Lead zirconate titanate, piezoelectric

PZr is the trade name of the lead zirconate titanate piezoelectric ceramics of one of its largest producer, Vcmiiron. It is also commonly used in the scientific literature as a standard acronym. 

The development of active ceramic-polymer composites was undertaken for underwater hydrophones having hydrostatic piezoelectric coefficients larger than those of the commonly used lead zirconate titanate (PZT) ceramics (60—70). It has been demonstrated that certain composite hydrophone materials are two to three orders of magnitude more sensitive than PZT ceramics while satisfying such other requirements as pressure dependency of sensitivity. The idea of composite ferroelectrics has been extended to other appHcations such as ultrasonic transducers for acoustic imaging, thermistors having both negative and positive temperature coefficients of resistance, and active sound absorbers. 

Nickel is being used ia magnetostrictive transducers ia some ultrasonic devices, eg, solderiag irons and ultrasonic cleaners, because of its moderate magnetostriction and availabiUty. This market, however, is dominated by piezoelectric transducers of lead zirconate—titanate (PZT) (see Ultrasonics). 

Zirconate compounds exhibit several interesting properties. Lead zirconate—titanate [12626-81 -2] compositions display piezoelectric properties which are utilized in the production of EM-coupled mode filters, resonators in microprocessor clocks, photoflash actuators, phonograph cartridges, gas... 

PZT (lead zirconate titanate) and PLZT (lead lanthanum zirconate titanate) combine ferroelectic, optical, and electronic properties and are used in optoelectronic and piezoelectric devices. Powders for hot pressing produced by CVD are being investigated. 

A variety of piezoelectric transducers have been employed for PAC. Ceramic transducers, usually lead zirconate titanate, are most commonly employed because of their sensitivity, time resolution and commercial availability. However, their acoustic response is often dominated by their own resonance, and so polymeric film detectors, such as polyvinylidenedifluoride, are often used. These piezoelectric materials are non-resonant, but not as sensitive as the ceramic detectors. Again, each detector has its own advantages (and disadvantages).14,15... 

See Local density of states Lead zirconate titanate ceramics 217—220 chemical composition 218 coupling constants 220 Curie point 218 depoling field 219 piezoelectric constants 220 quality number 219 Leading-Bloch-waves approximation 123 Level motion-demagnifier 271 Liquid-crystal molecules 338 Living cell 341... 

See Lead zirconate titanate ceramics Piezoelectric constants 220 Piezoelectricity 213—221... 

See Lead zirconate titanate ceramics Quality number 219 Quantum transmission 59 Reciprocal space 123, 353 Reciprocity principle 88 Reconstruction 14, 327 Au(lll) 327 DAS model 16 Si(lll)-2X1 14 Recursion relations 352 Repulsive atomic force 185, 192 Resonance frequency 234, 241 piezoelectric scanners 234 vibration isolation system 241 Resonance interactions 171, 177 and tunneling 177 Resonance theory of the chemical bond 172... 

A wide array of ferroelectric, piezoelectric and pyroelectric materials have titanium, zirconium and zinc metal cations as part of their elemental composition Many electrical materials based on titanium oxide (titanates) and zirconium oxide (zirconates) are known to have structures based on perovskite-type oxide lattices Barium titanate, BaTiOs and a diverse compositional range of PZT materials (lead zirconate titanates, Pb Zr Tij-yOs) and PLZT materials (lead lanthanum zirconate titanates, PbxLai-xZryTii-yOs) are among these perovskite-type electrical materials. 

There are two principal types of materials that can function as piezoelectrics the ceramics and polymers. The piezoelectric materials most widely used are the piezoceramics based upon the lead zirconate titanate, FZT. The advantages of these piczoccramics arc that they have a high piezoelectric activity and they can be fabricated in many different shapes. 

Fig. 9. A typical sonochemical apparatus with direct immersion ultrasonic hom. Ultrasound can be easily introduced into a chemical reaction with good control of temperature and ambient atmosphere. The usual piezoelectric ceramic is PZT, a lead zirconate titanate ceramic. Similar designs for sealed...

Micropumps based on piezoelectrics are made of pumping chambers that are actuated by three piezoelectric lead zirconate titanate disks (PZT). The pump consists of an inlet, pump chambers, three silicon membranes, three normally closed active valves, three bulk PZT actuators, three actuation reservoirs, flow microchannels, and outlet. The actuator is controlled by the peristaltic motion that drives the liquid in the pump. The inlet and outlet of the micropump are made of a Pyrex glass, which makes it biocompatible. Gold is deposited between the actuators and the silicon membrane to act as an upper electrode. Silver functions as a lower electrode and is deposited on the sidewalls of the actuation reservoirs. In this design, three different pump chambers can be actuated separately by each bulk PZT actuator in a peristaltic motion. 

Mixing can be achieved by ultrasound using lead zirconate titanate (PZT), a piezoelectric ceramic, operated in the kHz region [22], In this way, liquid streams can be moved and even turbulent-like eddies are induced. Favorably, ultrasonic action is coupled into a closed volume, a micro chamber. Here, the creation of standing waves has been reported. 

Longtu, Li. et al. (1990) Lead zirconate titanate ceramics and monolithic piezoelectric transformer of low firing temperature, Ferroelectrics, 101, 193-200. 

Sonication This involves the generation of shear forces in a cell sample in the vicinity of a titanium probe (0.5 mm in diameter and 10 cm long) that vibrates at 20,000 Hz. The device contains a crystal of lead zirconate titanate that is piezoelectric, i.e., it expands and contracts when an oscillatory electric field is applied to it from an electronic oscillator. The ultrasonic pressure waves cause microcavitation in the sample, and this disrupts the cell membranes, usually in a few seconds. 

As concerns the piezoelectric layer, the first choice often goes to lead zirconate titanate (PZT) because of its outstanding piezoelectric, pyroelectric and ferroelectric properties. Nickel ferrite (NF) is not widely employed for the synthesis of the multilayered composites owing to a strong reduction of its magnetization in the lower grain size limit. However, a very thin NF layer can help to attain entirely different properties and, hence, this material has been chosen as a sandwiched layer in the present work. 

The sensor is illustrated schematically in Fig. 1. The piezoelectric-excited millimeter-sized cantilever (PEMC) sensor is a macro-cantilever that comprises piezoelectric layer (lead zirconate titanate PZT) layer bonded to a nonpiezoelectric layer of a few millimeters in length and 1 mm in width (9,21). We use the direct piezoelectric effect to excite the cantilever, and the same PZT film senses the resulting response. PZT film is bonded to a base glass... 

The operating temperature of a piezoelectric transducer is dictated by the Curie temperature of the piezoelectric ceramic and its front-end coupling material. Commonly used ceramics are lead zirconate titanates (PZTs) whose... 

Ferroelectric composites are alternatives to standard piezoelectric and pyroelectric ceramics such as lead zirconate titanate (PZT) and BaHOs (BT). They combine the strong ferroelectric and dielectric properties of ceramics with the easy processing and good mechanical properties of polymers. Dispersion of micrometer-sized ferroelectric particles in an electrically passive epoxy matrix was first published by Furukawa et al. [1976] and later extended to ferroelectric matrices such as poly(vinylidene fluoride) (PVDF) and poly(vinylidene fluoride-co-3-fluoroethylene) (PVDF-TrFE) [Hsiang et al., 2001 Hilczer et al., 2002 Gimenes et al., 2004 Lam et al., 2005 Beloti et al., 2006]. However, the necessity of miniaturization of electronic components and... 

Ultrasonication involves the conversion of a conventional 50 / 60 Hz alternating-current line power to 20 kHz electrical energy and transformation to mechanical vibration. A lead zirconate titanate electrostrictive (piezoelectric) crystal, when subjected to alternating voltage, expands and contracts. This transducer vibrates longitudinally and transmits this motion to the horn tip. The horn tip is immersed in the liquid slurry and cavitation... 

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