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1

R-curves of lead zirconate titanate (PZT)  

Microsoft Academic Search

R-curves were measured for ferroelectric ceramic lead zirconate titanate (PZT) using surface cracks in flexure (SCF) in a single composition of unpoled, ferroelastic PZT. The effects of several parameters on the R-curves were experimentally determined. These included grain size, indentation load, polishing away the residual stress zone associated with the Knoop indentation, and thermal depolarization after indentation. The larger grain

Thomas Karastamatis; Doru C. Lupascu; Jürgen Rödel; Christopher S. Lynch

2003-01-01

2

Hydrothermal synthesis of acicular lead zirconate titanate (PZT)  

Microsoft Academic Search

The hydrothermal synthesis of lead zirconate titanate (PZT) powder with acicular morphology using organic mineralizer, tetramethylammonium hydroxide pentahydrate (TMAH), has been investigated. The TMAH concentration and reaction time have a pronounced effect on the phase composition and morphology of the resultant powders. At 150°C phase pure PZT was obtained after 24h in 0.5m TMAH solution, and after 12h in 1m

Seung-Beom Cho; Magdalena Oledzka; Richard E Riman

2001-01-01

3

Effect of grain size on the R-curve behavior of lead zirconate titanate (PZT)  

Microsoft Academic Search

R-curves were measured for ferroelectric ceramic lead zirconate titanate (PZT) with two different grain sizes using the surface crack in flexure technique. Larger grain size resulted in a higher plateau value of the R-curve. This was consistent with the larger amount of ferroelastic switching observed from the stress\\/strain curve.

Thomas Karastamatis; Doru C. Lupascu; Sergio Lucato; Christopher S. Lynch

2001-01-01

4

Active micromixer for microfluidic systems using lead-zirconate-titanate (PZT)-generated ultrasonic vibration.  

PubMed

A micromixer using direct ultrasonic vibration is first reported in this paper. The ultrasonic vibration was induced by a bulk lead-zirconate-titanate (PZT; 5 x 4 x 0.2 mm), which was excited by a 48 kHz square wave at 150 V (peak-to-peak). Liquids were mixed in a chamber (6 x 6 x 0.06 mm) with an oscillating diaphragm driven by the PZT. The oscillating diaphragm was in the size of 6 x 6 x 0.15 mm. Ethanol and water were used to test the mixing effectiveness. The laminar flows of ethanol (115 microL/min) and water (100 microL/min) were mixed effectively when the PZT was excited. The entire process was recorded using a video camera. PMID:10634477

Yang, Z; Goto, H; Matsumoto, M; Maeda, R

2000-01-01

5

Lead zirconate titanate (PZT)-based thin film capacitors for embedded passive applications  

NASA Astrophysics Data System (ADS)

Investigations on the key processing parameters and properties relationship for lead zirconate titanate (PZT, 52/48) based thin film capacitors for embedded passive capacitor application were performed using electroless Ni coated Cu foils as substrates. Undoped and Ca-doped PZT (52/48) thin film capacitors were prepared on electroless Ni coated Cu foil by chemical solution deposition. For PZT (52/48) thin film capacitors on electroless Ni coated Cu foil, voltage independent (zero tunability) capacitance behavior was observed. Dielectric constant reduced to more than half of the identical capacitor processed on Pt/SiO2/Si. Dielectric properties of the capacitors were mostly dependent on the crystallization temperature. Capacitance densities of almost 350 nF/cm2 and 0.02˜0.03 of loss tangent were routinely measured for capacitors crystallized at 575˜600°C. Leakage current showed dependence on film thickness and crystallization temperature. From a two-capacitor model, the existence of a low permittivity interface layer (permittivity ˜30) was suggested. For Ca-doped PZT (52/48) thin film capacitors prepared on Pt, typical ferroelectric and dielectric properties were measured up to 5 mol% Ca doping. When Ca-doped PZT (52/48) thin film capacitors were prepared on electroless Ni coated Cu foil, phase stability was influenced by Ca doping and phosphorous content. Dielectric properties showed dependence on the crystallization temperature and phosphorous content. Capacitance density of ˜400 nF/cm2 was achieved, which is an improvement by more than 30% compared to undoped composition. Ca doping also reduced the temperature coefficient of capacitance (TCC) less than 10%, all of them were consistent in satisfying the requirements of embedded passive capacitor. Leakage current density was not affected significantly by doping. To tailor the dielectric and reliability properties, ZrO2 was selected as buffer layer between PZT and electroless Ni. Only RF magnetron sputtering process could yield stable ZrO2 layers on electroless Ni coated Cu foil. Other processes resulted in secondary phase formation, which supports the reaction between PZT capacitor and electroless Ni might be dominated by phosphorous component. (Abstract shortened by UMI.)

Kim, Taeyun

6

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

7

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

NASA Astrophysics Data System (ADS)

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.

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

2011-03-01

8

Dielectric properties of rare earth (Sm and La) substituted lead zirconate titanate (PZT) ceramics  

NASA Astrophysics Data System (ADS)

In the present paper, we are reporting the studies on dielectric properties of Lanthanum (La) and Samarium (Sm) substituted Lead Zirconate Titanate with compositional formula Pb(1.02-x)SmxZr0.55Ti0.45O3 and Pb(1.02-x)LaxZr0.55Ti0.45O3 with x = 0.00, 0.01, 0.02, 0.03. The materials were synthesized by solid state reaction route. XRD analysis shows that all the samples be in single phase with tetragonal structure. Dielectric properties were studied as a function of temperature.

Dipti; Singh, Sangeeta; Juneja, J. K.; Raina, K. K.; Prakash, Chandra

2013-06-01

9

Lead zirconate titanate ceramics  

SciTech Connect

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

Walker, B.E. Jr.

1986-12-02

10

Reactive ion etching of lead zirconate titanate (PZT) thin film capacitors  

SciTech Connect

One of the key processing concerns in the integration of PbZr[sub x]Ti[sub 1[minus]x]O[sub 3](PZT) thin film capacitors into the existing VLSI for ferroelectric or dynamic random access memory applications is the patterning of these films and the electrodes. In this work, the authors have identified a suitable etch gas (CCl[sub 2]F[sub 2]) for dry etching of PZT thin films on RuO[sub 2] electrodes. The etch rate and anisotropy have been studied as a function of etching conditions. The trends in the effect on the etch rate of the gas pressure, RF power and O[sub 2] additions to the etch gas have been determined and an etching mechanism has been proposed. It was found that ion bombardment effects are primarily responsible for the etching of both PZT and RuO[sub 2] thin films. Etch rates of the order of 20--30 nm/min were obtained for PZT thin films under low gas pressure and high RF power conditions. The etch residues and the relative etch rates of the components of the PZT solid solution were determined using XPS. The results show that the etching of PbO is the limiting factor in the etch process.

Vijay, D.P.; Desu, S.B.; Pan, W. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Materials Science and Engineering)

1993-09-01

11

Design, fabrication, test, and evaluation of RF MEMS series switches using lead zirconate titanate (PZT) thin film actuators  

NASA Astrophysics Data System (ADS)

The aim of this thesis was to design and prototype a robust, low voltage RF MEMS switch for use in military phased arrays. The frequencies of interest for this work include very low frequencies down to DC operation with the upper limit extending to at least 40 GHz. This broad frequency requirement requires a robust high frequency design and simulation using microwave transmission lines. With the aid of researchers at the US Army Research Laboratory, co-planar waveguide (CPW) transmission lines were chosen and designed to provide a low loss, 50 ohm impedance transmission line for the switch. CPW designs allow for both series and shunt switch configuration with this work focusing on a series switch. Furthermore, a series switch an ohmic contact was chosen as opposed to capacitive contacts. Piezoelectric actuation is chosen for the switch to enable operating voltages less than 10 volts while still maintaining a restoring force to prevent stiction. To meet these demands, lead zirconate titanate (PZT) thin films have been chosen for the piezoelectric actuator. Mechanical modeling of cantilevers comprised of an elastic layer and a Pt-PZT-Pt actuator were used to demonstrate feasibility of closing large gaps between switch contacts. Placement of the actuator to minimize perturbations to the RF transmission line is critical for broadband performance. Using fabrication design rules, electro-mechanical modeling, and high frequency design, the actuators were designed to fit with the RF gap between the RF conductor and ground planes of the CPW transmission line. Optimal performance was obtained with the actuators mechanically isolated from a majority of the RF transmission except for a small section that provides the contact pad to enable switch closure. The resulting switch is the first demonstrated first surface micromachined RF MEMS switch operating from DC to 65 GHz. This switch has a median actuation voltage below 5 volts with operation as low as 2 volts. Isolation in the off state is better than -20 dB across the frequency band with values better than -60 dB observed for frequency below 1 GHz. The insertion loss in the on state is less than 1 dB below 40 GHz and remains below 2 dB up to 65 GHz. Switching time was demonstrated at 40 mus and was limited by bouncing between the contacts, with initial contact observed at less than 10 mus. The cycle reliability of this switch has been tested with high contact resistance failures observed in the low 106 cycles range. The reliability appears to be limited by organic contamination between the contacting surfaces, possibly the result of resist residue and/or the development of a frictional polymer on the platinum coated contact surface. With one application of this RF MEMS switch targeted for military phased arrays, temperature sensitivity is an extremely important characteristic. The PZT SW5.1 design exhibited excellent off state performance with no change in the isolation characteristics from -25°C to 100°C. However, in the on state, the actuation voltage is required to increase to 20 volts to ensure operation at 100°C. The temperature sensitivity was improved by redesigning the RF contact pad to enable co-linear contact between the RF input and output sides of the transmission. This redesign, PZT SW5.2, successfully enables operation of the PZT RF MEMS switch from -25°C to 100°C with an actuation voltage less than 10 volts. The isolation of the newer design remains similar to the earlier design with values better than -20 dB up through 50 GHz. The insertion loss of this design exhibited a slight improvement compared to the earlier design with values less than 0.3 dB below 40 GHz and rising to 0.5 dB up through 50 GHz. (Abstract shortened by UMI.)

Polcawich, Ronald G.

12

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

NASA Astrophysics Data System (ADS)

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

Berfield, Thomas A.

13

Using the methods of radiospectroscopy (EPR, NMR) to study the nature of the defect structure of solid solutions based on lead zirconate titanate (PZT).  

PubMed

Abstract¿The nature of intrinsic and impurity point defects in lead zirconate titanate (PZT) ceramics has been explored. Using electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS) methods, several impurity sites have been identified in the materials, including the Fe(3+)-oxygen vacancy (VO) complex and Pb ions. Both of these centers are incorporated into the PZT lattice. The Fe(3+)%#x2013;V paramagnetic complex serves as a sensitive probe of the local crystal field in the ceramic; the symmetry of this defect roughly correlates with PZT phase diagram as the composition is varied from PbTiO3 to PbZrO3. NMR spectra (207)Pb in PbTiO3, PbZrO3, and PZT with iron content from 0 to 0.4 wt% showed that increasing the iron concentration leads to a distortion of the crystal structure and to improvement of the electrophysical parameters of the piezoceramics. This is due to the formation of a phase which has a higher symmetry, but at high concentrations of iron (>0.4 wt%), it leads to sharp degradation of electrophysical parameters. PMID:25073145

Bykov, Igor; Zagorodniy, Yuriy; Yurchenko, Lesya; Korduban, Alexander; Nejezchleb, Karel; Trachevsky, Vladimir; Dimza, Vilnis; Jastrabik, Lubomir; Dejneka, Alexander

2014-08-01

14

Phase evolution studies of sol-gel derived lead zirconate titanate (PZT) nanopowder using X-ray diffraction and X-ray photoelectron spectroscopy  

NASA Astrophysics Data System (ADS)

We report here the formation of single phase lead zirconate titanate (PZT) nanopowder with composition Pb(Zr0.52Ti0.48)O3 and average crystallite size 12-20 nm, synthesized by sol-gel process. The phase evolution of PZT gel powder, heat treated at temperatures 550, 650 and 800°C was monitored by X-ray diffraction (XRD) and X-ray photo-electron spectroscopy (XPS). The high resolution XPS spectra of Pb4f, Zr3d, Ti2p and O1s show that PZT with pure perovskite structure is obtained at 800°C while at lower temperatures pyrochlore phase co-exists with perovskite phase. The XRD results also support this analysis. We have also identified the pyrochlore phase using XPS by analyzing the corresponding variations in the FWHM values, peak positions and the separation between the spin doublets of Pb, Zr and Ti associated with it. The composition of the final powder obtained with pure perovskite structure is calculated and is close to the designed value.

Sachdeva, Anupama; Kumar, Mahesh; Luthra, Vandna; Tandon, R. P.

2011-07-01

15

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

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

16

Lead zirconate titanate films on metallic substrates by electrophoretic deposition  

Microsoft Academic Search

Electrophoretic deposition (EPD) of submicrometer lead zirconate titanate (PZT) particles was conducted to form thick PZT films (up to 80?m thickness) on different metallic substrates, including stainless steel plates, individual fibres, fibre mats and nichrome wires. Non-aqueous colloidal suspensions suitable for EPD were prepared by mixing ultrasonically 0.5g of PZT particles in 50ml acetylacetone with controlled addition of iodine. The

S. Y. Ng; A. R. Boccaccini

2005-01-01

17

Microstereolithography of lead zirconate titanate thick film on silicon substrate  

Microsoft Academic Search

The microstereolithography (?SL) of lead zirconate titanate (PZT) thick films on platinum-buffered silicon substrates is reported for the first time in this paper. Crack-free PZT thick films (80–130 ?m thick) have been fabricated by laser direct-write UV polymerization from the HDDA-based UV curable PZT suspensions. The characterization of the fired films shows dielectric permittivities of 120–200, tangent loss of 0.92–2.5%

X. N. Jiang; C. Sun; X. Zhang; B Xu; Y. H Ye

2000-01-01

18

Fabrication of Microdevices Using Bulk Ceramics of Lead Zirconate Titanate  

NASA Astrophysics Data System (ADS)

Piezoelectric microdevices using lead zirconate titanate (PZT) bulk ceramics are desired for use in actuators requiring a large driving force. We have designed a fabrication process for microdevices using PZT bulk ceramics together with Si single crystals. The key techniques of the process are the bonding of PZT bulk ceramics to Si single crystals, the thinning of bulk ceramics, and the micromachining of bulk ceramics. PZT ceramics were bonded to Si using a gold thin film as an intermediate layer. The tensile strength of the PZT-Si bonded wafers depended on the PZT poling process. A dicer or a KrF excimer laser was used to cut the PZT ceramics along the designed pattern. A PZT-Si diaphragm was fabricated as an example of a basic structure that can be used in a device such as a piezoelectric micropump.

Tanaka, Katsuhiko; Konishi, Takahiro; Ide, Masato; Meng, Zhicong; Sugiyama, Susumu

2005-09-01

19

Dielectric properties of lead zirconate titanate thin films seeded with barium strontium titanate nanoparticles  

Microsoft Academic Search

A low temperature synthetic method recently proposed by the authors was applied to the fabrication of lead zirconate titanate (PZT) thin films containing crystalline seeds of barium strontium titanate (BST) nanoparticles. PZT precursor and the BST particles were prepared with complex alkoxide methods. Precursor solution suspending the BST particles was spin-coated on Pt\\/Ti\\/SiO2\\/Si substrate to film thickness of 500–800 nm

Tomokazu Tanase; Yoshio Kobayashi; Toshihide Nabatame; Takao Miwa; Mikio Konno

2005-01-01

20

Lead Zirconate Titanate (LZT) Ceramics.  

National Technical Information Service (NTIS)

A method of producing homogeneous, fully reacted lead zirconate titanate powder, including additive elements, by reaction of the oxides of the constituent metals in a molten salt solvent was developed. Ceramics fired from different batches of powder made ...

J. H. Rosolowski R. H. Arendt J. W. Szymaszek

1979-01-01

21

Lead Zirconate Titanate (LZT) Ceramics.  

National Technical Information Service (NTIS)

A method of producing fully reacted, homogeneous lead zirconate titanate powders including all the technologically important property modifying additives is described. The method involves reacting mixture of powders of the components together with a eutec...

J. H. Rosolowski R. H. Arendt J. W. Szymaszek

1977-01-01

22

Fabrication and dielectric properties of barium strontium titanate nano-particles\\/amorphous lead zirconate titanate composite thin film  

Microsoft Academic Search

A low temperature synthetic method, which combines metal–organic decomposition and a nm-seeding technique, was applied to the fabrication of barium strontium titanate (BST) nano-particle\\/amorphous lead zirconate titanate (PZT) composite thin films. A metal–organic solution of PZT was mixed with a suspension of BST nano-crystalline particles to prepare a precursor solution. The mixed solution was spin-coated on a Pt\\/Ti\\/SiO2\\/Si substrate and

Tomokazu Tanase; Yoshio Kobayashi; Takao Miwa; Mikio Konno

2005-01-01

23

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

Microsoft Academic Search

Millimeter-wave magnetoelectric interactions have been studied through electric field effects on magnetic excitations in bilayers of single crystal barium ferrite and lead zirconate titanate (PZT). An electric field E produces a mechanical deformation in PZT, resulting in a shift deltaf in the frequency for electromagnetic modes in the ferrite. Reflected power versus frequency profiles at 40-55 GHz for a series

G. Srinivasan; I. V. Zavislyak; A. S. Tatarenko

2006-01-01

24

Lead Zirconate Titanate Nanowire Growth Via Spin Coating in Conjunction with Sol-Gel Process  

Microsoft Academic Search

Lead zirconate titanate (PZT) nanowires are successfully synthesized by a spin coating of sol-gel solution on a highly ordered porous alumina membrane (PAM). Field emission scanning electron microscope images show that PZT nanowires are well packed inside the nanochannels of the PAM. A selected area electron diffraction pattern reveals that they are polycrystalline. They exhibit a high aspect-ratio (up to

Jongok Kim; Yong Chan Choi; Ki-Seog Chang; Sang Don Bu

2007-01-01

25

Lead zirconate titanate behaviors in an LDMOS  

NASA Astrophysics Data System (ADS)

The behaviors of lead zirconate titanate (PZT) deposited as the dielectric for high-voltage devices are investigated experimentally and theoretically. The devices demonstrate not only high breakdown voltages above 350 V, but also excellent memory behaviors. A drain current—gate voltage (ID—VG) memory window of about 2.2 V is obtained at the sweep voltages of ±10 V for the 350-V laterally diffused metal oxide semiconductor (LDMOS). The retention time of about 270 s is recorded for the LDMOS through a controlled ID—VG measurement. The LDMOS with memory behaviors has potential to be applied in future power conversion circuits to boost the performance of the energy conversion system.

Zhai, Ya-Hong; Li, Wei; Li, Ping; Li, Jun-Hong; Hu, Bin; Huo, Wei-Rong; Fan, Xue; Wang, Gang

2013-07-01

26

Quality factor of micro cantilevers transduced by piezoelectric lead zirconate titanate film  

Microsoft Academic Search

The quality factors (Q-factor) of micro cantilevers transduced by piezoelectric lead zirconate titanate (PZT) film under atmospheric pressure conditions\\u000a were investigated and discussed. It was found that Q-factors increased with thicker PZT film. Due to air damping, shorter cantilevers resulted in preferred larger Q-factors. The Q-factor was found to be as high as 450 for a 150-?m long PZT cantilever

Jian Lu; Tsuyoshi Ikehara; Takeshi Kobayashi; Ryutaro Maeda; Takashi Mihara

2007-01-01

27

Plasma-sprayed lead zirconate titanate-glass composites  

SciTech Connect

A plasma-spray process was used to produce piezoelectric lead zirconate titanate (PZT)-glass composite thick films. The films were found to have the same crystal structure as the PZT (Navy-type V) and lead-based glass starting powder mixture. The films showed good adhesion to stainless steel and silver-coated glass slides and poor adhesion to aluminum substrates. The dielectric constant of the films varied between 58 and 20 with dissipations between 0.019 and 0.032. The films were poled, and their piezoelectric charge coefficient, d[sub 33], was 1.1 pC/N.

Sherrit, S.; Savin, C.R.; Wiederick, H.D.; Mukherjee, B.K. (Royal Military Coll. of Canada, Kingston, Ontario (Canada). Dept. of Physics); Prasad, S.E. (Sensor Technology, Ltd., Collingwood, Ontario (Canada))

1994-07-01

28

Dielectrophoretic assembly of lead zirconate titanate microtubes  

NASA Astrophysics Data System (ADS)

Lead zirconate titanate (PZT) microtubes were assembled onto pre-patterned substrates using dielectrophoresis of a colloidal suspension of microtubes dispersed in isopropyl alcohol. High aspect ratio tubes with an outer diameter of 2 ?m and length of about 30 ?m were prepared by vacuum infiltration of mesoporous silicon templates. An interdigitated electrode structure with gap sizes ranging from 2 ?m to 15 ?m was patterned on a silicon substrate via conventional lithography. This allowed a non-uniform alternating electric field to be generated. The influence of the electrode gap along with the effects of the waveform, amplitude and frequency of an applied signal on the dielectrophoretic assembly of PZT microtubes was investigated. A square wave signal of 5 V and 10 Hz was found to be the most effective in assembling the microtubes on a 12 ?m electrode gap. The results show potential for the dielectrophoretic technique in realizing integrated 3D devices using the high aspect ratio piezoelectric tube structures as building blocks.

Koval, V.; Bharadwaja, S. S. N.; Li, M.; Mayer, T. S.; Trolier-McKinstry, S.

2011-12-01

29

Nanodomains in morphotropic lead zirconate titanate ceramics: On the origin of the strong piezoelectric effect  

NASA Astrophysics Data System (ADS)

The outstanding piezoelectric properties of lead zirconate titanate (PZT) ceramics with compositions close to the morphotropic phase boundary of the quasibinary phase diagram of lead zirconate and lead titanate are still under debate. A combination of ex situ and in situ transmission electron microscopy and high resolution x-ray diffraction revealed that the extrinsic piezoelectric effect in morphotropic PZT is closely connected to the existence of nanodomains. The in situ transmission electron microscopy investigations with applied electric field show that mainly the nanodomains respond to the electric field while the microdomain structure does not change noticeably in our experiments.

Theissmann, Ralf; Schmitt, Ljubomira A.; Kling, Jens; Schierholz, Roland; Schönau, Kristin A.; Fuess, Hartmut; Knapp, Michael; Kungl, Hans; Hoffmann, Michael J.

2007-07-01

30

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

SciTech Connect

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

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

2008-04-15

31

Selectively Nucleated Lateral Crystallization of Lead Zirconate Titanate Thin Films Using Titanium Island Seed Layer  

Microsoft Academic Search

We have investigated the selectively nucleated lateral crystallization (SNLC) of lead zirconate titanate (PZT) thin film using a titanium seed. The titanium island seed layer was formed on Pt(200 nm)\\/SiO2(500 nm)\\/Si by radio frequency magnetron sputtering and lift-off process at room temperature. Selectively nucleated lateral crystallization happened at 570°C and a rectangular array of PZT single grains was formed after

JONG-IN YUN; NAM-KYU SONG; SEUNG-KI JOO

2004-01-01

32

Bending Actuator Using Lead Zirconate Titanate Thin Film Fabricated by Hydrothermal Method  

Microsoft Academic Search

Thin films of lead zirconate titanate (PZT) were fabricated by the hydrothermal method which consisted of two steps in the hydrothermal process: ``nucleation'' and ``crystal growth'' processes. The PZ nuclei were formed by the reaction at 140°C in a solution containing 4N potassium hydroxide. The growth rate of PZT crystals decreased at temperatures below and above 120°C. Bimorph-type bending actuators

Takayuki Kikuchi; Takaaki Tsurumi; Yoko Ohba; Masaki Daimon

1992-01-01

33

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

Microsoft Academic Search

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

Patamas Bintachitt

2009-01-01

34

Development of lead zirconate titanate cantilevers on the micrometer length scale  

Microsoft Academic Search

The objective of this research project was to fabricate a functional ferroelectric microcantilever from patterned lead zirconate titanate (PZT) thin films. Cantilevers fabricated from ferroelectric materials have tremendous potential in sensing applications, particularly due to the increased sensitivity that miniaturized devices offer. This thesis highlights and explores a number of the processing issues that hindered the production of a working

Christopher Robert Martin

2005-01-01

35

Energy Dissipation Mechanisms in Lead Zirconate Titanate Thin Film Transduced Micro Cantilevers  

Microsoft Academic Search

A high quality factor (Q-factor) is most desirable for resonant mass sensors because their sensitivity greatly depends on the detectable frequency shift after mass adsorption. The authors fabricated lead zirconate titanate (PZT) thin film transduced micro cantilevers and studied the energy dissipation mechanisms to better understand the essential aspects affecting the Q-factor. It was found that energy dissipation induced by

Jian Lu; Tsuyoshi Ikehara; Yi Zhang; Ryutaro Maeda; Takashi Mihara

2006-01-01

36

Fabrication of Lead Zirconate Titanate Films by Inkjet Printing  

NASA Astrophysics Data System (ADS)

In this study, a finely patterned lead zirconate titanate (PZT) film is fabricated by a combination of inkjet printing (IJP), chemical solution deposition (CSD), and surface energy controlling technology. We used patterned multilayer lower electrodes, which easily enable high surface energy contrast on the lower electrode area and achieved high accuracy patterning in the inkjet deposition process. The PZT film, which can be used as an actuator, has 2 ?m thickness after iterating the set of surface treatment, inkjet deposition, and baking. This film has a dielectric constant (\\varepsilonr) of 1700, loss tangent (\\tan?) of 0.05, remanent polarization (Pr) of 10 ?C/cm2, and coercive field (Ec) of 23 kV/cm. Piezoelectric coefficient d31 estimated from a displacement of the membrane was determined to be 77 pm/V. These results suggest that this method is a candidate for piezo microelectromechanical system (MEMS) fabrication.

Machida, Osamu; Shimofuku, Akira; Tashiro, Ryo; Takeuchi, Atsushi; Akiyama, Yoshikazu; Ohta, Eiichi

2012-09-01

37

Neutron diffraction studies on recrystallization of solution derived lead zirconate titanates  

SciTech Connect

We performed neutron powder diffraction on solution-derived lead zirconate titanates (PZT). Three compositions, PZT 45/55, PZT 20/80 and PbTiO{sub 3}, were investigated. The materials were annealed so that the perovskite phase had just begun to grow from the precursor phase. In our materials this precursor phase is the pyrochlore rather than fluorite phase. The results show that in the pyrochlore phase, the (Ti,Zr) and the Pb are ordered in their crystallographic sites while the O are essentially disordered in both of the two usual pyrochlore anion sites.

Morosin, B.; Tuttle, B.A.; Voigt, J.A. [Sandia National Labs., Albuquerque, NM (United States); Lawson, A.C. [Los Alamos National Lab., NM (United States); Kwei, G.H. [Lawrence Livermore National Lab., CA (United States)

1994-12-31

38

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

NASA Astrophysics Data System (ADS)

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.

Tang, Haixiong; Malakooti, Mohammad H.; Sodano, Henry A.

2013-11-01

39

Electrooptic Properties of Epitaxial Lead Zirconate Titanate Films on Silicon Substrates  

NASA Astrophysics Data System (ADS)

Electrooptic (EO) properties and propagation losses of the lead zirconate titanate (PZT) films grown on silicon (Si) substrates have been investigated. PZT films were prepared on Si substrates by chemical solution method. Refractive index changes and propagation losses of PZT films were evaluated by prism coupling method. A (100)-oriented 8.9-?m-thick epitaxial PZT film grown on a Si substrate with strontium ruthenium oxide/ceria/yttria-stabilized zirconia (SRO/CeO2/YSZ) epitaxial buffer layer was found to have large EO effect and very low propagation loss. Propagation of an infrared light with a wavelength of 1550 nm into a PZT film on Si substrate was successfully confirmed.

Kurihara, Kazuaki; Kondo, Masao; Sato, Keisuke; Ishii, Masatoshi; Wakiya, Naoki; Shinozaki, Kazuo

2007-10-01

40

Dielectric and pyroelectric properties of lead zirconate titanate/polyurethane composites  

SciTech Connect

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.

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

41

Electrostriction of lead zirconate titanate/polyurethane composites  

SciTech Connect

Electrostriction of a ferroelectric inclusion/nonferroelectric matrix composite system was studied. The samples were prepared by blending the lead zirconate titanate (PZT) particles with the thermoplastic polyurethane through extrusion and subsequently by hot pressing. Quasistatic cyclic electric fields were applied across the samples while strains and currents were monitored simultaneously. It was found that the electrostriction of the composites depended on the applied electric field in a hysteretic manner. In particular at the high-field regime, the samples exhibited a reversal in the electrostrictive strain. This switching effect occurred at a critical field which was inversely proportional to the PZT content. An associated increase in the displacement current with the critical field was also observed. It indicates that the switching in strain of the composites was mainly due to the flipping of the PZT dipoles in the nonferroelectric polymer matrix. A model was developed for describing the electrostriction behavior of this composite system and the calculated results are comparable to the experimental curves. The success of this theoretical model encourages its application further to the ferroelectric-ferroelectric composite systems.

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

2005-05-15

42

Helmholtz Resonator for Lead Zirconate Titanate Acoustic Energy Harvester  

NASA Astrophysics Data System (ADS)

Acoustic energy harvesters that function in environments where sound pressure is extremely high (~150 dB), such as in engine rooms of aircrafts, are expected to be capable of powering wireless health monitoring systems. This paper presents the power generation performances of a lead-zirconate-titanate (PZT) acoustic energy harvester with a vibrating PZT diaphragm. The diaphragm had a diameter of 2 mm, consisting of Al(0.1 ?m)/PZT(1 ?m)/Pt(0.1 ?m)/Ti(0.1 ?m)/SiO2(1.5 ?m). The harvester generated a power of 1.7×10-13 W under a sound pressure level of 110 dB at the first resonance frequency of 6.28 kHz. It was found that the generated power was increased to 6.8×10-13 W using a sound-collecting Helmholtz resonator cone with the height of 60 mm. The cone provided a Helmholtz resonance at 5.8 kHz, and the generated power increased from 3.4×10-14 W to 1.4×10-13 W at this frequency. The cone was also effective in increasing the bandwidth of the energy harvester.

Matsuda, Tomohiro; Tomii, Kazuki; Hagiwara, Saori; Miyake, Shuntaro; Hasegawa, Yuichi; Sato, Takamitsu; Kaneko, Yuta; Nishioka, Yasushiro

2013-12-01

43

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

Microsoft Academic Search

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

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

2008-01-01

44

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

Microsoft Academic Search

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

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

2008-01-01

45

Preparation, Microstructure, and Ferroelectric Properties of Laser-Deposited Thin Batio sub3 and Lead Zirconate-Titanate Films.  

National Technical Information Service (NTIS)

Ferroelectric thin films of BaTiO3 and lead zirconate titanate, PbZro.53Tio.4703 (PZT), have been prepared by pulsed excimer laser deposition. The microstructure and crystallography of these films have been studied by scanning electron microscopy (SEM), e...

P. S. Brody B. J. Rod K. W. Bennett L. P. Cook P. K. Schenck

1991-01-01

46

Magnetoelectric CoFe2O4-lead zirconate titanate thick films prepared by a polyvinylpyrrolidone-assisted sol-gel method  

Microsoft Academic Search

Magnetoelectric CoFe2O4-PZT (lead zirconate titanate) films as thick as 1 mum have been prepared by spin coating using a PZT sol-gel solution containing polyvinylpyrrolidone and CoFe2O4 powder. X-ray diffraction result reveals that there exists no chemical reaction or phase diffusion between the CoFe2O4 and PZT phases. The scanning electron microscopy observation confirms that the composite thick film is crack-free and

Jian-Guo Wan; Hao Zhang; Xiuwei Wang; Dengyu Pan; Jun-Ming Liu; Guanghou Wang

2006-01-01

47

Power generation and shunt damping performance of a single crystal lead magnesium niobate-lead zirconate titanate unimorph: Analysis and experiment  

Microsoft Academic Search

This letter investigates the power generation and shunt damping performance of the single crystal piezoelectric ceramic lead magnesium niobate-lead zirconate titanate (PMN-PZT) analytically and experimentally. PMN-PZT is a recently developed interface for energy harvesting and shunt damping with its large piezoelectric constant (-2252 pm\\/V) and coupling coefficient (0.95) for the transverse piezoelectric mode. A unimorph PMN-PZT cantilever with an aluminum

A. Erturk; O. Bilgen; D. J. Inman

2008-01-01

48

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

NASA Astrophysics Data System (ADS)

Millimeter-wave magnetoelectric interactions have been studied through electric field effects on magnetic excitations in bilayers of single crystal barium ferrite and lead zirconate titanate (PZT). An electric field E produces a mechanical deformation in PZT, resulting in a shift ?f in the frequency for electromagnetic modes in the ferrite. Reflected power versus frequency profiles at 40-55 GHz for a series of bias magnetic field and E=0-10 kV/cm along the c axis of the ferrite showed an increase in ?f to a maximum of 8 MHz. Theoretical estimates of ?f are in agreement with the data.

Srinivasan, G.; Zavislyak, I. V.; Tatarenko, A. S.

2006-10-01

49

Changes in chemical behavior of thin film lead zirconate titanate during Ar +-ion bombardment using XPS  

NASA Astrophysics Data System (ADS)

Thin film lead zirconate titanate (PZT) was grown on Pt/TiO 2/SiO 2/Si substrates using direct liquid injection metal organic chemical vapor deposition (DLI-MOCVD). The chemical states and stoichiometry was characterized by employing X-ray photoelectron spectroscopy (XPS). The discussion was focused on the chemical change during in-depth profile by Ar +-ion bombardment. In addition, relative atomic sensitivity factors (ASFs) were corrected to determine practically more accurate chemical compositions in the thin film PZT. And then, the chemical compositions by their application to quantification were compared with other data using the data base of Wagner ASFs and Scofield ASFs.

Kim, Jae-Nam; Shin, Kwang-Soo; Kim, Dae-Hwan; Park, Byung-Ok; Kim, Nam-Kyoung; Cho, Sang-Hee

2003-02-01

50

Fatigue anisotropy in lead-zirconate-titanate  

Microsoft Academic Search

Bipolar fatigue in bulk lead-zirconate-titanate ceramics is known to induce a severe loss of switchable polarization and strong asymmetries of strain hysteresis in cycling direction. An investigation into the transverse functional dependencies is conducted here. The polarization hysteresis perpendicular to the cycling direction only loses 35% amplitude after 2·107 cycles (compared to 80% in cycling direction). The strain in this

Doru C. Lupascu; Cyril Verdier

2004-01-01

51

Fabrication and electrical properties of lead zirconate titanate thick films by the new sol–gel method  

Microsoft Academic Search

Lead zirconate titanate (Pb(Zr0.53Ti0.47)O3, PZT) ferroelectric films with 2–60 ?m in thickness have been successfully fabricated on Pt-coated oxidized Si substrates(Pt\\/Ti\\/SiO2\\/Si) by a new sol–gel based 0-3 method. The films consisted of 0-3 ceramic\\/ceramic composites formed by dispersing nanopowders in a PZT solution. The precursor solution for spin coating was prepared from lead acetate, tetrabutyl titanate, and zirconium nitrate. The

Donglin Xia; Meidong Liu; Yike Zeng; Churong Li

2001-01-01

52

Photoreduction of silver salts on highly heterogeneous lead zirconate titanate  

Microsoft Academic Search

This paper presents the work undertaken to determine the influences on the photo-induced growth of silver nanoclusters on the surfaces of lead zirconate titanate thin films. The lead zirconate titanate films were grown on indium tin oxide coated glass. They exhibited a highly textured surface and can be treated as wide bandgap semiconductors that exhibit ferroelectric behaviour. We show that

P. M. Jones; S. Dunn

2007-01-01

53

Self-limiting behavior of the grain growth in lead zirconate titanate thin films  

NASA Astrophysics Data System (ADS)

During the lateral grain-growth process in lead zirconate titanate (PZT) thin films by selectively nucleated lateral crystallization using PZT seed, it was found that the lateral growth was saturated with the annealing temperature. The saturation of lateral growth was analyzed by the interface energy, which appeared during the crystallization process. The factors affecting the saturation of lateral growth were found to be the interface energy between the perovskite phase and the pyrochlore phase, and the one between the PZT thin film and the bottom Pt electrode. When the ion damage was introduced to the growth-saturated PZT thin films, further lateral growth was observed. Pt bottom electrode thickness was changed to control the interface energy between the PZT thin film and the Pt bottom electrode. PZT grain size increased according to the Pt thickness, because the lattice parameter of Pt films increased with the thickness of the Pt films. The incubation time for nucleation in the PZT thin films increased with the amount of the ion damage on the Pt films.

Lee, Jang-Sik; Joo, Seung-Ki

2002-09-01

54

Fabrication of lead zirconate titanate actuator via suspension polymerization casting  

NASA Astrophysics Data System (ADS)

The research presented herein has focused on the fabrication of a lead zirconate titanate (PZT) telescopic actuator from Suspension Polymerization Casting (SPC). Two systems were studied: an acrylamide-based hydrogel, and an acrylate-based nonaqueous system. Analytical tools such as thermomechanical analysis (TMA), differential scanning calorimetry (DSC), chemorheology, thermogravimetric analysis (TGA), and differential thermal analysis (DTA) were used to investigate the polymerization and burnout processes. The acrylamide hydrogel polymerization casting process used hydroxymethyl acrylamide (HMAM) monofunctional monomer with methylenebisacrylamide (MBAM) difunctional monomer, or used methacrylamide (MAM) as monofunctional monomer. High solid loading PZT slurries with low viscosities were obtained by optimizing the amounts of dispersant and the PZT powders. The overall activation energy of gelation was calculated to be 60--76 kJ/mol for the monomer solution, this energy was increased to 91 kJ/mol with the addition of PZT powder. The results show that the PZT powder has a retardation effect on gelation. Although several PZT tubes were made using the acrylamide-based system, the demolding and drying difficulties made this process unsuitable for building internal structures, such as the telescopic actuator. The acrylate-based system was used successfully to build telescopic actuator. Efforts were made to study the influence of composition and experimental conditions on the polymerization process. Temperature was found to have the largest impact on polymerization. To adjust the polymerization temperature and time, initiator and/or catalyst were used. PZT powder has a catalytic effect on the polymerization process. Compared with acrylamide systems, acrylate provided a strong polymer network to support the ceramic green body. This high strength is beneficial for the demolding process, but it can easily cause cracks during the burnout process. To solve the burnout issue, non-reactive decalin was used as a solvent to lower the stress inside the green body. The addition of decalin has no large impact on the polymerization process. With 15 wt% decalin in the monomer solution, the burnout process was successfully solved. The burnout process was monitored by TGA/DTA and TMA. A 51 vol% PZT filled acrylate slurry was cast into a mold made by Stereolithography (SLA), and after curing, the telescopic actuator was removed from the mold. This indirect SLA method provides an efficient way to build ceramic parts. PZT samples were sintered at 1275°C for 4 hours, with density over 98%. SEM analysis showed the sample made by SPC has a uniform microstructure, which may be beneficial to the electric properties. The sample made by polymerization has a d33 value about 680 pm/V, which is better than the literature value (580 pm/V). The electric tests showed this telescopic actuator produced a maximum deflection of 24.7 mum at 250 kV/m, in line with theoretical calculations. Compared with actuators made by other methods, the actuator made by SPC provides a comparable structural factor (187.5). The distortion in actuators is caused by fabrication and sintering.

Miao, Weiguo

2000-10-01

55

Effect of (Mn, F) and (Mg, F) co-doping on dielectric and piezoelectric properties of lead zirconate titanate ceramics  

NASA Astrophysics Data System (ADS)

The influence of (Mn, F) and (Mg, F) dopants on the piezoelectric properties of lead zirconate titanate (PZT) ceramic compositions close to the morphotropic phase boundary is investigated. PZT ceramics are prepared by a chemical route based on co-precipitation of oxalates and hydroxides. The acceptor is incorporated into the B site of the materials and the fluorine ion is introduced into anionic sites. The d33 coefficient, the mechanical quality factor Qm and other properties are measured. Scanning electron microscopy is used to determine the grain size of the materials. Electron spin resonance is used to determine the valency state of Mn in fluorinated PZT ceramics. In Mn doped PZT, the introduction of a fluorine ion makes the poling process easier and increases the piezoelectric coefficients whereas the fluorination of Mg doped PZT constantly leads to hard materials with a lower piezoelectric response. This study shows that (Mn, F) co-doping produces semihard materials with high piezoelectric coefficients.

Boucher, E.; Guyomar, D.; Lebrun, L.; Guiffard, B.; Grange, G.

2002-11-01

56

Secrets of PZT  

Microsoft Academic Search

Lead zirconate titanate, Pb(Zr,Ti)O3 or PZT, is the best known and most important piezoelectric material. During the fifty years since its discovery its structure and properties have been studied in a great detail. Despite these efforts and the fact that PZT is used in innumerable devices its properties are still not well understood. PZT is not (widely) available in form

Dragan Damjanovic

2008-01-01

57

Investigation of piezoelectric softening mechanisms in lead zirconate titanate using diffraction and property measurements  

NASA Astrophysics Data System (ADS)

Lead zirconate titanate (PZT) is a well-known piezoelectric ceramic of commercial and scientific importance. Typically, PZT is used in its doped form as doping allows its properties to be tailored for specific applications. Donor doping turns PZT into a "soft" ferroelectric. One of the characteristics of soft ferroelectrics is an increase in their longitudinal piezoelectric coefficient. Softening is currently attributed to an increase in the concentration of lead vacancies and the associated effect on the behavior of ferroelectric domain walls. However, the exact mechanism by which donor doping enhances the longitudinal piezoelectric coefficient is still not understood. In this work, the crystallographic response of donor-doped PZT is studied in situ during the application of electric fields in order to deduce the strain mechanisms which contribute to ferroelectric softening. X-ray diffraction from a synchrotron source is employed for this investigation. It was found that the use of different donor dopants results in distinctive, characteristic strain mechanisms that soften PZT. Sm and Nd aid in the softening of PZT solely by enhancing 90° domain wall mobility. However, La and Nb doping results in a material with coexisting ferroelectric phases. It was further found that Nb doping results in at least two additional strain mechanisms including interphase boundary motion and a large strain in the (200) rhombohedral lattice plane. As piezoelectrics are also used in high temperature applications, the temperature dependence of the piezoelectric coefficient in soft doped PZT was also investigated. It was found that Sm doping leads to a high temperature (?300°C) piezoelectric coefficient that is substantially greater than that found in La and Nb-doped PZT. In some cases, the coefficient in Sm-doped PZT is greater than that of La and Nd-doped PZT by a factor of two. Conventionally, the largest piezoelectric coefficient values are obtained in soft doped PZT by using a Zr:Ti ratio close to the morphotropic phase boundary (MPB). It is shown that in Sm-doped PZT, enhanced high temperature piezoelectric coefficients can also be obtained at compositions far from the MPB due to the presence of a mixed tetragonal and cubic phase. The mixed phase is hypothesized to enable a larger extrinsic piezoelectric response in Sm doped PZT due to enhanced strain accommodation in the coexisting polymorphic phases. In summary, it is presented that dopants yield signature, qualitative softening mechanisms, contributing differently to high piezoelectricity in PZT. The results suggest that in contrast to prior-held assumptions, an increase in Pb vacancies is not a necessary criterion for softening.

Seshadri, Shruti B.

58

Effect of Pb Content on Electric Properties of Sol-Gel Derived Lead Zirconate Titanate Thin Films Prepared by Three-Step Heat-Treatment Process  

Microsoft Academic Search

Lead zirconate titanate (PZT) thin films were fabricated by a three-step heat-treatment process which involves the addition of -10, 0 and 10 mol% excess Pb to the starting solution and spin coating onto Pt\\/Ti\\/SiO2\\/Si substrates. Crystalline phases as well as preferred orientations in PZT films were investigated by X-ray diffraction analysis (XRD). The microstructure and composition of the films were

Zhan-jie Wang; Ryutaro Maeda; Kaoru Kikuchi

1999-01-01

59

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

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

60

Study of impedance parameters of cerium modified lead zirconate titanate ceramics  

Microsoft Academic Search

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

Balgovind Tiwari; R. N. P. Choudhary

2010-01-01

61

Dielectric properties and phase transition of polycrystalline lead zirconate titanate lead cobalt niobate  

Microsoft Academic Search

The binary system of lead zirconate titanate [Pb(Zr1\\/2Ti1\\/2)O3, PZT] and lead cobalt niobate [Pb(Co1\\/3Nb2\\/3O3, PCoN] was fabricated using a high temperature solid state reaction method. The structure and homogeneity of the ceramics obtained have been investigated using x-ray diffraction. The morphology of the ceramics was characterized by scanning electron microscopy (SEM). The results indicated that the presence of PCoN in

Naratip Vittayakorn; Tawee Tunkasiri

2007-01-01

62

Structural heterogeneity and diffuse scattering in morphotropic lead zirconate-titanate single crystals.  

PubMed

Complementary diffuse and inelastic synchrotron x-ray scattering measurements of lead zirconate-titanate single crystals with composition near the morphotropic phase boundary (x=0.475) are reported. In the temperature range 293 KPZT at its morphotropic phase boundary is essentially structurally inhomogeneous. PMID:23002887

Burkovsky, R G; Bronwald, Yu A; Filimonov, A V; Rudskoy, A I; Chernyshov, D; Bosak, A; Hlinka, J; Long, X; Ye, Z-G; Vakhrushev, S B

2012-08-31

63

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

NASA Astrophysics Data System (ADS)

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.

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

2010-10-01

64

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

NASA Astrophysics Data System (ADS)

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 C, H and F were formed and remained on the etched surface while no titanium fluoride was formed during the etching process. The major factor that restricts the realization of a high etching rate is the removal of PbF2. Fluoride that remained on the surface could be removed by annealing after etching.

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

2000-01-01

65

Dielectric properties and phase transition of polycrystalline lead zirconate titanate lead cobalt niobate  

NASA Astrophysics Data System (ADS)

The binary system of lead zirconate titanate [Pb(Zr1/2Ti1/2)O3, PZT] and lead cobalt niobate [Pb(Co1/3Nb2/3O3, PCoN] was fabricated using a high temperature solid state reaction method. The structure and homogeneity of the ceramics obtained have been investigated using x-ray diffraction. The morphology of the ceramics was characterized by scanning electron microscopy (SEM). The results indicated that the presence of PCoN in the solid solution decreases the structural stability of PZT perovskite phase. A transition from tetragonal to pseudo-cubic phase was observed as PCoN increased and the co-existence of tetragonal-pseudo-cubic phases occurred at composition with x = 0.3. The permittivity showed a ferroelectric to paraelectric phase transition at 236 °C with a maximum value = 39 000 at 100 Hz at the morphotropic phase boundary (MPB) composition.

Vittayakorn, Naratip; Tunkasiri, Tawee

2007-12-01

66

Wave propagation modeling of the PZT sensing region for structural health monitoring  

Microsoft Academic Search

Despite various successful applications of lead zirconate titanate (PZT) material for structural health monitoring (SHM), the fundamental research work of determining the PZT sensing region is still needed. Among a variety of issues in relation to the PZT sensing region, this paper focuses on one of the most important factors, the material and structural damping. The elasticity solution of PZT

Yuhang Hu; Yaowen Yang

2007-01-01

67

Biaxial Flexural Strength of Poled Lead Zirconate Titanate under High Electric Field with Extended Field Range  

SciTech Connect

In the present work, as-received poled lead zirconate titanate, or PZT 5A, was examined using ball-on-ring (BoR) mechanical testing coupled with an electric field. Electric fields in the range of 4Ec (Ec, coercive field) with controlled loading paths were applied, and mechanical tests at a substantial number of characteristic electric field levels were conducted. Commercial electronic liquid FC-40 was used to prevent the setup from dielectric breakdown under a high electric field. Weibull strength distribution was used to interpret the mechanical strength data. The data showed that the strength levels of the PZT-5A tested under OC (open circuit) in air and in FC-40 were almost the same. It was further revealed that , for the studied cases, the effect of loading history on the biaxial flexural strength of the PZT was significant in -Ec, but not in OC or zero field as well as 4Ec . An asymmetry V curve was observed for the characteristic strength-electric field graph, and the bottom of V curve was located near the negative coercive field. Microscopy analysis showed that surface-located volume-distributed flaws were the strength limiter and responsible for the failure of the tested PZT under electromechanical loadings.

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

2013-01-01

68

Lead zirconate titanate thin films for piezoelectric actuation and sensing of MEMS resonators  

NASA Astrophysics Data System (ADS)

This research is focused on examining the potential benefits and limitations of applying sol-gel lead zirconate titanate (PZT) piezoelectric thin films to on-chip piezoelectrically driven RF microelectromechanical system (MEMS) resonators in the low frequency (LF) to very high frequency (VHF) frequency range. MEMS fabrication methods are presented for fabricating PZT-based MEMS resonator structures along with investigations into the resultant thin film residual stresses and material properties, and their impact on resonator frequency, beam curvature, and resonant mode shape. The PZT, silicon dioxide (SiO2), platinum (Pt), and silicon nitride (Si3N4) thin film material properties are characterized and validated by wafer bow, cantilever resonance, cantilever thermal-induced tip deflection and finite element modeling (FEM) techniques. The performance of the fabricated PZT-based MEMS resonators are presented and compared to previously demonstrated zinc oxide (ZnO) based resonators as well as to electrostatically based MEMS resonator designs. Resonators with frequency response peaks of greater than 25 dB, quality factors up to 4700, and resonant frequencies up to 10 MHz are demonstrated along with a discussion of their advantages and disadvantages for use as MEMS resonators. Nonlinear resonator response is also investigated in relation to the onset of classic Duffing behavior, beam buckling and mode coupling. Fabrication techniques, operating conditions, and design rules are presented to minimize or eliminate nonlinear resonator response.

Piekarski, Brett Harold

69

Thickness dependence of structure and piezoelectric properties at nanoscale of polycrystalline lead zirconate titanate thin films  

NASA Astrophysics Data System (ADS)

Lead zirconate titanate Pb(Zr0.50Ti0.50)O3 (PZT) thin films were deposited by a polymeric chemical method on Pt(111)/Ti/SiO2/Si substrates to understand the mechanisms of phase transformations and the effect of film thickness on the structure, dielectric, and piezoelectric properties in these films. PZT films pyrolyzed at temperatures higher than 350 °C present a coexistence of pyrochlore and perovskite phases, while only perovskite phase grows in films pyrolyzed at temperatures lower than 300 °C. For pyrochlore-free PZT thin films, a small (100)-orientation tendency near the film-substrate interface was observed. Finally, we demonstrate the existence of a self-polarization effect in the studied PZT thin films. The increase of self-polarization with the film thickness increasing from 200 nm to 710 nm suggests that Schottky barriers and/or mechanical coupling near the film-substrate interface are not primarily responsible for the observed self-polarization effect in our films.

Araújo, E. B.; Lima, E. C.; Bdikin, I. K.; Kholkin, A. L.

2013-05-01

70

Effect of Annealing on Fatigue Properties of Sb-Doped Lead Zirconate Titanate Thin Films Deposited by DC Reactive Sputtering  

NASA Astrophysics Data System (ADS)

The effect of annealing on the ferroelectric properties ofPt-based thin film capacitors of Sb-doped lead zirconate titanate[Pt/Pb(Zr0.48Ti0.52)O3/Pt/SiO2/Si] wereinvestigated. Undoped Pb(Zr0.48Ti0.52)O3 (PZT0) andSb-doped Pb(Zr0.48Ti0.52)O3 (PZST07) thin films wereannealed in oxygen atmosphere at 650°C for 30 min. The Sbcation in a PZT thin film before and after annealing was confirmedto be trivalent (Sb3+) by X-ray photoelectron spectroscopy(XPS). The grain sizes of undoped PZT (PZT0) and Sb-doped PZT(PZST07) thin films after annealing are seen to increase. Thesechanges of grain size affect the fatigue properties of PZT thinfilms. Annealed Sb-doped PZT (PZST07) thin films show good fatiguebehavior (fatigue free up to 1011 switching cycles) and alarger P*r-P?r value (31 µC/cm2) than SrBi2Ta2O9 (SBT) thin films.

Choi, Won-Youl; Kim, Ho-Gi

1999-01-01

71

Heterogeneity of fatigue in bulk lead zirconate titanate  

Microsoft Academic Search

The spatial heterogeneity of fatigue in commercial ferroelectric lead zirconate titanate ceramics was experimentally investigated. All parameters measured on fatigued samples are spatially highly heterogeneous including large signal polarisation and strain hysteresis loops (remnant polarisation Pr, coercive field Ec, bias field Ebias, and strain asymmetry ?) as well as the small signal parameters determined from field dependent converse piezoelectric measurements

Yong Zhang; Doru C. Lupascu; Emil Aulbach; Ivan Baturin; Andrew Bell; Jürgen Rödel

2005-01-01

72

Stability of pinning centers in fatigued lead-zirconate-titanate  

Microsoft Academic Search

After bipolar electric fatigue of bulk lead-zirconate-titanate ceramics, the well known reduced remnant polarization values are observed as well as an asymmetric strain hysteresis reflecting a macroscopic offset polarization. Thermal treatment and high electric fields each liberate the domain system from the microscopic defects responsible for the macroscopic offsets. High electric fields (4 Ec) only allow one to remove the

Jürgen Nuffer; Doru C. Lupascu; Jürgen Rödel

2002-01-01

73

Fatigue studies in compensated bulk lead zirconate titanate  

Microsoft Academic Search

Impedance analysis studies were carried out on compensated bulk lead zirconate titanate samples. Fatigue is concomitant with the onset of dielectric loss. This is shown to be dominantly due to an irreversibly modified near-surface layer that can be polished off. The highly compensated nature of these samples minimizes the role of oxygen vacancies.

Cyril Verdier; Finlay D. Morrison; Doru C. Lupascu; James F. Scott

2005-01-01

74

Fatigue studies in compensated bulk lead zirconate titanate  

SciTech Connect

Impedance analysis studies were carried out on compensated bulk lead zirconate titanate samples. Fatigue is concomitant with the onset of dielectric loss. This is shown to be dominantly due to an irreversibly modified near-surface layer that can be polished off. The highly compensated nature of these samples minimizes the role of oxygen vacancies.

Verdier, Cyril; Morrison, Finlay D.; Lupascu, Doru C.; Scott, James F. [Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany); Department of Earth Sciences, Cambridge University, Cambridge (United Kingdom); Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany); Department of Earth Sciences, Cambridge University, Cambridge (United Kingdom)

2005-01-15

75

Thickness profiles through fatigued bulk ceramic lead zirconate titanate  

Microsoft Academic Search

Wedge-cut samples of fatigued ferroelectric lead zirconate titanate ceramics were investigated using piezoresponse force microscopy in conjunction with conventional electrical hysteresis measurements. The local clamping of domains is monitored at different depths in the sample. The coercive fields in grains near the electrodes differ for different materials and preparation methods of the electrodes. For silver, fatigue consistently generates a space

Nina Balke; Doru C. Lupascu; Thomas Blair; Alexei Gruverman

2006-01-01

76

Study of pinched loop characteristics of lead zirconate titanate (65/35)  

SciTech Connect

We report the effect of processing parameters such as (1) uniaxial and (2) isostatic pressings on ferroelectric behavior of lead zirconate titanate (PZT) having Zr/Ti ratio 65/35. The effect of temperature (-125-250 deg.C) on pinched loop characteristics of uniaxially pressed PZT is also reported. Polycrystalline ceramic samples were synthesized by solid-state reaction technique and sintered at 1250 deg.C. The density was estimated to be 7.63 and 7.58 g/cc for the uniaxially and isostatically pressed samples, respectively, prepared by conventional ball milling. X-ray diffraction analysis confirmed single phase formation with rhombohedral structure. All samples pressed uniaxially and isostatically showed pinched hysteresis loops at room temperature that disappear at higher temperatures. The remnant polarization (P{sub r}) and coercive field (E{sub o}) for the uniaxially pressed samples become well defined in magnitude and shape at higher measurement temperatures below phase transition temperature (T{sub c}), but at low temperatures a distorted-loop-like structure was observed indicating low polarization properties. The effect of ferroelectric switching cycles on the PZT samples with and without annealing in oxygen is also discussed.

Pandey, S. K.; Thakur, O. P.; Kumar, Anand; Prakash, Chandra; Chatterjee, Ratnamala; Goel, T. C. [Electroceramics Group, Solid State Physics Laboratory, Lucknow Road, Delhi 110 054 (India); Department of Physics, Indian Institute of Technology Delhi, New Delhi 110 016 (India); Birla Institute of Technology and Science, Pilani, Goa Campus, Goa 403726 (India)

2006-07-01

77

A statistical model approximation for perovskite solid-solutions: A Raman study of lead-zirconate-titanate single crystal  

NASA Astrophysics Data System (ADS)

Lead titanate (PbTiO3) is a classical example of a ferroelectric perovskite oxide illustrating a displacive phase transition accompanied by softening of a symmetry-breaking mode. The underlying assumption justifying the soft-mode theory is that the crystal is macroscopically sufficiently uniform that a meaningful free energy function can be formed. In contrast to PbTiO3, experimental studies show that the phase transition behaviour of lead-zirconate-titanate solid solution (PZT) is far more subtle. Most of the studies on the PZT system have been dedicated to ceramic or powder samples, in which case an unambiguous soft-mode study is not possible, as modes with different symmetries appear together. Our Raman scattering study on titanium-rich PZT single crystal shows that the phase transitions in PZT cannot be described by a simple soft-mode theory. In strong contrast to PbTiO3, splitting of transverse E-symmetry modes reveals that there are different locally ordered regions. The role of crystal defects, random distribution of Ti and Zr at the B-cation site and Pb ions shifted away from their ideal positions, dictates the phase transition mechanism. A statistical model explaining the observed peak splitting and phase transformation to a complex state with spatially varying local order in the vicinity of the morphotropic phase boundary is given.

Frantti, J.; Fujioka, Y.; Puretzky, A.; Xie, Y.; Ye, Z.-G.; Glazer, A. M.

2013-05-01

78

A statistical model approximation for perovskite solid-solutions: a Raman study of lead-zirconate- titanate single crystal  

SciTech Connect

Lead titanate (PbTiO3) is a classical example of a ferroelectric perovskite oxide illustrating a displacive phase transition accompanied by a softening of a symmetry-breaking mode. The underlying assumption justifying the soft-mode theory is that the crystal is macroscopically sufficiently uniform so that a meaningful free energy function can be formed. In contrast to PbTiO3, experimental studies show that the phase transition behaviour of lead-zirconate-titanate solid solution (PZT) is far more subtle. Most of the studies on the PZT system have been dedicated to ceramic or powder samples, in which case an unambiguous soft-mode study is not possible, as modes with different symmetries appear together. Our Raman scattering study on titanium-rich PZT single crystal shows that the phase transitions in PZT cannot be described by a simple soft-mode theory. In strong contrast to PbTiO3, splitting of transverse E-symmetry modes reveals that there are different locally-ordered regions. The role of crystal defects, random distribution of Ti and Zr at the B- cation site and Pb ions shifted away from their ideal positions, dictates the phase transition mechanism. A statistical model explaining the observed peak splitting and phase transformation to a complex state with spatially varying local order in the vicinity of the morphotropic phase boundary is given.

Frantti, Johannes [Aalto University, Finland; Fujioka, Y [Aalto University, Finland; Puretzky, Alexander A [ORNL; Xie, Y [Simon Fraser University, Canada; Glazer, A [Clarendon Laboratory, Department of Physics, University of Oxford

2013-01-01

79

CO 2 laser-induced structure changes in lead zirconate titanate Pb(Zr 0.58Ti 0.42)O 3 sol-gel films  

NASA Astrophysics Data System (ADS)

Based on absorption spectra of lanthanum modified lead zirconate titanate Pb 0.9La 0.1(Zr 0.65Ti 0.35)O 3 (PLZT10/65/35) ferroelectric ceramics an idea of local and selective treatment of lead zirconite titanate Pb(Zr XTi 1- X)O 3 (PZT) sol-gel film in the multi-layer structure by CO 2 laser radiation was formulated. The possibility to obtain PZT perovskite film on the SiO 2/Si substrate by irradiation with CO 2 laser was shown experimentally. X-ray studies revealed the PZT perovskite structure ratio growth at the expenses of pirochlore structure with an increased power density of laser radiation.

Knite, Maris; Mezinskis, Gundars; Shebanovs, Leonids; Pedaja, Irina; Sternbergs, Andris

2003-03-01

80

Pb(Zr,Ti)O3 (PZT) fibers: Fabrication and measurement methods  

Microsoft Academic Search

Fine scale lead zirconate titanate (PZT) and niobium substituted PZT (Nb-PZT) piezoelectric fibers were fabricated from sol-gel processed viscous 'sol' using the 'spinning' methodology developed for the continuous production of glass fibers. Subsequent drying and firing at above 750 C gave pure perovskite PZT and Nb-PZT fibers of 30 micron in average diameter. Further densification and grain growth were evident

Shoko Yoshikawa; Ulagaraj Selvaraj; Paul Moses; John Witham; Richard Meyer; Thomas Shrout

1995-01-01

81

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

SciTech Connect

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.

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

82

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

SciTech Connect

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

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

2012-01-01

83

Substrate clamping effects on irreversible domain wall dynamics in lead zirconate titanate thin films.  

PubMed

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. PMID:22587285

Griggio, F; Jesse, S; Kumar, A; Ovchinnikov, O; Kim, H; Jackson, T N; Damjanovic, D; Kalinin, S V; Trolier-McKinstry, S

2012-04-13

84

Single-target DC-pulsed deposition of lead zirconate titanate thin films: Investigation of the chemical and mechanical properties by glow-discharge optical emission spectroscopy and nanoindentation  

Microsoft Academic Search

Reactive sputtering of a single metallic target in a pulsed DC mode is a promising approach for a fast and cost-efficient deposition of thin lead zirconate titanate (PZT) films on an industrial scale. Rapid depth profiling of the coatings is necessary for an efficient optimization of the process parameters. We demonstrate in this paper that glow-discharge optical emission spectroscopy is

P. Schwaller; A. Fischer; R. Thapliyal; M. Aeberhard; J. Michler; H. J. Hug

2005-01-01

85

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

NASA Astrophysics Data System (ADS)

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.

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

2013-07-01

86

Monitoring of the strength gain of concrete using embedded PZT impedance transducer  

Microsoft Academic Search

Piezoelectric lead zirconate titanate (PZT) impedance transducer in the electro-mechanical impedance (EMI) technique has emerged as a potential sensing tool for structural health monitoring. In the EMI technique, PZT acts as both sensor and actuator simultaneously due to its direct and inverse piezoelectric effects. The PZT impedance transducer provides a new alternative for monitoring the compressive strength gain of concrete

Dansheng Wang; Hongping Zhu

2011-01-01

87

Unipolar fatigue of ferroelectric lead–zirconate–titanate  

Microsoft Academic Search

In multilayer actuators the ferroelectric material is known to degrade under bipolar and to some degree under unipolar electric loading. Fatigue effects due to unipolar cycling of a commercial bulk lead–zirconate–titanate up to 4·108 cycles at 2 Ec are demonstrated. Unipolar as well as bipolar polarisation and strain hysteresis loops are measured after fatigue. Bipolar measurements after cycling show a

C Verdier; D. C Lupascu; J Rödel

2003-01-01

88

Lead zirconate titanate-lead silicate piezoelectric glass-ceramics  

Microsoft Academic Search

Piezoelectric glass-ceramics consisting of lead zirconate titanate in a lead silicate matrix have been developed. A small region of compositions in this system yield the desired combination of glass formability, densification and crystallization behavior, and piezoelectric properties. SiO2 is required for glass formability, while excess PbO allows low temperature processing. The amounts of these constitutes are limited by the optimization

B. Houng; M. J. Haun

1994-01-01

89

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

SciTech Connect

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

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

2010-05-15

90

Effect of Zr/Ti Ratio on Crystal Structure of Thin Lead Zirconate-Titanate Films Prepared by Reactive Sputtering  

NASA Astrophysics Data System (ADS)

Thin lead zirconate-titanate (PZT) films have been synthesized on MgO(100) using the tripole magnetron sputtering system. This system makes it possible to sputter lead and zirconium-titanium alternately. Lead concentration in the deposited films can be easily adjusted to near stoichiometry through the control of substrate temperature. The c-axis-oriented films with perovskite structure of Morphotropic Phase Boundary composition were obtained at 550°C via the self-limiting process of lead concentration. The formation process of thin PZT films has been investigated with reference to the observed results of the dependence of the crystal structure on Zr/Ti ratio as well as lead concentration in the films.

Fujisawa, Akira; Furihata, Masahiro; Minemura, Isamu; Onuma, Yoshio; Fukami, Tatsuo

1993-09-01

91

Frequency and field dependence of magnetoelectric interactions in layered ferromagnetic transition metal-piezoelectric lead zirconate titanate  

NASA Astrophysics Data System (ADS)

The strength of magnetoelectric (ME) coupling at 10 Hz-3 MHz has been measured in trilayers of Fe, Co, or Ni and lead zirconate titanate (PZT). The strongest ME coupling is measured for trilayers with Ni and the weakest in Co. Data on ME voltage coefficient ?E versus bias magnetic field H for Fe-PZT-Fe show unique features including zero crossing and sign reversal. Measurements of frequency dependence of ?E reveal a giant ME coupling due to the electromechanical resonance at 200-300 kHz for radial modes and at ~2.7 MHz for thickness modes. Theoretical estimates of field and frequency dependence of ?E are in very good agreement with the data.

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

2005-11-01

92

Development of lead zirconate titanate cantilevers on the micrometer length scale  

NASA Astrophysics Data System (ADS)

The objective of this research project was to fabricate a functional ferroelectric microcantilever from patterned lead zirconate titanate (PZT) thin films. Cantilevers fabricated from ferroelectric materials have tremendous potential in sensing applications, particularly due to the increased sensitivity that miniaturized devices offer. This thesis highlights and explores a number of the processing issues that hindered the production of a working prototype. PZT is patterned using soft lithography-inspired techniques from a PZT chemical precursor solution derived by the chelation synthesis route. As the ability to pattern ceramic materials derived from sol-gels on the micrometer scale is a relatively new technology, this thesis aims to expand the scientific understanding of new issues that arise when working with these patterned films. For example, the use of Micromolding in Capillaries (MIMIC) to pattern the PZT thin films results in the evolution of topographical distortions from the shape of the original mold during the shrinkage of patterned thin film during drying and sintering. The factors that contribute to this effect have been explained and a new processing technique called MicroChannel Molding (muCM) was developed. This new process combines the advantages of soft lithography with traditional silicon microfabrication techniques to ensure compatibility with current industrial practices. This work lays the foundation for the future production of working ferroelectric microcantilevers. The proposed microfabrication process is described along with descriptions of each processing difficulty that was encountered. Modifications to the process are proposed along with the descriptions of alternative processing techniques that were attempted for the benefit of future researchers. This dissertation concludes with the electronic characterization of micropattemed PZT thin films. To our knowledge, the ferroelectric properties of patterned PZT thin films have never been directly characterized before. The properties are measured with a commercial ferroelectric test system connected through a conductive Atomic Force Microscope tip. The films patterned by MIMIC and muCM are compared to large-area spin cast films to identify the role that the processing method has on the resulting properties.

Martin, Christopher Robert

93

Investigation of the additive induced doping effects in gelcast soft lead zirconate titanate ceramics  

SciTech Connect

Due to the high sensitivity of the electrical properties of electronic ceramics to various factors, knowledge about the possible influence of the processing procedure on their electrical performance is critical for applying a new technique to the fabrication of the materials. In this study, various electrical parameters, complex impedance spectra, ferroelectric hysteresis loops, and microstructures of soft lead zirconate titanate (PZT) ceramics formed by the gelcasting technique from suspensions with various dispersants were investigated in comparison with those of the conventional dry pressed ones. We found that the sodium ion, which is the main cation in many commercial surfactants, exhibited obvious hard doping effects; thus causing deteriorated performance of the gelcast PZT ceramics. While a certain impurity ion introduced by a dispersant was also found to induce soft doping characteristics and improve the electrical performance of the materials. The results suggest that the doping effects of the metal ions or impurities introduced by the dispersants, or other additives, should be generally considered for applying a wet processing technique to forming multicomponent electronic ceramics.

Guo Dong; Cai Kai; Li Longtu; Gui Zhilun [Department of Materials Science and Engineering, State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084 (China)

2009-09-01

94

Phase transition revealed by Raman spectroscopy in screen-printed lead zirconate titanate thick films  

NASA Astrophysics Data System (ADS)

The transition from rhombohedral phase to tetragonal in screen-printed lead zirconate titanate (PZT) thick films was studied using Raman-scattering spectroscopy, and the results were compared with those of x-ray-diffractometry investigations. The unfired films were subjected to rapid firing in an air atmosphere at temperatures ranging from 960 to 1150 C. During firing the composition of the films changed gradually as lead evaporated, which moved the composition of films to the ZrO2-PZT region and resulted in precipitation of ZrO2. This caused the original rhombohedral structure to be converted to tetragonal. Correspondingly, the Raman spectra also changed with increasing firing temperature. The variation in Raman spectra was characterized by three frequency regions, denoted as the low-, intermediate-, and high-frequency region, respectively, which are related to three cubic T(sub 1u) modes. Moreover, it was also observed that the appearance of tetragonal modes was delayed from the formation of tetragonal structure during the process. This discrepancy suggested the existence of a certain 'mismatch' in structure.

Zhang, Hongxue; Uusimaki, Antti; Leppavuori, Seppo; Karjalainen, Pentti

1994-10-01

95

Preparation and electrical properties of 1-3 PZT fiber\\/IPNs piezoelectric composites  

Microsoft Academic Search

Lead zirconate titanate\\/IPN piezoelectric composites with 1-3 connectivity consisting in Interpenetrating Polymer Networks (IPN) matrix and Lead Zirconate Titanate (PZT) fibers with length of 50um fabricated by the sol-gel route were prepared through solution mixing method. The process of PZT gel fibers formed and the changes of crystal grain sizes during thermal treatment were traced and analyzed by TG-DTA and

J. Liu; D. Y. Tang; X. L. Wu; Y. J. Qiao

2007-01-01

96

Power generation and shunt damping performance of a single crystal lead magnesium niobate-lead zirconate titanate unimorph: Analysis and experiment  

NASA Astrophysics Data System (ADS)

This letter investigates the power generation and shunt damping performance of the single crystal piezoelectric ceramic lead magnesium niobate-lead zirconate titanate (PMN-PZT) analytically and experimentally. PMN-PZT is a recently developed interface for energy harvesting and shunt damping with its large piezoelectric constant (-2252 pm/V) and coupling coefficient (0.95) for the transverse piezoelectric mode. A unimorph PMN-PZT cantilever with an aluminum substrate is tested under base excitation and its electromechanical response is predicted with a coupled distributed parameter model. The power generation performance of the device is 138 ?W/(g2 cm3) at 1744 Hz, causing 84% tip vibration attenuation due to the resistive shunt damping effect.

Erturk, A.; Bilgen, O.; Inman, D. J.

2008-12-01

97

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

NASA Astrophysics Data System (ADS)

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

Bintachitt, Patamas

98

Directed colloidal assembly and characterization of PZT-polymer composites  

Microsoft Academic Search

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 (phisolids > 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 phi PZT

James Earl Smay

2002-01-01

99

Comparison of lead Zirconate Titanate thin films for microelectromechanical energy harvester with interdigitated and parallel plate electrodes.  

PubMed

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

Chidambaram, N; Mazzalai, A; Balma, D; Muralt, P

2013-08-01

100

Liquid-phase sintering of PZT ceramics  

Microsoft Academic Search

Lead zirconate titanate (abbreviated as PZT) ceramics are of considerable commercial importance for a host of piezoelectric and pyroelectric applications. Conventionally, many PZT ceramics are sintered at temperatures above 1250°C. Such extreme temperatures are undesirable due to the increased energy consumption, limitation of electrode material and evaporation of volatile components. A liquid-phase sintering aid incorporating Cu2O and PbO is presented

D. L Corker; R. W Whatmore; E Ringgaard; W. W Wolny

2000-01-01

101

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

SciTech Connect

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

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

2005-04-01

102

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

NASA Astrophysics Data System (ADS)

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

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

2005-04-01

103

Develop Techniques for Ion Implantation of PLZT (Lead-Lanthanum-Zirconate-Titanate) for Adaptive Optics.  

National Technical Information Service (NTIS)

Research was conducted at Pacific Northwest Laboratory to develop high photosensitivity adaptive optical elements utilizing ion implanted lanthanum-doped lead-zirconate-titanate (PLZT). One centimeter square samples were prepared by implanting ferroelectr...

C. R. Batishko J. L. Brimhall W. T. Pawlewicz K. A. Stahl L. H. Toburen

1987-01-01

104

Real-Time Salmonella Detection Using Lead Zirconate Titanate-Titanium Microcantilevers.  

National Technical Information Service (NTIS)

Current methods for analysis of unknown powders in suspicious packages involve sending samples to laboratory facilities where a variety of time-consuming tests are performed. We have developed and investigated the use of a lead zirconate titanate - titani...

I. Chaiken, J. McGovern, M. Sergi, W. Shih, W. Y. Shih

2005-01-01

105

Study of Temperature Stability of Properties of Lead Zirconate Titanate Piezoceramic.  

National Technical Information Service (NTIS)

A study of the effects of temperature on properties of several compounds of the lead zirconate titanate system was made. Compounds that have higher temperature stability were determined. A study was made of changes in their properties under the simultaneo...

G. N. Vitalinskaya V. A. Doroshenko M. A. Ugryumova

1976-01-01

106

Orientation of rapid thermally annealed lead zirconate titanate thin films on (111) Pt substrate.  

National Technical Information Service (NTIS)

The nucleation, growth and orientation of lead zirconate titanate thin films prepared from organometallic precursor solutions by spin coating on (111) oriented platinum substrates and crystallized by rapid thermal annealing was investigated. The effects o...

K. G. Brooks I. M. Reaney R. Klissurska Y. Huang L. A. Bursill

1994-01-01

107

Effect of manganese doping on the size effect of lead zirconate titanate thin films and the extrinsic nature of 'dead layers'.  

PubMed

We have investigated the size effect in lead zirconate titanate (PZT) thin films with a range of manganese (Mn) doping concentrations. We found that the dynamic size effect in the conventional Pt/PZT/Pt thin-film capacitors could be systematically reduced and almost completely eliminated by increasing Mn doping concentration. The interfacial layer at the electrode-film interface appears to disappear almost entirely for the PZT films with ? 2% Mn doping levels, confirmed by the fits using the conventional 'in-series capacitor' model. Our work indicates that the dynamic size effect in ferroelectrics is extrinsic in nature, supporting the work by Saad et al. Other implications of our results have also been discussed. By comparing a variety of experimental studies in the literature we propose a scenario that the 'dead layer' between PZT (or barium strontium titanate, BST) and metal electrodes such as Pt and Au might have a defective pyrochlore/fluorite-like structure (possibly with a small portion of ferroelectric perovskite phase). This scenario is then generalized by including the effect of the grain-boundary dead layer on the collapse of the dielectric constant in thinner films. PMID:21386350

Lou, X J; Wang, J

2010-02-10

108

Effect of manganese doping on the size effect of lead zirconate titanate thin films and the extrinsic nature of 'dead layers'  

NASA Astrophysics Data System (ADS)

We have investigated the size effect in lead zirconate titanate (PZT) thin films with a range of manganese (Mn) doping concentrations. We found that the dynamic size effect in the conventional Pt/PZT/Pt thin-film capacitors could be systematically reduced and almost completely eliminated by increasing Mn doping concentration. The interfacial layer at the electrode-film interface appears to disappear almost entirely for the PZT films with ~2% Mn doping levels, confirmed by the fits using the conventional 'in-series capacitor' model. Our work indicates that the dynamic size effect in ferroelectrics is extrinsic in nature, supporting the work by Saad et al. Other implications of our results have also been discussed. By comparing a variety of experimental studies in the literature we propose a scenario that the 'dead layer' between PZT (or barium strontium titanate, BST) and metal electrodes such as Pt and Au might have a defective pyrochlore/fluorite-like structure (possibly with a small portion of ferroelectric perovskite phase). This scenario is then generalized by including the effect of the grain-boundary dead layer on the collapse of the dielectric constant in thinner films.

Lou, X. J.; Wang, J.

2010-02-01

109

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

NASA Astrophysics Data System (ADS)

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

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

2006-04-01

110

Lead zirconate titanate nanoscale patterning by ultraviolet-based lithography lift-off technique for nano-electromechanical system applications.  

PubMed

The advantage of using lead zirconate titanate (PbZr(0.54)Ti(0.46)O(3)) ceramics as an active material in nanoelectromechanical systems (NEMS) comes from its relatively high piezoelectric coefficients. However, its integration within a technological process is limited by the difficulty of structuring this material with submicrometer resolution at the wafer scale. In this work, we develop a specific patterning method based on optical lithography coupled with a dual-layer resist process. The main objective is to obtain sub-micrometer features by lifting off a 100-nm-thick PZT layer while preserving the material's piezoelectric properties. A subsequent result of the developed method is the ability to stack several layers with a lateral resolution of few tens of nanometers, which is mandatory for the fabrication of NEMS with integrated actuation and read-out capabilities. PMID:23007767

Guillon, Samuel; Saya, Daisuke; Mazenq, Laurent; Costecalde, Jean; Rèmiens, Denis; Soyer, Caroline; Nicu, Liviu

2012-09-01

111

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

112

Temperature dependence of a PZT piezoelectric sensor for Mercury Dust Monitor up to 150 °C  

Microsoft Academic Search

We have been developing a cosmic dust detector for BepiColombo Mercury exploration mission, called Mercury Dust Monitor (MDM). The MDM uses piezoelectric sensors made of lead zirconate titanate (PZT) ceramics for estimation of dust flux and momentum of incident particles. The PZT sensors of MDM, installed on the surface of a side panel of the MMO without a sunshade, will

Takeo Iwai

2008-01-01

113

Stress dependence of reversible and irreversible domain switching in PZT during cyclic loading  

Microsoft Academic Search

Stresses suffered by lead zirconate titanate (PZT) components in actuators are the origin of the gradual degradation of the microstructure and piezoelectric capability that limits their lifetime. The stress–strain behavior of a PZT ceramic has been studied in compressive uniaxial cyclic loading using a constant loading rate, in order to determine the operating stresses that cause structural damage associated to

Jose M Calderon-Moreno; Monica Popa

2002-01-01

114

Low Frequency Magnetoelectric Coupling in Bilayers of Lead Zirconate Titanate and Sol-gel Derived Lanthanum Strontium Manganite  

NASA Astrophysics Data System (ADS)

Layered composites of ferromagnetic-piezoelectric oxides show a giant magnetoelectric effect (ME) at low frequencies [1]. This work is on ME coupling in bilayers of lead zirconate titanate (PZT) and La0.7Sr0.3MnO3 (LSMO). Discs of LSMO were made by hot-pressing and sintering of powder obtained by sol-gel techniques. The bilayers were made by bonding LSMO and PZT discs. The ME voltage coefficient ?E=?E/?H were estimated from the measured induced electric field ?E in the presence of an ac field ?H and a bias field H. Key results are as follows. (i) The maximum ?E of 50-60 mV/cm Oe at room temperature is obtained for transverse fields and for LSMO sintered at 1600 K. (ii) ?E is found to be temperature independent. (iii) The ME coupling for longitudinal fields is an order of magnitude smaller than for transverse fields. (iv) Theoretical estimates based on a model for bilayers are in qualitative agreement with the data [2]. 1. G. Srinivasan, E. T. Rasmussen, J. Gallegos, R. Srinivasan, Yu. I. Bokhan, and V. M. Laletin, Phys. Rev. B 64, 214408 (2001). 2. G. Srinivasan, E. T. Rasmussen, B. J. Levin, and R. Hayes, Phys. Rev.B 65, 134402 (2002). *work supported by a grant from the NSF (0302254).

Yang, Wei

2005-03-01

115

Effect of Uniaxial Stress on Dielectric Properties of 0–3 PZT-Portland Cement Composite  

Microsoft Academic Search

The effects of uniaxial stress on the 0–3 lead zirconate titanate (PZT)-portland cement (PC) composite were investigated. PZT and PC composites were fabricated using 50% of PZT by volume. At room temperature, the dielectric properties were measured under stress free and stress level up to 57 MPa at the frequency of 1–100 kHz. The results showed that the dielectric constant

N. Jaitanong; R. Yimnirun; A. Chaipanich

2009-01-01

116

Bias Field Effects on Microwave Frequency Behavior of PZT\\/YIG Magnetoelectric Bilayer  

Microsoft Academic Search

Magnetoelectric behavior of a yttrium iron garnet (YIG)\\/zirconate titanate (PZT) magnetoelectric bilayer composite was studied over 1-7 GHz under different bias magnetic fields and electric fields by using a broadband air-gap microstrip with the PZT\\/YIG loaded in the air gap. Electrostatically induced ferrimagnetic resonance (FMR) frequency shifts of the YIG\\/PZT bilayer composite were studied. The FMR frequency shift was negligible

Carl Pettiford; Saumitro Dasgupta; Jin Lou; Soack D. Yoon; N. X. Sun

2007-01-01

117

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

118

Detection of indentation induced Fe-to-Afe phase transformation in lead zirconate titanate.  

SciTech Connect

Instrumented indentation was combined with microscopy and spectroscopy analysis to investigate the local mechanically induced ferroelectric to anti-ferroelectric phase transformation of niobium-modified lead zirconate titanate 95/5. Indentation experiments to a depth of 2 {micro}m were performed using a Berkovich pyramidal three-sided diamond tip. Subsequent Raman spectroscopy and piezoelectric force microscopy revealed that indentation locally induced the ferroelectric to antiferroelectric phase transformation. Piezoelectric force microscopy demonstrated the ability to map the individual phases within and near indented regions on the niobium-modified lead zirconate titanate ceramics.

Baddorf, Arthur P. (Oak Ridge National Laboratory, Oak Ridge, TN); Shin, Junsoo (Oak Ridge National Laboratory, Oak Ridge, TN); Gogotsi, Yury G. (Drexel University, Philadelphia, PA); Buchheit, Thomas Edward; Watson, Chad Samuel; Kalinin, Sergei (Oak Ridge National Laboratory, Oak Ridge, TN); Juliano, Thomas F. (Drexel University, Philadelphia, PA)

2005-08-01

119

Detection of Indentation Induced FE-to-AFE Phase Transformation in Lead Zirconate Titanate  

SciTech Connect

Instrumented indentation was combined with microscopy and spectroscopy analysis to investigate the local mechanically induced ferroelectric to anti-ferroelectric phase transformation of niobium-modified lead zirconate titanate 95/5. Indentation experiments to a depth of 2 {micro}m were performed using a Berkovich pyramidal three-sided diamond tip. Subsequent Raman spectroscopy and piezoelectric force microscopy revealed that indentation locally induced the ferroelectric to antiferroelectric phase transformation. Piezoelectric force microscopy demonstrated the ability to map the individual phases within and near indented regions on the niobium-modified lead zirconate titanate ceramics.

Baddorf, Arthur P [ORNL; Kalinin, Sergei V [ORNL; Shin, Junsoo [ORNL; Juliano, Thomas F. [Drexel University; Gogotsi, Yury G. [Drexel University; Buchheit, Thomas E. [Sandia National Laboratories (SNL); Watson, Chad S. [Sandia National Laboratories (SNL)

2006-01-01

120

Preparation and Characterization of PZT Thin Films  

SciTech Connect

In analogy with Piezoelectric Wafer Active Sensors (PWAS), Lead Zirconate Titanate (PZT) thin films also seem to be promising for Structural Health Monitoring (SHM) due to a number of reasons. Firstly, PZT thin films with well oriented domains show enhanced piezoelectric response. Secondly, PWAS requires comparatively large voltage leading to a demand for thin PZT films (<< {mu}m in thickness) for low voltage operation at {<=}10 V. This work focuses on two different aspects: (a) growing oriented PZT thin films in ferroelectric perovskite phase in the range of (80-150) nm thickness on epitaxial Si/Pt without a seed layer and (b) synthesizing perovskite phase in PZT thin films on Corning glass 1737 using a seed layer of TiO{sub x} (TiO{sub x} thickness ranging between 30 nm to 500 nm)

Bose, A.; Sreemany, M.; Bhattacharyya, D. K.; Sen, Suchitra [Central Glass and Ceramic Research Institute, CSIR, 196 Raja S.C. Mullick Road, Kolkata-700032 (India); Halder, S. K. [National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi-110012 (India)

2008-07-29

121

Damage evolution in ferroelectric PZT induced by bipolar electric cycling  

Microsoft Academic Search

The fatigue behaviour of commercial bulk Lead Zirconate Titanate (PZT) induced by bipolar cycling was investigated. Polarisation and strain hysteresis loops as well as acoustic emissions (AE) were monitored. Higher cycling fields (2×Ec) yield stronger fatigue, higher AE energy values and lower threshold values for the onset of AE events at high cycle numbers. AE amplitudes and energies were found

J Nuffer; D. C Lupascu; J Rödel

2000-01-01

122

Crack initiation and crack propagation in partially electroded PZT  

Microsoft Academic Search

For partially electroded piezoelectric materials, a strain incompatibility arises between the electrically active part and the electrically inactive part of the material. This can lead to crack initiation and crack propagation perpendicular to the electrode edge. In order to study crack initiation, a symmetrical geometry with the electrodes in the centre of the surfaces of thin lead zirconate titanate (PZT)

S. L dos Santos e Lucato; D. C Lupascu; J Rödel

2001-01-01

123

Screen Printed PZT Thick Films Using Composite Film Technology  

Microsoft Academic Search

A spin coating composite sol gel technique for producing lead zirconate titanate (PZT) thick films has been modified for use with screen printing techniques. The resulting screen printing technique can be used to produce 10 ?m thick films in a single print. The resultant films are porous but the density can be increased through the use of repeated sol infiltration\\/pyrolysis

R. A. Dorey; R. W. Whatmore; S. P. Beeby; R. N. Torah; N. M. White

2003-01-01

124

Lamb wave tuning curve calibration with improved PZT modeling  

Microsoft Academic Search

Guided waves generated and measured using surface-bonded Lead Zirconate Titanate (PZT) transducers have been widely used for structural health monitoring (SHM) and nondestructive testing (NDT) applications. For selective actuation and sensing of Lamb wave modes, the sizes of the transducers and the driving frequency of the input waveform should be tuned. For this purpose, a theoretical Lamb wave tuning curve

Sang Jun Lee; Hoon Sohn

2009-01-01

125

Interaction of PbZrxTi1-xO3 (PZT) with Ni: role of surface defects  

Microsoft Academic Search

The surface properties of lead zirconate titanate (PZT) and its interaction with a metallic overlayer have been investigated. X-ray photoelectron spectroscopy (XPS) was used to study the composition and chemical states of the substrate and adsorbate ions. Results in PZT were compared to those in iso-structural SrTiO3. It was found that, on polished PZT and SiTiO3 surfaces at room temperature,

S. M. Mukhopadhyay; T. C. S. Chen

1995-01-01

126

Raman study of lead zirconate titanate under uniaxial stress  

SciTech Connect

The authors used micro-Raman spectroscopy to monitor the ferroelectric (FE) to antiferroelectric (AFE) phase transition in PZT ceramic bars during the application of uniaxial stress. They designed and constructed a simple loading device, which can apply sufficient uniaxial force to transform reasonably large ceramic bars while being small enough to fit on the mechanical stage of the microscope used for Raman analysis. Raman spectra of individual grains in ceramic PZT bars were obtained as the stress on the bar was increased in increments. At the same time gauges attached to the PZT bar recorded axial and lateral strains induced by the applied stress. The Raman spectra were used to calculate an FE coordinate, which is related to the fraction of FE phase present. The authors present data showing changes in the FE coordinates of individual PZT grains and correlate these changes to stress-strain data, which plot the macroscopic evolution of the FE-to-AFE transformation. Their data indicates that the FE-to-AFE transformation does not occur simultaneously for all PZT grains but that grains react individually to local conditions.

TALLANT, DAVID R.; SIMPSON, REGINA L.; GRAZIER, J. MARK; ZEUCH, DAVID H.; OLSON, WALTER R.; TUTTLE, BRUCE A.

2000-04-01

127

Sol-gel preparation of PZT thin films with BaTiO3 seeds  

NASA Astrophysics Data System (ADS)

The lead zirconate titanate (PZT) thin films, with Zr/Ti ratio of 52/48 have been synthesized by the sol-gel method. Perovskite barium titanate (BaTiO3) nanopowders have been introduced in the precursor sols as seeds, to induce the perovskite phase formation at low temperatures. Their effect on the phase formation process, during the crystallization of PZT thin film was studied. Pure perovskite PZT thin films were obtained at 550 degrees Celsius and 600 degrees Celsius, when 5 mole% and 1 mole% perovskite BT crystalline seeds were used, respectively.

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

1998-02-01

128

Mechanical and Ferroelectric Behavior of PZT-Based Thin Films  

Microsoft Academic Search

The mechanical and ferroelectric behavior of freestanding lead zirconate titanate (PZT) -based thin film uni- morph structures for microelectromechanical systems was in- vestigated with uniaxial tension specimens of SiO2-TiPt-PZT-Pt, SiO2-TiPt-PZT, SiO2-TiPt, and individual SiO2 and Pt films. Full-field strains obtained with digital image correlation were used to compute the stress versus strain curves for each film combina- tion and the

Sivakumar Yagnamurthy; Ioannis Chasiotis; John Lambros; Ronald G. Polcawich; Jeffrey S. Pulskamp; Madan Dubey

2011-01-01

129

Phase Formation in PZT Phosphorus-Doped Ceramics  

SciTech Connect

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.

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

130

Field-induced antiferroelectric-ferroelectric phase switching behavior in lead strontium zirconate titanate ceramics  

NASA Astrophysics Data System (ADS)

Lead zirconate titanate (PZT) materials are used widely as transducers and actuators in a variety of applications. The phase diagram of PbZrO 3-PbTiO3-SrTiO3-SrZrO3 system (called PSZT) shows a long AFE-FE phase boundary suitable for field-induced phase transition study. Initially, the phase transitions in PSZT ceramics are studied to assist in understanding the effects of compositional modification on the relative stabilities of the AFE and FE phases. This yielded modified AFE-FE phase boundary for the PSZT family based on the polarization and structural information. The stabilization of the AFE phase by increasing Sr2+ and Zr 4+ content produced increased AFE-FE transition field and decreased polarization. Phase transitions with respect to temperature are investigated by means of polarization hysteresis and dielectric properties measurements. These observations are discussed in terms of Goldschmidt's tolerance factor and soft-mode theory. The entropy difference (DeltaS) during AFE-FE phase switching is calculated using a modified Clausius-Clapeyron approach. The dependence of the switching field on temperature (dE/dT) is found to be greater for the reverse switching than for forward phase transition. An explanation is provided in terms of the relative coupling strength of the domains. The longitudinal field-induced strain in the PSZT systems is in the range of 0.2%--0.5% indicating possibilities for creating large strain actuators using selected compositions. However, PSZT ceramics displayed degradation in polarization and field-induced strain with increasing number of the switching cycles. In order to increase the field-induced strain and reduce the remnant strain, composition PSZT 15/80/20 is doped with various amounts of La 3+ or Nd3+ (1--3 atom%). The stabilization of the AFE structure by La3+ or Nd3+ doping resulted in increased AFE FE phase transition field and decreased temperature of the maximum dielectric constant. The induced strain is maximized at 2 atom% La 3+ or Nd3+ doping with negligible remnant strain. Using innovative in situ x-ray diffraction technique, direct observations of the unit cell parameters of the AFE phase and subsequent electric field-induced FE phase of selected PSZT ceramics are preformed. This volume increase accounts for most of the large field-induced longitudinal strain during AFE-FE phase transition.

Yu, Yongjian

2000-11-01

131

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

PubMed

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

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

2012-05-30

132

Microemulsion Synthesis of Nanoparticle PZT Powder  

Microsoft Academic Search

Nanocrystalline lead zirconate titanate (PZT) powders have been synthesized using microemulsion processing route. Microemulsion is one of the major processing techniques to synthesize a nanosize, homogenous, and almost agglomerate free ceramic powders. The ternary microemulsion system is consisted of cyclohexane as the oil phase, Triton X100 as the nonionic surfactant phase, and an aqueous phase containing 0.619 M Pb2+, 0.325

M. Amiriyan; Z. A. Nemati; M. S. Rahmanifar; S. Ramesh; S. Meenaloshini; R. Tolouei

2011-01-01

133

Fabrication and piezoelectricity of 0–3 cement based composite with nano-PZT powder  

Microsoft Academic Search

Lead zirconate titanate (Pb(Zr0.52Ti0.48)O3) (PZT) nano-powder with a perovskite structure was fabricated using sol–gel process. The average crystallite diameter of the PZT powder is calculated to be 23.6nm and the average agglomerate size is about 200nm. The 0–3 cement based nano-PZT composites were obtained by pressing the mixture of white cement and the nano-PZT powders under a high pressure followed

Zongjin Li; Hongyu Gong; Yujun Zhang

2009-01-01

134

Biotemplated synthesis of PZT nanowires.  

PubMed

Piezoelectric nanowires are an important class of smart materials for next-generation applications including energy harvesting, robotic actuation, and bioMEMS. Lead zirconate titanate (PZT), in particular, has attracted significant attention, owing to its superior electromechanical conversion performance. Yet, the ability to synthesize crystalline PZT nanowires with well-controlled properties remains a challenge. Applications of common nanosynthesis methods to PZT are hampered by issues such as slow kinetics, lack of suitable catalysts, and harsh reaction conditions. Here we report a versatile biomimetic method, in which biotemplates are used to define PZT nanostructures, allowing for rational control over composition and crystallinity. Specifically, stoichiometric PZT nanowires were synthesized using both polysaccharide (alginate) and bacteriophage templates. The wires possessed measured piezoelectric constants of up to 132 pm/V after poling, among the highest reported for PZT nanomaterials. Further, integrated devices can generate up to 0.820 ?W/cm(2) of power. These results suggest that biotemplated piezoelectric nanowires are attractive candidates for stimuli-responsive nanosensors, adaptive nanoactuators, and nanoscale energy harvesters. PMID:24274657

Cung, Kellye; Han, Booyeon J; Nguyen, Thanh D; Mao, Sheng; Yeh, Yao-Wen; Xu, Shiyou; Naik, Rajesh R; Poirier, Gerald; Yao, Nan; Purohit, Prashant K; McAlpine, Michael C

2013-12-11

135

Role of defect distributions and mobility on ferroelectric phase transformations in lead zirconate titanate  

SciTech Connect

Studies of the influence of defect distributions and mobility on ferroelectric phase transformations in lead zirconate titanate have been performed by transmission electron microscopy, high resolution electron microscopy, polarization switching measurements, and dielectric spectroscopy. Investigations focused on La{sup 3+} and K{sup 1+} modified lead zirconate titanates. Defects which could be randomly quenched-in from temperatures significantly above that of the ferroelectric phase transformation resulted in relaxor ferroelectric behavior characterized by polar nanodomains. However, defects which remained mobile until temperatures significantly below that of the phase transformation resulted in a normal ferroelectric state which was characterized by domain pinning. Mobile impurities/vacancies are revealed to order into chain fragments or clusters which diffuse to domain boundaries resulting in a pinning of the boundaries on cooling. {copyright} {ital 1997 American Institute of Physics.}

Tan, Q.; Xu, Z.; Li, J.; Viehland, D. [Department of Materials Science and Engineering and Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)] [Department of Materials Science and Engineering and Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

1997-08-01

136

Lead zirconate titanate ferroelectric thin film capacitors: Effects of surface treatments on ferroelectric properties  

NASA Astrophysics Data System (ADS)

X-ray photoelectron spectroscopy (XPS) revealed a lead-rich carbonatelike surface layer on polycrystalline lead zirconate titanate films grown by metal-organic chemical vapor deposition. In situ XPS studies indicated that lead originally present in the oxide film reacted with Pt during its deposition, forming a Ti/Zr-rich defective interfacial layer. Lead zirconate titanate films that underwent a nitric acid treatment, which effectively removed the surface layer, exhibited a stretched out of the hysteresis loop in the vicinity of the coercive field, consistent with the presence of a nonferroelectric passive layer. Reasonable agreement between the XPS-measured interface layer thickness and the thickness determined by electrical characterization was obtained.

Chen, Ye; McIntyre, Paul C.

2007-08-01

137

Evolution of bias field and offset piezoelectric coefficient in bulk lead zirconate titanate with fatigue  

Microsoft Academic Search

Hysteresis loops of the piezoelectric coefficient, d33=f(E3), are measured on virgin and fatigued lead zirconate titanate ceramics. Four parameters are directly extracted from the measurements: internal bias field Eb, offset piezoelectric coefficient doffset, coercive field Ec, and remnant piezoelectric coefficient dr. The reduction in dr displays the decreasing switchable polarization with fatigue cycling. Eb and doffset are found to be

Yong Zhang; Ivan S. Baturin; Emil Aulbach; Doru C. Lupascu; Andrei L. Kholkin; Vladimir Ya. Shur; Jürgen Rödel

2005-01-01

138

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

Microsoft Academic Search

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

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

2005-01-01

139

Photo-reduction of silver salts on highly heterogeneous lead zirconate titanate  

NASA Astrophysics Data System (ADS)

This paper presents the work undertaken to determine the influences on the photo-induced growth of silver nanoclusters on the surfaces of lead zirconate titanate thin films. The lead zirconate titanate films were grown on indium tin oxide coated glass. They exhibited a highly textured surface and can be treated as wide bandgap semiconductors that exhibit ferroelectric behaviour. We show that there is a preferential deposition of silver metal on the ferroelectric films that is related not only to the polarization state of the ferroelectric domains but also to the surface defects such as grain boundaries and defects within the film. The greatest deposition rates are found to occur at grain boundaries where there is an approximately 40:1 ratio of silver clusters when compared to the native positive domains exhibited by the lead zirconate titanate. We propose that the mechanism for cluster growth depends on the availability, and diffusion rate, of electrons into the growing cluster and that the clusters grow from a discrete nucleation point. We also show that the growth of a monolayer of silver is sufficient to prevent the formation of electron-hole pairs by blocking the UV irradiation and that the silver nanoparticles are readily removed from the surface using an ultrasonic bath leading to a possible new method of manufacturing metal nanoparticles.

Jones, P. M.; Dunn, S.

2007-05-01

140

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

SciTech Connect

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}.

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

2000-07-01

141

Correlation between microstructure, strain behavior, and acoustic emission of soft PZT ceramics  

Microsoft Academic Search

The influence of grain size and domain configuration on the microscopic and macroscopic electromechanical properties of soft lead zirconate titanate (PZT) ceramics were studied. Fine- and coarse-grained PZT ceramics with an average grain size of 1.5 and 3.5 ?m were prepared using the conventional mixed oxide route and different sintering conditions (1225°C\\/2 h and 1300°C\\/10 h). The experiments were performed

M. J Hoffmann; M Hammer; A Endriss; D. C Lupascu

2001-01-01

142

Design and analysis of a PZT-based micromachined acoustic sensor with increased sensitivity  

Microsoft Academic Search

The ever-growing applications of lead zirconate titanate (PZT) thin films to sensing devices have given birth to a variety of microsensors. This paper presents the design arid theoretical analysis of a PZT-based micro acoustic sensor that uses interdigital electrodes (IDE) and in-plane polarization (IPP) instead of commonly used parallel plate-electrodes (PPE) and through-thickness polarization (TTP). The sensitivity of IDE-based sensors

Zheyao Wang; Chao Wang; Litian Liu

2005-01-01

143

Metal-electroceramic bonding in PZT through the selective application of laser energy  

Microsoft Academic Search

Ferrite powder has been directly bonded to the surface of poled lead zirconate titanate (PZT-4) using direct laser sintering.\\u000a The resultant cohesion between the metal and ceramic is extremely good although care must be taken with the processing in\\u000a order to limit the damage inflicted upon the PZT. Four point bending suggests that the strength of the processed samples has

Z. Amin; K. W. Dalgarno; T. P. Comyn; A. W. Tavernor

2006-01-01

144

A Sol-Gel Precursor as a Powder Binder for PZT Ceramic Fabrication  

Microsoft Academic Search

A lead zirconate titanate (PZT) precursor sol was prepared by a diol sol-gel route and used as a binder for assisting the uniaxial die pressing of PZT powders. The powders, of composition Pb(Zr0.52Ti0.48) O3, were prepared by a two step mixed oxide route using lead carbonate, zirconia and titania starting powders. The densification characteristics of the powders, which were not

S. Tangwiwat; S. J. Milne

1999-01-01

145

Fabrication of lead zirconate titanate thin films using a diffusion process of lead zirconate and lead titanate multilayer films  

Microsoft Academic Search

We consider the possibility of PZT thin-film preparation using a diffusion process of PbTiO3 (PT) and PbZrO3 (PZ) multilayer films prepared by a chemical solution deposition (CSD) method. Both PT and PZ solutions were spin-coated onto a Pt\\/Ti\\/SiO2\\/Si substrate layer-by-layer; the PT and PZ two-layer film was pyrolyzed. Subseqently, this sequence was repeated to form multilayers: PT\\/PZ ?PT\\/PZ. These multilayer

Takashi Iijima; Gang He; Hiroshi Funakubo

2002-01-01

146

??????????????????????????????????????????????????-????????????????????? MECHANICAL PROPERTIES OF LEAD ZIRCONATE TITANATE-BISMUTH LANTHANUM TITANATE COMPOSITE CERAMICS ?????? ?????, ????? ????????? ??? ??????? ???????????????  

Microsoft Academic Search

???? (1-x)PZT-xBLT ????? x ???????????? 0, 0.1, 0.3, 0.5, 0.7, 0.9 ??? 1.0 ?????????????????? ????? ????? ????? ???????????????????????????????????????????????????????????????????????????? ??????????????????????????? ?????????????????????????????????????????????? ?????????????? ?????????????????????????? ????? ???????????????????????????????????????????????? ???????? Abstract: This research studied mechanical properties of composite ceramics with formula (1-x)Pb(Zr0.52Ti0.48)O3-x(Bi3.25La0.75)Ti3O12 or (1-x)PZT-xBLT (when x = 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0 weight fraction) using a non-destructive indentation technique. The results showed

Navavan Thongmee; Anucha Watcharapasorn; Sukanda Jiansirisomboon

147

Determination of Pb/(Zr+Ti) and Zr/(Zr+Ti) Ratios of Lead Zirconate Titanate Surface by X-Ray Photoelectron Spectroscopy  

NASA Astrophysics Data System (ADS)

The quantitative analysis of the surface of lead zirconate titanate (PZT) ceramics, the compositions of which were in the ranges of 0.1PZT ceramics through separate acid and heattreatments.

Sugiyama, Osamu; Saito, Shozo; Kato, Kazuaki; Osumi, Shuzo; Kaneko, Shoji

1999-09-01

148

Electric-field-induced reorientation and flip in domain magnetization and light diffraction in an yttrium-iron-garnet/lead-zirconate-titanate bilayer  

NASA Astrophysics Data System (ADS)

A continuous reorientation and an abrupt flip to a canted structure in the magnetization of stripe domains are observed under the influence of an electric field in an yttrium-iron-garnet (YIG)/lead-zirconate-titanate (PZT) bilayer. Magneto-optic techniques have been utilized for the observation of the domain structure and the magnetization flip. It is found that electrically generated mechanical stress in PZT induces an uniaxial anisotropy field in YIG, which is large enough to initially cause a gradual change in the domain magnetization and then a transition from out-of-plane orientation to a canted state for a threshold electric field. Additional evidence for the spin flip has been obtained from data on the modulation of intensity of linearly polarized light due to diffraction by the stripe domains. A comprehensive theory for the voltage-induced magnetization flip is discussed and compared with the data. The magnetic transitions and the theory discussed here are of interests for electric-field-controlled magneto-optic and spintronic devices.

Zavislyak, I. V.; Sohatsky, V. P.; Popov, M. A.; Srinivasan, G.

2013-04-01

149

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

Microsoft Academic Search

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

Fabricio GuimarÃes Baptista; José Viterbo Filho

2009-01-01

150

Texture of poled tetragonal PZT detected by synchrotron X-ray diffraction and micromechanics analysis  

Microsoft Academic Search

The texture and lattice elastic strain due to electrical poling of tetragonal PZT (lead zirconate titanate) ceramics have been measured using high energy synchrotron X-ray diffraction. It is shown that XRD peak intensity ratios associated with crystal planes of the form {002}, {112} and {202} exhibit a linear dependence on cos?2?, where ? represents the orientation angle between the plane

D. A. Hall; A. Steuwer; B. Cherdhirunkorn; P. J. Withers; T. Mori

2005-01-01

151

Nanocomposites with increased energy density through high aspect ratio PZT nanowires  

Microsoft Academic Search

High energy storage plays an important role in the modern electric industry. Herein, we investigated the role of filler aspect ratio in nanocomposites for energy storage. Nanocomposites were synthesized using lead zirconate titanate (PZT) with two different aspect ratio (nanowires, nanorods) fillers at various volume fractions dispersed in a polyvinylidene fluoride (PVDF) matrix. The permittivity constants of composites containing nanowires

Haixiong Tang; Yirong Lin; Clark Andrews; Henry A. Sodano

2011-01-01

152

Phase and texture evolution in solution deposited lead zirconate titanate thin films: Formation and role of the Pt3Pb intermetallic phase  

NASA Astrophysics Data System (ADS)

Solution deposition is widely used for the fabrication of lead zirconate titanate (PZT) thin films on platinized silicon substrates. However, phase and texture evolution during the crystallization process is not well understood, particularly due to the difficulty in tracking changes in the thin films in situ during heating. In this work, we characterized phase and texture evolution in situ during heating and crystallization of PZT thin films using high-energy X-ray diffraction. Films were pyrolyzed at either 300 °C or 400 °C and heated at various rates between 0.5 °C/s and ~150 °C/s. For films that were pyrolyzed at 300 °C, the most rapid heating rates first induced strong intensities from a transient Pt3Pb phase. The Pt3Pb phase inherited the texture of the pre-existing platinum layer. Combined with other observations, the results suggest the conversion of the platinum to the intermetallic phase near the interface due to the interdiffusion of lead. In all experimental variations, the pyrochlore phase was observed to form concurrently with the disappearance of the Pt3Pb phase after which the perovskite phase ultimately crystallized. For films that were pyrolyzed at 400 °C, the Pt3Pb phase was not observed at any of the heating rates; instead, the pyrochlore phase was first observed, followed by the perovskite phase. Independent of the pyrolysis temperature or observation of Pt3Pb, a 111-dominant crystallographic texture formed in the perovskite phase when crystallized using fast heating rates. These results demonstrate that 111 textures in solution-derived PZT thin films are not correlated with the observation of Pt3Pb or other intermetallic or transient phases.

Nittala, Krishna; Mhin, Sungwook; Dunnigan, Katherine M.; Robinson, Douglas S.; Ihlefeld, Jon F.; Kotula, Paul G.; Brennecka, Geoff L.; Jones, Jacob L.

2013-06-01

153

Cross-poling textures in a lead zirconate titanate piezoelectric material  

SciTech Connect

Tetragonal ferroelectric materials are polarized to induce the anisotropy necessary for the piezoelectric effect. This poling of the material is inherently an orientation process. Pole figure texture measurements of poling and cross-poling in a lead zirconate titanate Navy VI material show domain motion. The resulting axisymmetric and three-dimensional textures demonstrate the contribution of 90 degree sign domain motion to piezoelectricity. Cross-poling results in strong orientations with lower applied fields than in the initial poling steps. (c) 2000 Materials Research Society.

Wan, Shan [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Bowman, Keith J. [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

2000-06-01

154

Dielectric loss peak due to platinum electrode porosity in lead zirconate titanate thin-film capacitors  

NASA Astrophysics Data System (ADS)

Impedance spectroscopy measurements were carried out in situ on lead zirconate titanate capacitors 1.2×1.2 ?m2 in size on a Samsung 4 Mbit 6 in, wafer. We show here that large dielectric loss appears at low frequencies, which is a constriction effect due to the porosity of the platinum electrode. Porous platinum electrodes facilitate an oxygen electrode reaction. The effect may be removed by annealing the platinum electrode at moderate temperature (300 °C). Such an anneal should thus be considered an essential step in the fabrication of a ferroelectric thin-film capacitor on Pt.

Jung, D. J.; Dawber, M.; Ruediger, A.; Scott, J. F.; Kim, H. H.; Kim, Kinam

2002-09-01

155

Preparation of antiferroelectric lead zirconate titanate stannate ceramics by high-energy ball milling process  

Microsoft Academic Search

Lead zirconate titanate stannate powders doped with lanthanum and niobium, namely [Pb0.99Nb0.02(Zr0.85Sn0.13Ti0.02)0.98O3, or PNZST) and (Pb0.9La0.02(Zr0.65Sn0.31Ti0.04)O3, or PLZST], were synthesized by a high-energy ball milling technique from their corresponding oxide mixtures. The milled powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and particle size analysis techniques. The sintering behaviors of the milled powders were investigated by a

L. B. Kong; J. Ma; T. S. Zhang; W. Zhu; O. K. Tan

2002-01-01

156

Compact piezoelectric micromotor with a single bulk lead zirconate titanate stator  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

157

Development of perovskite and phase transition in lead cobalt niobate modified lead zirconate titanate system  

Microsoft Academic Search

Ferroelectric lead zirconate titanate–lead cobalt niobate ceramics with the formula (1?x)Pb(Zr1\\/2Ti1\\/2)O3–xPb(Co1\\/3Nb2\\/3)O3 where x=0.0–0.5 were fabricated using a high temperature solid-state reaction method. The formation process, the structure and homogeneity of the obtained powders have been investigated by X-ray diffraction method as well as the simultaneous thermal analysis of both differential thermal analysis (DTA) and thermogravimetry analysis (TGA). It was observed

Naratip Vittayakorn; Supamas Wirunchit; Sakda Traisak; Rattikorn Yimnirun; Gobwut Rujijanagul

2008-01-01

158

Sensing region of PZT transducers bonded to concrete  

NASA Astrophysics Data System (ADS)

Despite various successful applications of Lead Zirconate Titanate (PZT) transducers in the electromechanical impedance (EMI) technique for structural health monitoring (SHM), fundamental research work on the sensitivity of the PZT transducers for damage detection is still in need. Conventionally, the root mean square deviation (RMSD) is utilized to statistically analyze the differences between the pre-damage and the post-damage electromechanical admittance signatures of a PZT transducer. Recently, another damage index method based on the structural impedance has been derived and successfully used for structural damage diagnosis. This paper presents a comparison of the sensitivity of these two methods to the damages in a concrete structure. An experimental test is carried out on a two-storey concrete frame subjected to base vibrations that simulate the earthquake and underground explosions. A number of PZT transducers are regularly arrayed and bonded to the concrete frame structure. After each phase of vibration loading, the PZT transducers are scanned to acquire the raw signatures of the PZT admittance. Subsequently, the damage indices based on both the raw signatures and the structural impedance extracted from the raw signatures are calculated. Results show that the PZT transducers with different distances away from the damage have different sensitivity to the structural damage. The relation between the damage index and the distance of the PZT transducer away from the damage is studied. Consequently, the sensitivity of the PZT transducers is discussed, and their sensing region in concrete is derived.

Hu, Yuhang; Yang, Yaowen

2007-05-01

159

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

Microsoft Academic Search

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

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

1985-01-01

160

Calculations of giant magnetoelectric effect in multiferroic composites of rare-earth-iron alloys and PZT by finite element method  

Microsoft Academic Search

Magnetoelectric effect of laminated composites of rare-earth-iron alloys (Terfenol-D) and lead–zirconate–titanate (PZT) is calculated by using finite element method. The dependences of the magnetoelectric response on the geometric configuration, the orientations of magnetostriction and polarization, and the applied magnetic field are presented for various sandwiched composites in details. The giant magnetoelectric effect predicted for the Terfenol-D\\/PZT composites is in agreement

Gang Liu; Ce-Wen Nan; Ning Cai; Yuanhua Lin

2004-01-01

161

MEMS power generator with transverse mode thin film PZT  

Microsoft Academic Search

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

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

2005-01-01

162

Kinetics of polarization reversal in irradiated thin PZT films  

Microsoft Academic Search

The effect of irradiation with electrons and neutrons and of exposure to synchrotron radiation on cyclic switching of polarization\\u000a in thin films of lead zirconate titanate Pb(Zr,Ti)O3 (PZT) was studied. It is shown that variations in the shape of switching currents are due to the generation of a spatially\\u000a nonuniform bound internal field with account for an increase in the

D. K. Kuznetsov; I. S. Baturin; V. Ya. Shur; N. Menou; C. Muller; T. Schneller; A. Sternberg

2006-01-01

163

Stress corrosion cracking of a PZT piezoelectric ceramics  

Microsoft Academic Search

Stress corrosion cracking (SCC) of a lead–zirconate–titanate (PZT) piezoelectric ceramics in water, methanol and formamide has been investigated at constant load test using a single-edge notched tensile specimen. The result showed that SCC or static fatigue fracture could occur in the three solutions, and the normalized threshold stress intensity factor of SCC was KISCC\\/KIC=0.66 (in water), 0.73 (in methanol) and

Y. Wang; W. Y. Chu; Y. J. Su; L. J. Qiao

2003-01-01

164

Device Effects of Various Zr/Ti Ratios of PZT Thin-Films Prepared by SOL-GEL Method.  

National Technical Information Service (NTIS)

PZT, PbZr sub x Tl sub 1-x 03, thin-films with various Zr/Ti ratios, 1 00/0 (lead zirconate) to 0/100 (lead titanate), were prepared by the sol-gel method. Basic electric properties, dielectric constant, tan sigma, P-E hysteresis curve, switching properti...

H. Watanabe T. Mihara C. A. Paz De Araujo

1991-01-01

165

Power harvesting using PZT ceramics embedded in orthopedic implants.  

PubMed

Battery lifetime has been the stumbling block for many power-critical or maintenance-free real-time embedded applications, such as wireless sensors and orthopedic implants. Thus a piezoelectric material that could convert human motion into electrical energy provides a very attractive solution for clinical implants. In this work, we analyze the power generation characteristics of stiff lead zirconate titanate (PZT) ceramics and the equivalent circuit through extensive experiments. Our experimental framework allows us to explore many important design considerations of such a PZT-based power generator. Overall we can achieve a PZT element volume of 0.5 x 0.5 x 1.8 cm, which is considerably smaller than the results reported so far. Finally, we outline the application of our PZT elements in a total knee replacement (TKR) implant. PMID:19812004

Chen, Hong; Liu, Ming; Jia, Chen; Wang, Zihua

2009-09-01

166

Fatigue-induced evolution of domain structure in ferroelectric lead zirconate titanate ceramics investigated by piezoresponse force microscopy  

Microsoft Academic Search

The evolution of the domain structure in lead zirconate titanate ceramics in the course of polarization fatigue is investigated by piezoresponse force microscopy. It is found that fatigue results in a strong modification of the domain structure. The domain patterns initially consisting of mainly 180° domains split into fine ferroelastic domains to relieve the mechanical stresses arising due to the

V. V. Shvartsman; A. L. Kholkin; C. Verdier; D. C. Lupascu

2005-01-01

167

The effects of the PbO content and seeding layers upon the microstructure and orientation of sol-gel derived PZT films  

Microsoft Academic Search

This paper systematically studied the factors including Pb content of precursor, PT seeding layer and TiO2 and ZrO2 seeding layers, which influence greatly the crystal orientation of lead zirconate titanate (PZT, Zr\\/Ti = 52\\/48) thin films fabricated by a sol-gel process. We find that the PZT films deposited by precursor with 20% mole excess Pb displayed strong (111) preferred orientation,

Chen Zhu; Yang Chentao; Wang Sheng; Yang Bangchao

2006-01-01

168

PVDF-PZT nanocomposite film based self-charging power cell.  

PubMed

A novel PVDF-PZT nanocomposite film has been proposed and used as a piezoseparator in self-charging power cells (SCPCs). The structure, composed of poly(vinylidene fluoride) (PVDF) and lead zirconate titanate (PZT), provides a high piezoelectric output, because PZT in this nanocomposite film can improve the piezopotential compared to the pure PVDF film. The SCPC based on this nanocomposite film can be efficiently charged up by the mechanical deformation in the absence of an external power source. The charge capacity of the PVDF-PZT nanocomposite film based SCPC in 240 s is ?0.010 ?A h, higher than that of a pure PVDF film based SCPC (?0.004 ?A h). This is the first demonstration of using PVDF-PZT nanocomposite film as a piezoseparator for SCPC, and is an important step for the practical applications of SCPC for harvesting and storing mechanical energy. PMID:24531887

Zhang, Yan; Zhang, Yujing; Xue, Xinyu; Cui, Chunxiao; He, Bin; Nie, Yuxin; Deng, Ping; Lin Wang, Zhong

2014-03-14

169

Temperature effects on the mechanical behaviour of PZT 95/5  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

170

Electric field induced phase transition of antiferroelectric lead lanthanum zirconate titanate stannate ceramics  

SciTech Connect

The electric field induced phase transition behavior of lead lanthanum zirconate titanate stannate (PLZTS) ceramics was investigated. PLZTS undergoes a tetragonal antiferroelectric (AFE{sub Tet}) to rhombohedral ferroelectric (FE{sub Rh}) phase transition with the application of an electric field. The volume increase associated with this antiferroelectric (AFE){endash}ferroelectric (FE) phase transition plays an important role with respect to actuator applications. This volume increase involves an increase in both transverse and longitudinal strains. The E field at which the transverse strain increases is accompanied by an abrupt jump in polarization. The longitudinal strain, however, lags behind this polarization jump exhibiting a slight decrease at the onset of phase switching. This decoupling was related to the preferentially oriented AFE domain configuration, with its tetragonal c-axis perpendicular to the applied electric field. It is suggested that phase switching involves multiple steps involving both structural transformation and domain reorientation. {copyright} {ital 1997 American Institute of Physics.}

Park, S.; Pan, M.; Markowski, K.; Yoshikawa, S.; Cross, L.E. [Materials Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)] [Materials Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

1997-08-01

171

Evolution of bias field and offset piezoelectric coefficient in bulk lead zirconate titanate with fatigue  

SciTech Connect

Hysteresis loops of the piezoelectric coefficient, d{sub 33}=f(E{sub 3}), are measured on virgin and fatigued lead zirconate titanate ceramics. Four parameters are directly extracted from the measurements: internal bias field E{sub b}, offset piezoelectric coefficient d{sub offset}, coercive field E{sub c}, and remnant piezoelectric coefficient d{sub r}. The reduction in d{sub r} displays the decreasing switchable polarization with fatigue cycling. E{sub b} and d{sub offset} are found to be linearly related. After thermal annealing, both offsets disappear, while the increase in E{sub c} and the reduction in d{sub r} withstand annealing. The microscopic entities responsible for the offsets are less stable than those for reduced switching.

Zhang Yong; Baturin, Ivan S.; Aulbach, Emil; Lupascu, Doru C.; Kholkin, Andrei L.; Shur, Vladimir Ya.; Roedel, Juergen [Institute of Materials Science, Darmstadt University of Technology, 64287 Darmstadt (Germany); Institute of Physics and Applied Mathematics, Ural State University, Ekaterinburg 620083 (Russian Federation); Institute of Materials Science, Darmstadt University of Technology, 64287 Darmstadt (Germany); Department of Ceramics and Glass Engineering and CICECO, University of Aveiro, 3810-193 Aveiro (Portugal); Institute of Physics and Applied Mathematics, Ural State University, Ekaterinburg 620083 (Russian Federation); Institute of Materials Science, Darmstadt University of Technology, 64287 Darmstadt (Germany)

2005-01-03

172

Dielectric properties of lead lanthanum zirconate stanate titanate antiferroelectric thin films prepared by pulsed laser deposition  

NASA Astrophysics Data System (ADS)

Lead lanthanum zirconate stanate titanate (PLZST) thin films of approximately 200 nm in thickness were deposited on Pt-buffered silicon substrates using pulsed laser deposition method. The samples were prepared under different substrate temperatures but with the same oxygen partial pressure of 0.2 mbar and laser fluence of approximately 4 J/cm2. We found that the Pb loss during the deposition process plays an important role in the formation of perovskite phase. Postdeposition annealing under different oxygen pressure, ranging from 0.2 mbar to atmospheric oxygen pressure but for the same annealing duration (15 min), was carried out in order to clarify the effects of the annealing ambient, from the viewpoint of crystallographic structure as well as electrical and dielectric properties. The physical origin is discussed.

Yao, Yingbang; Zhai, Jiwei; Chen, Haydn

2004-06-01

173

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

NASA Astrophysics Data System (ADS)

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.

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

2012-07-01

174

Preparation of a high-quality PZT thick film with performance comparable to those of bulk materials for applications in MEMS  

NASA Astrophysics Data System (ADS)

High-quality lead zirconate titanate (PZT) thick films have been prepared on silicon substrates by combining PZT-Si bonding and wet-etching technology. The bulk PZT wafer was first bonded to the silicon substrate using a 2 µm thick intermediate layer of epoxy resin with a bonding strength higher than 10 MPa. Then the bulk PZT was thinned by a wet-etching method. The thickness of the final PZT films depends on the etching time. The PZT thick films after being polished showed a surface roughness of about 20 nm (RMS), which can satisfy most of the requirements in MEMS. The prepared PZT thick films show a dielectric constant as high as 2400 below 100 kHz, remnant polarization of 13 µC cm-2, piezoelectric constant d31 of about -280 pm V-1 and Young's modulus of about 63 GPa. The measured electromechanical properties of the PZT thick films were comparable to those of the corresponding bulk ceramics. This approach makes it possible to obtain high-quality PZT films because it separates the PZT wafer fabrication from the target substrate and consequently allows integration of the PZT thick films onto many kinds of substrates. Finally, a self-sensing bulk PZT thick film actuator was fabricated as an example of a basic PZT-Si diaphragm structure that can be used in piezoelectric micropumps, and its sensing and actuating performances were also demonstrated.

Xu, Xiao-Hui; Chu, Jia-Ru

2008-06-01

175

Preparation and electrical properties of 1-3 PZT fiber/IPNs piezoelectric composites  

NASA Astrophysics Data System (ADS)

Lead zirconate titanate/IPN piezoelectric composites with 1-3 connectivity consisting in Interpenetrating Polymer Networks (IPN) matrix and Lead Zirconate Titanate (PZT) fibers with length of 50um fabricated by the sol-gel route were prepared through solution mixing method. The process of PZT gel fibers formed and the changes of crystal grain sizes during thermal treatment were traced and analyzed by TG-DTA and XRD methods. Then the composites were polarized at 100°C for 45min. The micro patterns of PZT fibers and PZT fibers/IPN composites were observed by polarizing microscopes. The electrical properties studies of 1-3 composites in function of temperatures and frequencies indicate that, the values of electrical parameters of composites detected were all smaller than that PZT and larger than that IPN matrix. Also, the polarized process and polarized mechanism of PZT fiber/IPN composites were discussed in view of dielectric constant results detected. And the detection results of electrical properties show consistency of the theoretical analysis results of composites.

Liu, J.; Tang, D. Y.; Wu, X. L.; Qiao, Y. J.

2007-10-01

176

Effect of substrate induced strains on the magnetic and ferroelectric properties of epitaxial bilayer thin films of lead zirconate titanate and cobalt ferrite  

NASA Astrophysics Data System (ADS)

Epitaxial bilayer thin films of cobalt ferrite (CFO) and lead zirconium titanate (PZT) were deposited on MgO (100) and SrTiO3 (STO) (100) substrates by pulsed laser deposition. The structural properties were characterized using X-ray diffraction and atomic force microscopy. The magnetic properties were measured at 10 K and 300 K in both parallel and perpendicular magnetic fields. The CFO-PZT bilayers showed enhanced or reduced magnetization compared to the single layer CFO films depending on the substrate of deposition. The ferroelectric properties of the CFO-PZT bilayers showed enhanced polarization compared to PZT single layer films on both types of substrates. A strain compression-relaxation mechanism was proposed in order to explain the structure-property relationships in the CFO-PZT bilayers.

Mukherjee, Devajyoti; Dhakal, Tara; Hyde, Robert; Mukherjee, Pritish; Srikanth, Hariharan; Witanachchi, Sarath

2011-03-01

177

Identification and elimination of organic contaminants on the surface of PLZT ceramic wafers. [Pb La zirconate-titanate  

Microsoft Academic Search

Surface contamination of PLZT (lead lanthanum zirconate-titanate) hot-pressed ferroelectric ceramics being used as the electrooptic wafers in thermal\\/flash protective goggles has caused ''mottling'' on the surface of the wafers adversely affecting the performance of the goggles. Mottling describes the nonuniform appearance of the goggle lens in the transmitting (open) and protective (closed) states. Experiments were devised to identify the contaminant

1978-01-01

178

Sol-gel-derived PZT fibers: development and limitations  

NASA Astrophysics Data System (ADS)

Fine scale lead zirconate titanate (PZT) fibers were fabricated from sol-gel processed viscous 'sol' using spinning methodology developed for the continuous production of glass and carbon fibers. Subsequent drying and firing at temperatures above 700 degrees Celsius resulted in phase pure perovskite fibers with diameters ranging from 30 to 70 micrometers. The dense fibers were comprised of sub-micron grains at sintering temperatures below 1000 degrees Celsius, growing to 2 - 3 micrometers at 1200 degrees Celsius. The dielectric properties of the sol-gel derived fibers were comparable with that of bulk ceramics for both undoped and modified PZT compositions. Relevant to mechanical properties, however, the fine scale PZT fibers exhibited fracture strengths on the order of 50 MPa, well below that of structural fiber materials, e.g. Al2O3, limiting their potential use in active structural composites.

Meyer, Richard J., Jr.; Yoshikawa, Shoko; Shrout, Thomas R.

1996-02-01

179

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

PubMed

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

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

2014-05-14

180

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

PubMed

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

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

2012-01-01

181

Crystal structure and electrical properties of bismuth sodium titanate zirconate ceramics  

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

182

RF magnetron sputter deposition and analysis of strontium-doped lead zirconate titanate thin films  

NASA Astrophysics Data System (ADS)

The paper investigates conditions for depositing perovskite-oriented strontium-doped lead zirconate titanate (PSZT) thin films using RF magnetron sputtering. PSZT is a material that can exhibit high piezoelectric and ferroelectric properties. The deposition was conducted using an 8/65/35 PSZT sputtering target. The effects of sputtering conditions and the deposition rates for films sputtered onto several surfaces (including gold and platinum coated substrates) were studied. Combinations of in-situ heating during sputtering and post-deposition Rapid Thermal Annealing (RTA) were performed and resulting phases determined. RTA was carried out in argon to observe their effects. The sputtered films were analyzed by Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD), and X-Ray Photoelectron Spectroscopy (XPS). Results show dramatic differences in the grain structure of the deposited films on the different surfaces. The stoichiometry of the sputtered films is demonstrated using XPS. In the case of gold and platinum coated substrates, sputtering was also carried out for different durations, to establish the growth rate of the film, and to observe the variation in grain size with sputtering duration. The deposited thin films were resistant to most chemical wet etchants and were Ion Beam Etched (IBE) at 19 nm/min.

Sriram, Sharath; Bhaskaran, Madhu; Holland, Anthony S.; Fardin, Ernest; Kandasamy, Sasikaran

2006-12-01

183

Development of silver–metal oxide reactive air braze alloys for electroding PZT ceramics  

Microsoft Academic Search

Existing multi-layer devices using lead-based piezoelectric ceramics utilize an internal electrode that does not bond the\\u000a ceramic layers. Improvements in device performance and processing could be gained if the electrode also acted as a bond between\\u000a the ceramic layers. In the current work, the feasibility of brazing lead zirconate titanate (PZT) in ambient conditions utilizing\\u000a silver-based alloys containing low melting

E. J. Pavlina; A. M. Meier; P. Monteleone; J. D. Weigner

2007-01-01

184

Effects of Microstructural Variables on the Shock Wave Response of PZT 95\\/5  

Microsoft Academic Search

The particular lead zirconate\\/titanate composition PZT 95\\/5-2Nb was identified many years ago as a promising ferroelectric ceramic for use in shock-driven pulsed power supplies. The bulk density and the corresponding porous microstructure of this material can be varied by adding different types and quantities of organic pore formers prior to bisque firing and sintering. Early studies showed that the porous

ROBERT E. SETCHELL; BRUCE A. TUTTLE; JAMES A. VOIGT

2003-01-01

185

Nonlinear constitutive behavior of soft and hard PZT: experiments and modeling  

Microsoft Academic Search

This work characterizes and models the nonlinear inelastic behavior of lead zirconate–titanate (PZT) ceramics. A detailed investigation of the hysteresis loop of the stress–strain curve shows that the process of ferroelastic non-180° polarization switching and of switching saturation are, respectively, a smooth softening process and a gradual hardening process. The inflection point in the curve is found to be a

J Fan; W. A Stoll; C. S Lynch

1999-01-01

186

Preparation and characterization of PZT solid solutions via sol–gel process  

Microsoft Academic Search

The present research describes a modified sol–gel process that has been developed for the preparation of lead zirconate titanate (PZT) (0.52\\/0.48) powders. In this route, diethanolamine (DEA) was used as a complexing agent to keep the metal ions in homogeneous solutions without undergoing precipitation. Drying treatment led to development of transparent gel network. Phase-pure perovskite structure was formed at 500°C.

Radhouane Bel Hadj Tahar; Noureddine Bel Hadj Tahar; Abdelhamid Ben Salah

2007-01-01

187

Preparation and characterization of PZT solid solutions via sol gel process  

Microsoft Academic Search

The present research describes a modified sol gel process that has been developed for the preparation of lead zirconate titanate (PZT) (0.52\\/0.48) powders. In this route, diethanolamine (DEA) was used as a complexing agent to keep the metal ions in homogeneous solutions without undergoing precipitation. Drying treatment led to development of transparent gel network. Phase-pure perovskite structure was formed at

Radhouane Bel Hadj Tahar; Noureddine Bel Hadj Tahar; Abdelhamid Ben Salah

2007-01-01

188

A piezo-mechanical characterization of PZT thick films screen-printed on alumina substrate  

Microsoft Academic Search

Thick soft and hard lead zirconate titanate (PZT) films are fabricated on alumina substrates using the screen-printing technique. The geometries of the substrates are suited to three different mechanical characterization tests devoted to the determination of the Young’s modulus of the films: a dynamic, a quasi-static and a nanoindentation test. Values of 52±8 and 20±7GPa for the Young’s modulus are,

Vincent Walter; Patrick Delobelle; Patrice Le Moal; Eric Joseph; Manuel Collet

2002-01-01

189

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

SciTech Connect

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.

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

190

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

PubMed Central

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.

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

2013-01-01

191

Impact Stress Measurement Using Piezoelectric Probes with PZT and Lithium Niobate Elements  

NASA Astrophysics Data System (ADS)

Previous gas gun experiments using low density foam flyers examined the dynamic response of Dynasen CA-1136 piezoelectric probes having lead zirconate titanate (PZT) elements for impact stresses in the range 0.07 to 0.3 GPa. Recent experiments have extended the dataset down to 0.01 GPa, compared PZT based probes with lithium niobate based probes and compared the measured stresses from manganin gauges with the stresses from the piezoelectric probes. For 0.1 g/cm3 polystyrene and 0.3 g/cm3 polyurethane foams impacting probes with APC 850 PZT elements and generating stresses around 0.1 GPa, the effective piezoelectric charge coefficient was close to three times the PZT manufacturer's value of 400 pC/N. As the impact stress was reduced the coefficient decreased towards 400 pC/N. The measured stresses from the lithium niobate probes were close to the stresses obtained from the manganin gauges.

Mears, A.; Routley, N. R.; Kendall, P. A.

2009-12-01

192

Design and simulation of PZT-based MEMS piezoelectric sensors  

NASA Astrophysics Data System (ADS)

Devices with increased sensitivities are needed for various applications including the detection of chemical and biological agents. This paper presents the design of microelectromechanical systems (MEMS) devices that incorporate lead zirconate titanate (PZT) films in order to realize highly sensitive sensors. In this work, the piezoelectric properties of the PZT are exploited to produce sensors that perform optimally for mass sensing applications. The sensor is designed to operate as a thin-film bulk acoustic resonator (TFBAR) whereas a piezoelectric is sandwiched between electrodes and senses a change in mass by measuring a change in resonance frequency. Modeling of the TFBAR sensor, using finite element analysis software COMSOL, was performed to examine optimal device design parameters and is presented in this paper. The effect of the PZT thickness on device resonance is also presented. The piezoelectric properties of the PZT is based on its crystal structure, therefore, optimization of the PZT film growth parameters is also described in this work. A detailed description of the fabrication process flow developed based on the optimization of the device design and film growth is also given. The TFBAR sensor consists of 150 nm of PZT, 150nm of silicon dioxide, silicon substrate, titanium/platinum bottom electrodes, and aluminum top electrodes. The top electrodes are segmented to increase the sensitivity of the sensor. The resonance frequency of the device is 3.2 GHz.

Baker, Doyle J.; Gonder, Casey; Williams, Frances; Bahoura, Messaoud; Myers, Oliver

2014-03-01

193

Monitoring damage propagation using PZT impedance transducers  

NASA Astrophysics Data System (ADS)

Structural health monitoring (SHM) is of great importance in preventing structural catastrophic failure which can lead to loss of life and property. Lead zirconate titanate (PZT) is one of the most effective types of piezoelectric material, and it has been widely used with the electromechanical impedance (EMI) based SHM technique. In the EMI technique, PZT transducers are surface bonded to a structure to be monitored, and, in the presence of electric fields, they interrogate the structure and record the admittance signatures. The existing EMI techniques have focused on single damage assessment. However, once damage occurs in a structure, it may propagate along a certain direction and eventually lead to failure or collapse of the structure. Therefore, effective monitoring of damage propagation is an important aspect in SHM. This paper presents a study on monitoring damage propagation in aluminium plates using the EMI technique. Experiments are carried out to study the damage propagation by drilling holes in sequence along the length and width directions of the plates. PZT admittance signatures are recorded for each damage state and compared with the signature of the pristine state. In addition, a semi-analytical EMI model is employed to predict the PZT admittance signatures and compare them with the experimental ones. Both experimental and predicted signatures are analysed qualitatively and quantitatively using a statistical method. The results demonstrate the capability of the EMI method for monitoring damage propagation.

Yang, Yaowen; Liu, Hui; Annamdas, Venu Gopal Madhav; Soh, Chee Kiong

2009-04-01

194

Lead zirconate titanate thin films on base-metal foils : an apporach for embedded high-permittivity passive components  

Microsoft Academic Search

An approach for embedding high-permittivity dielectric thin films into glass epoxy laminate packages has been developed. Lead lanthanum zirconate titanate (Pb{sub 0.85}La{sub 0.15}-(Zr{sub 0.52}Ti{sub 0.48}){sub 0.96}O, PLZT) thin films were prepared using chemical solution deposition on nickel-coated copper foils that were 50 m thick. Sputter-deposited nickel top electrodes completed the all-base-metal capacitor stack. After high-temperature nitrogen-gas crystallization anneals, the PLZT

J.-P. Maria; K. Cheek; S. K. Streiffer; S.-H. Kim; G. Dunn; A. I. Kingon

2001-01-01

195

Contribution of structural order–disorder to the room-temperature photoluminescence of lead zirconate titanate powders  

Microsoft Academic Search

Intense and broad visible photoluminescent (PL) band was observed at room temperature in structurally disordered PbZr0.53Ti0.47O3 powders. The lead zirconate titanate PbZr0.53Ti0.47O3 powders prepared by the polymeric precursor method and heat treated at different temperatures were structurally characterized at long range by means of X-ray diffraction. The PL was measured at room temperature samples heat treated at different temperatures. Experimental

Marcos Anicete-Santos; Margarete S. Silva; Emmanuelle Orhan; Marcio S. Góes; Maria A. Zaghete; Carlos O. Paiva-Santos; Paulo S. Pizani; Mario Cilense; José A. Varela; Elson Longo

2007-01-01

196

Contribution of structural order-disorder to the room-temperature photoluminescence of lead zirconate titanate powders  

Microsoft Academic Search

Intense and broad visible photoluminescent (PL) band was observed at room temperature in structurally disordered PbZr0:53Ti0:47O3 powders. The lead zirconate titanate PbZr0:53Ti0:47O3 powders prepared by the polymeric precursor method and heat treated at different temperatures were structurally characterized at long range by means of X-ray diffraction. The PL was measured at room temperature samples heat treated at different temperatures. Experimental

Marcos Anicete-Santosa; Margarete S. Silvab; Marcio S. Goesd; Maria A. Zaghetee; Carlos O. Paiva-Santosd; Paulo S. Pizanif; Mario Cilenseg; Elson Longog

197

Chemical solution deposition of ferroelectric lead lanthanum zirconate titanate films on base-metal foils.  

SciTech Connect

Development of electronic devices with better performance and smaller size requires the passive components to be embedded within a printed wire board (PWB). The 'film-on-foil' approach is the most viable method for embedding these components within a PWB. We have deposited high-permittivity ferroelectric lead lanthanum zirconate titanate (Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub 0.48}O{sub x}, PLZT 8/52/48) films on base metal foils by chemical solution deposition. These prefabricated capacitor sheets can be embedded into PWBs for power electronic applications. To eliminate the parasitic effect caused by the formation of a low-permittivity interfacial oxide, a conductive buffer layer of lanthanum nickel oxide (LNO) was applied by chemical solution deposition on nickel foil before the deposition of PLZT. With a {approx} 0.7-{micro}m-thick ferroelectric PLZT film grown on LNO-buffered nickel foil, we measured capacitance densities of 1.5 {micro}F/cm{sup 2}, breakdown field strength E{sub b} > 1.2 MV/cm, and leakage current density of 2 x 10{sup -8}A/cm{sup 2}. The dielectric relaxation current decay obeys the Curie-von Schweidler law, with exponent n = 0.85 and 0.94 for PLZT grown directly on Ni and that grown on LNO-buffered Ni foils, respectively. When compared with samples deposited directly on Ni substrate, PLZT grown on LNO buffered Ni substrates exhibit slimmer hysteresis loop and better energy storage capability. With these desirable characters, PLZT film-on-foil capacitors hold particular promise for use in high-voltage embedded passives.

Ma, B.; Kwon, D.-K.; Narayanan, M.; Balachandran, U.

2009-01-01

198

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

NASA Astrophysics Data System (ADS)

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.

Tong, Sheng

199

Directed colloidal assembly and characterization of PZT-polymer composites  

NASA Astrophysics Data System (ADS)

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.

Smay, James Earl

200

Hydrothermal deposition of heteroepitaxial lead zirconate titanate nanostructures and thin films  

Microsoft Academic Search

This paper describes the hydrothermal growth of heteroepitaxial PZT nanostructures on single-crystal, SrTiO3 substrates. Short processing times of 30min led to the nucleation and growth of sporadic, cubic nanoscale PZT islands on the surface of the substrate. In some cases, individual islands coalesced in one direction to form microwires over 1mm in length. Imperfections in the surface of the substrate

Steve Dunn; Scott Harada

2008-01-01

201

Multisensor array of mass microbalances for chemical detection based on resonant piezo-layers of screen-printed PZT  

Microsoft Academic Search

Original mass-microbalance sensors for gravimetric chemical detection are presented which are based on thickness-mode piezoelectric composite resonators made by lead zirconate titanate (PZT) films screen-printed on alumina substrate. By exploiting a cheap and affordable technology, such devices easily enable to manufacture gravimetric multisensor arrays on the same substrate. This is demonstrated by the presented four-sensor array manufactured on a 25×25

Vittorio Ferrari; Daniele Marioli; Andrea Taroni; Elisabetta Ranucci

2000-01-01

202

Theory, modeling and characterization of PZT-on-alumina resonant piezo-layers as acoustic-wave mass sensors  

Microsoft Academic Search

Lead zirconate titanate (PZT) films screen-printed on alumina substrate form composite piezoelectric resonators that can be exploited as acoustic-wave mass sensors. The paper presents a theoretical treatment of such layered resonators based on the use of the Mason’s model to derive the expression of the distributed-parameter electric impedance, followed by an approximation yielding a lumped-element equivalent circuit valid around the

Vittorio Ferrari; Daniele Marioli; Andrea Taroni

2001-01-01

203

Pb(Zr,Ti)O3 (PZT) fibers: Fabrication and measurement methods  

NASA Astrophysics Data System (ADS)

Fine scale lead zirconate titanate (PZT) and niobium substituted PZT (Nb-PZT) piezoelectric fibers were fabricated from sol-gel processed viscous 'sol' using the 'spinning' methodology developed for the continuous production of glass fibers. Subsequent drying and firing at above 750 C gave pure perovskite PZT and Nb-PZT fibers of 30 micron in average diameter. Further densification and grain growth were evident for fibers fired at 1250 C. Experimental methods for the determination of dielectric and polarization properties were developed to overcome inherent electric field difficulty relevant to fine scale fibers. The method to polarize fibers in a continuous manner was also demonstrated using 120 micron diameter extruded PZT fiber. The dielectric constant and polarization hysteresis values of the sol-gel derived fine fibers were comparable with that of bulk ceramics. Preliminary single fiber mechanical pull tests indicated that the tensile strength of 30 micron diameter PZT fibers were similar to that of bulk ceramics, being in the range of 35-55 MPa.

Yoshikawa, Shoko; Selvaraj, Ulagaraj; Moses, Paul; Witham, John; Meyer, Richard; Shrout, Thomas

1995-03-01

204

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

NASA Astrophysics Data System (ADS)

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.

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

2011-11-01

205

Synthesis of highly oriented lead zirconate-lead titanate film using metallo-organics  

SciTech Connect

This paper reports on crack-free Pb(Zr,Ti)O[sub 3] (PZT) thin films with preferred orientation that were prepared successfully on MgO (100), SrTiO[sub 3] (100), and Pt/Ti/SiO[sub 2]/Si substrates from metal alkoxide solutions. Calcination of precursor films in a H[sub 2]O[minus] O[sub 2] gas mixture was found to be effective not only for low-temperature crystallization of perovskite PZT, but also for obtaining the preferred orientation of PZT films. Single-phase PZT films with high preferred orientation were synthesized on MgO (100) and Pt/Ti/SiO[sub 2]/Si substrates at 550[degrees] and 600[degrees] C for 2 h, respectively. The PZT film on the Pt/Ti/Si-O[sub 2]/Si substrate showed a permittivity of 520, tan [delta] of 0.03, a remanent polarization of 24 [mu]C/cm[sup 2], and a coercive field of 54 kV/cm.

Hirano, S.; Yoto, T.; Kikuta, K.; Araki, Y.; Saitoh, M.; Ogasahara, S. (Dept. of Applied Chemistry, School of Engineering, Nagoya Univ., Nagoya 464 (Japan))

1992-10-01

206

From lab to industrial: PZT nanoparticles synthesis and process control for application in additive manufacturing  

NASA Astrophysics Data System (ADS)

Lead Zirconate Titanate (PZT) nanoparticles hold many promising current and future applications, such as PZT ink for 3-D printing or seeds for PZT thick films. One common method is hydrothermal growth, in which temperature, duration time, or mineralizer concentrations are optimized to produce PZT nanoparticles with desired morphology, controlled size and size distribution. A modified hydrothermal process is used to fabricate PZT nanoparticles. The novelty is to employ a high ramping rate (e.g., 20 deg C/min) to generate abrupt supersaturation so as to promote burst nucleation of PZT nanoparticles as well as a fast cooling rate (e.g., 5 deg C/min) with a controlled termination of crystal growth. As a result, PZT nanoparticles with a size distribution ranging from 200 nm to 800 nm are obtained with cubic morphology and good crystallinity. The identification of nanoparticles is confirmed through use of X-ray diffractometer (XRD). XRD patterns are used to compare sample variations in their microstructures such as lattice parameter. A cubic morphology and particle size are also examined via SEM images. The hydrothermal process is further modified with excess lead (from 20% wt. to 80% wt.) to significantly reduce amorphous phase and agglomeration of the PZT nanoparticles. With a modified process, the particle size still remains within the 200 nm to 800 nm. Also, the crystal structures (microstructure) of the samples show little variations. Finally, a semi-continuous hydrothermal manufacturing process was developed to substantially reduce the fabrication time and maintained the same high quality as the nanoparticles prepared in an earlier stage. In this semi-continuous process, a furnace is maintained at the process temperature (200 deg C), whereas autoclaves containing PZT sol are placed in and out of the furnace to control the ramp-up and cooling rates. This setup eliminates an extremely time-consuming step of cooling down the furnace, thus saving tremendous amount of process time making fabrication of a large amount of PZT nanoparticles possible.

Huang, Hsien-Lin

207

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

NASA Astrophysics Data System (ADS)

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.

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

2011-06-01

208

1.6 V nanogenerator for mechanical energy harvesting using PZT nanofibers.  

PubMed

Energy harvesting technologies that are engineered to miniature sizes, while still increasing the power delivered to wireless electronics, (1, 2) portable devices, stretchable electronics, (3) and implantable biosensors, (4, 5) are strongly desired. Piezoelectric nanowire- and nanofiber-based generators have potential uses for powering such devices through a conversion of mechanical energy into electrical energy. (6) However, the piezoelectric voltage constant of the semiconductor piezoelectric nanowires in the recently reported piezoelectric nanogenerators (7-12) is lower than that of lead zirconate titanate (PZT) nanomaterials. Here we report a piezoelectric nanogenerator based on PZT nanofibers. The PZT nanofibers, with a diameter and length of approximately 60 nm and 500 microm, were aligned on interdigitated electrodes of platinum fine wires and packaged using a soft polymer on a silicon substrate. The measured output voltage and power under periodic stress application to the soft polymer was 1.63 V and 0.03 microW, respectively. PMID:20499906

Chen, Xi; Xu, Shiyou; Yao, Nan; Shi, Yong

2010-06-01

209

Structural and electrical characterization of PZT on gold for micromachined piezoelectric membranes  

NASA Astrophysics Data System (ADS)

Piezoelectric membranes have been fabricated that incorporate a gold bottom electrode with an adhesion layer of titanium tungsten (10:90 wt. %). For solution-deposited acetic acid based lead zirconate titanate (HoAc-PZT) with a Zr:Ti ratio of 40:60, the film’s average piezoelectric coefficient, e31, is -5.31 C/m2, with a dielectric constant of 814 at 200 Hz, which is similar to values for platinum bottom electrodes. The PZT structure remains columnar on both types of bottom electrodes. Initial fabrication attempts resulted in cracking that initiated in the PZT layer of the structure. X-ray photoelectron spectroscopy was utilized to establish how processing affects diffusion throughout the composite membrane structure. Crack-free membranes were fabricated and tested. This paper discusses the performance properties and piezoelectric fatigue results for these membranes.

Robinson, M. C.; Morris, D. J.; Hayenga, P. D.; Cho, J. H.; Richards, C. D.; Richards, R. F.; Bahr, D. F.

2006-11-01

210

Ultra-thin and isolated dots in polycrystalline lead zirconate titanate films.  

PubMed

Size effects with critical thickness or minimum volume for ferroelectricity are of importance in the application of polycrystalline PZT thin films as future memory devices and as storage media. Isolated dots of perovskite phases in the matrix of pyrochlore were synthesized by isothermal annealing through transformation from amorphous to perovskite. Control of the transformation kinetics allows us to produce the isolated ferroelectric dots with a diameter of 50 nm. Domain structure of the isolated dots is also studied by piezoresponse force microscopy. As prepared, all isolated dots contain perpendicularly polarized monodomains. Domain structures and switching behaviors of the isolated dots are similar to those of the single crystalline PZT films. Polycrystalline PZT films with a thickness of 50 nm were also investigated. They show excellent piezoresponse properties and switching behaviors. Ultra-thin polycrystalline PZT films can play a major role in the application of future ferroelectric memories and field-effect transistors as well as for storage media using the local probe technique. PMID:17186915

Shin, Hyunjung; Lee, Bongki; Kim, Chanhyung; Kim, Seung-Hyun

2006-12-01

211

Grain growth kinetics and electrical properties of lanthanum modified lead zirconate titanate (9/65/35) based ferroelectric ceramics  

SciTech Connect

The influence of the microstructural characteristics on the dielectric and electrical properties has been investigated for Nd{sup 3+} doped lanthanum modified lead zirconate titanate ferroelectric ceramics, obtained by the conventional solid-state reaction method, by taking into account different sintering conditions. The grain growth mechanism has been investigated and a cubic-type grain growth law was observed for samples with grain size varying from 1.00 up to 2.35 {mu}m. The porosity and grain size dependences of the phase transition parameters, such as the maximum dielectric permittivity and its corresponding temperature ({epsilon}{sub m} and T{sub m}, respectively) were also investigated. The ac conductivity analyses followed the universal Jonscher law. The behavior of the frequency exponent (s) was analyzed through the correlated barrier hopping model. Both ac and dc conductivity results have been correlated with the observed microstructural features.

Roca, R. Alvarez; Guerrero, F. [Departamento de Fisica, Grupo de Ceramicas Ferroeletricas, UFSCar, Rod. Washington Luis, Km 235, CEP 13565-905 Sao Carlos, Sao Paulo (Brazil); Departamento de Fisica, Facultad de Ciencias Naturales, Universidad de Oriente, 90500 Santiago de Cuba (Cuba); Botero, E. R.; Garcia, D.; Eiras, J. A. [Departamento de Fisica, Grupo de Ceramicas Ferroeletricas, UFSCar, Rod. Washington Luis, Km 235, CEP 13565-905 Sao Carlos, Sao Paulo (Brazil); Guerra, J. D. S. [Grupo de Ferroeletricos e Materiais Multifuncionais, Instituto de Fisica, Universidade Federal de Uberlandia, 38400-902 Uberlandia, Minas Gerais (Brazil)

2009-01-01

212

Effects of rare earth metal substituents on the high power piezoelectric properties in lead zirconate titanate-lead (antimony,manganese)O(3) ceramics  

NASA Astrophysics Data System (ADS)

Improved piezoelectric materials with higher vibrational velocities are needed to meet the demands of advanced high power electromechanical applications. In this thesis, the effects of the rare earth (RE) metal substituents on the vibrational velocity, the piezoelectric properties and polarization behavior of Pb(Zr,Ti)O3-Pb(Sb,Mn)O3 ceramics have been investigated. Under high drive levels, the mechanical quality factor and the vibrational velocity were both significantly improved by RE substitution. For a longitudinal vibrator, driven under the d31 mode, root mean square value (rms value) of vibration velocity as high as 0.9 m/s under an electric field of 10 kV/m (rms value) has been found for Yb-substituted specimens, which is 1.5 times higher than that of base Pb(Zr,Ti)O3-Pb(Sb,Mn)O 3 ceramics. For most of rare earth substituents investigated in this system, regardless of the species ionic radii, the piezoelectric properties were observed to have combinative "hard" and "soft" characteristics. "Hard" piezoelectrics have higher Qm values, but lower k31 values. On the other hand, "soft" piezoelectrics have lower Qm values, but higher k31 values. The increased mechanical quality factor Qm (typical of "hard" piezoelectrics) and increased electromechanical coupling coefficient k31 (typical of "soft" ones) were both achieved by RE substitution. With increasing rare earth substituent ionic size, there was no absolute proportional relationship between k31/Qm and dopant ionic size observed. Polarization-electric field (P-E) measurements revealed a significant relaxational polarization similar to a "soft" piezoelectric, in addition to an internal dipolar field similar to a "hard" piezoelectric. A possible explanation for the combinative "hardening" and "softening" effects is the coexistence of randomly quenched and mobile defects. The time dependences after poling of the mechanical quality factor Q m, electromechanical coupling coefficient k31 and dielectric constant K have been investigated for both "soft" and "hard" lead zirconate titanate (PZT) ceramics. A significant increase of Qm with time was observed for "hard" PZTs, however "soft" ones did not exhibit any changes during the same time period. The aging rate after poling was found to be related to the degree of "hard" characteristics. Polarization versus electric field (P-E) measurements of "hard" PZTs revealed the development of a shift of the response along the E axis with time. It is believed that an internal dipolar field develops with time, due to a reorientation of defect dipoles along the direction of spontaneous polarization through oxygen diffusion. (Abstract shortened by UMI.)

Gao, Yongkang

213

Effect of geometry and electrical boundary conditions on R-curves for lead zirconate titanate ceramics  

Microsoft Academic Search

R-curve measurements on PZT poled in thickness direction were carried out on CT specimens under different electric boundary conditions. The effect of specimen geometry was evaluated by measuring R-curves in CT specimens of different thickness and comparing these with R-curves in bend bars. A low coercive stress is responsible for the development of a large switching zone. This switching zone

A. B. Kounga Njiwa; T. Fett; D. C. Lupascu; J. Rödel

2006-01-01

214

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

NASA Astrophysics Data System (ADS)

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.

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

2013-03-01

215

Preparation and characterization of PZT solid solutions via sol gel process  

NASA Astrophysics Data System (ADS)

The present research describes a modified sol-gel process that has been developed for the preparation of lead zirconate titanate (PZT) (0.52/0.48) powders. In this route, diethanolamine (DEA) was used as a complexing agent to keep the metal ions in homogeneous solutions without undergoing precipitation. Drying treatment led to development of transparent gel network. Phase-pure perovskite structure was formed at 500 °C. The crystallization behavior of the sol-gel-derived powders was studied by X-ray diffraction (XRD) and simultaneous thermal analysis. Differences between the sequence of phase formation encountered in the traditional (oxide-mix) synthesis and that in chemically derived lead zirconate titanate ceramics are discussed.

Bel Hadj Tahar, Radhouane; Bel Hadj Tahar, Noureddine; Ben Salah, Abdelhamid

2007-09-01

216

Improving yield of PZT piezoelectric devices on glass substrates  

NASA Astrophysics Data System (ADS)

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%.

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

217

Microfabrication of PZT force sensors for minimally invasive surgical tools  

NASA Astrophysics Data System (ADS)

Minimally invasive surgery (MIS) is the most exciting and rapidly developing area where force sensing is actually of central importance. Micromachined piezoelectric sensors can be integrated onto MIS tools for improved diagnosis and treatment monitoring. A micro-machined freestanding lead zirconate titanate (PZT) force sensor is fabricated using five masks process incorporating deep reactive ion, ion beam and wet-chemical etching techniques. The PZT sensor is designed as a parallel plate capacitor structure in which the sol-gel prepared 1-µm thick PZT film is sandwiched between top (Au/Cr) and bottom (Pt/Ti) metal electrodes mounted on a thin Si membrane. This paper also describes a new wet chemical approach for patterning PbZr0.52Ti0.48O3 films. The etch recipe provided excellent etch control, minimized undercut, preserved the photoresist mask, and effectively removed the residues on the etched surfaces. A high etch rate (200 nm/min), high selectivity with respect to photoresist, and limited under-cutting (1.5:1, lateral : thickness) were obtained. The fabricated force sensor exhibited good ferroelectric properties. The current fabrication procedure and electrical analysis can be considered as a breakthrough for fabricating freestanding PZT force sensor in any desired shape and dimensions, as well as a good example of ferroelectric microdevices.

Ezhilvalavan, S.; Zhang, Zaoli; Loh, Jeremy; Ying, Jackie Y.

2006-04-01

218

Optical Second-Harmonic Microscopy Applied to the Local Probing of the State of Polarization in Thin Films of Lead Zirconate Titanate  

Microsoft Academic Search

The state of polarization of ferroelectric thin films differing in structure is determined by optical second-harmonic microscopy. The ferroelectric is lead zirconate titanate, Pbx(Zr0.53Ti0.47)O3. The structural differences are produced by changing the fabrication conditions. In addition, the electrical properties of the same films are evaluated by conventional methods. Optical second-harmonic micrographs of the films and local optical-hysteresis loops are obtained.

E. D. Mishina; N. E. Sherstyuk; K. A. Vorotilov; E. F. Pevtsov; A. S. Sigov; T. Rasing

2001-01-01

219

Influence of crystal phase and transparent substrates on electro-optic properties of lead zirconate titanate films  

SciTech Connect

Pb(Zr{sub x}Ti{sub 1-x})O{sub 3}[x=0.52, PZT(52) near morphotropic phase boundary], tetragonal PZT(65), and rhombohedral PZT(20) thin films have been fabricated on different transparent substrates by radio frequency sputtering. The optical studies show that the band gap energies and refractive indices of the PZT thin films are crystal phase dependent. The largest electro-optic (EO) coefficient of 219.6 pm/V has been achieved by controlling the crystal phase of the PZT thin films. The linear EO coefficients of PZT(52) films on the (Pb{sub 0.86}La{sub 0.14})TiO{sub 3}-coated glass, indium tin oxides, and MgO substrates are also studied. Such study could contribute to the crystal phase and substrate dependent PZT films for electro-optic devices and multifunctional integrated circuits.

Zhu, M. M. [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Du, Z. H.; Ma, J. [Temasek Laboratories, Nanyang Technological University, Singapore 637553 (Singapore)

2010-12-01

220

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

NASA Astrophysics Data System (ADS)

High energy synchrotron XRD was employed to determine the lattice strain ?{111} and diffraction peak intensity ratio R{200} in tetragonal PZT ceramics, both in the virgin poled state and after a bipolar fatigue experiment. It was shown that the occurrence of microstructural damage during fatigue was accompanied by a reduction in the gradient of the ?{111}-cos2 ? plot, indicating a reduction in the level of residual stress due to poling. In contrast, the fraction of oriented 90° ferroelectric domains, quantified in terms of R{200}, was not affected significantly by fatigue. The change in residual stress due to fatigue is interpreted in terms of a change in the average elastic stiffness of the polycrystalline matrix due to the presence of inter-granular microcracks.

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

2013-07-01

221

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

NASA Astrophysics Data System (ADS)

Piezoelectric transducers are often used under compressive stress in smart structure and other applications and it is therefore important to know properties of these materials as a function of applied stress. We have developed an experiment that allows us to find the piezoelectric charge coefficient as a function of uniaxial stress in the poled direction . Both dynamic and static measurements were carried out and the corresponding values of the charge coefficient d33 were obtained as a function of applied stress. These coefficients differ from each other because of the different proportions of reversible and irreversible domain changes that contribute to them and each coefficient can be important in specific applications. Results on a range of PZT ceramics manufactured by EDO Corporation are presented; in general, they show a non- linear behavior with an initial increase in d33 as the stress increases followed by a significant decrease. The time dependence of the measurement has also been investigated.

Yang, G.; Liu, S. F.; Ren, W.; Mukherjee, Binu K.

2000-06-01

222

Dielectric functions and electronic band structure of lead zirconate titanate thin films  

Microsoft Academic Search

We measure pseudodielectric functions in the visible-deep ultraviolet spectral range of Pb(ZrxTi1-x)O3 (x=0.2,0.56,0.82) (PZT), Pb0.98Nb0.04(Zr0.2Ti0.8)0.96O3, Pb0.91La0.09(Zr0.65Ti0.35)0.98O3, and Pb0.85La0.15Ti0.96O3 films grown on platinized silicon substrates using a sol-gel method and on (0001) sapphire using a radio-frequency sputtering method. Using a parametric optical constant model, we estimate the dielectric functions (?) of the perovskite oxide thin films. Taking the second derivative of

Hosun Lee; Youn Seon Kang; Sang-Jun Cho; Bo Xiao; Hadis Morkoç; Tae Dong Kang; Ghil Soo Lee; Jingbo Li; Su-Huai Wei; P. G. Snyder; J. T. Evans

2005-01-01

223

Visable-Deep UV Dielectric Functions and Electronic Band Structure of Lead Zirconate Titanate Thin Films  

Microsoft Academic Search

We measure pseudodielectric functions in the visible-deep ultraviolet spectral range of Pb(ZrxTi1-x)O3 (x=0.2, 0.56, 0.82) (PZT), Pb0.98Nb0.04(Zr0.2Ti0.8)0.96O3,Pb0.91La0.09(Zr0.65Ti0.35)0.98O3, andPb0.85La0.15Ti0.96O3 films. Using a parametric optical constant model, we estimate the dielectric functions (?) of the perovskite oxide thin films. Taking the second derivative of the fitted layer dielectric functions and using the standard critical point model, we determine the parameters of the

Hosun Lee; T. D. Kang; Y. S. Kang; S.-J. Cho; H. Morkoc; J. Li; S.-H. Wei; P. G. Snyder

2006-01-01

224

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

SciTech Connect

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

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

2013-07-14

225

Preparation and Characterization of PZT Wafers  

NASA Astrophysics Data System (ADS)

Piezoelectric materials have recently attracted a lot of attention for ultrasonic structural health monitoring (shm) in aerospace, defence and civilian sectors, where they can act as both actuators and sensors. Incidentally, piezoelectric materials in the form of wafers (pwas-piezoelectric wafer active sensor, approx. 5-10 mm square and 0.2-0.3 mm thickness) are inexpensive, non intrusive and non-resonant wide band devices that can be surface-mounted on existing structures, inserted between the layers of lap joints or embedded inside composite materials. The material of choice for piezoelectric wafers is lead zirconate titanate (PZT) of composition close to morphotropic phase boundary [pb(zr0.52 ti0.48)o3]. However, an excess pbo is normally added to pzt as a densification aid and also to make up for the lead loss during high temperature sintering. Hence, it is of paramount importance to know how the shift of the lead content from the morphotropic composition affects the piezoelectric and mechanical properties of the sintered wafers, keeping in view the importance of mechanical properties of wafers in shm. In the present study, we observed that with the increase in the lead content of the sintered wafers, the dielectric and piezoelectric constants decreased. However, the elastic modulus, hardness and fracture toughness of the wafers increased with increasing lead content in the composition. Hence, the lead content in the sintered wafers should be optimized to get acceptable piezoelectric and mechanical

Seal, A.; Rao, B. S. S. Chandra; Kamath, S. V.; Sen, A.; Maiti, H. S.

2008-07-01

226

Nanocomposites with increased energy density through high aspect ratio PZT nanowires  

NASA Astrophysics Data System (ADS)

High energy storage plays an important role in the modern electric industry. Herein, we investigated the role of filler aspect ratio in nanocomposites for energy storage. Nanocomposites were synthesized using lead zirconate titanate (PZT) with two different aspect ratio (nanowires, nanorods) fillers at various volume fractions dispersed in a polyvinylidene fluoride (PVDF) matrix. The permittivity constants of composites containing nanowires (NWs) were higher than those with nanorods (NRs) at the same inclusion volume fraction. It was also indicated that the high frequency loss tangent of samples with PZT nanowires was smaller than for those with nanorods, demonstrating the high electrical energy storage efficiency of the PZT NW nanocomposite. The high aspect ratio PZT NWs showed a 77.8% increase in energy density over the lower aspect ratio PZT NRs, under an electric field of 15 kV mm - 1 and 50% volume fraction. The breakdown strength was found to decrease with the increasing volume fraction of PZT NWs, but to only change slightly from a volume fraction of around 20%-50%. The maximum calculated energy density of nanocomposites is as high as 1.158 J cm - 3 at 50% PZT NWs in PVDF. Since the breakdown strength is lower compared to a PVDF copolymer such as poly(vinylidene fluoride-tertrifluoroethylene-terchlorotrifluoroethylene) P(VDF-TreEE-CTFE) and poly(vinylidene fluoride-co-hexafluoropropylene) P(VDF-HFP), the energy density of the nanocomposite could be significantly increased through the use of PZT NWs and a polymer with greater breakdown strength. These results indicate that higher aspect ratio fillers show promising potential to improve the energy density of nanocomposites, leading to the development of advanced capacitors with high energy density.

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

2011-01-01

227

Measurement of high piezoelectric response of strontium-doped lead zirconate titanate thin films using a nanoindenter  

NASA Astrophysics Data System (ADS)

Strontium-doped lead zirconate titanate (PSZT) is reported to have a high piezoelectric coefficient (d33) in the range of 200-600 pm/V, when in the form of ceramic disks or pellets. This article reports piezoelectric response results for PSZT thin films deposited by rf magnetron sputtering on gold-coated silicon substrates. The compositions of the deposited thin films have been found to be uniform with depth, using secondary ion mass spectroscopy. The surfaces of the deposited thin films have been studied using an atomic force microscope and observed to be regular and nanostructured in nature. The piezoelectric response of the thin films, using the inverse piezoelectric effect, has been measured using a nanoindenter. Values of thin film d33 up to 608 pm/V were obtained, which is much higher than previously reported values of d33 for any thin film. The high values can be attributed to optimized deposition conditions and the low stress measured for the thin film arrangement on the substrate. The technique has been verified by obtaining a null response for silicon dioxide and by measuring d33 values of similar magnitude for PSZT thin films using an atomic force microscope in the same testing arrangement. The piezoelectric response has been mapped to study variations across the thin film and with distance from the top electrode.

Sriram, S.; Bhaskaran, M.; Holland, A. S.; Short, K. T.; Latella, B. A.

2007-05-01

228

The kinetics of the local compositional changes at the ferroelectric antiferroelectric interphase boundaries in lead lanthanum titanate zirconate solid solutions  

NASA Astrophysics Data System (ADS)

The process of local decomposition of lead-lanthanum zirconate-titanate solid solution in the vicinity of the interphase boundaries separating domains of coexisting ferroelectric and antiferroelectric phases has been investigated. The kinetics of the local decomposition of the solid solution containing 6 at.% La, 73 at.% Zr, and 27 at.% Ti in the process of ageing of samples quenched down to room temperature from the paraelectric phase is studied. The mechanisms that define the kinetics of the process of attainment of the equilibrium state of coexisting domains of ferroelectric and antiferroelectric phases are analysed. It is demonstrated that there are two main mechanisms determining the kinetics of establishing of the equilibrium inhomogeneous chemical composition of a solid solution. The slower mechanism is determined by the diffusion of the oxygen vacancies, the nonequilibrium concentration of which was created during the annealing at the temperatures above the Curie temperature. The faster process is determined by the cation diffusion caused by the local mechanical stresses in the vicinity of the interphase boundaries. The equilibrium structure establishes during a time interval of not less than 120 h.

Ishchuk, V. M.; Samoylenko, Z. A.; Sobolev, V. L.

2006-12-01

229

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

NASA Astrophysics Data System (ADS)

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 ?E indicate a strong ME coupling in the low-frequency range and a giant ME effect due to EMR at 200-300kHz for radial modes and at ˜2.7MHz for thickness modes. Data were obtained for the bias field H dependence of two key parameters, the EMR frequency fr and the ME coefficient ?E,R at resonance. With increasing H , an increase in fr and a rapid rise and fall in ?E,R are measured. In our model we consider two mechanisms for the magnetic field influence on ME interactions: (i) a shift in the EMR frequency due to changes in compliance coefficients ( ?E effect) and (ii) variation in the piezomagnetic coefficient that manifests as a change in ?E,R . Theoretical profiles of ?E vs frequency and estimates of frequency shift based on the ?E effect are in excellent agreement with the data.

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

2005-05-01

230

Nonlinear optical properties of lanthanum-modified lead zirconate titanate investigated by the femtosecond Z-scan technique  

NASA Astrophysics Data System (ADS)

We used a closed-aperture Z-scan technique to study the nonlinear optical refractive index of lanthanum-modified lead zirconate titanate (PLZT) (9/65/35) ceramics. Our laser light source was a mode-locked titanium-sapphire laser, the output pulse width was approximately 100 femtoseconds at a wavelength of 790 nm, and the repetition rate was 10 kHz. We found that PLZT had a large, positive nonlinear optical refractive index, n2 = +(3.1 +/- 0.6) × 10-8 esu, and its third-order susceptibility was calculated to be ?(3) = (9 +/- 1.8) × 10-9 esu. When an electric field (E) was applied to the PLZT, n2 increased along in direct proportion to E2. We speculate that the increase in n2 was caused by the more ordered structural arrangement of the PLZT imposed by the applied electric field. The results show that PLZT has potential applications in fast, electric-field-controlled nonlinear optical elements.

Tsai, Tsong-Ru; Yu, Chih-Hsiung

2011-12-01

231

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

PubMed

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

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

2010-01-01

232

Local damage detection for steel rebar by impedance measurements of PZT sensors  

NASA Astrophysics Data System (ADS)

Steel rebar is the most employed reinforcements in concrete structures and is subjected to damage due to environmental factors. Therefore it is meaningful to develop suitable non-destructive damage detection methods for steel rebar in engineering structures. Lead Zirconate Titanate (PZT) is one of the most effective types of piezoelectric material, and it has been widely used both sensors and transducers for the structural health monitoring (SHM) of engineering structures. Based on the coupling effect of PZT patches surface-bonded on a structural member, the electromechanical impedance (EMI) based structural damage detection has been employed to detect local damage of civil engineering structures. This paper presents the results of the experimental study on the EMI based damage detection for steel rebar specimens under different damage scenarios by analyzing the changes in the piezoelectric admittance spectrum of PZT patches surface-bonded on the steel rebar specimens. A damage index called the root mean square deviation of admittance (RMSDD) is employed to evaluate the extent of damage of the steel beam. Based on the analysis on the relationship between the damage index and the distance of the PZT sensor from the damage, the sensitivity of the PZT sensors and their sensing region is discussed. The results shows that the location and level of the damages could be quantitatively identified by converting the admittance measurements into the scalar damage index.

Kuang, Juan; Xu, Bin

2011-11-01

233

Effect of external vibration on PZT impedance signature of plate structure  

NASA Astrophysics Data System (ADS)

Electromechanical impedance (EMI) technique using lead zirconate titanate (PZT) transducers has been increasingly applied to structural health monitoring (SHM) of aerospace, civil and mechanical structures. The PZT transducers are usually surface bonded to or embedded in a structure and subjected to actuation so as to interrogate the structure at the desired frequency range. The interrogation results in the electromechanical admittance (inverse of EMI) signatures which can be used to estimate the structural health or integrity according to the changes of the signatures. In the existing EMI method, the vibration of the structure caused by the external excitations has been considered only for one dimensional scenario. This paper develops a two dimensional EMI model to account for the effect of external excitation on the PZT admittance signature. An application is illustrated with modeling of a simply supported Kirchoff plate interrogated by a single surface-bonded PZT transducer. Numerical simulation is also carried out to verify the theoretical model. Finally, the effect of external excitation on PZT impedance signature is discussed.

Yang, Yaowen; Miao, Aiwei

2008-12-01

234

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

NASA Astrophysics Data System (ADS)

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.

Chen, Mengqi; Xu, Bin

2011-11-01

235

Two-dimensional modeling of the effects of external vibration on the PZT impedance signature  

NASA Astrophysics Data System (ADS)

The electromechanical impedance (EMI) technique using piezoelectric ceramic lead zirconate titanate (PZT) transducers has been increasingly applied to structural health monitoring (SHM) of aerospace, civil and mechanical structures. The PZT transducers are usually surface bonded to or embedded in a structure and subjected to actuation so as to interrogate the structure at the desired frequency range. The interrogation results in electromechanical admittance (inverse of EMI) signatures which can be used to estimate the structural health or integrity according to the changes of the signatures. In the existing EMI method, the vibration of the structure caused by the external excitations has been considered only for the one-dimensional scenario. This paper develops a two-dimensional EMI model to account for the effect of external excitation on the PZT admittance signature. An application is illustrated with modeling of a cantilevered Kirchhoff plate interrogated by a single surface-bonded PZT transducer. Experiments and numerical simulations are also carried out to verify the theoretical model. Finally, the effects of external excitation on PZT impedance signatures are discussed.

Yang, Yaowen; Miao, Aiwei

2010-06-01

236

Application of reusable PZT sensors for monitoring initial hydration of concrete  

NASA Astrophysics Data System (ADS)

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.

Sabet Divsholi, Bahador; Yang, Yaowen

2009-03-01

237

The Effects of TI/PT Bottom Electrode on Crystallographic and Surface Characteristics of PZT Thick Films  

NASA Astrophysics Data System (ADS)

The ceramic lead zirconate titanate (PZT) films near the morphotropic phase boundary are successfully integrated into MEMS devices, especially for applications in microsensors and actuators. The ferro/piezo electric properties of PZT thick films are widely dependent on its surface quality and crystallographic orientation growth. This paper indicates the influences of platinum bottom electrode on the surface and crystallographic properties of PZT. Ti (10nm) and Pt (100nm) thin films have been deposited on silicon substrate by thermal evaporation and electron beam respectively without vacuum breaking. After annealing treatment, the Pt film exhibited (111) preferred orientation. Finally one micron thick PZT (54/46) film was deposited by a RF magnetron sputtering at room temperature in pure Argon followed by a conventional post annealing treatment on silicon substrate. The XRD measurements have shown the provskite structure of PZT films with (100) preferred orientation at annealing temperatures above 600°C and (111) preferred orientation above 650°c. The SEM results demonstrate that whatever the annealing temperature is increased, recrystallization grains and black holes on Pt surface occurs and cause morphological change of PZT surface. The AFM test shows the strong RMS roughness of platinum surface after annealing temperature at 650°C.

Koochekzadeh, Ali; Keshavarz Alamdari, Eskandar; Barzegar, Abdolghafar

238

Monitoring damage propagation using PZT impedance transducers  

NASA Astrophysics Data System (ADS)

Lead Zirconate Titanate (PZT) transducers have been extensively used in the electromechanical impedance (EMI) based structural health monitoring (SHM). Many EMI models have been developed for damage assessment, mostly focusing on single damage identification. However, in real life, structures are frequently subjected to multiple or progressive damages. Specifically, structural components such as beams and columns are subjected to loading, vibration, wear and tear which could cause multiple damages. Once damages occur, they usually propagate along certain directions due to continuous usage or inadequate protection. Moreover the increase in severity of damages may lead to failure of the structural components or even the whole structure. The EMI technique which is based on the electromechanical interaction between the PZT transducer and its host structure has been found to be effective in damage detection. However, systematic study on monitoring the progressive of damage in multiple directions in the structures is still in need. In this paper, the EMI technique using surface bonded PZT transducers is employed to obtain the structural health signature. Experimental tests are carried out to study the damage propagation on aluminum plates, where damages are created along the length and width directions of the plates by drilling holes in sequence. Structural health signatures are obtained for each damage state and compared with the signature of non-damage state, followed by the discussion on the characteristics of damage propagation. In addition, for different damaged states, finite element modeling is carried out to verify the experimental signatures. The acquired numerical results are analyzed both qualitatively and quantitatively. Both experimental and numerical results demonstrate the capability of EMI technique for damage propagation monitoring.

Yang, Yaowen; Liu, Hui; Annamdas, Venu Gopal Madhav

2008-04-01

239

Piezoelectric Properties of PZT Films Prepared by Hydrothermal Method  

NASA Astrophysics Data System (ADS)

Lead zirconate titanate (PZT) thin films of 5 ?m thick were produced by a hydrothermal method on pure titanium substrates. ZrOCl2-8H2O, Pb(NO3)2 and TiO2 were used as precursors and KOH as a promoter. The hydrothermal synthesis of PZT includes nucleation and crystal growth processes at 120°C or 140°C. The crystallization states were investigated by using scanning electron microscopy and X-Ray diffraction. Piezoelectric properties were evaluated from unimorph cantilever type actuators made of the films. The relationships between the deflection of the actuator due to piezoelectric transverse effect and applied electric field in the direction of thickness of the films showed good linearity. The output voltage from the films under cyclic compressive loading increased with increasing loading frequency, and is saturated at 10 Hz. The PZT films produced by the present methods are satisfactory as a smart material, and are better than the films produced using TiCl4 as Ti precursor.

Fujiwara, Nobuyoshi; Kusukawa, Kazuhiro; Abdul Razak, Khairunisak; Gao, Wei

240

Fabrication and characterization of laterally-driven piezoelectric bimorph MEMS actuator with sol-gel-based high-aspect-ratio PZT structure  

NASA Astrophysics Data System (ADS)

This paper reports on the fabrication and characterization of a novel laterally-driven piezoelectric bimorph micro electro mechanical systems actuator with high aspect-ratio (AR) lead-zirconate-titanate (PZT) structures. The PZT structures (AR=8) sandwiched with Pt sidewall electrodes were fabricated by a nanocomposite sol-gel process with micromachined silicon templates. A single-cantilever-type lateral bimorph actuator was successfully fabricated, and no initial vertical bending was observed, even on a 500 µm long actuator. A lateral displacement of 10 µm was obtained in bimorph actuation at driving voltages of +25 V/-5 V. Then the piezoelectric property of the PZT structure was characterized from the actuator's performance. The lateral piezoelectric actuator has a variety of potential applications as a replacement for electrostatic comb drive actuators occupying a large area.

Yoshida, Shinya; Wang, Nan; Kumano, Masafumi; Kawai, Yusuke; Tanaka, Shuji; Esashi, Masayoshi

2013-06-01

241

Effects of acetylacetone additions on PZT thin film processing  

SciTech Connect

Sol-gel processing methods are frequently used for the fabrication of lead zirconate titanate (PZT) thin films for many electronic applications. Our standard approach for film fabrication utilizes lead acetate and acetic acid modified metal alkoxides of zirconium and titanium in the preparation of our precursor solutions. This report highlights some of our recent results on the effects of the addition of a second chelating ligand, acetylacetone, to this process. The authors discuss the changes in film drying behavior, densification and ceramic microstructure which accompany acetylacetone additions to the precursor solution and relate the observed variations in processing behavior to differences in chemical precursor structure induced by the acetylacetone ligand. Improvements in thin film microstructure, ferroelectric and optical properties are observed when acetylacetone is added to the precursor solution.

Schwartz, R.W.; Assink, R.A.; Dimos, D.; Sinclair, M.B.; Boyle, T.J.; Buchheit, C.D.

1995-02-01

242

Ion beam etching of lead-zirconate-titanate thin films: Correlation between etching parameters and electrical properties evolution  

Microsoft Academic Search

Ion beam etching of sputtered Pb(Zrx,Ti1-x)O3 (PZT) with x equal to 0.54 thin films grown on Pt\\/Ti\\/SiO2\\/Si substrates has been performed using pure Ar gas. The etch rate dependence on the process parameters (current density, acceleration voltage, gas pressure) has been investigated. The PZT etch rate can reach 600 Å\\/min with acceleration voltage of 1000 V and current density of

C. Soyer; E. Cattan; D. Rèmiens; M. Guilloux-Viry

2002-01-01

243

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

NASA Astrophysics Data System (ADS)

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.

Zhong, Jian

244

Application of PZT sensors for detection of damage severity and location in concrete  

NASA Astrophysics Data System (ADS)

Piezoelectric ceramic lead zirconate titanate (PZT) based electromechanical impedance (EMI) technique has been applied for structural health monitoring (SHM) of various engineering systems. However, study on identification of damage severity and location is still in need. In the EMI method, the PZT electromechanical (EM) admittance is used as a damage indicator. Statistical techniques such as root mean square deviation (RMSD) have been employed to associate the damage level with the changes in the EM admittance signature. To achieve high sensitivity to damage, high frequency signatures (>200 kHz) have been used to monitor the region close to the PZT location. It has been reported that the use of RMSD as the damage indicator is difficult to specify the damage location and severity due to the inconsistency in the RMSD results. This paper proposes the use of large frequency (30-400 kHz) range and the RMSD values of sub-frequency intervals to eliminate the inconsistency in the results. An experiment is carried out on a real size concrete structure subjected to artificial damages. The PZT admittance signatures in a frequency range of 30 to 400 kHz for various structural damages have been recorded and the RMSD values of sub-frequency intervals of 10 kHz are calculated. Results show less inconsistency and uncertainties compared to the traditional method using limited high frequency range. It is observed that the damage close to the PZT changes the RMSD at high frequency range significantly; however the damage far away from the PZT changes the RMSD at low frequency range significantly.

Sabet Divsholi, Bahador; Yang, Yaowen

2008-12-01

245

Dielectric and ferroelectric characteristics of 0.7PZT 0.3PZN ceramics substituted with Sr  

NASA Astrophysics Data System (ADS)

Lead zirconate titanate-lead zinc niobate (PZT-PZN) ceramics with compositions close to the morphotropic phase boundary were investigated as a function of Sr doping. The powders were prepared using the columbite-(wolframite) precursor method. Dielectric and ferroelectric properties of the as-sintered and annealed samples were measured. The results showed that with increasing Sr concentration dielectric constant versus temperature curves become gradually broader. Sr doping has been shown to produce a linear reduction in the transition temperature (Tm) (294.1-12.7x °C) with concentration (x). The maximum value of the dielectric constant decreased and the degree of diffuse phase transition was enhanced with Sr doping. However, the results indicated that the degree of disorder in Sr-modified PZT-PZN was further improved by thermal annealing. After thermal annealing at 900°C for 48 h a strong enhancement of dielectric constant (?r) and remanent polarization (Pr) was observed.

Vittayakorn, Naratip; Uttiya, Sureeporn; Rujijanagul, Gobwute; Cann, David P.

2005-08-01

246

Titan  

NASA Technical Reports Server (NTRS)

With a launch in December 2001, Space Infrared Telescope Facility (SIRTF) can observe Titan in the interval after Infrared Space Observatory (ISO) but before the onset of observations by Cassini. By virtue of its broad spectral coverage in the thermal infrared, 10-180 micron, its moderately high spectral resolution, approaching lambda/delta lambda=600 over part of this wavelength range, and the very high sensitivity of its helium- cooled detectors, the Infrared Spectrometer (IRS) and MIPS on SIRTF can address several issues raised through earlier observations by the Voyager IRIS experiment and by ISO. These include, for example, a better characterization of the vertical distribution of water in Titan's middle and upper atmospheres and the discovery of new compounds, such as allene or proprionitrile. This talk will address the temperature- and composition-sounding capabilities of SIRTF, particularly in the context of how they will complement Cassini observations and aid in their planning.

Flasar, F. M.

1999-01-01

247

PZT Thin-Film Micro Probe Device with Dual Top Electrodes  

NASA Astrophysics Data System (ADS)

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

Luo, Chuan

248

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

SciTech Connect

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

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

2013-01-28

249

Synthesis, fabrication, and characterization of self-exciting, self-sensing PZT/silicon dioxide piezoelectric micro-cantilever sensors  

NASA Astrophysics Data System (ADS)

A piezoelectric cantilever (PEC) consists of a piezoelectric layer, e.g., lead-zirconate titanate (PZT) bonded to a non-piezoelectric layer, e.g., silica. Compared to other current biosensing technologies, PEC's ability to withstand damping in water and its all-electric, self-exciting, self-sensing features make it stand out for in-liquid biosensing applications that is in-situ, real-time, multiplexed, and high throughput. The scaling analysis of PECs shows that reducing a PEC's dimension can increase its mass sensitivity dramatically. The goal of the thesis study is to fabricate miniaturized piezoelectric micro-cantilever sensors (PEMS) with femtograrn mass detection sensitivity (10-15 gram/Hz) for biological and chemical sensing applications. To achieve the goal, the thesis study encompasses three major components: (1) fundamental studies on the sensor physics to allow an optimal sensor design, (2) lead zirconate titanate (PZT) sol-gel thin film development, (3) microfabrication of the PZT PEMS. For the fundamental study, the effects of the sensor's geometry on its detection sensitivity were examined both theoretically and experimentally to show that a proper nonpiezoelectric extension enhances a PEMS detection sensitivity. Using a unique sol-gel method using ethylene glycol as the solvent, dense, smooth, and defect-free PZT thin films were obtained with superb dielectric and ferroelectric properties, an intrinsic dielectric constant epsilon int= 2100 and a saturation polarization Ps=55 muC/cm 2. Integrating with silicon based micro-fabrication technologies, PZT/SiO2 PEMS 300 to 40 (m long were successfully fabricated exhibiting resonance peaks with high quality factors ranging from 120 to 320. Mass detection sensitivities of 6.7 x 10-16 g/Hz and 9.1 x 10 -16 g/Hz (mass of a single virus or a fraction of a single cell) were obtained with 40 (m and 60 (m PZT/SiO2 PEMS, respectively, in humidity detection---the smallest and most sensitive PZT based PEMS ever reported.

Shen, Zuyan

250

Miniature cryogenic valves for a Titan Lake sampling system  

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

251

Preparation and Characterization of Lead Zirconate Titanate Heterolayered Thin Films on Pt/Ti/SiO2/Si Substrate by Sol Gel Method  

NASA Astrophysics Data System (ADS)

Ferroelectric Pb(ZrxTi1-x)O3 (PZT; x=0.2, 0.8) heterolayered thin films were fabricated by the spin-coating method on the Pt electrode alternately using PZT(20/80) and PZT(80/20) metal alkoxide solutions. All PZT heterolayered films show dense structure without the presence of the rosette structure. The lower PZT layers provide the nucleation site for the formation of a perovskite phase in the upper PZT films. Pb-deficient pyrochlore phase was formed at PZT/Pt interface due to diffusion of the Pb element into the Pt bottom electrode. The relative dielectric constant and dielectric loss of the six coated PZT heterolayered film were approximately 1385 and 3.3% at 1 kHz, respectively.

Lee, Sung-Gap; Shim, Kwang-Taek; Lee, Young-Hie

1999-01-01

252

Optimizing a spectral element for modeling PZT-induced Lamb wave propagation in thin plates  

NASA Astrophysics Data System (ADS)

Use of surface-mounted piezoelectric actuators to generate acoustic ultrasound has been demonstrated to be a key component of built-in nondestructive detection evaluation (NDE) techniques, which can automatically inspect and interrogate damage in hard-to-access areas in real time without disassembly of the structural parts. However, piezoelectric actuators create complex waves, which propagate through the structure. Having the capability to model piezoelectric actuator-induced wave propagation and understanding its physics are essential to developing advanced algorithms for the built-in NDE techniques. Therefore, the objective of this investigation was to develop an efficient hybrid spectral element for modeling piezoelectric actuator-induced high-frequency wave propagation in thin plates. With the hybrid element we take advantage of both a high-order spectral element in the in-plane direction and a linear finite element in the thickness direction in order to efficiently analyze Lamb wave propagation in thin plates. The hybrid spectral element out-performs other elements in terms of leading to significantly faster computation and smaller memory requirements. Use of the hybrid spectral element is proven to be an efficient technique for modeling PZT-induced (PZT: lead zirconate titanate) wave propagation in thin plates. The element enables fundamental understanding of PZT-induced wave propagation.

Ha, Sungwon; Chang, Fu-Kuo

2010-01-01

253

Impact Stress Measurement Using Piezoelectric Probes with PZT and LN Elements  

NASA Astrophysics Data System (ADS)

Previous gas gun experiments using low density foam flyers examined the dynamic response of Dynasen CA-1136 piezoelectric probes having lead zirconate titanate (PZT) elements for stresses in the range 0.07 to 0.3 GPa. Recent experiments have extended the dataset down to 0.01 GPa, compared PZT based probes with lithium niobate (LN) based probes and compared the measured stress from manganin gauges with the stress from the piezoelectric probes. For 0.1 g/cc polystyrene foam impacting probes with APC 850 PZT elements and generating stresses between 0.1 and 0.2 GPa, the effective piezoelectric charge coefficient was 3 to 4 times the quoted value of 400 pC/N. The coefficient decreased to around 1 to 1.5 times the quoted value as the impact stress was reduced to 0.01 GPa. Differences were observed between 0.3 g/cc polyurethane and 0.1 g/cc polystyrene foams suggesting that the probe response is dependent on both the stress and the material properties of the impactor. The measured stresses from the LN probes were significantly closer to the stresses obtained from the manganin gauges.

Mears, Alan; Routley, Nathan; Kendall, Paul

2009-06-01

254

Ferroelectric behaviour of PZT thin films with secondary TiO2 phase induced defects  

NASA Astrophysics Data System (ADS)

The dielectric properties and ferroelectric phase transition in tetragonal lead zirconate titanate (PZT) thin films containing titanium oxide (TiO2) as a secondary phase have been studied. TiO2 phase inclusion is observed in PZT films prepared by the electron beam evaporation of multicomponent oxides as the result of the dissociation of the pyrochlore PbTi3O7 phase on high-temperature annealing. TiO2 phase inclusion results in the asymmetry of the dielectric hysteresis along the polarization axis. Micro polar regions due to defects caused by TiO2 are responsible for the latter. These regions become randomized due to thermal energy and, as a result, the dielectric hysteresis becomes symmetrical. Investigation of the complex permittivity reveals that the relaxation time decreases with an increase of temperature and, as a result, non-Debye-like behaviour at low temperature gives way to Debye-like behaviour suggesting that the material comprises a large number of relaxing regions. Measurement of the dielectric constant revealed that the ferroelectric-paraelectric phase transition is diffused and shifts to the high-temperature side with a measurement frequency characteristic of the relaxor-like behaviour. This transition follows the quadratic (T-T0)2 law instead of the Curie-Weiss law for normal PZT films. A value of 48 °C was obtained for the diffuseness of the phase transition.

Darvish, S. R.; Rastogi, A. C.

2000-09-01

255

Effects of high energy x ray and proton irradiation on lead zirconate titanate thin films' dielectric and piezoelectric response  

SciTech Connect

The effects of irradiation by X rays and protons on the dielectric and piezoelectric response of highly (100)-textured polycrystalline Pb(Zr{sub x}Ti{sub 1-x})O{sub 3} (PZT) thin films have been studied. Low-field dielectric permittivity, remanent polarization, and piezoelectric d{sub 33,f} response all degraded with exposure to radiation, for doses higher than 300 krad. At first approximation, the degradation increased at higher radiation doses, and was stronger in samples exposed to X rays, compared to the proton-irradiated ones. Nonlinear and high-field dielectric characterization suggest a radiation-induced reduction of the extrinsic contributions to the response, attributed to increased pinning of the domain walls by the radiation-induced point defects.

Bastani, Y.; Cortes-Pena, A. Y.; Wilson, A. D. [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)] [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Gerardin, S.; Bagatin, M.; Paccagnella, A. [DEI-Department of Information Engineering, University of Padova, Padova 35131 (Italy)] [DEI-Department of Information Engineering, University of Padova, Padova 35131 (Italy); Bassiri-Gharb, N. [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States) [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2013-05-13

256

Adjustable grazing incidence x-ray optics based on thin PZT films  

NASA Astrophysics Data System (ADS)

The direct deposition of piezoelectric thin films on thin substrates offers an appealing technology for the realization of lightweight adjustable mirrors capable of sub-arcsecond resolution. This solution will make it possible to realize X-ray telescopes with both large effective area and exceptional angular resolution and, in particular, it will enable the realization of the adjustable optics for the proposed mission Square Meter Arcsecond Resolution X-ray Telescope (SMART-X). In the past years we demonstrated for the first time the possibility of depositing a working piezoelectric thin film (1-5 um) made of lead-zirconate-titanate (PZT) on glass. Here we review the recent progress in film deposition and influence function characterization and comparison with finite element models. The suitability of the deposited films is analyzed and some constrains on the piezoelectric film performances are derived. The future steps in the development of the technology are described.

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

2012-10-01

257

Damage evaluation based on a wave energy flow map using multiple PZT sensors.  

PubMed

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

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

2014-01-01

258

Identification of crystalline elastic anisotropy in PZT ceramics from in-situ blocking stress measurements  

NASA Astrophysics Data System (ADS)

High energy x-ray diffraction measurements of lattice strains were performed on a rhombohedral Lead Zirconate Titanate ceramic (PZT 55-45) under combinations of applied electric field and compressive stress. These measurements allow the construction of blocking stress curves for different sets of crystallographic orientations which reflect the single crystal elastic anisotropy. A micro-mechanical interpretation of the results is then proposed. Assuming cubic symmetry for the crystalline elastic stiffness tensor and isotropy for the macroscopic elastic properties, the elastic properties of the single crystal are extracted from the measured data. An anisotropy ratio close to 0.3 is found (compared to 1 for isotropic materials). The high level of anisotropy found in this work suggests that crystalline elastic anisotropy should not be neglected in the modelling of ferroelectric materials.

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

2014-05-01

259

Influence of the process parameters on the structural and electric properties of ferroelectric and antiferroelectric PZT thin films realized on stainless steel by a Sol–gel derived method  

Microsoft Academic Search

Pb\\u000a x\\u000a ZryTi1?yO3 thin films were prepared by a modified Sol–gel method using alkoxides precursor compounds and spin-coating onto RuO2 coated stainless steel substrates. Depending on the zirconate\\/titanate ratio, both, ferroelectric and antiferroelectric behaviour\\u000a has been obtained. Oxidation of the metal substrate due to the PZT crystallization process was studied in order to verify\\u000a the influence of the heat treatment

Raynald Seveno; Hartmut Gundel

2007-01-01

260

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

NASA Astrophysics Data System (ADS)

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

Ortega Achury, Nora Patricia

261

Development of dual PZT transducers for reference-free crack detection in thin plate structures.  

PubMed

A new Lamb-wave-based nondestructive testing (NDT) technique, which does not rely on previously stored baseline data, is developed for crack monitoring in plate structures. Commonly, the presence of damage is identified by comparing "current data" measured from a potentially damaged stage of a structure with "baseline data" previously obtained at the intact condition of the structure. In practice, structural defects typically take place long after collection of the baseline data, and the baseline data can be also affected by external loading, temperature variations, and changing boundary conditions. To eliminate the dependence on the baseline data comparison, the authors previously developed a reference-free NDT technique using 2 pairs of collocated lead zirconate titanate (PZT) transducers placed on both sides of a plate. This reference-free technique is further advanced in the present study by the necessity of attaching transducers only on a single surface of a structure for certain applications such as aircraft. To achieve this goal, a new design of PZT transducers called dual PZT transducers is proposed. Crack formation creates Lamb wave mode conversion due to a sudden thickness change of the structure. This crack appearance is instantly detected from the measured Lamb wave signals using the dual PZT transducers. This study also suggests a reference-free statistical approach that enables damage classification using only the currently measured data set. Numerical simulations and experiments were conducted using an aluminum plate with uniform thickness and fundamental Lamb waves modes to demonstrate the applicability of the proposed technique to reference-free crack detection. PMID:20040449

Sohn, Hoon; Kim, Seuno Bum

2010-01-01

262

Microstructure et propriétés électriques des couches minces de PZT par procédé sol-gel  

NASA Astrophysics Data System (ADS)

Sol-gel method has been used for PZT thin films deposition onto platinized silicon substrates. PZT thin films microstructure depends on the platinum electrode preparation and the thermal treatment duration. PZT is nucleated under a crystalline form generally described as " rosette ". The influence of the platinum electrode morphology on the final grain size and the effect of the titanium as a contact layer between the platinum and the silicon have been investigated. Different thermal treatments have been investigated : the Rapid Thermal Annealing (RTA) method avoids pyrochlore phase formation and leads to small grain sizes. Electrical measurements have been done using top electrodes (platinum) obtained by microlithography. The influence of the parameters described on the hysteresis loop and resistivity is shown. Le dépôt de titano-zirconate de plomb (PZT) par centrifugation sur des substrats de silicium recouverts de platine est réalisé par un procédé du type " sol-gel ". La microstructure des couches obtenues dépend des paramètres suivants : préparation de l'électrode de base et durée du traitement thermique de densification. La nucléation de la phase pérovskite se fait sous la forme de " rosettes ". On décrit l'influence de la couche d'accrochage du platine (sous-couche de titane) et de la morphologie de l'électrode de base sur la taille de grains finale. La méthode du recuit rapide, associée à un prétraitement de l'électrode de base, permet à la fois d'éviter la formation de phase pyrochlore et de former des grains fins et homogènes. Les caractérisations électriques des couches sont faites sous pointes avec des électrodes supérieures réalisées par microlithographie. L'impact des différents paramètres cités plus hauts sur le cycle d'hystérésis est montré.

Faure, S. P.; Hector, J.; Gaucher, P.; Ganne, J. P.

1994-10-01

263

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

PubMed

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 (CO(2) ), 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 constant epsilon, remanent polarization value P(r), and coercive field strength E(c) of PZT films directly deposited onto a SUS-based piezoelectric actuator substrate annealed by CO(2) laser irradiation at 850 degrees C improved with increasing film thickness, and for films thicker than 25 microm, epsilon 800, P(r) 40 microC/cm(2), and E(c) 45 kV/cm. In contrast, the displacement of the SUS-based actuator with the laser-annealed PZT thick film decreased with increasing film thickness. PMID:18519203

Baba, S; Tsuda, H; Akedo, J

2008-05-01

264

Solid state NMR as a new approach for the structural characterization of rare-earth doped lead lanthanum zirconate titanate laser ceramics  

NASA Astrophysics Data System (ADS)

To facilitate the design of laser host materials with optimized emission properties, detailed structural information at the atomic level is essential, regarding the local bonding environment of the active ions (distribution over distinct lattice sites) and their extent of local clustering as well as their population distribution over separate micro- or nanophases. The present study explores the potential of solid state NMR spectroscopy to provide such understanding for rare-earth doped lead lanthanum zirconate titanate (PLZT) ceramics. As the NMR signals of the paramagnetic dopant species cannot be observed directly, two complementary approaches are utilized: (1) direct observation of diamagnetic mimics using 45Sc NMR and (2) study of the paramagnetic interaction of the constituent host lattice nuclei with the rare-earth dopant, using 207Pb NMR lineshape analysis. 45Sc MAS NMR spectra of scandium-doped PLZT samples unambiguously reveal scandium to be six-coordinated, suggesting that this rare-earth ion substitutes in the B site. Static 207Pb spin echo NMR spectra of a series of Tm-doped PLZT samples reveal a clear influence of paramagnetic rare-earth dopant concentration on the NMR lineshape. In the latter case high-fidelity spectra can be obtained by spin echo mapping under systematic incrementation of the excitation frequency, benefiting from the signal-to-noise enhancement afforded by spin echo train Fourier transforms. Consistent with XRD data, the 207Pb NMR lineshape analysis suggests that statistical incorporation into the PLZT lattice occurs at dopant levels of up to 1 wt.% Tm 3+, while at higher levels the solubility limit is reached.

Mohr, Daniel; de Camargo, Andrea S. S.; Schneider, José F.; Queiroz, Thiago B.; Eckert, Hellmut; Botero, Ériton R.; Garcia, Ducinei; Eiras, José A.

2008-10-01

265

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

SciTech Connect

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}.

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

1995-04-27

266

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

PubMed

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

Ploss, Bernd; Krause, Markus

2007-12-01

267

Evaluation of Low-Temperature Processing of Lead Zirconate Titanate (53\\/47) Ceramics Derived from 1-Propanol-Based Sol-Gel Stock Solutions  

Microsoft Academic Search

Nanoscale technology will lead to the next material revolution, particularly in terms of sol-gel method assembly in nanostructured devices. In this research, PbZr0.53Ti0.47O3 (PZT) ceramics with gel powder synthesized by the chemical solution deposition (CSD) method utilizing less hazardous propyl alcohol as a solvent were developed. The PZT solutions were transparent and no precipitates were formed with a reflux time

Long Wu; Bing-Huei Chen; Ten-Yi Chang; Jow-Lay Huang; Cheng-Liang Huag

2002-01-01

268

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

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

269

Powering low-power implants using PZT transducer discs operated in the radial mode  

NASA Astrophysics Data System (ADS)

This paper reports experimental results that are used to compare operation characteristics of lead zirconate titanate (PZT) piezoelectric ceramic discs operated in the radial mode. The devices are driven to radially vibrate at their lowest fundamental resonant frequency and thus transmit and receive power when immersed in a liquid phantom. A number of 1 mm × 10 mm (thickness × diameter) PZT discs are characterized experimentally within a propagation tank and results discussed. On the basis of these measured characteristics, a novel application is developed and reported for the first time. This consists of a tuned LC resonator circuit which is used at the receiving disc to maximize sensitivity as well as a Seiko start-up IC S-882Z which is employed to charge a capacitor that drives a PIC microcontroller (?C) once the voltage exceeds 2 V DC. We show that a mean input power of 486 mW RMS results in 976 ?W RMS received over a range of 80 mm and that this is sufficient to periodically (every 60 s) power the ?C to directly drive a red LED for 5 ms with a current of 4.8 mA/flash. This approach is suitable for low-power, periodically activated analogue bio-implant applications.

Sanni, Ayodele; Vilches, Antonio

2013-11-01

270

Synthesis and Characterization of PZT Ferroelectric Nanocrystals Current Measurement  

Microsoft Academic Search

Ferroelectric lead zirconium titanate (PZT) has been used in FeRAMs, which are expected to become common large capacity devices. We have extensively studied PZT thin films and their micro-processing. However, there are several problems of degradation by crystal defects at grain boundaries in thin films and surface damage by microfabrication. Self-assembled nanocrystals are useful for solving these problems. However, position

K. Kubo; M. Echizen; T. Nishida; T. Takeda; K. Uchiyama; T. Shiosaki

2007-01-01

271

Preparation and Characterization of PZT Films Fabricated on Si Substrate  

Microsoft Academic Search

Lead zirconium titanate (PZT) films (Zr\\/Ti=45:55) with a high dielectric constant are prepared successfully on the low-resistance\\u000a Si substrate in sol–gel dip-coating process with PT film used as the buffer layer. The dielectric and ferroelectric properties\\u000a of the films as well as the relationship between crystallization and preparing condition are studied. It is shown that the\\u000a PZT ferroelectric thin films

Ying Yang

2006-01-01

272

Ion-beam sputtering deposition and magnetoelectric properties of layered heterostructures (FM/PZT/FM)n, where FM - Co or Ni78Fe22  

NASA Astrophysics Data System (ADS)

Magnetoelectric properties of layered heterostructures (FM/PZT/FM)n (n? 3) obtained by ion-beam sputtering deposition of ferromagnetic metal (FM), where FM is the cobalt (Co) or permalloy Ni78Fe22, onto ferroelectric ceramic based on lead zirconate titanate (PZT) have been studied. The polished ferroelectric plates in thickness from 400 to 20 ?m were subjected to finished treatment by ion-beam sputtering. After plasma activation they were covered by the ferromagnetic films from 1 to 6 ?m in thickness. Enhanced characteristics of these structures were reached by means of both the thickness optimization of ferroelectric and ferromagnetic layers and obtaining of ferromagnetic/ferroelectric interfaces being free from defects and foreign impurities. Assuming on the basis of analysis of elastic stresses in the ferromagnetic film that the magnetoelectric effect forms within ferromagnetic/ferroelectric interface, the structures with 2-3 ferromagnetic layers were obtained. In layered heterostructure (Py/PZT/Py)3, the optimal thickness of ferromagnetic film was 2 ?m, and outer and inner ferroelectric layers had 20 ?m and 80 ?m in thickness, respectively. For such structure the maximal magnetoelectric voltage coefficient of 250 mV/(cm Oe) was reached at a frequency 100 Hz in magnetic field of 0.25 T at room temperature. The structures studied can serve as energy-independent elements detecting the change of magnetic or electric fields in electronic devices based on magnetoelectric effect.

Stognij, Alexander; Novitskii, Nikolai; Sazanovich, Andrei; Poddubnaya, Nadezhda; Sharko, Sergei; Mikhailov, Vladimir; Nizhankovski, Viktor; Dyakonov, Vladimir; Szymczak, Henryk

2013-08-01

273

Measurement of effective piezoelectric coefficients of PZT thin films for energy harvesting application with interdigitated electrodes.  

PubMed

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

Chidambaram, Nachiappan; Mazzalai, Andrea; Muralt, Paul

2012-08-01

274

2.8 and 1.55 ?m emission from diode-pumped Er3+-doped and Yb3+ co-doped lead lanthanum zirconate titanate transparent ferroelectric ceramic  

NASA Astrophysics Data System (ADS)

This work reports the observation of intense emissions at 2.8 and 1.55 ?m from optical quality diode-pumped Er3+-doped lead lanthanum zirconate titanate (PLZT) transparent ferroelectric ceramic. Radiative properties were calculated using the Judd Ofelt theory, and the respective values of ?=0.09 and ?=0.94 were obtained. The effect of ytterbium co-doping the PLZT: Er3+ samples was investigated in an attempt to increase intensities. It was found that Yb3+-->Er3+ energy transfer processes, that favor Er3+ upconversion, are detrimental to the efficiency of midinfrared emissions. Even so, the advantageous spectroscopic characteristics of PLZT: Er3+ associated with its excellent thermal and mechanical properties, indicate it is a potential cost-effective laser active media.

de Camargo, A. S. S.; Botero, É. R.; Andreeta, É. R. M.; Garcia, D.; Eiras, J. A.; Nunes, L. A. O.

2005-06-01

275

Lead Zirconate Titanate (LZT) Ceramics.  

National Technical Information Service (NTIS)

Tests of batch-to-batch reproducibility of LZT powders made by molten salt synthesis were carried out by measuring the properties of ceramics fired from them. Individual post-poling dielectric constants and planar coupling coefficients lay within plus or ...

J. H. Rosolowski R. H. Arendt J. W. Szymaszek

1978-01-01

276

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

NASA Astrophysics Data System (ADS)

Piezoelectric microelectromechanical systems (MEMS) are currently used in inkjet printers and precision resonators; numerous additional applications are being investigated for sensors, low-voltage actuators, and transducers. This work was aimed at improving piezoelectric MEMS by taking two approaches: 1) identifying factors affecting the piezoelectric response of ferroelectric thin films and 2) demonstrating integration of these films into a high frequency array transducer. It was found that there are several key factors influencing the piezoelectric response of thin films for a given material composition. First, large grain size improves the piezoelectric response. This was demonstrated using chemical solution deposited lead nickel niobate -- lead zirconate titanate (0.3)Pb(Ni 0.33Nb0.67)O3 - (0.7)Pb(Zr0.45Ti 0.55O3), (PNN-PZT) ferroelectric thin films. It was shown that this composition allows greater microstructural control than does PZT. Dielectric permittivities ranging from 1350 to 1520 and a transverse piezoelectric coefficient e31,f as high as -- 9.7 C/m 2 were observed for films of about 0.25 mum in thickness. The permittivity and piezoelectric response as well as extrinsic contributions to the dielectric constant increased by 14 and 12 % respectively for samples with grain sizes ranging from 110 to 270 nm. A second factor influencing the piezoelectric response is film composition with respect to the morphotropic phase boundary (MPB). The composition dependence of the dielectric and piezoelectric nonlinearities was characterized in epitaxially grown (0.3)Pb(Ni0.33Nb0.67)O3-(0.7)Pb(Zr xTi1-xO3) thin films deposited on SrTiO 3 to minimize the influence of large-angle grain boundaries. Tetragonal, MPB and rhombohedral films were prepared by changing the Zr/Ti ratio. The largest dielectric and piezoelectric nonlinearities were observed for the rhombohedral sample; this resulted from a higher domain wall mobility due to a smaller ferroelectric distortion and superior crystal quality. Thirdly, changes in the mechanical boundary conditions experienced by a ferroelectric thin film were found to influence both the properties and the length scale for correlated motion of domain walls. Microfabrication was employed to release the PZT films from the Si substrate. Nonlinear piezoelectric maps, by band excitation piezoforce microscopy, showed formation of clusters of higher nonlinear activities of similar size for clamped PZT films with different microstructures. However PZT films that had been released from the Si substrate showed a distinct increase in the correlation length associated with coupled domain wall motion, suggesting that the local mechanical boundary conditions, more than microstructure or composition govern the domain wall dynamics. Release of both the local and the global stress states in films produced dielectric nonlinearities comparable to those of bulk ceramics. The second research direction was targeted at demonstrating the functionality of a one dimensional transducer array. A diaphragm geometry was used for the transducer arrays in order to benefit from the unimorph-type displacement of the PZT-SiO2 layers. For this purpose, the PZT and remaining films in the stack were patterned using reactive ion etching and partially released from the underlying silicon substrate by XeF2 etching from the top. Admittance measurements on the fabricated structures showed resonance frequencies at ˜40 MHz for a 80 mum diameter-wide diaphragms with a PZT thickness of 1.74 mum. In-water transmit and receive functionalities were demonstrated. A bandwidth on receive of 80 % centered at 40 MHz was determined during pitch-mode tests.

Griggio, Flavio

277

Direct observation of single domains in poled (111) PZT (PbZr 0.25Ti 0.75O 3) films  

NASA Astrophysics Data System (ADS)

Films of (111) oriented poled ferroelectric lead zirconate titanate (PZT) crystallites on (100)Si/SiO 2/(111) Pt were investigated by scanning tunneling microscopy (STM), atomic force microscopy (AFM) and small angle X-ray scattering (SAXS). SAXS investigations allowed to estimate a mean value of domain thickness of 17.5 nm. Exertion of stress (5.1×10 4 N m -2) to the film resulted in an increase of domain width of ˜1%. After metallization of the PZT surface with a Cr-Ni film of 5.2 nm or a Ti film of 5.0 nm thickness, domains were visible by STM measurements as parallel stripes on the surface with a width of 15-20 nm. A downward vertical corrugation of 1.0-1.5 nm typically occurred at the intersection site of domain walls with the surface. Its presence is ascribed to shear strain originating from coherency defects in the interface. High resolution AFM with electron beam deposited supertips on unmetallized samples revealed areas of typically several micrometers in diameter showing crystallites with perfectly aligned domains of 10-15 nm width. The domains formed parallel slabs of twinned-crystallites with their polarization c-axis changing alternately from [001] to [010] direction. For a fully poled (111) PZT film, the c-axis of each (90°) domain is inclined towards the surface by 35° and tilted against the surface normal by +45 or -45°, respectively. These results generally confirm the Speck-Streiffer-Pompe-Romanov domain model which predicts for a (111) PZT film of 500 nm thickness a polyvariant with alternating (90°) domains of 16.4 nm width.

Zybill, C. E.; Boubekeur, H.; Radojkovic, P.; Schwartzkopff, M.; Hartmann, E.; Koch, F.; Groos, G.; Rezek, B.; Bruchhaus, R.; Wersing, W.

1999-10-01

278

Processing effects for integrated PZT: Residual stress, thickness, and dielectric properties  

NASA Astrophysics Data System (ADS)

This dissertation focuses on the integration of lead zirconate titanate (PZT) films on Pt/Ti/SiO2//Si, and the effect of on properties. Direct deposition of PZT on Si will lead to on-chip power capacitors, non-volatile memory cells, and vibration sensors. However, previous research indicates that the dielectric, ferroelectric and piezoelectric response characteristics for the devices are often inferior to bulk specimens. Property variations have been attributed to changes in several major variables including, chemical composition, phase content, grain size, crystallographic orientation, film thickness, and stress, each of which, in turn, can depend on processing. The first goal of this work was to design a sol-gel processing methodology to control all major variables except film thickness and stress, thus isolating their respective effects on properties. All specimens were verified to be of the Pb(Zr0.53Ti0.47)O3 composition, in the perovskite structure, with a constant grain size of 110nm, and with (111) fiber texture. PZT film thickness was varied from 95nm to 500nm and residual stress was measured to be either 150 or 180MPa, biaxial tensile, depending on thickness. These specimens allowed for new insights into the fundamental differences between bulk materials and thin films. A series-capacitor model accounted for the observed dilution in room-temperature K from >900 to ˜600 as film thickness decreased, but could not account for the absence of the expected dielectric anomaly at high temperatures. Instead, a stress-induced distributed phase transformation related to the polycrystalline nature of the film was proposed to account for the observed behavior. Residual stress reduced the spontaneous polarization values in these specimens to 32muC/cm 2 from the predicted stress-free value of 50muC/cm2. An increase in coercive field was attributed to interfacial capacitance and residual stress, whereas a decrease of 30MPa tensile stress resulted in an increase of d33 from 33 to 65pm/V, irrespective of changes in film thickness. These results isolated, for the first time, the effects of stress and thickness on the dielectric, ferroelectric and piezoelectric properties of PZT films without convolution from the other major variables. The research provides a guideline for the tailoring of properties by modifying mechanical stress in polarizable and deformable thin films.

Ong, Ryan Jason

279

Fabrication and Characterization of PZT Thick Films for Sensing and Actuation  

PubMed Central

Lead Zirconate Titanate oxide (PZT) thick films with thicknesses of up to 10 mm were developed using a modified sol-gel technique. Usually, the film thickness is less than 1 mm by conventional sol-gel processing, while the electrical charge accumulation which reveals the direct effect of piezoelectricity is proportional to the film thickness and therefore restricted. Two approaches were adopted to conventional sol-gel processing – precursor concentration modulation and rapid thermal annealing. A 10 ?m thick film was successfully fabricated by coating 16 times via this technique. The thickness of each coating layer was about 0.6 mm and the morphology of the film was dense with a crack-free area as large as 16 mm2. In addition, the structure, surface morphology and physical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) and electrical performance. The dielectric constant and hysteresis loops were measured as electric characteristics. This study investigates the actuation and sensing performance of the vibrating structures with the piezoelectric thick film. The actuation tests demonstrated that a 4 mm × 4 mm × 6.5 mm PZT film drove a 40 mm × 7 mm × 0.5 mm silicon beam as an actuator. Additionally, it generated an electrical signal of 60 mVpp as a sensor, while vibration was input by a shaker. The frequencies of the first two modes of the beam were compared with the theoretical values obtained by Euler-Bernoulli beam theory. The linearity of the actuation and sensing tests were also examined.

Jang, Ling-Sheng; Kuo, Kuo-Ching

2007-01-01

280

Effects of electric field on the fracture toughness (KIc) of ceramic PZT  

NASA Astrophysics Data System (ADS)

This work was motivated by the observation that a small percentage of the ceramic lead zirconate titanate (PZT) parts in a device application, one that requires an electrode pattern on the PZT surface, developed fatigue cracks at the edges of the electrodes; yet all of the parts were subjected to similar loading. To obtain additional information on the fracture behavior of this material, similar specimens were run at higher voltage in the laboratory under a microscope to observe the initiation and growth of the fatigue cracks. A sequence of experiments was next performed to determine whether there were fracture toughness variations that depended on material processing. Plates were cut from a single bar in different locations and the Vickers indentation technique was used to measure the relative fracture toughness as a function of position along the bar. Small variations in toughness were found, that may account for some of the devices developing fatigue cracks and not others. Fracture toughness was measured next as a function of electric field. The surface crack in flexure technique was modified to apply an electric field perpendicular to a crack. The results indicate that the fracture toughness drops under a positive electric field and increases under a negative electric field that is less than the coercive field, but as the negative coercive field is approached the fracture toughness drops. Examination of the fracture surfaces using an optical microscope and a surface profilometer reveal the initial indentation crack shape and (although less accurately) the crack shape and size at the transition from stable to unstable growth. These results are discussed in terms of a ferroelastic toughening mechanism that is dependent on electric field.

Goljahi, Sam; Lynch, Christopher S.

2013-09-01

281

Compensator design for hysteresis of a stacked PZT actuator using a congruency-based hysteresis model  

NASA Astrophysics Data System (ADS)

This paper proposes a rate-independent hysteresis compensator for a stacked PZT (lead zirconate titanate) actuator. From a congruency-based hysteresis (CBH) model which is derived from the inherent properties of this actuator, especially the congruency, a feedforward compensator associated with it is developed. The formulation of the proposed compensator is based on an assumption that the inverse operator also possesses the same properties as the CBH model does. This implies that the compensator also possesses properties such as the wiped-out loop closing between the consecutive control points and congruency. Consequently, the expressions for the compensator can be conducted by exploiting the equations for the CBH model in two cases of monotonic increase and monotonic decrease of input excitation. In order to assess the performance of the compensator, several experiments in both open-loop and closed-loop controls are undertaken. In the open-loop control experiment, the performance of the feedforward compensator using the CBH model is compared with the classical Preisach model-based one in three cases of reference waveforms. In the closed-loop control experiment, the proposed compensator is incorporated into a PID (proportional-integral-derivative) control system and the performance of this integrated system is then evaluated and compared to that of the PID with and without compensator.

Nguyen, Phuong-Bac; Choi, Seung-Bok

2012-01-01

282

Characterization of a Pt-core PZT fiber/Al matrix composite  

NASA Astrophysics Data System (ADS)

The objective of this study is to design and characterize a piezoelectric composite and evaluate its suitability for viscosity-measuring applications, i.e., monitoring the coagulation rate of blood. The composite is manufactured of a platinum-core lead zirconate titanate (PZT) fiber inserted into an aluminum matrix. This study characterizes the described composite by testing its impedance, capacitance, voltage sensitivity response to vibrational inputs, and deformation due to electrical input. As actuators, different voltage inputs are fed into the probes and displacement is measured with results on the range of nanometers. As sensors, the devices are used to monitor cantilever beam vibrations. The probe's response is in the mV range and follows the same pattern as an accelerometer. Additional tests in air, water, and deionized water are carried out to evaluate the sensor's suitability for measuring viscosity using two probes: one as an actuator and the other as a sensor. Results of the gain and phase between the two probes indicate that the phase shift may be used as an indicator of viscosity changes. The first significant phase shift was measured as 2.45, 2.77, and 4.065x107Hz, for water, air, and oil, respectively, which is directly proportional to the kinematic viscosity of each fluid.

Richeson, M.; Erturun, U.; Waxman, R.; Mossi, K.; Kunikata, J.; Asanuma, H.

2010-03-01

283

Low-Temperature Processing of PZT Thick Film by Seeding and High-Energy Ball Milling and Studies on Electrical Properties  

NASA Astrophysics Data System (ADS)

Lead zirconate titanate thick film with molecular formula PbZr0.52Ti0.42O3 (PZT) was prepared by a modified conventional sol-gel method through seeding and high-energy ball milling, resulting in perovskite phase formation at lower temperatures. The ball-milling time was optimized by keeping the seed particle loading (5 wt.%) constant in the sol-gel solution. This methodology helped in reduction of the crystalline phase formation temperature to 300°C, which is much lower than that reported in the literature (450°C). The well-established perovskite phase was confirmed by x-ray diffraction (XRD) analysis. Scanning electron microscopy (SEM) of PZT films revealed uniform and crystalline microstructure. Film prepared by this methodology showed higher spontaneous polarization (2.22 ?C/cm2), higher capacitance (1.17 nF), and low leakage current density (18 ?A/cm2). The results obtained from ferroelectric characterization showed a strong correlation with the XRD and SEM results.

Dutta, Soma; Jeyaseelan, A. Antony; Sruthi, S.

2013-12-01

284

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

NASA Astrophysics Data System (ADS)

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

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

2009-12-01

285

Studies on dielectric and magnetic properties of (x) Ni0.2Co0.8Fe2O4+(1-x) barium lead zirconate titanate magnetoelectric composites  

NASA Astrophysics Data System (ADS)

The piezomagnetic (ferrite)-piezoelectric (ferroelectric) composites with compositions (x) Ni0.2Co0.8Fe2O4+(1-x) Ba0.8Pb0.2Zr0.8Ti0.2O3 [barium lead zirconate titanate (BPZT)] in which x varies as 0.0, 0.15, 0.30, 0.45, and 1.0 mol % were prepared by conventional ceramic double-sintering method. The presence of constituent phases in the composites was confirmed by x-ray diffraction studies and the average grain size was calculated by using scanning electron microscopy. The dielectric constant (?') and loss tangent (tan ?) were measured as a function of frequency in the frequency range 20 Hz-1 MHz. Variation of the dielectric constant and loss tangent with temperature at four fixed frequencies (1, 10, and 100 KHz and 1 MHz) was studied. The ac conductivity was studied to understand the conduction mechanism in terms of small polarons. The hysteresis behavior was studied to understand the magnetic properties such as saturation magnetization (Ms) and magnetic moment (?B). The static magnetoelectric (ME) voltage coefficient was measured as function of applied dc magnetic field and variation in ME response has been explained in terms of the content of piezomagnetic phase and the intensity of applied magnetic field. The maximum ME conversion factor of 536 ?V/cm Oe was observed for 15% Ni0.2Co0.8Fe2O4+85% BPZT composite.

Bammannavar, B. K.; Naik, L. R.; Chougule, B. K.

2008-09-01

286

Schottky barrier heights of tantalum oxide, barium strontium titanate, lead titanate, and strontium bismuth tantalate  

Microsoft Academic Search

The Schottky barrier heights of various metals on the high permitivity oxides tantalum pentoxide, barium strontium titanate, lead zirconate titanate, and strontium bismuth tantalate have been calculated as a function of the metal work function. It is found that these oxides have a dimensionless Schottky barrier pinning factor S of 0.28-0.4 and not close to 1 because S is controlled

J. Robertson; C. W. Chen

1999-01-01

287

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

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

288

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

SciTech Connect

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.

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

2010-08-01

289

A large-scan-angle piezoelectric MEMS optical scanner actuated by a Nb-doped PZT thin film  

NASA Astrophysics Data System (ADS)

Resonant 1D microelectromechanical systems (MEMS) optical scanners actuated by piezoelectric unimorph actuators with a Nb-doped lead zirconate titanate (PNZT) thin film were developed for endoscopic optical coherence tomography (OCT) application. The MEMS scanners were designed as the resonance frequency was less than 125 Hz to obtain enough pixels per frame in OCT images. The device size was within 3.4 mm × 2.5 mm, which is compact enough to be installed in a side-imaging probe with 4 mm inner diameter. The fabrication process started with a silicon-on-insulator wafer, followed by PNZT deposition by the Rf sputtering and Si bulk micromachining process. The fabricated MEMS scanners showed maximum optical scan angles of 146° at 90 Hz, 148° at 124 Hz, 162° at 180 Hz, and 152° at 394 Hz at resonance in atmospheric pressure. Such wide scan angles were obtained by a drive voltage below 1.3 Vpp, ensuring intrinsic safety in in vivo uses. The scanner with the unpoled PNZT film showed three times as large a scan angle as that with a poled PZT films. A swept-source OCT system was constructed using the fabricated MEMS scanner, and cross-sectional images of a fingertip with image widths of 4.6 and 2.3 mm were acquired. In addition, a PNZT-based angle sensor was studied for feedback operation.

Naono, Takayuki; Fujii, Takamichi; Esashi, Masayoshi; Tanaka, Shuji

2014-01-01

290

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

SciTech Connect

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.

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

2003-07-01

291

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.

2000-01-01

292

PZT behavior in cyclic strain environments  

NASA Astrophysics Data System (ADS)

This paper presents results of an experiment designed to determine the impact of repeated strain cycles on lead ziconate titanate (PZT) transducers affixed to an aluminum test specimen. The goal of this research effort is to determine the impact of three cyclic strain levels on PZTs affixed with two different glue types. PZT transducers are evaluated because they are one of the leading health monitoring technologies used in aircraft structures due to their ability to transmit and receive Lamb Waves. Analysis of changes in the received signals can indicate the presence of structural damage. This monitoring paradigm can only be successful if signal changes due to exposure to aircraft environmental factors (temperature/strain/pressure cycles, etc) over time can be clearly identified and characterized. This paper presents the results and initial analysis of experiments to determine the changes in signal responses due to cyclic mechanical strain. Results indicate cyclic strain at 800 ?? has no effect to 510K cycles, while cyclic strain at 1700 and 2600 ?? both cause signal loss to varying degrees.

Kuhn, Jeffrey D.; Swenson, Eric D.; Soni, Som R.

2009-03-01

293

Dynamic Electromechanical Characterization of Axially Poled PZT 95/5  

SciTech Connect

We are conducting a comprehensive experimental study of the electromechanical behavior of poled PZT 95/5 (lead zirconate titattate). As part of this study, eight plane-wave tests have been conducted on axially poled PZT 95/5 at stress levels ranging from 0.9 to 4.6 GPa, using VISAR and electrical diagnos- tics. Observed wave velocities were slightly decreased from ultrasonic vahtes, by contrast' with unpoled samples. Compression waveforms show a step at 0.6 GPa more marked than for normally poled or unpoled samples; this may correspond to a poling effect on the ferroelectric/antiferroelectric transition. A similar step is observed on release. The released charge upon loading to 0.9 GPa is consistent with nearly complete depoling. Loading to higher stresses gave lower currents (factor of 10), suggesting shock-induced conduc- tivity or electrical breakdown.

Chhabildas, Lalit C.; Furnish, Michael D.; Montgomery, Stephen T.; Setchell, Robert E.

1999-06-25

294

Piezoelectric and mechanical properties of fatigue resistant, self-healing PZT–ionomer composites  

NASA Astrophysics Data System (ADS)

Piezoelectric ceramic–polymer composites with 0–3 connectivity were fabricated using lead zirconium titanate (PZT) powder dispersed in an ionomer (Zn ionomer) and its reference ethylene methacrylic acid copolymer (EMAA) polymer matrix. The PZT–Zn ionomer and PZT–EMAA composites were prepared by melt extrusion followed by hot pressing. The effects of poling conditions such as temperature, time and electric field on the piezoelectric properties of the composites were investigated. The experimentally observed piezoelectric charge coefficient and dielectric constant of the composites were compared with theoretical models. The results show that PZT–Zn ionomer composites have better piezoelectric properties compared to PZT–EMAA composites. The static and fatigue properties of the composites were investigated. The PZT–Zn ionomer composites were found to have excellent fatigue resistance even at strain levels of 4%. Due to the self-healing capabilities of the ionomer matrix, the loss of piezoelectric properties after high strain tensile cyclic loading could be partially recovered by thermal healing.

James, N. K.; Lafont, U.; van der Zwaag, S.; Groen, W. A.

2014-05-01

295

Uniaxial Compression Experiments on Lead Zirconate Titanate 95\\/5-2Nb Ceramic: Evidence for an Orientation-Dependent, ''Maximum Compressive Stress'' Criterion for Onset of the Ferroelectric - Antiferroelectric Polymorphic Transformation  

Microsoft Academic Search

Some time ago we presented evidence that, under nonhydrostatic loading, the F{sub R1} â A{sub O} polymorphic transformation of unpoled PZT 95\\/5-2Nb (PNZT) ceramic began when the maximum compressive stress equaled the hydro-static pressure at which the transformation otherwise took place. Recently we showed that this simple criterion did not apply to nonhydrostatically compressed, poled ceramic. However, unpoled ceramic is

D. H. Zeuch; S. T. Montgomery; D. J. Holcomb

1999-01-01

296

Role of epitaxy in controlling the magnetic and magnetostrictive properties of cobalt ferrite-PZT bilayers  

NASA Astrophysics Data System (ADS)

Epitaxial thin films of cobalt ferrite (CFO) single layer and CFO-lead zirconium titanate (PZT) bilayers were deposited on single crystal MgO (1 0 0) and SrTiO3 (STO) (1 0 0) substrates by pulsed laser deposition. The structural properties were characterized using x-ray diffraction and atomic force microscopy. The magnetic properties of the as-grown thin films were measured at 10 and 300 K in both parallel and perpendicular magnetic fields. The CFO-PZT bilayer films showed enhanced or reduced values of magnetization as compared with those of the CFO single layer films depending on the substrate of deposition. A strain compression-relaxation mechanism was proposed in order to explain the structure-property relationships in the CFO-PZT bilayer thin films.

Mukherjee, D.; Dhakal, T.; Hyde, R.; Mukherjee, P.; Srikanth, H.; Witanachchi, S.

2010-12-01

297

Piezoelectric cantilever beams actuated by PZT sol-gel thin film  

Microsoft Academic Search

The mechanical response of piezoelectric cantilever beams actuated by sol-gel-derived lead zirconium titanate (PZT) thin film is reported. Small multilayered beams are used to analyse the converse piezoelectric effect and to measure the mechanical deflection of the beams with a standard interferometry method. Interferometric displacement measurements, electrical measurements and finite-element simulations are reported to determine the piezoelectric coefficient d31 of

Ph Luginbuhl; G.-A Racine; Ph Lerch; B Romanowicz; K. G Brooks; N. F de Rooij; Ph Renaud; N Setter

1996-01-01

298

Optical and electro-optic properties of micrometric thick lead zirconate titanate films on (Pb{sub 0.86},La{sub 0.14})TiO\\/glass  

Microsoft Academic Search

Highly (100)-oriented Pb(Zr{sub 0.52},Ti{sub 0.48})O (PZT) films of up to approx2.4 mum are deposited on the (Pb{sub 0.86},La{sub 0.14})TiO (PLT)-coated amorphous substrate by one cycle of sputtering and annealing. The films possess fibrous columnar nanostructures and vertically grow on the PLT\\/glass substrate. Microstructure analysis and property characterization indicate that the films possess very promising optical, waveguiding, and electro-optic (EO) properties,

M. M. Zhu; Z. H. Du; J. Ma

2009-01-01

299

Acoustic emission from different PZT  

Microsoft Academic Search

Acoustic Emissions (AE) in ferroelectrics originate from three major sources: domain pattern changes, electric discharges and microcracking. All three may play a significant roll as damage mechanisms for the long term reliability of these materials in actuator applications. In this publication, contributions of at least two mechanisms in commercial PZT's are presented and the feasibility of a unique assignment of

Doru C. Lupascu; Jürgen Nuffer; Jürgen Rödel

1999-01-01

300

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

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.

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

1995-10-01

301

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

NASA Astrophysics Data System (ADS)

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

Leontsev, Serhiy

302

Low- and high-frequency properties of electronic ceramics from titanate materials  

SciTech Connect

The electrical losses (tan {delta}) and equivalent series resistance of selected ceramic dielectrics were measured at frequencies of up to 2 GHz. Magnesium-titanate dielectrics have very low losses compared to BaTiO{sub 3}. Mixed titanate-zirconates have intermediate losses at low frequencies and uniquely affect the series resistance (R{sub s}) at high frequencies.

West, P.R. (Dielectric Labs. Inc., Cazenovia, NY (USA))

1987-01-01

303

Pb diffusion in zircon  

Microsoft Academic Search

Diffusion of Pb was characterized in natural and synthetic zircon under a range of conditions. In most experiments, mixtures of Pb sulfate and ground zircon were used as the sources of diffusant, with Pb depth profiles measured with Rutherford Backscattering Spectrometry (RBS). As complement to these “in-diffusion” experiments, “out-diffusion” experiments were run on both synthetic Pb-doped and natural zircon with

D. J Cherniak; E. B Watson

2001-01-01

304

Uniaxial Compression Experiments on Lead Zirconate Titanate 95/5-2Nb Ceramic: Evidence for an Orientation-Dependent, ''Maximum Compressive Stress'' Criterion for Onset of the Ferroelectric - Antiferroelectric Polymorphic Transformation  

SciTech Connect

Some time ago we presented evidence that, under nonhydrostatic loading, the F{sub R1} {r_arrow} A{sub O} polymorphic transformation of unpoled PZT 95/5-2Nb (PNZT) ceramic began when the maximum compressive stress equaled the hydro-static pressure at which the transformation otherwise took place. Recently we showed that this simple criterion did not apply to nonhydrostatically compressed, poled ceramic. However, unpoled ceramic is isotropic, whereas poled ceramic has a preferred crystallographic orientation and is mechanically anisotropic. If we further assume that the transformation depends not only on the magnitude of the compressive stress, but also its orientation relative to some feature(s) of PNZT's crystallography, then these disparate results can be qualitatively resolved. It has long been known that this transformation can be triggered in uniaxial compression. Our modified hypothesis makes two predictions for transformation of unpoled polycrystals under uniaxial stress: (i) the transformation should begin when the maximum compressive stress, {sigma}{sub 1}, equals the hydrostatic pressure for transformation, and (ii) a steadily increasing axial stress should be required to drive the transformation.

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

1999-07-26

305

Response of a pentagonal PZT element as a component of a 4pi real-time detector  

Microsoft Academic Search

A shell-structured detector has been proposed to monitor tiny space debris dust in real time This form was aimed at detecting hypervelocity particles free from the incident direction The simplest structure was accomplished in a dodecahedron that comprised twelve pentagonal elements each of which was fabricated from piezoelectric lead-zirconane-titanate PZT The pentagonal element was 9 cm 2 area and 1mm

T. Miyachi; M. Fujii; G. Kuraza; T. Iwaii; H. Ohashi; H. Shibata; T. Onishi; E. Gruen; R. Srama; N. Okada

2006-01-01

306

An ultrasonic micromotor using a bending cylindrical transducer based on PZT thin film  

Microsoft Academic Search

Ultrasonic motors have a good high-torque performance. In particular, it seems that cylinder-type ultrasonic motors are superior to disk- or ring-type ones in the sense of high-torque application. For miniaturization of the motor size, a simple structure of an ultrasonic transducer becomes effective. This paper presents an ultrasonic micromotor using a bending cylindrical transducer based on a lead zirconate titanate

Takeshi Morita; Minoru Kurosawa; Toshiro Higuchi

1995-01-01

307

Hybrid powder-sol–gel PZT thick films on metallic membranes for piezoelectric applications  

Microsoft Academic Search

A hybrid sol–gel-powder method was used to process 3–6?m thick lead zirconate titanate films via spin-coating a Ni-base alloy and silicon substrates. The films were crack free and possessed a fine microstructure. High effective piezoelectric coefficients, d33, of 250pm\\/V were obtained from piezoelectric hysteresis loops using a laser vibrometer. Crack free sensor membranes were obtained from these film heterostructures via

M. Es-Souni; S. Maximov; A. Piorra; J. Krause; C.-H. Solterbeck

2007-01-01

308

Ceramic with zircon coating  

NASA Technical Reports Server (NTRS)

An article comprises a silicon-containing substrate and a zircon coating. The article can comprise a silicon carbide/silicon (SiC/Si) substrate, a zircon (ZrSiO.sub.4) intermediate coating and an external environmental/thermal barrier coating.

Wang, Hongyu (Inventor)

2003-01-01

309

Molecular Structure of Zircon  

NSDL National Science Digital Library

Zircon (zirconium silicate) was found in Greece and Italy as far back as the 6th Century A.D. Zircon comes from the Persian word "zargun" which means gold-colored. Zircon has been used as a diamond substitute because it resembles diamond in luster and has been mistaken for diamonds by many experienced jewelers, although it is not the same as Cubic Zirconia. It can be brown, red, green, blue, yellow, black, violet, orange and colorless. A typical crystal of zircon is shaped like a tetragonal prism with four sided prisms at each end. Zircon can be found in Laacher Sea, Niedermendig and Germany, and is mined in Cambodia, Sri Lanka, Thailand, Myanmar, Australia, and other countries.

2002-09-06

310

Zircons are Forever  

NSDL National Science Digital Library

Zircons have been in the news lately because of the recent discovery that the chemical signature of the oldest known zircon crystal (4.4 billion years) suggests that water, and thus conditions for life on Earth, was present then. Geologists at the University of Wisconsin-Madison contributed to a large part of this study. Zircons are Forever is a newly posted feature page on the UW Geology and Geophysics Website. The text describes the basic chemistry of zircon and why it is an important mineral for studies of mantle formation. Particular emphasis is on stable isotope geochemistry. A hyperlinked bibliography leads to abstracts and plots of oxygen isotope values from papers by UW faculty and graduate students. Zircons are Forever adds a little more background to the recent headlines.

311

Effect of Ball Milling Time on the Electrical and Piezoelectric Properties of Barium Titanate Ceramics  

Microsoft Academic Search

Barium Titanate (BaTiO3) is the first piezoelectric ceramic developed and most widely used though for few decades it has been replaced by better performed lead based materials like PZT, PLZT, etc. for piezoelectric applications. Recently, however, due to the environmental concern caused by lead based materials, researchers have been giving importance to this material and trying to improve its piezoelectric

A. K. Nath; Chongtham Jiten; K. Chandramani Singh; Radhapiyari Laishram; O. P. Thakur; D. K. Bhattacharya

2010-01-01

312

RMS Titanic  

NSDL National Science Digital Library

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

Mr.taylor

2010-04-20

313

RMS TITANIC  

NSDL National Science Digital Library

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

Klooney

2010-04-20

314

The Titanic  

NSDL National Science Digital Library

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

Van Vooren, Ms.

2007-12-04

315

Interior of Titan.  

National Technical Information Service (NTIS)

General principles of Titan formation and evolution are addressed. Attention is focused on the volatile reservoir (defined as all constituents more volatile than water) of Titan's interior. Volatile poor models, in which Titan is like Granymede or Callist...

D. J. Stevenson

1992-01-01

316

Electrical properties of calcium modified PZT (52/48) ceramics  

NASA Astrophysics Data System (ADS)

To optimize the electrical properties of lead zirconate titanate, it was modified by calcium. Pb1-xCaxZr0.52Ti0.48O3, x=0.00, 0.02, 0.04, 0.06 and 0.10 composition, was prepared by the sol-gel technique. All the samples have been crystallized to a mixture of rhombohedral and tetragonal crystallographic phases. The dielectric constant increases with the increase in calcium concentration due to the increase in electronic polarization. The Curie temperature decreases with increase in calcium concentration of the sample. The ac conductivity of the sample obeys the Jonscher power law. The ac conductivity of the sample increases with the increase in calcium concentration. The impedance study shows the contribution from grain and grain boundary.

Kour, P.; Kumar, Pawan; Sinha, S. K.; Kar, Manoranjan

2014-07-01

317

Li diffusion in zircon  

NASA Astrophysics Data System (ADS)

Diffusion of Li under anhydrous conditions at 1 atm and under fluid-present elevated pressure (1.0-1.2 GPa) conditions has been measured in natural zircon. The source of diffusant for 1-atm experiments was ground natural spodumene, which was sealed under vacuum in silica glass capsules with polished slabs of zircon. An experiment using a Dy-bearing source was also conducted to evaluate possible rate-limiting effects on Li diffusion of slow-diffusing REE+3 that might provide charge balance. Diffusion experiments performed in the presence of H2O-CO2 fluid were run in a piston-cylinder apparatus, using a source consisting of a powdered mixture of spodumene, quartz and zircon with oxalic acid added to produce H2O-CO2 fluid. Nuclear reaction analysis (NRA) with the resonant nuclear reaction 7Li(p,?)8Be was used to measure diffusion profiles for the experiments. The following Arrhenius parameters were obtained for Li diffusion normal to the c-axis over the temperature range 703-1.151°C at 1 atm for experiments run with the spodumene source: D_{text{Li}} = 7.17 × 10^{ - 7} { exp }( - 275 ± 11 {text{kJmol}}^{ - 1} /{text{RT}}){text{m}}2 {text{s}}^{ - 1}. Diffusivities are similar for transport parallel to the c-axis, indicating little anisotropy for Li diffusion in zircon. Similar Li diffusivities were also found for experiments run under fluid-present conditions and for the experiment run with the Dy-bearing source. Li diffusion is considerably faster than diffusion of other cations in zircon, with a smaller activation energy for diffusion. Although Li diffusion in zircon is comparatively rapid, zircons will be moderately retentive of Li signatures at mid-crustal metamorphic temperatures, but they are unlikely to retain this information for geologically significant times under high-grade metamorphism.

Cherniak, D. J.; Watson, E. B.

2010-09-01

318

Development of Sol-Gel Precursor System for Direct-Patternable PZT Ferroelectric Films Containing La as a Dopant  

Microsoft Academic Search

Direct-patternable lanthanum substituted lead zirconate titanate (PLZT) films were prepared by sol-gel technique using orth-nitrobenzaldehyde as a photosensitive agent. PLZT films with various La concentration were formed on Pt(111)\\/Ti\\/SiO2\\/Si(100) substrate for direct-patterning of PLZT films and ferroelectric properties measurement. A well-defined and direct-patterned PLZT film was obtained and the improvement of leakage current density, fatigue resistance and dielectric constant with

Sangwoo Bae; Jae-Seob Hwang; Woo Sik Kim; Hyung-Ho Park; Tae-Song Kim

2005-01-01

319

Processing of Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} (PZT) ceramics from microwave and conventional hydrothermal powders  

SciTech Connect

Lead zirconium titanate (PZT) perovskite powders were synthesized without using any excess lead content by microwave hydrothermal method (M-H) at 122 C and conventional hydrothermal (C-H) method at 138 C. PZT powders prepared by both methods showed a particle size of less than 4 {micro}m. Pellets prepared from these powders and sintered at 1,250 C for 4 h, without any additives or sintering aids, showed densities in the range of 92--95% of theoretical density. Variation of relative permittivity and dissipation factor with temperature of these PZT pellets was studied. A maximum permittivity of 20,570, low dissipation factor of 0.002, and Curie temperature of 373 C were observed for sintered pellets prepared from PZT powders obtained by microwave hydrothermal method. The pellets prepared from PZT powders obtained by the conventional hydrothermal method showed a relative permittivity of 16,310, dissipation factor of 0.001, and Curie temperature of 351 C.

Abothu, I.R.; Liu, S.F.; Komarneni, S.; Li, Q.H.

1999-07-01

320

Pulsed-laser deposited amorphous-like PZT thin-films: Microstructure and optical properties  

Microsoft Academic Search

Amorphous lead–zirconate–titanate (Pb0.97Nd0.02(Zr0.55Ti0.45)O3, PNZT) thin-films were grown on single-crystal MgO(100) substrates at room temperature by pulsed laser deposition (PLD). Part of PNZT films was left as-deposited amorphous and others were post-annealed at temperatures from 100 to 400°C. X-ray diffraction (XRD) and scanning probe microscopy (SPM) were used to characterize the microstructure. Optical properties were analyzed using spectrophotometry at UV–vis–NIR and

J. Lappalainen; J. Puustinen; J. Hiltunen; V. Lantto

2010-01-01

321

Anomalous losses of lead in crystallization of the perovskite phase in thin PZT films  

NASA Astrophysics Data System (ADS)

A study has been performed of the mechanisms underlying evolvement of excess lead oxide from lead zirconate titanate films grown ex-situ in two different regimes by magnetron sputtering. In the first case, crystallization of the dense phase of perovskite passed through an intermediate "porous" phase, and in the second, straight through. It has been found that the anomalously large losses of lead are caused by migration of lead over interphase porous boundaries to the surface of the films and depend strongly on the regime of film preparation. The unusual variation of film composition with increasing annealing temperature has been discussed.

Pronin, V. P.; Senkevich, S. V.; Kaptelov, E. Yu.; Pronin, I. P.

2013-01-01

322

Modeling, Optimization, and Design of Efficient Initially Curved Piezoceramic Unimorphs for Energy Harvesting Applications  

Microsoft Academic Search

The piezoceramic, lead zirconate titanate (PZT), is capable of producing large voltages with relatively minimal currents in response to an applied mechanical load when employed in initially curved laminates. This study addresses the issue of optimizing design parameters of a curved PZT unimorph to maximize charge generation due to mechanical loading. A horizontally placed PZT unimorph structure generates surface charge

Hwan-Sik Yoon; Gregory Washington; Amita Danak

2005-01-01

323

PZT piezoelectric coefficient extraction by PZT-actuated micro-beam characterization and modeling  

Microsoft Academic Search

In this paper, we showed the realization and the characterization of a PZT-actuated micro-cantilever. The measurement and the modeling of its resonant frequency allow deducing the cantilever length. Using this value and combining the measurement and the modeling of the cantilever displacement amplitude at a given voltage, we extract PZT d31 piezoelectric coefficient as being 165±25 pm\\/V; which is among

F. Casset; M. Cueff; A. Suhm; G. Le Rhun; J. Abergel; M. Allain; C. Dieppedale; T. Ricart; S. Fanget; P. Renaux; D. Faralli; P. Ancey; A. Devos; E. Defay

2012-01-01

324

Piezoelectric Properties of a Porous PZT Ceramic.  

National Technical Information Service (NTIS)

A porous PZT material from a Japanese source was characterized for its piezoelectric properties. Initial values of 82 pC/N for the hydrostatic d constant and 0.046 Vm/N for the hydrostatic g constant were observed. The material also showed no pressure hys...

R. Y. Ting

1985-01-01

325

A new generation of more pH stable reversed phases prepared by silanization of zirconized silica.  

PubMed

To further extend our studies in the search for reversed phases with enhanced durability at high pH, zirconized silica has now been explored as an alternative support. The synthesis of the new stationary phases involves silanization of a zirconium-modified silica support with a C(18) trifunctional silane, followed by endcapping. The chromatographic properties of the C(18) phases based on zirconized silica are similar to their titanized silica counterparts. Accelerated high pH stability tests, using phosphate mobile phases and elevated temperature, have shown that the zirconized silica phases have promising advantages not only over similarly prepared non-metalized phases but also over titanized silica C(18) phases. PMID:18243228

Silva, César R; Airoldi, Claudio; Collins, Kenneth E; Collins, Carol H

2008-05-16

326

Zircon and granite petrology  

Microsoft Academic Search

The typologic study of zircon populations from granitic rocks lead to the proposition of a genetic classification with three main divisions: (1) granites of crustal or mainly crustal origin [(sub) autochthonous and aluminous granites)]; (2) granites of crustal+mantle origin, hybrid granites (calc-alkaline and sub-alkaline series granites); (3) granites of mantle or mainly mantle origin (alkaline and tholeiitic series granites). In

J. P. Pupin

1980-01-01

327

Tides in Titan  

NASA Technical Reports Server (NTRS)

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

Rappaport, Nicole J.

1997-01-01

328

Future Titan Mission Studies  

Microsoft Academic Search

Exploration of Titan will remain a solar system science priority even (or especially) after Cassini. Not only does Titan offer an array of meteorological, oceanographical and geological phenomena richer than anywhere except Earth, but Titan's importance as an astrobiological target with a rich organic inventory has been long recognized. In-situ surface chemistry studies, meteorological and seismological monitoring and high-resolution geomorphological

R. Kakuda; T. Spilker; K. Baines; R. Lorenz

2002-01-01

329

Does Titan have oceans?  

NASA Astrophysics Data System (ADS)

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

Lunine, J. I.

1994-04-01

330

Titan Haze  

NASA Technical Reports Server (NTRS)

The Titan haze exerts a dominating influence on surface visibility and atmospheric radiative heating at optical and near-infrared wavelengths and our desire to understand surface composition and atmospheric dynamics provides a strong motivation to study the properties of the haze. Prior to the Cassini/Huygens missions the haze was known to be global in extent, with a hemispheric contrast asymmetry, with a complicated structure in the polar vortex region poleward of about 55 deg latitude, and with a distinct layer near 370 km altitude outside of the polar vortex at the time of the Voyager 2 flyby. The haze particles measured by the Pioneer and Voyager spacecraft were both highly polarizing and strongly forward scattering, a combination that seems to require an aggregation of small (several tens of nm radius) primary particles. These same properties were seen in the Cassini orbiter and Huygens Probe data. The most extensive set of optical measurements were made inside the atmosphere by the Descent Imager/Spectral Radiometer (DISR) instrument on the Huygens Probe. At the probe location as determined by the DISR measurements the average haze particle contained about 3000 primary particles whose radius is about 40 nm. Three distinct vertical regions were seen in the DISR data with differing particle properties. Refractive indices of the particles in the main haze layer resemble those reported by Khare et al. between O.3S and about 0.7 micron but are more absorbing than the Khare et al. results between 0.7 micron and the long-wavelength limit of the DISR spectra at 1.6 micron. These and other results are described by Tomasko et al., and a broader summary of results was given by Tomasko and West,. New data continue to stream in from the Cassini spacecraft. New data analyses and new laboratory and model results continue to move the field forward. Titan's 'detached' haze layer suffered a dramatic drop in altitude near equinox in 2009 with implications for the circulation and seasonal change in the stratosphere. The book chapter associated with this talk will also present new material on thermal-infrared data analysis and on new developments in laboratory work and haze microphysical modeling.

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

2011-01-01

331

Near electrode fatigue in lead zirconate titanate ceramics  

Microsoft Academic Search

Fatigue in ferroelectric materials is partly due to a complex interplay of ferroelectric ceramic and electrode material. Different types of silver electrodes were tested for their effect on fatigue. Material damage mostly occurs in the near-electrode volume. Removal of material to different depths from the electrode yields different degrees of recovery of device properties depending on electrode material and cycle

Y. Zhang; D. C. Lupascu; N. Balke; J. Rödel

2005-01-01

332

Mechanism of electric fatigue crack growth in lead zirconate titanate  

Microsoft Academic Search

A series of experiments was performed with through-thickness cracks in ferroelectric double cantilever beam (DCB) specimens. Cyclic electric fields of different amplitudes were applied which resulted in cyclic crack propagation perpendicular to the electric field direction. Crack propagation was observed optically and three regimes were identified: a pop-in from a notch, steady-state crack growth and a decrease of the crack

Ilona Westram; William S. Oates; Doru C. Lupascu; Jürgen Rödel; Christopher S. Lynch

2007-01-01

333

Measured displacement energies of oxygen ions in titanates and zirconates  

Microsoft Academic Search

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

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

2003-01-01

334

Impedance spectroscopy study of strontium modified lead zirconate titanate ceramics  

NASA Astrophysics Data System (ADS)

(Pb0.97Sr0.03)(Zr0.05Ti0.95)O3 nanocrystalline powder was prepared by a solution based chemical method. Preliminary x-ray diffractogram analysis of some aspects of crystal structure showed that a single-phase compound was formed exhibiting a tetragonal system. Impedance spectroscopy study showed the presence of both bulk and grain boundary effects in the material, which is also evident from the scanning electron microscope micrographs. The bulk conductivity indicates an Arrhenius-type thermally activated process. The ac conductivity spectrum obeyed the Jonscher power law. Modulus analysis indicated the possibility of hopping mechanism for electrical processes in the system with a nonexponential type of conductivity relaxation.

Sen, Shrabanee; Choudhary, R. N. P.; Tarafdar, Abhijit; Pramanik, P.

2006-06-01

335

Evolution of Rayleigh constant in fatigued lead zirconate titanate capacitors  

NASA Astrophysics Data System (ADS)

The capacitance of Pt/PbZr0.5Ti0.5O3/Pt capacitors versus the strength of applied ac electric field E has been measured for samples that fatigued at different square pulse switching cycles. Based on the in-series capacitor model, the variation of interface capacitance and bulk ferroelectric capacitance at different stages of fatigue were treated separately. A simplified method was derived to calculate the initial dielectric constant and Rayleigh constant for the bulk ferroelectric film from the ac electric field dependence of the sample capacitance. It was found that the initial dielectric constant and Rayleigh constant for the bulk ferroelectric film changed a little when the number of cycles is less than 3×106, whereas it decreased remarkably when the number of cycles is greater than 3×106. The suppression of polarization was attributed to pinning of the domain walls at the electrode/ferroelectric interface.

Sun, J. L.; Chen, J.; Meng, X. J.; Yu, J.; Bo, L. X.; Guo, S. L.; Chu, J. H.

2002-05-01

336

Interior of Titan  

NASA Technical Reports Server (NTRS)

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

Stevenson, David J.

1992-01-01

337

Origin of Titan's Atmosphere  

NASA Astrophysics Data System (ADS)

Titan has remarkable features - a dense N2 atmosphere and hydrological cycles of CH4 - that are resemble to those of Earth. How did the atmosphere develop on Titan? Was its origin similar to that of Earth’s atmosphere? Although these questions remain unsolved, the Cassini-Huygens mission has provided important clues to understand the origin of Titan’s atmosphere. 1) The low abundance of primordial Ar indicates that Titan’s N2 would have been delivered in less volatile form, probably as NH3. 2) Titan’s interior may have been only partially differentiated or may consist of low-density rock materials, suggesting that the interior would have been cooler than previously thought. 3) Observations of Enceladus’ plume suggest that the chemical composition of building materials of the Saturnian satellites would have been similar to that of comets; i.e., CO2 would have been more abundant than CH4 in the satellitesimals. 4) Relatively young surface age, high levels of radiogenic Ar, and the absence of global CH4 oceans suggest recent degassing of CH4 from the interior. The observations 1) and 2) imply the importance of conversion process of NH3 to N2 on Titan while maintaining the interior cool. However, because all of proposed mechanisms converting NH3 to N2 (e.g., photolysis, shock heating, and impact) also dissociate primordial CO2 to CO, the lack of abundant CO in the present atmosphere is a big issue. Furthermore, if Titan’s interior is undifferentiated, this is apparently inconsistent with a view of young surface and recent degassing. So far, there is no model which explains the above observations consistently. In this paper, we review the proposed mechanisms to create a N2-CH4 atmosphere on Titan and discuss new problems raised by Cassini. Then, we will discuss a plausible history of Titan’s atmosphere on the basis of the new observations.

Sekine, Yasuhito

2012-04-01

338

Genetic Adaptive Control for PZT Actuators  

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

339

Etching fission tracks in zircons  

USGS Publications Warehouse

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.

Naeser, C. W.

1969-01-01

340

Si diffusion in zircon  

NASA Astrophysics Data System (ADS)

Self-diffusion of Si under anhydrous conditions at 1 atm has been measured in natural zircon. The source of diffusant for experiments was a mixture of ZrO2 and 30Si-enriched SiO2 in 1:1 molar proportions; experiments were run in crimped Pt capsules in 1-atm furnaces. 30Si profiles were measured with both Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis with the resonant nuclear reaction 30Si(p,?)31P. For Si diffusion normal to c over the temperature range 1,350-1,550°C, we obtain an Arrhenius relation D = 5.8 exp(-702 ± 54 kJ mol-1/ RT) m2 s-1 for the NRA measurements, which agrees within uncertainty with an Arrhenius relation determined from the RBS measurements [62 exp(-738 ± 61 kJ mol-1/ RT) m2 s-1]. Diffusion of Si parallel to c appears slightly faster, but agrees within experimental uncertainty at most temperatures with diffusivities for Si normal to c. Diffusion of Si in zircon is similar to that of Ti, but about an order of magnitude faster than diffusion of Hf and two orders of magnitude faster than diffusion of U and Th. Si diffusion is, however, many orders of magnitude slower than oxygen diffusion under both dry and hydrothermal conditions, with the difference increasing with decreasing temperature because of the larger activation energy for Si diffusion. If we consider Hf as a proxy for Zr, given its similar charge and size, we can rank the diffusivities of the major constituents in zircon as follows: D Zr < D Si << D O, dry < D O, ‘wet’.

Cherniak, D. J.

2008-05-01

341

Charge trapping centers in ferroelectric ceramics.  

National Technical Information Service (NTIS)

Electron paramagnetic resonance (EPR), photo-thermal deflection spectroscopy (PDS), and electrical measurements were used to characterize as-received and UV-lluminated lead lanthanum zirconate titanate (PLZT) and PZT ceramics. Following optical illuminati...

C. H. Seager W. L. Warren B. A. Tuttle R. D. Nasby D. Dimos

1992-01-01

342

Sensitivity of Micro Cantilever Mass Sensor Transduced by PZT Film  

Microsoft Academic Search

Piezoelectric thin film transduced micro resonator offers competitive potential applications in mass sensing technology because of its low driving-voltage, self-actuation self-sensation capability and better impedance-matching with electronics. In this paper, the authors fabricated PZT cantilevers with different geometries and PZT thicknesses. Then the authors investigated the essential aspects of the PZT cantilever for mass-detection sensitivity from the viewpoint of mechanical

Jian Lu; Tsuyoshi Ikehara; Mitsuo Konno; Ryutaro Maeda; Takashi Mihara

2007-01-01

343

Fabrication and properties of microcantilever using piezoelectric PZT thin films  

Microsoft Academic Search

Piezoelectrically driven micro-cantilevers using Pb(Zr0.52, Ti0.48)O3 (PZT) films have been successfully fabricated. We have fabricated the micro-cantilever for the nano-storage or AFM. The cantilever structures consist of piezoelectric PZT capacitors fabricated on a low stress SiNx supporting layer. Flat micro-cantilevers have been obtained by controlling the stress in Pt electrode and PZT layer. The dielectric constant and loss of the

Jungryul Ahn; Dongwoo Kim; Geunyoung Yeom; Jibeom Yoo; Jaichan Lee

2001-01-01

344

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

NASA Astrophysics Data System (ADS)

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

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

2008-07-01

345

Response of a pentagonal PZT element as a component of a 4? real-time detector  

NASA Astrophysics Data System (ADS)

A shell-structured detector has been proposed to monitor tiny space debris dust in real time This form was aimed at detecting hypervelocity particles free from the incident direction The simplest structure was accomplished in a dodecahedron that comprised twelve pentagonal elements each of which was fabricated from piezoelectric lead-zirconane-titanate PZT The pentagonal element was 9 cm 2 area and 1mm thick On the surface one pentagonal electrode and five narrow electrodes were coated at the central region and at the edges respectively The response of the pentagonal element was studied using hypervelocity iron particles in the velocity range from 4 to 7 km s The results were in the following 1 The response curve was similar to that by a small circular-type element 1 2 The amplitude immediately after collision showed a linear relation with the momentum at collision 2 The coordinate at collision was uniquely determined to measure the propagation time by arranging the narrow electrodes 3 When the pentagonal electrode was divided into segments the phase of output signal was interesting It appeared opposite between the hit and the missed segments A preamplifier to match elements of high capacitance was discussed In summary the characteristics of the pentagonal PZT elements were studied for a 4 pi debris dust detector The output amplitude was proportional to the momentum of the impact particle in this velocity range 1 T Miyachi et al Adv Space Res 35 2005 1263 2 T Miyachi et al J Appl Phys

Miyachi, T.; Fujii, M.; Kuraza, G.; Iwaii, T.; Ohashi, H.; Shibata, H.; Onishi, T.; Gruen, E.; Srama, R.; Okada, N.

346

Zircon growth in shear zones  

NASA Astrophysics Data System (ADS)

The possibility of direct dating of the deformation process is critical for understanding of orogenic belts evolution. Establishing the age of deformation by isotopic methods is indispensable in the case of uneven deformation overlapping, when later deformation inherits the structural plan of the early strains, and to distinguish them on the basis of the structural data only is impossible. A good example of zircon from the shear zones is zircon formed under the eclogite facies conditions. On the one hand, the composition of zircon speaks about its formation simultaneously to eclogitic paragenesis (Rubatto, Herman, 1999; Rubatto et al., 2003). On the other hand, geological studies show that mineral reactions of eclogitization are often held only in areas of shear deformations, which provides access of fluid to the rocks (Austrheim, 1987; Jamtveit et al., 2000; Bingen et al., 2004). Zircons from mafic and ultramafic rocks of the Tanaelv and Kolvitsa belts (Kola Peninsula, the Baltic Shield) have showed that the metamorphic zircon growth is probably controlled by the metamorphic fluid regime, as evidenced by an increase of zircon quantity with the degree of shearing. The internal structure of zircon crystals can provide an evidence of zircon growth synchronous with shearing. The studied crystals have a sector zoning and often specific "patchy" zoning (Fig. 1), which speaks about rapid change of growth conditions. Such internal structure can be compared with the "snowball" garnet structure reflecting the rotation of crystals during their growth under a shift. Rapidly changing crystallization conditions can also be associated with a small amount of fluid, where supersaturation is changing even at a constant temperature. Thus, the growth of metamorphic zircon in shear zones is more likely to occur in the fluid flow synchronous with deformation. A distinctive feature of zircons in these conditions is isometric shape and sector "patchy" zoning. The work was supported by Russian Foundation of Basic Research (project: 13-05-00035.) and the DES-6 program.

Kaulina, Tatiana

2013-04-01

347

Future Exploration of Titan  

NASA Astrophysics Data System (ADS)

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

Lorenz, R. D.; Titan Decadal Panel Collaboration

2001-11-01

348

Application of the sol-gel method to deposition of thin films  

Microsoft Academic Search

A method for synthesizing ferroelectric thin films of lead zirconate-titanate (PZT) and lead-lan- thanum zirconate-titanate (PLZT) by a modified sol-gel technique is reported. The following chemical compositions with the Zr\\/Ti ratio were obtained: PZT 65\\/35 and PLZT 6.5\\/65\\/35. Thin films, prepared from acetate and alkoxide precursors of La, Pb, Zr and Ti, were deposited on stainless steel and MgO substrates

ALDONA ZARYCKA; JAN ILCZUK; DIONIZY CZEKAJ

349

Zircons from the Stannern Eucrite  

NASA Astrophysics Data System (ADS)

Zircons are becoming increasingly apparent in meteorites of the howardite-eucrite-diogenite association. The zircons generally occur as small (<=30 micrometers) inclusions closely associated with ilmenite and chromite. We have previously analyzed zircons from eucritic enclaves from Vaca Muerta [1], zircons from the brecciated eucrite Padvarninkai [2], and from the Yamato 791438 eucrite [3]. Here we report on our continued studies of meteoritic zircons with ion probe U-Th-Pb isotopic systematics and REE abundances of zircons from the Stannern eucrite. Eighteen zircons were identified and analyzed by electron probe in a polished section of the Stannern eucrite. An average composition is SiO2 31.78, TiO2 0.73, FeO 1.45, ZrO2 64.26, HfO2 1.04, total 99.26. The mean Zr/Hf ratio of 63 (range 21-129) is similar to the range observed in lunar zircons 30-60. Most of these zircons were not suitable for analysis (too small, proximity to cracks) and only four were analyzed for U-Th-Pb isotopes and trace-element abundances with the SHRIMP ion microprobe. All of these zircons occur in close association with ilmenite. The ilmenite grains range in size up to several hundred micrometers, but the zircons are at most only 20 micrometers in diameter. The analytical techniques for ion microprobe analysis are described in [1]. The U concentrations ranged from 30-80 ppm and the mean ^207Pb/^206Pb age of the four grains is 4550 +- 10 Ma (2 sigma); these values are very similar to the range in U concentrations (30-60 ppm) and the age (4553 +- 13 Ma) of the zircons analyzed from Padvarninkai [2]. The zircon age is compatible with the Sm-Nd age of Stannern (4.48 +- 0.07 Ga [4]) and the zircons have not been affected by the event(s) that disturbed the Rb-Sr system (3.1 +- 0.5 Ga [5]). The REE patterns (Fig. 1) are also very similar to the range shown in Padvarninkai. The LREE patterns are flat but the absolute abundances are different in the four grains ranging from chondritic to over 100 x chondritic. Europium is depleted in all zircons relative to the trend of the other REE. The HREE abundances are smoothly fractionated with overall absolute abundances that vary sympathetically with the overall LREE abundances. The similarity of the REE in zircons from Padvarninkai is noteworthy since the absolute abundances of REE in Stannern are 20 x CI compared with 10 x CI in Padvarninka. Therefore the zircon compositions do not appear to be controlled solely by the total REE inventory. References: [1] Ireland and Wlotzka (1992) EPSL 109, 1. [2] Bukovanska et al. (1991) Meteoritics 26, 325. [3] Ireland et al. (1992) Lunar Planet. Sci. XXIII, 569. [5] Birck and Allegre (1978) EPSL 39, 37. Figure 1, which in the hard copy appears here, shows Stannern REE.

Ireland, T. R.; Bukovanska, M.

1992-07-01

350

MEMS-based thick film PZT vibrational energy harvester  

Microsoft Academic Search

We present a MEMS-based unimorph silicon\\/PZT thick film vibrational energy harvester with an integrated proof mass. We have developed a process that allows fabrication of high performance silicon based energy harvesters with a yield higher than 90%. The process comprises a KOH etch using a mechanical front side protection of an SOI wafer with screen printed PZT thick film. The

A. Lei; R. Xu; A. Thyssen; A. C. Stoot; T. L. Christiansen; K. Hansen; R. Lou-Moller; E. V. Thomsen; K. Birkelund

2011-01-01

351

Embedded PZT Wafer Sensors for Structural Health Monitoring  

Microsoft Academic Search

Recent advances in structural integrity evaluation have led to the development of PZT wafer sensors (PWAS) which can be embedded or surface mounted for both acoustic emission (AE) and ultrasonic (UT) modes, which forms an integrated approach for Structural Health Monitoring (SHM) of aerospace structures. For the fabrication of PWAS wafers, soft PZT formulation (SP-5H Grade containing dopants like BA,

R. Gangadharan; C. R. L. Murthy; M. R. Bhat; A. Sen; N. Das; A. Seal

2007-01-01

352

Crystal Structure and Dielectric Properties of PZT Ferroelectric Ceramic Fibers  

Microsoft Academic Search

The crystal structures of PZT ceramic fibers with continuum spinning process were identified, showing a pure tetragonal phase of perovskite for the samples treated at around 900°C. The microstructures of the PZT fibers were observed, displaying relatively complex evolution with the increasing of temperature during heat treatment. With the increasing of frequency, the dielectric constants and loss tangents became smaller

Z. X. Xiong; J. Pan; H. Xue; M. F. Mai; H. Qiu; L. F. Chen

2010-01-01

353

The astrobiology of Titan  

Microsoft Academic Search

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

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

2006-01-01

354

Titan: Callisto With Weather?  

Microsoft Academic Search

Instead of being endogenically active, Titan's interior may be cold and dead. Those landforms on Titan that are unambiguously identifiable can all be explained by exogenic processes (aeolian, fluvial, impact cratering, and mass wasting). At the scale of available imaging data, the surface is dominated by vast dune ergs and by fluvial erosion, transportation, and deposition. The sparse distribution of

J. M. Moore; R. T. Pappalardo

2008-01-01

355

Titan: an exogenic world?  

Microsoft Academic Search

Titan's may be a world whose landscape is shaped by exogenic processes, with a relatively inactive interior and minor or negligible endogenic activity. Those landforms on Titan that are unambiguously identifiable can all be explained by exogenic processes (aeolian, fluvial, impact cratering, and mass wasting). Previous suggestions of endogenically produced cryovolcanic constructs and flows have been, without exception, lack conclusive

Jeffrey M. Moore; Robert T. Pappalardo; Alan D. Howard; Paul M. Schenk

2010-01-01

356

Titan Airship Explorer  

Microsoft Academic Search

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

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

2002-01-01

357

Clash of the Titans  

ERIC Educational Resources Information Center

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,"…

Subramaniam, Karthigeyan

2010-01-01

358

Neutron Scattering Study of Single Crystal PZT  

NASA Astrophysics Data System (ADS)

Single crystal specimens of the technologically important ferroelectric material Pb(Zr1-xTix)O3, or PZT, have only recently been grown for the first time at Simon Fraser University. We have characterized the transition temperatures, thermal expansion, and crystal structure of a PZT single crystal between 10 K and 670 K using neutron scattering methods. This crystal, which has a composition (x˜0.46) that lies close to the morphotropic phase boundary (MPB), exhibits a surprisingly large thermal expansion (˜ 10-3 1/K) that changes sign near 545 K, and a rhombohedral crystal structure at 30 K. In addition we observe an enormous relief of extinction beginning around 650 K, which was observed through the temperature dependence of the (200) Bragg peak. Neutron inelastic measurements are planned as are measurements under an applied electric field. This work was supported by the U. S. Office of Naval Research (Grant No. N00014-1-06-0166). All neutron measurements were performed at the NIST Center for Neutron Research.

Phelan, Daniel; Gehring, Peter; Ye, Zuo-Guang; Long, Xifa

2010-03-01

359

Water-based technique to produce porous PZT materials  

NASA Astrophysics Data System (ADS)

Water based colloidal processing of PZT materials was investigated in order to reduce costs and employ more environmental friendly manufacturing. The technique addressed was the production of porous thick samples by the so called “starch consolidation”. PZT “soft” compositions were used. The “starch consolidation” process allows to obtain the green body by raising the temperature of a suspension of PZT powder, soluble starch and water, cast into a metal mould. The influence of the processing parameters and composition on the morphology, pore volumes, pore size distributions and piezoelectric properties are investigated. Zeta potential determination and titration with different deflocculants were essential tools to adjust the slurry formulation.

Galassi, C.; Capiani, C.; Craciun, F.; Roncari, E.

2005-09-01

360

Titan's organic chemistry  

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

361

Functionalization of layered titanates.  

PubMed

This review article describes the synthesis, modification, and function of lepidocrocite-type layered titanate (A(x)Ti(2-y)M(y)O4, A: A, interlayer cation; M, metal or vacancy). Due to the compositional variation, which affects cation exchange, semiconducting and swelling properties, lepidocrocite-type layered titanates have attracted increasing attention in solid-state materials chemistry. The immobilization of functional units has been done to improve the properties as well as to impart additional functions. Here, we highlight recent developments of hybrid materials derived from the intercalation of inorganic and organic cations, organic functional groups, and nanoparticles into lepidocrocite-type layered titanates. PMID:24745207

Ide, Yusuke; Sadakane, Masahiro; Sano, Tsuneji; Ogawa, Makoto

2014-03-01

362

Surface-modified lead-zirconium-titanate system for solution-processed ferroelectric-gate thin-film transistors  

NASA Astrophysics Data System (ADS)

We propose the use of a La2O3 (LO) film as the capping layer for improvement of a semiconductor/insulator interface in a solution-processed indium-tin-oxide (ITO) ferroelectric-gate thin-film transistor (FGT) device. It is demonstrated that the LO layer acts as a good barrier film not only for preventing the interdiffusion between the ITO semiconductor and lead-zirconium-titanate (PZT) insulator layers, but also for stabilizing the PZT surface structure. The fabricated FGT device exhibited high I on/ I off, large M w, high ? FE and improved retention time of about 109, 3.5 V, 7.94 cm2 V-1 s-1 and 1 day, respectively, which are comparable to or better than those obtained with FGTs fabricated by means of conventional vacuum processes. We also point out that the key origin of the interface improvement is likely due to the incorporation of La into the PZT system, forming a La surface-modified PZT system which is more stable than the pure PZT in terms of Pb volatility and formation of oxygen vacancies.

Phan, Tue Trong; Miyasako, Takaaki; Higashimine, Koichi; Tokumitsu, Eisuke; Shimoda, Tatsuya

2013-11-01

363

Titan's "Hot Cross Bun": A Titan Laccolith?  

NASA Astrophysics Data System (ADS)

Cassini’s RADAR instrument acquired Synthetic Aperture Radar data during the T83 flyby on May 22, 2012. The data showed a feature centered at 38.5N, 203W that resembles a “hot cross bun”. This type of feature has not been seen on Titan before, even though 52% of Titan’s surface has been imaged using SAR. The feature, approximately 100 km across, is mostly radar bright but the cross pattern, interpreted to be extensional fractures, located roughly at the center of the brighter area, appears darker at radar wavelengths (2.3 cm). Radar illumination of the image indicates that the fractures are lower in elevation than the surrounding bright region. The morphology of the region is markedly similar to that of a 30-km dome-shaped feature on Venus that lies at the summit of the Kunapipi volcano. The Venus feature is interpreted to be the result of intrusion of magma at the summit of the volcano [1]. A similar feature, interpreted as a laccolith, is seen on the Moon near the crater Ramsden [2]. The lunar feature, imaged by the Lunar Reconnaissance Orbiter, shows the cross-shaped depression over a 300 m high rise. No topographic data for the feature on Titan are available at this time, but the morphology seen by the SAR data suggests that the feature may have been formed by material pushing up from below. Laccoliths form when an igneous intrusion splits apart two strata, resulting in a domeline structure. This previously unknown type of structure on Titan may be yet another indication of cryovolcanism. [1] Stofan, E.R., et al, Icarus, 152, 75-95, 2001. [2] Wichman, R.W. and Schultz, P. H. (1996). Icarus, 122, Issue 1, July 1996, pages 193-199. doi:10.1006/icar.1996.0118

Lopes, Rosaly M. C.; Stofan, E. R.; Wall, S. D.; Wood, C.; Kirk, R. L.; Lucas, A.; Mitchell, K. L.; Lunine, J. I.; Turtle, E. P.; Radebaugh, J.; Malaska, M.; Cassini RADAR Team

2012-10-01

364

Li isotopes in archean zircons  

NASA Astrophysics Data System (ADS)

Li is a fluid mobile, moderately incompatible element with a large mass difference between its two stable isotopes. Different processes can fractionate 7Li/6Li (fluid-rock interaction, metamorphic reactions, and Li diffusion), leading to variation by over 50‰ of ?7Li for common crustal material. These large variations make ?7Li a potential tracer of continental weathering and of the fluids affecting magma sources. Here, we report ?7Li and trace elements in Archean igneous zircons from TTG and sanukitoid granitoids from the Superior Province (Canada) in order to characterize Li in Archean zircons from well-described samples. These data are compared to detrital zircons from the Jack Hills (Western Australia) for which parent rock-type is uncertain. This study aims to better understand Li substitution in zircon and to evaluate the utility of ?7Li and [Li] for Archean petrogenesis. Zircons (n=71) were analyzed for ?7Li and trace elements (Li, P, Ca, Ti, V, Fe, Y, REE, U, Th) using an IMS-1280 ion microprobe. Most of the zircons display typical igneous REE patterns and zoning by CL. [Li] averages 13.1 ± 9 for TTG, 25.7 ± 19 for Sanukitoid and 31.0 ± 14 ppm for Jack Hills zircons, which are distinct from mantle-related zircons (<0.1 ppm). Values of ?7Li average 1.0 ± 4.5‰ for TTGs, 6.3 ± 4.4‰ for sanukitoids and -2.6 ± 8.8‰ for Jack Hills samples. Trace elements were analyzed from single spots in order to evaluate coupled substitutions. Atomic ratios (3Li+Y+REE)/P average 2.6, showing that Li and trivalent atoms are not charge-balanced by P, and suggesting that Li does not replace Zr, according to the xenotime substitution. However, (Y+REE)/(Li+P) atomic ratios average 1.0 ± 0.6, supporting the hypothesis that Li is interstitial and partly compensates trivalent cations. Several observations in this study suggest that [Li] is primary in the studied zircons: i) if Li is interstitial, charge-balance and slow diffusion of REE would control Li mobility, ii) core-rim or oscillatory zoning is observed for [Li] in many high T zircons, iii) CL zoning and low Ca+Fe, U+Th and U/Th imply little radiation damage. Values of ?7Li become erratic at [Li] < ~5 ppm and low values are not interpreted. We suggest that small amounts of non-ionic substitution could be significant for small [Li], whereas interstitial substitution dominates at > ~5 ppm. Li content and isotopic compositions of TTG zircons suggest genesis from mantle-like material, as suggested by ?18O(Zrc) (5.5 ± 0.4‰, King et al., 1998). Sanukitoids are commonly thought to be derived from the melting of peridotite metasomatized by seawater-like slab-dehydration fluids, (supported by the high ?7Li(Zrc)), followed by extensive fractional crystallization, explaining the high sanukitoid [Li]. [Li] and ?7Li thus reflect petrogenetic processes. The Jack Hills detrital zircons are consistent with crustal sources including TTG, sanukitoid and sediment-contaminated granitoid magmas.

Bouvier, A.; Ushikubo, T.; Kita, N.; Cavosie, A. J.; Kozdon, R.; Valley, J. W.

2009-12-01

365

Crystallization thermometers for zircon and rutile  

Microsoft Academic Search

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

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

2006-01-01

366

Titan Casts Revealing Shadow  

NASA Astrophysics Data System (ADS)

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,

2004-05-01

367

Microstructural development in solution derived PZT thin films  

SciTech Connect

In the fabrication of PZT films by solution deposition techniques, control of phase evolution, microstructure, ferroelectric domain assemblage, etc. is important. Electron microscopy was used to correlate microstructure with film processing parameters.

Headley, T.J.; Tuttle, B.A.; Voigt, J.A.; Michael, J.R.

1994-03-01

368

Microstructural development in solution derived PZT thin films.  

National Technical Information Service (NTIS)

In the fabrication of PZT films by solution deposition techniques, control of phase evolution, microstructure, ferroelectric domain assemblage, etc. is important. Electron microscopy was used to correlate microstructure with film processing parameters.

T. J. Headley B. A. Tuttle J. A. Voigt J. R. Michael

1994-01-01

369

Fabrication of Flexible Piezoelectric PZT/Fabric Composite  

PubMed Central

Flexible piezoelectric PZT/fabric composite material is pliable and tough in nature which is in a lack of traditional PZT patches. It has great application prospect in improving the sensitivity of sensor/actuator made by piezoelectric materials especially when they are used for curved surfaces or complicated conditions. In this paper, glass fiber cloth was adopted as carrier to grow PZT piezoelectric crystal particles by hydrothermal method, and the optimum conditions were studied. The results showed that the soft glass fiber cloth was an ideal kind of carrier. A large number of cubic-shaped PZT nanocrystallines grew firmly in the carrier with a dense and uniform distribution. The best hydrothermal condition was found to be pH 13, reaction time 24?h, and reaction temperature 200°C.

Chen, Caifeng; Hong, Daiwei; Wang, Andong; Ni, Chaoying

2013-01-01

370

Is Titan Partially Differentiated?  

NASA Astrophysics Data System (ADS)

The recent measurement of the gravity coefficients from the Radio Doppler data of the Cassini spacecraft has improved our knowledge of the interior structure of Titan (Rappaport et al. 2008 AGU, P21A-1343). The measured gravity field of Titan is dominated by near hydrostatic quadrupole components. We have used the measured gravitational coefficients, thermal models and the hydrostatic equilibrium theory to derive Titan's interior structure. The axial moment of inertia gives us an indication of the degree of the interior differentiation. The inferred axial moment of inertia, calculated using the quadrupole gravitational coefficients and the Radau-Darwin approximation, indicates that Titan is partially differentiated. If Titan is partially differentiated then the interior must avoid melting of the ice during its evolution. This suggests a relatively late formation of Titan to avoid the presence of short-lived radioisotopes (Al-26). This also suggests the onset of convection after accretion to efficiently remove the heat from the interior. The outer layer is likely composed mainly of water in solid phase. Thermal modeling indicates that water could be present also in liquid phase forming a subsurface ocean between an outer ice I shell and a high pressure ice layer. Acknowledgments: This work was conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

Mitri, G.; Pappalardo, R. T.; Stevenson, D. J.

2009-12-01

371

The oldest zircons in the solar system  

NASA Astrophysics Data System (ADS)

The occurrence, chemistry, and U-Th-Pb isotopic systematics of three meteoritic zircon assemblages, two from the Vaca Muerta mesosiderite and one from the Simmern H5 chondrite, are presented. Like terrestrial zircons, the meteoritic zircons are enriched in the heavy rare-earth elements, but unlike terrestrial zircons, they do not show a positive Ce anomaly. This feature is also absent in one lunar zircon analyzed and probably reflects the oxidation state of the formation environment: under oxidizing conditions Ce(4+) is stabilized, whereas under relatively reducing conditions Ce(3+) is stable. The zircon from Simmern has depletions in the relative abundances of Tm and Yb, a characteristic of the volatility fractionation of the REE. The Simmern zircon has an exceptionally low U concentration (around 180 ppb), and only a poorly constrained Pb-207/Pb-206 age of 4100 +/- 700 Ma could be obtained.

Ireland, T. R.; Wlotzka, F.

1992-03-01

372

Titan’s atmosphere from ISO mid-infrared spectroscopy  

Microsoft Academic Search

We have analyzed Titan observations performed by the Infrared Space Observatory (ISO) in the range 7–30 ?m. The spectra obtained by three of the instruments on board the mission (the short wavelength spectrometer, the photometer, and the camera) were combined to provide new and more precise thermal and compositional knowledge of Titan’s stratosphere. With the high spectral resolution achieved by

Athena Coustenis; A. Salama; B. Schulz; S. Ott; E. Lellouch; T. h Encrenaz; D. Gautier; H. Feuchtgruber

2003-01-01

373

Modified cofiring behaviors between PMN-PNN-PZT piezoelectric ceramics and PZT-doped 70Ag–30Pd alloy metallization  

Microsoft Academic Search

The cofiring behaviors between PMN-PNN-PZT piezoelectric ceramics and 70Ag–30Pd electrode paste were investigated in view of sintering densification behavior, thermal expansion coefficients (TEC) and interfacial physical integrity. The results showed that mismatched cofiring characteristics have greatly affected the reliability of multilayer piezoelectric ceramic devices. The application of a PZT additive to 70Ag–30Pd electrode technology has markedly improved the above-mentioned cofiring

Ruzhong Zuo; Longtu Li; Zhilun Gui

2002-01-01

374

Feasibility study of PZT thin-film sensors and actuators for smart microstructures and MEMS devices  

NASA Astrophysics Data System (ADS)

This paper demonstrates the feasibility of using PZT thin films as sensors and actuators for smart structures and MEMS applications. The feasibility study includes specimen preparation and vibration testing. The specimen consists of a substrate, a PZT thin film, and a bulk PZT. The substrate is a doped conductive silicon wafer. The PZT thin film is fabricated through sol-gel dip-coating process with added PZT nano-particles to prevent homogeneous crystallization. The thickness of the PZT thin film is about 5 micrometers and the capacitance varies from 90 to 130 pF. The bulk PZT, which is commercially available, serves as a reference sensor and actuator for the specimen. The dimensions of the specimen are 2.7 cmx 1.4 cm . 0.4 mm. The vibration testing consists of sensor testing and actuator testing. In the sensor testing, the PZT thin film serves as a sensor, while the bulk PZT serves as an actuator. The specimen is cantilevered, and harmonic excitations are generated from 500 Hz to 500 kHz. A laser Doppler vibrometer also monitors the specimen vibration in addition to the PZT thin-film sensor. As a sensor, the PZT thin film produces legible harmonic output voltage ranging from 0.5 mV to 200 mV. In the actuator testing, the PZT thin film serves as an actuator, while the bulk PZT serves as a sensor. Similarly, harmonic excitations are generated from 100 Hz to 1 MHz. Depending on the excitation frequency, actuation voltage of the PZT thin film ranging from 0.1V to 100 V results in legible voltage response form the bulk PZT. Also, the PZT thin film experiences significant aging when it serves as an actuator. This might result from fatigue or accumulated defects of the PZT thin film. Finally, the PZT thin film can become nonlinear in sensing and actuation, when the excitation voltage is too high.

Hsu, Yi-Chu; Shen, I. Y.; Cao, G. Z.

2002-07-01

375

The environment of Titan, 1975  

NASA Technical Reports Server (NTRS)

Information regarding the physical characteristics of Titan and atmospheric models necessary to support design and mission planning of spacecraft that are to orbit Titan, enter its atmosphere or land on its surface is given.

1976-01-01

376

Research on High Power Transducer Ceramics. Stress Sensitivity of Piezoelectric Ceramics: Part One: Sensitivity to Compressive Stress Parallel to the Polar Axis.  

National Technical Information Service (NTIS)

Measurements of changes in permittivity, tan delta and D33 as function of compressive stress parallel to the polar axis are presented for lead zirconate-lead titanate transducer ceramics. The hard ceramics (PZT-4 and PZT-8) suitable for high power applica...

H. H. A. Krueger

1967-01-01

377

Multiferroic properties of Pb(Zr,Ti)O3\\/CoFe2O4 composite thin films  

Microsoft Academic Search

In the present work we report multiferroic behavior in lead zirconate titanate (PZT)-cobalt iron oxide (CFO) composite thin films. It is found that upon annealing, the multilayered structures are intermixed at least partially, and CFO is phase separated into PZT matrix to form a composite film. The phase separation behavior has been characterized by x-ray photoelectron spectroscopy depth profiling of

N. Ortega; P. Bhattacharya; R. S. Katiyar; P. Dutta; A. Manivannan; M. S. Seehra; I. Takeuchi; S. B. Majumder

2006-01-01

378

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

Microsoft Academic Search

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

Leslie J. Bowen; Kenneth W. French

1992-01-01

379

Properties of Lead-Free Piezoceramics Based on Alkali Niobates  

Microsoft Academic Search

The market for piezoceramic components is dominated by lead zirconate titanate (PZT) materials containing more than 60 wt% lead. Since lead is a toxic heavy metal, it has become a great concern how to eliminate the use of PZT by replacing it by non-harmful materials while maintaining comparable piezoelectric properties. This was the objective of the European LEAF project within

Erling Ringgaard; Thom Wurlitzer; Wanda W. Wolny

2005-01-01

380

COLD SPRAY ELECTRODING OF PIEZOELECTRIC CERAMIC  

Microsoft Academic Search

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

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

381

True Young modulus of Pb(Zr,Ti)O3 films measured by nanoindentation  

Microsoft Academic Search

In order to assess transverse elastic modulus of lead zirconate titanate (PZT) thin films, we used a nanoindenter with constant monitoring of the force. It is shown that the true elastic modulus, i.e., the low pressure elastic modulus, can be measured by this method. This permitted a determination that sputter deposited PZT (54\\/46) films display a Young modulus close to

P. Delobelle; O. Guillon; E. Fribourg-Blanc; C. Soyer; E. Cattan; D. Rèmiens

2004-01-01

382

Nonlinear behavior of piezoceramics and piezocomposites under various ac fields  

Microsoft Academic Search

A study is carried out to compare the nonlinear behavior of piezoceramics and piezocomposites. The complex material parameters including losses were determined by model fittings. An experimental system has been used to investigate the ac electric field dependence of the properties of the transducer materials, including lead zirconate titanate (PZT) and PZT\\/epoxy 1–3 composite rings. An analysis of the changes

C. P. Chong; W. P. Chen; H. L. W. Chan; P. C. K. Liu

2004-01-01

383

Titan at the edge: 1. Titan's interaction with Saturn's magnetosphere in the prenoon sector  

Microsoft Academic Search

Titan's environment is variable when Saturn's magnetopause is not stationaryIrregular flows in Saturn's boundary layer modify Titan's induced magnetosphereTitan's ion tail may prevent the magnetopause from crossing Titan

D. Snowden; R. Winglee; A. Kidder

2011-01-01

384

Comparative studies of the transient response for PECP, MSCP, Barium Titanate, magneto-electro-elastic finite cylindrical shell under constant internal pressure using finite element method  

Microsoft Academic Search

Transient response for (PZT)-epoxy mixed component (PECP), (Terfenol-D)-epoxy mixed components (MSCP), Barium Titanate (BaTiO3) and magneto-electro-elastic (MEE) cylindrical shell is evaluated by developing the semi-analytical finite element model using the constitutive equations of the piezomagnetic medium employing the fourth-order Runge–Kutta method. Numerical results are presented and compared for the above materials under different clamped boundary conditions. A comparison between the

Atul Daga; N. Ganesan; K. Shankar

2008-01-01

385

The tides of Titan.  

PubMed

We have detected in Cassini spacecraft data the signature of the periodic tidal stresses within Titan, driven by the eccentricity (e = 0.028) of its 16-day orbit around Saturn. Precise measurements of the acceleration of Cassini during six close flybys between 2006 and 2011 have revealed that Titan responds to the variable tidal field exerted by Saturn with periodic changes of its quadrupole gravity, at about 4% of the static value. Two independent determinations of the corresponding degree-2 Love number yield k(2) = 0.589 ± 0.150 and k(2) = 0.637 ± 0.224 (2?). Such a large response to the tidal field requires that Titan's interior be deformable over time scales of the orbital period, in a way that is consistent with a global ocean at depth. PMID:22745254

Iess, Luciano; Jacobson, Robert A; Ducci, Marco; Stevenson, David J; Lunine, Jonathan I; Armstrong, John W; Asmar, Sami W; Racioppa, Paolo; Rappaport, Nicole J; Tortora, Paolo

2012-07-27

386

Titan's Winter Polar Vortex  

NASA Technical Reports Server (NTRS)

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.

Flasar, F.M.; Achterberg, R.K.; Schinder, P.J.

2008-01-01

387

Aboard the Titanic  

NSDL National Science Digital Library

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

Maahs, Mrs.

2010-04-20

388

Work of PZT ceramics sounder for sound source artificial larynx  

NASA Astrophysics Data System (ADS)

We aim to develop the easy-to-use artificial larynx with high tone quality. We focus on using a PZT ceramics sounder as its sound source, because it is small size, low power consumption, and harmless to humans. But conventional PZT ceramics sounder have the problem that it cannot generate an enough sound in the low frequency range, thus they cannot be used for artificial larynx. Then, we aim to develop the PZT ceramics sounder which can generate enough volume in the low frequency range. If we can lower the resonance frequency of the sounder, it can generate low pitch sound easily. Therefore I created the new diaphragm with low resonance frequency. In addition, we could obtain the high amplitude by changing method of driving. This time, we report on the characteristic comparison of this new PZT ceramics sounder and conventional one. Furthermore, for this new one, we analyzed the best alignment of PZT ceramics and the shape of the diaphragm to obtain low resonance frequency and big amplitude. In fact we analyzed the optimization of the structure. The analysis is done by computer simulation of ANSYS and Laser Doppler Vibrometer. In the future, we will add intonation to the generated sound by input wave form which is developed concurrently, and implant the sounder inside of the body by the method of fixing metal to biomolecule which is done too. And so high tone quality and convenient artificial larynx will be completed.

Sugio, Yuuichi; Kanetake, Ryota; Tanaka, Akimitsu; Ooe, Katsutoshi

2007-03-01

389

Inelastic neutron scattering from zircon  

SciTech Connect

A lattice dynamical investigation of zircon (ZrSiO{sub 4}) has been carried out to obtain a microscopic understanding of its thermodynamic properties, as well as to examine possible soft modes that may contribute to the phase transformation to scheelite type under high pressure. We have measured the neutron weighted phonon density of states of zircon from a polycrystalline sample. The neutron spectra reveal one-phonon excitations extending to 1130 cm{sup -1}, with phonon bands centered at 226, 298, 363, 540, 661, 726, 945, and 1081 cm{sup -1}. A quantitative analysis of the neutron results was carried out using a lattice dynamical rigid-ion model. 4 refs., 3 figs.

Nipko, J.C.; Loong, C.K.

1997-07-14

390

Wafer-Level Transfer Technologies for PZT-Based RF MEMS Switches  

Microsoft Academic Search

We report on wafer-level transfer technologies to integrate PZT-based radio frequency (RF) microelectromechanical-systems switches on CMOS. Such heterogeneous integration can overcome the incompatibility of PZT material with back-end-of-the-line (BEOL) CMOS technology. The PZT stack and the transfer process have been optimized to avoid degradation of the PZT actuators during the transfer. In particular, we have optimized the seed layer for

Roland Guerre; Ute Drechsler; Debabrata Bhattacharyya; Pekka Rantakari; Richard Stutz; Robert V. Wright; Zlatoljub D. Milosavljevic; Tauno Vaha-Heikkila; Paul B. Kirby; Michel Despont

2010-01-01

391

Design and Experiment of PZT Network-based Structural Health Monitoring Scanning System  

Microsoft Academic Search

The active Lamb wave and piezoelectric transducer (PZT)-based structural health monitoring (SHM) technology is a kind of efficient approach to estimate the health state of aircraft structure. In practical applications, PZT networks are needed to monitor large scale structures. Scanning many of the different PZT actuator-sensor channels within these PZT networks to achieve on-line SHM task is important. Based on

Qiu Lei; Yuan Shenfang; Wang Qiang; Sun Yajie; Yang Weiwei

2009-01-01

392

Ti-in-Zircon Thermometer: Preliminary Results  

Microsoft Academic Search

The titanium in zircon thermometer has been applied to 167 zircons from diverse rock types. These rocks include metamorphosed anorthosite and gabbro (1.15 Ga, intrusion age), and unmetamorphosed granitic pegmatite (0.9 Ga) from the Adirondack Highlands; metaluminous and peraluminous granites (114-90 Ma) of the Sierra Nevada Batholith; megacrysts from kimberlite pipes in southern Africa, Brazil, and Siberia; and detrital zircons

B. Fu; A. J. Cavosie; C. C. Clechenko; J. Fournelle; N. T. Kita; J. Lackey; F. Page; S. A. Wilde; J. W. Valley

2005-01-01

393

Trace element chemistry of zircons from oceanic crust: A method for distinguishing detrital zircon provenance  

NASA Astrophysics Data System (ADS)

We present newly acquired trace element compositions for more than 300 zircon grains in 36 gabbros formed at the slow-spreading Mid-Atlantic and Southwest Indian Ridges. Rare earth element patterns for zircon from modern oceanic crust completely overlap with those for zircon crystallized in continental granitoids. However, plots of U versus Yb and U/Yb versus Hf or Y discriminate zircons crystallized in oceanic crust from continental zircon, and provide a relatively robust method for distinguishing zircons from these environments. Approximately 80% of the modern ocean crust zircons are distinct from the field defined by more than 1700 continental zircons from Archean and Phanerozoic samples. These discrimination diagrams provide a new tool for fingerprinting ocean crust zircons derived from reservoirs like that of modern mid-ocean ridge basalt (MORB) in both modern and ancient detrital zircon populations. Hadean detrital zircons previously reported from the Acasta Gneiss, Canada, and the Narryer Gneiss terrane, Western Australia, plot in the continental granitoid field, supporting hypotheses that at least some Hadean detrital zircons crystallized in continental crust forming magmas and not from a reservoir like modern MORB.

Grimes, C. B.; John, B. E.; Kelemen, P. B.; Mazdab, F. K.; Wooden, J. L.; Cheadle, M. J.; Hanghøj, K.; Schwartz, J. J.

2007-07-01

394

Material nonlinear characteristics of the 3203HD PZT wafer under high electric fields  

Microsoft Academic Search

In this paper, material nonlinear behavior of a PZT wafer (3203HD, CTS) under high electric fields and stress is experimentally investigated and the nonlinearity of the PZT wafer is numerically simulated. Empirical functions that can represent the nonlinear behavior of the PZT wafer have been extracted based on the measured piezoelectric strain under stress. The functions are implemented in an

Sangki Lee; Sung-Hoon Jang; Young Sung Kim; Hoon Cheol Park; Kwang Joon Yoon

2005-01-01

395

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

Microsoft Academic Search

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,

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

2009-01-01

396

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

Microsoft Academic Search

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

Yunfeng Li; Roberto Horowitz

2002-01-01

397

Clash of the Titans  

NSDL National Science Digital Library

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

Subramaniam, Karthigeyan

2010-01-01

398

The Geology of Titan  

Microsoft Academic Search

Titan, the largest and most complex satellite in the solar system exhibits an organic dominated surface chemistry and shares surface features with other large icy satellites as well as the terrestrial planets. It is subject to tidal stresses, and its surface appears to have been modified tectonically. Cassini's global observations at infrared and radar wavelengths as well as local investigations

Ralf Jaumann

2010-01-01

399

Titan: An exogenic world?  

Microsoft Academic Search

All landforms on Titan that are unambiguously identifiable can be explained by exogenic processes (aeolian, fluvial, impact cratering, and mass wasting). Previous suggestions of endogenically produced cryovolcanic constructs and flows have, without exception, lacked conclusive diagnostic evidence. The modification of sparse recognizable impact craters (themselves exogenic) can be explained by aeolian and fluvial erosion. Tectonic activity could be driven by

Jeffrey M. Moore; Robert T. Pappalardo

2011-01-01

400

The lakes of Titan  

Microsoft Academic Search

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

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

401

Titan Plumes Revisited  

NASA Astrophysics Data System (ADS)

At the time of the Voyager 1 close encounter with Titan, enhancements of density and sharp decreases of electron temperature were observed by the PLS instrument. A few smaller plumes were identified inside and outside Titan orbit and their displacements correlated with variations in solar wind dynamic pressure observed by Voyager PLS one and two corotation periods earlier. At the time, two conflicting interpretations of this phenomenon were proposed. In one interpretation (Eviatar et al., JGR, 87, 8091, 1982, the enhancements were regarded as plumes drawn out of the ionosphere of Titan by the corotation electric field. The secondary enhancements were taken to be old plumes that had been wrapped around Saturn, had begun to decay and to merge into the magnetosphere environment. An alternative interpretation, proposed by Goertz (GRL, 1983, 10, 455), viewed them as blobs of plasmas detached by flute or Kelvin-Helmholtz instability from the central body of Saturn plasma in the inner magnetosphere. The Voyager PLS instrument was unable to make a firm composition determination which would have resolved the question. In this study, we use Cassini/CAPS data to identify plumes and blobs of plasma and classify them by source by means of composition and temperature. We find that all three types of plasma bodies, primary plumes, secondary wrapped around plumes and sloughed off blobs exist in the Titan-dominated region of the magnetosphere.

Eviatar, A.; Goldstein, R.; Young, D. T.; Arridge, C. S.; Coates, A. J.; Sittler, E. C.; Thomsen, M. F.; Wilson, R. J.

2008-12-01

402

Titan from Cassini  

NASA Astrophysics Data System (ADS)

Saturn's largest moon Titan is sometimes touted as the most Earth-like body in our solar system. Not only does it have a thick, nitrogen-dominated atmosphere featuring photochemical hazes, clouds and precipitation (where methane plays a similar role in Titan's atmosphere as water vapor does in Earth's), but also a surface that shows mountains, tectonic structures, impact craters, lakes, seas, river channels and deltas, large deserts with extensive dune fields, and volcanoes. Though these structures and processes appear similar to those of Earth, the whole dance is conducted at 9 astronomical units from the Sun, where a balmy, summer day on Titan is only 95 K, the lakes and seas are filled with liquid hydrocarbons, the bedrock is composed of water ice, the surface is covered with a thick layer of complex organics and nitriles, volcanoes have effused 170K ammonia-methane-water lavas onto the surface, and the dune fields are comprised of sand that's not dramatically different in composition from terrestrial smog. This talk will explore some of what has been learned about Titan's surface and atmosphere during Cassini's roughly 6-year tenure in orbit around Saturn.

Brown, Robert H.; Sotin, Christophe

403

The lakes of Titan  

USGS Publications Warehouse

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 the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70?? north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table. ??2007 Nature Publishing Group.

Stofan, E. R.; Elachi, C.; Lunine, J. I.; Lorenz, R. D.; Stiles, B.; Mitchell, K. L.; Ostro, S.; Soderblom, L.; Wood, C.; Zebker, H.; Wall, S.; Janssen, M.; Kirk, R.; Lopes, R.; Paganelli, F.; Radebaugh, J.; Wye, L.; 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.; Paillou, P.; Picardi, G.; Posa, F.; Roth, L.; Seu, R.; Shaffer, S.; Vetrella, S.; West, R.

2007-01-01

404

Composition of Titan's Surface  

Microsoft Academic Search

The Huygens Probe returned the first in situ data on Titan's surface composition in January 2005. Although Huygens landed on a dry plain, the Gas Chromatograph Mass Spectrometer (GCMS) showed evidence of methane moisture in the near subsurface suggesting methane precipitation at some time in the past. Heavier organic molecules were not found to be abundant in the atmosphere or

L. A. Soderblom; J. W. Barnes; R. H. Brown; R. N. Clark; M. A. Janssen; T. B. McCord; H. B. Niemann; M. G. Tomasko

2010-01-01

405

Semiconducting barium titanate  

Microsoft Academic Search

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

W. Heywang

1971-01-01

406

The atmosphere of Titan.  

PubMed

The discovery that Titan had an atmosphere was made by the identification of methane in the satellite's spectrum in 1944. But the abundance of this gas and the identification of other major constituents required the 1980 encounter by the Voyager 1 spacecraft. in the intervening years, traces of C2H2, C2H4, C2H6 and CH3D had been posited to interpret emission bands in Titan's IR spectrum. The Voyager infrared Spectrometer confirmed that these gases were present and added seven more. The atmosphere is now known to be composed primarily of molecular nitrogen. But the derived mean molecular weight suggests the presence of a significant amount of some heavier gas, most probably argon. It is shown that this argon must be primordial, and that one can understand the evolution of Titan's atmosphere in terms of degassing of a mixed hydrate dominated by CH4, N2 and 36Ar. This model satisfactorily explains the absence of neon and makes no special requirements on the satellite's surface temperature. The organic chemistry taking place on Titan today invites comparison with chemical evolution on the primitive Earth prior to the origin of life. PMID:7097773

Owen, T

1982-01-01

407

The Investigation of PMS-PNW-PZT Piezoelectric Ceramics  

Microsoft Academic Search

Pb0.95Sr0.05[(Mn1\\/3Sb2\\/3)0.06(Ni1\\/2W1\\/2)x(Zr0.49Ti0.51)1-x-0.06]O3 (PMS-PNW-PZT) (x = 0.01?0.04) were prepared by using traditional technique with solid reaction process. The effects of PNW contents and sintering temperatures on microstructure, dielectric and piezoelectric properties of PMS-PNW-PZT ceramics were investigated. When the amount of doping content was about 2 mol% and the sintering temperature was 1250°C, the optimum values of buck density, mechanical quality factor, dielectric loss,

Zhang Dong; Ma Weibing; Sun Qingchi; Gao Hongye; Zhang Yong

2010-01-01

408

Titan atmospheric composition  

NASA Astrophysics Data System (ADS)

Titan s atmospheric composition has become known to us from the Voyager missions and more recently through the explorations by the ISO and Cassini instruments ISO has provided the detection of the water vapor in Titan s atmosphere Coustenis et al 1998 and given a precise measure of the chemical composition as a disk-average Coustenis et al 2003 More recently data recorded by the Composite Infrared Spectrometer CIRS aboard the Cassini spacecraft became available during the recent Titan flybys Flasar et al 2005 Teanby et al 2006 The spectra characterize various regions on Titan from 75 r S to 75 r N with a variety of emission angles We study the emission observed in the mid-infrared CIRS detector arrays covering roughly the 600-1500 cm -1 spectral range with apodized resolutions of 2 54 or 0 53 cm -1 The composite spectrum shows several molecular signatures hydrocarbons nitriles and CO 2 A firm detection of benzene C 6 H 6 is also provided by CIRS at 674 cm -1 We have used temperature profiles retrieved from the inversion of the emission observed in the methane nu 4 band at 1304 cm -1 and a line-by-line radiative transfer code to infer the abundances of the trace constituents and some of their isotopes in Titan s stratosphere Coustenis et al 2006 No longitudinal variations were found for the gases Information is retrieved on the meridional variations of the trace constituents and tied to predictions by dynamical-photochemical models Molecules showing a significant enhancement at

Coustenis, A.; Cirs Investigation Team

409

Amorphous Pb(Zr, Ti)O 3 thin film hydrogen gas sensor  

Microsoft Academic Search

The capacitive Pd\\/lead zirconate titanate (PZT)\\/Pt devices have been fabricated with amorphous Pb(Zrx, Ti1?x)O3 (x=0, 30, 53, 65, 90) thin films deposited using the sol–gel spin-coating technology. The PZT films have been characterized by TGA, DTA, X-ray diffraction (XRD), dielectric and electrical properties, and gas sensitivity measurement. It has been shown that the amorphous PZT film can be operative as

J Deng; W Zhu; O. K Tan; X Yao

2001-01-01

410

On development of a multi-channel PZT array scanning system and its evaluating application on UAV wing box  

Microsoft Academic Search

Piezoelectric sensor (PZT) based structural health monitoring (SHM) methods can efficiently estimate the health condition of aircraft structures. To monitor large-scale structures, dense PZT arrays are usually needed. How to scan different PZT actuator–sensor channels in the PZT array to achieve a real time and stable SHM task is an important issue in the application of these methods. In this

Lie Qiu; Shenfang Yuan

2009-01-01

411

Diurnal tidal stresses on Titan  

NASA Astrophysics Data System (ADS)

Interior models and amplitude patterns of diurnal tidal stresses on Titan are calculated. The structural models are required to satisfy the satellite's mean density, polar moment-of-inertia factor MoI, and tidal potential Love number k2 as derived from Cassini gravity field data. The tidal stress pattern is found to correspond to the locations of cryovolcanic candidate areas on Titan's leading hemisphere. A relatively warm, low-ammonia water ocean could further increase Titan's habitable potential.

Sohl, F.; Solomonidou, A.; Wagner, F. W.; Coustenis, A.; Hussmann, H.; Schulze-Makuch, D.

2013-09-01

412

Properties of Semiconductive Barium Titanates  

Microsoft Academic Search

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.

Osamu Saburi

1959-01-01

413

New experimental constraints for Hadean zircon source melts from Ce and Eu anomalies in zircon  

NASA Astrophysics Data System (ADS)

A common feature of zircon rare earth element profiles is that they often have enriched chondrite normalized Ce abundances relative to bracketing rare earth elements (REEs) La and Pr. The magnitude of a zircon Ce anomaly is generally attributed to an increase in Ce4+/Ce3+ of the crystallizing medium (Ce4+ is more compatible than Ce3+ in zircon), which is associated with more oxidizing environments. Zircons may also have depleted chondrite normalized Eu abundances relative to Sm and Gd. A negative Eu anomaly may be indicative of more reducing conditions (Eu2+ is incompatible in zircon) or depletion of Eu in the melt from plagioclase prior to or during zircon crystallization. We report experimental data from zircons crystallized in hydrous peralkaline, metaluminous, and peraluminous melts (800-1300oC; 10 kbar) with the oxygen fugacity buffered from ~IW to HM+1 in order to constrain magnitude of zircon Ce and Eu anomalies. Zircon Ce anomalies increase in magnitude with higher oxygen fugacities and lower crystallization temperatures; Eu anomalies are more negative at ~IW vs. NNO for the same temperature and melt composition. Our experiments also show that with the oxygen fugacity buffered at NNO, zircons may have both positive Ce anomalies and negative Eu anomalies. Thus, Eu2+ and Ce4+ may co-exist in terrestrial melts; furthermore, melt depletion of Eu by plagioclase fractionation prior to (or during) zircon crystallization may not be a requisite for the presence of zircon Eu anomalies in (Hadean) zircons. The magnitude of the anomalies is also a function of the melt composition; peraluminous melts yield the largest positive Ce (or negative Eu) anomalies at a given oxygen fugacity and temperature. Extrapolation of our preliminary empirical calibration to the crystallization temperatures of the Jack Hills Hadean zircons (~700oC) suggests the magnitude of Ce anomalies in approximately half of the Hadean zircons cannot be produced in metaluminous or peralkaline melts, even at oxygen fugacities as high as HM+1. However, the magnitude of Ce anomalies in Hadean zircons is within the range of predicted anomalies of our experiments for peraluminous melts, implying that a significant portion of the Hadean zircon population may be derived from peraluminous melts. This result is consistent with muscovite inclusion mineralogy in Hadean zircons (e.g., Hopkins et al., 2008), but does not preclude the possibility of other, less evolved peraluminous source rocks, or some process which leads to significant Ce enrichment (relative to La and/or Pr) in the melt at the time of zircon crystallization.

Trail, D.; Watson, E. B.; Tailby, N.

2010-12-01

414

Modeling Zircon Saturation Within Simulated Impact Events  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

415

Transformation Strain in PZT 95\\/5 Ceramic  

Microsoft Academic Search

The ferroelectric ceramic PZT 95\\/5 transforms to an antiferroelectric phase under compressive loading. We have conducted quasistatic triaxial stress and dynamic uniaxial strain loading experiments on both poled and unpoled ceramic specimens to better understand this phase transformation. Different transformation strain states were observed in the quasistatic and dynamic impact tests reflecting the dependence of material response on loading path.

Stephen T. Montgomery; David H. Zeuch; Robert E. Setchell; Michael D. Furnish; Lalit C. Chhabildas

1999-01-01

416

Uniaxial Electromechanical Behavior of a Soft PZT: Experiments and Modeling  

Microsoft Academic Search

The aim of this work is to collect a database from uniaxial experiments and model the material behavior. A soft PZT is tested in compression; the influence of stress rate seems to be negligible and the material accommodates to cyclic mechanical loadings. These responses are simulated by means of a phenomenological model taking into account the coupling between remnant strain

Olivier Guillon; Patrick Delobelle; Frédéric Thiébaud; Vincent Walter; Dominique Perreux

2004-01-01

417

Observing Titan with amateur equipment  

NASA Astrophysics Data System (ADS)

We survey the observations of Titan that can be made using equipment available to amateur astronomers. Off-the-shelf hardware includes spectrometers and photometers that can detect Titan's infrared light curve and potentially its clouds. CCD spectra and photometry (both photoelectric and CCD), even with small (20 cm) telescopes, are useful for monitoring seasonal changes in Titan's haze. Recent remarkable advances in automatic stacking of thousands of short-exposure images obtained with webcams may even permit Titan's disk to be resolved. We additionally report some observations made with amateur equipment mounted on the 1.64 m Gerard P. Kuiper telescope on Mt. Bigelow.

Lorenz, Ralph D.; Hergenrother, Carl; White, Brooke; West, J. Doug; Fujii, Mitsugu; Hatton, Jason

418

Organic chemistry on Titan  

NASA Technical Reports Server (NTRS)

Features taken from various models of Titan's atmosphere are combined in a working composite model that provides environmental constraints within which different pathways for organic chemical synthesis are determined. Experimental results and theoretical modeling suggest that the organic chemistry of the satellite is dominated by two processes: photochemistry and energetic particle bombardment. Photochemical reactions of CH4 in the upper atmosphere can account for the presence of C2 hydrocarbons. Reactions initiated at various levels of the atmosphere by cosmic rays, Saturn 'wind', and solar wind particle bombardment of a CH4-N2 atmospheric mixture can account for the UV-visible absorbing stratospheric haze, the reddish appearance of the satellite, and some of the C2 hydrocarbons. In the lower atmosphere photochemical processes will be important if surface temperatures are sufficiently high for gaseous NH3 to exist. It is concluded that the surface of Titan may contain ancient or recent organic matter (or both) produced in the atmosphere.

Chang, S.; Scattergood, T.; Aronowitz, S.; Flores, J.

1979-01-01

419

RADAR Reveals Titan Topography  

NASA Technical Reports Server (NTRS)

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

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

2005-01-01

420

HASI Experiment to Titan  

NASA Astrophysics Data System (ADS)

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 electric properties and the nature of the surface. Accelerometers measured deceleration in all three axes as the probe was in the entry phase. With the aerodynamic properties of the probe already known, it has been possible to determine the density of Titan's high atmosphere and to deduce temperature and pressure profiles. During the descent (from 162 km down to the surface), temperature and pressure of the atmosphere were measured directly and the Permittivity and Wave Analyzer sensors measured the electron and ion conductivities as well as the complex permittivity of the atmosphere and searched for electric wave activity including lightning. Acoustic signals collected by the HASI microphone were processed by the on board FFT and their amplitude and main frequency, averaged over two minutes, were transmitted to the ground. The HASI instrument package had a total mass of 5.7 kg. The accelerometers package is mounted at the center of mass of the probe and the temperature sensors and the pressure probe inlet are mounted on a stem outside of the probe. Two deployable booms carrying Permittivity ad Wave electrodes stowed under the thermal shield of Huygens, has been released at the beginning of the descent into Titan's atmosphere. HASI provided, in addition to its own scientific data, calibration information of use by other instruments on Huygens and by remote sensing observations from the Cassini orbiter.

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

2005-08-01

421

Crystalline titanate catalyst supports  

DOEpatents

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.

Anthony, R.G.; Dosch, R.G.

1993-01-05

422

Titan’s “blandlands”: nature, distribution, and possible origin of Titan’s plains  

NASA Astrophysics Data System (ADS)

Titan’s diverse and Earth-like geologic features have been mapped and interpreted based on their morphological characteristics (e.g. Lopes et al., 2010, Icarus 205; Aharonson et al., 2012, Titan: Surface, Atmosphere, Magnetosphere, Cambridge University Press). While the interpretation for the origin of some units, such as dunes and well-preserved impact craters, has been relatively straightforward, others have been more challenging. In particular, the undifferentiated plains first mapped by Lopes et al. (2010) remain mysterious. These vast expanses, often referred to as “blandlands” (also “undifferentiated plains unit”, Lopes et al., 2010) are mostly found at mid-latitudes and appear relatively featureless at radar wavelengths, with no significant topography. Their gradational boundaries and paucity of features in SAR data make geologic interpretation particularly challenging. We examine and evaluate different formation mechanisms. Plains may be sedimentary in origin, resulting from fluvial or lacustrine deposition or accumulation of photolysis products created in the upper atmosphere. Alternatively, the plains may be cryovolcanic, consisting of overlapping flows of low relief, obscured by accumulation of sediments. In this paper, we use SAR, radiometry, scatterometry, and SARTopo data to examine the characteristics of the plains and compare them with other geologic units. We also compare their global distribution with that of other units and examine the implications.

Lopes, Rosaly M.; Malaska, M. J.; Le Gall, A.; Hayes, A.; Mitchell, K. L.; Kirk, R.; Radebaugh, J.; Neish, C.; Stofan, E.; Janssen, M.; Wall, S. D.; Lucas, A.; Lorenz, R. D.; Cassini RADAR Team

2013-10-01

423

Landscape Evolution of Titan  

NASA Technical Reports Server (NTRS)

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.

Moore, Jeffrey

2012-01-01

424

Dating metamorphism using zircons in metabasic rocks  

NASA Astrophysics Data System (ADS)

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.

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

2003-04-01

425

Titan’s induced magnetosphere under variable upstream conditions  

NASA Astrophysics Data System (ADS)

Over the last 5 years, Cassini magnetic field and plasma observations in the vicinity of Titan have revealed that the properties of the moon’s plasma environment are strongly influenced by the dynamics of Saturn’s equatorial magnetodisk. As the magnetodisk flaps past Titan’s orbit in response to changes in solar wind dynamic pressure and Saturn kilometric radiation phase, the pressure inventory of the flow ahead of the moon varies with implications on its atmopsheric escape. In this work we identify some basic properties of Titan’s induced magnetosphere (size, shape) and, in sectors where upstream conditions are less variable, we compare the importance of the different pressure terms (magnetic, dynamic, thermal) at different altitudes to study the pressure balance.

Bertucci, C.; Sillampaa, I.; Sittler, E. C.; Sergis, N.; Modolo, R.; Rymer, A.; Tokar, R. L.; Dougherty, M. K.; Young, D. T.; Krimigis, S. M.; Kurth, W. S.

2009-12-01

426

Inflight dissociation of zircon in air plasma  

NASA Astrophysics Data System (ADS)

Thermal dissociation of zircon can be conveniently carried out in a plasma reactor, which is characterized by high temperature, high energy density and high quench rate. Zirconia is recovered from this partially dissociated zircon by alkali leaching. Dissociation of zircon has been conventionally carried out in argon gas, which is expensive. The present paper reports experimental results on thermal dissociation of zircon in air plasma medium. Process simulation for 'inflight' dissociation of zircon in air plasma medium is also presented. The experimental system consists of a central hollow graphite electrode, which acts as the cathode and a graphite anode. The material to be processed is fed centrally through the cathode. The unique feature of the system is that it uses air as the working gas to generate the thermal plasma. The system has been used to study in-flight dissociation of zircon in the thermal plasma jet. Dissociation was carried out over 10-25 kW power range. Results of the study indicate that complete dissociation of zircon to ZrO2 and silica could be accomplished at 25 kW in air plasma.

Yugeswaran, S.; Ananthapadmanabhan, P. V.; Thiyagarajan, T. K.; Selvarajan, V.; Nair, Janardhanan

2010-02-01

427

Synthesis and electrical analysis of nano-crystalline barium titanate nanocomposites for use in high-energy density applications.  

SciTech Connect

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.

DiAntonio, Christopher Brian; Yang, Pin; Chavez, Tom P.; Huber, Dale L.; Winter, Michael R.; Monson, Todd C.; Roesler, Alexander William

2010-10-01

428

Titan's extended atmosphere: INCA results  

NASA Astrophysics Data System (ADS)

During the Titan flybyes INCA obtained ENA images of the interaction between the atmosphere of Titan and the magnetospheric ion fluxes sweeping over Titan with subcorotational speeds (~145 km/s). The ENA images show highly variable ENA fluxes from Titan due to the structure in the magnetospheric ion population. The ENA fluxes extend out to several 10,000 km altitude from the surface of Titan. We use a parametric neutral atmosphere model consisting of H, H2, N, and CH4 to simulate Hydrogen and Oxygen ENA images in the 20-80 keV range and compare to the images obtained by INCA. Several events are analyzed to investigate how the H2 distribution falls off with altitude.

Brandt, P. C.; Dialynas, K.; Dandouras, I.; Mitchell, D. G.; Garnier, P.; Krimigis, S. M.

2009-04-01

429

Solution Synthesis and Processing of PZT Materials for Neutron Generator Applications  

SciTech Connect

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.

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

1998-12-01

430