Sample records for zirconate titanate pzt

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

    NASA Astrophysics Data System (ADS)

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

    2010-04-01

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

  2. Effects of microstructure on the properties of ferroelectric lead zirconate titanate (PZT) thin films

    NASA Astrophysics Data System (ADS)

    Goh, W. C.; Yao, K.; Ong, C. K.

    2005-10-01

    Lead zirconate titanate (PZT) thin films were prepared with pulsed laser deposition and sol gel techniques. The PZT films fabricated by these two techniques have similar randomly oriented single perovskite phases, but the film derived from the pulsed laser deposition exhibits a more compact and flat morphology. The dielectric, ferroelectric, and piezoelectric properties of the two kinds of films are comparatively characterized and discussed. It is observed that a denser microstructure would lead to a significantly higher dielectric constant and remanent polarization and a much lower coercive electric field, but only a relatively slight enhancement on the piezoelectric constant. The film with a looser microstructure could have a substantially higher piezoelectric voltage constant g33 due to the much lower dielectric constant. Our results and discussion provide a better understanding of the relationship between the microstructure and the film properties, which is essential in order to tailor the microstructure and hence determine the performance aiming at a specific application.

  3. Development of sol-gel derived lead zirconate titanate (PZT) thin films with a nonporous Pt/Ti bottom electrode

    NASA Astrophysics Data System (ADS)

    Guo, Qing; Cao, G. Z.; Shen, I. Y.

    2011-04-01

    Lead Zirconate Titanate Oxide (PbZrxTi1-xO3 or PZT) thin films have been widely used in various microsensors and microactuators for their high bandwidth and sensitivity. A typical configuration is to use a Pt/Ti bi-layer as the bottom electrode. Before the PZT film is deposited, Pt/Ti bi-layer must be annealed at high temperature (e.g., 800°C) to obtain a condensed structure with a rough micro surface texture. A condensed Pt/Ti structure prevents delamination of the bottom electrode, while a rough micro surface texture ensures PZT thin films anchored firmly onto the bottom electrodes. Although the annealing process is necessary, its high temperature causes Pt/Ti bi-layer to become porous, thus degrading electrical and ferroelectric properties of the PZT thin films. In this paper, we present a non-porous Pt/Ti bottom electrode via a two-step deposition and annealing process. The first step is the traditional fabrication process that leads to a porous Pt/Ti electrode. A second round of deposition and annealing then seals the pores and strengthens the electrode. To evaluate the performance of the non-porous bottom electrode, PZT thin films with porous and non-porous bottom electrodes are fabricated simultaneously. Experimental measurements show that piezoelectric constant d33 of the PZT film increases from 10 pC/N to 20 pC/N when the bottom electrode is changed from the porous to non-porous electrode.

  4. Lead zirconate titanate ceramics

    SciTech Connect

    Walker, B.E. Jr.

    1986-12-02

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

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

    NASA Astrophysics Data System (ADS)

    Berfield, Thomas A.

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

  7. RF sputtered lead zirconate titanate (PZT) film capacitor with a multilayer construction

    SciTech Connect

    Tsao, B.H.; Carr, S.F.; Weimer, J.A.

    1998-07-01

    Thin PZT film is being developed for use in microelectronics, electromechanical and optoelectronic applications. Thin Pb(ZrTi)O{sub 3} film capacitor devices were fabricated using RF sputtering techniques. The multiple-layer configuration of Si/SiO{sub 2}/Ti/Pd or Pt was used as the substrate and bottom electrode. The top electrode was either Pd or Pt. At room temperature, the typical dissipation factor of this PZT film capacitor was 0.083 at 1 kHz. These PZT film capacitors had a parallel resistance of 1.15 mega-ohm. The film capacitor has an energy storage density of 0.023 {micro}F/cm{sup 2} . With the thickness of the film being 12,000 {angstrom}, the dielectric constant was calculated to be 32. The insulation resistance was 138 giga-ohm. The resistivity was calculated to be 8.1 {times} 10{sup 10} ohm-cm. These film capacitors were tested at 50 volts and the corresponding leakage current was at 1{times}10 {sup {minus}5} amp/cm{sup 2} . The breakdown strength at this stage was 4.2{times}10{sup 5} V/cm. Annealing at 400 C increased the value of the dielectric constant about 38%. The dissipation factor was decreased to 0.023 at 1 kHz. The parallel resistance increased from 1.15 to 3.01 mega-ohm. The insulation resistance after annealing was increased to 2180 giga-ohm. The resistivity was increased to 1.28{times}10{sup 13} ohm-cm. The energy storage density of this film capacitor was increased from 0.023 to 0.031 {micro}F/cm{sup 2} . These film capacitors produced to-date had little dependence on frequency from 400 Hz to 100 kHz. The PZT sample with a thickness of 4.2 {micro}m exhibited a dielectric constant of 107 before annealing and 354 after annealed at 600 C. The dissipation factor was reduced from 0.12 to 0.015 before and after annealing at 600 C.

  8. Nanoshell tubes of ferroelectric lead zirconate titanate and barium titanate Yun Luo, Izabela Szafraniak, and Nikolai D. Zakharov

    E-print Network

    Ramesh, R.

    Nanoshell tubes of ferroelectric lead zirconate titanate and barium titanate Yun Luo, Izabela templates, barium titanate and lead zirconate titanate tubes with diameters ranging from 50 nm up to several (PbZr0.52Ti0.48O3 ,PZT) and barium titanate (BaTiO3 ,BTO) nanotubes were fabricated by using

  9. Nonlinear electric field tuning characteristics of yttrium iron garnetlead zirconate titanate microwave resonators

    E-print Network

    Srinivasan, Gopalan

    crystals of barium ferrite that have high uniaxial magnetic anisotropy. Lead zirconium titanate PZT or leadNonlinear electric field tuning characteristics of yttrium iron garnet­lead zirconate titanate in a bilayer of yttrium iron garnet YIG -lead zirconate titanate PZT . The tuning is facilitated

  10. Resonance magnetoelectric interactions due to bending modes in a nickel-lead zirconate titanate bilayer

    E-print Network

    Srinivasan, Gopalan

    systems with transition metals or al- loys and PZT, barium titanate or lead magnesium niobate- leadResonance magnetoelectric interactions due to bending modes in a nickel-lead zirconate titanate investigated in bilayers of Ni and lead zirconate titanate PZT . For nominal sample dimensions

  11. Direct printing of lead zirconate titanate thin films

    E-print Network

    Bathurst, Stephen, 1980-

    2008-01-01

    Thus far, use of lead zirconate titanate (PZT) in MEMS has been limited due to the lack of process compatibility with existing MEMS manufacturing techniques. Direct printing of thin films eliminates the need for photolithographic ...

  12. A smart, intermittent driven particle sensor with an airflow change trigger using a lead zirconate titanate (PZT) cantilever

    NASA Astrophysics Data System (ADS)

    Takahashi, Hidetoshi; Tomimatsu, Yutaka; Kobayashi, Takeshi; Isozaki, Akihiro; Itoh, Toshihiro; Maeda, Ryutaro; Matsumoto, Kiyoshi; Shimoyama, Isao

    2014-02-01

    This paper reports on a smart, intermittent driven particle sensor with an airflow trigger. A lead zirconate titanate cantilever functions as the trigger, which detects an airflow change without requiring a power supply to drive the sensing element. Because an airflow change indicates that the particle concentration has changed, the trigger switches the optical particle counter from sleep mode to active mode only when the particle concentration surrounding the sensor changes. The sensor power consumption in sleep mode is 100 times less than that in the active mode. Thus, this intermittent driven method significantly reduces the total power consumption of the particle sensor. In this paper, we fabricate a prototype of the particle sensor and demonstrate that the optical particle counter can be switched on by the fabricated trigger and thus that the particle concentration can be measured.

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

    E-print Network

    Srinivasan, Gopalan

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

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

    E-print Network

    Cao, Wenwu

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

  15. Hydrothermal synthesis of vertically aligned lead zirconate titanate nanowire arrays

    NASA Astrophysics Data System (ADS)

    Lin, Yirong; Liu, Yingtao; Sodano, Henry A.

    2009-09-01

    A hydrothermal method is employed for the growth of single crystal vertically aligned lead zirconate titanate (PZT) nanowire arrays. The resulting PZT nanowires were grown from a TiO2 film and are shown to be single crystal with growth in the [110] axis. PZT has a coupling coefficient up to two orders of magnitude higher than ZnO, which should provide many opportunities for the creation of active nanodevices and systems.

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

    E-print Network

    Srinivasan, Gopalan

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

  17. Fabrication, Electrical, and Material Characterization of Lead Zirconate Titanate Thin Film Capacitors for Semiconductor Memory Applications

    Microsoft Academic Search

    Vinay B. Chikarmane

    1992-01-01

    In this work, ferroelectric lead zirconate titanate (PZT) thin film capacitors with charge storage densities that exceeds the requirements of 256 Mb DRAM storage dielectric applications have been successfully developed. The excellent electrical properties of PZT thin film capacitors fabricated with Pt electrodes indicate that PZT might be an attractive candidate for storage applications in ULSI semiconductor memories. The electrical

  18. Dielectric behaviors of lead zirconate titanate ceramics with coplanar electrodes

    Microsoft Academic Search

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

    2003-01-01

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

  19. Millimeter-wave magnetoelectric effects in bilayers of barium hexaferrite and lead zirconate titanate

    E-print Network

    Srinivasan, Gopalan

    excitations in bilayers of single crystal barium ferrite and lead zirconate titanate PZT . An electric field EMillimeter-wave magnetoelectric effects in bilayers of barium hexaferrite and lead zirconate titanate G. Srinivasan,a I. V. Zavislyak, and A. S. Tatarenko Physics Department, Oakland University

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

    Microsoft Academic Search

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

    2001-01-01

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

  1. Stochastic ferroelectric switching of lead zirconate titanate thin films

    NASA Astrophysics Data System (ADS)

    Marino, S.; Lepreti, F.; Carbone, V.; Scaramuzza, N.

    2010-04-01

    We investigate the repolarization phenomenon in a ferroelectric film. Our ferroelectric sample was lead zirconate titanate (PZT) obtained by sol-gel synthesis and deposited by spin coating on ITO/glass substrate. A series of repolarizations were induced in the ferroelectric film by applying a triangular wave and the current peaks related to the switchings of the ferroelectric domains were acquired for statistical analyses. It is shown that the dynamics and statistics of polarization switchings are well simulated by a simple mean-field model in which a double-well, asymmetric potential is included to describe the asymmetry at the PZT-ITO interface.

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

    SciTech Connect

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

    2008-04-15

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

  3. 1.6 V Nanogenerator for Mechanical Energy Harvesting Using PZT Nanofibers

    E-print Network

    titanate (PZT),13 cadmium sulfide,14 barium titanate,15 and gallium nitride16 have been success- fully nanogenerators7­12 is lower than that of lead zirconate titanate (PZT) nanomaterials. Here we report application to the soft polymer was 1.63 V and 0.03 µW, respectively. KEYWORDS Lead zirconate titanate (PZT

  4. Magnetically Enhanced Reactive Ion Etching of Lead Zirconate Titanate Thin Film by CHF3 Plasma

    Microsoft Academic Search

    Yin-yin Lin; Qin Liu; Ting-ao Tang; Xi Yao; Wei-ning Huang

    2000-01-01

    A metal-organic deposition (MOD) derived Pb (Zr0.53Ti0.47)O3 thin film was patterned using magnetically enhanced reactive ion etching (MERIE) which promised a relatively high etching rate, large etch anisotropy and good selectivity for lead zirconate titanate (PZT). The etched surface of PZT thin films was investigated by X- ray photoelectron spectroscopy (XPS). It was found that PbF2, ZrF4 and polymers containing

  5. Dielectric behavior and magnetoelectric properties of lead zirconate titanate\\/Co-ferrite particulate composites

    Microsoft Academic Search

    Jun Yi Zhai; Ning Cai; Li Liu; Yuan Hua Lin; Ce Wen Nan

    2003-01-01

    Magnetoelectric (ME) composites of lead zirconate titanate (PZT) and Co-ferrite with various compositions were prepared by using conventional ceramic sintering process. The variation of dielectric behavior of the composites with frequency in the range of 100 Hz to 1 MHz at room temperature was studied. The ME coefficient was investigated at various bias fields and frequency. The maximum ME voltage

  6. Nanoshell tubes of ferroelectric lead zirconate titanate and barium titanate

    Microsoft Academic Search

    Yun Luo; Izabela Szafraniak; Nikolai D. Zakharov; Valanoor Nagarajan; Martin Steinhart; Ralf B. Wehrspohn; Joachim H. Wendorff; Ramamoorthy Ramesh; Marin Alexe

    2003-01-01

    Wafer-scale fabrication of ferroelectric oxide nanoshell tubes as well as ordered nanotube arrays have been accomplished using a simple and convenient fabrication method that allows full tailoring of tube dimensions as well as array pattern and size. Using different silicon and alumina templates, barium titanate and lead zirconate titanate tubes with diameters ranging from 50 nm up to several micrometers

  7. Relationship between orientation factor of lead zirconate titanate nanowires and dielectric permittivity of nanocomposites

    SciTech Connect

    Tang, Haixiong, E-mail: htang15@ufl.edu, E-mail: hsodano@ufl.edu [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); Malakooti, Mohammad H. [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611 (United States)] [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611 (United States); Sodano, Henry A., E-mail: htang15@ufl.edu, E-mail: hsodano@ufl.edu [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611 (United States)

    2013-11-25

    The relationship between the orientation of lead zirconate titanate (PZT) nanowires dispersed in nanocomposites and the resulting dielectric constants are quantified. The orientation of the PZT nanowires embedded in a polymer matrix is controlled by varying the draw ratio and subsequently quantified using Herman's Orientation Factor. Consequently, it is demonstrated that the dielectric constants of nanocomposites are improved by increasing the orientation factor of the PZT nanowires. This technique is proposed to improve the dielectric constant of the nanocomposites without the need for additional filler volume fraction since the nanocomposites are utilized in a wide range of high dielectric permittivity electronic components.

  8. Pyrochlore to perovskite phase transformation in sol-gel derived lead-zirconate-titanate thin films

    NASA Astrophysics Data System (ADS)

    Kwok, Chi Kong; Desu, Seshu B.

    1992-03-01

    Pyrochlore to perovskite phase transformation in sol-gel derived lead-zirconate-titanate (PZT) films was studied by x-ray diffraction and transmission-electron microscopy (TEM). X-ray diffraction studies of PZT films on sapphire substrates indicated that the pyrochlore to perovskite phase transformation was completed at 650 °C. In contrast, TEM investigations of free-standing PZT films showed that the phase transformation was completed at much higher temperatures. This discrepancy in the behavior of free-standing films versus films on substrate can be related to the size effect.

  9. Dielectric and pyroelectric properties of lead zirconate titanate/polyurethane composites

    SciTech Connect

    Lam, K.S.; Wong, Y.W.; Tai, L.S.; Poon, Y.M.; Shin, F.G. [Department of Applied Physics, Hong Kong Polytechnic University, Hung Hom, Hong Kong (China)

    2004-10-01

    0-3 composite ranging between 0 and 3, of ferroelectric ceramic lead zirconate titanate (PZT) and thermoplastic elastomer polyurethane (PU) were fabricated. The pyroelectric and dielectric properties of the hot-pressed thin film samples of various PZT volume fractions were measured. The experimental dielectric permittivities and losses agreed reasonably well with the Bruggeman model. The room temperature pyroelectric coefficients of the composites were found to increase linearly with PZT volume fraction and substantially larger than expected. For example, for a composite with 30% PZT, its pyroelectric coefficient is about 90 {mu}C/m{sup 2}K at room temperature, which is more than tenfold of a PZT/PVDF composite of the same ceramic volume fraction. We propose a model in which the electrical conductivity of the composite system is taken into consideration to explain the linear relationship and the extraordinarily large pyroelectric coefficients obtained.

  10. Optimization of PZT processing using thermal ink-jet printing

    E-print Network

    Jeon, Jessie Sungyun

    2008-01-01

    Lead zirconate titanate (PZT) has been known for its strong piezoelectric property for micro-sensors and actuators. Yet, its use in MEMS has been constrained by limitations in processing PZT with current MEMS fabrication ...

  11. Giant magnetoelectric effects in layered composites of nickel zinc ferrite and lead zirconate titanate

    Microsoft Academic Search

    G. Srinivasan; V. M. Laletsin; R. Hayes; N. Puddubnaya; E. T. Rasmussen; D. J. Fekel

    2002-01-01

    A 40-fold increase in the strength of magnetoelectric (ME) coupling is reported in layered samples of nickel ferrite (NFO)–lead zirconate titanate (PZT) compared to bulk composites. In bulk samples, the transverse and longitudinal couplings are weak and are of equal magnitude. The ME coupling strengthens by an order of magnitude when high-resistivity modified-NFO is used in the composite. A further

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

    Microsoft Academic Search

    Nersesse Nersessian; Siu Wing; G. P. Carman

    2004-01-01

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

  13. Pb nanowire formation on Al/lead zirconate titanate surfaces in high-pressure hydrogen

    SciTech Connect

    Alvine, Kyle J.; Shutthanandan, V.; Arey, Bruce W.; Wang, Chong M.; Bennett, Wendy D.; Pitman, Stan G.

    2012-07-12

    Thin films of Al on lead zirconate titanate (PZT) annealed in high-pressure hydrogen at 100C exhibit surface Pb nanowire growth. Wire diameter is approximately 80 nm and length can exceed 100 microns. Based on microstructural analysis using electron microscopy and ion scattering, a vapor-solid scheme with hydrogen as a carrier gas was proposed as a growth mechanism. We expect that these observations may lead to controlled Pb nanowires growth through pattering of the Al film.

  14. Magnetoelectric effects in bilayers of lead zirconate titanate and single crystal hexaferrites

    Microsoft Academic Search

    V. L. Mathe; G. Srinivasan; A. M. Balbashov

    2008-01-01

    Magnetostrictive-piezoelectric heterostructures show strong magnetoelectric (ME) interactions that are mediated by mechanical forces. The effect, in general, vanishes when magnetostriction saturates at high bias magnetic fields (H). Here, we report strong ME effects for H as high as 18 kOe in bilayers of lead zirconate titanate (PZT) and single-crystal hexagonal M-, Y-, or Z-type ferrites. Studies on Sr–Al–M, Zn2Y, or

  15. Magnetoelectric effects in bilayers of lead zirconate titanate and single crystal hexaferrites

    Microsoft Academic Search

    V. L. Mathe; G. Srinivasan; A. M. Balbashov

    2008-01-01

    Magnetostrictive-piezoelectric heterostructures show strong magnetoelectric (ME) interactions that are mediated by mechanical forces. The effect, in general, vanishes when magnetostriction saturates at high bias magnetic fields (H). Here, we report strong ME effects for H as high as 18 kOe in bilayers of lead zirconate titanate (PZT) and single-crystal hexagonal M-, Y-, or Z-type ferrites. Studies on Sr-Al-M, Zn2Y, or

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

    SciTech Connect

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

    2009-04-15

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

  17. Niobium doped lead zirconate titanate films for infrared sensor application

    NASA Astrophysics Data System (ADS)

    Han, Hui

    Nb-doped lead zirconate titanate with formula Pb1-x/2 Nbx(Zr0.2Ti0.8)1-xO 3 (x=0, 0.01, 0.02, 0.03, 0.04, and abbreviated as PNZT) films with two thicknesses: one of approximately 200 nm and the other of 1 mum, were grown on platinized silicon (Pt/TiOx/SiO2/Si) substrates using the method of chemical solution deposition. These chemical precursors were prepared in-house, and through careful control of the processing procedures high quality films were grown. All the films exhibit highly preferred (111) orientation without any presence of the impurity phase. We systematically investigated the Nb doping effect on the electrical properties of PZT films. Results indicate that Nb belongs to a class of soft dopants for lead zirconate titanate films, and as a result it increases the ferroelectric polarization, pyroelectric coefficient, dielectric constant and tan delta loss. In the capacitors with the configuration of Pt/PNZT/Pt, the leakage current at low electric fields is dominated by the interface-controlled Schottky emission, whereas bulk-controlled Frenkel-Poole emission dominates at high electric fields. Nb-doping up to 2 atomic % can remarkably suppress the Frenkel-Poole emission process. The suppression of mobile oxygen vacancies by Nb donor dopants lowered the leakage current and increases the domain wall mobility. Study also shows that 1% Nb doped PZT films exhibit the highest pyroelectric coefficient, figure of merit and voltage response among all the samples. Therefore these films with such superior properties are potential candidates for applications, especially for fabrication of uncooled pyroelectric IR sensors with better performance.

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-11-01

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

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

    NASA Astrophysics Data System (ADS)

    Tang, Liguo; Cao, Wenwu

    2015-02-01

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

  2. Magnetoelectric effects in ferrite-lead zirconate titanate layered composites: The influence of zinc substitution in ferrites

    Microsoft Academic Search

    G. Srinivasan; E. T. Rasmussen; R. Hayes

    2003-01-01

    The observation of strong magnetoelectric (ME) coupling is reported in zinc-substituted layered composites of ferrites and lead zirconate titanate (PZT). Multilayer samples contained cobalt zinc ferrite Co1-xZnxFe2O4 (CZFO) (x=0 0.6) or nickel zinc ferrite Ni1-xZnxFe2O4 (NZFO) (x=0 0.5) and were prepared by laminating and sintering ferrite and PZT thick films obtained by tape casting. The ME voltage coefficient alphaE was

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

    NASA Astrophysics Data System (ADS)

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

    2009-05-01

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

  4. Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Lee, Sung-Min; Wang, James L.; Lin, Hua-Tay

    2014-12-01

    Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 108 cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and the fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications, such as piezoelectric fuel injectors in heavy-duty diesel engines.

  5. Low temperature crystallization of lead zirconate titanate thin films by a sol-gel method

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Zhang, Q.; Whatmore, R. W.

    1999-05-01

    Pyroelectric lead zirconate titanate (PZT) thin films have been prepared by a sol-gel method and characterized by x-ray diffraction and transmission electron microscopy (TEM). A metastable Pt3Pb intermetallic phase has been identified. The formation of this metastable phase was found to depend on the drying temperature, the thickness of the as-deposited film, annealing temperature, and annealing time. Perovskite PZT was found to nucleate on top of the intermetallic phase, rather than directly on Pt. The improved lattice match between the intermetallic (a0=4.05 Å) and perovskite PZT(a0=4.035 Å) as compared to between Pt(a0=3.9231 Å) and the perovskite is believed to substantially reduce the activation energy for the nucleation of perovskite on Pt. Using this effect, (111) perovskite PZT has been grown at a temperature as low as 440 °C. The formation of the intermetallic phase is believed to facilitate the (111) film orientation. The growth kinetics of the PZT were analyzed using the Avrami model, and from this, the crystallization activation energy was determined as 179 kJ/mol for the phase transformation from pyrochlore to perovskite for this materials system. TEM examination and measurement of electrical property indicated that the films crystallized at 480 °C were good quality, with a pyroelectric coefficient of 1.8×10-4 C m-2 K-1 and a remnant polarization of 24 ?C m-2.

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

    E-print Network

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

  7. 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.

  8. Hydrogen diffusion in lead zirconate titanate and barium titanate

    NASA Astrophysics Data System (ADS)

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

    2012-08-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-11-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1995-04-01

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

  11. Fatigue responses of lead zirconate titanate stacks under semibipolar electric cycling with mechanical preload

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Cooper, Thomas A.; Lin, Hua-Tay; Wereszczak, Andrew A.

    2010-10-01

    Lead zirconate titanate (PZT) stacks that had an interdigital internal electrode configuration were tested to more than 108 cycles. A 100 Hz semibipolar sine wave with a field range of +4.5/-0.9 kV/mm was used in cycling with a concurrently-applied 20 MPa preload. Significant reductions in piezoelectric and dielectric responses were observed during the cycling depending on the measuring condition. Extensive partial discharges were also observed. These surface events resulted in the erosion of external electrode and the exposure of internal electrodes. Sections prepared by sequential polishing technique revealed a variety of damage mechanisms including delaminations, pores, and etch grooves. The scale of damage was correlated with the degree of fatigue-induced reduction in piezoelectric and dielectric responses. The results from this study demonstrate the feasibility of using a semibipolar mode to drive a PZT stack under a mechanical preload and illustrate the potential fatigue and damages of the stack in service.

  12. Interactions between lead-zirconate titanate, polyacrylic acid, and polyvinyl butyral in ethanol and their influence on electrophoretic deposition behavior.

    PubMed

    Kuscer, Danjela; Bakari?, Tina; Kozlev?ar, Bojan; Kosec, Marija

    2013-02-14

    Electrophoretic deposition (EPD) is an attractive method for the fabrication of a few tens of micrometer-thick piezoelectric layers on complex-shape substrates that are used for manufacturing high-frequency transducers. Niobium-doped lead-zirconate titanate (PZT Nb) particles were stabilized in ethanol using poly(acrylic acid) (PAA). With Fourier-transform infrared spectroscopy (FT-IR), we found that the deprotonated carboxylic group from the PAA is coordinated with the metal in the perovskite PZT Nb structure, resulting in a stable ethanol-based suspension. The hydroxyl group from the polyvinyl butyral added into the suspension to prevent the formation of cracks in the as-deposited layer did not interact with the PAA-covered PZT Nb particles. PVB acts as a free polymer in ethanol-based suspensions. The electrophoretic deposition of micro- and nanometer-sized PZT Nb particles from ethanol-based suspensions onto electroded alumina substrates was attempted in order to obtain uniform, crack-free deposits. The interactions between the PZT Nb particles, the PAA, and the PVB in ethanol will be discussed and related to the properties of the suspensions, the deposition yield and the morphology of the as-deposited PZT Nb thick film. PMID:23025567

  13. Growth of lead zirconate titanate thin films by hybrid processing: sol gel method and pulsed-laser deposition

    NASA Astrophysics Data System (ADS)

    Wang, Zhan Jie; Kokawa, Hiroyuki; Maeda, Ryutaro

    2004-02-01

    Lead zirconate titanate (Pb(Zr xTi 1- x)O 3: PZT) thin films were prepared on Pt/Ti/SiO 2/Si substrates by hybrid processing: sol-gel method and pulsed-laser deposition (PLD). X-ray diffraction analysis indicated that the PZT films mainly had a perovskite-type structure with (1 0 0)-preferred orientation, and no peak corresponding to pyrochlore was detected. The transmission electron microscopy image showed that the films had a polycrystalline columnar microstructure extending through the thickness of the film, and no sharp interface was observed between the layers obtained by the sol-gel method and PLD. The HTEM image also revealed that the crystalline lattice of the layers was continuous and there was no difference in crystalline orientation between the layers obtained by the sol-gel method and PLD. These results indicated that the lower PZT layer deposited by the sol-gel method acted as a seed layer for the crystallization of the upper PZT layer deposited by PLD. The solid-phase epitaxial effect between the PZT layers deposited by the sol-gel method and PLD lowers the temperature of postdeposition annealing, and the preferred orientation of the PZT films can be controlled using the layer deposited by the sol-gel method.

  14. Thickness dependence of structural and electrical properties in epitaxial lead zirconate titanate films

    E-print Network

    Alpay, S. Pamir

    speed, the ``activation field,'' was identified by Merz in his pioneering work on barium titanate singleThickness dependence of structural and electrical properties in epitaxial lead zirconate titanate of misfit strain on the microstructure and properties of ferroelectric lead zirconate titanate thin films

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

    SciTech Connect

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

    2012-01-01

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

  16. Substrate Clamping Effects on Irreversible Domain Wall Dynamics in Lead Zirconate Titanate Thin Films

    SciTech Connect

    Griggio, Flavio [ORNL; Jesse, Stephen [ORNL; Kumar, Amit [ORNL; Ovchinnikov, Oleg S [ORNL; Kim, H. [Pennsylvania State University, University Park, PA; Jackson, T. N. [Pennsylvania State University, University Park, PA; Damjanovic, Dragan [ORNL; Kalinin, Sergei V [ORNL; Trolier-Mckinstry, Susan E [ORNL

    2012-01-01

    The role of long-range strain interactions on domain wall dynamics is explored through macroscopic and local measurements of nonlinear behavior in mechanically clamped and released polycrystalline lead zirconate-titanate (PZT) films. Released films show a dramatic change in the global dielectric nonlinearity and its frequency dependence as a function of mechanical clamping. Furthermore, we observe a transition from strong clustering of the nonlinear response for the clamped case to almost uniform nonlinearity for the released film. This behavior is ascribed to increased mobility of domain walls. These results suggest the dominant role of collective strain interactions mediated by the local and global mechanical boundary conditions on the domain wall dynamics. The work presented in this Letter demonstrates that measurements on clamped films may considerably underestimate the piezoelectric coefficients and coupling constants of released structures used in microelectromechanical systems, energy harvesting systems, and microrobots.

  17. Fatigue and failure responses of lead zirconate titanate multilayer actuator under unipolar high-field electric cycling

    SciTech Connect

    Zeng, Fan W [ORNL; Wang, Hong [ORNL; Lin, Hua-Tay [ORNL

    2013-01-01

    Lead zirconate titanate (PZT) multilayer actuators with an interdigital electrode design were studied under high electric fields (3 and 6 kV/mm) in a unipolar cycling mode. A 100 Hz sine wave was used in cycling. Five specimens tested under 6 kV/mm failed from 3.8 10^5 to 7 10^5 cycles, whereas three other specimens tested under 3 kV/mm were found to be still functional after 10^8 cycles. Variations in piezoelectric and dielectric responses of the tested specimens were observed during the fatigue test, depending on the measuring and cycling conditions. Selected fatigued and damaged actuators were characterized using an impedance analyzer or small signal measurement. A scanning acoustic microscope also was employed as a nondestructive tool to detect the presence of defects. Failed plates were subsequently sectioned, and the extensive cracks and porous regions were observed to be across the PZT layers. The results from this study have demonstrated that the high-field cycling can accelerate the fatigue of PZT stacks as long as the partial discharge is controlled. The small signal measurement can also be integrated into the large signal measurement to characterize the fatigue response of PZT stacks in a more comprehensive basis. The former can further serve as an experimental method to monitor the behavior of PZT stacks.

  18. Fatigue and failure responses of lead zirconate titanate multilayer actuator under unipolar high-field electric cycling

    NASA Astrophysics Data System (ADS)

    Zeng, Fan Wen; Wang, Hong; Lin, Hua-Tay

    2013-07-01

    Lead zirconate titanate (PZT) multilayer actuators with an interdigital electrode design were studied under high electric fields (3 and 6 kV/mm) in a unipolar cycling mode. A 100 Hz sine wave was used in cycling. Five specimens tested under 6 kV/mm failed from 3.8 × 105 to 7 × 105 cycles, whereas three other specimens tested under 3 kV/mm were found to be still functional after 108 cycles. Variations in piezoelectric and dielectric responses of the tested specimens were observed during the fatigue test, depending on the measuring and cycling conditions. Selected fatigued and damaged actuators were characterized using an impedance analyzer or small signal measurement. Furthermore, involved fatigue and failure mechanisms were investigated using scanning acoustic microscope and scanning electron microscope. The extensive cracks and porous regions were revealed across the PZT layers on the cross sections of a failed actuator. The results from this study have demonstrated that the high-field cycling can accelerate the fatigue of PZT stacks as long as the partial discharge is controlled. The small signal measurement can also be integrated into the large signal measurement to characterize the fatigue response of PZT stacks in a more comprehensive basis. The former can further serve as an experimental method to test and monitor the behavior of PZT stacks.

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

    SciTech Connect

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

    2010-05-15

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

  20. Electrophoretic deposition and sintering of thin\\/Thick PZT films

    Microsoft Academic Search

    J. Van Tassel; C. A. Randall

    1999-01-01

    Electrophoretic deposition (EPD) is a simple, rapid, and low cost method for forming dense lead zirconate titanate (PZT) films down to 5?m from particulate precursors. The three main steps of this process are: (1) formation of a charged suspension of the starting PZT powder; (2) deposition of the powder particles on an electrode under the influence of a dc electric

  1. 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 ...

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

    NASA Astrophysics Data System (ADS)

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

    2004-08-01

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

  3. Local origin of macroscopic properties and patterning in Lead zirconate titanate films

    NASA Astrophysics Data System (ADS)

    Bintachitt, Patamas

    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 PZT films, and the strong propensity for development of {001} orientation. The pyrolysis, crystallization steps, and lead excess addition of PbTiO3 buffer layers deposition were investigated. Using a thin PbTiO3 buffer layer and controlled pyrolysis conditions allowed {100} oriented PZT films to be prepared. The PbTiO3 buffer layer can be used over a full wafer to provide orientation. Higher piezoelectric coefficients, e31,f of -14 and -10 C/m2 were achieved for {001} PZT thin films of 1.0 mum and 0.24 mum thickness, respectively using appropriate poling conditions. The local and global domain wall contributions were studied by piezoelectric nonlinearity and dielectric nonlinearity in both {001}-textured PZT films and PZT films with mixed {001} and {111} orientation. It was found that films over the thickness range probed showed Rayleigh-like behavior. 4 mum thick films were nearly uniform in their Rayleigh coefficient, suggesting that any heterogeneities in the response developed at lateral length scales below the resolution of the PFM measurement. In contrast, thinner films showed significantly more patchiness in their response, so that fluctuations in behavior developed at a lateral length scale on the order of 0.6 to 2.5 micron. These variations did not appear to be correlated directly with the surface topology. Finally, it is hypothesized that the same population of domain wall contributes to the local and global nonlinearity. Nanoindentation measurements were conducted in an attempt to distinguish 180° and non-180° domain wall motion in these films. Non-180° domain walls can be moved by both electrical and mechanical fields. In contrast, 180° domain walls can be moved by electric fields, but not by uniform stresses. In PZT films with mixed {111} and {001} orientation, some ferroelastic wall motion took place during loading, at stress levels on the order of GPa. The reduced elastic modulus is much higher on the unloading curve. Thus, on unloading, it is believed that there is no contribution from mechanical softening associated with ferroelasticity. The global polarization switching in polycrystalline, {001}-textured films on Si, and {001}-films on SrRuO3/SrTiO3 was studied through first order reversal curves (FORC) in order to assess the Preisach distribution governing the switching behavior. Acquisition of multiple hysteresis loops allows polarization switching parameters including nucleation biases, coercive biases, and the amount of switchable response to be mapped in real space. SS-PFM was studied on both bare PZT film surfaces and in capacitor structures (metal/PZT film/metal). The capacitor structure shows the evolution of correlated switching of 102 - 10 3 grain clusters with well-defined imprint and nucleation biases. A transition from a regime where the domain wall motion is over a short range to the formation of clusters to complete switching is observed. The switchable polarization as a function of bias window allows the voltage dependence and spatial distribution of regions with reversible and irreversible wall motions to be mapped. The final chapter of experimental work describes the patterning of PZT films for MEMS. The ability to dry etch large depths of ferroelectric materials such as lead zirconate titanate is important in both microelectromechanical systems and in high frequency medical ultrasound transducers. Dense Pb(Zr 0.52Ti0.48)O3 films (?1 mum) were used to study the etching characteristics. The variation of the etch rate with gas flow rate, source power, substrate holder power, and operation pressure and the uniformity of etching were investigated. The maximum etch rate achieved was 0.31 mum/min. The electric

  4. 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

  5. Comparison of lead zirconate titanate thin films for microelectromechanical energy harvester with interdigitated and parallel plate electrodes.

    PubMed

    Chidambaram, Nachiappan; Mazzalai, Andrea; Balma, Davide; Muralt, Paul

    2013-08-01

    Lead zirconate titanate (PZT) thin films on insulator- buffered silicon substrates with interdigitated electrodes (IDEs) have the potential to harvest more energy than parallel plate electrode (PPE) structures because the former exploit the longitudinal piezoelectric effect, which is about twice as high as the transverse piezoelectric effect used by PPE structures. In this work, both options are compared with respect to dielectric, ferroelectric, and piezoelectric properties, leakage currents, and figure of merit (FOM) for energy harvesting. The test samples were silicon beams with {100} PZT thin films in the case of the PPE geometry, and random PZT thin films for the IDE geometry. Both films were obtained by an identical sol-gel route. Almost the same dielectric constants were derived when the conformal mapping method was applied for the IDE capacitor to correct for the IDE geometry. The dielectric loss was smaller in the IDE case. The ferroelectric loops showed a higher saturation polarization, a higher coercive field, and less back-switching for the IDE case. The leakage current density of the IDE structure was measured to be about 4 orders of magnitude lower than that of the PPE structure. The best FOM of the IDE structures was 20% superior to that of the PPE structures while also having a voltage response that was ten times higher (12.9 mV/? strain). PMID:25004526

  6. Low frequency and microwave magnetoelectric effects in thick film heterostructures of lithium zinc ferrite and lead zirconate titanate

    NASA Astrophysics Data System (ADS)

    Srinivasan, G.; Hayes, R.; Bichurin, M. I.

    2003-11-01

    Magnetoelectric (ME) coupling at low frequencies and at x-band have been investigated in layered samples containing zinc substituted lithium ferrite and lead zirconate titanate (PZT). Multilayers of Li 0.5- x/2 Zn xFe 2.5- x/2 O 4 (LZFO) ( x=0-0.4) and PZT were prepared by lamination and sintering of thick films. At low frequencies (10-1000 Hz), the ME voltage coefficient for transverse fields is higher than for longitudinal fields. With Zn substitution in the ferrite, transverse coupling increases to a maximum for x=0.3 and then decreases for higher x. Analysis based on our model for a bilayer implies an efficient magneto-mechanical coupling with Zn substitution, resulting in strong ME interactions. Microwave ME coupling is studied through measurements of shift in the ferromagnetic resonance field due to an applied electric field. Estimated ME constants from such data are in agreement with our model for a ferrite-PZT bilayer.

  7. Structural development in the early stages of annealing of sol-gel prepared lead zirconate titanate thin films

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Zhang, Q.; Whatmore, R. W.

    1999-08-01

    Lead zirconate titanate (PZT) thin films on platinized silicon were fabricated and their structural development upon annealing was characterized by x-ray diffraction and transmission electron microscopy (TEM). The amount of a transient intermetallic phase Pt3Pb was found initially to increase with annealing time and to decay after reaching a maximum. The kinetic process of growth and decay was simulated by using the Avrami equation. The Avrami coefficient n and growth rate constant k were determined by comparing the experimental results and the simulated curves, from which activation energies of 40 and 145 kJ/mol were obtained for the growth and decay of the intermetallic Pt3Pb phase, respectively. The perovskite PZT was found by using TEM to nucleate epitaxially on top of the Pt3Pb phase. Evidence is presented that the Pt3Pb phase plays a major role in determining the crystallite's orientation at the nucleation stage of the perovskite PZT. This depends strongly on the annealing temperature and the orientation changes little during the following growth process.

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

    NASA Astrophysics Data System (ADS)

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

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  10. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  12. Neutron irradiation effects on domain wall mobility and reversibility in lead zirconate titanate thin films

    NASA Astrophysics Data System (ADS)

    Graham, Joseph T.; Brennecka, Geoff L.; Ferreira, Paulo; Small, Leo; Duquette, David; Apblett, Christopher; Landsberger, Sheldon; Ihlefeld, Jon F.

    2013-03-01

    The effects of neutron-induced damage on the ferroelectric properties of thin film lead zirconate titanate (PZT) were investigated. Two sets of PbZr0.52Ti0.48O3 films of varying initial quality were irradiated in a research nuclear reactor up to a maximum 1 MeV equivalent neutron fluence of (5.16 ± 0.03) × 1015 cm-2. Changes in domain wall mobility and reversibility were characterized by polarization-electric field measurements, Rayleigh analysis, and analysis of first order reversal curves (FORC). With increasing fluence, extrinsic contributions to the small-signal permittivity diminished. Additionally, redistribution of irreversible hysterons towards higher coercive fields was observed accompanied by the formation of a secondary hysteron peak following exposure to high fluence levels. The changes are attributed to the radiation-induced formation of defect dipoles and other charged defects, which serve as effective domain wall pinning sites. Differences in damage accumulation rates with initial film quality were observed between the film sets suggesting a dominance of pre-irradiation microstructure on changes in macroscopic switching behavior.

  13. Effects of Pb5Ge3O11 on pyroelectric lead–zirconate–titanate thick films deposited on silicon substrate by electrophoresis deposition

    NASA Astrophysics Data System (ADS)

    Gui Wu, Chuan; Peng, Qiang Xiang; Sun, Xiang Yu; Meng, Jia; Yao, Shuai; Luo, Wen Bo; Li Zhang, Wan

    2015-04-01

    The effects of Pb5Ge3O11 (PGO) sintering additive on the sintering temperature (Ts) and pyroelectric properties of 1 × 1 mm2 lead–zirconate–titanate (PZT) thick films on Pt/Ti/SiO2/Si substrates were studied. The pattern of PGO-added PZT thick films were formed directly by electrophoresis deposition (EPD). The PGO percentage and Ts were optimized at the range from 0 to 9 wt % and 700 to 900 °C, respectively. The energy dispersive spectrometer (EDS) results showed that the diffusion between Si and PZT were weaken gradually as the Ts decreased. The sintered PZT films sintered at 800 °C with 3 wt % PGO exhibited room-temperature pyroelectric coefficient (Pc) of 1.73 × 10?8 C/(cm2·K), figure of merit for detectivity (FD) of 1.9 × 10?5 Pa?0.5, permittivity of 330 and dielectric loss of 1.5% (1 kHz), respectively. These results demonstrate that the directly patterned PGO-added PZT thick films fabricated by EPD show potential application in MEMS detectors.

  14. Ion Irradiation Damage in Zirconate and Titanate Ceramics for Pu Disposition

    SciTech Connect

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

    2004-07-01

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

  15. Preparation and electrical properties of fine-scale 1-3 lead zirconic titanate/epoxy composite thick films for high-frequency ultrasonic transducers

    NASA Astrophysics Data System (ADS)

    Zhen, Yuhua; Li, Jing-Feng

    2008-04-01

    1-3 connectivity lead zirconic titanate (PZT)/epoxy composite thick films containing fine-scale and high aspect ratio PZT pillars (40?m sectional width, 40?m spacing, and 5.5 aspect ratio) were obtained by a modified dice and fill method. The composite thick film works at a high frequency >7MHz with a clear and uncoupled thickness mode, together with a relatively high electromechanical coupling coefficient (kt=56.4%), low acoustic impedance (Z =7.8 Mrayls), and low mechanical Qm (3.3). High piezoelectric coefficient (d33=332pCN-1) along with reduced dielectric constant (?r=105) endowed the composite films an enhanced piezoelectric voltage coefficient g33 value of 357×10-3m2/C, which is required to increase the receiving voltage sensitivity. The present piezocomposite thick film with microscale ordered structure is promising for high-frequency ultrasonic transducers.

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

    NASA Astrophysics Data System (ADS)

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

    2010-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2001-01-01

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

  18. Electrical Properties and Microstructure of Low-Temperature-Crystallized Lead Zirconate Titanate Thin Films Prepared by 2.45 GHz Microwave Irradiation

    NASA Astrophysics Data System (ADS)

    Wang, Zhan Jie; Otsuka, Yuka; Cao, Zhiping; Kokawa, Hiroyuki

    2009-09-01

    Lead zirconate titanate (PZT) thin films were coated on Pt/Ti/SiO2/Si substrates by a sol-gel method and then crystallized at 490 °C using the magnetic field of 2.45 GHz microwave irradiation. The crystalline phases and microstructures as well as the electrical properties of the PZT thin films were investigated. X-ray diffraction analysis indicated that the films were crystallized well into the perovskite phase. Scanning electron microscopy showed that the PZT films had a typical rosette structure, which consisted of large round grains on a matrix of fine grains. A transmission electron microscopy (TEM) study revealed that the fine grains were also mainly crystallized into the perovskite phase. The average remanent polarization and coercive field of the PZT films were approximately 21 ?C/cm2 and 92 kV/cm, respectively, whereas the dielectric constant and loss value measured at 1 kHz were approximately 510 and 0.07, respectively.

  19. Electrical Properties and Microstructure of Low-Temperature-Crystallized Lead Zirconate Titanate Thin Films Prepared by 2.45 GHz Microwave Irradiation

    NASA Astrophysics Data System (ADS)

    Jie Wang, Zhan; Otsuka, Yuka; Cao, Zhiping; Kokawa, Hiroyuki

    2009-09-01

    Lead zirconate titanate (PZT) thin films were coated on Pt/Ti/SiO2/Si substrates by a sol-gel method and then crystallized at 490 °C using the magnetic field of 2.45 GHz microwave irradiation. The crystalline phases and microstructures as well as the electrical properties of the PZT thin films were investigated. X-ray diffraction analysis indicated that the films were crystallized well into the perovskite phase. Scanning electron microscopy showed that the PZT films had a typical rosette structure, which consisted of large round grains on a matrix of fine grains. A transmission electron microscopy (TEM) study revealed that the fine grains were also mainly crystallized into the perovskite phase. The average remanent polarization and coercive field of the PZT films were approximately 21 µC/cm2 and 92 kV/cm, respectively, whereas the dielectric constant and loss value measured at 1 kHz were approximately 510 and 0.07, respectively.

  20. Seeding effect on the fatigue behaviour of PZT thin films

    Microsoft Academic Search

    Aiying Wu; P. M. Vilarinho; A. L. Kholkin; I. M. Salvado Miranda; J. L. Baptista

    2001-01-01

    Lead zirconate titanate films (PZT) of the morphotropic phase boundary composition were prepared using a diol-based sol-gel route modified by introducing 1–5 mol% PZT nano-seeds (with the same composition as the films). Thin films derived from unseeded and seeded precursors were fabricated on platinised silicon substrates (Pt\\/Ti\\/SiO2\\/Si). The effects of the concentration of seeds on the hysteresis behaviour and fatigue

  1. PZT piezoelectric films on glass for Gen-X imaging

    Microsoft Academic Search

    Rudeger H. T. Wilke; Susan Trolier-McKinstry; Paul B. Reid; Daniel A. Schwartz

    2010-01-01

    The proposed adaptive optics system for the Gen-X telescope uses piezoelectric lead zirconate titanate (PZT) films deposited on flexible glass substrates. The low softening transition of the glass substrates imposes several processing challenges that require the development of new approaches to deposit high quality PZT thin films. Synthesis and optimization of chemical solution deposited 1 mum thick films of PbZr0.52Ti0.48O3

  2. Evaluation of antibacterial properties of Barium Zirconate Titanate (BZT) nanoparticle.

    PubMed

    Mohseni, Simin; Aghayan, Mahdi; Ghorani-Azam, Adel; Behdani, Mohammad; Asoodeh, Ahmad

    2014-01-01

    So far, the antibacterial activity of some organic and inorganic compounds has been studied. Barium zirconate titanate [Ba(ZrxTi1-x)O3] (x = 0.05) nanoparticle is an example of inorganic materials. In vitro studies have provided evidence for the antibacterial activity of this nanoparticle. In the current study, the nano-powder was synthesized by sol-gel method. X-ray diffraction showed that the powder was single-phase and had a perovskite structure at the calcination temperature of 1000 °C. Antibacterial activity of the desired nanoparticle was assessed on two gram-positive (Staphylococcus aureus PTCC1431 and Micrococcus luteus PTCC1625) and two gram-negative (Escherichia coli HP101BA 7601c and clinically isolated Klebsiella pneumoniae) bacteria according to Radial Diffusion Assay (RDA). The results showed that the antibacterial activity of BZT nano-powder on both gram-positive and gram-negative bacteria was acceptable. The minimum inhibitory concentration of this nano-powder was determined. The results showed that MIC values for E. coli, K. pneumoniae, M. luteus and S. aureus were about 2.3 ?g/mL, 7.3 ?g/mL, 3 ?g/mL and 12 ?g/mL, respectively. Minimum bactericidal concentration (MBC) was also evaluated and showed that the growth of E. coli, K. pneumoniae, M. luteus and S. aureus could be decreased at 2.3, 14, 3 and 18 ?g/mL of BZT. Average log reduction in viable bacteria count in time-kill assay ranged between 6 Log10 cfu/mL to zero after 24 h of incubation with BZT nanoparticle. PMID:25763046

  3. Evaluation of antibacterial properties of Barium Zirconate Titanate (BZT) nanoparticle

    PubMed Central

    Mohseni, Simin; Aghayan, Mahdi; Ghorani-Azam, Adel; Behdani, Mohammad; Asoodeh, Ahmad

    2014-01-01

    So far, the antibacterial activity of some organic and inorganic compounds has been studied. Barium zirconate titanate [Ba(ZrxTi1-x)O3] (x = 0.05) nanoparticle is an example of inorganic materials. In vitro studies have provided evidence for the antibacterial activity of this nanoparticle. In the current study, the nano-powder was synthesized by sol-gel method. X-ray diffraction showed that the powder was single-phase and had a perovskite structure at the calcination temperature of 1000 °C. Antibacterial activity of the desired nanoparticle was assessed on two gram-positive (Staphylococcus aureus PTCC1431 and Micrococcus luteus PTCC1625) and two gram-negative (Escherichia coli HP101BA 7601c and clinically isolated Klebsiella pneumoniae) bacteria according to Radial Diffusion Assay (RDA). The results showed that the antibacterial activity of BZT nano-powder on both gram-positive and gram-negative bacteria was acceptable. The minimum inhibitory concentration of this nano-powder was determined. The results showed that MIC values for E. coli, K. pneumoniae, M. luteus and S. aureus were about 2.3 ?g/mL, 7.3 ?g/mL, 3 ?g/mL and 12 ?g/mL, respectively. Minimum bactericidal concentration (MBC) was also evaluated and showed that the growth of E. coli, K. pneumoniae, M. luteus and S. aureus could be decreased at 2.3, 14, 3 and 18 ?g/mL of BZT. Average log reduction in viable bacteria count in time-kill assay ranged between 6 Log10 cfu/mL to zero after 24 h of incubation with BZT nanoparticle. PMID:25763046

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

  5. Synthesis and mechanism research of an ethylene glycol-based sol-gel method for preparing PZT nanopowders

    Microsoft Academic Search

    Zhang De-Qing; Wang Shao-Jun; Sun Hong-Shan; Wang Xiu-Li; Cao Mao-Sheng

    2007-01-01

    Lead zirconate titanate nanopowders Pb(Zr0.52Ti0.48)O3 (PZT) were prepared by modified sol-gel process in ethylene glycol system with zirconium nitrate as the zirconium source.\\u000a The research showed that it was critical to add lead acetate after the reaction of zirconium nitrate and tetrabutyl titanate\\u000a in ethylene glycol system for preparing PZT of exact titanium content. The reaction mechanisms of the sol

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

    Microsoft Academic Search

    Masao Takahashi

    1970-01-01

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

  7. Stereolithography of lead zirconate titanate ceramics for MEMS applications

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

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

  8. Phase Formation in PZT Phosphorus-Doped Ceramics

    SciTech Connect

    Celi, L. A. [Departamento de Fisica, Escuela Politecnica Nacional, Quito (Ecuador); Caballero, A. C.; Villegas, M.; Moure, C.; Fernandez, J. F. [Departamento de Electroceramica, Instituto de Ceramica y Vidrio, Madrid (Spain); Eiras, J. A. [Universidad Federal de Sao Carlos, Departamento de Fisica, Grupo de Ceramicas, Sao Paulo (Brazil)

    2009-04-19

    The surface modification of lead zirconate titanate (PZT) ceramics with phosphate ester leaves a phosphorus residue absorbed onto the particle surface. During the sintering processes, this surface layer reacts with the PZT to form lead-rich compounds, such as Pb{sub 3}(PO{sub 4}){sub 2} and Pb{sub 4}(P{sub 2}O{sub 9}). The formation of such a compounds may be the responsible for the grain growth inhibition observed in PZT-modified ceramics, as well as the lead loss reduction.

  9. Dielectric Properties of PVDF/PZT

    SciTech Connect

    Zak, A. Khorsand; Chen, Gan Wee; Majid, W. H. Abd. [Low dimensional material research center, Department of physics, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia)

    2011-03-30

    Poly(vinylidene fluoride)/ lead zirconate titanate nanocomposite (PVDF/PZT-NPs) were successfully prepared by mixing fine Pb(Zr{sub 0.52}, Ti{sub 0.48})O{sub 3} nanoparticles (PZT-NPs) into a PVDF solution under ultrasonication. The mixture was spin coated onto glass substrate and then annealed at 80 deg. C. X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used to characterize the structure and properties of the obtained thin-film nanocomposites. The nanocomposites exhibited good dielectric stability over a wide frequency range.

  10. Evolution of the fractal surface of amorphous lead zirconate-titanate films during crystallization

    Microsoft Academic Search

    V. Ya. Shur; S. A. Negashev; A. L. Subbotin; D. V. Pelegov; E. A. Borisova; E. B. Blankova; S. Trolier-McKinstry

    1999-01-01

    The recrystallization kinetics of amorphous lead zirconate-titanate films prepared by sol-gel technology are investigated\\u000a experimentally using elastic scattering of light. Sequences of elastic dependences of the scattered light intensity are recorded\\u000a directly during thermal annealing. The evolution of the morphology of the film surface during annealing is described in terms\\u000a of the variation of their fractal dimensionalities D\\u000a s. The

  11. Dynamic magnetoelectric effects in bulk and layered composites of cobalt zinc ferrite and lead zirconate titanate

    Microsoft Academic Search

    G. Srinivasan; R. Hayes; C. P. DeVreugd; V. M. Laletsin; N. Paddubnaya

    2005-01-01

    Low-frequency magnetoelectric (ME) coupling is investigated in bulk samples and multilayers of cobalt zinc ferrite, Co 1-xZn xFe 2O 4 (x=0–0.6), and lead zirconate titanate. In bulk samples, the transverse and longitudinal couplings are weak and of equal magnitude. A substantial strengthening of ME interactions is evident in layered structures, with the ME voltage coefficient a factor of 10–30 higher

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

  13. Integration of PLZT and BST family oxides with GaN[Lead Lanthanum Zirconate Titanate, Barium Strontium Titanate

    SciTech Connect

    Osinsky, A.V.; Fuflyigin, V.N.; Wang, F.; Vakhutinsky, P.I.

    2000-07-01

    Recent advances in the processing of complex-oxide materials has allowed the authors to monolithically grow ferroelectrics of lead lanthanum zirconate titanate (PLZT) and barium strontium titanate (BST) systems on a GaN/sapphire structure. High quality films of PLZT and BST were grown on GaN/c-Al{sub 2}O{sub 3} in a thickness range of 0.3--5 {micro}m by a sol-gel technique. Field-induced birefringence, as large as 0.02, was measured from a PLZT layer grown on a buffered GaN/sapphire structure. UV illumination was found to result in more symmetrical electrooptic hysteresis loop. BST films on GaN demonstrated a low frequency dielectric constant of up to 800 with leakage current density as low as 5.5 {center_dot} 10{sup {minus}8} A/cm{sup 2}.

  14. A New Impedance Measurement System for PZT-Based Structural Health Monitoring

    Microsoft Academic Search

    Fabricio GuimarÃes Baptista; José Viterbo Filho

    2009-01-01

    Recent research has shown that electromechanical (E\\/M) impedance-based techniques are an efficient strategy for damage sensing in the context of structural health monitoring (SHM). The basic principle is to excite the lead zirconate titanate (PZT) sensors attached to the structure and to measure the corresponding electrical impedance. A variation in the electrical impedance indicates a variation in the mechanical impedance

  15. Piezoelectric Composite Materials for Ultrasonic Transducer Applications. Part I: Resonant Modes of Vibration of PZT Rod-Polymer Composites

    Microsoft Academic Search

    T. R. Gururaja; WALTER A. SCHULZE; LESLIE E. CROSS; ROBERT E. NEWNHAM; BERTRAM A. AULD; YUZHONG J. WANG

    1985-01-01

    Abstmcr-The objective of the present work was to gain a deeper mensions of the transducer are much smaller than the understanding of the behavior of lead zirconate titanate (PZT) polymer composites for applications such as ultrasonic medical diagnosis in the megahertz frequency range. These composites were originally developed for low-frequency hydrophone applications. The PZT rod-polymer composites have been prepared with

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

    NASA Astrophysics Data System (ADS)

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

    2011-04-01

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

  17. Compact piezoelectric micromotor with a single bulk lead zirconate titanate stator

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  18. MEMS power generator with transverse mode thin film PZT

    Microsoft Academic Search

    Y. B. Jeon; R. Sood; J.-h. Jeong; S.-G. Kim

    2005-01-01

    A thin film lead zirconate titanate, Pb(Zr,Ti)O3 (PZT), MEMS power generating device is developed. It is designed to resonate at specific frequencies from an external vibrational energy source, thereby creating electrical energy via the piezoelectric effect. Our cantilever device is designed to have a flat structure with a proof mass added to the end. The Pt\\/Ti top electrode is patterned

  19. Low Temperature Sintering of PZT

    NASA Astrophysics Data System (ADS)

    Medesi, A.; Greiner, T.; Benkler, M.; Megnin, C.; Hanemann, T.

    2014-11-01

    This paper describes the fabrication and characterization of lead zirconate titanate (PZT) films fired in a liquid-phase sintering process at 900 °C in air. In detail the manufacturing of piezoelectric multilayers with internal pure silver (Tm = 961 °C) electrodes are reported. The feasibility of ten sintering aids in two different volume fractions was investigated for a commercial hard PZT powder (PIC 181, PI Ceramics) with respect to density, microstructure, mechanical behaviour, and piezoelectric properties. Li2O, Li2CO3, PbO, MnO2, V2O5, CuO, Bi2O3, the eutectic mixtures Cu2O·PbO and PbO·WO3 and the ternary system Li2CO3·Bi2O3·CuO (LBCu) have been tested as liquid phase sintering aids. The combination of PZT with LBCu showed the best results. With 5 vol.% LBCu an average relative density of 97% and a characteristic breaking strength of 77 MPa was achieved. Composition of PZT with 2 vol.% LBCu exhibits the highest averaged piezoelectrical charge constant (d33) of 181 pC/N.

  20. Effect of Heating and Cooling on the Piezoelectric Properties of a PZT Sensor for Mercury Dust Monitor

    NASA Astrophysics Data System (ADS)

    Iwai, Takeo; Nakamura, Maki; Ohashi, Hideo; Shibata, Hiromi; Miyachi, Takashi; Takechi, Seiji; Yano, Hajime; Sasaki, Sho; Fujii, Masayuki; Nogami, Ken-Ichi; Grün, Eberhard; Srama, Ralf

    Temperature dependence of piezoelectric response of a Lead Zirconate Titanate (PZT) sensor for Mercury Dust Monitor (MDM) was investigated with an electrostatic accelerator. The temperature dependence was not so substantial between room temperature and 423 K. This fact leads to good sensor performance and a simplified data analysis during the mission.

  1. Temperature effects on the mechanical behaviour of PZT 95/5

    NASA Astrophysics Data System (ADS)

    Khan, A. S.; Balzer, J. E.; Wilgeroth, J. M.; Proud, W. G.

    2014-05-01

    This research is to develop a better understanding of the piezoelectric ceramic lead zirconate titanate (PZT) 95/5 with varying temperatures, porosities and strain rates. Here, unpoled PZT samples of two different porosities were subjected to a range of compression rates, using quasi-static loading equipment, drop-weight towers and Split Hopkinson Pressure Bars (SHPBs). Varying temperatures were achieved using purpose-made environmental chambers. The resulting stress-strain relationships are compared. The samples were square tiles, 7.5 × 7.5 mm and 3 mm thickness. The density of the standard PZT used here was 7.75 g cm-3 (henceforth described as PZT), whilst the density of the higher porosity PZT was 7.38 g cm-3 (henceforth described as PPZT). This research is part of a wider study.

  2. Thickness dependence of D.C. leakage current in lead zirconate-titanate (PZT) memories

    Microsoft Academic Search

    B. M. Melnick; J. F. Scott; C. A. Paz De Araujo; L. D. McMillan

    1992-01-01

    We have measured the voltage (field) dependence, the thickness dependence, and the temperature dependence of d.c. leakage currents in PbZr0.40Ti0.60O3. In agreement with our earlier results [Scott et al., J. Appl. Phys. 70, 382 (1991)], the voltage dependence is given by I(V) = AV + B(V - V0), implying space-charge limited currents. In addition, in the present work we find

  3. Characterization of ferroelectric material properties of multifunctional lead zirconate titanate for energy harvesting sensor nodes

    NASA Astrophysics Data System (ADS)

    Marinkovic, Bozidar; Kaya, Tolga; Koser, Hur

    2011-01-01

    We propose a microsystem integration technique that is ideal for low-cost fabrication of vibration energy harvesting sensor nodes. Our approach exploits diverse uses of sol-gel deposited lead zirconate titanate, effectively combining fabrication of several microsystem components into a single process and significantly reducing manufacturing cost and time. Here, we measure and characterize thin film parameters—such as the piezoelectric coefficient e31 (-4.0 C/m2), the dielectric constant ?r-eff (219 at 3.3 V), and the total switching polarization (2Pr;52 ?C/cm2)—in order to verify this material's potential for energy harvesting, energy storage, and nonvolatile memory applications simultaneously on the same device.

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  5. Pb nanowire formation on Al/lead zirconate titanate surfaces in high-pressure hydrogen

    NASA Astrophysics Data System (ADS)

    Alvine, Kyle J.; Shutthanandan, Vaithiyalingam; Arey, Bruce W.; Wang, Chongmin; Bennett, Wendy D.; Pitman, Stan G.

    2012-07-01

    Piezoelectric systems are well known to degrade in hydrogen because of various mechanisms including loss of polarization, Pb migration into the electrode, and surface blistering. Understanding damage mechanisms is crucial for potential high-pressure applications such as injectors for hydrogen-fueled vehicles. In this paper, we report on a previously unreported form of high-pressure hydrogen damage resulting from growth of surface Pb nanowires from an Al electrode on lead zirconate titanate. Wires were observed with roughly 80 nm diameter and with length that varied between 5 and 100 ?m. Microscopy to characterize the nanowires and ion-scattering measurements to quantify concurrent Pb surface migration and hydrogen absorption effects are described.

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

    PubMed

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

    2009-05-15

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

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

    PubMed

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

    2011-02-14

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

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

    PubMed

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

    2014-01-01

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

  9. Optical Properties of Lead Lanthanum Zirconate Titanate Amorphous Ferroelectric-Like Thin Films

    NASA Astrophysics Data System (ADS)

    Li, Huiqiu; Zhang, Yueli; Wen, Jinhui; Yang, Shenghong; Mo, Dang; Cheng, Chih-Hsing; Xu, Yuhuan; Mackenzie, J. D.

    2000-03-01

    Lead lanthanum zirconate titanate (PLZT) amorphous thin films, whose composition is 5/50/50, have been prepared by the sol-gel technique. The optical transmission property of the thin film was measured in the wavelength range of 200-820 nm. The ellipsometric spectra of the PLZT thin film on a glass substrate were measured in the wavelength range of 200-670 nm, and their optical constant (refractive index n and extinction coefficient k) spectra have been determined. The dispersion of the refractive index is interpreted in terms of a single electric oscillator at 9.64 eV@. The direct band energy is found to be 3.67 eV.

  10. Optical and Photoelectrochemical Properties of Lead Zirconate Titanate Thin Films Obtained by the Sol-Gel Method

    NASA Astrophysics Data System (ADS)

    Poznyak, S. K.; Kulak, A. I.

    2014-11-01

    We obtained optically transparent n-type semiconductor films of lead zirconate titanate Pb(ZrxTi1-x)O3 by reaction of individual sols of hydrated titanium dioxide and zirconium dioxide with lead ions, followed by heat treatment at 500-800°C. We established that these films, when in contact with an aqueous electrolyte, can generate a photopotential and a photocurrent when exposed to UV radiation (250-400 nm). The average values of the bandgap energy from optical absorption and photocurrent spectroscopy data are slightly dependent on the composition of the lead zirconate titanate solid solution (they increase by 0.07-0.12 eV on going from Pb(Zr0.2Ti0.8)O3 to Pb(Zr0.52Ti0.48)O3), which may be connected with features of the band structure in these materials.

  11. A patterning technique of lead zirconate titanate thin film by ultraviolet-light

    Microsoft Academic Search

    Chia-Che Wu; Chueh-Tang Chang

    2012-01-01

    The patterning technique of PZT thin film is an essential process in device fabrication processes for application in microsensors and microactuators. Chemical etching and physical etching processes are two of the most commonly used techniques to pattern PZT thin film. However, the difference in etching yields of Pb, Zr, and Ti leads to undesired residues on PZT films in chemical

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

    Microsoft Academic Search

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

    2005-01-01

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

  13. Effect of crystallinity on thermal transport in textured lead zirconate titanate thin films.

    PubMed

    Varghese, Ronnie; Harikrishna, Hari; Huxtable, Scott T; Reynolds, W T; Priya, Shashank

    2014-05-14

    We demonstrate the use of the time domain thermoreflectance (TDTR) technique towards understanding thermal transport in textured Pb(Zr,Ti)O3 (PZT) thin films grown by a sol-gel process on platinized silicon substrates. PZT films were grown with preferred crystallographic orientations of (100), (110), and (111). Grain orientation was controlled by manipulating the heterogeneous nucleation and growth characteristics at the interface between the film and the underlying Pt layer on the substrate. TDTR was used to measure both the PZT film thermal conductivity and the interface thermal conductance between the PZT and Pt as well as that between the PZT and an Al thermoreflectance layer evaporated on the PZT surface. We find a hierarchical dependence of thermal conductivity on the crystallographic orientation of the PZT films and observed differences in the thermal conductances between the Al-PZT and PZT-Pt interfaces for a varying degree of preferred orientations (100), (110), and (111). Thus, the technique based upon nanoscale thermal measurements can be used to delineate PZT samples with different crystallographic orientations. The thermal conductivities of the PZT films with different crystal orientations were in the range of 1.45-1.80 W m(-1) K(-1). The interface thermal conductance between the PZT and Pt layer was in the range of 30-65 MW m(-2) K(-1), while the conductance between the Al layer and PZT was in the range of 90-120 MW m(-2) K(-1). These interfacial conductances exhibit significant correlations to the texture of the PZT film and elemental concentration and densities at those interfaces. PMID:24689852

  14. Phase transformation kinetics induced in thin sol-gel PZT films under thermal annealing

    Microsoft Academic Search

    V. Ya. Shur; E. B. Blankova; A. L. Subbotin; E. A. Borisova; A. V. Barannikov

    2001-01-01

    The surface morphology evolution and phase transformation kinetics in thin lead zirconate-titanate (PZT) sol-gel films during\\u000a rapid thermal annealing were studied by in situ measurement of scattered light intensity and by recording successive instantaneous optical microscope images. We also studied\\u000a the variation of the texture perfection, the fraction of the growing phase, and the angular dependence of the scattered intensity

  15. Indications of room-temperature superconductivity at a metal-PZT interface

    Microsoft Academic Search

    Dhruba Dasgupta; Raja Rammohunpur

    2010-01-01

    We report the observation of an exceptionally large room-temperature electrical conductivity in silver and aluminum layers deposited on a lead zirconate titanate (PZT) substrate. The surface resistance of the silver-coated samples also shows a sharp change near 313 K. The results are strongly suggestive of a superconductive interfacial layer, and have been interpreted in the framework of Bose-Einstein condensation of

  16. Elasticity Imaging of Ferroelectric Domain Structure in PZT by Ultrasonic Atomic Force Microscopy

    SciTech Connect

    Tsuji, T. [National Institute of Advanced Industrial Science and Technology, Tsukuba, 3058564 (Japan); Tohoku university, Sendai, Japan 9808579 (Japan); Ogiso, H. [National Institute of Advanced Industrial Science and Technology, Tsukuba, 3058564 (Japan); Fukuda, K.; Yamanaka, K. [Tohoku university, Sendai, 9808579 (Japan)

    2004-02-26

    UAFM was applied to the observation of the domain structure in lead zirconate titanate (PZT). It imaged the change of elasticity due to grain and domain boundary (DB). For the quantitative evaluation of the contact stiffness, the lateral contact stiffness was taken into account. The stiffness of DB was 10% lower than that within the domain and the width of the DB was about 30 nm. The implication of this work is the understanding of the fatigue mechanism in a PZT memory and the high resolution imaging for a high-density memory.

  17. New Fabrication of High-Frequency (100-MHz) Ultrasound PZT Film Kerfless Linear Array

    PubMed Central

    Zhu, Benpeng; Chan, Ngai Yui; Dai, Jiyan; Shung, K. Kirk; Takeuchi, Shinichi; Zhou, Qifa

    2013-01-01

    The paper describes the design, fabrication, and measurements of a high-frequency ultrasound kerfless linear array prepared from hydrothermal lead zirconate titanate (PZT) thick film. The 15-µm hydrothermal PZT thick film with an area of 1 × 1 cm, obtained through a self-separation process from Ti substrate, was used to fabricate a 32-element 100-MHz kerfless linear array with photolithography. The bandwidth at ?6 dB without matching layer, insertion loss around center frequency, and crosstalk between adjacent elements were measured to be 39%, ?30 dB, and ?15 dB, respectively. PMID:23549547

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

    PubMed

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

    2010-01-01

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

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

    PubMed Central

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

    2010-01-01

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

  20. Oxalate co-precipitation synthesis of calcium zirconate and calcium titanate powders.

    SciTech Connect

    Hernandez-Sanchez, Bernadette A.; Tuttle, Bruce Andrew

    2009-06-01

    Fine powders of calcium zirconate (CaZrO{sub 3}, CZ) and calcium titanate (CaTiO{sub 3}, CT) were synthesized using a nonaqueous oxalate co-precipitation route from Ca(NO{sub 3}){sub 2}{center_dot}4 H{sub 2}O and group(IV) n-butoxides (Ti(OBu{sup n}){sub 4} or Zr(OBu{sup n}){sub 4}). Several reaction conditions and batch sizes (2-35 g) were explored to determine their influence on final particle size, morphology, and phase. Characterization of the as-prepared oxalate precursors, oven dried oxalate precursors (60-90 C), and calcined powders (635-900 C) were analyzed with TGA/DTA, XRD, TEM, and SEM. Densification and sintering studies on pressed CZ pellets at 1375 and 1400 C were also performed. Through the developed oxalate co-precipitation route, densification temperatures for CZ were lowered by 125 C from the 1500 C firing temperature required for conventional mixed oxide powders. Low field electrical tests of the CZ pellets indicated excellent dielectric properties with dielectric constants of {approx}30 and a dissipation factor of 0.0004 were measured at 1 kHz.

  1. Study of samarium modified lead zirconate titanate and nickel zinc ferrite composite system

    NASA Astrophysics Data System (ADS)

    Rani, Rekha; Juneja, J. K.; Singh, Sangeeta; Raina, K. K.; Prakash, Chandra

    2015-03-01

    In the present work, composites of samarium substituted lead zirconate titanate and nickel zinc ferrite with compositional formula 0.95Pb1-3x/2 SmxZr0.65Ti0.35O3-0.05Ni0.8Zn0.2Fe2O4 (x=0, 0.01, 0.02 and 0.03) were prepared by the conventional solid state route. X-ray diffraction analysis was carried out to confirm the coexistence of individual phases. Microstructural study was done by using scanning electron microscope. Dielectric constant and loss were studied as a function of temperature and frequency. To study ferroelectric and magnetic properties of the composite samples, corresponding P-E and M-H hysteresis loops were recorded. Change in magnetic properties of electrically poled composite sample (x=0.02) was studied to confirm the magnetoelectric (ME) coupling. ME coefficient (dE/dH) of the samples (x=0 and 0.02) was measured as a function of DC magnetic field.

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

    SciTech Connect

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

    1999-03-01

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

  3. Improved ferroelectric and pyroelectric properties in Mn-doped lead zirconate titanate thin films

    NASA Astrophysics Data System (ADS)

    Zhang, Q.; Whatmore, R. W.

    2003-10-01

    We have investigated the effects of Mn doping on the ferroelectric and pyroelectric properties of Pb(Zr0.3Ti0.7)O3 (PZT) thin films on substrates Pt/Ti/SiO2/Si. The Mn-doped (1 mol %) PZT (PMZT) showed almost no hysteretic fatigue up to 1010 switching bipolar pulse cycles, coupled with excellent retention properties. We present evidence that while a low permittivity interfacial layer forms between the Pt electrode and PZT films, this does not occur in PMZT. We propose that Mn dopants are able to reduce oxygen vacancy mobility in PZT films and Mn2+ ions consume the oxygen vacancies generated during repeated switching, forming Mn4+ ions. These mechanisms are probably responsible for their low observed fatigue characteristics. Mn doping brings additional benefits to the electrical properties of PZT films. The relevant pyroelectric coefficients (p) of a 700 nm thick film are 3.52×10-4 C m-2 K-1 and detectivity figures of merit FD=3.85×10-5 Pa-0.5 at 33 Hz for Mn-doped PZT, compared with p=2.11×10-4 C m-2 K-1 and FD=1.07×10-5 Pa-0.5 for the undoped PZT films. This means that the Mn-doped PZT thin films are excellent candidates as device materials for both memory and pyroelectric applications.

  4. Directed colloidal assembly and characterization of PZT-polymer composites

    NASA Astrophysics Data System (ADS)

    Smay, James Earl

    Lead zirconate titanate (PZT)-based layers and 3-D structures were directly assembled using two colloidal routes: (1) tape casting and (2) a layer-by-layer robotic deposition technique, known as robocasting. First, concentrated (?solids > 0.45) suspensions of PZT-5H and a latex emulsion were tape cast with the aid of viscosifier and surfactant additions. Drying stress evolved to a maximum at ? PZT ˜ 0.49, followed by a reduction and a secondary stress rise attributed to latex coalescence. Dielectric and piezoelectric properties of sintered PZT multilayer laminates exhibited good agreement with those for isostatically pressed and sintered samples. Concentrated, weakly gelled suspensions of PZT 95/5 and poly(ethylene) (PE) latices, a fugitive species, were developed as inks for the robotic deposition of monolithic and tri-layered composite structures. Monoliths, with densities of 93.6% and 96.1%, and composites with a 96.1% dense layer between 93.6% regions were fabricated. The structures displayed equivalent electrical properties to cold isostatically pressed parts. The composites withstood repeated saturation polarization switching as well as a 500 MPa hydrostatic pressure-induced poled ferroelectric (FE) to antiferroelectric (AFE) phase transformation. Concentrated (?PZT = 0.47) PZT-5H gels were developed as inks for the robotic deposition of 3-D, mesoscale periodic structures with self-supporting features such as lattices of rod-like elements and v-shaped test structures. The gels exhibited pH dependent viscoelastic properties and Hershel-Bulkley flow behavior. The deflection of as-deposited spanning elements was measured using laser profilometry. Flow modeling and shape evolution data indicated a core-shell architecture as the ink exited the deposition nozzle, which simultaneously provided strength to form spanning elements and good bonding between layers. The core grew rapidly (˜1s) due to the quick recovery of gel structure in these inks. 3-X type PZT-polymer composites consisting of PZT lattices in a polymer matrix (3-3), a lattice/polymer matrix with PZT faceplates (3-2), or a lattice/polymer matrix with faceplates and encircled by a solid PZT ring (3-1) were formed and their piezoelectric properties were characterized. The PZT:polymer ratio was controlled by the lattice spacing in these thin composites (˜1 mm). Lattice rod intersections formed high permittivity, low compliance PZT pillars that concentrated stress and electric flux, leading to improved hydrostatic figures of merit.

  5. Microstrain in tetragonal lead-zirconate-titanate: The effect of pressure on the ionic displacements

    SciTech Connect

    Frantti, J., E-mail: Johannes.Frantti@fre.fi; Fujioka, Y. [Finnish Research and Engineering, Jaalaranta 9 B 42, 00180 Helsinki (Finland); Zhang, J.; Zhu, J.; Vogel, S. C.; Zhao, Y. [Los Alamos Neutron Science Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-08-15

    Piezoelectric materials respond to external stimuli by adjusting atomic positions. In solid-solutions, the changes occurring in atomic scale are very complex since the short- and long-range order are different. Standard methods used in diffraction data analysis fail to model the short-range order accurately. Pressure-induced cation displacements in ferroelectric Pb(Zr{sub 0.45}Ti{sub 0.55})O{sub 3} perovskite oxide are modeled by starting from a short-range order. We show that the model gives the average structure correctly and properly describes the local structure. The origin of the microstrain in lead zirconate titanate is the spatially varying Zr and Ti concentration and atomic distances, which is taken into account in the simulation. High-pressure neutron powder diffraction and simulation techniques are applied for the determination of atomic positions and bond-valences as a function of pressure. Under hydrostatic pressure, the material loses its piezoelectric properties far before the transition to the cubic phase takes place. The total cation valence +6 is preserved up to 3.31 GPa by compensating the increasing B-cation valence by decreasing Pb-displacement from the high-symmetry position. At 3.31 GPa, Pb-displacement is zero and the material is no more ferroelectric. This is also the pressure at which the Pb-valence is minimized. The average structure is still tetragonal. The model for microstrain predicts that the transition occurs over a finite pressure range: Pb-displacements are spatially varying and follow the distribution of Zr and Ti ions.

  6. Dielectric and Ferroelectric Properties of Lead Lanthanum Zirconate Titanate Thin Films for Capacitive Energy Storage

    NASA Astrophysics Data System (ADS)

    Tong, Sheng

    As the increasing requirement of alternative energy with less pollution influence and higher energy efficient, new energy source and related storage methods are hot topic nowadays. Capacitors that supply high instant power are one of the keys in this application for both economic and functional design aspects. To lower the cost and increases the volumetric efficiency and reliability, relaxor thin films are considered as one of the candidates of the next generation capacitors. The research mainly focuses on dielectric and ferroelectric properties of lead lanthanum zirconate titanate or Pb1-xLax(ZryTi1-y)O3 (PLZT, x/y/1-y) relaxor thin films deposited on silicon (Si) and nickel (Ni) substrates in a range of thickness with different bottom electrodes, e.g. Platinum (Pt) and LaNiO3 (LNO). The final fabricated PLZT film capacitors will show strong potential for the energy storage application. The method adopted is the acetic acid assisted sol-gel deposition for the PLZT thin films. The wet chemical process is cost-effective and easily to scale up for plant/industrial products. We investigated the different bottom electrode/substrate influence in structure, microstructure, phases/defects, and heat-treatment conditions to achieve the optimized PLZT thin films. Issues of basic physical size effects in the PLZT thin films were also investigated, including thickness effects in the dielectric and ferroelectric properties of the films in a wide range of temperatures, the phase transition of the thin-film relaxors, lanthanum content effect, electrode-dielectric junction, misfit strain effect, etc. Based on the results and analysis, optimum PLZT film capacitors can be determined of proper substrate/electrode/dielectric that achieves the desired dielectric properties required for different applications, especially a more cost-effective method to develop volumetrically efficient capacitors with high charge density, energy density, dielectric breakdown strength, energy storage efficiency, and low dielectric loss, leakage current density.

  7. Effect of Excess Lead Addition on Processing of Sol-Gel Derived Lanthanum-Modified Lead Zirconate Titanate Thin Film

    NASA Astrophysics Data System (ADS)

    Hirano, Tomio; Kawai, Hiroki; Suzuki, Hisao; Kaneko, Shoji; Wada, Tatsuya

    1999-09-01

    Sol-gel-derived lanthanum-modified lead zirconate titanate (PLZT) thin films with a La/Zr/Ti ratio of 10/65/35 and a lead lanthanum titanate (PLT) thin seeding layer were successfully deposited on an indium tin oxide (ITO)-coated soda lime glass substrate at 500°C. Effects of excess lead addition of different concentrations in the precursor solution on the electrical properties of the resultant PLZT thin films were investigated. As a result, the relative permittivity increased and the dissipation factor decreased with the increase of excess lead concentration. Excess lead of 30 mol% was indispensable for obtaining PLZT thin film with good ferroelectricity. In addition, the resultant films showed more than 60% transmittance in the visible region.

  8. Thickness dependence of electrical properties of PZT films deposited on metal substrates by laser-assisted aerosol deposition

    Microsoft Academic Search

    So Baba; Hiroki Tsuda; Jun Akedo

    2008-01-01

    Dependence of electrical properties-dielectric, ferroelectric, and piezoelectric properties-on film thickness was studied for lead-zirconate-titanate (PZT) thick films directly deposited onto stainless-steel (SUS) substrates in actuator devices by using a carbon dioxide (CO2), laser-assisted aerosol deposition technique. Optical spectroscopic analysis data and laser irradiation experiments revealed that absorption at a given wavelength by the film increased with increasing film thickness. Dielectric

  9. The mechanism of low temperature sintering PZT ceramics with additives of Li2OBi2O3-CdO

    Microsoft Academic Search

    X. Wang; P. Lu; D. Shen; W. Zue; M. Zhao

    1992-01-01

    The effects of Li2O, Bi2O3, CdO, and V2O5 on sintering temperature and electromechanical properties were investigated for PZT (lead zirconate titanate) ceramics. In order to reduce the sintering temperatures further, complex additives of Li2O-Bi2O3-CdO (LBC) were employed. LBC will melt to form liquid at low temperature and promote the densification of the ceramics. The mass transport process of the solution

  10. Thermally induced modifications of the optic properties of lead zirconate titanate thin films obtained on different substrates by sol-gel synthesis

    SciTech Connect

    D'Elia, Stefano; Castriota, Marco; Scaramuzza, Nicola; Versace, Carlo; Cazzanelli, Enzo; Vena, Carlo; Strangi, Giuseppe; Bartolino, Roberto [Department of Physics, INFM-CNR-LICRYL Laboratory and CEMIF.CAL, University of Calabria, via P. Bucci 33B, Rende, Cosenza I-87036 (Italy); Policicchio, Alfonso; Agostino, Raffaele Giuseppe [Department of Physics, University of Calabria, via P. Bucci 33B, Rende, Cosenza I-87036 (Italy)

    2008-12-15

    Lead zirconium titanate PbZr{sub 0.53}Ti{sub 0.47}O{sub 3} (PZT) thin films have been obtained by sol-gel synthesis, deposited on different substrates [float glass, indium tin oxide (ITO)-coated float glass, and intrinsic silicon wafer], and later subjected to different thermal treatments. The morphologic and the structural properties of both PZT thin films and substrates have been investigated by scanning electron microscope and their composition was determined by energy dispersive x-ray (EDX) analysis. Moreover, variable angle spectroscopic ellipsometry provides relevant information on the electronic and optical properties of the samples. In particular, the optical constant dispersion of PZT deposited on ITO-coated float glasses shows a small absorption resonance in the near IR region, not observed in PZT films deposited on the other substrates, so that such absorption resonance can be explained by interfacial effects between ITO and PZT layers. This hypothesis is also supported by EDX measurements, showing an interdiffusion of lead and indium ions, across the PZT-ITO interface, that can generate a peculiar charge distribution in this region.

  11. Structural, ferroelectric and optical properties of PZT thin films

    NASA Astrophysics Data System (ADS)

    Pandey, S. K.; James, A. R.; Raman, R.; Chatterjee, S. N.; Goyal, Anshu; Prakash, Chandra; Goel, T. C.

    2005-12-01

    We report on the structural, ferroelectric and optical properties of lead zirconate titanate (PZT) thin films (with a molar ratio of Zr:Ti::65:35) deposited by sol-gel technique on ITO-coated corning 7059 glass substrates. A seed layer of PbTiO 3 (0.1 ?m) was coated by sol-gel on the substrates before depositing PZT. A metal/ferroelectric/metal (MFM) structure was used for electrical property measurements, formed by depositing gold electrodes on top of the film. The films were characterized for C- V, I- V, P- E and optical transmission. Relatively low remnant polarization ( P=3.6 ?C/cm2) was observed for the films. Value of optical band gap was found to be 3.4 eV. The results are discussed.

  12. Rapid crystallization of ferroelectric lead zirconate titanate thin films by microwave heating

    NASA Astrophysics Data System (ADS)

    Wang, X. W.; Wang, Z. J.; Zhu, M. W.; Zhang, Y. Q.; Zhang, Z. D.

    2012-04-01

    Pb(Zr0.52Ti0.48)O3 (PZT) thin films were coated onto Pt/Ti/SiO2/Si substrates by a sol-gel method and then crystallized by 2.45 GHz microwave irradiation in the magnetic field. The crystalline phases and microstructures as well as the electrical properties of the PZT films were investigated as a function of the annealing temperature from 550 to 750°C for 60 s. The crystallization behavior of the PZT films annealed at 650°C for different times were also investigated. X-ray diffraction and transmission electron microscopy reveal that the pyrochlore phase is formed initially but that it transforms into the perovskite phase very quickly. The ferroelectric and dielectric properties of the PZT films are correlated to the crystallization behavior. The annealing time to obtain perovskite PZT films with good electrical properties at 650°C is only 60 s, and is much shorter than that in conventional furnace annealing process. The reasons for the reduction of annealing time in the rapid microwave annealing process are also discussed.

  13. Rapid crystallization of ferroelectric lead zirconate titanate thin films by microwave heating

    NASA Astrophysics Data System (ADS)

    Wang, X. W.; Wang, Z. J.; Zhu, M. W.; Zhang, Y. Q.; Zhang, Z. D.

    2011-11-01

    Pb(Zr0.52Ti0.48)O3 (PZT) thin films were coated onto Pt/Ti/SiO2/Si substrates by a sol-gel method and then crystallized by 2.45 GHz microwave irradiation in the magnetic field. The crystalline phases and microstructures as well as the electrical properties of the PZT films were investigated as a function of the annealing temperature from 550 to 750°C for 60 s. The crystallization behavior of the PZT films annealed at 650°C for different times were also investigated. X-ray diffraction and transmission electron microscopy reveal that the pyrochlore phase is formed initially but that it transforms into the perovskite phase very quickly. The ferroelectric and dielectric properties of the PZT films are correlated to the crystallization behavior. The annealing time to obtain perovskite PZT films with good electrical properties at 650°C is only 60 s, and is much shorter than that in conventional furnace annealing process. The reasons for the reduction of annealing time in the rapid microwave annealing process are also discussed.

  14. Temperature Dependent Mechanical Property of PZT Film: An Investigation by Nanoindentation

    PubMed Central

    Li, Yingwei; Feng, Shangming; Wu, Wenping; Li, Faxin

    2015-01-01

    Load-depth curves of an unpoled Lead Zirconate Titanate (PZT) film composite as a function of temperature were measured by nanoindentation technique. Its reduce modulus and hardness were calculated by the typical Oliver-Pharr method. Then the true modulus and hardness of the PZT film were assessed by decoupling the influence of substrate using methods proposed by Zhou et al. and Korsunsky et al., respectively. Results show that the indentation depth and modulus increase, but the hardness decreases at elevated temperature. The increasing of indentation depth and the decreasing of hardness are thought to be caused by the decreasing of the critical stress needed to excite dislocation initiation at high temperature. The increasing of true modulus is attributed to the reducing of recoverable indentation depth induced by back-switched domains. The influence of residual stress on the indentation behavior of PZT film composite was also investigated by measuring its load-depth curves with pre-load strains. PMID:25768957

  15. Mechanical Properties of PZT 52/48 under Shock and Ramp Wave Compression

    NASA Astrophysics Data System (ADS)

    Wise, J. L.; Montgomery, S. T.; Jackson, D. P.; Clark, G. E.; Duckett, E. B.

    2011-06-01

    Complementary gas-gun and electromagnetic pulse experiments have yielded data regarding the dynamic mechanical behavior for poled and unpoled specimens of a PZT (52 wt% lead zirconate plus 48 wt% lead titanate) ferroelectric ceramic subjected to shock and intermediate-strain-rate ramp wave (i.e., quasi-isentropic) loading. For each experiment, velocity interferometer (VISAR) diagnostics provided time-resolved measurements of sample response for conditions nominally involving one-dimensional (i.e., uniaxial strain) compression and release. Wave profiles obtained during the shock experiments have been analyzed to assess the Hugoniot Elastic Limit (HEL), Hugoniot equation of state, spall strength, and high-pressure yield strength of PZT. Profiles from the ramp wave experiments have been processed to determine the locus of isentropic stress-strain states generated in PZT for deformation rates substantially lower than those associated with shock loading.

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

    Microsoft Academic Search

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

    2000-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Xu, Fei

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

  18. Titan

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  19. Modified Johnson model for ferroelectric lead lanthanum zirconate titanate at very high fields and below Curie temperature.

    SciTech Connect

    Narayanan, M.; Tong, S.; Ma, B.; Liu, S.; Balachandran, U. (Energy Systems)

    2012-01-01

    A modified Johnson model is proposed to describe the nonlinear field dependence of the dielectric constant ({var_epsilon}-E loop) in ferroelectric materials below the Curie temperature. This model describes the characteristic ferroelectric 'butterfly' shape observed in typical {var_epsilon}-E loops. The predicted nonlinear behavior agreed well with the measured values in both the low- and high-field regions for lead lanthanum zirconate titanate films. The proposed model was also validated at different temperatures below the ferroelectric-to-paraelectric Curie point. The anharmonic coefficient in the model decreased from 6.142 x 10{sup -19} cm{sup 2}/V{sup 2} to 2.039 x 10{sup -19} cm{sup 2}/V{sup 2} when the temperature increased from 25 C to 250 C.

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

    SciTech Connect

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

    2006-10-09

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

  1. Optimizing Pt/TiO2 templates for textured PZT growth and MEMS devices

    NASA Astrophysics Data System (ADS)

    Potrepka, Daniel; Fox, Glenn; Sanchez, Luz; Polcawich, Ronald

    2013-03-01

    Crystallographic texture of lead zirconate titanate (PZT) thin films strongly influences piezoelectric properties used in MEMS applications. Textured growth can be achieved by relying on crystal growth habit and can also be initiated by the use of a seed-layer heteroepitaxial template. Template choice and the process used to form it determine structural quality, ultimately influencing performance and reliability of MEMS PZT devices such as switches, filters, and actuators. This study focuses on how 111-textured PZT is generated by a combination of crystal habit and templating mechanisms that occur in the PZT/bottom-electrode stack. The sequence begins with 0001-textured Ti deposited on thermally grown SiO2 on a Si wafer. The Ti is converted to 100-textured TiO2 (rutile) through thermal oxidation. Then 111-textured Pt can be grown to act as a template for 111-textured PZT. Ti and Pt are deposited by DC magnetron sputtering. TiO2 and Pt film textures and structure were optimized by variation of sputtering deposition times, temperatures and power levels, and post-deposition anneal conditions. The relationship between Ti, TiO2, and Pt texture and their impact on PZT growth will be presented.

  2. Improving yield of PZT piezoelectric devices on glass substrates

    NASA Astrophysics Data System (ADS)

    Johnson-Wilke, Raegan L.; Wilke, Rudeger H. T.; Cotroneo, Vincenzo; Davis, William N.; Reid, Paul B.; Schwartz, Daniel A.; Trolier-McKinstry, Susan

    2012-10-01

    The proposed SMART-X telescope includes adaptive optics systems that use piezoelectric lead zirconate titanate (PZT) films deposited on flexible glass substrates. Several processing constraints are imposed by current designs: the crystallization temperature must be kept below 550 °C, the total stress in the film must be minimized, and the yield on 1 cm2 actuator elements should be < 90%. For this work, RF magnetron sputtering was used to deposit films since chemical solution deposition (CSD) led to warping of large area flexible glass substrates. A PZT 52/48 film that wasdeposited at 4 mTorr and annealed at 550 °C for 24 hours showed no detectable levels of either PbO or pyrochlore second phases. Large area electrodes (1cm x 1 cm) were deposited on 4" glass substrates. Initially, the yield of the devices was low, however, two methods were employed to increase the yield to near 100 %. The first method included a more rigorous cleaning to improve the continuity of the Pt bottom electrode. The second method was to apply 3 V DC across the capacitor structure to burn out regions of defective PZT. The result of this latter method essentially removed conducting filaments in the PZT but left the bulk of the material undamaged. By combining these two methods, the yield on the large area electrodes improved from < 10% to nearly 100%.

  3. Optical and electrical properties of polycrystalline and amorphous PZT thin films prepared by the sol-gel technique

    NASA Astrophysics Data System (ADS)

    Xu, Yuhuan; Cheng, Chih-Hsing; Mackenzie, John D.

    1994-10-01

    Lead zirconate titanate thin films on silicon wafers and titanium foils were fabricated by the sol-gel technique. Polycrystalline and amorphous PZT thin films were obtained at the heat- treatment temperature of 650 degree(s)C and 400 degree(s)C, respectively. The microstructures of these films ere determined by x-ray and electron diffraction and HRTEM techniques. the optical refractive index of both polycrystalline and amorphous PZT films were measured by ellipsometer. The optical refractive index of polycrystalline films increases with increasing film thickness; however, the optical refractive index of amorphous films is independent of the film's thickness. the electrical properties of the PZT thin films were measured. for both polycrystalline and amorphous PZT thin films a ferroelectric hysteresis loop and pyroelectric current were observed. The dielectric permittivity of amorphous PZT is much lower than that of polycrystalline PZT. For the optical applications, the advantages of ferroelectriclike amorphous PZT materials are low processing temperature, ease of deposition on a variety of substrates (including glass and plastic), and transparency without grain boundaries. In this paper, the preparation, optical, and electrical characterizations, as well a microstructures of these thin films, are reported.

  4. Magnetoelectric effects in bilayers of lead zirconate titanate and single crystal hexaferrites

    E-print Network

    Srinivasan, Gopalan

    -type strontium hexaferrite SrFe12O19 has an easy c axis for mag- netization, and the Y and Z types have an easy-crystal hexagonal M-, Y-, or Z-type ferrites. Studies on Sr­Al­M, Zn2Y, or Co2Z and PZT show the weakest coupling to the low crystal symmetry and are classified as M, Y, or Z type depending on the crystal structure.9 The M

  5. Microstructural characterization of sol-gel lead-zirconate-titanate thin films

    NASA Astrophysics Data System (ADS)

    Impey, S. A.; Huang, Z.; Patel, A.; Beanland, R.; Shorrocks, N. M.; Watton, R.; Whatmore, R. W.

    1998-02-01

    The techniques of x-ray diffraction, x-ray photoelectron spectroscopy (XPS), Auger analysis, and transmission and scanning transmission electron microscopy (TEM) have been applied to the analysis of thin films of Pb(Zr0.30Ti0.70)O3 (PZT30/70) deposited at low temperatures (510 °C) by a sol-gel process onto Pt/Ti electrodes on SiO2/Si 100 substrates. It is found that the platinum film is highly oriented with the [111] axis perpendicular to the substrate plane. The ferroelectric film tends to crystallize epitaxially upon this as columnar crystals. There are indications from the TEM of the existence of a second metallic phase at the interface between the platinum and the PZT30/70 film, which may be associated with its nucleation. The TEM shows the boundaries between the individual sol-gel layers, although the growing crystallites of the PZT30/70 propagate through these boundaries unhindered. The XPS and Auger analyses have shown that Pb penetrates through the Pt layer to the underlying Ti layer, even at the low crystallization temperatures used. There is also clear evidence for diffusion of the Zr and Ti prior to, or during the crystallization process, so that the Zr migrates to the surface of each sol-gel layer. The effects of using different crystallization processes on this compositional separation and the reasons for its occurrence are discussed, as are the possible effects upon macroscopically measured ferroelectric properties.

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

    Microsoft Academic Search

    Takuro Ikeda; Yoichi Tanaka; Takako Ayakawa; Haruo Noake

    1964-01-01

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

  7. Sensitivity of PZT Impedance Sensors for Damage Detection of Concrete Structures

    PubMed Central

    Yang, Yaowen; Hu, Yuhang; Lu, Yong

    2008-01-01

    Piezoelectric ceramic Lead Zirconate Titanate (PZT) based electro-mechanical impedance (EMI) technique for structural health monitoring (SHM) has been successfully applied to various engineering systems. However, fundamental research work on the sensitivity of the PZT impedance sensors for damage detection is still in need. In the traditional EMI method, the PZT electro-mechanical (EM) admittance (inverse of the impedance) is used as damage indicator, which is difficult to specify the effect of damage on structural properties. This paper uses the structural mechanical impedance (SMI) extracted from the PZT EM admittance signature as the damage indicator. A comparison study on the sensitivity of the EM admittance and the structural mechanical impedance to the damages in a concrete structure is conducted. Results show that the SMI is more sensitive to the damage than the EM admittance thus a better indicator for damage detection. Furthermore, this paper proposes a dynamic system consisting of a number of single-degree-of-freedom elements with mass, spring and damper components to model the SMI. A genetic algorithm is employed to search for the optimal value of the unknown parameters in the dynamic system. An experiment is carried out on a two-storey concrete frame subjected to base vibrations that simulate earthquake. A number of PZT sensors are regularly arrayed and bonded to the frame structure to acquire PZT EM admittance signatures. The relationship between the damage index and the distance of the PZT sensor from the damage is studied. Consequently, the sensitivity of the PZT sensors is discussed and their sensing region in concrete is derived.

  8. Titan!

    Microsoft Academic Search

    Dennis L. Matson

    2010-01-01

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

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

    SciTech Connect

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

    2013-07-14

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

  10. Depolarization and Electrical Response of Porous PZT 95/5 Ferroelectric Ceramics under Shock Wave Compression

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Zhu; Jiang, Yi-Xuan; Zhang, Pan; Wang, Xing-Zhe; He, Hong-Liang

    2014-07-01

    The release of bound charges by shock wave loading of poled lead zirconate titanate (PZT 95/5) ferroelectric ceramics can result in a high-power electrical energy output. In this study, a theoretical formulation describing the depolarization and electrical response of porous PZT 95/5 ceramics in the normal mode to shock wave compression loading perpendicular to the polarization direction is developed. The depoling process in porous poled PZT 95/5 ceramics is analyzed by using a parallel circuit consisting of a current source, capacitance, conductance and a circuit load. This modeling takes the effects of porosity on wave velocity and remanent polarization and dielectric constant into account, and the effects of variations in dielectric constant and conductivity in the shocked region are assessed. The output current characteristics of porous PZT 95/5 ceramics under short-circuit and resistive load conditions are analyzed and compared with the experiment, with the results showing that theoretical predictions taking into consideration the porosity of ferroelectric ceramics are in close agreement with the experimentally measured electrical response of porous PZT 95/5 under shock wave compression loading.

  11. A Reusable PZT Transducer for Monitoring Initial Hydration and Structural Health of Concrete

    PubMed Central

    Yang, Yaowen; Divsholi, Bahador Sabet; Soh, Chee Kiong

    2010-01-01

    During the construction of a concrete structure, strength monitoring is important to ensure the safety of both personnel and the structure. Furthermore, to increase the efficiency of in situ casting or precast of concrete, determining the optimal time of demolding is important for concrete suppliers. Surface bonded lead zirconate titanate (PZT) transducers have been used for damage detection and parameter identification for various engineering structures over the last two decades. In this work, a reusable PZT transducer setup for monitoring initial hydration of concrete and structural health is developed, where a piece of PZT is bonded to an enclosure with two bolts tightened inside the holes drilled in the enclosure. An impedance analyzer is used to acquire the admittance signatures of the PZT. Root mean square deviation (RMSD) is employed to associate the change in concrete strength with changes in the PZT admittance signatures. The results show that the reusable setup is able to effectively monitor the initial hydration of concrete and the structural health. It can also be detached from the concrete for future re-use. PMID:22399929

  12. A reusable PZT transducer for monitoring initial hydration and structural health of concrete.

    PubMed

    Yang, Yaowen; Divsholi, Bahador Sabet; Soh, Chee Kiong

    2010-01-01

    During the construction of a concrete structure, strength monitoring is important to ensure the safety of both personnel and the structure. Furthermore, to increase the efficiency of in situ casting or precast of concrete, determining the optimal time of demolding is important for concrete suppliers. Surface bonded lead zirconate titanate (PZT) transducers have been used for damage detection and parameter identification for various engineering structures over the last two decades. In this work, a reusable PZT transducer setup for monitoring initial hydration of concrete and structural health is developed, where a piece of PZT is bonded to an enclosure with two bolts tightened inside the holes drilled in the enclosure. An impedance analyzer is used to acquire the admittance signatures of the PZT. Root mean square deviation (RMSD) is employed to associate the change in concrete strength with changes in the PZT admittance signatures. The results show that the reusable setup is able to effectively monitor the initial hydration of concrete and the structural health. It can also be detached from the concrete for future re-use. PMID:22399929

  13. Bolted joint looseness damage detection using electromechanical impedance measurements by PZT sensors

    NASA Astrophysics Data System (ADS)

    Chen, Mengqi; Xu, Bin

    2011-11-01

    Bolted joints are of great importance in steel structures. Any levels of looseness or even failure in the bolted joints if not earlier be found in time, will continuously change the connection strength and stiffness, causing cumulative damage to the structure, or even resulting in a sudden structural failure. Thus, it is crucial to develop efficient detection approach for early looseness in bolted joint. In particular, electro-mechanical impedance (EMI)-based damage detection technique which uses smart piezoelectric Lead Zirconate Titanate (PZT) patches has emerged as a potential tool for local damage detection of engineering structures. This paper presents a feasibility study on the application of an EMI-based bolted joint looseness detection with PZT patches. One steel specimen and an aluminum specimen were designed and the bolt looseness damage was introduced by loosening some connection bolts. Impedance measurement for each PZT sensor on the two sides of bolted joint with different distances from the loosened bolts was carried out on. A quantitative identification method based on a statistical damage index, the root mean square deviation (RMSD) of the EMI over different frequency bands, was proposed to assess the presence of damage. Results showed the RMSD can detect the existence of looseness damage and the sensitivity of the PZT sensors are investigated for the bolted joint structure. Also, the sensitive region of the PZT patches in different frequency ranges for both specimens were discussed. The proposed approaches have great potential to be applied in practice for the looseness detection in bolted joints.

  14. Bolted joint looseness damage detection using electromechanical impedance measurements by PZT sensors

    NASA Astrophysics Data System (ADS)

    Chen, Mengqi; Xu, Bin

    2012-04-01

    Bolted joints are of great importance in steel structures. Any levels of looseness or even failure in the bolted joints if not earlier be found in time, will continuously change the connection strength and stiffness, causing cumulative damage to the structure, or even resulting in a sudden structural failure. Thus, it is crucial to develop efficient detection approach for early looseness in bolted joint. In particular, electro-mechanical impedance (EMI)-based damage detection technique which uses smart piezoelectric Lead Zirconate Titanate (PZT) patches has emerged as a potential tool for local damage detection of engineering structures. This paper presents a feasibility study on the application of an EMI-based bolted joint looseness detection with PZT patches. One steel specimen and an aluminum specimen were designed and the bolt looseness damage was introduced by loosening some connection bolts. Impedance measurement for each PZT sensor on the two sides of bolted joint with different distances from the loosened bolts was carried out on. A quantitative identification method based on a statistical damage index, the root mean square deviation (RMSD) of the EMI over different frequency bands, was proposed to assess the presence of damage. Results showed the RMSD can detect the existence of looseness damage and the sensitivity of the PZT sensors are investigated for the bolted joint structure. Also, the sensitive region of the PZT patches in different frequency ranges for both specimens were discussed. The proposed approaches have great potential to be applied in practice for the looseness detection in bolted joints.

  15. Application of reusable PZT sensors for monitoring initial hydration of concrete

    NASA Astrophysics Data System (ADS)

    Sabet Divsholi, Bahador; Yang, Yaowen

    2009-03-01

    To increase the efficiency of in-situ casting or precast of concrete, determining the optimal time of demolding is very important for concrete suppliers. In the first few hours after mixing, the fresh concrete gradually achieves solid properties with reasonable compressive strength. Due to different type and amount of cementitious materials, concrete additives (e.g. retarders) and curing temperature, different rates of hardening are expected. In addition, some other factors like the quality of the cementitious materials further increase the uncertainty in determining appropriate time for demolding of concrete. Electro-mechanical impedance (EMI) based lead zirconate titanate (PZT) sensors have been used for damage detection and structural identification for various engineering structures. In this work, a reusable PZT sensor for monitoring initial hydration of concrete is developed, where a piece of PZT is bonded to a piece of metal with two bolts tightened inside of the holes drilled in the metal. An impedance analyzer is used to acquire the signature of this reusable sensor. During the concrete casting, the bolts and the bottom surface of the metal is set to penetrate part of the fresh concrete. At different stages of the first 48 hours after casting, the PZT signatures are acquired. A statistical analysis technique is employed to associate the change in concrete strength with the changes in the PZT admittance signatures. The results show that the developed sensor is able to effectively monitor the initial hydration of concrete, and can be detached from the concrete for future use.

  16. Processing and characterization of piezoelectric 0-3 PZT/LCT/PA composites

    NASA Astrophysics Data System (ADS)

    Babu, I.; van den Ende, D. A.; de With, G.

    2010-10-01

    PZT/LCT/PA (lead zirconate titanate Pb(Zr1-xTix)O3/Liquid crystalline thermosets/polyamide) composites of 0-3 connectivity were fabricated by hot-pressing. Commercially available PZT powder was calcined at different temperatures for the optimization of the composite properties. The phase transition during calcination of the powder was studied by x-ray diffraction and the particle size by light scattering and scanning electron microscopy. The relative permittivity ?r, piezoelectric charge constant d33, conductivity ? and elastic modulus E of the composites were found to increase with increasing ceramic volume fraction phiv. The obtained d33 and g33 values of this newly developed PZT/LCT/PA composite with 50 vol% PZT using a low poling voltage of 60 kV cm-1 and poling time of 30 min are 42 pC N-1 and 65 mV m N-1, respectively, which are high values for this volume fraction in comparison with the other 0-3 composites reported. Good agreement was found between the experimental data of relative permittivity and piezoelectric constants with several theoretical models (Jayasundere, Yamada and Lichtenecker) of 0-3 composites. In order to assess the correlation of the experimental data with the theoretical models, the experimental data obtained from PZT/PA composites were also included.

  17. Application of Multiplexed FBG and PZT Impedance Sensors for Health Monitoring of Rocks

    PubMed Central

    Yang, Yaowen; Annamdas, Venu Gopal Madhav; Wang, Chao; Zhou, Yingxin

    2008-01-01

    Reliable structural health monitoring (SHM) including nondestructive evaluation (NDE) is essential for safe operation of infrastructure systems. Effective monitoring of the rock components of civil infrastructures such as tunnels and caverns remains challenging. The feasibility of employing smart optical fibre sensor (OFS) and piezoelectric impedance sensor made up of lead zirconate titanate (PZT) for comprehensive health monitoring of rocks, covering load history monitoring/retrieval as well as damage assessment is presented in this paper. The rock specimens are subjected to cyclic loading and their conditions are continuously monitored using OFS and PZT sensors. OFS based multiplexed fibre Bragg grating (FBG) sensors are surface bonded on the rock specimens. Their strain sensing performance is compared with the conventional electric strain gauges (ESGs). In addition, PZT patches are also bonded on the specimens to study the damage pattern during different loading cycles. Unlike the FBGs or ESGs, PZT patches are used as bi-functional sensors and actuators, enabling them to be efficient detectors of incipient damages using the principle of electromechanical impedance. The experimental study demonstrated superior performance of these smart FBG and PZT impedance sensors. This work is expected to be useful for SHM based NDE application of rock structures such as caverns and tunnels.

  18. Ferroelectric/Ferroelastic domain wall motion in dense and porous tetragonal lead zirconate titanate films.

    PubMed

    Johnson-Wilke, Raegan L; Wilke, Rudeger H T; Wallace, Margeaux; Rajashekhar, Adarsh; Esteves, Giovanni; Merritt, Zachary; Jones, Jacob L; Trolier-McKinstry, Susan

    2015-01-01

    Direct evidence of ferroelectric/ferroelastic domain reorientation is shown in Pb(Zr0.30Ti0.70)O3 (PZT30/70) thin films clamped to a rigid silicon substrate using in situ synchrotron X-ray diffraction during application of electric fields. Both dense films and films with 3 to 4 vol% porosity were measured. On application of electric fields exceeding the coercive field, it is shown that the porous films exhibit a greater volume fraction of ferroelastic domain reorientation (approximately 12 vol% of domains reorient at 3 times the coercive field, Ec) relative to the dense films (~3.5 vol% at 3Ec). Furthermore, the volume fraction of domain reorientation significantly exceeded that predicted by linear mixing rules. The high response of domain reorientation in porous films is discussed in the context of two mechanisms: local enhancement of the electric field near the pores and a reduction of substrate clamping resulting from the lowering of the film stiffness as a result of the porosity. Similar measurements during weak-field (subcoercive) amplitudes showed 0.6% volume fraction of domains reoriented for the porous films, which demonstrates that extrinsic effects contribute to the dielectric and piezoelectric properties. PMID:25585389

  19. Titan

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  20. INFLUENCE OF SILICON ON QUALITY FACTOR, MOTIONAL IMPEDANCE AND TUNING RANGE OF PZT-TRANSDUCED RESONATORS

    E-print Network

    Afshari, Ehsan

    Oxide, PZT, etc.) between metal electrodes [4,9]. Figure 1: 3D schematic of PZT-on-silicon length and explores the design space of PZT-only (Lead Zirconium Titanate) and PZT-on- Silicon length-extensional mode

  1. Sol-gel PZT and Mn-doped PZT thin films for pyroelectric applications

    NASA Astrophysics Data System (ADS)

    Zhang, Q.; Whatmore, R. W.

    2001-08-01

    Thin films of ferroelectric lead zirconate titanate (PbZr0.3Ti0.7O3 PZT30/70) and manganese-doped lead zirconate titanate ((Pb(Zr0.3Ti0.7)1- xMnx)O3, where x = 0.01, PM01ZT30/70; and x = 0.03, PM03ZT30/70) have been prepared using sol-gel processing techniques. These materials can be used as the pyroelectric thin films in uncooled infrared detectors. The thin films were prepared via a sol-gel route based on a hybrid solvent of methanol and ethanol with acetic acid, ethanolamine and ethylene glycol as additives. The final solution is non-moisture sensitive and stable. Films deposited on Pt/Ti/SiO2/Si substrates and annealed on a hot plate at 500-530 °C for a few minutes were seen to fully crystallize into the required perovskite phase and showed excellent ferroelectric behaviour, demonstrated by reproducible hysteresis loops (Pr = 33-37 µC cm-2, Ec( + ) = 70-100 kV cm-1, Ec(-) = -170 to -140 kV cm-1). The pyroelectric coefficient (p) was measured using the Byer-Roundy method. At 20 °C, p was 2.11×10-4 C m-2 K-1 for PZT30/70, 3.00×10-4 C m-2 K-1 for PM01ZT30/70 and 2.40×10-4 C m-2 K-1 for PM03ZT30/70 thin films. The detectivity figure-of-merit (FD) was 1.07×10-5 Pa-0.5 for PZT30/70, 3.07×10-5 Pa-0.5 for PM01ZT30/70 and 1.07×10-5 Pa-0.5 for PM03ZT30/70. These figures compare well with values reported previously.

  2. Dielectric properties and field-induced phase switching of lead zirconate titanate stannate antiferroelectric thick films on silicon substrates

    NASA Astrophysics Data System (ADS)

    Xu, Baomin; Ye, Yaohong; Cross, L. Eric

    2000-03-01

    Thick (˜5 ?m) films of antiferroelectric compositions in the lead zirconate titanate stannate family of solid state solutions have been fabricated by sol-gel methods on platinum-buffered silicon substrates. Dielectric properties, electric field induced ferroelectric polarization, and associated elastic strain and the temperature dependence of the dielectric response have been explored as a function of composition. Films with high tin content are shown to undergo a diffuse antiferroelectric-paraelectric phase transition with temperature, probably because of compositional inhomogeneity associated with the high tin content. This type of film also demonstrates a diffuse field-induced antiferroelectric-ferroelectric phase switching under high electric field with the appearance of "slim loop" double hysteresis, which can be attributed to the compositional heterogeneity and the high level of tensile stress in the film because of the thermal mismatch between the film and substrate. On the other hand, the film with high zirconium and low tin content demonstrates a typical antiferroelectric-paraelectric phase change with a sharp peak in dielectric constant on increasing temperature and a typical antiferroelectric-ferroelectric phase switching under high electric field with the appearance of "square loop" double hysteresis. Corresponding to the characteristic of polarization-field hysteresis the film with high tin content possesses a gradual increase of phase switching elastic strain with applied field, reaching a maximum strain level ˜0.38% and suitable for analogue actuation. The film with high zirconium content possesses a sharp jump of phase switching strain with applied field and reaches a maximum strain level ˜0.48%, attractive for high strain digital applications.

  3. Fabrication and Evaluation of One-Axis Oriented Lead Zirconate Titanate Films Using Metal-Oxide Nanosheet Interface Layer

    NASA Astrophysics Data System (ADS)

    Minemura, Yoshiki; Nagasaka, Kohei; Kiguchi, Takanori; Konno, Toyohiko J.; Funakubo, Hiroshi; Uchida, Hiroshi

    2013-09-01

    Nanosheet Ca2Nb3O20 (ns-CN) layers with pseudo-perovskite-type crystal configuration were applied on the surface of polycrystalline metal substrates to achieve preferential crystal orientation of Pb(Zr,Ti)O3 (PZT) films for the purpose of enhanced ferroelectricity comparable to that of epitaxial thin films. PZT films with tetragonal symmetry (Zr/Ti=0.40:0.60) were fabricated by chemical solution deposition (CSD) on ns-CN-buffered Inconel 625 and SUS 316L substrates, while ns-CN was applied on the the substrates by dip-coating. The preferential crystal growth on the ns-CN layer can be achieved by favorable lattice matching between (001)/(100)PZT and (001)ns-CN planes. The degree of (001) orientation was increased for PZT films on ns-CN/Inconel 625 and ns-CN/SUS 316L substrates, whereas randomly-oriented PZT films with a lower degree of (001) orientation were grown on bare and Inconel 625 films. Enhanced remanent polarization of 60 µC/cm2 was confirmed for the PZT films on ns-CN/metal substrates, ascribed to the preferential alignment of the polar [001] axis normal to the substrate surface, although it also suffered from higher coercive field above 500 kV/cm caused by PZT/metal interfacial reaction.

  4. Piezoelectric and ferroelectric properties of CSD-prepared PZT films and their applications

    NASA Astrophysics Data System (ADS)

    Zhong, Jian

    Lead zirconate titanate (PZT)-based thin film is one of the most used materials for microelectromechanical systems (MEMS) and ferroelectric random access memory (FeRAM). The piezoelectric and ferroelectric properties of chemically derived PZT films and their applications for micromachined gyroscopes have been studied. Highly {100}-textured PZT(52/48) films have been grown using the chemically derived seeding layer of PbxTiO3 (PxT). The effects of both Pb content and solution concentration of PbxTiO 3 on PZT films have been investigated extensively. The best PZT film in terms of {100} texture and effective transverse piezoelectric coefficient -e31,f is the one seeded with 0.02 M P1.05 T. It shows 97% of {100} texture and -13.3 C/m2 of e31,f· These values are at least in par with or even better than those reported in literature for PZT films seeded with sputtered PbTiO3. The more Pb content and the larger solution concentration of PbTiO3, the lower value of {100} texture is observed. It results from the appearance of new orientation of PbO (110) and/or PbTiO3 (101). The effect of Nb doping (0˜4%) on {100}-textured PZT(52/48) films have been investigated. High value of {100} texture in the order of 97% for all the films is obtained due to the application of 0.02 M P1.05T seeding layer. Maximum polarization Pmax, remanent polarization Pr, squareness, and coercivity Ec decrease with Nb doping level. About 5˜15% improvement in e31,f has been found for 3% Nb doping level. Nb-doped PZT(20/80) (PNZT) films without seeding layer have been grown on both sides of platinized Si substrates. The -e 3i,f of the films are in the range of 2.5˜6.4 C/m2. PZT film on one side is used for actuation and that on the other side for sensing. A linear relationship between charge and driving voltage is observed at quasi-static frequency (10 Hz) for a cantilever and the resonant frequency is determined to be 260 Hz. A meso-scale gyroscope is also fabricated by micromachining, and it resonates at 12.60 KHz. These results establish the feasibility of fabricating a sensor such as a gyroscope using double-sided PZT films on a Pt/TiOx/SiO2/Si substrate.

  5. Magnetoelectric interactions in hot-pressed nickel zinc ferrite and lead zirconante titanate composites

    SciTech Connect

    Srinivasan, G.; DeVreugd, C.P.; Flattery, C.S.; Laletsin, V.M.; Paddubnaya, N. [Department of Physics, Oakland University, Rochester, Minnesota 48309 (United States); Institute of Technical Acoustics, National Academy of Sciences of Belarus, 210717 Vitebsk (Belarus)

    2004-09-27

    The synthesis by hot pressing and wide-band (10 Hz-1 MHz) magnetoelectric (ME) characterization of bulk composites of nickel zinc ferrite Ni{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4} (NZFO) (x=0-0.5) and lead zirconate titanate (PZT) are reported. Hot-pressed samples show an order of magnitude improvement in ME voltage coefficient compared to sintered samples. Frequency dependence of ME coefficients show a three order of magnitude enhancement at electromechanical resonance. The ME coupling is maximum for samples with equal volume of ferrite and PZT. The strongest ME interactions are measured for samples of NZFO (x=0.2) and PZT.

  6. High-pressure neutron study of the morphotropic lead-zirconate-titanate: Phase transitions in a two-phase system

    NASA Astrophysics Data System (ADS)

    Frantti, J.; Fujioka, Y.; Zhang, J.; Wang, S.; Vogel, S. C.; Nieminen, R. M.; Asiri, A. M.; Zhao, Y.; Obaid, A. Y.; Mkhalid, I. A.

    2012-07-01

    The present study was dedicated to the classical piezoelectric, lead-zirconate-titanate ceramic with composition Pb(Zr0.54Ti0.46)O3 at the Zr-rich side of the morphotropic phase boundary at which two phases co-exists. The pressure-induced changes in the phase fractions were studied by high-pressure neutron powder diffraction technique up to 3 GPa and 773 K. The two co-existing phases were rhombohedral R3c and monoclinic Cm at room temperature and R3c and P4mm above 1 GPa and 400 K. The experiments show that pressure favors the R3c phase over the Cm and P4mm phases, whereas at elevated temperatures entropy favours the P4mm phase. At 1 GPa pressure, the transition to the cubic Pm3¯m phase occurred at around 600 K. Pressure lowers the Cm ?P4mm transition temperature. The Cm phase was found to continuously transform to the P4mm phase with increasing pressure, which is inline with the usual notion that the hydrostatic pressure favours higher symmetry structures. At the same time, the phase fraction of the R3c phase was increasing, implying discontinuous Cm ?R3c phase transition. This is in clear contrast to the polarization rotation model according to which the Cm would link the tetragonal and rhombohedral phases by being a phase in which the polarization would, more or less continuously, rotate from the tetragonal polarization direction to the rhombohedral direction. Pressure induces large changes in phase fractions contributing to the extrinsic piezoelectricity. The changes are not entirely reversible, as was revealed by noting that after high-pressure experiments the amount of rhombohedral phase was larger than initially, suggesting that on the Zr-rich side of the phase boundary the monoclinic phase is metastable. An important contribution to the intrinsic piezoelectricity was revealed: a large displacement of the B cations (Zr and Ti) with respect to the oxygen anions is induced by pressure.

  7. PZT Thin-Film Micro Probe Device with Dual Top Electrodes

    NASA Astrophysics Data System (ADS)

    Luo, Chuan

    Lead zirconate titanate (PZT) thin-film actuators have been studied intensively for years because of their potential applications in many fields. In this dissertation, a PZT thin-film micro probe device is designed, fabricated, studied, and proven to be acceptable as an intracochlear acoustic actuator. The micro probe device takes the form of a cantilever with a PZT thin-film diaphragm at the tip of the probe. The tip portion of the probe will be implanted in cochlea later in animal tests to prove its feasibility in hearing rehabilitation. The contribution of the dissertation is three-fold. First, a dual top electrodes design, consisting of a center electrode and an outer electrode, is developed to improve actuation displacement of the PZT thin-film diaphragm. The improvement by the dual top electrodes design is studied via a finite element model. When the dimensions of the dual electrodes are optimized, the displacement of the PZT thin-film diaphragm increases about 30%. A PZT thin-film diaphragm with dual top electrodes is fabricated to prove the concept, and experimental results confirm the predictions from the finite element analyses. Moreover, the dual electrode design can accommodate presence of significant residual stresses in the PZT thin-film diaphragm by changing the phase difference between the two electrodes. Second, a PZT thin-film micro probe device is fabricated and tested. The fabrication process consists of PZT thin-film deposition and deep reactive ion etching (DRIE). The uniqueness of the fabrication process is an automatic dicing mechanism that allows a large number of probes to be released easily from the wafer. Moreover, the fabrication is very efficient, because the DRIE process will form the PZT thin-film diaphragm and the special dicing mechanism simultaneously. After the probes are fabricated, they are tested with various possible implantation depths (i.e., boundary conditions). Experimental results show that future implantation depths should be less than 3 mm in order to guarantee the first resonant frequency above 60 kHz. Finally, a package for the PZT thin-film micro probe device is developed to ensure its proper function in an aqueous environment, such as inside of cochlea. The package is an insulation layer of parylene coating on the probe. A finite element analysis indicates that a coating thickness of less than 1 mum will reduce the PZT diaphragm displacement by less than 10%. A special fixture is designed to hold a large number of probes for parylene deposition of a thickness of 250 nm. A packaged probe is then submerged in deionized water and functions properly for at least 55 hours. Displacement and impedance of the probe are measured via a laser Doppler vibrometer and an impedance analyzer, respectively. Experimental results show that displacement of the PZT diaphragm increases about 30% in two hours, after the probe is submerged in the deionized water. The impedance measurement shows consistent trends. A hypothesis to explain this unusual phenomenon is diffusion of water molecules into the PZT thin film. High-resolution SEM images of the probe indicate presence of numerous nano-pores in the surface of the PZT thin film, indirectly confirming the hypothesis. Keywords: PZT, Thin-Film, Dual Electrodes, Parylene Coating, Aqueous Environment, Cochlear Implant

  8. Thickness dependence of electrical properties in (0 0 1) oriented lead zirconate titanate films by laser ablation

    Microsoft Academic Search

    T. J. Zhu; L. Lu; M. O. Lai; A. K. Soh

    2007-01-01

    Highly (001)-oriented Pb(Zr0.52Ti0.48)O3 (PZT) thin films with LaNiO3 (LNO) bottom electrodes have been fabricated on amorphous TiN buffered Si substrates by pulsed laser deposition. The polarization–electric field (P–E) hysteresis of the deposited PZT films with different thickness ranging from 25 to 850nm was measured. Results showed that the coercive field increases with the film thickness scaling down. No P–E loops

  9. Using PZT Grid Networks in Low Velocity Impact Studies

    NASA Astrophysics Data System (ADS)

    Carmona-Reyes, Jorge; Cook, Mike; Schmoke, Jimmy; Harper, Katie; Reay, Jerry; Matthews, Lorin; Hyde, Truell

    2004-10-01

    Orbital debris has become such a large problem that computer models, space debris tracking devices, and debris shielding processes have become a vital part of the preparation for the launch of any space mission. In order to fully understand the physics behind the damage that space debris may cause, it is first necessary to reproduce such an environment in the lab. The Center for Astrophysics, Space Physics and Engineering Research (CASPER) has completed construction and calibration of a Light Gas Gun (LGG) which is used for low velocity impact studies. The LGG was used to perform impact tests on stainless steel and aluminum disk plates, since these materials are often used in the construction of man-made structures in space. Piezoelectric lead zirconate titanate (PZT) crystals were employed to measure the momentum delivered to the plate upon impact. Multiple PZT networks were attached to the plates in order to determine the location of individual impacts. This paper will show the results of this testing on both stainless steel and aluminum disks and explain the numerical process determining the locations of the impacts.

  10. Interface magnetoelectric effect in the layered heterostructures with Co layers on the polished and ion-beam planarized ceramic PZT substrates

    NASA Astrophysics Data System (ADS)

    Stognij, Alexandre I.; Novitskii, Nickolaj; Poddubnaya, Natalia; Sharko, Sergei; Ketsko, Valerij; Mikhailov, Vladimir; Dyakonov, Vladimir; Szymczak, Henryk

    2015-01-01

    The low-frequency room temperature interface magnetoelectric (ME) effect was observed in the layered heterostructures comprising the ferromagnetic (FM) Co layers and ferroelectric (FE) ceramic substrates on the base of lead zirconate titanate PbZr0.45Ti0.55O3 (PZT). The Co films 1-12 ?m in thickness were deposited by ion-beam sputtering/deposition technics onto the 400 ?m PZT substrates. Results of X-ray, magnetic and ME experiments have shown the existence of ME effect in Co/PZT/Co and (Co/PZT/Co)3 heterostructures obtained by the above mentioned techniques being independent on ferromagnetic/ferroelectric interface roughness. The values of ME voltage coefficient in heterostructures with ion-beam planarized PZT surfaces are much higher than that in heterostructures with mechanochemically polished ceramic substrate surfaces. The heterostructures possess ME effect of the same order as those obtained by means of the mechanical bonding of FM and FE sheets with organic binders and have the typical ME hysteresis curves. The structures obtained are perspective for application as energy-independent elements in magnetic field sensors and magnetic memory.

  11. Miniature cryogenic valves for a Titan Lake sampling system

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

  12. Effect of the Magnetostrictive Layer on Magnetoelectric Properties in Lead Zirconate Titanate\\/Terfenol-D Laminate Composites

    Microsoft Academic Search

    Jungho Ryu; Shashank Priya; Alfredo Vázquez Carazo; Kenji Uchino; Hyoun-Ee Kim

    2001-01-01

    Magnetoelectric laminate composites of piezoelectric\\/magne- tostrictive materials were prepared by stacking and bonding together a PZT disk and two layers of Terfenol-D disks with different directions of magnetostriction. These composites were studied to investigate (i) dependence on the magnetos- triction direction of the Terfenol-D disk and (ii) dependence on the direction of the applied ac magnetic field. Three different types

  13. A study of PZT thin films and ferroelectric field effect transistors

    NASA Astrophysics Data System (ADS)

    Abdul Basit, Nasir

    Lead zirconate titanate (Pb(Zr,Ti)Osb3 or PZT) is a well known ferroelectric material for its high polarization values, dielectric constant, and resistivity. We have studied PZT films, and ferroelectric field effect transistors (FEFETs) incorporating PZT films. One of the primary factors in synthesis and crystallization of PZT films is the proper control of the lead content of the films. We obtained highly oriented and ferroelectric PZT thin films by RF magnetron sputtering. The stoichiometric PZT target with Zr/Ti ratio of 53/47 was used. No excess lead was used either during sputtering or during post-deposition annealing. Films deposited at 200sp°C or below crystallize into a perovskite phase on receiving anneal treatment at 590sp°C or above. The annealing study, carried out using a conventional furnace, also revealed that the perovskite formation completes during the first 5 minutes of annealing. The annealed films are highly (100) oriented on (111)-Pt coated oxidized Si substrates. Maximum polarization of 36 muC/cmsp2, remanent polarization of 20 muC/cmsp2, and coercive field of 22 kV/cm were obtained with excellent fatigue resistance. This suggests that the low thermal-budget process, low-temperature deposition and short-time anneal in a conventional furnace, with a stoichiometric target may be appropriate as a reliable, simple, and economical method of preparing PZT films. Depositions at 500sp°C or higher, however, resulted in TisbxOsby or ZrTiOsb4 films suggesting that lead was significantly lost during deposition. FEFETs provide a nonvolatile memory with a nondestructive read-out. FEFETs have been fabricated by incorporating a ferroelectric layer in the gate structure of a MOSFET but the interface problems have resulted in devices with poor characteristics. We used an MgO buffer layer between PZT film and Si substrate. A thin oxide layer was grown on Si before MgO deposition to provide a clean channel between source and drain. The devices fabricated in this way clearly show the memory effect. The theoretical aspects were studied and a model was developed for the device based on ferroelectric hysteresis curve. A good comparison between the experimental and model values was observed.

  14. PZT piezoelectric films on glass for Gen-X imaging

    NASA Astrophysics Data System (ADS)

    Wilke, Rudeger H. T.; Trolier-McKinstry, Susan; Reid, Paul B.; Schwartz, Daniel A.

    2010-09-01

    The proposed adaptive optics system for the Gen-X telescope uses piezoelectric lead zirconate titanate (PZT) films deposited on flexible glass substrates. The low softening transition of the glass substrates imposes several processing challenges that require the development of new approaches to deposit high quality PZT thin films. Synthesis and optimization of chemical solution deposited 1 ?m thick films of PbZr0.52Ti0.48O3 on small area (1 in2) and large area (16 in2) Pt/Ti/glass substrates has been performed. In order to avoid warping of the glass at temperatures typically used to crystallize PZT films ({700°C), a lower temperature, two-step crystallization process was employed. An {80 nm thick seed layer of PbZr0.30Ti0.70O3 was deposited to promote the growth of the perovskite phase. After the deposition of the seed layer, the films were annealed in a rapid thermal annealing (RTA) furnace at 550°C for 3 minutes to nucleate the perovskite phase. This was followed by isothermal annealing at 550°C for 1 hour to complete crystallization. For the subsequent PbZr0.52Ti0.48O3 layers, the same RTA protocol was performed, with the isothermal crystallization implemented following the deposition of three PbZr0.52Ti0.48O3 spin-coated layers. Over the frequency range of 1 kHz to 100 kHz, films exhibit relative permittivity values near 800 with loss tangents below 0.07. Hysteresis loops show low levels of imprint with coercive fields of 40-50 kV/cm in the forward direction and 50-70 kV/cm in the reverse direction. The remanent polarization varied from 25-35 ?C/cm2 and e31,f values were approximately -5.0 C/m2. In scaling up the growth procedure to large area films, where warping becomes more pronounced due to the increased size of the substrate, the pyrolysis and crystallization conditions were performed in a box furnace to improve the temperature uniformity. By depositing films on both sides of the glass substrate, the tensile stresses are balanced, providing a sufficiently flat surface to continue PZT deposition. The properties of the large area film are comparable to those obtained on small substrates. While sol-gel processing is a viable approach to the deposition of high quality PZT thin films on glass substrates, preliminary results using RF magnetron sputter deposition demonstrate comparable properties with a significantly simpler process that offers a superior route for large scale production.

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

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

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

  16. Photovoltaic enhancement due to surface-plasmon assisted visible-light absorption at the inartificial surface of lead zirconate-titanate film

    NASA Astrophysics Data System (ADS)

    Zheng, Fengang; Zhang, Peng; Wang, Xiaofeng; Huang, Wen; Zhang, Jinxing; Shen, Mingrong; Dong, Wen; Fang, Liang; Bai, Yongbin; Shen, Xiaoqing; Sun, Hua; Hao, Jianhua

    2014-02-01

    PZT film of 300 nm thickness was deposited on tin indium oxide (ITO) coated quartz by a sol-gel method. Four metal electrodes, such as Pt, Au, Cu and Ag, were used as top electrodes deposited on the same PZT film by sputtering at room temperature. In ITO-PZT-Ag and ITO-PZT-Au structures, the visible light (400-700 nm) can be absorbed partially by a PZT film, and the maximum efficiency of photoelectric conversion of the ITO-PZT-Ag structure was enhanced to 0.42% (100 mW cm-2, AM 1.5G), which is about 15 times higher than that of the ITO-PZT-Pt structure. Numerical simulations show that the natural random roughness of polycrystalline-PZT-metal interface can offer a possibility of coupling between the incident photons and SPs at the metal surface. The coincidence between the calculated SP properties and the measured EQE spectra reveals the SP origin of the photovoltaic enhancement in these ITO-PZT-metal structures, and the improved photocurrent output is caused by the enhanced optical absorption in the PZT region near the metal surface, rather than by the direct charge-transfer process between two materials.PZT film of 300 nm thickness was deposited on tin indium oxide (ITO) coated quartz by a sol-gel method. Four metal electrodes, such as Pt, Au, Cu and Ag, were used as top electrodes deposited on the same PZT film by sputtering at room temperature. In ITO-PZT-Ag and ITO-PZT-Au structures, the visible light (400-700 nm) can be absorbed partially by a PZT film, and the maximum efficiency of photoelectric conversion of the ITO-PZT-Ag structure was enhanced to 0.42% (100 mW cm-2, AM 1.5G), which is about 15 times higher than that of the ITO-PZT-Pt structure. Numerical simulations show that the natural random roughness of polycrystalline-PZT-metal interface can offer a possibility of coupling between the incident photons and SPs at the metal surface. The coincidence between the calculated SP properties and the measured EQE spectra reveals the SP origin of the photovoltaic enhancement in these ITO-PZT-metal structures, and the improved photocurrent output is caused by the enhanced optical absorption in the PZT region near the metal surface, rather than by the direct charge-transfer process between two materials. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr05757g

  17. Processing and properties of lead zirconate titanate thin films on gallium nitride and ruthenium by sol-gel and chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Cao, Wei

    The Pb(ZrxTi1-x)O3 (PZT) thin films are potential candidates for ferroelectric random access memory (FeRAM) devices and components for microelectromechanical systems (MEMS). For example, the PZT/GaN system is being explored as RF MEMS devices for insertion in RF communication systems. A reproducible sol-gel process was developed for the deposition of PZT films on wurtzite (0001) GaN/sapphire substrates. The composition, crystallography, and interfacial nanochemistry were evaluated by various characterization techniques. The PZT/GaN heterostructure exhibited a chemically sharp interface with insignificant interdiffusion between PZT and GaN layers. However, PZT in metal -ferroelectric -semiconductor (MFS) configuration showed lower capacitance and asymmetrical polarization hysteresis compared to PZT in metal-ferroelectric-metal configuration. Such a deviation was attributed to the high depolarization field (Edepol) within PZT. To mitigate this issue, a two-pronged approach was used. First, the calculated spatial distribution of the electric field and potential, which stem from all the charge densities within the MFS configuration, demonstrated that by adjusting controllable parameters, one can minimize Edepol and maximize polarization. Second, a robust metal-organic chemical vapor deposition (MOCVD) process was developed to fabricate high quality PZT thin films on GaN. In this experimental approach, phase-pure and highly (111) oriented PZT films were deposited on GaN/sapphire substrates by MOCVD. The orientation relationships of PZT/GaN system were determined using x-ray pole figure and high-resolution transmission electron microscopy (TEM). The nanochemistry of the PZT/GaN interface, studied using analytical TEM, indicated a chemically sharp interface with interdiffusion limited to a region below 5 nm. The properties of MOCVD-PZT on GaN are briefly compared with PZT by sol-gel processing, rf sputtering, and pulsed laser deposition. Additionally, a preliminary study on the PZT/MOCVD-Ru system was carried out to demonstrate its potential as 3-D metal/PZT/metal stacks for high density FeRAMs. The properties of PZT on as-deposited and RTA-pretreated Ru films were characterized and explained in terms of the evolved nanostructure. The PZT films on as deposited Ru, as opposed to annealed Ru, exhibited improved electrical properties. Moreover, a Ru/PZT/Ru capacitor stack, fabricated by selectively depositing Ru top electrodes on PZT, yielded a symmetric hysteresis loop with high remnant polarization of 40 muC/cm2.

  18. Large Stroke Vertical PZT Microactuator With High-Speed Rotational Scanning

    PubMed Central

    Qiu, Zhen; Rhee, Choong-Ho; Choi, Jongsoo; Wang, Thomas D.; Oldham, Kenn R.

    2014-01-01

    A thin-film piezoelectric microactuator using a novel combination of active vertical translational scanning and passive resonant rotational scanning is presented. Thin-film lead-zirconate-titanate unimorph bending beams surrounding a central platform provide nearly 200-?m displacement at 18 V with bandwidth greater than 200 Hz. Inside the platform, a mirror mount, or mirror surface, supported by silicon dioxide spring beams can be excited to resonance by low-voltage; high-frequency excitation of the outer PZT beams. Over ±5.5° mechanical resonance is obtained at 3.8 kHz and ±2 V. The combination of large translational vertical displacements and high-speed rotational scanning is intended to support real-time cross-sectional imaging in a dual axes confocal endomicroscope. PMID:25506187

  19. Development of a thick film PZT foil sensor for use in structural health monitoring applications.

    PubMed

    Pickwell, Andrew J; Dorey, Robert A; Mba, David

    2013-02-01

    Acoustic emission (AE) monitoring is a technique of growing interest in the field of nondestructive testing (NDT). The use of AE devices to monitor the health of structural components is currently limited by the cost of AE equipment, which prohibits the permanent placement of AE devices on structures for the purposes of continuous monitoring and the monitoring of areas with limited access. Micro electromechanical systems (MEMS) can provide solutions to these problems. We present the manufacture of a 4.4-?m-thick lead zirconate titanate (PZT) film on a 110-?m-thick titanium foil substrate for use as an AE sensor. The thick-film sensor is benchmarked against commercially available AE sensors in static and dynamic monitoring applications. The thick-film AE device is found to perform well in the detection of AE in static applications. A low signal-to-noise ratio is found to prohibit the detection of AE in a dynamic application. PMID:23357911

  20. Damage Evaluation Based on a Wave Energy Flow Map Using Multiple PZT Sensors

    PubMed Central

    Liu, Yaolu; Hu, Ning; Xu, Hong; Yuan, Weifeng; Yan, Cheng; Li, Yuan; Goda, Riu; Alamusi; Qiu, Jinhao; Ning, Huiming; Wu, Liangke

    2014-01-01

    A new wave energy flow (WEF) map concept was proposed in this work. Based on it, an improved technique incorporating the laser scanning method and Betti's reciprocal theorem was developed to evaluate the shape and size of damage as well as to realize visualization of wave propagation. In this technique, a simple signal processing algorithm was proposed to construct the WEF map when waves propagate through an inspection region, and multiple lead zirconate titanate (PZT) sensors were employed to improve inspection reliability. Various damages in aluminum and carbon fiber reinforced plastic laminated plates were experimentally and numerically evaluated to validate this technique. The results show that it can effectively evaluate the shape and size of damage from wave field variations around the damage in the WEF map. PMID:24463430

  1. Fabrication and characterization of micromachined high-frequency tonpilz transducers derived by PZT thick films.

    PubMed

    Zhou, Qifa; Cannata, Jonathan M; Meyer, Richard J; van Tol, David J; Tadigadapa, Srinivas; Hughes, W Jack; Shung, K Kirk; Trolier-McKinstry, Susan

    2005-03-01

    Miniaturized tonpilz transducers are potentially useful for ultrasonic imaging in the 10 to 100 MHz frequency range due to their higher efficiency and output capabilities. In this work, 4 to 10-microm thick piezoelectric thin films were used as the active element in the construction of miniaturized tonpilz structures. The tonpilz stack consisted of silver/lead zirconate titanate (PZT)/lanthanum nickelate (LaNiO3)/silicon on insulator (SOI) substrates. First, conductive LaNiO3 thin films, approximately 300 nm in thickness, were grown on SOI substrates by a metalorganic decomposition (MOD) method. The room temperature resistivity of the LaNiO3 was 6.5 x 10(-6) omega x m. Randomly oriented PZT (52/48) films up to 7-microm thick were then deposited using a sol-gel process on the LaNiO3-coated SOI substrates. The PZT films with LaNiO3 bottom electrodes showed good dielectric and ferroelectric properties. The relative dielectric permittivity (at 1 kHz) was about 1030. The remanent polarization of PZT films was larger than 26 microC/cm2. The effective transverse piezoelectric e31,f coefficient of PZT thick films was about -6.5 C/m2 when poled at -75 kV/cm for 15 minutes at room temperature. Enhanced piezoelectric properties were obtained on poling the PZT films at higher temperatures. A silver layer about 40-microm thick was prepared by silver powder dispersed in epoxy and deposited onto the PZT film to form the tail mass of the tonpilz structure. The top layers of this wafer were subsequently diced with a saw, and the structure was bonded to a second wafer. The original silicon carrier wafer was polished and etched using a Xenon difluoride (XeF2) etching system. The resulting structures showed good piezoelectric activity. This process flow should enable integration of the piezoelectric elements with drive/receive electronics. PMID:15857042

  2. Development of tough anti cavitation hydrophone by deposition of hydrothermally synthesized lead zirconate titanate poly-crystalline film on reverse surface of titanium front layer

    NASA Astrophysics Data System (ADS)

    Takeuchi, Shinichi; Ishikawa, Mutsuo; Kawashima, Norimichi; Uchida, Takeyoshi; Yoshioka, Masahiro; Kikuchi, Tsuneo; Okada, Nagaya; Kurosawa, Minoru; Kuribayashi

    2012-05-01

    It is difficult to measure the high intensity ultrasound field with generation of acoustic cavitaion, since the electrode of hydrophone will be damaged by erosion and acoustic cavitation. Therefore, we developed the original miniature hydrophone by using hydrothermally synthesized lead zirconate titanate poly-crystalline film deposited on a reverse surface of a titanium film front layer as protection layer from damage by acoustic cavitation and erosion. Our hydrophone could be used to measure the high intensity ultrasound field with generation of acoustic cavitation such as focal area of 1.6 MHz HIFU treatment equipment and in a vessel of a 47 kHz ultrasound cleaner without any damage. However, we observed the output waveform of the hydrophone without nonlinear distortion in spite of measurement in high intensity ultrasound field like focal area of 1.6 MHz HIFU treatment equipment. We considered on the cause of above problem and its improving methods by computer simulation with MASON's equivalent circuit and one dimensional acoustic transmission model for the titanium front layer. As results, it was found that the cause of above problem was decrease of its receiving sensitivity in higher frequency region. Furthermore, we could propose two types of structure of hydrophones with improved frequency characteristics of receiving sensitivities. One type of hydrophone has titanium front layer thinner than 5?m. Another type has titanium front layer with thickness of 50?m and backing material with specific acoustic impedance of about 24 MRayl.

  3. Investigations on structural and multiferroic properties of artificially engineered lead zirconate titanate-cobalt iron oxide layered nanostructures

    NASA Astrophysics Data System (ADS)

    Ortega Achury, Nora Patricia

    Mutiferroics are a novel class of next generation multifunctional materials, which display simultaneous magnetic, electric, and ferroelastic ordering, have drawn increasing interest due to their multi-functionality for a variety of device applications. Since, very rare single phase materials exist in nature this kind of properties, an intensive research activity is being pursued towards the development of new engineered materials with strong magneto-electric (ME) coupling. In the present investigation, we have fabricated polycrystalline and highly oriented PbZr0.53,Ti0.47O3--CoFe 2O4 (PZT/CFO) artificially multilayers (MLs) engineered nanostructures thin films which were grown on Pt/TiO2/SiO2/Si and La 0.5Sr0.5CoO3 (LSCO) coated (001) MgO substrates respectively, using the pulsed laser deposition technique. The effect of various PZT/CFO sandwich configurations having 3, 5, and 9 layers, while maintaining similar total PZT and CFO thickness, has been systematically investigated. The first part of this thesis is devoted to the analysis of structural and microstructure properties of the PZT/CFO MLs. X-ray diffraction (XRD) and micro Raman analysis revealed that PZT and CFO were in the perovskite and spinel phases respectively in the all layered nanostructure, without any intermediate phase. The TEM and STEM line scan of the ML thin films showed that the layered structure was maintained with little inter-diffusion near the interfaces at nano-metric scale without any impurity phase, however better interface was observed in highly oriented films. Second part of this dissertation was dedicated to study of the dielectric, impedance, modulus, and conductivity spectroscopies. These measurements were carried out over a wide range of temperatures (100 K to 600 K) and frequencies (100 Hz to 1 MHz) to investigate the grain and grain boundary effects on electrical properties of MLs. The temperature dependent dielectric and loss tangent illustrated step-like behavior and relaxation peaks near the step-up characteristic respectively. The Cole-Cole plots indicate that the most of the dielectric response came from the bulk (grains) MLs below 300 K, whereas grain boundaries and electrode-MLs effects prominent at elevated temperature. The dielectric loss relaxation peaks shifted to higher frequency side with increase in temperature, finally above 300 K, it went out experimental frequency window. Our Cole-Cole fitting of dielectric loss spectra indicated marked deviation from the ideal Debye type of relaxation which is more prominent at elevated temperature. Master modulus spectra support the observation from impedance spectra, it also indicate that the difference between C g and Cgb are higher compared to polycrystalline MLs indicating less effects of grain boundary in highly oriented MLs. We have explained these electrical properties of MLs by Maxwell-Wagner type contributions arising from the interfacial charge at the interface of the MLs structure. Three different types of frequency dependent conduction process were observed at elevated temperature (>300 K), which well fitted with the double power law, sigma(o) = sigma(0) + A 1on1 + A 2on2, it indicates conduction at: Low frequency (<1 kHz) may be due to long range ordering (frequency independent), mid frequency (<10 kHz) may be due to short range hopping, and high frequency (<1 MHz) due to the localized relaxation hopping mechanism. The last part of the thesis is devoted to the study of the multiferroic and magnetoelectric properties of the ML thin films. Both polycrystalline and highly oriented films showed well saturated ferroelectric and ferromagnetic hysteresis loops at room temperature. Temperature dependence of ferroelectric properties showed that polarization slowly decreases from 300 K to 200 K, with complete collapse of polarization at ˜ 100 K, but there was complete recovery of the polarization during heating, which was repeatable over many different experiments. At the same time, in the same temperature interval the remanent magnetization of the MLs showed slo

  4. Synthesis of lead zirconate titanate nanofibres and the Fourier-transform infrared characterization of their metallo-organic decomposition process

    NASA Astrophysics Data System (ADS)

    Wang, Yu; Santiago-Avilés, Jorge J.

    2004-01-01

    We have synthesized Pb(Zr0.52Ti0.48)O3 fibres with diameters ranging from 500 nm to several microns using electrospinning and metallo-organic decomposition techniques (Wang et al 2002 Mater. Res. Soc. Symp. Proc. 702 359). By a refinement of our electrospinning technique, i.e. by increasing the viscosity of the precursor solution, and by adding a filter to the tip of the syringe, the diameter of the synthesized PZT fibres has been reduced to the neighbourhood of 100 nm. The complex thermal decomposition was characterized using Fourier-transform infrared (FTIR) spectroscopy and x-ray diffraction (XRD). It was found that alcohol evaporated during electrospinning and that most of the organic groups had pyrolysed before the intermediate pyrochlore phase was formed. There is a good correspondence between XRD and FTIR spectra. We also verify that a thin film of platinum coated on the silicon substrate catalyses the phase transformation of the pyrochlore into the perovskite phase.

  5. High-Temperature Etching of PZT/Pt/TiN Structure by High-Density ECR Plasma

    NASA Astrophysics Data System (ADS)

    Yokoyama, Seiichi; Ito, Yasuyuki; Ishihara, Kazuya; Hamada, Kazuyuki; Ohnishi, Shigeo; Kudo, Jun; Sakiyama, Keizo

    1995-02-01

    Submicron patterning technologies for the PZT/Pt/Ti/TiN/Ti structure with a spin on glass (SOG) mask were demonstrated using a high-density ECR plasma and a high substrate temperature above 300° C. A 30%-Cl2/Ar gas was used to etch a lead zirconate titanate (PZT) film. No deposits remained, which resulted in an etched profile of more than 80°. A 40%-O2/Cl2 gas was used to etch a Pt film. The etching was completely stopped at the Ti layer. 30-nm-thick deposits remained on the sidewall. They were removed after dipping in hydrochloric acid. The etched profile of a Pt film was more than 80°. The Ti/TiN/Ti layer was etched with pure Cl2 gas. The size shift from the SOG mask was less than 0.1 µ m. Interdiffusion between SOG and PZT was not detected by transmission electron microscopy and energy dispersive X-ray spectroscopy (TEM-EDX) analysis.

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

    SciTech Connect

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

    2014-02-21

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

  7. Emission, plasma formation, and brightness of a PZT ferroelectric cathode

    SciTech Connect

    Sampayan, S.; Caporaso, G.; Trimble, D.; Westenskow, G.

    1995-04-27

    We have measured an 36-A-cm{sup {minus}2} current emission density over the surface area of an 11.4-cm{sup 2}-area Lead-Titanate- Zirconate (PZT) ferroelectric cathode with a pulsed anode-cathode (A-K) potential of 50 kV. We have also observed currents above those predicted by classical Child-Langmuir formula for a wide variety of cases. Since a plasma within the A-K gap could also lead to increase current emission we are attempting to measure the properties of the plasma near the cathode surface at emission time. In other measurements, we have observed strong gap currents in the absence of an A-K potential. Further, we continue to make brightness measurements of the emitted beam and observe spatially non-uniform emission and large shot-to-shot variation. Measurements show individual beamlets with a brightness as high 10{sup 11} Am{sup {minus}2} rad{sup {minus}2}.

  8. Influence of Sintering Conditions on Doped PZT Ceramics for Base-Metal Electrode Multilayer Actuators

    NASA Astrophysics Data System (ADS)

    Denneler, Stefan; Schuh, Carsten; Benkert, Katrin; Moos, Ralf

    2012-09-01

    The influence of sintering atmosphere and copper addition on the microstructural and piezoelectric properties of Mn-doped lead zirconate titanate ceramics (PZT) was investigated. This ceramic powder densifies below 1000°C, enabling the use of copper inner electrodes for a multilayer actuator setup. To simulate the influence of oxidized inner electrodes during sintering, different CuO contents (0 and 1 mol.%) were mixed to the precalcined Mn-doped PZT powder. Ceramic discs were sintered at 950°C in air and analogously in N2, or in steam containing N2 (25 vol.% water vapor content). The electrical characterization of the discs showed that the piezoelectric properties are influenced by the CuO addition as well as by the sintering atmospheres. The large signal piezoelectric constant d33* shows an improvement of at least 20% when CuO is added. CuO acts as a sintering aid, and especially when the ceramics are fired in steam-containing N2, anomalous grain growth occurs.

  9. Nonlinear magnetoelectric effect in PZT/Terfenol-D nanobilayer on a substrate with surface stress

    NASA Astrophysics Data System (ADS)

    Shi, Yang; Niu, Longfei; Gao, Yuanwen

    2014-07-01

    Based on a linear piezoelectric constitutive relation and a nonlinear magnetostrictive constitutive relation, a nonlinear magnetoelectric (ME) effect model for lead zirconate titanate (PZT)/Terfenol-D nanobilayer on a substrate has been developed. In this study, the nonlinear ME coefficients at bending mode for two cases (without surface stress and with surface stress) are calculated by using Gurtin-Murdoch theory. The difference between two cases and the influence of residual surface tension are discussed. At the same time, the clamping effect of the substrate on ME effect is studied by altering the thickness ratio of the substrate and selecting different substrate materials. The influences of frequency of the magnetic field, PZT volume fraction on the ME effect are investigated, respectively. Finally, the dependence of ME effect on pre-stress is presented. The results show that for the nanobilayer, both the residual surface tension and surface stress have non-ignored effects on the ME effect. Besides, the resonant frequency of the nanobilayer is very low at the bending mode, which can be enhanced by increasing the thickness ratio of the substrate. Also, the substrate can weaken the ME effect due to the clamping effect, and a more soft substrate material should be selected for large ME effect. In addition, pre-stress plays an important role in the nonlinear ME coupling effect of the model developed.

  10. PZT networks for impact studies using a one stage light gas gun

    NASA Astrophysics Data System (ADS)

    Carmona-Reyes, J.; Cook, M.; Schmoke, J.; Harper, K.; Reay, J.; Matthews, L.; Hyde, T. W.

    Orbital debris has become such a large problem that computer models, space debris tracking devices, and debris shielding processes have become a vital part of the preparation for the launch of any space mission. In order to fully understand the physics behind the damage that space debris may cause, it is necessary to reproduce such an environment in the lab. The Center for Astrophysics, Space Physics and Engineering Research (CASPER) has completed construction and calibration of a Light Gas Gun (LGG) which is used for low velocity impact studies. The LGG was used to perform impact tests on stainless steel and aluminum disk plates, since these materials are often used in the construction of man-made structures in space. Piezoelectric lead zirconate titanate (PZT) crystals were employed to measure the momentum delivered to the plate upon impact. Multiple PZT networks were attached to the plates in order to determine the location of individual impacts. This paper will show the results of this testing on both stainless steel and aluminum disks and explain the numerical process determining the locations of the impacts.

  11. Synthesis and characterization of thick PZT films via sol-gel dip coating method

    NASA Astrophysics Data System (ADS)

    Shakeri, Amid; Abdizadeh, Hossein; Golobostanfard, Mohammad Reza

    2014-09-01

    Thick films of lead zirconate titanate (PZT) offer possibilities for micro-electro-mechanical systems such as high frequency ultrasonic transducers. In this paper, crack-free thick films of PZT have been prepared up to 45 ?m thickness via modified sol-gel dip coating method. In this procedure, acetic acid-alcoholic based sol is used by applying diethanolamine (DEA) and deionized water as additives. The effects of DEA and water on the crystal structure and surface morphology of the films are investigated. The mechanisms of acetic acid and DEA complexations are introduced by using FTIR spectrometer which illustrates suitable substitution of complexing agents with alkoxide groups. DEA/(Ti + Zr) = 0.5 or water/(Ti + Zr) = 0.5 are determined as the optimum molar ratio of additives, which lead to the formation of almost pure perovskite phase with the tetragonal lattice parameters of ct = 4.16 ? and at = 4.02 ? and a distortion of 2%. Values of remanent polarization and dielectric constant of 7.8 ?C cm-2 and 1630 were obtained for 45 ?m thick films, respectively.

  12. 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.

  13. Fatigue Response of a PZT Multilayer Actuator under High-Field Electric Cycling with Mechanical Preload

    SciTech Connect

    Wang, Hong [ORNL; Wereszczak, Andrew A [ORNL; Lin, Hua-Tay [ORNL

    2009-01-01

    An electric fatigue test system has been developed for piezoelectric actuator with a mechanical loading capability. Fatigue responses of a lead zirconate titanate (PZT) multilayer actuator (MLA) with a plate-through electrode configuration have been studied under an electric field (1.7 times that of a coercive field of PZT material) and a concurrent mechanical preload (30.0 MPa). A total of 1.0x10^9 cycles were carried out. Variations in charge density and mechanical strain under a high electric field and constant mechanical loads were observed during the fatigue test. The dc and the first harmonic (at 10 Hz) dielectric and piezoelectric coefficients were subsequently characterized by using FFT (Fast Fourier Transformation). It has been observed that both the dielectric and the piezoelectric coefficients underwent a monotonic decrease prior to 2.86x10^8 cycles under the relevant preload, and then fluctuated to a certain extent. Both the dielectric loss tangent and the piezoelectric loss tangent also exhibited the fluctuations after a certain amount of drop but at different levels relative to the pre-fatigue. And finally, the results were discussed with respect to domain wall mobility, microcracking, and other pre-existing anomalies.

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

    NASA Astrophysics Data System (ADS)

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

    2011-02-01

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

  15. Optimized pyroelectric properties of 0-3 composites of PZT particles in polyurethane doped with lithium perchlorate.

    PubMed

    Ploss, Bernd; Krause, Markus

    2007-12-01

    A substantial improvement in the performance of pyroelectric 0-3 composites of ceramic particles in a polymer matrix has been achieved by doping the polymer matrix material. Readily prepared and polarized films with various volume fractions of lead zirconate-titanate (PZT) particles in polyurethane have been doped in a solution of lithium perchlorate in acetone to increase the conductivity. With an appropriate conductivity, the dielectric permittivities of the ceramic particles and the polymer matrix become matched, resulting in an improvement of the pyroelectric coefficient from about 6 microC/(m(2)K) to about 50 microC/(m(2)K). The experimental results are explained by theoretical predictions. PMID:18276541

  16. 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

  17. Real-Time, Label-Free, All-Electrical Detection of Salmonella typhimurium Using Lead Zirconate Titanate/Gold-Coated Glass Cantilevers at any Relative Humidity

    PubMed Central

    Zhu, Qing; Shih, Wan Y.; Shih, Wei-Heng

    2007-01-01

    We have examined non-insulated PZT/gold-coated glass cantilevers for real-time, label-free detection of Salmonella t. by partial dipping at any relative humidity. The PZT/gold-coated glass cantilevers were consisted of a 0.127 mm thick PZT layer about 0.8 mm long, 2 mm wide bonded to a 0.15 mm thick gold-coated glass layer with a 3.0 mm long gold-coated glass tip for detection. We showed that by placing the water level at the nodal point, about 0.8 mm from the free end of the gold-glass tip, there was a 1-hr window in which the resonance frequency was stable despite the water level change by evaporation at 20% relative humidity or higher. By dipping the cantilevers to their nodal point, we were able to do real-time, label-free detection without background resonance frequency corrections at any relative humidity. The partially dipped PZT/gold-coated glass cantilever exhibited mass detection sensitivity, ?m/?f = ?5×10?11g/Hz, and a detection concentration sensitivity, 5×103 cells/ml in 2 ml of liquid, which was about two orders of magnitude lower than that of a 5 MHz QCM. It was also about two orders of magnitude lower than the infection dosage and one order of magnitude lower that the detection limit of a commercial Raptor sensor. PMID:22872784

  18. II ECCOMAS THEMATIC CONFERENCE ON SMART STRUCTURES AND MATERIALS C.A. Mota Soares et al. (Eds.)

    E-print Network

    Mielke, Alexander

    in the 1950's, lead- ing to the widespread use of barium titanate (BaTiO3) based ceramics in capacitor titanate (PbTiO3), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), and relaxor

  19. 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.

  20. Accurate modeling of PZT-induced Lamb wave propagation in structures by using a novel spectral finite element method

    NASA Astrophysics Data System (ADS)

    Ge, Luyao; Wang, Xinwei; Wang, Feng

    2014-09-01

    This paper presents an investigation on the numerical simulation of Lamb wave propagation problems in plate-like structures. Based on the simple plate theory with six variables and extended Chebyshev nodes, a novel formulation of two-dimensional spectral finite elements (2D SFEs) with and without a lead zirconate titanate (PZT) layer is proposed. A simple technique is used in the formulations to avoid inherent thickness locking, which exists in the simple plate theory. Contrary to the existing methods, only one voltage degree of freedom is introduced for each PZT element. Formulations have been worked out in detail, and analysis of the base plates with and without PZTs has been carried out. The accuracy of the proposed 2D SFE is verified by comparing the simulations to data obtained by the finite element method-base commercial software ANSYS with very fine meshes and with existing experimental data. Numerical results indicate that the proposed method is efficient in simulating Lamb wave propagation in plate-like structures.

  1. Quick response PZT/P(VDF-TrFE) composite film pyroelectric infrared sensor with patterned polyimide thermal isolation layer

    NASA Astrophysics Data System (ADS)

    Wu, C. G.; Li, P.; Cai, G. Q.; Luo, W. B.; Sun, X. Y.; Peng, Q. X.; Zhang, W. L.

    2014-09-01

    The fabrication method and the pyroelectric response of a single element infrared sensor based lead zirconate titanate (PZT) particles and polyvinylidene fluoride P(VDF-TrFE) copolymer composite thick film is reported in this paper. A special thermal insulation structure, including polyimide (PI) thermal insulation layer and thermal insulation tanks, was used in this device. The thermal insulation tanks were fabricated by laser micro-etching technique. Voltage responsivity (RV), noise voltage (Vnoise), noise equivalent power (NEP), and detectivity (D*) of the PZT/P(VDF-TrFE) based infrared sensor are 1.2 × 103 V/W, 1.25 × 10-6 V Hz1/2, 1.1 × 10-9 W and 1.9 × 108 cm Hz1/2 W-1 at 137.3 Hz modulation frequency, respectively. The thermal time constant of the infrared sensor ?T was about 15 ms. The results demonstrate that the composite infrared sensor show a high detectivity at high chopper frequency, which is an essential advantage in infrared detectors and some other devices.

  2. Structural, electrical conduction and magnetoelectric properties of y (Ni 0.3Cu 0.4Zn 0.3Fe 2o 4)+(1- y) [50% batio 3 +50% PZT] ME composites

    NASA Astrophysics Data System (ADS)

    Jadhav, P. A.; Shelar, M. B.; Chougule, S. S.; Chougule, B. K.

    2010-02-01

    The particulate composites containing NiCuZn ferrite, barium titanate (BaTiO 3) and lead zirconate titanate (PZT) as constituents having the general formula of the system y (Ni 0.3Cu 0.4Zn 0.3Fe 2O 4)+(1- y) (50% BaTiO 3+50% PZT) with y=0.15, 0.30, 0.45 were prepared by ceramic method. The spinel and tetragonal phase formation of ferrite and ferroelectrics, respectively, was confirmed by X-ray diffraction techniques. The dc resistivity measurements were made as a function of temperature. The variation of dielectric constant (?) and tan ? with frequency was studied in the range 20 Hz-1 MHz. It shows dielectric dispersion in lower frequency region and remains almost constant at higher frequencies. The studies of ac conductivity indicate small polarons type conduction. The static magnetoelectric sensitivity factor was measured as a function of magnetic field. All the composites show decrease in ME (Magnetoelectric) coefficient with increase in magnetic field.

  3. Electrical Properties and Microstructure of Lead Zirconate Titanate Thin Film In Situ Grown by Hybrid Processing:Sol-Gel Method and Pulsed Laser Deposition

    NASA Astrophysics Data System (ADS)

    Wang, Zhan Jie; Kokawa, Hiroyuki; Maeda, Ryutaro; Ichiki, Masaaki

    2004-09-01

    Highly oriented Pb(ZrxTi1-x)O3 (PZT) thin films were in situ grown on Pt/Ti/SiO2/Si substrates by a hybrid process combining the sol-gel method and pulsed-laser deposition (PLD). Crystalline phases and preferred orientation of the PZT films were investigated by X-ray diffraction analysis. Surface morphology and microstructure were observed by scanning electron microscopy and transmission electron microscopy, respectively. Electrical properties of the films were evaluated by measuring their P-E hysteresis loops and dielectric constants. The preferred orientation of the films deposited by hybrid processing can be controlled using the layer deposited by the sol-gel method. The deposition temperature required to obtain the perovskite phase in hybrid processing is 460°C, and is significantly lower than that in the case of direct film deposition by PLD on a Pt/Ti/SiO2/Si substrate. The dielectric constant and remanent polarization of the films in situ deposited at 460°C were approximately 900 and 15 ?C/cm2, respectively.

  4. Subterahertz excitations and magnetoelectric effects in hexaferrite-piezoelectric bilayers

    E-print Network

    Srinivasan, Gopalan

    applications at subterahertz frequencies is studied. The bilayer is composed of aluminum substituted barium hexagonal ferrite BaAl2Fe10O19 and lead zirconate titanate PZT . A dc electric field applied to PZT results frequency electronic de- vices. Lead zirconate titanate PZT and lead magnesium niobate-lead titanate

  5. A three-degree-of-freedom thin-film PZT-actuated microactuator with large out-of-plane displacement

    PubMed Central

    Choi, Jongsoo; Qiu, Zhen; Rhee, Choong-Ho; Wang, Thomas; Oldham, Kenn

    2014-01-01

    A novel three degree-of-freedom microactuator based on thin-film lead-zirconate-titanate (PZT) is described with its detailed structural model. Its central rectangular-shaped mirror platform, also referred to as the stage, is actuated by four symmetric PZT bending legs such that each leg provides vertical translation for one corner of the stage. It has been developed to support real-time in vivo vertical cross-sectional imaging with a dual axes confocal endomicroscope for early cancer detection, having large displacements in three axes (z, ?x, ?y) and a relatively high bandwidth in the z-axis direction. Prototype microactuators closely meet the performance requirements for this application; in the out-of-plane (z-axis) direction, it has shown more than 177 ?m of displacement and about 84 Hz of structural natural frequency, when two diagonal legs are actuated at 14V. With all four legs, another prototype of the same design with lighter stage mass has achieved more than 430 ?m of out-of-plane displacement at 15V and about 200 Hz of bandwidth. The former design has shown approximately 6.4° and 2.9° of stage tilting about the x-axis and y-axis, respectively, at 14V. This paper also presents a modeling technique that uses experimental data to account for the effects of fabrication uncertainties in residual stress and structural dimensions. The presented model predicts the static motion of the stage within an average absolute error of 14.6 ?m, which approaches the desired imaging resolution, 5 ?m, and also reasonably anticipates the structural dynamic behavior of the stage. The refined model will support development of a future trajectory tracking controller for the system. PMID:25506131

  6. In-Situ phase and texture characterization of solution deposited PZT thin films during crystallization.

    SciTech Connect

    Brennecka, Geoffrey L.; Nittala, Krishna (University of Florida, Gainesville, FL); Jones, Jacob L. (University of Florida, Gainesville, FL)

    2010-08-01

    Ferroelectric lead zirconate titanate (PZT) thin films are used for integrated capacitors, ferroelectric memory, and piezoelectric actuators. Solution deposition is routinely used to fabricate these thin films. During the solution deposition process, the precursor solutions are spin coated onto the substrate and then pyrolyzed to form an amorphous film. The amorphous film is then heated at a higher temperature (650-700 C) to crystallize the film into the desired perovskite phase. Phase purity is critical in achieving high ferroelectric properties. Moreover, due to the anisotropy in the structure and properties of PZT, it is desirable to control the texture obtained in these thin films. The heating rate during crystallization process is known to affect the sequence of phase evolution and texture obtained in these thin films. However, to date, a comprehensive understanding of how phase and texture evolution takes place is still lacking. To understand the effects of heating rate on phase and texture evolution, in-situ diffraction experiments during the crystallization of solution deposited PZT thin films were carried out at beamline 6-ID-B, Advanced Photon Source (APS). The high X-ray flux coupled with the sophisticated detectors available at the APS synchrotron source allow for in-situ characterization of phase and texture evolution at the high ramp rates that are commonly used during processing of PZT thin films. A PZT solution of nominal composition 52/48 (Zr/Ti) was spin coated onto a platinum-coated Si substrate (Pt//TiO{sub x}//SiO{sub 2}//Si). The films were crystallized using an infrared lamp, similar to a rapid thermal annealing furnace. The ramp rate was adjusted by controlling the voltage applied to the infrared lamp and increasing the voltage by a constant step with every acquisition. Four different ramp rates, ranging from {approx}1000 C/s to {approx}1 C/s, were investigated. The sample was aligned in grazing incidence to maximize the signal from the thin films. Successive diffraction patterns were acquired with a 1s acquisition time using a MAR SX-165 CCD detector during crystallization. The sample to detector distance and the tilt rotations of the detector were determined in Fit2D{copyright} by using Al{sub 2}O{sub 3} as the calibrant. These corrections were applied to the patterns when binning the data into radial (2{theta}) and azimuthal bins. The texture observed in the thin film was qualitatively analyzed by fitting the intensity peaks along the azimuthal direction with a gaussian profile function to obtain the integrated intensity of the peaks. Data analysis and peak fitting was done using the curve fitting toolbox in MATLAB{copyright}. A fluorite-type phase was observed to form before the perovskite phase for all ramp rates. PtxPb is a transient intermetallic formed due to the interaction of the thin film and the bottom electrode during crystallization. Ramp rate was observed to significantly affect the amount of PtxPb observed in the thin films during crystallization. Ramp rate was also observed to affect the final texture obtained in the thin films. These results will be discussed in the poster in view of the current understanding of these materials.

  7. Sol-gel synthesis of high-quality SrRuO{sub 3} thin film electrodes suppressing the formation of detrimental RuO{sub 2} and the dielectric properties of integrated lead lanthanum zirconate titanate films.

    SciTech Connect

    Narayanan, M.; Tong, S.; Koritala, R.; Ma, B.; Pol, V.; Balachandran, U.

    2011-01-01

    A facile solution chemistry is demonstrated to fabricate high-quality polycrystalline strontium ruthenium oxide (SrRuO{sub 3}) thin film electrodes on silicon substrates suppressing the formation of undesired ruthenium oxide (RuO{sub 2}) for the deposition of dielectric and ferroelectric materials like lead lanthanum zirconate titanate (PLZT). The robust, highly crystalline SrRuO{sub 3} film fabrication process does not favor the formation of RuO{sub 2} because of molecular level modification of the precursors possessing analogous melting points, yielding homogeneous films. This chemistry is further understood and complemented by kinetic and thermodynamic analysis of the DTA data under nonisothermal conditions, with which the activation energies to form RuO{sub 2} and SrRuO{sub 3} were calculated to be 156 {+-} 17 and 96 {+-} 10 kJ/mol, respectively. The room-temperature resistivity of the SrRuO{sub 3} film was measured to be 850 {+-} 50 {mu}{Omega} cm on silicon (100) substrates. The dielectric properties of sol-gel-derived PLZT thin film capacitors on polycrystalline SrRuO{sub 3} electrodes were also measured to illustrate the high quality of the formed SrRuO{sub 3} bottom electrode. These results have broad implications for the expanded use of these conductive oxide electrodes in many applications that require low thermal budgets. The PLZT (8/52/48) films exhibited well-defined hysteresis loops with remanent polarization of {approx}10.5 {micro}C/cm{sup 2}, dielectric constant of >1450, dielectric loss of <0.06, and leakage current density of {approx}3.8 x 10{sup -8} A/cm{sup 2}. These dielectric properties are similar to those of PLZT on platinized silicon, indicating the high quality of the bottom conductive oxide layer. In addition, the PLZT capacitors were essentially fatigue free for >1 x 10{sup 9} cycles when deposited over an oxide electrode.

  8. Chem-prep PZT 95/5 for neutron generator applicatios : powder preparation characterization utilizing design of experiments.

    SciTech Connect

    Lockwood, Steven John; Rodman-Gonzales, Emily Diane; Voigt, James A.; Moore, Diana Lynn

    2003-07-01

    Niobium doped PZT 95/5 (lead zirconate-lead titanate) is the material used in voltage bars for all ferroelectric neutron generator power supplies. In June of 1999, the transfer and scale-up of the Sandia Process from Department 1846 to Department 14192 was initiated. The laboratory-scale process of 1.6 kg has been successfully scaled to a production batch quantity of 10 kg. This report documents efforts to characterize and optimize the production-scale process utilizing Design of Experiments methodology. Of the 34 factors identified in the powder preparation sub-process, 11 were initially selected for the screening design. Additional experiments and safety analysis subsequently reduced the screening design to six factors. Three of the six factors (Milling Time, Media Size, and Pyrolysis Air Flow) were identified as statistically significant for one or more responses and were further investigated through a full factorial interaction design. Analysis of the interaction design resulted in developing models for Powder Bulk Density, Powder Tap Density, and +20 Mesh Fraction. Subsequent batches validated the models. The initial baseline powder preparation conditions were modified, resulting in improved powder yield by significantly reducing the +20 mesh waste fraction. Response variation analysis indicated additional investigation of the powder preparation sub-process steps was necessary to identify and reduce the sources of variation to further optimize the process.

  9. RMS Titanic

    NSDL National Science Digital Library

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

  10. CRACK PROPAGATION IN PZT DCB SPECIMENS UNDER CYCLIC ELECTRIC LOADING

    Microsoft Academic Search

    I. Westram; J. Rödel

    Crack propagation in ferroelectric materials under cyclic electric and combined electro-mechanical loading has been studied by several research groups. In most experiments however, Vickers-indented surface cracks and not through-thickness cracks were used. We studied crack propagation under cyclic electric loading in a commercial, soft ferroelectric lead-zirconate-titanate material. The samples were 40mm x 5mm x 1.5mm in dimension, poled in the

  11. Theoretical model to describe dispersive nonlinear properties of lead zirconatetitanate ceramics

    E-print Network

    Theoretical model to describe dispersive nonlinear properties of lead zirconate­titanate ceramics K signals measured in lead zirconate­titanate PZT ceramics suggest the introduction of a revised theoretical

  12. The Homogenized Energy Model (HEM) for Characterizing Polarization and Strains in Hysteretic

    E-print Network

    piezoelectric materials include barium titanate (BaTiO3), lead zirconate ti- tanate or PZT (Pb(Ti1-xZx)O3) lanthanum-doped lead zirconate titanate (PLZT), and piezoelectric polymers such as polyvinylidene fluoride

  13. Scalable synthesis of morphotropic phase boundary lead zirconium titanate nanowires for energy harvesting.

    PubMed

    Zhou, Zhi; Tang, Haixiong; Sodano, Henry A

    2014-12-01

    Lead zirconium titanate (PZT) nanowires are synthesized using a scalable two-step hydrothermal reaction. The piezo-electric coupling coefficient of the PZT NWs shows the highest value for PZT nano-wires in the literature (80 ± 5 pm/V). A PZT-NW-based nanocomposite is fabri-cated to demonstrate an energy-harvesting application with an open-circuit voltage up to 7 V and a power density up to 2.4 ?W/cm(3) . PMID:25312483

  14. Statistical Emulator Construction for Nonlinear Smart Systems

    E-print Network

    as capacitors, transducers, and sensors. For example, barium titanate and lead titanate are relatively simple applications these materials are increasingly being replaced by lead zirconate titanate (PZT) and lead

  15. Non-linear constitutive modeling of ferroelectrics Chad M. Landis *

    E-print Network

    barium titanate, lead titanate and PZT. Note that only the tetragonal crystal structure is pictured constitutive response is of course dependent on the material and will differ between say glass and lead­zirconate­titanate

  16. IOP PUBLISHING JOURNAL OF PHYSICS: CONDENSED MATTER J. Phys.: Condens. Matter 20 (2008) 425206 (4pp) doi:10.1088/0953-8984/20/42/425206

    E-print Network

    Srinivasan, Gopalan

    on ME effects in nanobilayers. Systems studied so far, for examples, nickel ferrite­barium titanate (BTO ferrite on lead zirconate titanate (PZT). Both ideal and non-ideal interface coupling are considered so far include ferrite, metals or alloys for the magnetic phase and lead zirconate titanate (PZT

  17. Acta Materialia 51 (2003) 61236137 www.actamat-journals.com

    E-print Network

    Fleck, Norman A.

    form 9 July 2003; accepted 28 July 2003 Abstract The multi-axial responses of barium titanate (BaTiO3) and hard lead zirconate titanate (PZT-4D) are measured for stress and electric field loadings, and are compared to the response of soft lead zirconate titanate (PZT-5H) taken from a previous study. First, poled

  18. Three-dimensional BEM for piezoelectric fracture analysis J.A. Sanz, M.P. Ariza, J. Dominguez*

    E-print Network

    Ariza Moreno, Pilar

    loading conditions are analysed. Numerical solutions computed for prismatic cracked 3D plate problems structures. Lead zirconate titanate (PZT) is the most widely used piezoceramic and polyvinylidene fluoride

  19. Modeling Time-dependent Responses of Piezoelectric Fiber Composite

    E-print Network

    Li, Kuo-An

    2011-02-22

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

  20. Flexural deformation in a compositionally stepped ferrite and magnetoelectric effects in a composite with piezoelectrics

    E-print Network

    Srinivasan, Gopalan

    is investigated in laminates of lead zirconate titanate PZT and compositionally stepped ferrite with grading and electric subsystems and are magnetoelectric ME .1,2 Several such ferroic composites, including barium titanate, lead zir- conate titanate PZT , or lead magnesium niobate-lead titan- ate PMN

  1. The effects of non-hydrostatic compression and applied electric field on the electromechanical behavior of poled PZT 95/5-2Nb ceramic during the F{sub R1} {yields} A{sub 0} polymorphic phase transformation

    SciTech Connect

    Zeuch, D.H.; Montgomery, S.T.; Zimmerer, D.J.

    1995-10-01

    We conducted hydrostatic and constant-stress-difference (CSD) experiments at room temperature on two different sintered batches of poled, niobium-doped lead-zirconate-titanate ceramic (PZT 95/5-2Nb). The objective of this test plan was to quantify the effects of nonhydrostatic stress on the electromechanical behavior of the ceramic during the ferroelectric, rhombohedral {yields} antiferroelectric, orthorhombic (FE {yields} AFE) phase transformation. We also performed a series of hydrostatic and triaxial compression experiments in which a 1000 V potential was applied to poled specimens to evaluate any effect of a sustained bias on the transformation. As we predicted from earlier tests on unpoled PZT 95/5-2Nb, increasing the stress difference up to 200 MPa (corresponding to a maximum resolved shear stress of 100 MPa) decreases the mean stress and confining pressure at which the transformation occurs by 25--33%, for both biased and unbiased conditions. This same stress difference also retards the rate of transformation at constant pressurization rate, resulting in reductions of up to an order of magnitude in the rate of charge release and peak voltage attained in our tests. This shear stress-voltage effect offers a plausible, though qualitative explanation for certain systematic failures that have occurred in neutron generator power supplies when seemingly minor design changes have been made. Transformation strains in poled ceramic are anisotropic (differing by up to 33%) in hydrostatic compression, and even more anisotropic under non-hydrostatic stress states. Application of a 1000 V bias appears to slightly increase (by {le}2%) the transformation pressure for poled ceramic, but evidence for this conclusion is weak.

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

    NASA Astrophysics Data System (ADS)

    Leontsev, Serhiy

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

  3. Titan Arum

    Microsoft Academic Search

    Stacey Knight-Davis

    2007-01-01

    Titan Arum in the H.F. Thut Greenhouse at Eastern Illinois University is producing its first flower. The Titan Arum or Amorphophallus titanum is a flowering plant with the largest unbranched inflorescence in the world. An exhibit providing a brief history of the plant, information on its reproduction, and pictures of other specimens in bloom is located in the south lobby

  4. Enhancement of magnetoelectric coupling in functionally graded ferroelectric and ferromagnetic bilayers

    E-print Network

    Srinivasan, Gopalan

    polarization. Systems studied so far include barium titanate, lead zirconate titanate PZT , or lead magnesium ferrite and lead zirconate titanate with the grading axis perpendicular to the sample plane. Both free niobate-lead titanate PMN-PT for the piezoelectric phase and ferrites, manganites, transition metals

  5. http://journals.cambridge.org Downloaded: 25 Jul 2013 IP address: 129.2.129.152 Optimization of PbTiO3 seed layers and Pt metallization

    E-print Network

    Rubloff, Gary W.

    the entire MEMS industry through the launch of the Nintendo Wii gaming console that uses 3D MEMS accel past research results on lead zirconate titanate (PZT) using the fabrication processes at the U.S. Army used in this study, lead zirconate titanate [Pb(Zrx Ti1Ã?x)O3, PZT] whose properties have been stud- ied

  6. A continuous ultrasonic scanner for lumber grading

    E-print Network

    Mayhew, Stephen Allison

    1996-01-01

    ultrasonic systems today use piezoelectric transducers to generate ultrasonic waves. Commonly used piezoelectric materials are ceramics such as barium titanate (BaTi), lead zirconate titanate (PZT), and lead metaniobate (PMN) (Bray and Stanley, 1989...

  7. EL 2004 Toronto Sept. 2004 High luminance and efficient GaN:Eu inorganic EL devices for

    E-print Network

    Steckl, Andrew J.

    (previously, barium titanate layers were used). The PZT thick dielectric, along with the other thin filmN:Eu TDELs (figure 1). Thin (~100nm) strontium titanate (STO; r~140) films were used as charge trapping thin dielectrics. Research has led to the utilization of sol-gel based lead zirconate titanate (PZT) ceramic layers

  8. 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

  9. 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 ...

  10. RMS TITANIC

    NSDL National Science Digital Library

    klooney

    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. Introduction: You are going to be a passenger on board the RMS Titanic. You boarded the ship and set sail expecting the experience of a lifetime upon the Ship of Dreams, but what will happen next? In this project we will be exploring how the ship was structured, what activities were ...

  11. RMS Titanic

    NSDL National Science Digital Library

    Mr.Taylor

    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. Introduction: You are going to be a passenger on board the RMS Titanic. You boarded the ship and set sail expecting the experience of a lifetime upon the Ship of Dreams, but what will happen next? In this project we will be exploring how the ship was structured, what activities were ...

  12. The Titanic

    NSDL National Science Digital Library

    Ms. Van Vooren

    2007-12-04

    You will be exploring the R.M.S Titanic. This includes an individual passenger, the class system on board, the collision and warnings leading up to it, and the construction of the ship. Introduction: You are going to be a passenger on board the RMS Titanic. You boarded the ship and set sail expecting the experience of a lifetime upon the Ship of Dreams, but what will happen next? In this project we will be exploring how the ship was structured, what activities were ...

  13. Materials Letters 17 (1993) 13-20 Nosh-Holland

    E-print Network

    Ounaies, Zoubeida

    . [ 2 ] have determined the optimum microwave calcining conditions for barium strontium titanate (BSTMaterials Letters 17 (1993) 13-20 Nosh-Holland Microwave calcination lead zirconate titanate prepared (mixed oxides) as well as sol-gel prepared lead zirconate titanate (PZT) powders was investigated

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

    E-print Network

    Grujicic, Mica

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

  15. 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 ...

  16. 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

  17. Li diffusion in zircon

    Microsoft Academic Search

    D. J. CherniakE; E. B. Watson

    2010-01-01

    Diffusion of Li under anhydrous conditions at 1 atm and under fluid-present elevated pressure (1.0–1.2 GPa) conditions has\\u000a been measured in natural zircon. The source of diffusant for 1-atm experiments was ground natural spodumene, which was sealed\\u000a under vacuum in silica glass capsules with polished slabs of zircon. An experiment using a Dy-bearing source was also conducted\\u000a to evaluate possible rate-limiting effects

  18. 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

  19. Future Titan Missions

    NASA Astrophysics Data System (ADS)

    Waite, J. H.; Coustenis, A.; Lorenz, R.; Lunine, J.; Stofan, E.

    2012-04-01

    New discoveries about Titan from the Cassini-Huygens mission have led to a broad range of mission class studies for future missions, ranging from NASA Discovery class to International Flagship class. Three consistent science themes emerge and serve as a framework for discussing the various mission concepts: Goal A: Explore Titan, an Earth-Like System - How does Titan function as a system? How are the similarities and differences with Earth, and other solar system bodies, a result of the interplay of the geology, hydrology, meteorology, and aeronomy present in the Titan system?; Goal B: Examine Titan’s Organic Inventory—A Path to Prebiological Molecules - What is the complexity of Titan’s organic chemistry in the atmosphere, within its lakes, on its surface, and in its putative subsurface water ocean and how does this inventory differ from known abiotic organic material in meteorites and therefore contribute to our understanding of the origin of life in the Solar System?; and Goal C: Explore Enceladus and Saturn’s magnetosphere—clues to Titan’s origin and evolution - What is the exchange of energy and material with the Saturn magnetosphere and solar wind? What is the source of geysers on Enceladus? Does complex chemistry occur in the geyser source? Within this scientific framework the presentation will overview the Titan Explorer, Titan AND Enceladus Mission, Titan Saturn System Mission, Titan Mare Explorer, and Titan Submersible. Future timelines and plans will be discussed.

  20. Very High Frequency (Beyond 100 MHz) PZT Kerfless Linear Arrays

    PubMed Central

    Wu, Da-Wei; Zhou, Qifa; Geng, Xuecang; Liu, Chang-Geng; Djuth, Frank; Shung, K. Kirk

    2010-01-01

    This paper presents the design, fabrication, and measurements of very high frequency kerfless linear arrays prepared from PZT film and PZT bulk material. A 12-µm PZT thick film fabricated from PZT-5H powder/solution composite and a piece of 15-µm PZT-5H sheet were used to fabricate 32-element kerfless high-frequency linear arrays with photolithography. The PZT thick film was prepared by spin-coating of PZT sol-gel composite solution. The thin PZT-5H sheet sample was prepared by lapping a PZT-5H ceramic with a precision lapping machine. The measured results of the 2 arrays were compared. The PZT film array had a center frequency of 120 MHz, a bandwidth of 60% with a parylene matching layer, and an insertion loss of 41 dB. The PZT ceramic sheet array was found to have a center frequency of 128 MHz with a poorer bandwidth (40% with a parylene matching layer) but a better sensitivity (28 dB insertion loss). PMID:19942516

  1. Virtual Titanic

    NSDL National Science Digital Library

    The recent historical and cinematic fascination with the Titanic proves that the allure of this most famous luxury liner remains unsinkable. The Discovery Channel Online has created a captivating site devoted to images, movies (IPIX, QuickTime), and text describing the ship and its demise. While the site contains historical photos and lithographs of the ship as well as underwater photos and movies from a 1985 submersible mission, the unique contribution of this site is its numerous virtual images of the interior and exterior of the Titanic as well as its movies of the collision and sinking. Developed by Andrew Nelson for a CD-ROM game, the movies include a flyby of the ship, a collision movie, a listing movie, and a three-part series of the sinking. Both flat and "bubble" views of such features as the first-class cabins, the wireless room, and the grand staircase are also included. A talk-back section discusses various theories surrounding the sinking and contains several related links.

  2. Manufacturing of PZT-nickel functionally graded piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

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

    2012-05-01

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

  3. Genetic Adaptive Control for PZT Actuators

    NASA Technical Reports Server (NTRS)

    Kim, Jeongwook; Stover, Shelley K.; Madisetti, Vijay K.

    1995-01-01

    A piezoelectric transducer (PZT) is capable of providing linear motion if controlled correctly and could provide a replacement for traditional heavy and large servo systems using motors. This paper focuses on a genetic model reference adaptive control technique (GMRAC) for a PZT which is moving a mirror where the goal is to keep the mirror velocity constant. Genetic Algorithms (GAs) are an integral part of the GMRAC technique acting as the search engine for an optimal PID controller. Two methods are suggested to control the actuator in this research. The first one is to change the PID parameters and the other is to add an additional reference input in the system. The simulation results of these two methods are compared. Simulated Annealing (SA) is also used to solve the problem. Simulation results of GAs and SA are compared after simulation. GAs show the best result according to the simulation results. The entire model is designed using the Mathworks' Simulink tool.

  4. Impact Shock Microstructures in Apollo 14 Zircons

    NASA Astrophysics Data System (ADS)

    Crow, C. A.; Moser, D. E.; McKeegan, K. D.; Barker, I.

    2014-09-01

    We conducted a survey of Apollo 14 lunar zircon to search for shock features common in zircons from terrestrial impact structures. We observed a wide range of microstructural states including microstructures not previously reported in any zircon.

  5. 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)

  6. Information Titan Parents

    E-print Network

    de Lijser, Peter

    for Parents of Commuter Students 3 Titan Parents Profile & State Relations & Advocacy 4 College Parenting 101 Titan Parents Connection President Gordon's Farewell Cal State Fullerton President Milton A. Gordon President #12;Welcome Titan Parents! On behalf of California State University, Fullerton, welcome

  7. 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

  8. Tides in Titan

    NASA Technical Reports Server (NTRS)

    Rappaport, Nicole J.

    1997-01-01

    Tides raised in Titan by Saturn give rise to a static and a periodic deformation; both will be measured with Doppler tracking during the CASSINI Tour of the Saturnian System. The latter deformation is due to the significant eccentricity of Titan's orbit and has a frequency equal to the orbital angular velocity of Titan.

  9. 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.

  10. Measured displacement energies of oxygen ions in titanates and zirconates

    Microsoft Academic Search

    Katherine L Smith; Michael Colella; Ronald Cooper; Eric R Vance

    2003-01-01

    Optical emission spectra in the 300–700 nm range were collected from four perovskite-structured materials (CaTiO3, SrTiO3, BaTiO3 and CaZrO3), a pyrochlore-structured material (La2Zr2O7) and zirconolite (CaZrTi2O7), using either a Febetron 706 variable energy pulsed-electron-beam generator (pulse duration 3 ns) or a Vickers pulsed-electron LINAC (pulse duration 0.5 ?s). The long-lived emissions (up to microseconds after the electron pulse) consist of

  11. Ferroelectric Phase Transition in Lead Zirconate Titanate under High Pressure

    Microsoft Academic Search

    Mitsuhiko Hayashi; Kanemitsu Hasegawa; Ken Hayashi

    1977-01-01

    The ferroelectric phase transition temperature Tc was measured for a ceramic sample of (Pb0.97Sr0.03)Zr0.51Ti0.49O3+2 wt% Nb2O5+0.45 wt% MnO2 under pressure in the range from 10 kbar to 55 kbar. The pressure was generated in a pyrophyllite cell inserted in a tetrahedral multianvil apparatus. The transition temperature was determined from the anomaly in the dielectric constant. The initial rate of change

  12. Mixed electron emission from lead zirconate{endash}titanate ceramics

    SciTech Connect

    Zhang, W.; Huebner, W. [The Department of Ceramic Engineering, University of Missouri-Rolla, Rolla, Missouri65401 (United States)] [The Department of Ceramic Engineering, University of Missouri-Rolla, Rolla, Missouri65401 (United States); Sampayan, S.E. [University of California, Lawrence Livermore National Laboratory, Livermore, California94551 (United States)] [University of California, Lawrence Livermore National Laboratory, Livermore, California94551 (United States); Krogh, M.L. [Allied Signal Federal Manufacturing Technologies, Kansas City, Missouri64141 (United States)] [Allied Signal Federal Manufacturing Technologies, Kansas City, Missouri64141 (United States)

    1998-06-01

    Simultaneous ferroelectric and plasma emission from Pb(Zr,Ti)O{sub 3} was observed with only a negative driving pulse applied to the sample, and without an extraction potential on the electron collector. Plasma emission was a strong, inconsistent, and self-destructive process. In addition, a positive ion current was detected. Comparatively, ferroelectric emission was a relatively stable self-emission process, exhibiting no apparent delay time, and no positive ion current. The relationship between the switching and emission current of ferroelectric samples measured simultaneously cannot only be used to determine the existence of ferroelectric emission, but can also give direction to choosing suitable ferroelectric materials for emitter applications. {copyright} {ital 1998 American Institute of Physics.}

  13. Oxygen isotope geochemistry of zircon

    NASA Astrophysics Data System (ADS)

    Valley, John W.; Chiarenzelli, Jeffrey R.; McLelland, James M.

    1994-09-01

    The high-temperature and small sample size of an I.R. laser system has allowed the first detailed study of oxygen isotope ratios in zircon. Low-magnetism zircons that have grown during metamorphism in the Adirondack Mts., N.Y. preserve primary delta (O-18) values and low magnetism igneous zircons are likewise primary, showing no significant affect due to subsequent granulite facies metamorphism. The measured fractionation between zircon and garnet is delta (Gt-Zrc) = 0.0 + or - 0.2/mil (1(sigma)) for most low-magnetism zircons in meta-igneous rocks. The consistency of this value indicates equilibration at temperatures of 700 - 1100 C and little or no change in the equilibrium fractionation over this temperature range. In contrast, detrital low-magnetism zircons in quartzite preserve igneous compositions, up to 4/mil out of equilibrium with host quartz, in spite of granulite facies metamorphism. The oxygen isotope composition of zircon can be linked to U-Pb ages and can `see through' metamorphism, providing a new tool for deciphering complex igneous, metamorphic and hydrothermal histories. Zircons separated by magnetic susceptibility show a consistent correlation. Low-magnetism zircons have the lowest uranium contents, the most concordant U-Pb isotopic compositions, and primary delta (O-18) values. In contrast, high-magnetism zircons are up to 2/mil lower in delta (O-18) than low-magnetism zircons from the same rock. The resetting of oxygen isotope ratios in high-magnetism zircons is caused by radiation damage which creates microfractures and enhances isotopic exchange. Zircons from the metamorphosed anorthosite-mangerite-charnocite-granite (AMCG) suite of adirondacks have previously been dated (1125-1157 Ma) and classified as igneous, metamorphic or disturbed based on their physical and U-Pb isotopic characteristics. Low-magnetism zircons from the AMCG suite have high, nearly constant values of delta (O-18) that average 8.1 + or - 0.4/mil(1 sigma) for samples ranging from 39 to 75 wt% SiO2. Only olivine metagabbros have lower average values (6.4/mil), consistent with the hypothesis that they represent nearly pristine samples of the anorthosite's parent magma. Whole-rock values of delta (O-18) are also high in the AMCG suite and increase with SiO2 content, as predicted for a process of assimilation and fractional crystallization. Taken together, these data suggest that the elevated values of oxygen isotope ratios result from partial melting and contamination involving metasediments in the deep crust, before the crystallization of zircon. More normal values elsewhere in the Grenville Province record deep-seated, pre-1150 Ma regional differences.

  14. Intensive Titan exploration begins.

    PubMed

    Mahaffy, Paul R

    2005-05-13

    The Cassini Orbiter spacecraft first skimmed through the tenuous upper atmosphere of Titan on 26 October 2004. This moon of Saturn is unique in our solar system, with a dense nitrogen atmosphere that is cold enough in places to rain methane, the feedstock for the atmospheric chemistry that produces hydrocarbons, nitrile compounds, and Titan's orange haze. The data returned from this flyby supply new information on the magnetic field and plasma environment around Titan, expose new facets of the dynamics and chemistry of Titan's atmosphere, and provide the first glimpses of what appears to be a complex, fluid-processed, geologically young Titan surface. PMID:15890870

  15. Shear piezoelectric coefficients of PZT, LiNbO3 and PMN-PT at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Bukhari, Syed; Islam, Md; Haziot, Ariel; Beamish, John

    2014-12-01

    Piezoelectric transducers are used to detect stress and to generate nanometer scale displacements but their piezoelectric coefficients decrease with temperature, limiting their performance in cryogenic applications. We have developed a capacitive technique and directly measured the temperature dependence of the shear coefficient d15 for ceramic lead zirconium titanate (PZT), 41° X-cut lithium niobate (LiNbO3) and single crystal lead magnesium niobium-lead titanate (PMN-PT). In PZT, d15 decreases nearly linearly with temperature, dropping by factor of about 4 by 1.3 K. LiNbO3 has the smallest room temperature d15, but its value decreased by only 6% at the lowest temperatures. PMN-PT had the largest value of d15 at room temperature (2.9 × 10?9 m/V, about 45 times larger than for LiNbO3) but it decreased rapidly below 75 K; at 1.3 K, d15 was only about 8% of its room temperature value.

  16. Change from 3D-Ising to Random Field-Ising-Model Criticality in a Uniaxial Relaxor Ferroelectric

    E-print Network

    Osnabrück, Universität

    Change from 3D-Ising to Random Field-Ising-Model Criticality in a Uniaxial Relaxor Ferroelectric T piezoelectric sensors or actuators, where ceramics of lead zirconate titanate (PZT) or lead lanthanum zirconate titanate (PLZT) are extensively used [3], to optical applications like phase conjugated mirrors, where

  17. MEDYNA 2013: 1st Euro-Mediterranean Conference on Structural Dynamics and Vibroacoustics

    E-print Network

    Boyer, Edmond

    of the system. We will present here a sensitivity analysis of a 3D cantilever beam controlled by a shunted the last thirty years, vibration control using piezoelectric materials such as lead zirconate titanate (PZT

  18. First In Vivo Use of a Capacitive Micromachined Ultrasound

    E-print Network

    Khuri-Yakub, Butrus T. "Pierre"

    - diofrequency;RFA,radiofrequencyablation; TSI, thermal strain imaging; 3D, 3-dimen- sional; 2D, 2-dimensional, electrocardiographic; ICE, intracardiac echocardiography; ML, micro- linear; PZT, lead zirconate titanate; RF, ra

  19. A Low Cost Coarse/Fine Piezoelectrically Actuated Microgripper With Force Measurement

    E-print Network

    Boyer, Edmond

    functions. These components have complex 3D shapes. This is why new micromanipulation technologies must to the cantilever. The cantilever is made up of two PZT (lead zirconate titanate) layers equipped with electrodes

  20. Etching fission tracks in zircons

    USGS Publications Warehouse

    Naeser, C.W.

    1969-01-01

    A new technique has been developed whereby fission tracks can be etched in zircon with a solution of sodium hydroxide at 220??C. Etching time varied between 15 minutes and 5 hours. Colored zircon required less etching time than the colorless varieties.

  1. Displacement amplification of electroactive materials using the cymbal flextensional transducer

    Microsoft Academic Search

    R. J Meyer; A Dogan; C Yoon; S. M Pilgrim; R. E Newnham

    2001-01-01

    High performance electroactive materials were studied as the driver element for the “cymbal” flextensional transducer. The compositions included were commercially available Navy Type I and PKI552 lead zirconate titanate (PZT) piezoceramic, relaxor lead magnesium niobate-lead titanate (PMN-PT) ceramic, lead zinc niobate-lead titanate (PZN-PT) single crystal, and lead lanthanum stannate zirconate titanate (PLSnZT) ceramic with antiferroelectric to ferroelectric transitions. Displacement amplifications

  2. PZT-5A4/PA and PZT-5A4/PDMS piezoelectric composite bimorphs

    NASA Astrophysics Data System (ADS)

    Babu, I.; Hendrix, M. M. R. M.; de With, G.

    2014-02-01

    Disc type reinforced piezoelectric composite bimorphs with series connection were designed and the performance was investigated. The composite bimorphs (PZT/PA and PZT/PDMS (40/60 vol%)) were successfully fabricated by a compression molding and solution casting technique. The charge developed at an applied force of 150 N is 18150 pC (PZT/PA) and 2310 pC (PZT/PDMS), respectively. Electric force microscopy (EFM) is used to study the structural characterization and piezoelectric properties of the materials realized. A clear inverse piezoelectric effect was observed when the bimorphs were subjected to an electric field stepped up through 2, 6 and 10 V, indicating the net polarization direction of the different ferroelectric domains. The as-developed bimorphs have the basic structure of a sensor and actuator, and, since they do not use any bonding agent for bonding, they can provide a valuable alternative to the present bimorphs where bonding processes are required for their realization that can limit their application at high temperature.

  3. 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.

  4. 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.

  5. Digital Object Identifier (DOI) 10.1007/s00205-007-0096-y Arch. Rational Mech. Anal. 189 (2008) 5995

    E-print Network

    Bhattacharya, Kaushik

    the theory by studying oxygen vacancies in barium titanate. We find the formation of depletion layers separated by domain walls. As an example, barium titanate (BaTiO3), an exten- sively investigated,25,34,49]. For example, lead zirconate titanate (PZT) is used in ultrasonic transducers and actuators for its

  6. Science in China Series E: Technological Sciences 2009 SCIENCE IN CHINA PRESS

    E-print Network

    Melnik, Roderick

    | vol. 52 | no. 1 | 141-147 structures[3,4] such as BaTiO3 (barium titanate materials). It was reported titanate (PZT), which is a solid solution of lead titanate and lead zirconate, is probably the most widely

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

    E-print Network

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

  8. Titan's organic chemistry

    Microsoft Academic Search

    C. Sagan; W. R. Thompson; B. N. Khare

    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

  9. HASI Experiment to Titan

    Microsoft Academic Search

    M. Fulchignoni; F. Ferri; G. Colombatti; J. C. Zarnecki; H. M. Harri; M. Hamelin; J. J. Lopez-Moreno; K. Schwingenshuh; F. Angrilli

    2005-01-01

    The Huygens Atmospheric Structure Instrument (HASI) is a multi sensor package which has been designed to measure the physical quantities characterizing Titan's atmosphere during the Huygens entry and descent phases and at the surface. HASI's suite of sensors measured the physical and electrical properties of Titan's atmosphere. Profiles of temperature, pressure, density, atmospheric conductivity have been collected. HASI investigated the

  10. INSIDE THIS Titan Parents

    E-print Network

    de Lijser, Peter

    INSIDE THIS ISSUE: Titan Parents: New Initiatives 1 Homecoming 2010: Parents Show Parent Connection A P R I L 2 0 1 0V O L U M E 1 , I S S U E 2 Titan Parents: New Initiatives for a New Year Over the past year, California State University, Fullerton has championed efforts to make parent

  11. Phosphorus chemistry on Titan

    NASA Astrophysics Data System (ADS)

    Pasek, Matthew A.; Mousis, Olivier; Lunine, Jonathan I.

    2011-04-01

    Phosphorus is a key element in biology and acts in many critical biochemical functions. The chemistry of phosphorus in the outer Solar System has not yet been quantified, hence the astrobiological relevance of phosphorus to possible life on places like Titan is unconstrained. We evaluate phosphorus chemistry on Titan using a combination of modeling and laboratory techniques. We show that phosphorus chemistry on Titan consists of exogenous phosphates and reduced oxidation state phosphorus compounds, and accretionary phosphine. Accretionary phosphorus is shown to be delivered primarily by rocks and ices in the saturnian sub-nebula, and heating during accretion concentrates phosphine in the crust of Titan. The exogenous compounds are capable of performing biologically-relevant chemistry, however they are active only in environments with substantial liquid water, either pure, or as a mixture with NH 3 or nitrile compounds. In contrast, we show that phosphine is soluble in methane and ethane on Titan's surface, hence phosphine likely participates in the hydrocarbon cycle on Titan. The lack of mobility of phosphate compounds on Titan's surface suggests that if life is present on Titan, it must have a fundamentally different biochemistry than does terrestrial life.

  12. Titan Airship Explorer

    Microsoft Academic Search

    Jeffery L. Hall; Viktor V. Kerzhanovich; J. A. Jones; J. A. Cutts; A. A. Yavrouian; A. Colozza; R. D. Lorenz

    2002-01-01

    Saturn's moon Titan is considered to be one of the prime locations for understanding the origins of life due to its rich environment of organic chemicals. A unique combination of dense atmosphere (more than four times that of the Earth), low gravity (one-sixth of that on the Earth) and small temperature variations makes Titan well-suited for studies with buoyant robotic

  13. Clash of the Titans

    ERIC Educational Resources Information Center

    Subramaniam, Karthigeyan

    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 the inherent power and potential of both strategies. In the lesson, "Clash of the Titans,"…

  14. Titan's Exotic Weather

    NASA Astrophysics Data System (ADS)

    Griffith, Caitlin A.

    2006-09-01

    Images of Titan, taken during the joint NASA and European Space Agency Cassini-Huygens mission, invoke a feeling of familiarity: washes wind downhill to damp lakebeds; massive cumuli form and quickly dissipate, suggestive of rain; and dark oval regions resemble lakes. These features arise from Titan's unique similarity with Earth: both cycle liquid between their surfaces and atmospheres, but in Titan's cool atmosphere it is methane that exists as a gas, liquid, and ice. While Titan enticingly resembles Earth, its atmosphere is 10 times thicker, so that its radiative time constant near the surface exceeds a Titan year, and prohibits large thermal gradients and seasonal surface temperature variations exceeding 3K. Titan also lacks oceans - central to Earth's climate - and instead stores much of its condensible in its atmosphere. As a result, Titan's weather differs remarkably from Earth's. Evidence for this difference appears in the location of Titan's large clouds, which frequent a narrow band at 40S latitude and a region within 30 latitude of the S. Pole. Ground-based and Cassini observations, combined with thermodynamic considerations, indicate that we are seeing large convective cloud systems. Detailed cloud models and general circulation models further suggest that these are severe rain storms, which will migrate with the change in season. Outside these migrating "gypsy" cloud bands, the atmosphere appears to be calm, humid and thus frequented by thin stratiform clouds. An intriguingly alien environment is predicted. Yet, the combined effects of Titan's patchy wet surface, atmospheric tides, possible ice volcanoes, and detailed seasonal variations remain unclear as we have witnessed only one season so far. This talk will review observations of Titan's lower atmosphere and modeling efforts to explain the observations, and explore the questions that still elude us.

  15. Spatially selective photochemical reduction of silver on nanoembossed ferroelectric PZT nanowires.

    PubMed

    Shen, Zhenkui; Chen, Guoping; Chen, Zhihui; Qu, Xinping; Chen, Yifang; Liu, Ran

    2011-05-01

    It is well known that photochemical reaction in an aqueous solution can be chosen by selectively patterning the domain structures of ferroelectrics. In this work, we investigate the photochemically induced deposition of Ag particles on ferroelectric lead zirconate titanate [Pb(Zr(x),Ti(1?-?x))O(3)] nanowires fabricated by nanoembossing technology. The photochemical reduction of Ag particles is found to occur preferentially along the embossed nanowires. By imaging domain configurations of the embossed films using the piezoresponse force microscope, the spatially selective deposition of Ag particles can be associated with the underlying ferroelectric domain structures created by the nanoembossing process. The controllable and selective deposition of metal species onto nanoembossed ferroelectric nanostructures without the need for an external electrical field is promising for providing a new route to nanoferroelectric lithography. PMID:21476531

  16. Dielectric and acoustical high frequency characterisation of PZT thin films

    NASA Astrophysics Data System (ADS)

    Conde, Janine; Muralt, Paul

    2010-02-01

    Pb(Zr, Ti)O3 (PZT) is an interesting material for bulk acoustic wave resonator applications due to its high electromechanical coupling constant, which would enable fabrication of large bandwidth frequency filters. The major challenge of the PZT solid solution system is to overcome mechanical losses generally observed in PZT ceramics. To increase the understanding of these losses in textured thin films, thin film bulk acoustic resonators (TFBAR's) based on PZT thin films with compositions either in the tetragonal region or at the morphotropic phase boundary and (111) or {100} textures were fabricated and studied up to 2 GHz. The dielectric and elastic materials coefficients were extracted from impedance measurements at the resonance frequency. The dispersion of the dielectric constant was obtained from impedance measurements up to 2 GHz. The films with varying compositions, textures and deposition methods (sol-gel or sputtering) were compared in terms of dielectric and acoustical properties.

  17. 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

  18. 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.

  19. Finite element analysis for PZT actuated deformable polishing lap

    NASA Astrophysics Data System (ADS)

    Hu, Ziqiang

    2010-10-01

    In aspheric mirror polishing progress, the deformable polishing lap can change the lap surface to fit the surface of aspheric optical mirror. A novel method of designing deformable polishing lap is brought forward by using PZT actuator. It consists of an aluminum disk which can change surface profile continuously under the control of PZT actuators. When the deformable aspherical polishing lap moves on the surface of aspherical mirror, the needed deformation of each PZT actuator is calculated at any location. After each PZT actuator deforming, the surface profile of deformable aspherical polishing lap is changed to an off-axis surface of aspheric optical mirror at that location. In this paper, the rational of novel deformable polishing lap is introduced, and the calculation formula of PZT actuator deformation is explored also. By using finite element method (FEM), the deforming capability of the novel deformable polishing lap is simulated to reform a hyperboloid mirror with diameter 350mm,k=-1.112155,R=840.0 mm. The results of two type of PZT actuator arrangement are compared and analyzed. The results show that the novel deformable polishing lap can reshape to fit the surface of aspheric mirror and the RMS is less than 2um.

  20. Lunar Zircons: What's the Big Picture?

    NASA Astrophysics Data System (ADS)

    Crow, C. A.; McKeegan, K. D.; Moser, D. E.

    2015-02-01

    An extensive U-Pb, REE, and microstructural survey of Apollo zircons from which we can draw constraints regarding the duration of KREEP magmatism, zircon formation mechanisms, and possibly the early impact history of the Moon.

  1. The astrobiology of Titan

    NASA Astrophysics Data System (ADS)

    Raulin, F.; Coll, P.; Cabane, M.; Hebrard, E.; Israel, G.; Nguyen, M.-J.; Szopa, C.; Gpcos Team

    Largest satellite of Saturn and the only satellite in the solar system having a dense atmosphere, Titan is one of the key planetary bodies for astrobiological studies, due to several aspects: Its analogies with planet Earth, in spite of much lower temperatures, The Cassini-Huygens data have largely confirmed the many analogies between Titan and our own planet. Both have similar vertical temperature profiles, (although much colder, of course, on Titan). Both have condensable and non condensable greenhouse gases in their atmosphere. Both are geologically very active. Furthermore, the data also suggest strongly the presence of a methane cycle on Titan analogous to the water cycle on Earth. The presence of an active organic chemistry, involving several of the key compounds of prebiotic chemistry. The recent data obtained from the Huygens instruments show that the organic matter in Titan low atmosphere (stratosphere and troposphere) is mainly concentrated in the aerosol particles. Because of the vertical temperature profile in this part of the atmosphere, most of the volatile organics are probably mainly condensed on the aerosol particles. The nucleus of these particles seems to be made of complex macromolecular organic matter, well mimicked in the laboratory by the "Titan's tholins". Now, laboratory tholins are known to release many organic compounds of biological interest, such as amino acids and purine and pyrimidine bases, when they are in contact with liquid water. Such hydrolysis may have occurred on the surface of Titan, in the bodies of liquid water which episodically may form on Titan's surface from meteoritic and cometary impacts. The formation of biologically interesting compounds may also occur in the deep water ocean, from the hydrolysis of complex organic material included in the chrondritic matter accreted during the formation of Titan. The possible emergence and persistence of Life on Titan 1 All ingredients which seems necessary for Life are present on Titan : • liquid water : permanently as a deep sub-surface ocean, and even episodically on the surface, • organic matter : in the internal structure, from chondritic materials, and in the atmosphere and on the surface, from the atmospheric organic chemistry • and energy : in the atmosphere (solar UV photons, energetic electrons from Saturn magnetosphere and cosmic rays) and, probably, in the environment of the sub-surface ocean (radioactive nuclei in the deep interior and tidal energy dissipation) as also supported by the likely presence of cryovolcanism on the surface Thus, it cannot be excluded that life may have emerged on or in Titan. In spite of the extreme conditions in this environment life may have been able to adapt and to persist. Many data are still expected from the Cassini-Huygens mission and future astrobiological exploration mission of Titan are now under consideration. Nevertheless, Titan already looks like another word, with an active prebiotic-like chemistry, but in the absence of permanent liquid water, on the surface: a natural laboratory for prebiotic-like chemistry. References. Fortes, A.D. (2000), `Exobiological implications of a possible ammonia-water ocean inside Titan', Icarus 146, 444-452 Raulin, F. (2005), `Exo-Astrobiological Aspects of Europa and Titan: From Observations to Speculations', Space Science Review 116 (1-2), 471-496. Nature, (2005), `The Huygens probe on Titan', 8 News & Views, Articles and Letters 438, 756-802 Schulze-Makuch, D., and Grinspoon D.H. (2005), `Biologically enhanced energy and carbon cycling on Titan?',Astrobiology 5, 560-567. 2

  2. Crystallization thermometers for zircon and rutile

    Microsoft Academic Search

    E. B. Watson; D. A. Wark; J. B. Thomas

    2006-01-01

    Zircon and rutile are common accessory minerals whose essential structural constituents, Zr, Ti, and Si can replace one another to a limited extent. Here we present the combined results of high pressure–temperature experiments and analyses of natural zircons and rutile crystals that reveal systematic changes with temperature in the uptake of Ti in zircon and Zr in rutile. Detailed calibrations

  3. Titan's organic chemistry

    NASA Astrophysics Data System (ADS)

    Sagan, C.; Thompson, W. R.; Khare, B. N.

    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.

  4. Titan's thick haze layer

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Titan's thick haze layer is shown in this enhanced Voyager 1 image taken Nov. 12, 1980 at a distance of 435,000 kilometers (270,000 miles). Voyager images of Saturn's largest moon show Titan completely enveloped by haze that merges with a darker 'hood' or cloud layer over the north pole. Such a mantle is not present at the south pole. At Voyager's closest approach to Titan on Nov. 11, 1980, spacecraft instruments found that the moon has a substantial atmosphere, far denser than that of Mars and possibly denser than Earth's. The Voyager Project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

  5. 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.

  6. The Astrobiology of Titan

    NASA Astrophysics Data System (ADS)

    Lunine, J. I.

    2014-02-01

    Titan is a target of astrobiological interest because of its thick atmosphere, ample organics inventory, large size and presence of water ice and rock. Multiple habitable environments, or prebiotically interesting environments, may exist.

  7. The greenhouse of Titan.

    NASA Technical Reports Server (NTRS)

    Sagan, C.

    1973-01-01

    Analysis of non-gray radiative equilibrium and gray convective equilibrium on Titan suggests that a massive molecular-hydrogen greenhouse effect may be responsible for the disagreement between the observed IR temperatures and the equilibrium temperature of an atmosphereless Titan. Calculations of convection indicate a probable minimum optical depth of 14 which corresponds to a molecular hydrogen shell of substantial thickness with total pressures of about 0.1 bar. It is suggested that there is an equilibrium between outgassing and blow-off on the one hand and accretion from the protons trapped in a hypothetical Saturnian magnetic field on the other, in the present atmosphere of Titan. It is believed that an outgassing equivalent to the volatilization of a few kilometers of subsurface ice is required to maintain the present blow-off rate without compensation for all geological time. The presence of an extensive hydrogen corona around Titan is postulated, with surface temperatures up to 200 K.

  8. Titan Casts Revealing Shadow

    NASA Astrophysics Data System (ADS)

    2004-05-01

    A rare celestial event was captured by NASA's Chandra X-ray Observatory as Titan -- Saturn's largest moon and the only moon in the Solar System with a thick atmosphere -- crossed in front of the X-ray bright Crab Nebula. The X-ray shadow cast by Titan allowed astronomers to make the first X-ray measurement of the extent of its atmosphere. On January 5, 2003, Titan transited the Crab Nebula, the remnant of a supernova explosion that was observed to occur in the year 1054. Although Saturn and Titan pass within a few degrees of the Crab Nebula every 30 years, they rarely pass directly in front of it. "This may have been the first transit of the Crab Nebula by Titan since the birth of the Crab Nebula," said Koji Mori of Pennsylvania State University in University Park, and lead author on an Astrophysical Journal paper describing these results. "The next similar conjunction will take place in the year 2267, so this was truly a once in a lifetime event." Animation of Titan's Shadow on Crab Nebula Animation of Titan's Shadow on Crab Nebula Chandra's observation revealed that the diameter of the X-ray shadow cast by Titan was larger than the diameter of its solid surface. The difference in diameters gives a measurement of about 550 miles (880 kilometers) for the height of the X-ray absorbing region of Titan's atmosphere. The extent of the upper atmosphere is consistent with, or slightly (10-15%) larger, than that implied by Voyager I observations made at radio, infrared, and ultraviolet wavelengths in 1980. "Saturn was about 5% closer to the Sun in 2003, so increased solar heating of Titan may account for some of this atmospheric expansion," said Hiroshi Tsunemi of Osaka University in Japan, one of the coauthors on the paper. The X-ray brightness and extent of the Crab Nebula made it possible to study the tiny X-ray shadow cast by Titan during its transit. By using Chandra to precisely track Titan's position, astronomers were able to measure a shadow one arcsecond in diameter, which corresponds to the size of a dime as viewed from about two and a half miles. Illustration of Crab, Titan's Shadow and Chandra Illustration of Crab, Titan's Shadow and Chandra Unlike almost all of Chandra's images which are made by focusing X-ray emission from cosmic sources, Titan's X-ray shadow image was produced in a manner similar to a medical X-ray. That is, an X-ray source (the Crab Nebula) is used to make a shadow image (Titan and its atmosphere) that is recorded on film (Chandra's ACIS detector). Titan's atmosphere, which is about 95% nitrogen and 5% methane, has a pressure near the surface that is one and a half times the Earth's sea level pressure. Voyager I spacecraft measured the structure of Titan's atmosphere at heights below about 300 miles (500 kilometers), and above 600 miles (1000 kilometers). Until the Chandra observations, however, no measurements existed at heights in the range between 300 and 600 miles. Understanding the extent of Titan's atmosphere is important for the planners of the Cassini-Huygens mission. The Cassini-Huygens spacecraft will reach Saturn in July of this year to begin a four-year tour of Saturn, its rings and its moons. The tour will include close flybys of Titan that will take Cassini as close as 600 miles, and the launching of the Huygens probe that will land on Titan's surface. Chandra's X-ray Shadow of Titan Chandra's X-ray Shadow of Titan "If Titan's atmosphere has really expanded, the trajectory may have to be changed." said Tsunemi. The paper on these results has been accepted and is expected to appear in a June 2004 issue of The Astrophysical Journal. Other members of the research team were Haroyoski Katayama (Osaka University), David Burrows and Gordon Garmine (Penn State University), and Albert Metzger (JPL). Chandra observed Titan from 9:04 to 18:46 UT on January 5, 2003, using its Advanced CCD Imaging Spectrometer instrument. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters,

  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. Titan Photochemistry 1974- 2014

    NASA Astrophysics Data System (ADS)

    Strobel, D. F.

    2014-04-01

    It has been 40 years since I published the first paper on Titan photochemistry (Strobel, Icarus, 21, 466- 470, 1974) and pointed out the fundamental difference between the giant planets and Titan. Namely, that unlike the giant planets, light constituents, principally H and H2, can readily escape from the atmosphere of Titan leading to irreversible loss of CH4 from photolysis and a requirement for replenishment by outgassing to maintain a stable presence in the atmosphere on timescales exceeding 50 MY. Since then we have had the Voyager Mission and now the on-going Cassini Huygens Mission plus ground-based telescope observations all contributing to our knowledge about the fascinating photochemical processes on Titan. The talk will finish with an analysis of where we are in our understanding and the outstanding issues that still need to be resolved.

  11. Electric switching in bistable ferrite-piezoelectric microwave resonator

    NASA Astrophysics Data System (ADS)

    Ustinov, A. B.; Fetisov, Yu. K.; Lebedev, S. V.; Srinivasan, G.

    2010-02-01

    The electric switching in a bistable ferrite-piezoelectric microwave resonator comprising a mechanically coupled yttrium iron garnet (YIG) ferrite film on a lead zirconate titanate (PZT) piezoelectric plate has been studied. The YIG/PZT resonator exhibits switching between stable states with small and large reflectance for a time on the order of a microsecond.

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

    Microsoft Academic Search

    Leslie J. Bowen; Kenneth W. French

    1992-01-01

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

  13. Fabrication of high frequency spherically shaped ceramic transducers

    Microsoft Academic Search

    Geoffrey R. Lockwood; Daniel H. Turnbull; F. Stuart Foster

    1994-01-01

    Difficulty in obtaining well focused efficient ultrasound transducers has limited the development of new high frequency applications of B-mode imaging. This paper describes a method for fabricating high frequency (53 MHz) spherically focused lead zirconate titanate (PZT) transducers. A transducer is fabricated by bonding a malleable backing layer onto a thin plate of PZT and then pressing the plate into

  14. Spectral Characteristics of Titan's Surface

    NASA Astrophysics Data System (ADS)

    Griffith, Caitlin A.; Turner, Jake D.; Penteado, Paulo; Khamsi, Tymon B.; Soderblom, Jason M.

    2014-11-01

    Cassini/Huygens and ground-based measurements of Titan reveal an eroded surface, with lakes, dunes, and sinuous washes. These features, coupled with measurements of clouds and rain, indicate the transfer of methane between Titan’s surface and atmosphere. The presence of methane-damp lowlands suggests further that the atmospheric methane (which is continually depleted through photolysis) may be supplied by sub-surface reservoirs. The byproducts of methane photolysis condense onto the surface, leaving layers of organic sediments that record Titan’s past atmospheres.Thus knowledge of the source and history of Titan's atmosphere requires measurements of the large scale compositional makeup of Titan's surface, which is shrouded by a thick and hazy atmosphere. Towards this goal, we analyzed roughly 100,000 spectra recorded by Cassini’s Visual and Infrared Mapping Spectrometer (VIMS). Our study is confined to the latitude region (20S—20N) surrounding the landing site of the Huygens probe (at 10S, 192W), which supplied only measurement of the vertical profiles of the methane abundance and haze scattering characteristics. VIMS near-IR spectral images indicate subtle latitudinal and temporal variations in the haze characteristics in the tropics. We constrain these small changes with full radiative transfer analyses of each of the thousands of VIMS spectra, which were recorded of different terrains and at different lighting conditions. The resulting models of Titan’s atmosphere as a function of latitude and year indicate the seasonal migration of Titan’s tropical haze and enable the derivation of Titan’s surface albedo at 8 near-IR wavelength regions where Titan’s atmosphere is transparent enough to allow visibility to the surface. The resultant maps of Titan’s surface indicate a number of terrain types with distinct spectral characteristics that are suggestive of atmospheric and surficial processes, including the deposition of organic material, erosion of sediments and potential sources of methane.

  15. Flexible PZT thin film tactile sensor for biomedical monitoring.

    PubMed

    Tseng, Hong-Jie; Tian, Wei-Cheng; Wu, Wen-Jong

    2013-01-01

    This paper presents the development of tactile sensors using the sol-gel process to deposit a PZT thin-film from 250 nm to 1 ?m on a flexible stainless steel substrate. The PZT thin-film tactile sensor can be used to measure human pulses from several areas, including carotid, brachial, finger, ankle, radial artery, and the apical region. Flexible PZT tactile sensors can overcome the diverse topology of various human regions and sense the corresponding signals from human bodies. The measured arterial pulse waveform can be used to diagnose hypertension and cardiac failure in patients. The proposed sensors have several advantages, such as flexibility, reliability, high strain, low cost, simple fabrication, and low temperature processing. The PZT thin-film deposition process includes a pyrolysis process at 150 °C/500 °C for 10/5 min, followed by an annealing process at 650 °C for 10 min. Finally, the consistent pulse wave velocity (PWV) was demonstrated based on human pulse measurements from apical to radial, brachial to radial, and radial to ankle. It is characterized that the sensitivity of our PZT-based tactile sensor was approximately 0.798 mV/g. PMID:23698262

  16. Flexible PZT Thin Film Tactile Sensor for Biomedical Monitoring

    PubMed Central

    Tseng, Hong-Jie; Tian, Wei-Cheng; Wu, Wen-Jong

    2013-01-01

    This paper presents the development of tactile sensors using the sol-gel process to deposit a PZT thin-film from 250 nm to 1 ?m on a flexible stainless steel substrate. The PZT thin-film tactile sensor can be used to measure human pulses from several areas, including carotid, brachial, finger, ankle, radial artery, and the apical region. Flexible PZT tactile sensors can overcome the diverse topology of various human regions and sense the corresponding signals from human bodies. The measured arterial pulse waveform can be used to diagnose hypertension and cardiac failure in patients. The proposed sensors have several advantages, such as flexibility, reliability, high strain, low cost, simple fabrication, and low temperature processing. The PZT thin-film deposition process includes a pyrolysis process at 150 °C/500 °C for 10/5 min, followed by an annealing process at 650 °C for 10 min. Finally, the consistent pulse wave velocity (PWV) was demonstrated based on human pulse measurements from apical to radial, brachial to radial, and radial to ankle. It is characterized that the sensitivity of our PZT-based tactile sensor was approximately 0.798 mV/g. PMID:23698262

  17. Optical properties of sol-gel-derived PZT thin films

    NASA Astrophysics Data System (ADS)

    Teowee, Gimtong T.; Boulton, J. M.; Motakef, Sharnaz; Uhlmann, Donald R.; Zelinski, Brian J.; Zanoni, Raymond; Moon, M.

    1992-12-01

    A series of sol-gel derived PT-based films, including PT, PZ, PZT, PLT, PLZ and PLZT, was prepared on platinized Si, fused SiO2 and Corning 7059 substrates. These films were fired at 400 - 700 C for 30 mins. The phase assembly and development were dependent on the precursor chemistries, processing and choice of substrates. The presence of Zr impacted significantly on the crystallization behavior, PbO loss and cracking behavior of the films. Crystallization was severely retarded, especially in Zr-containing PZT films when deposited on amorphous substrates compared to crystalline Pt substrates. Amorphous and crystalline PZT films can be utilized for passive and active optical applications. Waveguiding was achieved in an amorphous PZT 53/47 and a crystalline PLT 28 films and gave attenuation losses of 1.0 and 1.4 dB/cm respectively which represent the lowest values reported to date. The optical properties of the films were investigated using ellipsometry, UV-VIS transmission spectroscopy and waveguide loss measurements. Depending on composition and processing conditions, PZT films (2500 A thick) with refractive indices of 1.60 to 2.33 and absorption edges of 2900 - 3100 A can be obtained. It was ascertained that the resulting interfacial reaction layers between the films and substrates affected considerably the optical properties of thinner films (< 2000 A).

  18. 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.

  19. Barium titanate nanocomposite capacitor FY09 year end report.

    SciTech Connect

    Stevens, Tyler E.; DiAntonio, Christopher Brian; Yang, Pin; Chavez, Tom P.; Winter, Michael R.; Monson, Todd C.; Roesler, Alexander William; Fellows, Benjamin D.

    2009-11-01

    This late start RTBF project started the development of barium titanate (BTO)/glass nanocomposite capacitors for future and emerging energy storage applications. The long term goal of this work is to decrease the size, weight, and cost of ceramic capacitors while increasing their reliability. Ceramic-based nanocomposites have the potential to yield materials with enhanced permittivity, breakdown strength (BDS), and reduced strain, which can increase the energy density of capacitors and increase their shot life. Composites of BTO in glass will limit grain growth during device fabrication (preserving nanoparticle grain size and enhanced properties), resulting in devices with improved density, permittivity, BDS, and shot life. BTO will eliminate the issues associated with Pb toxicity and volatility as well as the variation in energy storage vs. temperature of PZT based devices. During the last six months of FY09 this work focused on developing syntheses for BTO nanoparticles and firing profiles for sintering BTO/glass composite capacitors.

  20. Titan's astrobiology: some new data

    Microsoft Academic Search

    Francois Raulin; Patrice Coll; Arnaud Buch; Megane Cloix; Yuan Yong Guan; Murielle Jerome; Olivier Poch; Sandra I. Ramirez; Cyril Szopa; Hervé Cottin

    2010-01-01

    The Cassini-Huygens observations of Titan have strongly strengthened its astrobiological impor-tance, clearly showing that Titan is one of the key planetary bodies for astrobiological studies. Indeed the Cassini-Huygens data show that there are many similarities which can be found when comparing Titan and the early Earth, in spite of much lower temperatures for Titan. One of these similarities is the

  1. Active vibration control of a PZT actuated suspension in hard disk drives

    Microsoft Academic Search

    Yunfeng Li; Roberto Horowitz

    2002-01-01

    This paper presents the design and testing results of active vibration control for a PZT actuated suspension. One PZT strip on the suspension is used as a vibration sensor, and the other as an actuator. A state space model for the PZT actuated suspension was established based on curve-fitted transfer functions, and a feedback damping controller was designed, using the

  2. STUDY OF PROTON EXCHANGE MEMBRANE FUEL CELLS (PZT-PEMFCS) WITH NOZZLE AND DIFFUSER

    Microsoft Academic Search

    Hsiao-Kang Ma; Shih-Han Huang; Ya-Ting Cheng; Chrung Guang Hou

    2009-01-01

    Previous theoretical studies have shown that piezoelectric proton exchange membrane fuel cells (PZT-PEMFCs) might solve water flooding problems and increase cell performance. The innovative design of PZT-PEMFCs results in more oxygen being compressed into the catalyst layer. This enhances the electrochemical reaction and the current density, especially at a high PZT vibration frequency (64 Hz). In this investigation, a single,

  3. Optical characterization of ferroelectric PZT thin films by variable angle spectroscopic ellipsometry

    NASA Astrophysics Data System (ADS)

    Rahman, Md. Shafiqur; Garcia, Carlos D.; Bhalla, Amar; Guo, Ruyan

    2014-09-01

    Ferroelectric thin films are used as high dielectric constant capacitors, infrared detectors, piezoelectric transducers, optical modulators, optical waveguides, and nonvolatile memory chips for dynamic random access memory (DRAM) etc. While ferroelectric and dielectric properties of these films have been extensively investigated, their optical properties have been comparatively less studied and of limited use in quantitative evaluation of multilayer thin films. In this work we explored the variable angle spectroscopic ellipsometry (VASE) technique for its effectiveness in physical property characterization. The VASE combined with its computer modeling tool enables nondestructive, nonintrusive, and contactless optical means for optical characterization. Crystalline Lead Zirconium Titanate PbZr0.52Ti0.48O3 (PZT) thin films, fabricated on SrTiO3 layer atop of Si substrates, were characterized using VASE (J.A. Woollam; Lincoln, NE, USA) by determining the ellipsometric parameters ? and ? as a function of wavelengths (200-1000 nm) and incident angles (65°, 70°,75°) at room temperature. A physical representation of the multilayer system was constructed by a six layer model (analysis software WVASE32, J.A. Woollam) through a step-by-step method. Other physical properties characterized by several well-known techniques on structure, morphology and topographical features correspond well with the models developed using VASE alone. The technique and the methodology developed have shown promises in identifying the respective thickness and optical properties of multilayer thin film system, with limited input of processing or composition information.

  4. Characteristics of zircon suitable for REE extraction

    NASA Astrophysics Data System (ADS)

    Watanabe, Y.; Hoshino, M.

    2011-12-01

    Zircons (ZrSiO4) from Naegi and Ohro granitic pegmatites, Japan and from Saigon alkaline basalt, Vietnam, were mineralogically characterized by inductively couples plasma mass spectrometry (ICP-MS), electron-microprobe analysis (EMPA), X-ray powder diffraction, micro-Raman spectroscopy and leaching experiment. The powder XRD and Raman spectra analyses show that the degree of crystallinity decreases from Saigon, to Ohro and Naegi zircons. Quantitative analytical results by the EMPA indicate that the Naegi and Ohro zircon samples contain a large amount of REE2O3, while REE contents in Saigon zircon are below detection limit. The leaching experiments for the present zircons under the condition of a solvent 1M-HCl, at a room temperature to 250 °C and retention time of 30h resulted in about 100 %, 50 % and 1 % recoveries of REE from the Naegi, Ohro and Saigon zircons, respectively. Leaching experiments for the Naegi zircon under the condition of a solvent 1N-HCl, heating temperature of 50 °C, 100 °C, 150 °C and 200 °C, and retention time 30h, showed that a significant amount of REE was leached out at a temperature above 150 °C. However, the leaching experiments of the Naegi and Ohro zircons at room temperature (about 25 °C) show that REE were hard to be leached. These results indicates that both low crystallinity of zircon and higher leaching temperature are requisite for effective leaching of REE from zircon.

  5. The methane cycle on Titan

    Microsoft Academic Search

    Jonathan I. Lunine; Sushil K. Atreya

    2008-01-01

    Saturn's moon Titan is the second largest natural satellite in the solar system, and the only one that possesses a substantial atmosphere. With a surface temperature of 93.7 K at the equator, Titan's water is almost completely frozen out of the atmosphere; water ice comprises between 35% and 45% of the mass of Titan depending on the interior model. But

  6. 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

  7. Zircon Saturation Re-Revisited

    NASA Astrophysics Data System (ADS)

    Boehnke, P.; Trail, D.; Schmitt, A. K.; Watson, E. B.; Harrison, M.

    2011-12-01

    Zircon saturation in silicate melts has been utilized for magma thermometry and predicting the survival of zircon xenocrysts in crustal melts for nearly 30 years. The original calibration, which assumed only compositional (M = [2Ca+Na+K]/[AlxSi]) and temperature controls, was bolstered by subsequent experimental investigations and thermometry of volcanic rocks and glasses. These latter studies, while confirming the general predictions of the model, suggested that other environmental parameters (e.g., pressure, H 2O, halogens, [Fe], oxygen fugacity, etc.) might have second-order effects. Given the tremendous advances in micro-analytical capabilities over the intervening three decades, we have returned to this question with a view to obtaining a refined zircon solubility calibration as a function of P, T, [H2O] and FM (= [Na+K+2(Ca+Mg+Fe)]/[AlxSi]). Detailed SEM imaging of the original low-temperature crystallization experiments (1.2-2.1 kbar) revealed limitations of this approach and we chose instead to use a new experimental design in which shattered Mud Tank zircon is infiltrated by melts of selected composition and water contents. 10 kbar hydrothermal experiments (925o and 850oC) were run for sufficiently long durations (2 to 3 days) to ensure microscale diffusive equilibration of Zr released by zircon dissolution into the intercrystalline melt pools. Sectioned run products were analyzed by SIMS ion imaging of selected areas where glass is exposed in close proximity to or surrounded by Mud Tank zircon fragments. Ion imaging has the advantage of permitting high spatial resolution (3 ?m) analysis of the glasses allowing assessment of Zr equilibration. Using synthetic glass standards, we found [Zr] in anhydrous glasses to be enhanced by ca. 20% relative to hydrous (at 6 wt.% H2O). Our new experiments and re-analysis of the earlier glasses broadly reproduce the original calibration, albeit with substantially enhanced (factor of five) precision compared to the original EMPA analyses. Thus it appears that no significant pressure effect exists up to at least 10 kbar. Ongoing work will expand the pressure range beyond this limit and explore a greater compositional space than previously constrained.

  8. 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.

  9. An improved star catalogue for Ond?ejov PZT

    NASA Astrophysics Data System (ADS)

    Ron, C.; Vondrák, J.

    The observations of 305 stars made in the period from 1973 to 2002 with the PZT at Ond?ejov Observatory were combined with the positions of the same stars in the catalogues AGK2, AGK3 and HIPPARCOS in order to obtain their mean positions and proper motions. The modified algorithm of Vondrák (1980) and Ron & Vondrák (1985) has been used for the adjustment. More than 77000 individual star transits on 2561 nights have been observed within the period in question with the PZT.

  10. Impact craters on Titan

    USGS Publications Warehouse

    Wood, C.A.; Lorenz, R.; Kirk, R.; Lopes, R.; Mitchell, K.; Stofan, E.

    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. ?? 2009 Elsevier Inc.

  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. Aboard the Titanic

    NSDL National Science Digital Library

    Mrs. Maahs

    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. Introduction: You are going to be a passenger on board the RMS Titanic. You boarded the ship and set sail expecting the experience of a lifetime upon the Ship of Dreams, but what will happen next? In this project we will be exploring how the ship was structured, what activities were ...

  13. 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.

  14. Metallic lead nanospheres discovered in ancient zircons.

    PubMed

    Kusiak, Monika A; Dunkley, Daniel J; Wirth, Richard; Whitehouse, Martin J; Wilde, Simon A; Marquardt, Katharina

    2015-04-21

    Zircon (ZrSiO4) is the most commonly used geochronometer, preserving age and geochemical information through a wide range of geological processes. However, zircon U-Pb geochronology can be affected by redistribution of radiogenic Pb, which is incompatible in the crystal structure. This phenomenon is particularly common in zircon that has experienced ultra-high temperature metamorphism, where ion imaging has revealed submicrometer domains that are sufficiently heterogeneously distributed to severely perturb ages, in some cases yielding apparent Hadean (>4 Ga) ages from younger zircons. Documenting the composition and mineralogy of these Pb-enriched domains is essential for understanding the processes of Pb redistribution in zircon and its effects on geochronology. Using high-resolution scanning transmission electron microscopy, we show that Pb-rich domains previously identified in zircons from East Antarctic granulites are 5-30 nm nanospheres of metallic Pb. They are randomly distributed with respect to zircon crystallinity, and their association with a Ti- and Al-rich silica melt suggests that they represent melt inclusions generated during ultra-high temperature metamorphism. Metallic Pb is exceedingly rare in nature and previously has not been reported in association with high-grade metamorphism. Formation of these metallic nanospheres within annealed zircon effectively halts the loss of radiogenic Pb from zircon. Both the redistribution and phase separation of radiogenic Pb in this manner can compromise the precision and accuracy of U-Pb ages obtained by high spatial resolution methods. PMID:25848043

  15. Monolithically Integrated Piezomems SP2T Switch and Contour-Mode Filters

    Microsoft Academic Search

    J. S. Pulskamp; D. C. Judy; R. G. Polcawich; R. Kaul; H. Chandrahalim; S. A. Bhave

    2009-01-01

    This paper provides the first experimental demonstration of monolithically integrated piezoelectric MEMS RF switches with contour mode filters. Lead zirconate titanate (PZT) thin films are utilized to enable both low-voltage switch operation and filter tunability. This research leverages previous work using PZT actuators for low-voltage, wide-band switches and PZT transduced silicon resonators. The two device technologies are combined using a

  16. Characterization of nanostructured ceramics prepared by both high energy ball milling and fast firing sintering processes

    Microsoft Academic Search

    Y. Leyet; F. Guerrero; E. Pérez-Delfín; J. Pérez de la Cruz; J. A. Eiras

    2011-01-01

    High-energy ball milling technique was successfully applied to calcinated lead zirconate titanate (PZT 60\\/40) powders. After 20?h of ball milling, large PZT particles were completely broken down, reducing its initial size in three orders of magnitude. Experimental results show a huge sinterability enhancement of the PZT powders by using this technique, achieving its maximum sintering rate at ?800°C. Relatively low

  17. Characterization of nanostructured ceramics prepared by both high energy ball milling and fast firing sintering processes

    Microsoft Academic Search

    Y. Leyet; F. Guerrero; E. Pérez-Delfín; J. Pérez de la Cruz; J. A. Eiras

    2012-01-01

    High-energy ball milling technique was successfully applied to calcinated lead zirconate titanate (PZT 60\\/40) powders. After 20?h of ball milling, large PZT particles were completely broken down, reducing its initial size in three orders of magnitude. Experimental results show a huge sinterability enhancement of the PZT powders by using this technique, achieving its maximum sintering rate at ?800°C. Relatively low

  18. Interpenetrating PZT\\/polymer composites for hydrophones: Models and experiments

    Microsoft Academic Search

    Hudai Kara; Andrew Perry; Ron Stevens; Chris R. Bowen

    2002-01-01

    PZT\\/Polymer composites with various polymer content and connectivity patterns have been manufactured for hydrophone applications. The composites were investigated in terms of permittivity, hydrostatic charge (dh), voltage (gh) coefficients and hydrostatic figure of merit (dhgh) with varying polymer content. The results are compared with analytical and numerical models. The composite with 80% polymer content showed an improved hydrostatic figure of

  19. Structural and Ferroelectric Characterization of PZT Thin Films

    NASA Astrophysics Data System (ADS)

    Yang, Ying; Chen, Zhiming; Zhao, Gaoyang; Zhang, Weihua

    Pb(ZrxTi1-x)O3 (PZT) films were prepared on the ITO coated glass plates in sol-gel dip-coating process and post-annealing at different temperatures. The structural properties of the films were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It is shown that the PZT ferroelectric thin films with (110) preferential orientation and well-crystallized perovskite structure can be obtained after annealing at 680°C for 30 minutes. The P-E hysteresis loops were measured by the Sawyer-Tower test system with a compensation resistor at room temperature. Values of the remanent polarization (Pr) and the coercive electric field (Ec) are 19.36•C/cm2 and 95 kV/cm, respectively, for the prepared PZT thin films. The relative dielectric constant ?r and the dissipation factor tg• of the PZT thin films are equal to 639 and 0.23, respectively, which were measured in a LCR meter.

  20. Titan Pride Center Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Pride Center Student Engagement Report FY 2012-2013 Mission Statement The vision of the Titan Pride Center is to instill Titan Pride into all Cal State Fullerton students by connecting them a Titan. Program Overview The core services of the Titan Pride Center include being a campus history

  1. Temperature dependent XAFS studies of local atomic structure of the perovskite-type zirconates

    SciTech Connect

    Vedrinskii, R. V.; Lemeshko, M. P.; Novakovich, A. A. [Institute of Physics, Rostov State University, 194 Stachky Avenue, Rostov-on-Don 344090 (Russian Federation); Nazarenko, E. S. [Institute of Physics, Rostov State University, 194 Stachky Avenue, Rostov-on-Don 344090 (Russian Federation); Laboratoire de Cristallographie, CNRS, l'Universite Joseph Fourier, 166 Boite Postale, F-38042 Grenoble Cedex 9 (France); Nassif, V. [CEA/Grenoble, DRFMC/SP2M/NRS, F-38054 Grenoble Cedex 9 (France); BM30b CRG-FAME, European Synchrotron Radiation Facility, F-38043 Grenoble Cedex 9 (France); Proux, O. [Laboratoire de Geophysique Interne et Tectonophysique, UMR CNRS, Universite Joseph Fourier, F-38400 Saint-Martin-D'Heres (France); BM30b CRG-FAME, European Synchrotron Radiation Facility, F-38043 Grenoble Cedex 9 (France); Joly, Y. [Laboratoire de Cristallographie, CNRS, l'Universite Joseph Fourier, 166 Boite Postale, F-38042 Grenoble Cedex 9 (France)

    2006-04-01

    Temperature dependent preedge and extended x-ray absorption fine structure measurements at the Zr K edge for the perovskite-type zirconates PbZr{sub 0.515}Ti{sub 0.485}O{sub 3} (PZT), PbZrO{sub 3} (PZ), and BaZrO{sub 3} are performed. To carry out a more accurate study of the weak reconstruction of the local atomic structure we employed a combination of two techniques: (i) analysis of the preedge fine structure, and (ii) analysis of the Fourier transform of the difference between {chi}(k) functions obtained at different temperatures. A detailed investigation of local atomic structure in the cubic phase for all the crystals is also performed. It is shown that neither the displacive nor the order-disorder model can describe correctly the changes of local atomic structure during phase transitions in PZ and PZT. A spherical model describing the local atomic structure of perovskite-type crystals suffering structural phase transitions is proposed.

  2. Exobiology on Titan

    Microsoft Academic Search

    F. Raulin; P. Bruston; P. Coll; D. Coscia; M. C. Gazeau; L. Guez; E. Vanssay

    1995-01-01

    With a dense N2-CH4 atmosphere rich in organics, both in gas and aerosol phases, and with the possible presence of hydrocarbons oceans on its surface, Titan, the largest satellite of Saturn, appears as a natural laboratory to study chemical evolution toward complex organic systems, in a planetary environment and over a long time scale. Thanks to many analogies with planet

  3. 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

  4. 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

  5. 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

  6. 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

  7. Thermal effects on domain orientation of tetragonal piezoelectrics

    Microsoft Academic Search

    Wonyoung Chang

    2007-01-01

    Thermal effects on electrical poling or mechanical grinding induced texture in tetragonal lead zirconate titanate (PZT) and lead titanate (PT) have been investigated using ex situ and in situ X-ray diffraction (XRD) with an area detector. According to previous results using ex situ XRD, domain configurations of poled samples after heat-treatment at or higher than the Curie temperature (TC) are

  8. 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

  9. Advances in Zircon Geochronology: Understanding Zircon Growth and Modification During Metamorphism

    NASA Astrophysics Data System (ADS)

    Möller, A.

    2004-05-01

    The interpretation of zircon ages has long relied on the qualitative interpretation of external shape and internal zoning patterns. Common assumptions for metamorphic zircons were that they date the peak of metamorphism, have low Th/U, and that granulite facies zircon is multifaceted. Whereas these may be useful rules of thumb, progress is now made in several areas by in-situ analyses e.g. i) balancing zircon forming reactions by in-situ trace element analyses of Zr-bearing minerals (providing evidence for the potential of prograde as well as retrograde zircon growth), iii) linking metamorphic textures and thermobarometry to U-Pb geochronology results, iii) linking zircon geochemistry to different growth mechanisms, and processes of zircon modification (recognising that low Th/U in zircon requires presence of a fluid phase or a mineral competing for Th, e.g. monazite). Modification mechanisms other than the classic hypotheses (volume diffusion, metamictisation) can be proposed to account for 'resetting' of zircon U-Pb ages: e.g. fluid-related or fluid-absent recrystallization, lattice strain reduction by purging of trace elements. Examples from high grade metamorphic areas in Norway, Brazil and Uganda are used to illustrate that in-situ analysis, relating inclusion textures to trace elements in zircon help provide constraints on the P-T-t evolution. Tracking geochemical characteristics through time provides constraints on the mechanisms of zircon growth or modification. Multifaceted, equant and sector-zoned zircon for example characteristically crystallizes from anatectic melts. Whether these are prograde, peak or retrograde melts depends on the particular P-T history of the host rock. Solid-state recrystallized zircon typically inherits the Th/U characteristics of its parent. It can be shown by textural as well as trace element evidence that without dissolution or recrystallization of pre-existing zircon, metamorphic reactions consuming Zr-bearing minerals may trigger new zircon growth (e.g. garnet, ilmenite, rutile). Breakdown of garnet for example may produce high-Y zircon or trigger xenotime growth. Rare earth element patterns can be used to test growth of zircon in equilibrium with important metamorphic minerals (garnet, orthopyroxene). Ultimately, whether zircon has the potential to record certain stages of the P-T history and how depends on the reaction history of a particular rock, its P-T path and its pre-metamorphic history (previous melting and melt-extraction may prevent new zircon growth).

  10. Modeling Zircon Saturation Within Simulated Impact Events

    NASA Astrophysics Data System (ADS)

    Wielicki, M. M.; Harrison, M.; Boehnke, P.; Schmitt, A. K.

    2011-12-01

    Knowledge of the impact flux in the early inner solar system is fundamental to understanding the near surface conditions on the terrestrial planets during this formative period. However the lack of preserved >2.0 Ga craters precludes direct sampling of such events over the first 55% of Earth history. We do, however, have preserved crustal materials in the form of detrital zircons with ages up to 4.38 Ga that can potentially act as environmental monitors. In order to interpret zircon growth features in terms of impact events, such as the Late Heavy Bombardment (LHB), we developed a zircon saturation model that estimates the zircon crystallization temperature spectrum and the fraction of Zr in the continental crust expected to be processed through impact melting. Such modeling results can then be compared to the crystallization temperature spectrum of detrital Hadean zircons to estimate the fraction that were impact-produced. Magmatic zircon growth during an impact event is controlled by ambient temperature, Zr content and composition of the target material, and impact energy. Impacts need to be sufficiently large to permit decompression melting of uplifted middle to upper crust (i.e., low energy bolides will not produce melt sheets and thus impact zircons). We modeled the LHB using the thermal model and hypothesized bolide flux of Abramov and Mojzsis (Nature 459, 419, 2009). Target compositions for modern and Archean crust were estimated from large geochemical databases and selected using a Monte Carlo process by which the full spectrum of compositions were randomly chosen. Model results for impact produced zircon from a target of Archean composition yield a zircon crystallization temperature distribution significantly higher than that observed for detrital Hadean zircons from Western Australia. We take this as evidence that impact produced zircons are not a significant source for this population. Modeled results from impacts on modern crust yield temperatures remarkably similar to Ti-in-zircon crystallization temperatures of recent large impact events (i.e., Morokweng, Manicouagan). Refinements of the model include: reduction of sampling bias in compositional databases and development of hypothetical crustal compositions to simulate Hadean crystallization temperatures. This model can be used as an analog to predict zircon abundance and crystallization temperature spectrum for other planetary bodies (i.e. Moon, Mars, Vesta) where surface compositions are known or estimated. When rocks are in hand, in the form of meteorites or from sample return missions, modeled results can be compared to extracted zircons to estimate the contribution of impacts and provide insights into ancient impact histories.

  11. 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.

  12. Dating metamorphism using zircons in metabasic rocks

    NASA Astrophysics Data System (ADS)

    Connelly, J. N.; McFarlane, C. R. M.

    2003-04-01

    Regional metamorphism typically occurs over time spans that exceed errors for U-Pb ages of zircon by an order of magnitude or more. As we attempt to refine our understanding of metamorphic excursions of rocks during tectonic events, our understanding of the reactions and processes that control isotopically derived ages become more critical. However, a range of variables affecting the formation and modification of these chronometric phases (rock and fluid compositions, cooling rates and specific PT geometries) complicate rigorous integration of geochronometric, petrogenetic, and geothermobarometric data to define meaningful PTt paths. Dating major metamorphic phases (GRT, CPX, PL, etc) offers the most direct link to the timing of specific mineral paragenesis or equilibria, but invalid assumptions regarding closure and initial equilibrium may yield misleading or spurious ages. Refining the use of conventionally employed minor chronometric phases will require a better understanding of their paragenetic relationship with major phases that are typically used to define PT conditions. Towards this end, metabasites may offer an under-utilized means to constrain the timing of reactions given: 1) their relatively simple major mineral paragenesis, 2) that primary zircon is nearly always absent, 3) the common occurrence of low-U metamorphic zircon, and 4) the robustness of these zircons through subsequent thermal events. Additionally, but not restricted to metabasites, high Pb-retention temperature(s) of pristine zircon ensures determining a reaction (rather than closure) age. To evaluate the utility of zircons in metabasites to define “metamorphic ages”, we present U-Pb zircon data from a range of geological settings. Of particular interest, metabasites from single outcrops may return independently robust but distinctly different ages. From this we infer that zircons form from different reactions at different times along the PT path, controlled by bulk composition and/or P(fluids). Furthermore, these ages are distinctly older than ages derived from Sm-Nd (GRT-TTN-CPX-AP) isochrons. We presume that zircon formation is linked to, and therefore dates, the first breakdown of pyroxene to lower temperature, hydrous phases, a reaction that liberates SiO2 and Zr. Formation of granulites directly from rocks with primary pyroxene may, therefore, preclude the formation of zircon during metamorphism. But once formed, zircon appears stable and isotopically robust through subsequent metamorphism. It is, therefore, not assured that zircons in metabasites will faithfully record all high temperature events. However, the potential to link zircon formation in metabasites directly to major phase reactions offers exciting prospects to examine metamorphic diachroneity across regionally metamorphosed terrains, date metamorphic reactions, and construct meaningful PTt paths.

  13. Titan's Eccentricity Tides

    NASA Astrophysics Data System (ADS)

    Iess, L.; Jacobson, R.; Ducci, M.; Stevenson, D. J.; Lunine, J. I.; Armstrong, J. W.; Asmar, S.; Racioppa, P.; Rappaport, N. J.; Tortora, P.

    2011-12-01

    The large eccentricity (e=0.03) of Titan's orbit causes significant variations in the tidal field from Saturn and induces periodic stresses in the satellite body at the orbital period (about 16 days). Peak-to-peak variations of the tidal field (from pericenter to apocenter) are about 18% (6e). If Titan hosts a liquid layer (such as an internal ocean), the gravity field would exhibit significant periodic variations. The response of the body to fast variations of the external, perturbing field is controlled by the Love numbers, defined for each spherical harmonic as the ratio between the perturbed and perturbing potential. For Titan the largest effect is by far on the quadrupole field, and the corresponding Love number is indicated by k2 (assumed to be identical for all degree 2 harmonics). Models of Titan's interior generally envisage a core made up of silicates, surrounded by a layer of high pressure ice, possibly a liquid water or water-ammonia ocean, and an ice-I outer shell, with variations associated with the dehydration state of the core or the presence of mixed rock-ice layers. Previous analysis of Titan's tidal response [1] shows that k2 depends crucially on the presence or absence of an internal ocean. k2 was found to vary from about 0.03 for a purely rocky interior to 0.48 for a rigid rocky core surrounded by an ocean and a thin (20 km) ice shell. A large k2 entails changes in the satellite's quadrupole coefficients by a few percent, enough to be detected by accurate range rate measurements of the Cassini spacecraft. So far, of the many Cassini's flybys of Titan, six were used for gravity measurements. During gravity flybys the spacecraft is tracked from the antennas of NASA's Deep Space Network using microwave links at X- and Ka-band frequencies. A state-of-the-art instrumentation enables range rate measurements accurate to 10-50 micron/s at integration times of 60 s. The first four flybys provided the static gravity field and the moment of inertia factor of the body[2]. In this previous analysis, tidal variations of the gravity field were neglected. Thanks to the availability of two additional flybys (on May 20, 2010 and Feb. 18, 2011) and the improvement of the data analysis tools, also the variable component of the gravity field could be estimated with good accuracy. In order to increase the confidence in the results, two independent analyses have been carried out, both resulting in very close and statistically indistinguishable values for k2. While the results are compatible (at the low end of k2) with interior models made up by a high viscosity core and a near-surface liquid water layer, the centroid of the k2 values requires additionally that some substantial fraction of the interior -ice mantle or core- be capable of significant deformations over time scales of the orbital period. References [1] Rappaport, N.J. et al., 2008. Can Cassini detect a subsurface ocean in Titan from gravity measurements?, Icarus, Vol. 194, No. 2. [2] Iess, L. et al., 2010. Gravity field, shape, and moment of inertia of Titan. Science 327, 1367-1369.

  14. RADAR Reveals Titan Topography

    NASA Technical Reports Server (NTRS)

    Kirk, R. L.; Callahan, P.; Seu, R.; Lorenz, R. D.; Paganelli, F.; Lopes, R.; Elachi, C.

    2005-01-01

    The Cassini Titan RADAR Mapper is a K(sub u)-band (13.78 GHz, lambda = 2.17 cm) linear polarized RADAR instrument capable of operating in synthetic aperture (SAR), scatterometer, altimeter and radiometer modes. During the first targeted flyby of Titan on 26 October, 2004 (referred to as Ta) observations were made in all modes. Evidence for topographic relief based on the Ta altimetry and SAR data are presented here. Additional SAR and altimetry observations are planned for the T3 encounter on 15 February, 2005, but have not been carried out at this writing. Results from the T3 encounter relevant to topography will be included in our presentation. Data obtained in the Ta encounter include a SAR image swath

  15. 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.

  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. NPR: Titanic Baby

    NSDL National Science Digital Library

    2002-01-01

    This Web site contains an audio file of a story broadcast on National Public Radio earlier this month. The broadcast relates the poignant story of a four-year effort to identify the exhumed body of a 13-month-old child who died in the Titanic disaster. A metal medallion buried with the body serendipitously preserved a bit of the wrist bone, from which forensic scientists could extract mitochondrial DNA and eventually find the child's living relatives.

  19. Landscape Evolution of Titan

    NASA Technical Reports Server (NTRS)

    Moore, Jeffrey

    2012-01-01

    Titan may have acquired its massive atmosphere relatively recently in solar system history. The warming sun may have been key to generating Titan's atmosphere over time, starting from a thin atmosphere with condensed surface volatiles like Triton, with increased luminosity releasing methane, and then large amounts of nitrogen (perhaps suddenly), into the atmosphere. This thick atmosphere, initially with much more methane than at present, resulted in global fluvial erosion that has over time retreated towards the poles with the removal of methane from the atmosphere. Basement rock, as manifested by bright, rough, ridges, scarps, crenulated blocks, or aligned massifs, mostly appears within 30 degrees of the equator. This landscape was intensely eroded by fluvial processes as evidenced by numerous valley systems, fan-like depositional features and regularly-spaced ridges (crenulated terrain). Much of this bedrock landscape, however, is mantled by dunes, suggesting that fluvial erosion no longer dominates in equatorial regions. High midlatitude regions on Titan exhibit dissected sedimentary plains at a number of localities, suggesting deposition (perhaps by sediment eroded from equatorial regions) followed by erosion. The polar regions are mainly dominated by deposits of fluvial and lacustrine sediment. Fluvial processes are active in polar areas as evidenced by alkane lakes and occasional cloud cover.

  20. Simulation of thick film PZT actuators with interdigitated electrodes

    NASA Astrophysics Data System (ADS)

    Zaki, Mohanad M.; Zähringer, Sandy; Schwesinger, Norbert

    2013-05-01

    This paper deals with the simulation of membrane actuators based on thick film piezoelectric ceramics with interdigitated electrodes using the finite element method. A modified piezoelectric coupling matrix is introduced to account for the piezoelectric non-linearity due to poling and actuation at high electric fields. Electrodes were fabricated on top of 250 ?m thick PZT substrates which were characterized. The experimental data verified the simulation results and proved the necessity of the modified coupling matrix.

  1. Solution Synthesis and Processing of PZT Materials for Neutron Generator Applications

    SciTech Connect

    Anderson, M.A.; Ewsuk, K.G.; Montoya, T.V.; Moore, R.H.; Sipola, D.L.; Tuttle, B.A.; Voigt, J.A.

    1998-12-01

    A new solution synthesis route has been developed for the preparation of lead-based ferroelectric materials (patent filed). The process produces controlled stoichiometry precursor powders by non-aqueous precipitation. For a given ferroelectric material to be prepared, a metal acetate/alkoxide solution containing constituent metal species in the appropriate ratio is mixed with an oxalic acid/n-propanol precipitant solution. An oxalate coprecipitate is instantly fonned upon mixing that quantitatively removes the metals from solution. Most of the process development was focused on the synthesis and processing of niobium-substituted lead zirconate titanate with a Zr-to-Ti ratio of 95:5 (PNZT 95/5) that has an application in neutron generator power supplies. The process was scaled to produce 1.6 kg of the PNZT 95/5 powder using either a sen-ii-batch or a continuous precipitation scheme. Several of the PNZT 95/5 powder lots were processed into ceramic slug form. The slugs in turn were processed into components and characterized. The physical properties and electrical performance (including explosive functional testing of the components met the requirements set for the neutron generator application. Also, it has been demonstrated that the process is highly reproducible with respect to the properties of the powders it produces and the properties of the ceramics prepared from its powders. The work described in this report was funded by Sandia's Laboratory Directed Research and Development Program.

  2. Development of monolithic PZT microstage for the application of ultra high-density data storage

    Microsoft Academic Search

    H. G. Xu; K. Okamoto; D. Y. Zhang; T. Ono; M. Esashi

    2005-01-01

    The paper presents the fabrication and characterizations of a compact PZT actuated microstage with multi degrees of freedom (DOFs). The entire device is fabricated in a symmetrical arrangement from a monolithic PZT plate of size 15×15×0.8 mm3. Displacement amplification mechanisms are integrated in the structure to increase the stroke of the PZT actuator. The performances of the displacement and the

  3. High frequency broadband PZT thick film ultrasonic transducers for medical imaging applications

    Microsoft Academic Search

    Q. Q. Zhang; F. T. Djuth; Q. F. Zhou; C. H. Hu; J. H. Cha; K. K. Shung

    2006-01-01

    A modified sol–gel method is used to prepare PZT thick film on Pt-coated silicon substrate. A new method of vacuum filling sol–gel precursor solution is introduced to improve film quality. The effects of the filling on PZT thick film structure and ferroelectric properties are discussed. The fabrication of a high frequency transducer with the PZT film as the actuating layer

  4. Ti-in-zircon thermometry: applications and limitations

    Microsoft Academic Search

    Bin Fu; F. Zeb Page; Aaron J. Cavosie; John Fournelle; Noriko T. Kita; Jade Star Lackey; Simon A. Wilde; John W. Valley

    2008-01-01

    The titanium concentrations of 484 zircons with U-Pb ages of ?1 Ma to 4.4 Ga were measured by ion microprobe. Samples come\\u000a from 45 different igneous rocks (365 zircons), as well as zircon megacrysts (84) from kimberlite, Early Archean detrital zircons\\u000a (32), and zircon reference materials (3). Samples were chosen to represent a large range of igneous rock compositions. Most\\u000a of the

  5. Titan after Cassini Huygens

    NASA Astrophysics Data System (ADS)

    Beauchamp, P. M.; Lunine, J.; Lebreton, J.; Coustenis, A.; Matson, D.; Reh, K.; Erd, C.

    2008-12-01

    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 then a muffled splash signals the beginning of the first floating exploration of an extraterrestrial sea-this one not of water but of liquid hydrocarbons. Meanwhile, thousands of miles away, a hot air balloon, a "montgolfiere," cruises 6 miles above sunnier terrain, imaging vistas of dunes, river channels, mountains and valleys carved in water ice, and probing the subsurface for vast quantities of "missing" methane and ethane that might be hidden within a porous icy crust. Balloon and floater return their data to a Titan Orbiter equipped to strip away Titan's mysteries with imaging, radar profiling, and atmospheric sampling, much more powerful and more complete than Cassini was capable of. This spacecraft, preparing to enter a circular orbit around Saturn's cloud-shrouded giant moon, has just completed a series of flybys of Enceladus, a tiny but active world with plumes that blow water and organics from the interior into space. Specialized instruments on the orbiter were able to analyze these plumes directly during the flybys. Titan and Enceladus could hardly seem more different, and yet they are linked by their origin in the Saturn system, by a magnetosphere that sweeps up mass and delivers energy, and by the possibility that one or both worlds harbor life. It is the goal of the NASA/ESA Titan Saturn System Mission (TSSM) to explore and investigate these exotic and inviting worlds, to understand their natures and assess the possibilities of habitability in this system so distant from our home world. Orbiting, landing, and ballooning at Titan represent a new and exciting approach to planetary exploration. The TSSM mission architecture inherently provides the optimal balance between science, risk, and cost using three guiding principles: Achieve science well beyond the high bar set by Cassini Huygens. The TSSM orbiter, lander, and balloon have been configured with instruments and operational concept that go well beyond Cassini-Huygens capabilities, thus ensuring dramatic remote observation and in situ science discoveries. Build upon successful design and operational experience and lessons learned. ESA has successful experience in designing and landing probes on Titan (Huygens), as does NASA in implementing an orbiter at Saturn (Cassini). Long life design rules and extensive operational experience in the Saturn system have been applied to form the TSSM concept. Lessons learned from Galileo, Cassini, New Horizons, and MRO have been applied to reduce risk and lower cost. Development by ESA of the montgolfiere combines prior experience with Earth and planetary balloon systems to enable innovative science and unprecedented mobility for surface exploration. Strong international partnership. TSSM represents a collaborative effort between NASA and ESA that is structured to provide the best possible mission at a reasonable cost to NASA and to ESA. This NASA-ESA partnership leverages resources to maximize science return, distribute risk, and ensure technical readiness.

  6. High-Tc/high-coupling relaxed PZT-based single crystal thin films

    NASA Astrophysics Data System (ADS)

    Wasa, K.; Matsushima, T.; Adachi, H.; Matsunaga, T.; Yanagitani, T.; Yamamoto, T.

    2015-03-01

    Pb(Zr,Ti)O3 (PZT)-based ferroelectric ceramics exhibit high piezoelectricity, however, their Curie temperature (Tc) values are not so high, i.e., Tc < 400 °C. PZT-based piezoelectric thin films with higher Tc would be beneficial for improved micro actuators, sensors, memories, and piezoelectric micro-electro mechanical systems. In-plane biaxial strained PZT thin films in a laminated composite structure are known to exhibit enhanced Tc; however, the thickness of PZT-based thin films is limited to below a critical thickness typically <50 nm. The Tc of relaxed PZT-based thin films with thicknesses greater than the critical thickness is the same as bulk Tc. However, a sort of relaxed PZT-based single-crystal thin films exhibit extraordinary high Tc, Tc = ˜600 °C. In addition, the films show extremely low dielectric constant, ?/?o ˜ 100 with high coupling factor, kt ˜ 0.7, and large remnant polarization, Pr ˜ 100 ?C/cm2. These exotic properties would result from the single-domain/single-crystal structure. The enhanced Tc is possibly caused by the highly stable interface between the PZT-based thin films and substrates. Their ferroelectric performances are beyond those of conventional PZT. The high-Tc/high-coupling performances are demonstrated, and the possible mechanisms of the high Tc behavior in relaxed PZT-based single-crystal thin films are discussed.

  7. 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.

  8. Photochemical aerosols in Titan's atmosphere

    Microsoft Academic Search

    M. Podolak; N. Noy; A. Bar-Nun

    1979-01-01

    The optical properties of polymers, produced photolytically from ethylene, which was detected in Titan's atmosphere and from acetylene or hydrogen cyanide which may be present there, were studied experimentally. It is shown that an aerosol consisting of polyethylene provides an excellent fit to the variation of Titan's albedo with wavelength, while polymers of acetylene or hydrogen cyanide do not. This

  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. Zirconate pyrochlores under high pressure

    SciTech Connect

    Xiao, Haiyan [Pacific Northwest National Laboratory (PNNL); Zhang, Fuxiang [University of Michigan; Gao, Fei [Pacific Northwest National Laboratory (PNNL); Ewing, Rodney C. [University of Michigan; Weber, William J [ORNL

    2010-01-01

    Ab initio total-energy calculations and x-ray diffraction measurements have been combined to study the phase stability of zirconate pyrochlores (A2Zr2O7; A=La, Nd and Sm) under pressures up to 50 GPa. Phase transformations to the defect-cotunnite structure are theoretically predicted at pressures of 22, 20 and 18 GPa, in excellent agreement with the experimentally determined values of 21, 22 and 18 GPa for La2Zr2O7, Nd2Zr2O7 and Sm2Zr2O7, respectively. Analysis of the elastic properties indicate that elastic anisotropy may be one of the driving forces for the pressure-induced cubic-to-noncubic phase transformation.

  11. Zirconate pyrochlores under high pressure

    SciTech Connect

    Xiao, Haiyan Y.; Zhang, F. X.; Gao, Fei; Lang, Maik; Ewing, Rodney C.; Weber, William J.

    2010-07-12

    Ab initio total-energy calculations and x-ray diffraction measurements have been combined to study the phase stability of zirconate pyrochlores (A2Zr2O7; A=La, Nd and Sm) under pressures up to 50 GPa. Phase transformations to the defect-cotunnite structure are theoretically predicted at pressures of 22, 20 and 18 GPa, in excellent agreement with the experimentally determined values of 21, 22 and 18 GPa for La2Zr2O7, Nd2Zr2O7 and Sm2Zr2O7, respectively. Analysis of the elastic properties indicates that elastic anisotropy may be one of the driving forces for the pressure-induced cubic-to-noncubic phase transformation.

  12. Refractory Materials of Zirconate. Part 2: Synthesis and some properties of strontium, zirconate, calcium zirconate and barium zirconate

    NASA Technical Reports Server (NTRS)

    Okubo, Tsutomo; Yonemochi, Osamu; Nakamura, Kazuo; Maeda, Minoru

    1988-01-01

    Chemical compounds SrZrO3, CaZrO3, and BaZrO3 were synthesized by solid reaction and arc fusion, and their properties examined. Results were as follows: (1) in the synthesis of CaZrO3 by solid reaction, ZrO2 solid solution with cubic form was produced, which then changed into CaZrO3; (2) the BaZrO3 was a cubic form and did not show any transformation, while SrZrO3 and CaZrO3 with an orthorhombic form transformed to a cubic form at high temperature; and (3) the solubility of BaZrO3 in acid and its vaporization rate at a high temperature were greater than those of zirconates.

  13. 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

  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. 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

  16. Titan Tusk Force Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Tusk Force Student Engagement Report FY 2012-2013 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, CSUF, Incorporated here at California State University, Fullerton. Program Overview Titan Tusk Force

  17. 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

  18. Shock Recrystallisation and Decomposition of Zircon

    NASA Astrophysics Data System (ADS)

    Timms, N. E.; Erickson, T. E.; Schmieder, M.; Tohver, E.

    2014-09-01

    In this study, we present the first electron backscatter diffraction (EBSD) characterization of granular and decomposed zircon in order to investigate the mechanism(s) by which these microstructures are produced.

  19. Multiple origins of zircons in jadeitite

    Microsoft Academic Search

    Bin Fu; John W. Valley; Noriko T. Kita; Michael J. Spicuzza; Chad Paton; Tatsuki Tsujimori; Michael Bröcker; George E. Harlow

    2010-01-01

    Jadeitites form from hydrothermal fluids during high pressure metamorphism in subduction environments; however, the origin\\u000a of zircons in jadeitite is uncertain. We report ion microprobe analyses of ?18O and Ti in zircons, and bulk ?18O data for the jadeitite whole-rock from four terranes: Osayama serpentinite mélange, Japan; Syros mélange, Greece; the Motagua\\u000a Fault zone, Guatemala; and the Franciscan Complex, California.

  20. Metamictization of zircon: Raman spectroscopic study

    NASA Astrophysics Data System (ADS)

    Zhang, Ming; Salje, Ekhard K. H.; Farnan, Ian; Graeme-Barber, Ann; Daniel, Philippe; Ewing, Rodney C.; Clark, Andrew M.; Leroux, Hugues

    2000-02-01

    Raman spectroscopy of radiation-damaged natural zircon samples shows increased line broadening and shifts of phonon frequencies with increasing radiation dose. Stretching and bending frequencies of SiO4 tetrahedra soften dramatically with increasing radiation damage. The frequency shifts can be used to determine the degree of radiation damage. Broad spectral bands related to Si-O stretching vibrations between 900 and 1000 cm-1 were observed in metamict/amorphous zircon. The radiation-dose-independent spectral profiles and the coexistence of this broad background and relative sharp Raman modes in partially damaged samples indicate that these bands are correlated with amorphous domains in zircon. The spectral profiles of metamict zircon suggest that in comparison with silica, the SiO4 tetrahedra are less polymerized in metamict zircon. This study also shows that ZrO2 and SiO2 are not the principal products of metamictization in zircon. No indication of bulk chemical unmixing of zircon into ZrO2 and SiO2 was found in 26 samples with a large variation of radiation damage (maximum dose: 23.5 × 1018 icons/Journals/Common/alpha" ALT="alpha" ALIGN="TOP"/> -events g-1 ). Only one sample showed clearly, in all measured sample areas, extra sharp lines at 146, 260, 312, 460 and 642 cm-1 characteristic of tetragonal ZrO2 . The geological (and possibly artificial heating) history of this sample is not known. It is concluded that radiation damage without subsequent high temperature annealing does not cause unmixing of zircon into constituent oxides.

  1. 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- tive amounts of Ba and Sr. TC for pure barium t

  2. 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.

  3. Zinc titanate sorbents

    DOEpatents

    Gupta, Raghubir P. (Durham, NC); Gangwal, Santosh K. (Durham, NC); Jain, Suresh C. (Germantown, MD)

    1998-01-01

    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.degree. C. to about 950.degree. 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 .mu., and about 1 part titanium dioxide having a median particle size of less than about 1 .mu.. 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.

  4. Titan impacts and escape

    NASA Astrophysics Data System (ADS)

    Korycansky, D. G.; Zahnle, Kevin J.

    2011-01-01

    We report on hydrodynamic calculations of impacts of large (multi-kilometer) objects on Saturn's moon Titan. We assess escape from Titan, and evaluate the hypothesis that escaping ejecta blackened the leading hemisphere of Iapetus and peppered the surface of Hyperion. We carried out two- and three-dimensional simulations of impactors ranging in size from 4 to 100 km diameter, impact velocities between 7 and 15 km s -1, and impact angles from 0° to 75° from the vertical. We used the ZEUSMP2 hydrocode for the calculations. Simulations were made using three different geometries: three-dimensional Cartesian, two-dimensional axisymmetric spherical polar, and two-dimensional plane polar. Three-dimensional Cartesian geometry calculations were carried out over a limited domain (e.g. 240 km on a side for an impactor of size di = 10 km), and the results compared to ones with the same parameters done by Artemieva and Lunine (2005); in general the comparison was good. Being computationally less demanding, two-dimensional calculations were possible for much larger domains, covering global regions of the satellite (from 800 km below Titan's surface to the exobase altitude 1700 km above the surface). Axisymmetric spherical polar calculations were carried out for vertical impacts. Two-dimensional plane-polar geometry calculations were made for both vertical and oblique impacts. In general, calculations among all three geometries gave consistent results. Our basic result is that the amount of escaping material is less than or approximately equal to the impactor mass even for the most favorable cases. Amounts of escaping material scaled most strongly as a function of velocity, with high-velocity impacts generating the largest amount, as expected. Dependence of the relative amount of escaping mass fesc = mesc/ Mi on impactor diameter di was weak. Oblique impacts (impact angle ?i > 45°) were more effective than vertical or near-vertical impacts; ratios of mesc/ Mi ˜ 1-2 were found in the simulations.

  5. Titan Airship Surveyor

    NASA Technical Reports Server (NTRS)

    Kerzhanovich, V.; Yavrouian, A.; Cutts, J.; Colozza, A.; Fairbrother, D.

    2001-01-01

    Saturn's moon Titan is considered to be one of the prime candidates for studying prebiotic materials - the substances that precede the formation of life but have disappeared from the Earth as a result of the evolution of life. A unique combination of a dense, predominantly nitrogen, atmosphere (more than four times that of the Earth), low gravity (six times less than on the Earth) and small temperature variations makes Titan the almost ideal planet for studies with lighter-than-air aerial platforms (aerobots). Moreover, since methane clouds and photochemical haze obscure the surface, low-altitude aerial platforms are the only practical means that can provide global mapping of the Titan surface at visible and infrared wavelengths. One major challenge in Titan exploration is the extremely cold atmosphere (approx. 90 K). However, current material technology the capability to operate aerobots at these very low temperatures. A second challenge is the remoteness from the Sun (10 AU) that makes the nuclear (radioisotopic) energy the only practical source of power. A third challenge is remoteness from the Earth (approx. 10 AU, two-way light-time approx. 160 min) which imposes restrictions on data rates and makes impractical any meaningful real-time control. A small-size airship (approx. 25 cu m) can carry a payload approximately 100 kg. A Stirling engine coupled to a radioisotope heat source would be the prime choice for producing both mechanical and electrical power for sensing, control, and communications. The cold atmospheric temperature makes Stirling machines especially effective. With the radioisotope power source the airship may fly with speed approximately 5 m/s for a year or more providing an excellent platform for in situ atmosphere measurements and a high-resolution remote sensing with unlimited access on a global scale. In a station-keeping mode the airship can be used for in situ studies on the surface by winching down an instrument package. Floating above the surface allows relatively simple means for flight control. Mission requirements and possible methods of navigation, control, data acquisition, and communications are discussed. The presentation describes also the state-of-the art and current progress in aerial deployed aerobots.

  6. Touchdown on Titan

    NASA Technical Reports Server (NTRS)

    Morring, Frank, Jr.

    2004-01-01

    Europe's Huygens probe is on target for a Dec. 25 separation from the Cassini Saturn orbiter that has carried it like a baby for more than seven years. The probe will spend three weeks coasting to a plunge into Titan's thick atmosphere on the morning of Jan. 14. If all goes as planned, the 349-kg. Huygens will spend more than 2 hr. descending by parachute to the mysterious surface of the planet-sized moon, and hopefully devote yet more time to broadcasting data after it lands. Before the day is over, Huygens is programmed to beam about 30 megabytes of data - including some 1,100 images-back to Earth through Cassini, a trip that will take some 75 min. to complete over the 1- billion-km. distance that separates the two planets. Within that data should be answers to questions that date back to 1655, when Dutch astronomer Christiaan Huygens found the moon with a homemade telescope and named it for the family of giants the ancient Greeks believed once ruled the earth. In the Solar System, there is no other world like Titan, with a nitrogen and methane atmospheric and a cold, hidden surface darker than Earth under the full Moon.

  7. Monosodium Titanate Sludge Filtration

    SciTech Connect

    Dworjanyn, L.O.

    2000-11-07

    Good filterability of tetraphenylborate (TPB) slurry is attributed to the hydrophobic nature of crystalline organic TPB that forms a firm but porous filter cake, allowing salt solution to pass through without unduly compressing the cake. Addition of inorganic sludge or monosodium titanate (MST) has an adverse effect on filtration, but the overall filtration rate with TPB is satisfactory. Poor cross-flow filtration performance for the Salt Disposition Alternatives requiring MST filtration is attributed primarily to the difficulty in filtering the residual inorganic sludge rich in iron and aluminum precipitates. Ferric hydrolysis products and colloids form a bulky and sticky filter cake significantly reducing filtration rate. Similarly poor filtration rates were observed in the BNFL ferric/ferrous precipitation process, necessitating a change to permanganate precipitation. This report, based on a few sludge settling observations, does not resolve the MST/Sludge filterability issue. However, it does identify the need for a change in emphasis from cross-flow optimization to understanding and controlling the chemistry and physics of alkaline inorganic particle suspensions and filterability. Promising potential exists to identify or develop surfactants or flocculants to enhance filterability of SRS sludge and monosodium titanate. Additional work is needed to provide a basic understanding of the nature of caustic sludge filter cake formation.

  8. Processing Effects for Integrated PZT: Residual Stress, Thickness, and Dielectric Properties

    E-print Network

    Sottos, Nancy R.

    reflectance to determine wafer curvature, derived biaxial tensile stress values of 150 and 180 MPa for PZT of biaxial tensile stress may be present in PZT films deposited onto Pt/Ti/SiO2//Si substrates of film processing. Residual stress was measured by a wafer curvature method. A series-capacitor model

  9. SHM FOR RC STRUCTURE USING PZT REBAR ACTIVE SENSING SYSTEM NUMERICAL STUDY

    E-print Network

    Boyer, Edmond

    , Juan Yi1 1 Department of Civil Engineering, School of Naval Architecture, Ocean, and Civil Engineering The guided stress wave method uses time of arrival and amplitude change of signals to detect defects Beam PVC pipe as debond 2x4 ¼" disk PZT ­ 16" apart a) Layout of the PZT rebar concrete beam b) Test

  10. Local Structure of PZT Valentine R. Cooper, Ilya Grinberg, Nathan R. Martin

    E-print Network

    Rappe, Andrew M.

    lattice that gives PZT its interesting properties. CP626, Fundamental Physics of Ferroelectrics 2002Local Structure of PZT Valentine R. Cooper, Ilya Grinberg, Nathan R. Martin and Andrew M. Rappe in the magnitude and direction of the B-cation distortions within their oxygen octahedra. There is also disorder

  11. Titan Recreation-Open Recreation Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Recreation-Open Recreation Student Engagement Report FY 2011-2012 Purpose Statement Titan and overall wellness. Titan Recreation also provides opportunities for cooperative and competitive play, team building and interpersonal skills. Leadership and participation opportunities within Titan

  12. Titan Recreation-Intramural Sports Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Recreation-Intramural Sports Student Engagement Report FY 2010-2011 Purpose Statement Titan and overall wellness. Titan Recreation also provides opportunities for cooperative and competitive play, team building and interpersonal skills. Leadership and participation opportunities within Titan

  13. Titan Recreation-Intramural Sports Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Recreation-Intramural Sports Student Engagement Report FY 2012-2013 Purpose Statement Titan fitness and overall wellness. Titan Recreation also provides opportunities for cooperative and competitive within Titan Recreation are designed to enhance social, psychological and physiological development

  14. Titan Recreation-Open Recreation Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Recreation-Open Recreation Student Engagement Report FY 2010-2011 Purpose Statement Titan and overall wellness. Titan Recreation also provides opportunities for cooperative and competitive play, team building and interpersonal skills. Leadership and participation opportunities within Titan

  15. Titan Recreation-Intramural Sports Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Recreation-Intramural Sports Student Engagement Report FY 2011-2012 Purpose Statement Titan fitness and overall wellness. Titan Recreation also provides opportunities for cooperative and competitive within Titan Recreation are designed to enhance social, psychological and physiological development

  16. Titan Recreation-Open Recreation Student Engagement Report

    E-print Network

    de Lijser, Peter

    Titan Recreation-Open Recreation Student Engagement Report FY 2012-2013 Purpose Statement Titan and overall wellness. Titan Recreation also provides opportunities for cooperative and competitive play, team building and interpersonal skills. Leadership and participation opportunities within Titan

  17. A new device with PZT ultrasonic transducers in MEMS technology

    NASA Astrophysics Data System (ADS)

    Hirsch, Soeren; Doerner, Steffen; Schimpf, Stefan; Lucklum, Ralf; Hauptmann, Peter; Schmidt, Bertram

    2006-04-01

    Thick-film piezoelectric transducers have been produced and tested for implementation into a MEMS ultrasonic sensor array. The arrays are intended to be used for beam forming in sensing applications for fluidics in channels at millimeter or micrometer scale (e.g. flow rate measurement, detection of beads, bubbles). Stripe and matrix aligned elements have been fabricated for one-dimensional and two-dimensional beam steering, respectively. In this contribution we further concentrate on an improved Q-factor and PZT layer homogeneity as a major requirement for the transducer elements.

  18. Elevation distribution of Titan’s craters suggests extensive wetlands

    NASA Astrophysics Data System (ADS)

    Neish, Catherine; Lorenz, R.

    2013-10-01

    Using a new global topographic map of Titan, we find that craters on Titan preferentially lie at higher than average elevations. We explore several explanations for this observed behavior, and judge the most reasonable explanation to be the presence of widespread wetlands of liquid hydrocarbons at low elevations over much of geologic time. Impacts into a shallow marine environment or a saturated layer of sediments more than several hundred meters thick would produce crater morphologies similar to terrestrial submarine impacts. These are known to lack significant topographic expression, and would thus be difficult to observe with the Cassini spacecraft. Since Titan’s near-surface methane inventory likely fluctuated over geologic time, with episodic delivery and continuous depletion, a few craters at low elevations can nonetheless be expected.

  19. Numerical analysis and control for cantilever flexible beams using PZT patches

    NASA Astrophysics Data System (ADS)

    Yan, Shi; Zhang, Hao

    2008-03-01

    This paper presents a numerical study on a vibration control of a cantilever flexible beam using PZT patches. The PZT patches used as both actuators and sensors were adopted in the forms of surface-bond devices on the flexible aluminum beam to control actively the vibration responses. The beam was actuated electrically by the PZT actuator to generate the vibration and the feedback signals were collected by the PZT sensors during the numerical analysis and experimental validation. A finite element method (FEM) in which the materials of the beam and PZTs were coupled was used numerically to analyze the vibration and structural control. A compare study between the numerical simulation and experiment results was finished. The results of the FEM simulation showed that it was effective to use PZT patches to control the responses of flexible structure and the proposed numerical method was also successful in analyzing the vibration responses of the coupled material structures.

  20. Effect of substrate bending on the piezoelectric measurement of PZT thin film

    NASA Astrophysics Data System (ADS)

    Xu, Xiaohui; Tang, Jianhong; He, Liangna

    2009-05-01

    Bonding conditions between PZT thin film and sample holder greatly affect the strain measurement of the PZT sample. The influence of various bonding conditions on the measured displacement were analyzed using finite element analysis (FEA). One-end fixed sample induces the maximum bending displacement. Experiments were performed on sol-gel derived PZT thin film. The voltage-displacement curve and "butterfly" loop were measured using laser Doppler method with phase detection. Experimental results agreed well with the simulated ones. The measured frequency dependence of piezoelectric response of PZT thin film indicated that, if the operating frequency was lower than 2 kHz, good bonding effect could be obtained when the entire back surface of the sample was glued to a rigid supporter using epoxy resin. A simple bonding model which considered the adhesives as a spring was used to estimate the frequency response of PZT thin film sample.

  1. Does ice float in Titan’s lakes and seas?

    NASA Astrophysics Data System (ADS)

    Hofgartner, Jason D.; Lunine, Jonathan I.

    2013-03-01

    We model Titan’s lakes and seas as methane-ethane-nitrogen systems and model the buoyancy of solids in these systems assuming thermodynamic equilibrium. We find that ice will float in methane-rich lakes for all temperatures below the freezing point of pure methane and that ice will also float in ethane-rich seas provided the ice has an air porosity of greater than 5% by volume.

  2. Geochemical signatures and magmatic stability of terrestrial impact produced zircon

    NASA Astrophysics Data System (ADS)

    Wielicki, Matthew M.; Harrison, T. Mark; Schmitt, Axel K.

    2012-03-01

    Understanding the role of impacts on early Earth has major implications to near surface conditions, but the apparent lack of preserved terrestrial craters > 2 Ga does not allow a direct sampling of such events. Ion microprobe U-Pb ages, REE abundances and Ti-in-zircon thermometry for impact produced zircon are reported here. These results from terrestrial impactites, ranging in age from ~ 35 Ma to ~ 2 Ga, are compared with the detrital Hadean zircon population from Western Australia. Such comparisons may provide the only terrestrial constraints on the role of impacts during the Hadean and early Archean, a time predicted to have a high bolide flux. Ti-in-zircon thermometry indicates an average of 773 °C for impact-produced zircon, ~ 100 °C higher than the average for Hadean zircon crystals. The agreement between whole-rock based zircon saturation temperatures for impactites and Ti-in-zircon thermometry (at aTiO2 = 1) implies that Ti-in-zircon thermometry record actual crystallization temperatures for impact melts. Zircon saturation modeling of Archean crustal rock compositions undergoing thermal excursions associated with the Late Heavy Bombardment predicts equally high zircon crystallization temperatures. The lack of such thermal signatures in the Hadean zircon record implies that impacts were not a dominant mechanism of producing the preserved Hadean detrital zircon record.

  3. Titan's greenhouse and antigreenhouse effects

    NASA Technical Reports Server (NTRS)

    Mckay, Christopher P.; Pollack, James B.; Courtin, Regis

    1992-01-01

    Thermal mechanisms active in Titan's atmosphere are discussed in a brief review of data obtained during the Voyager I flyby in 1980. Particular attention is given to the greenhouse effect (GHE) produced by atmospheric H2, N2, and CH4; this GHE is stronger than that on earth, with CH4 and H2 playing roles similar to those of H2O and CO2 on earth. Also active on Titan is an antigreenhouse effect, in which dark-brown and orange organic aerosols block incoming solar light while allowing IR radiation from the Titan surface to escape. The combination of GHE and anti-GHE leads to a surface temperature about 12 C higher than it would be if Titan had no atmosphere.

  4. Seasonal Changes in Titan's Meteorology

    NASA Technical Reports Server (NTRS)

    Turtle, E. P.; DelGenio, A. D.; Barbara, J. M.; Perry, J. E.; Schaller, E. L.; McEwen, A. S.; West, R. A.; Ray, T. L.

    2011-01-01

    The Cassini Imaging Science Subsystem has observed Titan for 1/4 Titan year, and we report here the first evidence of seasonal shifts in preferred locations of tropospheric methane clouds. South \\polar convective cloud activity, common in late southern summer, has become rare. North \\polar and northern mid \\latitude clouds appeared during the approach to the northern spring equinox in August 2009. Recent observations have shown extensive cloud systems at low latitudes. In contrast, southern mid \\latitude and subtropical clouds have appeared sporadically throughout the mission, exhibiting little seasonality to date. These differences in behavior suggest that Titan s clouds, and thus its general circulation, are influenced by both the rapid temperature response of a low \\thermal \\inertia surface and the much longer radiative timescale of Titan s cold thick troposphere. North \\polar clouds are often seen near lakes and seas, suggesting that local increases in methane concentration and/or lifting generated by surface roughness gradients may promote cloud formation. Citation

  5. The TITAN reversed-field-pinch fusion reactor study

    SciTech Connect

    Not Available

    1990-01-01

    This report discusses research on the titan-1 fusion power core. The major topics covered are: titan-1 fusion-power-core engineering; titan-1 divertor engineering; titan-1 tritium systems; titan-1 safety design and radioactive-waste disposal; and titan-1 maintenance procedures.

  6. NOVA Online: Titanic's Lost Sister

    NSDL National Science Digital Library

    Companion site to an original broadcast on January 28, 1997. When Titanic sank, construction on her sister ship, Britannic, was interrupted so she could be overhauled with new regulations. Britannic sank in 1916 in less than an hour. Includes interview with Robert Ballard, who found the sunken Titanic, an interactive search, and salvage activity. Others resources available: written transcript, teacher's guide, students activities, and links to additional resources.

  7. Seasonal changes in Titan's meteorology

    Microsoft Academic Search

    E. P. Turtle; A. D. Del Genio; J. M. Barbara; J. E. Perry; E. L. Schaller; A. S. McEwen; R. A. West; T. L. Ray

    2011-01-01

    The Cassini Imaging Science Subsystem has observed Titan for ?1\\/4 Titan year, and we report here the first evidence of seasonal shifts in preferred locations of tropospheric methane clouds. South-polar convective cloud activity, common in late southern summer, has become rare. North-polar and northern mid-latitude clouds appeared during the approach to the northern spring equinox in August 2009. Recent observations

  8. Seasonal changes in Titan's meteorology

    Microsoft Academic Search

    E. P. Turtle; A. D. Del Genio; J. M. Barbara; J. E. Perry; E. L. Schaller; A. S. McEwen; R. A. West; T. L. Ray

    2011-01-01

    The Cassini Imaging Science Subsystem has observed Titan for ˜1\\/4 Titan year, and we report here the first evidence of seasonal shifts in preferred locations of tropospheric methane clouds. South-polar convective cloud activity, common in late southern summer, has become rare. North-polar and northern mid-latitude clouds appeared during the approach to the northern spring equinox in August 2009. Recent observations

  9. Impact origin of Titan's atmosphere

    NASA Technical Reports Server (NTRS)

    Zahnle, Kevin; Dones, L.

    1992-01-01

    The reason why Titan has a thick atmosphere while its Jovian clones Ganymede and Callisto have nothing is addressed. It is argued that this contrast is a predictable consequence of impact erosion, i.e., the escape of atmospheric gases as a consequence of hypervelocity impact, the average impact velocity of stray bodies on Titan being lower than on Ganymede and Callisto. A model to examine this hypothesis is presented.

  10. Piezoelectric micromachined ultrasonic transducers based on PZT thin films.

    PubMed

    Muralt, Paul; Ledermann, Nicolas; Baborowski, Jacek; Barzegar, Abdolghaffar; Gentil, Sandrine; Belgacem, Brahim; Petitgrand, Sylvain; Bosseboeuf, Alain; Setter, Nava

    2005-12-01

    This paper describes fabrication and characterization results of piezoelectric micromachined ultrasonic transducers (pMUTs) based on 2-microm-thick Pb(Zr0.53Ti0.47O3) (PZT) thin films. The applied structures are circular plates held at four bridges, thus partially unclamped. A simple analytical model for the fully clamped structure is used as a reference to optimize design parameters such as thickness relations and electrodes, and to provide approximate predictions for coupling coefficients related to previously determined thin film properties. The best coupling coefficient was achieved with a 270-microm plate and amounted to kappa2 = 5.3%. This value compares well with the calculated value based on measured small signal dielectric (epsilon = 1050) and piezoelectric (e3l,f = 15 Cm(-2)) properties of the PZT thin film at 100 kV/cm dc bias. The resonances show relatively large Q-factors, which can be partially explained by the small diameters as compared to the sound wavelength in air and in the test liquid (Fluorinert 77). A transmit-receive experiment with two quasi-identical pMUTs was performed showing significant signal transmission up to a distance of 20 cm in air and 2 cm in the test liquid. PMID:16463493

  11. Crack detection of railway turnouts using PZT sensors (presentation video)

    NASA Astrophysics Data System (ADS)

    Ni, Yiqing; Li, Z. G.; Wu, F.

    2014-05-01

    Railway turnouts (railroad switches) are the weakest components of a rail track system. Cracks may occur in the railway turnouts due to cyclic loadings and impact loadings imposed by passing trains. It is of great significance to continuously monitor the health condition of the railway turnouts and promptly detect crack once it initiates. It is well-known that acoustic emission (AE) signals are generated when a crack initiates and propagates. Detecting the high-frequency AE signals by piezoelectric sensors can help identify the crack and its location. This paper reports the design and implementation of a PZT-based system for crack monitoring of railway turnouts. This online monitoring system is activated for signal collection by a trigger system when a train is arriving to pass through the instrumented railway turnout. It mainly detects the AE signals generated when a crack initiates during the train passage or when the initiated crack expands during the passage of a heavy haul wagon. This system has been installed on a railroad line for over one year and has successfully detected the damage occurring at a railroad switch during its service period. This paper also briefs a guided-wave-based system for monitoring of micro-cracks in rail tracks by integrating FBG and PZT sensors.

  12. Poling process optimization of piezo nano composite PZT/polimer

    NASA Astrophysics Data System (ADS)

    Ridlo, M. Rosyid; Lestari, Titik; Mardiyanto, Oemry, Achiar

    2013-09-01

    The objective of poling process is to make the electric dipole directions to be parallel in the inside perovskite crystal of piezo materials. In simply way, poling was carried out by giving the two sides of a piezo material by highly electrical potential. More parallel of electrical dipoles, it is more strength the piezo characteristics. The optimization involved control of temperature, time depth and the electrical voltage. The samples was prepared by solgel method with precursor tetrabutyl titanat Ti(OC4H9)4, zirconium nitrat Zr(NO3)4?5H2O, Pb(CH3COO)2?3H2O and solution ethylene glycol. Molar ratio Pb:Zr:Ti = 1,1:0,52:0,48 with concidering lossed Pb. Result of solgel process is nano powder PZT. The formed nano powder PZT was then mixed with polimer PVDF and pressed 10 MPa at 150 °C with the size 15 mm in diameter. After poling, piezoelectric constant d33 was measured. The highest d33 = 45 pC/N was found at poling parameters V = 5 kV/ mm, T = 120 °C dan time depth = 1 hours.

  13. Life on Titan

    NASA Astrophysics Data System (ADS)

    Potashko, Oleksandr

    Volcanoes engender life on heavenly bodies; they are pacemakers of life. All planets during their period of formation pass through volcanism hence - all planets and their satellites pass through the life. Tracks of life If we want to find tracks of life - most promising places are places with volcanic activity, current or past. In the case of just-in-time volcanic activity we have 100% probability to find a life. Therefore the most perspective “search for life” are Enceladus, Io and comets, further would be Venus, Jupiter’s satellites, Saturn’s satellites and first of all - Titan. Titan has atmosphere. It might be result of high volcanic activity - from one side, from other side atmosphere is a necessary condition development life from procaryota to eucaryota. Existence of a planet means that all its elements after hydrogen formed just there inside a planet. The forming of the elements leads to the formation of mineral and organic substances and further to the organic life. Development of the life depends upon many factors, e.g. the distance from star/s. The intensity of the processes of the element formation is inversely to the distance from the star. Therefore we may suppose that the intensity of the life in Mercury was very high. Hence we may detect tracks of life in Mercury, particularly near volcanoes. The distance from the star is only one parameter and now Titan looks very active - mainly due to interior reason. Its atmosphere compounds are analogous to comet tail compounds. Their collation may lead to interesting result as progress occurs at one of them. Volcanic activity is as a source of life origin as well a reason for a death of life. It depends upon the thickness of planet crust. In the case of small thickness of a crust the probability is high that volcanoes may destroy a life on a planet - like Noachian deluge. Destroying of the life under volcano influences doesn’t lead to full dead. As result we would have periodic Noachian deluge or nuclear winter. These events are known as extinctions or ice ages. The crust of a planet of the Earth group is formed at the outer edge of the body. The planets after asteroid belt like Jupiter or Saturn probably form their “crusts” in the centre of the body. Due to we may see internal kitchen of element forming in detail. This processes lead to the organic life, which we may detect at the atmospheres of Jupiter, Saturn, Neptune, and Pluto. But their satellites look like earth planet group - with outer crust. Huygens considered that God's wisdom and providence is clearest in the creation of life, and Earth holds no privileged position in the heavens that life must be universal. “Huygens” helps find life on Titan

  14. Titan's South Polar Cloud

    NASA Astrophysics Data System (ADS)

    Toledo, D.; Rannou, P.; West, R. A.; Lavvas, P.; Del Genio, A. D.; Barbara, J. M.; Roy, M.; Turtle, E. P.

    2014-04-01

    Cassini/ISS cameras detected a newly formed large cloud in the south polar region of Titan on 2012-178 (June 27). Images of this cloud in the continuum filters at 889 nm (MT3) and 935 nm (CB3) clearly reveal different characteristics relative to the'detached haze' layer that extends over all south latitudes. Figure 1 shows I/F at 889 nm, where the cloud patch is observed beyond the latitude -77º and with values of the SZA higher than 90º. In this work, we analyze different MT3/CB3 images taken by ISS cameras, in order to characterize the optical properties of this cloud as well as its altitude. We first analyze images in the MT3 filter at different angles of observation in order to have some constraints on the altitude of the cloud, and subsequently the cloud optical properties are estimated by using radiative transfer simulations.

  15. Chemistry in Titan

    NASA Astrophysics Data System (ADS)

    Plessis, S.; Carrasco, N.; Pernot, P.

    2009-04-01

    Modelling the chemical composition of Titan's ionosphere is a very challenging issue. Latest works perform either inversion of CASSINI's INMS mass spectra (neutral[1] or ion[2]), or design coupled ion-neutral chemistry models[3]. Coupling ionic and neutral chemistry has been reported to be an essential feature of accurate modelling[3]. Electron Dissociative Recombination (EDR), where free electrons recombine with positive ions to produce neutral species, is a key component of ion-neutral coupling. There is a major difficulty in EDR modelling: for heavy ions, the distribution of neutral products is incompletely characterized by experiments. For instance, for some hydrocarbon ions only the carbon repartition is measured, leaving the hydrogen repartition and thus the exact neutral species identity unknown[4]. This precludes reliable deterministic modelling of this process and of ion-neutral coupling. We propose a novel stochastic description of the EDR chemical reactions which enables efficient representation and simulation of the partial experimental knowledge. The description of products distribution in multi-pathways reactions is based on branching ratios, which should sum to unity. The keystone of our approach is the design of a probability density function accounting for all available informations and physical constrains. This is done by Dirichlet modelling which enables one to sample random variables whose sum is constant[5]. The specifics of EDR partial uncertainty call for a hierarchiral Dirichlet representation, which generalizes our previous work[5]. We present results on the importance of ion-neutral coupling based on our stochastic model. C repartition H repartition (measured) (unknown ) â?? C4H2 + 3H2 + H .. -â?? C4 . â?? C4H2 + 7H â?? C3H8. + CH C4H+9 + e- -â?? C3 + C .. â?? C3H3 + CH2 + 2H2 â?? C2H6 + C2H2 + H .. -â?? C2 + C2 . â?? 2C2H2 + 2H2 + H (1) References [1] J. Cui, R.V. Yelle, V. Vuitton, J.H. Waite Jr., W.T. Kasprzak, D.A. Gell, H.B. Niemann, I.C.F. Müller-Wodarg, N. Borggren, G.G. Fletcher, E.L. Patrick, E. Raaen, and B.A. Magee. Analysis of Titan's neutral upper atmosphere from Cassini ion neutral mass spectrometer measurements. Icarus, In Press, Accepted Manuscript:-, 2008. [2] V. Vuitton, R. V. Yelle, and M.J. McEwan. Ion chemistry and N-containing molecules in Titan's upper atmosphere. Icarus, 191:722-742, 2007. [3] V. De La Haye, J.H. Waite Jr., T.E. Cravens, I.P. Robertson, and S. Lebonnois. Coupled ion and neutral rotating model of Titan's upper atmosphere. Icarus, 197(1):110 - 136, 2008. [4] J. B. A. Mitchell, C. Rebrion-Rowe, J. L. Le Garrec, G. Angelova, H. Bluhme, K. Seiersen, and L. H. Andersen. Branching ratios for the dissociative recombination of hydrocarbon ions. I: The cases of C4H9+ and C4H5+. International Journal of Mass Spectrometry, 227(2):273-279, June 2003. [5] N. Carrasco and P. Pernot. Modeling of branching ratio uncertainty in chemical networks by Dirichlet distributions. Journal of Physical Chemistry A, 11(18):3507-3512, 2007.

  16. Simulations of Titan's paleoclimate

    NASA Astrophysics Data System (ADS)

    Lora, Juan M.; Lunine, Jonathan I.; Russell, Joellen L.; Hayes, Alexander G.

    2014-11-01

    We investigate the effects of varying Saturn's orbit on the atmospheric circulation and surface methane distribution of Titan. Using a new general circulation model of Titan's atmosphere, we simulate its climate under four characteristic configurations of orbital parameters that correspond to snapshots over the past 42 kyr, capturing the amplitude range of long-period cyclic variations in eccentricity and longitude of perihelion. The model, which covers pressures from the surface to 0.5 mbar, reproduces the present-day temperature profile and tropospheric superrotation. In all four simulations, the atmosphere efficiently transports methane poleward, drying out the low- and mid-latitudes, indicating that these regions have been desert-like for at least tens of thousands of years. Though circulation patterns are not significantly different, the amount of surface methane that builds up over either pole strongly depends on the insolation distribution; in the present-day, methane builds up preferentially in the north, in agreement with observations, where summer is milder but longer. The same is true, to a lesser extent, for the configuration 14 kyr ago, while the south pole gains more methane in the case for 28 kyr ago, and the system is almost symmetric 42 kyr ago. This confirms the hypothesis that orbital forcing influences the distribution of surface liquids, and that the current observed asymmetry could have been partially or fully reversed in the past. The evolution of the orbital forcing implies that the surface reservoir is transported on timescales of ?30 kyr, in which case the asymmetry reverses with a period of ?125 kyr. Otherwise, the orbital forcing does not produce a net asymmetry over longer timescales, and is not a likely mechanism for generating the observed dichotomy.

  17. Synthesis and piezoresponse of highly ordered Pb(Zr0.53Ti0.47)O3 nanowire arrays

    NASA Astrophysics Data System (ADS)

    Zhang, X. Y.; Zhao, X.; Lai, C. W.; Wang, J.; Tang, X. G.; Dai, J. Y.

    2004-11-01

    We report the synthesis and characterization of ferroelectric lead zirconate titanate Pb(Zr0.53Ti0.47)O3 (PZT) nanowires. The PZT nanowires, with diameters of about 45nm and lengths of about 6?m, were fabricated by means of a sol-gel method utilizing nanochannel alumina templates. After postannealing at 700°C, the PZT nanowires exhibit a polycrystalline microstructure, and x-ray diffraction and transmission electron microscopy study revealed their perovskite crystal structure. The piezoelectric characteristics of individual PZT nanowires were demonstrated by piezoresponse force microscopy.

  18. TITAN Overview 1 TITAN: A NextGeneration Infrastructure for Integrating

    E-print Network

    California at Berkeley, University of

    TITAN Overview 1 TITAN: A Next­Generation Infrastructure for Integrating Computing and communication infrastructure a new type of computing system, called Titan. This computing system comprises be examined on­line at URL http://www.cs/projects/titan/index.html In this report we outline the progress

  19. Nondetection of Titan lightning radio emissions with Cassini/RPWS after 35 close Titan flybys

    E-print Network

    Gurnett, Donald A.

    Nondetection of Titan lightning radio emissions with Cassini/RPWS after 35 close Titan flybys G on the nondetection of radio emissions associated with possible lightning flashes in Titan's atmosphere by the Cassini/RPWS (Radio and Plasma Wave Science) instrument. A valid proof for Titan lightning would be the detection

  20. Fission track dating of kimberlitic zircons

    USGS Publications Warehouse

    Haggerty, S.E.; Raber, E.; Naeser, C.W.

    1983-01-01

    The only reliable method for dating kimberlites at present is the lengthy and specialized hydrothermal procedure that extracts 206Pb and 238U from low-uranium zircons. This paper describes a second successful method by fission track dating of large single-crystal zircons, 1.0-1.5 cm in dimension. The use of large crystals overcomes the limitations imposed in conventional fission track analysis which utilizes crushed fragments. Low track densities, optical track dispersion, and the random orientation of polished surfaces in the etch and irradiation cycle are effectively overcome. Fission track ages of zircons from five African kimberlites are reported, from the Kimberley Pool (90.3 ?? 6.5 m.y.), Orapa (87.4 ?? 5.7 and 92.4 ?? 6.1 m.y.), Nzega (51.1 ?? 3.8 m.y.), Koffiefontein (90.0 ?? 8.2 m.y.), and Val do Queve (133.4 ?? 11.5 m.y.). In addition we report the first radiometric ages (707.9 ?? 59.6 and 705.5 ?? 61.0 m.y.) of crustal zircons from kimberlites in northwest Liberia. The fission track ages agree well with earlier age estimates. Most of the zircons examined in this study are zoned with respect to uranium but linear correlations are established (by regression analysis) between zones of variable uranium content, and within zones of constant uranium content (by analysis of variance). Concordance between the fission track method and the U/Pb technique is established and we concluded that track fading from thermal annealing has not taken place. Kimberlitic zircons dated in this study, therefore, record the time of eruption. ?? 1983.

  1. Effects of Mn doping on the ferroelectric properties of PZT thin films

    NASA Astrophysics Data System (ADS)

    Zhang, Qi

    2004-01-01

    The effects of Mn doping on the ferroelectric properties of Pb(Zr0.3Ti0.7)O3 (PZT) thin films on Pt/Ti/SiO2/Si substrates have been investigated. The composition of the PZT and Mn doping level are Pb(Zr0.3Ti0.7)1-xMnxO3 (x = 0,0.2,0.5,1,2,4 mol%). The PZT thin films doped with a small amount of Mn2+ (x les 1) showed almost no hysteretic fatigue up to 1010 switching bipolar pulse cycles, coupled with excellent retention properties. However, excessive additions of manganese made the fatigue behaviour worse. We propose that the addition of small amounts of Mn is able to reduce the oxygen vacancy concentration due to the combination of Mn2+ and oxygen vacancies in PZT films, forming Mn4+ ions. The interfacial layer between the Pt electrode and PZT films and Mn-doped PZT (x = 4) was detected by measuring the dielectric constant of thin films of different thickness. However, this interfacial layer was not detected in Mn-doped PZT (x = 1). These observations support the concept of the preferential electromigration of oxygen vacancies into sites in planes parallel to the electrodes, which is probably responsible for the hysteretic fatigue.

  2. Zircon Th/U ratios in magmatic environs

    NASA Astrophysics Data System (ADS)

    Kirkland, C. L.; Smithies, R. H.; Taylor, R. J. M.; Evans, N.; McDonald, B.

    2015-01-01

    A comprehensive database of zircon composition in West Australian magmatic rocks reveals negative correlations between both U and Th zircon/whole rock ratio and the zircon saturation temperature, with the observed change with temperature less for U(zircon/whole rock) than for Th(zircon/whole rock). This observation implies a systematic increase in the zircon/rock ratio with falling crystallisation temperature, a result which replicates findings from experimental partition coefficient studies. Under equilibrium conditions there is a trend to lower zircon Th/U with increasing melt temperature which can be attributed to lattice strain. However, within a fractionating magma, Ti-in-zircon temperatures yield the opposite relationship of lower zircon Th/U in cooler melts. This is due to zircon growth under non-equilibrium conditions with greater incompatibility of Th relative to U, and the removal and segregation of mineral precipitates. These observations can be used as a tool to determine whether zircon growth was in a liquid of similar composition to the observed whole rock. We present an equation that estimates the degree of fractionation between the whole rock composition and the zircon parental liquid. This parameter demonstrates the dissimilarity between the liquid from which the zircon grew and the whole rock composition and aids in distinguishing mesostasis growth in fractionated melt versus cumulate growth in less fractionated magma. We use this ratio to investigate zircon growth in igneous rocks of the Musgrave Province. For a suite of c. 1200 Ma magmas that become progressively more fractionated, based on whole rock La/Sm, the fractionation index demonstrates increasing compositional differences between the whole rock and the zircon growth liquid. In the most extreme case independent petrographic evidence indicates mesostasis growth of zircon, whereas in the least fractionated melt zircon growth is established to be close to equilibrium with a zircon saturation temperature of c. 900 °C likely being accurate. In contrast, zircon crystals from a rhyolite of the c. 1070 Ma Giles Supervolcano have distinctive compositional discordances indicative of antecrystic components. The fractionation factor in this rock implies some zircon growth under higher temperature conditions than the whole rock zircon saturation temperature.

  3. The Surface Composition of Titan

    NASA Astrophysics Data System (ADS)

    Clark, R. N.; Pearson, N.; Brown, R. H.; Cruikshank, D. P.; Barnes, J. W.; Jaumann, R.; Soderblom, L. A.; Griffith, C. A.; Rodriguez, S.; Le Mouelic, S.; Lunine, J.; Sotin, C.; Baines, K. H.; Buratti, B. J.; Nicholson, P. D.; Nelson, R.; Stephan, K.

    2011-12-01

    Determining the surface composition of Titan has been inhibited by the lack of spectral properties of potential compounds. We have measured the 0.35 to 5-micron spectral reflectance of a wide range of compounds that might be relevant to Titan and trends are now coming to light with possible spectral matches for classes of materials. While some compounds have been identified and mapped on Titan's surface, such as liquid ethane + methane lakes and benzene, the compounds responsible for the main spectral properties have remained elusive (Clark et al, JGR 2010). Titan's surface is seen in the near infrared in only a few spectral windows, near 0.94, 1.1, 1.3, 1.6, 2.0, 2.68-2.78, and 4.9-5.1 microns in the Cassini Visual and Infrared Mapping Spectrometer (VIMS) spectral range. At shorter wavelengths, UV absorption in the spectra of Titan's haze constrains the surface composition because haze particles settle onto Titan's surface. The average apparent reflectance in the IR windows generally decreases with increasing wavelength except for the 2.7 and 5-micron windows which are at similar levels. The decrease has led researchers to infer a number of compounds responsible for the observed decreasing spectral shape; the most common being water ice. But ice is incompatible with the 2.78/2.68 micron I/F ratio. Many organic compounds have absorptions that are not seen in spectra of Titan, eliminating them as possible major components at the surface, including many polycyclic aromatic hydrocarbons (PAH) previously thought to be compatible with parts of Titan's spectrum. We find that ring compounds similar to benzene rings, but with some C-H bonds replaced by NH have a closer match to Titan's overall spectrum and can explain the relative intensities observed in the spectral windows, including the 2.68 and 2.78-micron double window, the low 3-5 micron reflectance, and increased absorption near 2.1-microns. Key among these compounds that show general properties that match Titan are Cytosine (C4H5N3O), Uracil (C4H4N2O2), Guanine (C5H5N5O), and Adenine (C5H5N5). These compounds are the four nucleobases in the nucleic acid of RNA. If these compounds can be confirmed to be on Titan, their formation pathways may have implications for the formation of life. Other compounds that match features in Titan's spectra include the polycyclic aromatic hydrocarbon (PAH) coronene, consisting of 6 benzene rings. Coronene is also a naturally occurring mineral on Earth, known as karpatite. Combinations of coronene, phenanthene (C14H12), pentacene (C22H14), indole (C8H7N), Cytosine, Uracil, Guanine, and Adenine match the overall spectral structure of Titan spectra. Indole, Cytosine, and Uracil, have 1.5-micron bands that can explain the feature observed in DISR spectra of Titan's surface. These compounds can also help explain the pyrolysis results from the Huygens probe.

  4. Mapping of Titan: Results from the first Titan radar passes

    USGS Publications Warehouse

    Stofan, E.R.; Lunine, J.I.; Lopes, R.; Paganelli, F.; Lorenz, R.D.; Wood, C.A.; Kirk, R.; Wall, S.; Elachi, C.; Soderblom, L.A.; Ostro, S.; Janssen, M.; Radebaugh, J.; Wye, L.; Zebker, H.; Anderson, Y.; Allison, M.; Boehmer, R.; Callahan, P.; Encrenaz, P.; Flamini, E.; Francescetti, G.; Gim, Y.; Hamilton, G.; Hensley, S.; Johnson, W.T.K.; Kelleher, K.; Muhleman, D.; Picardi, G.; Posa, F.; Roth, L.; Seu, R.; Shaffer, S.; Stiles, B.; Vetrella, S.; West, R.

    2006-01-01

    The first two swaths collected by Cassini's Titan Radar Mapper were obtained in October of 2004 (Ta) and February of 2005 (T3). The Ta swath provides evidence for cryovolcanic processes, the possible occurrence of fluvial channels and lakes, and some tectonic activity. The T3 swath has extensive areas of dunes and two large impact craters. We interpret the brightness variations in much of the swaths to result from roughness variations caused by fracturing and erosion of Titan's icy surface, with additional contributions from a combination of volume scattering and compositional variations. Despite the small amount of Titan mapped to date, the significant differences between the terrains of the two swaths suggest that Titan is geologically complex. The overall scarcity of impact craters provides evidence that the surface imaged to date is relatively young, with resurfacing by cryovolcanism, fluvial erosion, aeolian erosion, and likely atmospheric deposition of materials. Future radar swaths will help to further define the nature of and extent to which internal and external processes have shaped Titan's surface. ?? 2006 Elsevier Inc. All rights reserved.

  5. Alpine zircon fission-track ages in the Rhne and Rhine rivers DOWNSTREAM CHANGES OF ALPINE ZIRCON

    E-print Network

    Paris-Sud XI, Université de

    Alpine zircon fission-track ages in the Rhône and Rhine rivers DOWNSTREAM CHANGES OF ALPINE ZIRCON FISSION-TRACK AGES IN THE RH�NE AND RHINE RIVERS MATTHIAS BERNET1, 2 , MARK T. BRANDON1 , JOHN I. GARVER3, Bellingham, Washington, 98225, U.S.A. Keywords: detrital, zircon, fission-track, Rhône River, Rhine River

  6. Titan's Spectacular Volte-Face

    NASA Astrophysics Data System (ADS)

    Griffith, Caitlin A.

    2013-10-01

    Like Earth, Titan sports lakes, storms and rainfall. These features derive from a methane cycle, reminiscent of Earth's hydrological cycle; methane exists as an ice, liquid and gas and transfers between the surface and atmosphere, according to the seasonal weather. Titan's seasons contrast Earth’s. Imagine a summer trip to 70 latitude, where hurricane-sized storms burst forth out of a clear sky every few months for about 15 years. Then they vanish for another 15 years. Envision a trip to the winter polar region. Here the sky is perhaps clear except that the high haze, which filters sunlight like a translucent globe, is somewhat thicker than it is in the summer. Imperceptibly, you are blocking the diffuse organic matter, which is slowly settling out of the hazy orb, and accumulating on the polar surface. These effects are a few of the many that derive from Titan’s circulation and its seasonal changes during the satellite's 29.5 Earth year orbit about the Sun. In particular, and as indicated in recent observations, Titan's circulation flip-flopped. Before equinox in 2009, on average, air rose in the southern polar region and downwelled in the northern polar region. Now the reverse appears to be happening. Here we discuss the observations ranging from the surface to ~500 km altitude that reveal the symphony of responses of Titan's surface and atmosphere to this dramatic shift. In addition we discuss the syntheses of these effects, from theoretical efforts involving microphysical models, local cloud models and general circulation models, with the question of why Titan's seasonal changes are so much more spectacular compared to those of Earth.

  7. Model-Based, Closed-Loop Control of PZT Creep for Cavity Ring-Down Spectroscopy.

    PubMed

    McCartt, A D; Ognibene, T J; Bench, G; Turteltaub, K W

    2014-09-01

    Cavity ring-down spectrometers typically employ a PZT stack to modulate the cavity transmission spectrum. While PZTs ease instrument complexity and aid measurement sensitivity, PZT hysteresis hinders the implementation of cavity-length-stabilized, data-acquisition routines. Once the cavity length is stabilized, the cavity's free spectral range imparts extreme linearity and precision to the measured spectrum's wavelength axis. Methods such as frequency-stabilized cavity ring-down spectroscopy have successfully mitigated PZT hysteresis, but their complexity limits commercial applications. Described herein is a single-laser, model-based, closed-loop method for cavity length control. PMID:25395738

  8. Tidal Winds on Titan Caused by Saturn

    Microsoft Academic Search

    Tetsuya Tokano; Fritz M. Neubauer

    2002-01-01

    The influence of Saturn's gravitational tide on the atmosphere of Titan is investigated by means of a three-dimensional general circulation model. Titan's orbital eccentricity of 0.0292 gives rise to time-dependent radial and librational tide whose potential circles eastward on Titan. Unlike atmospheric tides on terrestrial planets, Saturn's tide on Titan has a large impact on the dynamic meteorology down to

  9. High-current-density electron emission from lead zirconium titanate ferroelectric disc under application of short-duration high-voltage pulses

    Microsoft Academic Search

    Anand Moorti; Prasad Anant Naik; Parshotam Dass Gupta

    2004-01-01

    High-current-density pulsed-electron emission is observed from a poled lead zirconium titanate (PZT, Zr\\/Ti:53\\/47) ferroelectric ceramic disc on application of short-duration (?6 ns) negative high-voltage (?4 kV) pulses. Electron-emission pulses with a peak current density ?400--450 A\\/cm2 and a full-width at half-maximum (FWHM) duration of ?200--250 ns were recorded in the presence of a dc extraction field. These are comparable to

  10. Cathodoluminescence of radiation-induced zircon

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Y.; Nishido, H.; Kayama, M.; Noumi, Y.

    2013-12-01

    Zircon occurs as a common accessory mineral in igneous, metamorphic and sedimentary rocks, and maintains much information on thermal history, metamorphic process and natural radiation dose accumulated in the mineral. U-Pb zircon dating (e.g., SHRIMP) is an important tool to interpret a history of the minerals at a micrometer-scale, where cathodoluminescence (CL) image has been used for identification of internal zones and domains having different chemical compositions and/or structures with a high spatial resolution. The CL of zircon is derived from various types of emission centers, which are derived from impurities such as rare earth elements (REE) and structural defects. In fact, the CL features of zircon are closely related to metamorphic process and radiation from contained radionuclides as well as geochemical condition of its formation. Most zircon has yellow emission, which seems to be assigned to UO2 centers or radiation-induced defect during metamictization of the lattice by alpha particles from the decay of U and Th. In this study, the radiation effects on zircon CL have been studied for He+ ion-implanted samples annealed at various temperatures to clarify radiation-induced defect centers involved with the yellow CL emission in zircon. Single crystals of zircon from Malawi (MZ), Takidani granodiorite (TZ) and Kurobegawa granite (KZ) were selected for He+ ion implantation experiments. The polished plates of the samples were implanted by He+ ion 4.0 MeV corresponding to energy of alpha particle from 238 U and 232Th. CL spectra in the range from 300 to 800 nm with 1 nm step were measured by a scanning electron microscopy-cathodoluminescence (SEM-CL). CL spectra of untreated and annealed zircon show emission bands at ~370 nm assigned to intrinsic defect centers and at ~480, ~580 and ~760 nm to trivalent Dy impurity centers (Cesbron et al., 1995; Gaft et al, 2005). CL emissions in the yellow-region were observed in untreated zircon. The TZ and KZ indicate youngest formation ages of 1.93-1.20 Ma and 1.7-0.9 Ma, respectively (Harayama,1994; Harayama et al., 2010) in the world. In this case, it is hardly to detect yellow CL emissions derived from radiation-induced defect center, suggesting low radiation dose of alpha radiation from 238U and 232Th on them. CL spectra of MZ, TZ and KZ showed an increase in the intensities of yellow emissions with an increase in radiation dose of He+ ion implantation, though He+ ion implantation reduces the intensities of their impurity centers. CL intensity in the yellow region depends on radiation dose of He+ ion implantation. Therefore, if the component of yellow emission could be deconvoluted from the CL spectra in zircon, its intensity will be used for an indicator to evaluate total exposure doses on it during geological age.

  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 funds are raised through the generous support of CSUF parent and family members during fundraising phone

  12. LTA vehicles comparison for Titan exploration

    Microsoft Academic Search

    Giacomo Colombatti; Alessio Aboudan; Nicola La Gloria; Stefano Debei

    2010-01-01

    In the past years several aerial vehicles have been proposed for the exploration of Saturn's largest moon, Titan. After Cassini-Huygens mission, Titan has been revealed as a complex moon with the largest known abundance of organic material in the solar system a part from Earth. Future missions to Titan will carry out an in depth characterisation of the atmosphere, of

  13. Organic chemistry on Titan: Surface interactions

    Microsoft Academic Search

    W. Reid Thompson; Carl Sagan

    1992-01-01

    The interaction of Titan's organic sediments with the surface (solubility in nonpolar fluids) is discussed. How Titan's sediments can be exposed to an aqueous medium for short, but perhaps significant, periods of time is also discussed. Interactions with hydrocarbons and with volcanic magmas are considered. The alteration of Titan's organic sediments over geologic time by the impacts of meteorites and

  14. Sputtering and heating of Titan's upper atmosphere

    E-print Network

    Johnson, Robert E.

    Sputtering and heating of Titan's upper atmosphere BY ROBERT E. JOHNSON 1,2,* 1 University, USA Titan is an important endpoint for understanding atmospheric evolution. Prior to Cassini's arrival ) and dominated by atmospheric sputtering. Recent analysis of the structure of Titan's thermosphere and corona

  15. Dynamics of Titan's thermosphere H. Rishbetha, b,

    E-print Network

    Yelle, Roger V.

    Dynamics of Titan's thermosphere H. Rishbetha, b, *, R.V. Yellea , M. Mendilloa a Center for Space; accepted 23 June 1999 Abstract We estimate the wind speeds in Titan's thermosphere by considering, but in Titan's thermosphere they are mainly controlled by the nonlinear advection and curvature forces

  16. Applicant # Titan Student Centers Governing Board

    E-print Network

    de Lijser, Peter

    Applicant # Titan Student Centers Governing Board 2011-12 Application Packet General Information 1. The Titan Student Centers is a major program operated as part of the Associated Students, CSUF, Incorporated, and an on-campus non-profit organization serving the needs of CSU Fullerton students. The Titan Student

  17. 29 August 2011 2011 TECH TITAN

    E-print Network

    Chiao, Jung-Chih

    29 August 2011 2011 TECH TITAN Media Contact: Herb Booth, Office:817-272-7075, Cell:214 electrical engineering professor, a 2011 Tech Titan in the Technology Innovator category. The council has. The Tech Titans awards are in their 11 year of recognizing outstanding technology companies and North Texas

  18. Imaging of Titan from the Cassini spacecraft

    Microsoft Academic Search

    Carolyn C. Porco; Emily Baker; John Barbara; Kevin Beurle; Andre Brahic; Joseph A. Burns; Sebastien Charnoz; Nick Cooper; Douglas D. Dawson; Anthony D. Del Genio; Tilmann Denk; Luke Dones; Ulyana Dyudina; Michael W. Evans; Stephanie Fussner; Bernd Giese; Kevin Grazier; Paul Helfenstein; Andrew P. Ingersoll; Robert A. Jacobson; Torrence V. Johnson; Alfred McEwen; Carl D. Murray; Gerhard Neukum; William M. Owen; Jason Perry; Thomas Roatsch; Joseph Spitale; Steven Squyres; Peter Thomas; Matthew Tiscareno; Elizabeth P. Turtle; Ashwin R. Vasavada; Joseph Veverka; Roland Wagner; Robert West

    2005-01-01

    Titan, the largest moon of Saturn, is the only satellite in the Solar System with a substantial atmosphere. The atmosphere is poorly understood and obscures the surface, leading to intense speculation about Titan's nature. Here we present observations of Titan from the imaging science experiment onboard the Cassini spacecraft that address some of these issues. The images reveal intricate surface

  19. Titan's Prolific Propane

    NASA Astrophysics Data System (ADS)

    Nixon, C. A.; Jennings, D. E.; Bezard, B.; Teanby, N. A.; Irwin, P. G.; Hewagama, T.; Flaud, J.; Sharpe, S. W.; Coustenis, A.; Flasar, F. M.

    2008-12-01

    Propane (C3H8) was first detected on Titan by the Voyager 1 IRIS spectrometer in 1980, which identified four stratospheric emission bands (?21 at 748 cm-1, ?16 at 922 cm-1, ?15 at 1054 cm-1 and ?7 at 1158 cm-1). Subsequent analyzes of this dataset have largely focused on the strongest of these bands (?21) to infer the VMR (~ 7×10-7 in the stratosphere and relatively uniform with latitude), although it is significantly disadvantaged by being coincident with a strong R-branch line of acetylene. The Composite Infrared Spectrometer (CIRS) onboard Cassini is now providing the most complete infrared mapping of Titan yet obtained. Prior results have included the retrieval of the vertical and latitudinal profiles of minor gas species, including propane, again exclusively via the ?21 band, the only band for which a linelist is publicly available. We present new modeling of CIRS low-latitude limb spectra acquired from 2004 to 2008. The residuals after modeling all gases except propane clearly show all four bands detected by IRIS, now at much higher signal to noise. In addition, we show that four further bands are clearly evident once the emissions of methane (CH4) and ethane (C2H6) have been modeled and subtracted out: ?8 at 869 cm-1, ?14 at 1338 cm-1, ?13 at 1376 cm-1 and ?19 at 1472 cm-1). Using a new line list for the bands in the range 1300 to 1500 cm-1, we model the ?14, ?13 and ?19 emission bands and compare to abundances retrieved using the ?21 at 748 cm-1. This work has several purposes. Firstly, we demonstrate the urgent need for laboratory spectroscopic measurements of the propane bands at 869, 922, 1054 and 1158 cm-1 leading to line strength listings suitable for spectral calculations. Secondly, we show that the current line list for the 748 cm-1 band does not fit the data accurately, and requires a new spectroscopic study. Finally, we discuss the possibility of new gaseous molecular detections in the regions dominated by these ubiquitous propane bands, once they can be properly modeled.

  20. Ti in zircon from the Boggy Plain zoned pluton: implications for zircon petrology and Hadean tectonics

    NASA Astrophysics Data System (ADS)

    Ickert, R. B.; Williams, I. S.; Wyborn, D.

    2011-08-01

    The understanding of zircon crystallization, and of the Ti-in-zircon thermometer, has been enhanced by Ti concentration measurements of zircon from a small, concentrically zoned pluton in south-eastern Australia, the Boggy Plain zoned pluton (BPZP). Zircon crystals from rocks ranging in composition from gabbro to aplite were analysed for U-Th-Pb dating and Ti concentrations by an ion microprobe. Geochronological data yield a 206Pb/238U age of 417.2 ± 2.0 Ma (95% confidence) and demonstrate the presence of older inherited or xenocrystic zircon. Titanium measurements ( n = 158) yield a mean Ti concentration of 11.7 ± 6.1 ppm (2SD) which corresponds to a mean crystallization temperature of 790°C for an ?-TiO2 = 0.74 (estimated using mineral equilibria), or 760°C for an ?-TiO2 = 1.0. Apparent zircon crystallization temperatures are similar in all intrusive phases, although the gabbro yields slightly higher values, indicating that crystallization occurred at the same temperature in all rock types. This finding is consistent with previous work on the BPZP, which indicates that liquid-crystal sorting (crystal fractionation) was the dominant control on chemical differentiation, and that late, differentiated liquids were similar in composition for all rock types. A simple forward model approximately predicts the range of crystallization temperatures, but not the shape of the distributions, due to sampling biases and complexities in the cooling and crystallization history of the pluton. The distribution of Ti concentrations has a mode at a higher Ti (higher temperature) than the sample set of Hadean detrital zircon. This is consistent with the hypothesis that the skew to low-T in the Hadean dataset is due to the presence of zircon that crystallized from wet anatectic melts.

  1. Electrical power generation characteristics of PZT piezoelectric ceramics.

    PubMed

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

    1998-01-01

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

  2. Ti-in-zircon thermometry: applications and limitations

    NASA Astrophysics Data System (ADS)

    Fu, Bin; Page, F. Zeb; Cavosie, Aaron J.; Fournelle, John; Kita, Noriko T.; Lackey, Jade Star; Wilde, Simon A.; Valley, John W.

    2008-08-01

    The titanium concentrations of 484 zircons with U-Pb ages of ˜1 Ma to 4.4 Ga were measured by ion microprobe. Samples come from 45 different igneous rocks (365 zircons), as well as zircon megacrysts (84) from kimberlite, Early Archean detrital zircons (32), and zircon reference materials (3). Samples were chosen to represent a large range of igneous rock compositions. Most of the zircons contain less than 20 ppm Ti. Apparent temperatures for zircon crystallization were calculated using the Ti-in-zircon thermometer (Watson et al. 2006, Contrib Mineral Petrol 151:413-433) without making corrections for reduced oxide activities (e.g., TiO2 or SiO2), or variable pressure. Average apparent Ti-in-zircon temperatures range from 500° to 850°C, and are lower than either zircon saturation temperatures (for granitic rocks) or predicted crystallization temperatures of evolved melts (˜15% melt residue for mafic rocks). Temperatures average: 653 ± 124°C (2 standard deviations, 60 zircons) for felsic to intermediate igneous rocks, 758 ± 111°C (261 zircons) for mafic rocks, and 758 ± 98°C (84 zircons) for mantle megacrysts from kimberlite. Individually, the effects of reduced a_{TiO2} or a_{SiO2}, variable pressure, deviations from Henry’s Law, and subsolidus Ti exchange are insufficient to explain the seemingly low temperatures for zircon crystallization in igneous rocks. MELTs calculations show that mafic magmas can evolve to hydrous melts with significantly lower crystallization temperature for the last 10-15% melt residue than that of the main rock. While some magmatic zircons surely form in such late hydrous melts, low apparent temperatures are found in zircons that are included within phenocrysts or glass showing that those zircons are not from evolved residue melts. Intracrystalline variability in Ti concentration, in excess of analytical precision, is observed for nearly all zircons that were analyzed more than once. However, there is no systematic change in Ti content from core to rim, or correlation with zoning, age, U content, Th/U ratio, or concordance in U-Pb age. Thus, it is likely that other variables, in addition to temperature and a_{TiO2}, are important in controlling the Ti content of zircon. The Ti contents of igneous zircons from different rock types worldwide overlap significantly. However, on a more restricted regional scale, apparent Ti-in-zircon temperatures correlate with whole-rock SiO2 and HfO2 for plutonic rocks of the Sierra Nevada batholith, averaging 750°C at 50 wt.% SiO2 and 600°C at 75 wt.%. Among felsic plutons in the Sierra, peraluminous granites average 610 ± 88°C, while metaluminous rocks average 694 ± 94°C. Detrital zircons from the Jack Hills, Western Australia with ages from 4.4 to 4.0 Ga have apparent temperatures of 717 ± 108°C, which are intermediate between values for felsic rocks and those for mafic rocks. Although some mafic zircons have higher Ti content, values for Early Archean detrital zircons from a proposed granitic provenance are similar to zircons from many mafic rocks, including anorthosites from the Adirondack Mts (709 ± 76°C). Furthermore, the Jack Hills zircon apparent Ti-temperatures are significantly higher than measured values for peraluminous granites (610 ± 88°C). Thus the Ti concentration in detrital zircons and apparent Ti-in-zircon temperatures are not sufficient to independently identify parent melt composition.

  3. Self-induced fracture generation in zircon

    Microsoft Academic Search

    James K. W. Lee; Jeroen Tromp

    1995-01-01

    The mineral zircon has particular geological significance because of its use in the age determination of rocks and as a structural analogue phase for radioactive waste forms. Despite its widespread utility, however, radiation damage of the crystal structure (metamictization) causes a volume expansion of the crystal lattice and the generation of internal stresses which can induce fractures in the crystal.

  4. Micropatterned lead zirconium titanate thin films

    Microsoft Academic Search

    M. Ozenbas

    Micropatterning of Pb(Zr0.52Ti0.48)O3 (PZT) thin films with line features as small as 350 nm was demonstrated through capillary molding of organometallic solutions within the continuous channels of an elastomeric mold. Despite the large stresses that develop during the evaporation of the solvent, pyrolysis of the organics, and the densification and crystallization of the inorganic gel, the patterned crystalline PZT films

  5. Active buckling control of smart plate as diaphragm with PZT5 sensor/actuator patches

    NASA Astrophysics Data System (ADS)

    Viliani, N. S.; Pourrostami, H.; Mostafavi, S. M.; Hashemizadeh, F.; Safian, M. R.; Hashemi, M.

    2014-12-01

    In current study, buckling analyses of smart plate is presented. The various types of piezoelectric materials are under investigation for petrochemical industry and other applications. The PZT sensor output is used to determine the input to the PZT actuator using the feedback control algorithm for buckling control of FG plate. This study investigated the governing differential equations of motion of smart plate which includes FG plate as the membrane and PZT5 patches as actuator and sensor. The Fourier series method adopted to obtain the solution for the equation of motion. Also the effects of feedback gain and FGM volume fraction exponent on the critical buckling load for PZT-5A are studied. The potential application of current study can be found in optimal design of sensor's diaphragm. The variation of critical buckling load vs. feedback gain indicates that by increasing the feedback gain, the buckling load increases.

  6. Cosmic Dust Detector Using Piezoelectric PZT with Current-to-Voltage Conversion Amplifier

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.; Miyachi, T.; Nakamura, M. H.

    2012-03-01

    This paper describes the concept of a dust monitor with a large detection area but less resource using PZT ceramics, and the possibility is experimentally demonstrated. We suggested the use of a current-to-voltage converting amplifier for it.

  7. Micro-Machined High-Frequency (80 MHz) PZT Thick Film Linear Arrays

    PubMed Central

    Zhou, Qifa; Wu, Dawei; Liu, Changgeng; Zhu, Benpeng; Djuth, Frank; Shung, K. Kirk

    2010-01-01

    This paper presents the development of a micro-machined high-frequency linear array using PZT piezoelectric thick films. The linear array has 32 elements with an element width of 24 ?m and an element length of 4 mm. Array elements were fabricated by deep reactive ion etching of PZT thick films, which were prepared from spin-coating of PZT solgel composite. Detailed fabrication processes, especially PZT thick film etching conditions and a novel transferring-and-etching method, are presented and discussed. Array designs were evaluated by simulation. Experimental measurements show that the array had a center frequency of 80 MHz and a fractional bandwidth (?6 dB) of 60%. An insertion loss of ?41 dB and adjacent element crosstalk of ?21 dB were found at the center frequency. PMID:20889407

  8. Single mode Lamb wave phased array beamforming with hybrid PZT-SLDV sensing

    NASA Astrophysics Data System (ADS)

    Tian, Zhenhua; Yu, Lingyu

    2014-04-01

    This paper presents a single Lamb mode phased array beamforming by using a hybrid piezoelectric transducer (PZT)-scanning laser Doppler vibrometer (SLDV) system. The array system consists of a surface mounted PZT to generate Lamb waves and a non-contact SLDV to acquire high spatial resolution time-space wavefield remotely. The time-space wavefield contains Lamb waves which can be generated from the PZT excitation, damage scattering, mode conversion, etc. A frequency-wavenumber (f-k) decomposition technique is used to decompose the miscellaneous Lamb waves into individual wave mode components and wave propagations in different directions. The f-k decomposition allows using a single wave component as the phased array input for beamforming. The single mode array beamforming methodology was verified through PZT-SLDV experimental tests on an aluminum plate with a bonded quartz rod as a simulated damage

  9. 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.

  10. Fabrication and Characterization of PZT Thin-Film on Bulk Micromachined Si Motion Detectors

    SciTech Connect

    Clem, P.; Garino, T.J.; Laguna, G.; Tuttle, B.A.

    1999-01-07

    Motion detectors consisting of Pb(Zr{sub x}Ti{sub (1{minus}x)})O{sub 3} (PZT) thin films, between platinum electrodes, on micromachined silicon compound clamped-clamped or cantilever beam structures were fabricated using either hot KOH or High Aspect Ratio Silicon Etching (HARSE) to micromachine the silicon. The beams were designed such that a thicker region served as a test mass that produced stress at the top of the membrane springs that supported it when the object to which the detector was mounted moved. The PZT film devices were placed on these membranes to generate a charge or a voltage in response to the stress through the piezoelectric effect. Issues of integration of the PZT device fabrication process with the two etching processes are discussed. The effects of PZT composition and device geometry on the response of the detectors to motion is reported and discussed.

  11. Airflow energy harvesters of metal-based PZT thin films by self-excited vibration

    NASA Astrophysics Data System (ADS)

    Suwa, E.; Tsujiura, Y.; Kurokawa, F.; Hida, H.; Kanno, I.

    2014-11-01

    We developed self-excited vibration energy harvesters of Pb(Zr,Ti)O3 (PZT) thin films using airflow. To enhance the self-excited vibration, we used 30-?m-thick stainless steel (SS304) foils as base cantilevers on which PZT thin films were deposited by rf-magnetron sputtering. To compensate for the initial bending of PZT/SS304 unimorph cantilever due to the thermal stress, we deposited counter PZT thin films on the back of the SS304 cantilever. We evaluated power-generation performance and vibration mode of the energy harvester in the airflow. When the angle of attack (AOA) was 20° to 30°, large vibration was generated at wind speeds over 8 m/s. By FFT analysis, we confirmed that stable self-excited vibration was generated. At the AOA of 30°, the output power reached 19 ?W at wind speeds of 12 m/s.

  12. Charged particles in Titan's ionosphere

    NASA Astrophysics Data System (ADS)

    Tripathi, Sachchida

    2010-05-01

    Charged particles in Titan's ionosphere Marykutty Michael1, Sachchida Nand Tripathi1,2,3, Pratima Arya1 1Indian Institute of Technology Kanpur 2Oak Ridge Associated Universities 3NASA Goddard Space Flight Center Observations by two instruments onboard the Cassini spacecraft, Ion Neutral Mass Spectrometer (INMS) and CAssini Plasma Spectrometer (CAPS), revealed the existence of heavy hydrocarbon and nitrile species with masses of several thousand atomic mass units at altitudes of 950 - 1400 km in the atmosphere of Titan (Waite et al., 2007; Crary et al., 2009). Though these particles were believed to be molecules, they are most likely aerosols formed by the clumping of smaller molecules (Waite et al., 2009). These particles were estimated to have a density of 10-3 kg m-3 and a size of up to 256 nm. The existence of very heavy ions has also been observed by the CAPS components with a mass by charge ratio of up to 10000 (Coates et al., 2007, 2009; Sittler et al., 2009). The goal of this paper is to find out whether the so called heavy ions (or charged particles) are generated by the charge transfer of ions and electrons to the particles. The charging of these particles has been studied by using the charge balance equations that include positive ions, negative ions, electrons, neutral and charged particles. Information on the most abundant ion clusters are obtained from Vuitton et al., (2009) and Wilson and Atreya, (2004). Mass by charge ratio thus calculated will be compared with those observed by Coates et al. (2007). References: Coates AJ, et al., Discovery of heavy negative ions in Titan's ionosphere, Geophys. Res. Lett., 34:L22103, 2007. Coates AJ, et al., Heavy negative ions in titan's ionosphere: altitude and latitude dependence. Planet. Space Sci., doi:10.1016/j.pss.2009.05.009, 2009. Crary F.J., et al., Heavy ions, temperatures and winds in titan's ionosphere: Combined cassini caps and inms observations. Planet. Space Sci., doi:10.1016/j.pss.2009.09.006, 2009. Sittler,E.C. et al., Heavy ion formation in Titan's ionosphere: Magnetospheric introduction of free oxygen and a source of Titan's aerosols? Planet. Space Sci., doi:10.1016/j.pss.2009.07.017, 2009. Vuitton, V., Negative ion chemistry in Titan's upper atmosphere, Planet. Space Sci., doi:10.1016/j.pss.2009.04.004, 2009. Waite J.H, et al., The process of tholin formation in Titan's upper atmosphere. Science, doi: 10.1126/science.1139727, 316, 870, 2007. Waite JH, et al., High altitude production of Titan's aerosols, In Titan from Cassini-Huygens, edited by RH. Brown, J.P Lebreton, JH Waite, Springer, 2009. Wilson, E.H. and S. Atreya, Current state of modeling the photochemistry of Titan's mutually dependent atmosphere and ionosphere, J. Geophys. Res., 109, E06002, doi:10.1029/2003JE002181, 2004.

  13. Subterahertz excitations and magnetoelectric effects in hexaferrite-piezoelectric bilayers

    SciTech Connect

    Ustinov, Alexey B. [Department of Physics, Oakland University, Rochester, Michigan 48309 (United States); Department of Physical Electronics and Technology, St. Petersburg Electrotechnical University, St. Petersburg 197376 (Russian Federation); Srinivasan, G. [Department of Physics, Oakland University, Rochester, Michigan 48309 (United States)

    2008-10-06

    A frequency-agile hexaferrite-piezoelectric composite for potential device applications at subterahertz frequencies is studied. The bilayer is composed of aluminum substituted barium hexagonal ferrite (BaAl{sub 2}Fe{sub 10}O{sub 19}) and lead zirconate titanate (PZT). A dc electric field applied to PZT results in mechanical deformation of the ferrite, leading to a frequency shift in ferromagnetic resonance. The bilayer demonstrates magnetoelectric interaction coefficient of about 0.37 Oe cm/kV.

  14. Design and fabrication of a micro PZT cantilever array actuator for applications in fluidic systems

    Microsoft Academic Search

    Hyonse Kim; Gilho Yoon; Jongwon Kim

    2005-01-01

    In this article, a micro cantilever array actuated byPZT films is designed and fabricated for micro fluidic systems. The design features for maximizing tip deflections and minimizing\\u000a fluid leakage are described. The governing equation of the composite PZT cantilever is derived and the actuating behavior\\u000a predicted. The calculated value of the tip deflection was 15 µm at 5 V. The

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

    Microsoft Academic Search

    L Burianová; M Šulc; M Prokopová

    2001-01-01

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

  16. Nanoscale Effects on Structural and Giant Dielectric of PZT Synthesized by High Energy Ball Mill

    Microsoft Academic Search

    S. K. S. Parashar; Kajal Parashar

    2010-01-01

    We report the formation of nanostructure Pb(Zr0.53Ti0.47)O3 (PZT) ceramic powder having cubic crystal structure under ambient conditions that has been found to be stable up to 800°C. The cubic structure of nanocrystalline PZT under normal condition is attributed to the crystallite size effect. The crystallite size effect has also reflected its crucial role in substantial enhancement of the dielectric permittvity

  17. Health monitoring of a continuous rigid frame bridge based on PZT impedance and strain measurements

    NASA Astrophysics Data System (ADS)

    Zhang, Junbing; Zhu, Hongping; Wang, Dansheng; He, Bo; Zhou, Huaqiang

    2009-07-01

    Critical civil infrastructures such as bridges, dams, and pipelines present a major investment and their safety and security affect the life of citizens and national economic development. So it is very important for engineers and researchers to monitor their integrity while in operation and throughout. In recent years, the piezoelectric-ceramic (PZT) patches, which serve both as impedance sensors and actuators, have been increasingly used for structural health monitoring. This paper presents an impedance-based method, which utilizes the electro-mechanical coupling property of PZT sensors. There are a lot of advantages of this method, such as not based on any physical models, sensitive to tiny damage for its high frequency characteristics. An engineering application of this method for health monitoring of a continuous rigid frame bridge is implemented in this study. Some PZT active sensors are embedded into critical sections of the continuous rigid-frame box beam. The electrical admittances of these distributed PZT sensors are measured when the bridge is constructing or suffering from operational loads. For comparison, strain gauges are arranged in adjacent regions of these PZT sensors to obtain the strains of concrete around them at the same time. Based on the admittance sigatures obtained form PZT sensors and the strain measurements of concrete around them, the health status of the bridge is monitored and evaluated successfully.

  18. Numerical analysis of PZT rebar active sensing system for structural health monitoring of RC structure

    NASA Astrophysics Data System (ADS)

    Wu, F.; Yi, J.; Li, W. J.

    2014-03-01

    An active sensing diagnostic system for reinforced concrete SHM has been under investigation. Test results show that the system can detect the damage of the structure. To fundamentally understand the damage algorithm and therefore to establish a robust diagnostic method, accurate Finite Element Analysis (FEA) for the system becomes essential. For the system, a rebar with surface bonded PZT under a transient wave load was simulated and analyzed using commercial FEA software. A detailed 2D axi-symmetric model for a rebar attaching PZT was first established. The model simulates the rebar with wedges, an epoxy adhesive layer, as well as a PZT layer. PZT material parameter transformation with high order tensors was discussed due to the format differences between IEEE Standard and ANSYS. The selection of material properties such as Raleigh damping coefficients was discussed. The direct coupled-field analysis type was selected during simulation. The results from simulation matched well with the experimental data. Further simulation for debonding damage detection for concrete beam with the PZT rebar has been performed. And the numerical results have been validated with test results too. The good consistency between two proves that the numerical models were reasonably accurate. Further system optimization has been performed based on these models. By changing PZT layout and size, the output signals could be increased with magnitudes. And the damage detection signals have been found to be increased exponentially with the debonding size of the rebar.

  19. Strain mediated coupling in magnetron sputtered multiferroic PZT/Ni-Mn-In/Si thin film heterostructure

    SciTech Connect

    Singh, Kirandeep; Kaur, Davinder, E-mail: dkaurfph@iitr.ernet.in [Functional Nanomaterials Research Lab, Department of Physics and Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee-247667, Uttarakhand (India); Singh, Sushil Kumar [Functional Materials Division, Solid State Physics Lab (SSPL), DRDO, Lucknow Road, Timarpur, Delhi 110054 (India)

    2014-09-21

    The strain mediated electrical and magnetic properties were investigated in PZT/Ni-Mn-In heterostructure deposited on Si (100) by dc/rf magnetron sputtering. X-ray diffraction pattern revealed that (220) orientation of Ni-Mn-In facilitate the (110) oriented tertragonal phase growth of PZT layer in PZT/Ni-Mn-In heterostructure. A distinctive peak in dielectric constant versus temperature plots around martensitic phase transformation temperature of Ni-Mn-In showed a strain mediated coupling between Ni-Mn-In and PZT layers. The ferroelectric measurement taken at different temperatures exhibits a well saturated and temperature dependent P-E loops with a highest value of P{sub sat}???55 ?C/cm{sup 2} obtained during martensite-austenite transition temperature region of Ni-Mn-In. The stress induced by Ni-Mn-In layer on upper PZT film due to structural transformation from martensite to austenite resulted in temperature modulated Tunability of PZT/Ni-Mn-In heterostructure. A tunability of 42% was achieved at 290?K (structural transition region of Ni-Mn-In) in these heterostructures. I-V measurements taken at different temperatures indicated that ohmic conduction was the main conduction mechanism over a large electric field range in these heterostructures. Magnetic measurement revealed that heterostructure was ferromagnetic at room temperature with a saturation magnetization of ?123?emu/cm{sup 3}. Such multiferroic heterostructures exhibits promising applications in various microelectromechanical systems.

  20. Evolution of linear moduli and remnant state variables during polarization reversal in a lead zirconate rectangular parallelpiped at room and high temperatures

    NASA Astrophysics Data System (ADS)

    Ji, Dae Won; Kim, Sang-Joo

    2014-12-01

    A poled lead titanate zirconate rectangular parallelepiped is subjected to electric field pulses with gradually increasing magnitude at room and high temperatures. From measured electric displacement and strain responses, permittivity and piezoelectric coefficients are estimated and plotted with respect to remnant polarization. Equations for piezoelectric coefficients are proposed as functions of relative remnant polarization and temperature. The so-called reference remnant polarization and strains are calculated from measured remnant polarization and strains. Reference remnant strains are plotted with respect to reference remnant polarization, and their evolutions during polarization reversal are analyzed and compared.

  1. Enhanced ferroelectric loop asymmetry of lead zirconate titanate thin films under nanoindentation

    NASA Astrophysics Data System (ADS)

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

    2007-01-01

    The effect of mechanical stress on the local switching behavior and hysteresis properties of Pb(Zr ,Ti)O3 and Mn-doped Pb(Zr ,Ti)O3 ferroelectric thin films has been studied using spherical nanoindentation. A conductive WC-Co cermet indenter tip of 500?m nominal radius was employed in a modified nanoindentation system to allow the simultaneous application of driving voltage and mechanical loading, and consequently to collect the ferroelectric charge developed on thin films without a top electrode. Instrumented progressive indentation caused an enhancement of hysteresis loop deformations. The charge released versus applied voltage (Q-V) hysteresis loops gradually shifted along the voltage axis with increasing indentation force. Also, an enhanced vertical shift and hysteresis gap of the Q-V loops was observed. The parameter of horizontal loop asymmetry (? ) increased almost linearly with the force by an increment of about (0.4-0.5)×10-3/100mN with a 50V peak drive voltage and a 50Hz sinusoidal wave form. The effect of nanoindentation on polarization reversal in thin ferroelectric films is suggested to result from a variation in residual stress state, asymmetric distribution of charged defects, and asymmetric lattice distortion produced by the inhomogeneous indentation stress field.

  2. Nonaqueous solution synthesis process for preparing oxide powders of lead zirconate titanate and related materials

    DOEpatents

    Voigt, James A. (Corrales, NM); Sipola, Diana L. (Albuquerque, NM); Tuttle, Bruce A. (Albuquerque, NM); Anderson, Mark T. (Woodbury, MN)

    1999-01-01

    A process for producing powders of perovskite-type compounds which comprises mixing a metal alkoxide solution with a lead acetate solution to form a homogeneous, clear metal solution, adding an oxalic acid/n-propanol solution to this metal solution to form an easily filterable, free-flowing precursor powder and then calcining this powder. This process provides fine perovskite-phase powders with ferroelectric properties which are particularly useful in a variety of electronic applications.

  3. Nonaqueous solution synthesis process for preparing oxide powders of lead zirconate titanate and related materials

    DOEpatents

    Voigt, J.A.; Sipola, D.L.; Tuttle, B.A.; Anderson, M.T.

    1999-06-01

    A process is disclosed for producing powders of perovskite-type compounds which comprises mixing a metal alkoxide solution with a lead acetate solution to form a homogeneous, clear metal solution, adding an oxalic acid/n-propanol solution to this metal solution to form an easily filterable, free-flowing precursor powder and then calcining this powder. This process provides fine perovskite-phase powders with ferroelectric properties which are particularly useful in a variety of electronic applications. 4 figs.

  4. Characterization of lead zirconate titanate piezoceramic using high frequency ultrasonic spectroscopy

    E-print Network

    Cao, Wenwu

    spectroscopy Haifeng Wang, Wenhua Jiang,a) and Wenwu Caob) Materials Research Laboratory, National Resource Center for Medical Ultrasonic Transducer Engineering, The Pennsylvania State University, University Park of water-piezoelectric ceramic. The incident directions of the wave were chosen to be appropriate

  5. Magnetoelectric composite materials based on lead zirconate titanate and nickel ferrite

    SciTech Connect

    Lupeiko, T.G.; Lopatin, S.S.; Lisnevskaya, I.V.; Zvyagintsev, B.I. [Rostov State Univ., Rostov-na-Donu (Russian Federation)

    1994-11-01

    Composite materials that consist of a piezoelectric phase and a magnetostrictive ferrite exhibit a magnetoelectric effect. In composites, this effect is a consequence of the collective mechanical interaction of phases, and it manifests itself via electrical polarization or magnetization in magnetic or electric fields. At present, magnetoelectric composites are more promising materials than single-phase magnetoelectrics; most of the latter exhibit magnetoelectric properties at temperatures of liquid helium or nitrogen. For the best single-phase ferromagnet Cr{sub 2}O{sub 3}, the magnetoelectric conversion factor if {Delta}E/{Delta}H = 25 x 10{sup {minus}3} V/A; the largest {Delta}E/{Delta}H ratios that were achieved for magnetoelectric ceramic materials prepared from powders of BaTiO{sub 3} and Ni{sub 0.97}Co{sub 0.03}Mn{sub 0.1}Fe{sub 1.9}O{sub 4} ferrite and for composites of the BaO-TiO{sub 2}-CoO-Fe{sub 2}O{sub 3} system prepared by unidirectional solidification of eutectic melts are 100 x 10{sup {minus}3} and 163 x 10{sup {minus}3} V/A, respectively. In addition to high {Delta}E/{Delta}H values, composites offer material designers the possibility of adjusting their piezoelectric and magnetostrictive components and of varying the ratios of these components over a wide range. This enables the design of magnetoelectric materials with controlled properties. In this paper, the authors report on the electrophysical and magnetoelectric properties of composites based on LZT and modified nickel ferrite and doped with bismuth, lanthanum, and niobium oxides.

  6. Effect of composition and preparation conditions on the microstructure of lead zirconate titanate films

    NASA Astrophysics Data System (ADS)

    di Cristoforo, A.; Mengucci, P.; Majni, G.; Severi, M.; Guerri, S.; Watts, B. E.; Leccabue, F.; Seuret, D.

    1996-10-01

    The crystallization behaviour of thin films of composition Pb 1.1Zr xTi 1 - xO 3, where x = 0.75 and 0.25, prepared by a sol-gel route, have been studied using grazing angle X-ray diffraction and transmission electron microscopy. The X-ray diffraction was done at different incident angles and revealed different structures as the penetration into the film increased. Titanium-rich films were mainly perovskite with titanium oxide that may have formed within the film during its crystallization. The pyrochlore phase in the zirconium-rich film is more evident near the surface; this is also confirmed by microscopy of the film in cross section. In addition, an irregular distribution of the titanium, used as the adhesion layer was also seen on the micrographs. The electrical measurements evidence some correlation with the micro-structure observed.

  7. 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

  8. Campus Contacts Titan Bookstore Cafe

    E-print Network

    de Lijser, Peter

    @ 5pm-6pm ­ Titan Resume Builder Workshop (IRVC-121) Monday, March 18th @ 5pm-6pm ­ Networking Tips in your course receiving Disabled Student Services, please take a few moments to review the DSS registration and testing process at the CSUF, Irvine Campus. 1. Studen

  9. Crystallization of amorphous bismuth titanate

    Microsoft Academic Search

    Seiji Kojima; Anwar Hushur; Fuming Jiang; Sinichi Hamazaki; Masaaki Takashige; Min-Su Jang; Shiro Shimada

    2001-01-01

    We studied the transformation of amorphous bismuth titanate by heat treatments. After an as-quenched amorphous sample was annealed at 500 °C, the lowest Raman peak became intense like a boson peak for glass. This fact indicates the formation of intermediate range order. The medium range correlation length of 7 nm calculated from the boson peak frequency is in agreement with

  10. Seasonal changes in Titan's meteorology

    NASA Astrophysics Data System (ADS)

    Turtle, E. P.; Del Genio, A. D.; Barbara, J. M.; Perry, J. E.; Schaller, E. L.; McEwen, A. S.; West, R. A.; Ray, T. L.

    2011-02-01

    The Cassini Imaging Science Subsystem has observed Titan for ˜1/4 Titan year, and we report here the first evidence of seasonal shifts in preferred locations of tropospheric methane clouds. South-polar convective cloud activity, common in late southern summer, has become rare. North-polar and northern mid-latitude clouds appeared during the approach to the northern spring equinox in August 2009. Recent observations have shown extensive cloud systems at low latitudes. In contrast, southern mid-latitude and subtropical clouds have appeared sporadically throughout the mission, exhibiting little seasonality to date. These differences in behavior suggest that Titan's clouds, and thus its general circulation, are influenced by both the rapid temperature response of a low-thermal-inertia surface and the much longer radiative timescale of Titan's cold thick troposphere. North-polar clouds are often seen near lakes and seas, suggesting that local increases in methane concentration and/or lifting generated by surface roughness gradients may promote cloud formation.

  11. GCM Simulations of Titan's Paleoclimate

    NASA Astrophysics Data System (ADS)

    Lora, Juan M.; Lunine, Jonathan; Russell, Joellen; Hayes, Alexander

    2014-11-01

    The hemispheric asymmetry observed in the distribution of Titan's lakes and seas has been suggested to be the result of asymmetric seasonal forcing, where a relative moistening of the north occurs in the current epoch due to its longer and less intense summers. General circulation models (GCMs) of present-day Titan have also shown that the atmosphere transports methane away from the equator. In this work, we use a Titan GCM to investigate the effects that changes in Titan's effective orbital parameters have had on its climate in recent geologic history. The simulations show that the climate is relatively insensitive to changes in orbital parameters, with persistently dry low latitudes and wet polar regions. The amount of surface methane that builds up over either pole depends on the insolation distribution, confirming the influence of orbital forcing on the distribution of surface liquids. The evolution of the orbital forcing implies that the surface reservoir must be transported on timescales of ~30 kyr, in which case the asymmetry reverses with a period of ~125 kyr. Otherwise, the orbital forcing is insufficient for generating the observed dichotomy.

  12. The organic aerosols of Titan.

    PubMed

    Khare, B N; Sagan, C; Thompson, W R; Arakawa, E T; Suits, F; Callcott, T A; Williams, M W; Shrader, S; Ogino, H; Willingham, T O; Nagy, B

    1984-01-01

    A dark reddish organic solid, called tholin, is synthesized from simulated Titanian atmospheres by irradiation with high energy electrons in a plasma discharge. The visible reflection spectrum of this tholin is found to be similar to that of high altitude aerosols responsible for the albedo and reddish color of Titan. The real (n) and imaginary (k) parts of the complex refractive index of thin films of Titan tholin prepared by continuous D.C. discharge through a 0.9 N2/0.1 CH4 gas mixture at 0.2 mb is determined from x-ray to microwave frequencies. Values of n (approximately equal to 1.65) and k (approximately equal to 0.004 to 0.08) in the visible are consistent with deductions made by ground-based and spaceborne observations of Titan. Many infrared absorption features are present in k (lambda), including the 4.6 micrometers nitrile band. Molecular analysis of the volatile component of this tholin was performed by sequential and non-sequential pyrolytic gas chromatography/mass spectrometry. More than one hundred organic compounds are released; tentative identifications include saturated and unsaturated aliphatic hydrocarbons, substituted polycyclic aromatics, nitriles, amines, pyrroles, pyrazines, pyridines, pyrimidines, and the purine, adenine. In addition, acid hydrolysis produces a racemic mixture of biological and non-biological amino acids. Many of these molecules are implicated in the origin of life on Earth, suggesting Titan as a contemporary laboratory environment for prebiological organic chemistry on a planetary scale. PMID:11537796

  13. Photochemical Modeling of Titan's Atmosphere

    Microsoft Academic Search

    D. Toublanc; J. P. Parisot; J. Brillet; D. Gautier; F. Raulin; C. P. McKay

    1995-01-01

    We have developed a new photochemical model of Titan's atmosphere which includes all the important compounds and reactions in spherical geometry from the surface to 1240 km. Compared to the previous model of Yung et al. (1984, Astrophys. J. Suppl. 55, 465-506), the most significant recent change in the reactions used is the updated methane photodissociation scheme (Mordaunt et al.

  14. Computer modelling of barium titanate

    Microsoft Academic Search

    G. V. Lewis; C. R. A. Catlow

    1983-01-01

    Barium titanate is an important material for both scientific and industrial applications. Much of the interest centres around its ferroelectric properties, since it is structurally the most simple in this class. In addition rare-earth doped ceramics are found to exhibit a very steep positive temperature coefficient of resistance (PTCR) above the Curie point. The theory of this PTCR effect is

  15. PZT active health monitoring for fatigue accumulative damage of concrete beam containing nano-particles for pavement

    Microsoft Academic Search

    Mao-hua Zhang; Hui Li; Jin-ping Ou

    2007-01-01

    Based on the actuation and sense function of piezoceramic materials, PZT active health monitoring for fatigue accumulative damage of concrete beam containing nano-particles (TiO2) for pavement is experimentally studied. The test results indicate that the vibration signals received by PZT patches have three development stages obviously: the damage-formation stage, the damage-steady-growth stage and the damage-sharp-growth stage, which shows that PZT

  16. Hafnium isotopic heterogeneity in zircons from granitic rocks: Geochemical evaluation and modeling of “zircon effect” in crustal anatexis

    NASA Astrophysics Data System (ADS)

    Tang, Ming; Wang, Xiao-Lei; Shu, Xu-Jie; Wang, Di; Yang, Tao; Gopon, Phillip

    2014-03-01

    We carried out a geochemical evaluation and modeled the mechanism responsible for varied Hf isotopic ratios in magmatic zircons of a single granitic rock specimen. Five representative granitic samples were selected from southern China based on preliminary Hf isotopic data. Our new dataset of zircon Hf isotopes confirmed significant Hf-isotope variations (5-9 epsilon units) for each sample, and these zircons show roughly positive Th/U versus T (crystallizing temperature) correlations, while the Lu/Hf variation is independent from T. In addition, some zircons show significantly higher Ti concentrations in the rims compared to the interiors, implying reverse thermal zonation based on the Ti-in-zircon thermometry. These geochemical features in zircons suggest open-system processes which may have resulted from frequent replenishment. We modeled zircon dissolution during crustal anatexis to reveal the Hf isotopic evolution in the extracted melts. The model suggests that the extracted melts may have extremely variable Hf isotope compositions (>20 epsilon units) if the bulk Zr concentration in the source is initially above 100 ppm and the melting is rapid (>10-4 yr-1). The decoupled release of zircon Hf and non-zircon Hf from a single crust-derived magma source can lead to significant Hf-isotope variations in a solidified granitic body. This work provides an alternative explanation for the Hf isotopic heterogeneity in magmatic zircons of granitic rocks, which is in contrast to the common interpretation by mixing with mantle-derived magmas.

  17. A Raman spectroscopic study of zircons on micro-scale and Its significance in explaining the origin of zircons

    E-print Network

    Xuezhao Bao; Huiming Li; Songnian Lu

    2007-08-15

    The magmatic and metamorphic zircons were investigated with Raman spectrum microprobe analysis. We found notable differences between these two kinds of zircons exhibited by the variation trend of Raman peak intensity from core to rim of a crystal. In magmatic zircons, the intensity and the ratio H/W of Raman spectrum peaks gradually decrease from core to rim of a crystal, which is produced by an increase in metamictization degree and suggests an increase in U and Th concentrations from core to rim. In metamorphic zircons, there are two kinds of crystals according to their Raman spectra: the first group of zircons exhibits a variation trend opposite to those of magmatic zircons, tending to increase in the Raman peak intensity and H/W value from core to rim of a crystal, which is produced by a decrease in metamictization degree and indicates a decrease of U and Th concentrations from core to rim of a crystal. The second group of zircons exhibits no change in Raman peak intensity and H/W value through a crystal. The data of infrared and Raman spectra of these crystals show that they are well crystallized and have no lattice destruction induced by metamictization, and are thought to crystallize in high temperature stages of metamorphism. During these stages, the U and Th ions have been removed by metamorphic fluids from the parent rocks of these zircons. The other difference between magmatic and metamorphic zircons is the background level of their Raman spectra, which is high and sloped in magmatic zircons, but low and horizontal in metamorphic zircons. The differences between magmatic and metamorphic zircons can be used to identify the genesis of zircons and understand the origin and evolution history of their parent rocks.

  18. The crystallization age of eucrite zircon.

    PubMed

    Srinivasan, G; Whitehouse, M J; Weber, I; Yamaguchi, A

    2007-07-20

    Eucrites are a group of meteorites that represent the first planetary igneous activity following metal-silicate differentiation on an early planetesimal, similar to Asteroid 4 Vesta, and, thus, help date geophysical processes occurring on such bodies in the early solar system. Using the short-lived radionuclide (182)Hf as a relative chronometer, we demonstrate that eucrite zircon crystallized quickly within 6.8 million years of metal-silicate differentiation. This implies that mantle differentiation on the eucrite parent body occurred during a period when internal heat from the decay of (26)Al and (60)Fe was still available. Later metamorphism of eucrites took place at least 8.9 million years after the zircons crystallized and was likely caused by heating from impacts, or by burial under hot material excavated by impacts, rather than from lava flows. Thus, the timing of eucrite formation and of mantle differentiation is constrained. PMID:17641194

  19. Trace-element composition of hydrothermal zircon and the alteration of Hadean zircon from the Jack Hills, Australia

    NASA Astrophysics Data System (ADS)

    Hoskin, Paul W. O.

    2005-02-01

    Hydrothermal zircon can be used to date fluid-infiltration events and water/rock interaction. At the Boggy Plain zoned pluton (BPZP), eastern Australia, hydrothermal zircon occurs with hydrothermal scheelite, molybdenite, thorite and rutile in incipiently altered aplite and monzogranite. The hydrothermal zircon is texturally distinct from magmatic zircon in the same rocks, occurring as murky-brown translucent 20-50 ?m-thick mantles on magmatic cores and less commonly as individual crystals. The hydrothermal mantles are internally textureless in back-scatter electron and cathodoluminescence images whereas magmatic zircon is oscillatory zoned. The age of the hydrothermal zircon is indistinguishable from magmatic zircon, indicating precipitation from a fluid evolved from the magma during the final stages of crystallization. Despite indistinguishable U-Pb isotopic compositions, the trace-element compositions of the hydrothermal and magmatic zircon are distinct. Hydrothermal zircon is enriched in all measured trace-elements relative to magmatic zircon in the same rock, including V, Ti, Nb, Hf, Sc, Mn, U, Y, Th and the rare-earth elements (REE). Chondrite-normalized REE abundances form two distinct pattern groupings: type-1 (magmatic) patterns increase steeply from La to Lu and have Ce and Eu anomalies—these are patterns typical for unaltered magmatic zircon in continental crust rock types; type-2 (hydrothermal) patterns generally have higher abundances of the REE, flatter light-REE patterns [(Sm/La) N = 1.5-4.4 vs. 22-110 for magmatic zircon] and smaller Ce anomalies (Ce/Ce* = 1.8-3.5 vs. 32-49 for magmatic zircon). Type-2 patterns have also been described for hydrothermally-altered zircon from the Gabel Hamradom granite, Egypt, and a granitic dyke from the Acasta Gneiss Complex, Canada. Hadean (˜4.5-4.0 Ga) zircon from the Jack Hills, Western Australia, have variable normalized REE patterns. In particular, the oldest piece of Earth—zircon crystal W74/2-36 (dated at 4.4 Ga)—contains both type-1 and type-2 patterns on a 50 ?m scale, a phenomenon not yet reported for unaltered magmatic zircon. In the context of documented magmatic and hydrothermal zircon compositions from constrained samples from the BPZP and the literature, the type-2 patterns in crystal W74/2-36 and other Jack Hills Hadean (JHH) zircon are interpreted as hydrothermally-altered magmatic compositions. An alteration scenario, constrained by isotope and trace-element data, as well as ?-decay event calculations, involving fluid/zircon cation and oxygen isotope exchange within partially metamict zones and minor dissolution/reprecipitation, may have occurred episodically for some JHH zircon and at ˜4.27 Ga for zircon W74/2-36. Type-2 compositions in JHH zircon are interpreted to represent localized exchange with a light-REE-bearing, high ? 18O (˜6-10‰ or higher) fluid. Thus, a complex explanation involving "permanent" liquid water oceans, large-scale water/rock interaction and plate tectonics in the very early Archean is not necessary as the zircon textures and compositions are simply explained by exchange between partially metamict zircon and a low volume ephemeral fluid.

  20. Rare-earth diffusion in zircon

    Microsoft Academic Search

    D. J. Cherniak; J. M. Hanchar; E. B. Watson

    1997-01-01

    Diffusion rates for three rare-earth elements (REEs: Sm, Dy, Yb) have been measured in synthetic and natural zircon. REE-phosphate powders were used as the source of diffusant, with Rutherford backscattering spectrometry (RBS) used to measure REE depth profiles.Over the temperature range 1150–1400°C, the following Arrhenius relations were obtained (diffusion coefficients in m2 s?1 ): log DYb = (7.40±1.15)+(?769±34 kJ mol?12.303

  1. Current status of Development of Mercury Dust Monitor for BepiColombo MMO

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.; Shibata, H.; Nogami, k.; Fujii, M.; Miyachi, T.; Ohashi, H.; Sasaki, S.; Iwai, T.; Hattori, M.; Kimura, H.; Hirai, T.; Takechi, S.; Yano, H.; Hasegawa, S.; Srama, R.; Grün, E.

    2012-09-01

    The Mercury dust monitor (MDM) will be the BepiColombo/Mercury magnetospheric orbiter (MMO) and be operated to clarify the dust environment around Mercury. The MDM employs lightweight and heat-resistant piezoelectric ceramic sensors made of lead zirconate titanate (PZT). This paper describes the current status of MDM development and ground calibration test using a dust accelerator facility.

  2. Resonance magnetoelectric effects in layered magnetostrictive-piezoelectric composites

    Microsoft Academic Search

    M. I. Bichurin; D. A. Filippov; V. M. Petrov; V. M. Laletsin; N. Paddubnaya; G. Srinivasan

    2003-01-01

    Magnetoelectric interactions in bilayers of magnetostrictive and piezoelectric phases are mediated by mechanical deformation. This work is concerned with the theory and companion data for magnetoelectric (ME) coupling at electromechanical resonance (EMR) in the layered samples. Estimated ME voltage coefficient versus frequency profiles for nickel, cobalt, or lithium ferrite and lead zirconate titanate (PZT) predict a giant ME effect at

  3. Micropatterning and crystallization of sol-gel-derived dielectric film by laser direct writing

    Microsoft Academic Search

    Akira Watanabe; Tomokazu Tanase; Kenji Miyajima; Yoshio Kobayashi; Mikio Konno

    2010-01-01

    Low temperature crystallization and the micropatterning of lead zirconate titanate (PZT) film were achieved by laser direct writing method using a sol-gel derived precursor film. After scanning of an Ar ion laser beam through an objective lens, the etching of the unirradiated area of the precursor film with an acidic solution gave micropatterns with a resolution of several mum. The

  4. Additive deposition and patterning of ferroelectric materials on non-planar surfaces by chemical-solution methods

    Microsoft Academic Search

    E. A. Mikalsen; D. A. Payne

    2000-01-01

    Recent developments and understanding for the deposition and patterning of ferroelectric thin layers are reported. Two patterning techniques are described for mediated chemical solution deposition by: (i) microcontact printing (?-CP), and (ii) micromolding in capillaries (MIMIC). These additive soft-lithographic methods are demonstrated for the patterning of sol-gel derived lead zirconate titanate (PZT) films on non-planar surfaces

  5. Locomotion response of airborne, ambulatory and aquatic insects to thermal stimulation using piezoceramic microheaters

    Microsoft Academic Search

    Karthik Visvanathan; Yogesh B Gianchandani

    2011-01-01

    This paper reports the locomotion response of airborne, ambulatory and aquatic insects to thermal stimulation. A finite element model has been developed to predict the variation of insect–stimulator interface temperature with input power. Piezothermal stimulators have been fabricated from lead zirconate titanate (PZT) using a batch mode micro ultrasonic machining process. Typical sizes range from 200 µm to 3.2 mm.

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

    Microsoft Academic Search

    I. Patel; E. Siores; T. Shah

    2010-01-01

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

  7. Synthesis of (Pb,La) (Zr,Ti)O3 films using a diol based sol–gel route

    Microsoft Academic Search

    R. Kurchania; S. J. Milne

    1998-01-01

    Morphotropic phase boundary compositions of lead zirconate titanate (PZT) modified with 2, 5 and 10 mol% lanthanum (PLZT) have been prepared using a diol based sol–gel route. Thin films of these PLZT compositions were fabricated on platinized silicon substrates by a spin coating technique. The effects of firing temperature and lanthanum modifications were investigated with regard to phase development, microstructure,

  8. Zircon megacrysts from kimberlite: oxygen isotope variability among mantle melts

    Microsoft Academic Search

    John W. Valley; Peter D. Kinny; Daniel J. Schulze; Michael J. Spicuzza

    1998-01-01

    The oxygen isotope ratios of Phanerozoic zircons from kimberlite pipes in the Kaapvaal Craton of southern Africa and the\\u000a Siberian Platform vary from 4.7 to 5.9‰ VSMOW. High precision, accurate analyses by laser reveal subtle pipe-to-pipe differences\\u000a not previously suspected. These zircons have distinctive chemical and physical characteristics identifying them as mantle-derived\\u000a megacrysts similar to zircons found associated with diamond,

  9. Rapid and Extensive Surface Changes Near Titan’s Equator: Evidence of April Showers

    NASA Astrophysics Data System (ADS)

    Turtle, E. P.; Perry, J. E.; Hayes, A. G.; Lorenz, R. D.; Barnes, J. W.; McEwen, A. S.; West, R. A.; Del Genio, A. D.; Barbara, J. M.; Lunine, J. I.; Schaller, E. L.; Ray, T. L.; Lopes, R. M. C.; Stofan, E. R.

    2011-03-01

    Although there is evidence that liquids have flowed on the surface at Titan’s equator in the past, to date, liquids have only been confirmed on the surface at polar latitudes, and the vast expanses of dunes that dominate Titan’s equatorial regions require a predominantly arid climate. We report the detection by Cassini’s Imaging Science Subsystem of a large low-latitude cloud system early in Titan’s northern spring and extensive surface changes (spanning more than 500,000 square kilometers) in the wake of this storm. The changes are most consistent with widespread methane rainfall reaching the surface, which suggests that the dry channels observed at Titan’s low latitudes are carved by seasonal precipitation.

  10. Optimization of PZT Diaphragm Pump for the Convective Gyroscope

    NASA Astrophysics Data System (ADS)

    Dau, Van Thanh; Dao, Dzung Viet; Dinh, Thien Xuan; Shiozawa, Tatsuo; Sugiyama, Susumu

    In this paper, we present the optimization of the PZT diaphragm pump for application in gas gyroscope. A circular flow inside the sealed case is simulated in detail by utilizing 3D compressible flow with the interaction of fluid-solid phase and the transient analysis is employed. The working principle and the effect of the jet-pump integrated inside the sensor are explained and validated by experiments using anemometry technique. The results verified that configuration of the pump is optimized and the peak velocity of the flow at the sensing element is 3.5m/sec after starting the pump 3.6ms. A novel structure of the sensing element of the gas gyroscope, consists of thermistor and heater, is also reported. The thermistor is heated by a separate heater, whose power is supplied independently form that of thermistor. This design allows low voltage on the thermistor, therefore the noise is reduced. Both heater and thermistor are optimized in order to reduce the thermal induced stress which occurred in the old thermistors at working temperatures. The thermal stress appeared in p-type silicon thermistors reduced the performance of sensor by 7.5%, which is calculated and experimentally confirmed.

  11. Microfabrication technique for thick structure of metals and PZT

    NASA Astrophysics Data System (ADS)

    Shimizu, Toru; Murakoshi, Yoichi; Wang, Zhanjie; Maeda, Ryutaro; Sano, Toshio

    1999-03-01

    Micro fabrication techniques for thick structure are developed. One method is a micro fabrication method using injection molding. And another method is the coating method using hydro gel. First method is almost same technique which is named MIM or CIM. In the process, the powder is mixed with the binder and mixture is injection molded. the molded parts are extracted the binder using supercritical carbon dioxide, and sintered. Employing this process, micro pattern which has aspect ratio more than 5 can be molded by metal powder and PZT. In this method, a micro pattern made by laser ablation is used as a die. As compared with other micro fabrication techniques, this method can utilize the molding die repeatedly. Consequently, the producing cost of micro parts can be decreased by this method on actual production process. Second method is a technique which uses the PVA hydrogel. The powder is mixed with water which contains the PVA from 3 to 15 percent. The mixed compound is sandwiched with PE films.It is froze and a gel sheet which has thickness from 40 to 100 micrometers is obtained. Using the sheet, the ceramic and metal are coated on the Silicon wafer, and thick structure is fabricated.

  12. Role of zircon in tracing crustal growth and recycling

    NASA Technical Reports Server (NTRS)

    Compston, W.; Williams, I. S.; Armstrong, R. A.; Claoue-Long, J. C.; Kinny, P. D.; Foster, J. J.; Kroener, A.; Pidgeon, R. T.; Myers, J. S.

    1988-01-01

    Single crystal ion probe ages of zircons is discussed, which allow much better time resolution compared to other geochronological methods, although the technique is not without problems. Rocks from two areas that contain composite zircon populations, including true magmatic zircons as well as a variety of xenocrystic types are described. It is often difficult to distinguish these; xenocrystic zircons, for example, cannot always be identified on the basis of morphology alone. Additional evidence is needed before making age interpretations. Evidence is also presented of zircon growth long after the original time of crystallization, in some cases apparently at temperatures less than 300 C. The spectacular discovery of 4.1 to 4.2 Ga detrital zircons in metaquartzites from the Mount Narryer area of Western Australia is described. Similar zircons with ages as old as 4276 Ma have been found in the nearby Jack Hills area. The source areas or parent lithologies of these zircons have not yet been determined, but the author expects that they may be unrecognized or buried antecedents of the K rich Narryer gneisses. U or Th concentrations of zircon cannot be used to discriminate between felsic and mafic source rocks.

  13. Assessment of errors in SIMS zircon U–Pb geochronology using a natural zircon standard and NIST SRM 610 glass

    Microsoft Academic Search

    Richard A Stern; Yuri Amelin

    2003-01-01

    Analytical errors calculated for individual spot 206Pb\\/238U measurements of zircon analyzed using high mass resolution secondary ion mass spectrometry (HR-SIMS, e.g., SHRIMP II) were assessed using natural zircon (z6266) and synthetic glass standards (NIST SRM 610). Evidence for U\\/Pb homogeneity of these materials includes new thermal ionization mass spectrometry (TIMS) U–Pb analyses of 22 fragments of z6266 zircon from two

  14. Organic sedimentary deposits in Titan’s dry lakebeds: Probable evaporite

    Microsoft Academic Search

    Jason W. Barnes; Jacob Bow; Jacob Schwartz; Robert H. Brown; Jason M. Soderblom; Alexander G. Hayes; Graham Vixie; Stéphane Le Mouélic; Sebastien Rodriguez; Christophe Sotin; Ralf Jaumann; Katrin Stephan; Laurence A. Soderblom; Roger N. Clark; Bonnie J. Buratti; Kevin H. Baines; Philip D. Nicholson

    2011-01-01

    We report the discovery of organic sedimentary deposits at the bottom of dry lakebeds near Titan’s north pole in observations from the Cassini Visual and Infrared Mapping Spectrometer (VIMS). We show evidence that the deposits are evaporitic, making Titan just the third known planetary body with evaporitic processes after Earth and Mars, and is the first that uses a solvent

  15. Titan-like reactors to simulate globally the chemistry in Titan's atmosphere

    E-print Network

    Kaiser, Ralf I.

    -RF plasma? #12;Conclusion 1 · In Titan's upper atmosphere, Cassini's observations have shown a complex ionicTitan-like reactors to simulate globally the chemistry in Titan's atmosphere Université de) Impossible with photolytic chamber (windows): only CH4 and HC chemistry. Note: synchrotron based experiments

  16. Annealing effects on cathodoluminescence of zircon

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Y.; Nishido, H.; Noumi, Y.

    2011-12-01

    U-Pb zircon dating (e. g., SHRIMP) is an important tool to interpret a history of the minerals at a micrometer-scale, where cathodoluminescence (CL) imaging allows us to recognize internal zones and domains with different chemical compositions and structural disorder at high spatial resolution. The CL of zircon is attributed by various types of emission centers, which are extrinsic ones such as REE impurities and intrinsic ones such as structural defects. Metamictization resulted from radiation damage to the lattice by alpha particles from the decay of U and Th mostly causes an effect on the CL features of zircon as a defect center. However, slightly radiation-damaged zircon, which is almost nondetectable by XRD, has not been characterized using CL method. In this study, annealing effects on CL of zircon has been investigated to clarify a recovery process of the damaged lattice at low radiation dose. A single crystal of zircon from Malawi was selected for CL measurements. It contains HfO2: 2.30 w.t %, U: 241 ppm and Th: 177 ppm. Two plate samples perpendicular to c and a axes were prepared for annealing experiments during 12 hours from room temperature to 1400 degree C. Color CL images were captured using a cold-cathode microscope (Luminoscope: Nuclide ELM-3R). CL spectral measurements were conducted using an SEM (JEOL: JSM-5410) combined with a grating monochromator (Oxford: Mono CL2) to measure CL spectra ranging from 300 to 800 nm in 1 nm steps with a temperature controlled stage. The dispersed CL was collected by a photoncounting method using a photomultiplier tube (Hamamatsu: R2228) and converted to digital data. All CL spectra were corrected for the total instrumental response. Spectral analysis reveals an anisotropy of the CL emission bands related to intrinsic defect center in blue region, radiation-induced defect center from 500 to 700 nm, and trivalent Dy impurity center at 480 and 580 nm, but their relative intensities are almost constant. CL on the surface perpendicular to c-axis, at which direction its intensity is maximum, was characterized in this study. Color CL imaging indicates yellow emission below 300 degree C, white to pale blue between 400 ~ 800 degree C and blue above 900 degree C. The broad band emission assigned to radiation-induced defect center in metamict state decreases in an increase of annealed temperature and disappeared above 700 degree C, whereas any change in XRD patterns was not detected. The blue CL emission caused by intrinsic defect center gradually increases in heating due to a recovery of its crystal field. Furthermore, the emission bands of trace amounts of trivalent Gd at 320 nm and Er at 400nm become to be appeared in response to a recrystallization by annealing. Therefore, CL analysis provides useful information on characteristics of the nature of metamict zircon rather than other conventional methods.

  17. Titan Oceanography from the Cassini

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph

    While the Cassini-Huygens mission was formulated against the speculative backdrop of a hydrocarbon ocean on Titan, the reality exposed by its measurements a quarter century later has proven more interesting. Instead of a global ocean, Titan has three modest seas, with dozens of small lakes, clustered around its north pole. The south is almost entirely bereft of surface liquids, the probable result of astronomically-forced climate cycles on Titan which are pumping ethane and methane vapor northwards across the equatorial deserts to accumulate in the long rainy season each boreal summer in the present epoch. Cassini’s RADAR instrument mapped the second-largest (~350km) sea, Ligiea Mare, while it was still in winter darkness, and has now covered the sprawling (~1000km) Kraken Mare, revealing shorelines indicating rising sea levels. The mapping allows the construction of numerical models of ocean circulation driven by winds and tides. Radar observations have placed tight limits (mm) on wave heights so far: near-infrared sunglint observations provide separate constraints on surface roughness. We will review latest observations and future plans: it is expected that winds will freshen as we move towards the culmination of the Cassini Solstice Mission in northern midsummer. The Ku-band (2.2cm) radar signals from Cassini penetrate a few meters into the possibly muddy dregs of Ontario Lacus in the south, yet remarkably allowed detection of a bottom echo at Ligeia Mare in a nadir-pointed altimetry observation in summer 2013. This not only allowed a depth estimation of ~170m, but also points to a very ‘clean’ composition, quite possibly rich in methane. This contrasts with near-infrared measurements at Ontario Lacus in the south, which show ethane and possibly an optically-muddy appearance. The stage is now set for detailed modeling of wind-driven and tidal circulations, mixing, stratification, sedimentation and shoreline processes on Titan. Beyond their insights into this environment, Cassini’s observations set the stage for future missions, which might include vehicles that float on, fly over, or even swim in, Titan’s exotic seas.

  18. Amino acidis derived from Titan tholins

    NASA Technical Reports Server (NTRS)

    Khare, Bishun N.; Sagan, Carl; Ogino, Hiroshi; Nagy, Bartholomew; Er, Cevat

    1986-01-01

    The production of amino acids by acid treatment of Titan tholin is experimentally investigated. The synthesis of Titan tholin and the derivatization of amino acids to N-trifluoroacetyl isopropyl esters are described. The gas chromatography/mass spectroscopy analysis of the Titan tholins reveals the presence of glycine, alpha and beta alainine, and aspartic acid, and the total yield of amino acids is about 0.01.

  19. Synthesis and characterization of new cystalline titanates

    E-print Network

    Nge, Renita

    1994-01-01

    -8 . . . . . . 53 . . . 54 . . . 55 11. Comparison of the XRD Patterns and Interlayer Distances of Small and Large Batches of the Titanates and Silico Titanates 58 12. The Composition of Swelling Preparations and the Interlayer Distances... surface areas, good chemical stability and high ion exchange capacities. They were classified into five types of titanates due to differences in method of synthesis, XRD pattern, surface area, and pore size distribution. One of these crystalline...

  20. Dissolution of PZT 52/48 in aqueous sulfuric acid environments

    NASA Astrophysics Data System (ADS)

    Calebrese, Steven

    With the recent interest for PZT use as a self-powered nanonsensor in extreme environments, such as an oil well, it is important to ensure the stability of the material under these conditions. Oil wells are known for being extremely caustic, with high temperature, low pH and high pressures. It has been shown that in the presence of sulfuric acid PZT is subject to chemical attack. This study attempts to identify the effects that pH and temperature have on the rate of the reaction. Sulfuric acid was used as a proxy for the H2S environment found in oil wells. Exposure of bulk PZT and thin film specimens to H2S was studied. PZT 52/48 thin films were fabricated via the sol gel process. PZT was exposed to both single drops of aqueous sulfuric acid and submerged in a bath of solution. During bath exposure potential on the substrate surface of thin film samples was recorded using a voltmeter vs. and Ag/AgCl reference electrode. Thin Film samples were exposed to a single drop of 0.1 N and 1 N aqueous sulfuric acid solutions at temperatures between 25° C and 92° C. It was optically observed that a white filmed appeared on the surface as a reaction product. At both concentrations, increases in temperature lead to an increase in reaction rate for droplet exposed samples. These reactions were found to follow Arrhenius behavior. The 1 N solution activation energy of film appearance was found to be 69100 J, and for 0.1 N solution was found to be 48300 J. It was expected that an increase in concentration would lead to an increase in reaction rate as well. However for single droplet exposure it was found that lower concentrations resulted in increased reaction rate. This may be due to the difference in interfacial energy between the solution and PZT surface as a result of the concentration of sulfuric acid. The potential on the substrate during bath exposure was between -0.22 V and 0.1 V. As a ferroelectric, PZT is expected to spontaneously polarize and variations in potential are expected. The value of -0.22 V corresponds to the potential of a normal hydrogen electrode, the conditions that would be found if the platinum layer were exposed, which could occur due to pinholes in the sample. The potential on the substrate and time of exposure were not found to correspond to dissolution depth using XPS depth profiling. A proposed reason is that attack was not found to be uniform across the surface, most likely as a result of high energy regions such as pinholes in the PZT film. Using XPS and XRD characterization techniques, PbSO4 was found to be one reaction product of both the PZT bulk sample exposed to a bath of solution, and thin film samples exposed to a single droplet of solution. Other reaction products were not able to be identified using the analysis techniques in this study, because the reaction products of zirconium and titanium are believed to take the form of ions in solution. While XPS confirmed their elemental presence in solution after evaporation, analysis of the solution itself was never conducted. Suggested future work and analytical techniques are also proposed to fully characterize the dissolution kinetics of PZT in aqueous sulfuric acid. These include the characterization of the interfacial energy between solution droplets and PZT surface, potentiostatic bath exposure of thin films in which the potential on the substrate is fixed, solution analysis via ICP-MS or other alternative, and the comparison of dissolution rate between bulk PZT and thin film PZT to determine the effect pinholes may have on the reaction. Various temperatures and acid concentrations are also proposed in order to fully characterize the Arrhenius behavior of reaction rate.

  1. Ferroelectric properties of PZT/BFO multilayer thin films prepared using the sol-gel method

    NASA Astrophysics Data System (ADS)

    Jo, Seo-Hyeon; Lee, Sung-Gap; Lee, Young-Hie

    2012-01-01

    In this study, Pb(Zr0.52Ti0.48)O3/BiFeO3 [PZT/BFO] multilayer thin films were fabricated using the spin-coating method on a Pt(200 nm)/Ti(10 nm)/SiO2(100 nm)/p-Si(100) substrate alternately using BFO and PZT metal alkoxide solutions. The coating-and-heating procedure was repeated several times to form the multilayer thin films. All PZT/BFO multilayer thin films show a void-free, uniform grain structure without the presence of rosette structures. The relative dielectric constant and dielectric loss of the six-coated PZT/BFO [PZT/BFO-6] thin film were approximately 405 and 0.03%, respectively. As the number of coatings increased, the remanent polarization and coercive field increased. The values for the BFO-6 multilayer thin film were 41.3 C/cm2 and 15.1 MV/cm, respectively. The leakage current density of the BFO-6 multilayer thin film at 5 V was 2.52 × 10-7 A/cm2.

  2. PMN-PT–PZT composite films for high frequency ultrasonic transducer applications

    PubMed Central

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Zheng, Fan; Chen, Rumin; Huang, Yuhong; Zhou, Qifa; Shung, K. Kirk

    2013-01-01

    We have successfully fabricated x(0.65PMN-0.35PT)–(1 ? x)PZT (xPMN-PT–(1 ? x)PZT), where x is 0.1, 0.3, 0.5, 0.7 and 0.9, thick films with a thickness of approximately 9 µm on platinized silicon substrate by employing a composite sol–gel technique. X-ray diffraction analysis and scanning electron microscopy revealed that these films are dense and creak-free with well-crystallized perovskite phase in the whole composition range. The dielectric constant can be controllably adjusted by using different compositions. Higher PZT content of xPMN-PT–(1 ? x)PZT films show better ferroelectric properties. A representative 0.9PMN-PT–0.1PZT thick film transducer is built. It has 200 MHz center frequency with a ?6 dB bandwidth of 38% (76 MHz). The measured two-way insertion loss is 65 dB. PMID:23750072

  3. Ferroelectric properties of PZT/BFO multilayer thin films prepared using the sol-gel method

    PubMed Central

    2012-01-01

    In this study, Pb(Zr0.52Ti0.48)O3/BiFeO3 [PZT/BFO] multilayer thin films were fabricated using the spin-coating method on a Pt(200 nm)/Ti(10 nm)/SiO2(100 nm)/p-Si(100) substrate alternately using BFO and PZT metal alkoxide solutions. The coating-and-heating procedure was repeated several times to form the multilayer thin films. All PZT/BFO multilayer thin films show a void-free, uniform grain structure without the presence of rosette structures. The relative dielectric constant and dielectric loss of the six-coated PZT/BFO [PZT/BFO-6] thin film were approximately 405 and 0.03%, respectively. As the number of coatings increased, the remanent polarization and coercive field increased. The values for the BFO-6 multilayer thin film were 41.3 C/cm2 and 15.1 MV/cm, respectively. The leakage current density of the BFO-6 multilayer thin film at 5 V was 2.52 × 10-7 A/cm2. PMID:22221519

  4. Titan In Situ Exploration Concepts at JPL

    NASA Technical Reports Server (NTRS)

    Elliott, John O.; Hall, Jeffery L.; Jones, Jack; Reh, Kim

    2008-01-01

    This slide presentation reviews concepts for exploring Titan via balloon vehicles. The presentation includes information about the baseline options, the deployment scenario, and the balloon technology development.

  5. The Global Energy Balance of Titan

    NASA Technical Reports Server (NTRS)

    Li, Liming; Nixon, Conor A.; Achterberg, Richard K.; Smith, Mark A.; Gorius, Nicolas J. P.; Jiang, Xun; Conrath, Barney J.; Gierasch, Peter J.; Simon-Miller, Amy A.; Flasar, F. Michael; Baines, Kevin H.; Ingersoll, Andrew P.; West, Robert A.; Vasavada, Ashwin R.; Ewald, Shawn P.

    2011-01-01

    We report the first measurement of the global emitted power of Titan. Longterm (2004-2010) observations conducted by the Composite Infrared Spectrometer (CIRS) onboard Cassini reveal that the total emitted power by Titan is (2.84 plus or minus 0.01) x 10(exp 8) watts. Together with previous measurements of the global absorbed solar power of Titan, the CIRS measurements indicate that the global energy budget of Titan is in equilibrium within measurement error. The uncertainty in the absorbed solar energy places an upper limit on the energy imbalance of 5.3%.

  6. The magnetic memory of Titan's ionized atmosphere.

    PubMed

    Bertucci, C; Achilleos, N; Dougherty, M K; Modolo, R; Coates, A J; Szego, K; Masters, A; Ma, Y; Neubauer, F M; Garnier, P; Wahlund, J-E; Young, D T

    2008-09-12

    After 3 years and 31 close flybys of Titan by the Cassini Orbiter, Titan was finally observed in the shocked solar wind, outside of Saturn's magnetosphere. These observations revealed that Titan's flow-induced magnetosphere was populated by "fossil" fields originating from Saturn, to which the satellite was exposed before its excursion through the magnetopause. In addition, strong magnetic shear observed at the edge of Titan's induced magnetosphere suggests that reconnection may have been involved in the replacement of the fossil fields by the interplanetary magnetic field. PMID:18787164

  7. Pluto's implications for a Snowball Titan

    NASA Astrophysics Data System (ADS)

    Wong, Michael L.; Yung, Yuk L.; Randall Gladstone, G.

    2015-01-01

    The current Cassini-Huygens Mission to the Saturn system provides compelling evidence that the present state of Titan's dense atmosphere is unsustainable over the age of the Solar System. Instead, for most of its existence, Titan's atmosphere might have been in a Snowball state, characterized by a colder surface and a smaller amount of atmospheric CH4, similar to that of Pluto or Triton. We run a 1-D chemical transport model and show that the rates of organic synthesis on a Snowball Titan are significantly slower than those on present-day Titan. The primary method of methane destruction-photosensitized dissociation in the stratosphere-is greatly dampened on Snowball Titan. The downward flux of higher-order molecules through the troposphere is dominated not by hydrocarbons such as ethane, as is the case on Titan today, but by nitriles. This result presents a testable observation that could confirm the Snowball Titan hypothesis. Because Pluto's atmosphere is similar to Titan's in composition, it serves as a basis for comparison. Future observations of Pluto by the New Horizons Mission will inform photochemical models of Pluto's atmosphere and can help us understand the photochemical nature of paleo-Titan's atmosphere.

  8. Hydrodynamic fractionation of zircon age populations in fluvial transport

    NASA Astrophysics Data System (ADS)

    Lawrence, R. L.; Cox, R.; Mapes, R. W.; Coleman, D. S.

    2008-12-01

    Because it is generally assumed that zircon age populations are not significantly fractionated during transport, detrital zircon provenance studies usually characterize locations or units with a single sample. But zircons vary in size by an order of magnitude, ranging from 10s of ?m to a few hundred ?m in length (i.e. coarse silt to medium sand). Hydrodynamic fractionation of grain sizes is therefore likely; and if different age populations have different characteristic sizes, then the population proportions in a given sample are likely to be influenced by local depositional mechanics. Thus, a single sample may not fully characterize zircon populations for a given location or stratigraphic interval. We examined size and age of zircons from twelve locations along the Amazon River, and compared the data with grain size distributions of the host sands. We found that old zircons in the Amazon tend to be smaller (significant at > 2? level), and that there is a significant relationship between median grain size of concordant zircons in a sample and median age of the sample. Furthermore, sands with a larger coarse fraction tend to have larger zircons. The inference is that zircons are fractionated by size; and if size and age are related (as in this example), age populations are likely to be affected. To test whether zircon age populations are affected by local hydrodynamics, we analyzed five sand samples from different sub-environments of a single Amazon River dune (28 m x 1 m). We sampled the upstream and downstream troughs, the stoss, and the upper and lower lee slope. From each sample we obtained 51-71 concordant (100 ±10%) zircon ages (using LA-ICPMS). Using probability density diagrams and mixture modeling to define ages and proportions of population components, we found significant differences (2? level) between samples. In the most extreme case, one sample had an age population not seen in any other, and lacked a population that was present in all other samples. As all samples came from the same site, with hydrodynamic microenvironment the only variable, our results suggest that there may be significant sedimentological effects on zircon age populations. Zircon age populations are not independent of grain size, and hydrodynamic fractionation can affect the number and relative proportions of age populations in a given sample. Although further analyses are necessary to confirm our interpretations, these initial results suggest that single samples may not reliably characterise zircon populations. Comparative provenance analysis may require samples from multiple micro- environments to produce a representative picture of zircon age distributions.

  9. Fire & Ice: Hindenburg and Titanic

    NSDL National Science Digital Library

    2012-03-22

    The National Postal Museum recently created a rather nice in situ exhibit with this great online component to bring together materials on two marvels (and disasters) of modern transportation: the Titanic and the Hindenburg. The exhibit brought together unique items such as postcards and programs in one place so that visitors could learn about these rather fantastic forms of conveyance. The exhibit takes its name from the poem "Fire and Ice" by Robert Frost in which he mused "Some say the world will end in fire, some say in ice." The sections of the exhibit include Life Onboard, Mail Ships, and Technologically Advanced. Visitors can scan through each section to view a number of items, such as a fabric purse from the Hindenburg and a photo of the elaborate squash court on the Titanic. Not surprisingly, the Rarities area contains some postal history treasures, including an envelope sent from the Hindenburg which was discovered in the wreckage.

  10. The organic aerosols of Titan

    NASA Technical Reports Server (NTRS)

    Khare, B. N.; Sagan, C.; Thompson, W. R.; Arakawa, E. T.; Suits, F.; Callcott, T. A.; Williams, M. W.; Shrader, S.; Ogino, H.; Willingham, T. O.

    1984-01-01

    The optical properties and chemical composition of thiolin, an organic solid synthesized by high-energy-electron irradiation in a plasma discharge (Sagan et al., 1984) to simulate the high-altitude aerosols of Titan, are investigated experimentally using monochromators, ellipsometers, and spectrometers (on thin films deposited by continuous dc discharge) and sequential and nonsequential pyrolytic gas chromatography/mass spectrometry (of the volatile component), respectively. The results are presented in tables and graphs and characterized. The real and imaginary elements of the complex refractive index in the visible are estimated as 1.65 and 0.004-0.08, respectively, in agreement with observations of Titan, and the IR absorption features include the nitrile band at 4.6 microns. The molecules identified in the volatile part of thiolin include complex species considered important in theoretical models of the origin of life on earth.

  11. Titan's geoid and hydrology: implications for Titan's geological evolution

    NASA Astrophysics Data System (ADS)

    Sotin, Christophe; Seignovert, Benoit; Lawrence, Kenneth; MacKenzie, Shannon; Barnes, Jason; Brown, Robert

    2014-05-01

    A 1x1 degree altitude map of Titan is constructed from the degree 4 gravity potential [1] and Titan's shape [2] determined by the Radio Science measurements and RADAR observations of the Cassini mission. The amplitude of the latitudinal altitude variations is equal to 300 m compared to 600 m for the amplitude of the latitudinal shape variations. The two polar caps form marked depressions with an abrupt change in topography at exactly 60 degrees at both caps. Three models are envisaged to explain the low altitude of the polar caps: (i) thinner ice crust due to higher heat flux at the poles, (ii) fossil shape acquired if Titan had higher spin rate in the past, and (iii) subsidence of the crust following the formation of a denser layer of clathrates as ethane rain reacts with the H2O ice crust [3]. The later model is favored because of the strong correlation between the location of the cloud system during the winter season and the latitude of the abrupt change in altitude. Low altitude polar caps would be the place where liquids would run to and eventually form large seas. Indeed, the large seas of Titan are found at the deepest locations at the North Pole. However, the lakes and terrains considered to be evaporite candidates due to their spectral characteristics in the infrared [4,5] seem to be perched. Lakes may have been filled during Titan's winter and then slowly evaporated leaving material on the surface. Interestingly, the largest evaporite deposits are located at the equator in a deep depression 150 m below the altitude of the northern seas. This observation seems to rule out the presence of a global subsurface hydrocarbon reservoir unless the evaporation rate at the equator is faster than the transport of fluids from the North Pole to the equator. This work has been performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. [1] Iess L. et al. (2012) Science, doi 10.1126/science.1219631. [2] Lorenz R.D. (2013) Icarus, 225, 367-377. [3] Choukroun M. and C. Sotin (2012) Geophys. Res. Lett., 39, L0420. [4] Barnes J.W. et al. (2011) Icarus, 216, 136-140. [5] MacKenzie S.M. et al. (2014) submitted to JGR.

  12. Cassini Imaging Results at Titan

    NASA Technical Reports Server (NTRS)

    McEwen, A.; Turtle, E.; Perry J.; Fussner, S.; Porco, C.; West, R.; Johnson, T.; Collins, G.; DelGenio, T.; Barbara, J.

    2005-01-01

    The Cassini Imaging Science Subsystem (ISS) images show striking albedo markings on the surface of Titan. In equatorial regions the albedo patterns have high contrast and exhibit prominent lineaments and linear/angular boundaries suggestive of tectonic influences or fracturing of brittle surficial materials. There are intriguing dark curving lines near the south pole. Here we present several working hypotheses to explain these patterns. We also briefly summarize atmospheric science results.

  13. Titan’s Rotation Reveals an Internal Ocean and Changing Zonal Winds

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph D.; Stiles, Bryan W.; Kirk, Randolph L.; Allison, Michael D.; Persi del Marmo, Paolo; Iess, Luciano; Lunine, Jonathan I.; Ostro, Steven J.; Hensley, Scott

    2008-03-01

    Cassini radar observations of Saturn’s moon Titan over several years show that its rotational period is changing and is different from its orbital period. The present-day rotation period difference from synchronous spin leads to a shift of ~0.36° per year in apparent longitude and is consistent with seasonal exchange of angular momentum between the surface and Titan’s dense superrotating atmosphere, but only if Titan’s crust is decoupled from the core by an internal water ocean like that on Europa.

  14. Octahedral tilting, monoclinic phase and the phase diagram of PZT.

    PubMed

    Cordero, F; Trequattrini, F; Craciun, F; Galassi, C

    2011-10-19

    Anelastic and dielectric spectroscopy measurements on PbZr(1-x)Ti(x)O(3) (PZT) close to the morphotropic (MPB) and antiferroelectric boundaries provide new insight into some controversial aspects of its phase diagram. No evidence is found of a border separating monoclinic (M) from rhombohedral (R) phases, in agreement with recent structural studies supporting a coexistence of the two phases over a broad composition range x<0.5, with the fraction of M increasing toward the MPB. It is also discussed why the observed maximum of elastic compliance appears to be due to a rotational instability of the polarization linearly coupled to shear strain. Therefore it cannot be explained by extrinsic softening from finely twinned R phase alone, but indicates the presence also of M phase, not necessarily homogeneous.A new diffuse transition is found within the ferroelectric phase near x ~ 0.1, at a temperature T(IT) higher than the well established boundary T(T) to the phase with tilted octahedra. It is proposed that around T(IT) the octahedra start rotating in a disordered manner and finally become ordered below T(T). In this interpretation, the onset temperature for octahedral tilting monotonically increases up to the antiferroelectric transition of PbZrO(3), and the depression of T(T)(x) below x=0.18 would be a consequence of the partial relief of the mismatch between the average cation radii with the initial stage of tilting below T(IT). PMID:21946859

  15. Safe prescribing: a titanic challenge

    PubMed Central

    Routledge, Philip A

    2012-01-01

    The challenge to achieve safe prescribing merits the adjective ‘titanic’. The organisational and human errors leading to poor prescribing (e.g. underprescribing, overprescribing, misprescribing or medication errors) have parallels in the organisational and human errors that led to the loss of the Titanic 100 years ago this year. Prescribing can be adversely affected by communication failures, critical conditions, complacency, corner cutting, callowness and a lack of courage of conviction, all of which were also factors leading to the Titanic tragedy. These issues need to be addressed by a commitment to excellence, the final component of the ‘Seven C's’. Optimal prescribing is dependent upon close communication and collaborative working between highly trained health professionals, whose role is to ensure maximum clinical effectiveness, whilst also protecting their patients from avoidable harm. Since humans are prone to error, and the environments in which they work are imperfect, it is not surprising that medication errors are common, occurring more often during the prescribing stage than during dispensing or administration. A commitment to excellence in prescribing includes a continued focus on lifelong learning (including interprofessional learning) in pharmacology and therapeutics. This should be accompanied by improvements in the clinical working environment of prescribers, and the encouragement of a strong safety culture (including reporting of adverse incidents as well as suspected adverse drug reactions whenever appropriate). Finally, members of the clinical team must be prepared to challenge each other, when necessary, to ensure that prescribing combines the highest likelihood of benefit with the lowest potential for harm. PMID:22738396

  16. Safe prescribing: a titanic challenge.

    PubMed

    Routledge, Philip A

    2012-10-01

    The challenge to achieve safe prescribing merits the adjective 'titanic'. The organisational and human errors leading to poor prescribing (e.g. underprescribing, overprescribing, misprescribing or medication errors) have parallels in the organisational and human errors that led to the loss of the Titanic 100 years ago this year. Prescribing can be adversely affected by communication failures, critical conditions, complacency, corner cutting, callowness and a lack of courage of conviction, all of which were also factors leading to the Titanic tragedy. These issues need to be addressed by a commitment to excellence, the final component of the 'Seven C's'. Optimal prescribing is dependent upon close communication and collaborative working between highly trained health professionals, whose role is to ensure maximum clinical effectiveness, whilst also protecting their patients from avoidable harm. Since humans are prone to error, and the environments in which they work are imperfect, it is not surprising that medication errors are common, occurring more often during the prescribing stage than during dispensing or administration. A commitment to excellence in prescribing includes a continued focus on lifelong learning (including interprofessional learning) in pharmacology and therapeutics. This should be accompanied by improvements in the clinical working environment of prescribers, and the encouragement of a strong safety culture (including reporting of adverse incidents as well as suspected adverse drug reactions whenever appropriate). Finally, members of the clinical team must be prepared to challenge each other, when necessary, to ensure that prescribing combines the highest likelihood of benefit with the lowest potential for harm. PMID:22738396

  17. FAST TRACK COMMUNICATION: The large magnetoelectric effect in Ni-lead zirconium titanate-Ni trilayers derived by electroless deposition

    NASA Astrophysics Data System (ADS)

    Bi, K.; Wang, Y. G.; Wu, W.; Pan, D. A.

    2010-04-01

    Magnetoelectric (ME) Ni-lead zirconium titanate-Ni trilayers with neither electrodes nor bonding layers have been derived by electroless deposition. The structure and magnetic properties of the electroless deposited Ni layers with different pH values are characterized by x-ray diffraction and vibrating sample magnetometer. The influence of the bias magnetic field and the magnetic field frequency (f) on ME coupling is discussed. It is seen that ?E,31 depends strongly on Hdc and f. The value of the ME coefficient increases as the thickness of the Ni layer and the pH of the bath increase. A maximum of the ME voltage coefficient ?E,31 = 5.77 V cm-1 Oe-1 at resonance frequency with a deposited Ni layer thickness tNi = 302 µm is obtained. The large ME coefficient makes these Ni-PZT-Ni trilayers suitable for applications in sensors, actuators and transducers.

  18. Temperature Field Analysis for PZT Pyroelectric Cells for Thermal Energy Harvesting

    PubMed Central

    Hsiao, Chun-Ching; Ciou, Jing-Chih; Siao, An-Shen; Lee, Chi-Yuan

    2011-01-01

    This paper proposes the idea of etching PZT to improve the temperature variation rate of a thicker PZT sheet in order to enhance the energy conversion efficiency when used as pyroelectric cells. A partially covered electrode was proven to display a higher output response than a fully covered electrode did. A mesh top electrode monitored the temperature variation rate and the electrode area. The mesh electrode width affected the distribution of the temperature variation rate in a thinner pyroelectric material. However, a pyroelectric cell with a thicker pyroelectric material was beneficial in generating electricity pyroelectrically. The PZT sheet was further etched to produce deeper cavities and a smaller electrode width to induce lateral temperature gradients on the sidewalls of cavities under homogeneous heat irradiation, enhancing the temperature variation rate. PMID:22346652

  19. PAC investigation on the Zr-rich region of the PZT phase diagram

    NASA Astrophysics Data System (ADS)

    Alonso, R. E.; Ayala, A. P.; López García, A. R.; Eiras, J. A.

    2007-02-01

    Previous studies using perturbed angular correlation (PAC) spectroscopy in the PbZr 1-xTi xO 3 (PZT) family of compounds show that whereas PbZrO 3 is characterized by a single probes site with a very well-defined hyperfine interaction, in PZT with x?0.1 the probes occupy two distributed sites. In this work, we investigate the Zr-rich region of the PZT phase diagram from x=0.02 up to x=0.08 using PAC in order to correlate the hyperfine parameters with the antiferroelectric-ferroelectric phase transition reported to occur at x=0.05. Two static electric quadrupole interactions, one of them fairly distributed, were detected over the whole Ti concentration range, and an abrupt change in the hyperfine parameters for 0.02< x<0.04 is observed. The behaviour of these parameters and the existence of two probe sites is discussed.

  20. A flexible ultrasound transducer array with micro-machined bulk PZT.

    PubMed

    Wang, Zhe; Xue, Qing-Tang; Chen, Yuan-Quan; Shu, Yi; Tian, He; Yang, Yi; Xie, Dan; Luo, Jian-Wen; Ren, Tian-Ling

    2015-01-01

    This paper proposes a novel flexible piezoelectric micro-machined ultrasound transducer, which is based on PZT and a polyimide substrate. The transducer is made on the polyimide substrate and packaged with medical polydimethylsiloxane. Instead of etching the PZT ceramic, this paper proposes a method of putting diced PZT blocks into holes on the polyimide which are pre-etched. The device works in d31 mode and the electromechanical coupling factor is 22.25%. Its flexibility, good conformal contacting with skin surfaces and proper resonant frequency make the device suitable for heart imaging. The flexible packaging ultrasound transducer also has a good waterproof performance after hundreds of ultrasonic electric tests in water. It is a promising ultrasound transducer and will be an effective supplementary ultrasound imaging method in the practical applications. PMID:25625905