - 36k] [Normal - JPEG: 960 x 800 pix - 284k] Caption: ESO PR Photo 08b/04: Images of Titan taken on November 26, 2002 through nine different filters to probe different altitudes, ranging from the stratosphere to the surface. On this night, a stable "seeing" (image quality before adaptive optics correction) of 0.9 arcsec allowed the astronomers to attain the diffraction limit of the telescope (0.032 arcsec resolution). Due to these good observing conditions, Titan's trailing hemisphere was observed with contrasts of about 40%, allowing the detection of several bright features on this surface region, once thought to be quite dark and featureless. ESO PR Photo 08c/04 ESO PR Photo 08c/04 Titan Surface Projections [Previ

  19. Titan Student Centers Introduction and Overview ................................................. Section

    E-print Network

    de Lijser, Peter

    #12;Titan Student Centers Introduction and Overview ................................................. Section Page One One Titan Student Centers 2014-15 Fiscal Year Budget Charts and Tables .............................................................. Section Page Four Two Titan Student Centers 2014-15 Fiscal Year Budget Note Package

  20. Hydrocarbon Trapping in Titan Surface Materials

    NASA Astrophysics Data System (ADS)

    Cable, M. L.; Vu, T.; Choukroun, M.; Markus, C.; Hodyss, R.; Beauchamp, P.

    2014-02-01

    Benzene is found on Titan and is probably one of the most abundant evaporites to form around Titan lakes. We discovered trapping of ethane in crystalline benzene at 90 K, suggesting evaporite basins could act as hydrocarbon reservoirs on Titan.

  1. Development of MEMS piezoelectric energy harvesters

    NASA Astrophysics Data System (ADS)

    Park, Jung-Hyun

    The research of powering devices in a microwatt range has been activated and developed by the emergence of low-power Very Large Scale Integration (VLSI) technology in the past few years. The powering devices require a size that is compatible with the application, sufficient power, and extended lifetime using permanent and ubiquitous energy sources. The piezoelectric energy harvester using vibration sources is attractive due to its high conversion efficiency, simple design for miniaturizing, and lack of external voltage source. While bulk piezoelectric energy harvesters produce enough power for a few tens of mW, the insufficient power is still a major issue during miniaturizing into micro size. The piezoelectric energy harvester was fabricated by micro-electro-mechanical systems (MEMS) and developed to enhance its output power. It was designed to be resonated at the frequency range of ambient vibration source (50˜300 Hz) and convert the mechanical stress to electricity by piezoelectric thin film. The cantilever structure was chosen in this study due to its large strain, and a big proof mass at the end of tip was integrated for the same reason. This study focuses on three specific issues related to the robust fabrication process, including the integration of piezoelectric thin film, structure design for high power density, and the reliability of device. The Lead Zirconate Titanate (PZT) thin films were prepared by a sol-gel process and were used to fabricate energy harvesters by an optimized MEMS process. The properties of PZT thin film were studied considering the substrate effect, heat treatment, and thickness effects. The fabricated energy harvester produced 769 mVpk-pk, and 6.72 muW with the optimal resistive load of 11 kO at 127 Hz of resonant frequency. The device had dimensions of about 4 mm(L) x 2 mm(w) x 0.021 mm(H), and the Si proof mass had dimensions of 3 mm(L) x 2 mm(W) x 0.5 mm(H). Beyond this result, the technical platform for the robust fabrication process was established on a Deep Reactive Ion Etcher (DRIE). The plasma etching using DRIE was optimized to prevent damage of the PZT film and to obtain uniform and precise dimension control. The trapezoidal shape of the cantilever was demonstrated to enhance the power density by stress distribution on the PZT film. The geometry change in cantilever shape distributed the strain on piezoelectric film and improved the output power ˜40% higher than that of the rectangular shape due to nonlinear piezoelectric properties. The multi-beam arrays were designed to obtain a multiplied electric power effect as if as number of cantilevers was used. The multibeam arrayed design requires the uniform machining to match the unified resonant frequency of each cantilever structure. Based on the optimized fabrication process, the cantilever array that consists of four cantilevers generated 18.39 muA and 1.352 muW with 4 kO of optimized resistive load in parallel connection under 1 G of acceleration force. The result was exactly four times higher power and current than that of individual cantilever. Finally, reliability tests were performed for the piezoelectric MEMS energy harvester considering the number of cyclic loads and temperature, and the degradation of PZT during fabrication was also investigated.

  2. Energy Harvesting Using a Piezoelectric ``Cymbal'' Transducer in Dynamic Environment

    Microsoft Academic Search

    Hyeoung Woo Kim; Amit Batra; Shashank Priya; Kenji Uchino; Douglas Markley; Robert E. Newnham; Heath F. Hofmann

    2004-01-01

    In this study, we investigated the capability of harvesting the electrical energy from mechanical vibrations in a dynamic environment through a ``cymbal'' piezoelectric transducer. Targeted mechanical vibrations lie in the range of 50-150 Hz with force amplitude in the order of 1 kN (automobile engine vibration level). It was found that under such severe stress conditions the metal-ceramic composite transducer

  3. Time-Resolved, Electric-Field-Induced Domain Switching and Strain in Ferroelectric Ceramics and Crystals

    NASA Astrophysics Data System (ADS)

    Jones, Jacob L.; Nino, Juan C.; Pramanick, Abhijit; Daniels, John E.

    Ferroelectric materials are used in a variety of applications including diagnostic and therapeutic ultrasound, sonar, vibration and displacement sensors, and non-volatile random access memory. The electromechanical response in ferroelectric materials is comprised of both intrinsic (piezoelectric lattice strain) and extrinsic (e.g., domain wall motion) components that are expressed as characteristic changes in the diffraction pattern. By applying slow, step-wise changes in the electric field, prior quasi-dynamic diffraction measurements have demonstrated both lattice strains and non-180 ? domain switching at fields exceeding the macroscopically defined coercive field. However, the loading conditions which most replicate real device operation involve dynamic actuation with sub-coercive, cyclic electric fields. At these operating conditions, extrinsic irreversibilities lead to hysteresis, frequency dispersion and nonlinearity of macroscopic properties. Observation of strain and domain switching at these cyclic loading conditions is an area in which we have reported recent advances using stroboscopic techniques. This chapter highlights the electric-field-induced lattice strain and kinetics of domain switching in a number of materials including technologically-relevant lead zirconate titanate (PZT) ceramics and relaxor single crystals. An outlook on the continuing use of time-resolved diffraction techniques in the characterization of ferroelectric materials is also discussed.

  4. Titan Mare Explorer (TiME): A Discovery Mission to Titan’s Hydrocarbon Lakes

    NASA Astrophysics Data System (ADS)

    Lorenz, R. D.; Stofan, E. R.; Lunine, J. I.; Kirk, R. L.; Mahaffy, P. R.; Bierhaus, B.; Aharonson, O.; Clark, B. C.; Kantsiper, B.; Ravine, M. A.; Waite, J. H.; Harri, A.; Griffith, C. A.; Trainer, M. G.

    2009-12-01

    The discovery of lakes in Titan’s high latitudes confirmed the expectation that liquid hydrocarbons exist on the surface of the haze-shrouded moon. The lakes fill through drainage of subsurface runoff and/or intersection with the subsurface alkanofer, providing the first evidence for an active condensable-liquid hydrological cycle on another planetary body. The unique nature of Titan’s methane cycle, along with the prebiotic chemistry and implications for habitability of Titan’s lakes, make the lakes of the highest scientific priority for in situ investigation. The Titan Mare Explorer mission is an ASRG (Advanced Stirling Radioisotope Generator)-powered mission to a lake on Titan. The mission would be the first exploration of a planetary sea beyond Earth, would demonstrate the ASRG both in deep space and a non-terrestrial atmosphere environment, and pioneer low-cost outer planet missions. The scientific objectives of the mission are to: determine the chemistry of a Titan lake to constrain Titan’s methane cycle; determine the depth of a Titan lake; characterize physical properties of liquids; determine how the local meteorology over the lakes ties to the global cycling of methane; and analyze the morphology of lake surfaces, and if possible, shorelines, in order to constrain the kinetics of liquids and better understand the origin and evolution of Titan lakes. The focused scientific goals, combined with the new ASRG technology and the unique mission design, allows for a new class of mission at much lower cost than previous outer planet exploration has required.

  5. Properties of Semiconductive Barium Titanates

    Microsoft Academic Search

    Osamu Saburi

    1959-01-01

    The resistivity of barium titanate which is usually of the order of 109˜1012 ohm-cm, may be remarkably reduced with suitable control in valency. The valency-controlled barium titanate, whose resistivity is of the order of 10˜104 ohm-cm at room temperature, shows anomalous positive character in the temperature dependency of the resistivity. For example, the resistivity of barium titanate containing 0.1 mol.

  6. Fully reversed electromechanical fatigue behavior of composite laminate with embedded piezoelectric actuator\\/sensor

    Microsoft Academic Search

    M. Yocum; H. Abramovich; A. Grunwald; S. Mall

    2003-01-01

    The functionality of a commercially available piezoelectric (lead zirconate-titanate (PZT)) actuator\\/sensor embedded in a quasi-isotropic graphite\\/epoxy composite while undergoing a combined electromechanical (E\\/M) fatigue under the fully reversed, tension-compression fatigue condition was investigated. The applied maximum stress levels ranged from 25 MPa (500 µvarepsilon) to 87.5 MPa (1750 µvarepsilon), which were in the range of 0.5-1.75 times its design limit

  7. Polarization switching and high piezoelectric response in Sn-modified BaTiO3

    NASA Astrophysics Data System (ADS)

    Kalyani, Ajay Kumar; Krishnan, Hari; Sen, Arijit; Senyshyn, Anatoliy; Ranjan, Rajeev

    2015-01-01

    BaTi O3 is shown to exhibit anomalous piezoelectric response, comparable to that of lead-zirconate titanate, by dilute Sn modification (1-4 mol%). Using a newly discovered powder poling technique it is shown that the mechanism associated with this anomalous strain response involves electric-field-induced switching of polarization vector from [001] towards [101] pseudocubic direction. This switchability is significantly enhanced by tuning the tetragonal-orthorhombic first-order criticality near to room temperature.

  8. Piezoelectric thin films formed by MOD on cantilever beams for micro sensors and actuators

    Microsoft Academic Search

    T. Cui; D. Markus; S. Zurn; D. L. Polla

    2004-01-01

    Novel piezoelectric cantilever beams for micro sensors and actuators based on PZT thin films have been batch fabricated by surface micromachining. Lead zirconate titanate (PZT) thin film is formed by metalorganic deposition (MOD) on Pt\\/Ti\\/SiO 2\\/Si (1 0 0) substrates and Pt\\/Ti\\/LTO\\/Si 3N 4 cantilever beams and then annealed at 700 °C in air. The PZT thin film is 0.5

  9. Rayleigh behaviour and the threshold field in ferroelectric ceramics

    Microsoft Academic Search

    David A Hall

    1999-01-01

    The threshold field, Et, values for various barium titanate and PZT-based ceramics have been determined by examination of the ?r -E0 and ?r -E0 relationships. The results obtained for both ‘soft’ and ’hard’ PZT ceramics gave a good fit to the Rayleigh Law over a wide range of field amplitude for E0Et. The linear increases in ?r and ?r as

  10. Observing Titan with amateur equipment

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph D.; Hergenrother, Carl; White, Brooke; West, J. Doug; Fujii, Mitsugu; Hatton, Jason

    We survey the observations of Titan that can be made using equipment available to amateur astronomers. Off-the-shelf hardware includes spectrometers and photometers that can detect Titan's infrared light curve and potentially its clouds. CCD spectra and photometry (both photoelectric and CCD), even with small (20 cm) telescopes, are useful for monitoring seasonal changes in Titan's haze. Recent remarkable advances in automatic stacking of thousands of short-exposure images obtained with webcams may even permit Titan's disk to be resolved. We additionally report some observations made with amateur equipment mounted on the 1.64 m Gerard P. Kuiper telescope on Mt. Bigelow.

  11. An investigation of aluminum titanate-spinel composites behavior in radiation

    NASA Astrophysics Data System (ADS)

    Cevikbas, G.; Tugrul, A. B.; Onen, U.; Boyraz, T.; Buyuk, B.

    2015-03-01

    In the present work, the radiation attenuation properties of Aluminum titanate (Al2TiO5)-Spinel (MgAl2O4) ceramics composites were investigated. Al2TiO5-MgAl2O4 ceramics composites which have different Al2TiO5 percentages (0%, 5% and 10%) were produced and performed against gamma sources. Cs-137 and Co-60 were used as gamma radiation sources. Transmission technique was used in the experiments. The linear and mass attenuation coefficients of the samples were carried out for gamma radiation sources. The experimental results were compared with the theoretical mass attenuation coefficients which were calculated by using XCOM computer code. Increasing Al2TiO5 percentage in the Aluminum titanate/ Spinel ceramics composites causes the higher linear and mass attenuation coefficients of the composites against Cs-137 and Co-60 gamma radioisotopes. Therefore Also theoretical mass attenuation coefficients are compatible with the experimental results. In conclusion, increasing the Aluminum titanate ratio in the Al2TiO5-MgAl2O4 ceramics composites increases the gamma shielding property of the Al2TiO5-MgAl2O4 ceramics for nuclear shielding applications.

  12. Poly(gamma-benzyl alpha, L glutamic acid)-based piezoelectric films & microfibers

    NASA Astrophysics Data System (ADS)

    Farrar, Dawnielle

    Piezoelectric materials in use today are often made of ceramic crystals. Although most ceramics offer high piezoelectricity, they are brittle and require expensive processing conditions. For applications where flexibility is required in addition to high piezoelectric activity, polymers are a very attractive alternative. An ideal piezoelectric material is the one where the piezoelectricity and mechanical properties can be altered individually so that the mechanical stiffness of the material can be varied for particular applications or tuned to match that of the surroundings (e.g. air or water) for increased transduction sensitivity. This is typically achieved by production of composite materials containing piezoelectric and matrix components. Here, we present new composite films and microfibers based on the biopolymer, poly(gamma-benzyl alpha,L-glutamate) (PBLG) and discuss their fabrication and piezoelectric properties. Fabrication of PBLG films and fibers was made possible by PBLG's extreme solubility in organic solvents. By simultaneous poling and curing of PBLG/methylmethacrylate (MMA) mixture solutions via corona charging, we fabricated a flexible composite film [80% PBLG and 20% Poly(methylmethacrylate) (PMMA)] with approximately 20% of the PBLG molecules oriented normal to the film surface. This PBLG film exhibited high piezoelectricity (d33 = 20 pC/N), and its Young's modulus was 1 GPa. However, significant amount of MMA evaporated during the corona charging process that precluded the fabrication of films with pre-determined PBLG-PMMA composition. We also fabricated thick composite disk (thickness: 3 cm) by breakdown charging and thermal polymerization of PBLG/PMMA mixture solution, a process that does not allow MMA evaporation. The composite disk exhibited low piezoelectricity (d33 ˜ 3 pC/N) due to low PBLG content (< 30%); however, its mechanical characteristics were similar to those of PMMA, indicating that the piezoelectricity and mechanical strength are independently related to the two polymer components of the composite disk. By electrospinning PBLG/dichloromethane (DCM) solutions under potentials of -(12˜15) kV, we produced piezoelectric microfibers (diameter: 100 nm) with nearly all of the PBLG dipoles oriented along the fiber axis, evidenced by x-ray diffraction. The PBLG fibers showed high piezoelectricity (d 33 = 32 pC/N), and an elastic modulus of 570 MPa. Both the piezoelectric film and fiber systems can be fabricated directly from solution in a mould or on a substrate. Due to the versatility in the fabrication process and the high piezoelectricity, these materials show great promise as transducer materials for loud speakers, microphones, and/or energy harvesting devices.

  13. Organic chemistry on Titan

    NASA Technical Reports Server (NTRS)

    Chang, S.; Scattergood, T.; Aronowitz, S.; Flores, J.

    1979-01-01

    Features taken from various models of Titan's atmosphere are combined in a working composite model that provides environmental constraints within which different pathways for organic chemical synthesis are determined. Experimental results and theoretical modeling suggest that the organic chemistry of the satellite is dominated by two processes: photochemistry and energetic particle bombardment. Photochemical reactions of CH4 in the upper atmosphere can account for the presence of C2 hydrocarbons. Reactions initiated at various levels of the atmosphere by cosmic rays, Saturn 'wind', and solar wind particle bombardment of a CH4-N2 atmospheric mixture can account for the UV-visible absorbing stratospheric haze, the reddish appearance of the satellite, and some of the C2 hydrocarbons. In the lower atmosphere photochemical processes will be important if surface temperatures are sufficiently high for gaseous NH3 to exist. It is concluded that the surface of Titan may contain ancient or recent organic matter (or both) produced in the atmosphere.

  14. Titanic exploration with GIS

    USGS Publications Warehouse

    Kerski, J.J.

    2004-01-01

    To help teachers and students investigate one of the world's most famous historical events using the geographic perspective and GIS tools and methods, the U.S. Geological Survey (USGS) created a set of educational lessons based on the RMS Titanic's April 1912 sailing. With these lessons, student researchers can learn about latitude and longitude, map projections, ocean currents, databases, maps, and images through the analysis of the route, warnings, sinking, rescue, and eventual discovery of the submerged ocean liner in 1985. They can also consider the human and physical aspects of the maiden voyage in the North Atlantic Ocean at a variety of scales, from global to regional to local. Likewise, their investigations can reveal how the sinking of the Titanic affected future shipping routes.

  15. Crystalline titanate catalyst supports

    SciTech Connect

    Anthony, R.G.; Dosch, R.G.

    1991-12-31

    A series of new crystalline titanates (CT) are shown to have considerable potential as catalyst supports. For Pd supported catalyst, the catalytic activity for pyrene hydrogenation was substantially different depending on the type of CT, and one was substantially more active than Pd on hydrous titanium oxide (HTO). For 1-hexene hydrogenation the activities of the new CTs were approximately the same as for the hydrous metal oxide supports.

  16. Crystalline titanate catalyst supports

    DOEpatents

    Anthony, Rayford G. (Bryan, TX); Dosch, Robert G. (Albuquerque, NM)

    1993-01-01

    A series of new crystalline titanates (CT) are shown to have considerable potential as catalyst supports. For Pd supported catalyst, the catalytic activity for pyrene hydrogenation was substantially different depending on the type of CT, and one was substantially more active than Pd on hydrous titanium oxide (HTO). For 1-hexene hydrogenation the activities of the new CTs were approximately the same as for the hydrous metal oxide supports.

  17. Crystalline titanate catalyst supports

    DOEpatents

    Anthony, R.G.; Dosch, R.G.

    1993-01-05

    A series of new crystalline titanates (CT) are shown to have considerable potential as catalyst supports. For Pd supported catalyst, the catalytic activity for pyrene hydrogenation was substantially different depending on the type of CT, and one was substantially more active than Pd on hydrous titanium oxide (HTO). For 1-hexene hydrogenation the activities of the new CTs were approximately the same as for the hydrous metal oxide supports.

  18. Hydrocarbon lakes on Titan

    Microsoft Academic Search

    Giuseppe Mitri; Adam P. Showman; Jonathan I. Lunine; Ralph D. Lorenz

    2007-01-01

    The Huygens Probe detected dendritic drainage-like features, methane clouds and a high surface relative humidity (?50%) on Titan in the vicinity of its landing site [Tomasko, M.G., and 39 colleagues, 2005. Nature 438, 765–778; Niemann, H.B., and 17 colleagues, 2005. Nature 438, 779–784], suggesting sources of methane that replenish this gas against photo- and charged-particle chemical loss on short (10–100)

  19. Piezoelectric wave motor

    DOEpatents

    Yerganian, Simon Scott (Lee's Summit, MO)

    2001-07-17

    A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

  20. Piezoelectric hydraulic pump performance

    NASA Astrophysics Data System (ADS)

    Mauck, Lisa D.; Oates, William S.; Lynch, Christopher S.

    2001-06-01

    A piezohydraulic pump making use of the step and repeat capability of piezoelectric actuators has been developed for actuation of aircraft control surfaces. The piezohydraulic pump utilizes a piezoelectric stack actuator to drive a piston in a cylinder. The cylinder is fitted with two check valves. On the compression stroke, oil is forced out of the cylinder. On the intake stroke, oil is drawn into the cylinder. The oil is used to drive a linear actuator. The actuator was driven at 7cm/sec with a 271N (61lb) blocking force. To achieve this, the piezoelectric stack actuator was driven at 60Hz with a switching power supply. The system utilizes an accumulator to eliminate cavitation. This work discusses piezohydraulic pumping theory, pump design, and pump performance. Consideration of pump performance includes the effects of varying accumulator pressure, hydraulic oil viscosity, and load imposed on the linear actuator.

  1. Piezoelectric wave motor

    DOEpatents

    Yerganian, Simon Scott (Lee's Summit, MO)

    2003-02-11

    A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase-shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in the direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

  2. Nonlinear ceramics for tunable microwave devices

    Microsoft Academic Search

    Holger Maune; Mohsen Sazegar; Yuliang Zheng; Xianghui Zhou; Andre Giere; Patrick Scheele; Florian Paul; Joachim R. Binder; Rolf Jakoby

    2011-01-01

    The research on materials and systems for tunable microwave devices has gained attraction within the last years. The radio\\u000a frequency characterization and the component design of tunable microwave components based on dielectric ceramics especially\\u000a barium-strontium-titanate (BST) are presented in this second part, whereas the basic material properties are discussed in\\u000a detail in the first part. After a short introduction to

  3. Ceramic diaphragms for advanced alkaline water electrolysis

    Microsoft Academic Search

    H. Wendt; H. Hofmann

    1989-01-01

    Chemically stable and physically strong, but relatively expensive diaphragms with low electrical surface-specific resistance have been developed for alkaline water electrolysis intended to work at temperature around and above 120°C at increased current densities and yet reduced cell voltage. These diaphragms are made of a porous cermet produced from ceramic particles (group 2A titanates) and NiO by reductive sintering. Two

  4. PRODUCT DATA Piezoelectric Accelerometer

    E-print Network

    Phani, A. Srikantha

    element used is a PZ 23 lead zirconate titanate element. The housing material is titanium. Calibration (­-101 to 482) Humidity Welded, sealed Max. Operational Sinusoidal Vibration (peak) g pk 2000 Max Characteristics Dimensions See outline drawing Weight gram (oz.) 17 (0.6) Case Material Titanium Connector 10

  5. Titan's neutral atmospheric composition

    NASA Astrophysics Data System (ADS)

    Coustenis, A.; Jennings, D.; Jolly, A.; Bénilan, Y.; Vinatier, S.; Nixon, C.; Gautier, D.; Bjoraker, G.; Romani, P.; Flasar, M.

    2007-08-01

    Our understanding of Titan's atmospheric chemical composition has recently been enhanced by the data returned by the Cassini instruments. Spectra recorded by the Composite Infrared Spectrometer (CIRS) aboard the Cassini spacecraft have been processed from the Titan flybys spanning three years now since SOI (Flasar et al., 2005; Teanby et al., 2006, Vinatier et al., 2006; Nixon et al., 2006; Coustenis et al., 2007). The spectra characterize various regions on Titan from 85°S to 80°N with a variety of emission angles. We have studied the emission observed in the CIRS detector arrays (covering the 10-1500 cm-1 spectral range with apodized resolutions of 2.54 or 0.53 cm-1). We have used temperature profiles retrieved from the inversion of the emission observed in the methane v4 band at 1304 cm-1 and a line-by-line radiative transfer code to infer the abundances of the trace constituents and some of their isotopes in Titan's stratosphere (Coustenis et al., 2007a). The composite spectra show several signatures of previously identified molecules: hydrocarbons, nitriles, H2O and CO2. Besides these well-known trace species, a firm detection of benzene (C6H6) is provided by CIRS at 674 cm-1 and allows for the study of its latitudinal variations. No longitudinal variations were found for any of the gases. Information is retrieved on the meridional variations of the trace constituents and tied to predictions by dynamicalphotochemical models (Hourdin et al., 2004; Lavvas et al., 2007). Molecules showing a significant enhancement at northern latitudes are the nitriles (HC3N, HCN) and the complex hydrocarbons (C4H2, C3H4). The D/H ratio on Titan was also determined from the CH3D band at 8.6 micron and found to be about 1.3 ±0.2 10-4. We have also identified the presence of C2HD at 678 cm-1 for the first time (Coustenis et al., 2007b, in preparation). Constraints are also set on the vertical distribution of C2H2. References : Coustenis et al., 2007a, Icarus, in press; Flasar et al., 2005, Science 308, 975 ; Hourdin et al., 2004, J. Geophys. Res. 109, E1205; Nixon et al., 2006, BAAS 38; Lavvas et al., 2007, Plan. Space Sci., in press; Teanby et al., 2006, Icarus 181, 243; Vinatier et al., 2006, Icarus, 188, 120.

  6. Geomorphic Units on Titan

    NASA Astrophysics Data System (ADS)

    Lopes, Rosaly; Malaska, Michael; Schoenfeld, Ashley; Birch, Samuel; Hayes, Alexander; Solomonidou, Anezina; Radebaugh, Jani

    2015-04-01

    The Cassini-Huygens mission has revealed the surface of Titan in unprecedented detail. The Synthetic Aperture Radar (SAR) mode on the Cassini Titan Radar Mapper is able to penetrate clouds and haze to provide high resolution (~350 m spatial resolution at best) views of the surface geology. The instrument's other modes (altimetry, scatterometry, radiometry) also provide valuable data for interpreting the geology, as do other instruments on Cassini, in particular, the Imaging Science Subsystem (ISS) and the Visual and Infrared Mapping Spectrometer (VIMS). Continuing the initial work described in Lopes et al. (2010, Icarus, 212, 744-750), we have established the major geomorphologic unit classes on Titan using data from flybys Ta through T92 (October 2004-July 2013). We will present the global distribution of the major classes of units and, where there are direct morphological contacts, describe how these classes of units relate to each other in terms of setting and emplacement history. The classes of units are mountainous/hummocky terrains, plains, dunes, labyrinthic terrains and lakes. The oldest classes of units are the mountainous/hummocky and the labyrinthic terrains. The mountainous/hummocky terrains consist of mountain chains and isolated radar-bright terrains. The labyrinthic terrains consist of highly incised dissected plateaux with medium radar backscatter. The plains are younger than both mountainous/hummocky and labyrinthic unit classes. Dunes and lakes are the youngest unit classes on Titan; no contact is observed between the dunes and lakes but it is likely that both processes are still active. We have identified individual features such as craters, channels, and candidate cryovolcanic features. Characterization and comparison of the properties of the unit classes and the individual features with data from radiometry, ISS, and VIMS provides information on their composition and possible provenance. We can use these correlations to also infer global distribution on regions not covered by SAR. This is particularly important as SAR data will not provide complete coverage of Titan by the end of the Cassini mission.

  7. Composite ceramic-metal plates tested with flexural waves and holography

    Microsoft Academic Search

    M. Conrad; M. Sayir

    2001-01-01

    A method to determine weak or defective bonding areas within the brazed adjoining contact surfaces of composite ceramic-metal plates is proposed. The plates include voids, as well as hairline cracks in the ceramic layer, caused by the high-temperature brazing process. To detect these flaws, transient flexural waves are generated and transmitted through the plate by means of an attached piezoelectric

  8. Improvement of low-frequency characteristics of piezoelectric speakers based on acoustic diaphragms.

    PubMed

    Kim, Hye Jin; Yang, Woo Seok; No, Kwangsoo

    2012-09-01

    The vibrational characteristics of 3 types of the acoustic diaphragms are investigated to enhance the output acoustic performance of the piezoelectric ceramic speaker in a low-frequency range. In other to achieve both a higher output sound pressure level and wider frequency range of the piezoelectric speaker, we have proposed a rubber/resin bi-layer acoustic diaphragm. The theoretical square-root dependence of the fundamental resonant frequency on the thickness and Young's modulus of the acoustic diaphragm was verified by finite-element analysis simulation and laser scanning vibrometer measurement. The simulated resonant frequencies for each diaphragm correspond well to the measured results. From the simulated and measured resonant frequency results, it is found that the fundamental resonant frequency of the piezoelectric ceramic speaker can be designed by adjusting the thickness ratio of the rubber/resin bi-layer acoustic diaphragm. Compared with a commercial piezoelectric speaker, the fabricated piezoelectric ceramic speaker with the rubber/resin bi-layer diaphragm has at least 10 dB higher sound pressures in the low-frequency range of less than 1 kHz. PMID:23007777

  9. Titan's Methane Cycle is Closed

    NASA Astrophysics Data System (ADS)

    Hofgartner, J. D.; Lunine, J. I.

    2013-12-01

    Doppler tracking of the Cassini spacecraft determined a polar moment of inertia for Titan of 0.34 (Iess et al., 2010, Science, 327, 1367). Assuming hydrostatic equilibrium, one interpretation is that Titan's silicate core is partially hydrated (Castillo-Rogez and Lunine, 2010, Geophys. Res. Lett., 37, L20205). These authors point out that for the core to have avoided complete thermal dehydration to the present day, at least 30% of the potassium content of Titan must have leached into an overlying water ocean by the end of the core overturn. We calculate that for probable ammonia compositions of Titan's ocean (compositions with greater than 1% ammonia by weight), that this amount of potassium leaching is achievable via the substitution of ammonium for potassium during the hydration epoch. Formation of a hydrous core early in Titan's history by serpentinization results in the loss of one hydrogen molecule for every hydrating water molecule. We calculate that complete serpentinization of Titan's core corresponds to the release of more than enough hydrogen to reconstitute all of the methane atoms photolyzed throughout Titan's history. Insertion of molecular hydrogen by double occupancy into crustal clathrates provides a storage medium and an opportunity for ethane to be converted back to methane slowly over time--potentially completing a cycle that extends the lifetime of methane in Titan's surface atmosphere system by factors of several to an order of magnitude over the photochemically-calculated lifetime.

  10. Titan Tusk Force Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Tusk Force Student Engagement Report FY 2008-2009 Mission Statement The mission of Titan Tusk Force is to develop a strong sense of campus unity, pride and identity with CSUF. Titan Tusk Force, Incorporated here at California State University, Fullerton. Program Overview Titan Tusk Force (TTF) functions

  11. Titan Parents Association Scholarship Spring 2012

    E-print Network

    de Lijser, Peter

    Titan Parents Association Scholarship Spring 2012 Amount: $500 Established by: Titan Parents Association This program was established by the Cal State Fullerton Titan Parents Association. Scholarship campaigns and Titan Parents programs and events. Funds must be used for the upcoming academic semester

  12. Titan Tusk Force Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Tusk Force Student Engagement Report FY 2009-2010 Mission Statement The mission of Titan Tusk Force is to develop a strong sense of campus unity, pride and identity with CSUF. Titan Tusk Force, Incorporated here at California State University, Fullerton. Program Overview Titan Tusk Force (TTF) functions

  13. Titan Tusk Force Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Tusk Force Student Engagement Report FY 2011-2012 Mission Statement The mission of Titan Tusk Force is to develop a strong sense of campus unity, pride and identity with CSUF. Titan Tusk Force, Incorporated here at California State University, Fullerton. Program Overview Titan Tusk Force (TTF) functions

  14. Titan Tusk Force Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Tusk Force Student Engagement Report FY 2010-2011 Mission Statement The mission of Titan Tusk Force is to develop a strong sense of campus unity, pride and identity with CSUF. Titan Tusk Force, Incorporated here at California State University, Fullerton. Program Overview Titan Tusk Force (TTF) functions

  15. Piezoelectric sensor based nondestructive active monitoring of strength gain in concrete

    NASA Astrophysics Data System (ADS)

    Shin, Sung Woo; Riaz Qureshi, Adeel; Lee, Jae-Yong; Bang Yun, Chung

    2008-10-01

    The recent advent of smart materials, such as piezoelectric materials, shape-memory alloys, and optical fibers, has added a new dimension to present structural health monitoring techniques. In particular, the electro-mechanical impedance (EMI) sensing technique utilizing piezoelectric materials has emerged as a potential tool for the implementation of a built-in monitoring system for damage detection of civil structures. However, there is little effort to apply this technique for concrete monitoring. In this study, an effort to extend the applicability of the EMI sensing technique is made for strength gain monitoring of early age concrete. PZT (piezoelectric lead zirconate titanate) patches are employed to sense the EMI signature of curing concrete. A series of experiments was conducted on concrete specimens to verify the applicability of the EMI sensing technique. The results show the excellent potential of the EMI sensing technique as a practical and reliable nondestructive method for strength gain monitoring.

  16. The commercial Titan launch vehicle

    NASA Astrophysics Data System (ADS)

    Troutman, J.; Isakowitz, S.

    1987-06-01

    Martin Marietta is making available a commercial version of the Titan launch vehicle. At a total payload weight capability of 31,600 pounds to low earth orbit, the commercial Titan provides Shuttle and Ariane compatible services to the commercial satellite community. This paper describes the commercial Titan which is based on the U.S. Air Force Titan 34D. A large diameter payload fairing and extension module provide for single or dual payload installation. Structural and some equipment rearrangement modifications have been made to the Stage II forward skirt to handle the larger payload fairing and loads involved in commercial operation. Stage II has been stretched and the liquid rocket engines enhanced to improve lift performance. The solid rocket motors and avionics remain unchanged. Plans to utilize Transtage on top a Titan III for direct injection into geosynchronous transfer orbit are being studied for future launches.

  17. Muscular PiezoElectricity?

    Microsoft Academic Search

    F. Buchanan

    1921-01-01

    THE well-known ``action current'' of muscle can have nothing to do with piezo-electricity, since it may reach its maximum before any mechanical change begins. Nor do I see anything to suggest the occurrence of such electricity in other animal tissues or organs. Mr. Wriothesley Russell (NATURE, October 27, p. 275) might, however, find plants worth investigating for evidence of it.

  18. Characterization of dissipation factors in terms of piezoelectric equivalent circuit parameters.

    PubMed

    Chen, Yu; Wen, Yumei; Li, Ping

    2006-12-01

    The equivalent circuit of a piezoelectric ceramic is established composed of the equivalent circuit parameters derived from the complex materials coefficients. The equivalent circuit parameters are connected to real and imaginary parts of the complex materials coefficients of the piezoelectric ceramics. With respect to the definition of dissipation factors, the dielectric, elastic, and piezoelectric dissipation factors which represent the losses in the materials are thus expressed through the equivalent circuit parameters. In temperature and stress experiments, by measuring the equivalent circuit parameters during the process of the temperature and stress changes, three dissipation factors are computed. Compared with the results of other previous research, a similar increase of the elastic dissipation factor with stress is observed. Moreover, it is also found that the elastic dissipation factor reaches its saturation over a stress level of about 10 MPa. The responses of dissipation factors in lower temperature (-30 degrees C to 20 degrees C) are studied. PMID:17186919

  19. Enhanced dielectric properties from barium strontium titanate films with strontium titanate buffer layers

    E-print Network

    Alpay, S. Pamir

    Enhanced dielectric properties from barium strontium titanate films with strontium titanate buffer in their PE state. One of the leading material candidates for tunable materials is barium strontium titanate

  20. Zinc titanate sorbents

    DOEpatents

    Gupta, R.P.; Gangwal, S.K.; Jain, S.C.

    1998-02-03

    The present invention provides a zinc titanate sorbent material useful in desulfurization applications. The zinc titanate material is in the form of generally spherical particles of substantially uniform chemical distribution. The sorbent material is capable of absorbing sulfur compounds from a gaseous feed in an amount of at least about 15 weight percent based on the weight of the sorbent. The sorbent material is prepared by a process including: (a) forming a zinc oxide/titanium dioxide dry blend, (b) preparing a substantially uniform aqueous slurry comprising the zinc oxide/titanium dioxide dry blend, organic binder, and at least about 1 weight percent inorganic binder based on the solids weight of the slurry, (c) spray drying the slurry to produce substantially spherical particles, and (d) calcining the particles at a temperature of between about 750 to about 950 C. The dry blend is formed by mixing between about 0.5 to about 2 parts zinc oxide having a median particle size of less than about 0.5 microns, and about 1 part titanium dioxide having a median particle size of less than about 1 micron. The slurry contains substantially no free silica and may be prepared by the process including (1) preparing an aqueous solution of organic binder, (2) adding the dry blend to the aqueous solution of organic binder, and (3) adding the inorganic binder to the solution of organic binder, and blend. Additional reagents, such as a surfactant, may also be incorporated into the sorbent material. The present invention also provides a process for desulfurizing a gaseous stream. The process includes passing a gaseous stream through a reactor containing an attrition resistant zinc titanate sorbent material of the present invention.