Lead titanates

Lead-tin Lead-tin-indium Lead-tin-silver alloys Lead-tin solder Lead titanate... 

Typical electrostrictive materials include such compounds as lead manganese niobate lead titanate (PMN PT) and lead lanthanium 2irconate titanate (PLZT). Electrostriction is a fourth-rank tensor property observed in both centric and acentric insulators (14,15). 

Simple ABO compounds in addition to BaTiO are cadmium titanate [12014-14-17, CdTiO lead titanate [12060-00-3] PbTiO potassium niobate [12030-85-2] KNbO sodium niobate [12034-09-2], NaNbO silver niobate [12309-96-5], AgNbO potassium iodate [7758-05-6], KIO bismuth ferrate [12010-42-3], BiFeO sodium tantalate, NaTaO and lead zirconate [12060-01 -4], PbZrO. The perovskite stmcture is also tolerant of a very wide range of multiple cation substitution on both A and B sites. Thus many more complex compounds have been found (16,17), eg, (K 2 i/2) 3 ... 

Another important class of titanates that can be produced by hydrothermal synthesis processes are those in the lead zirconate—lead titanate (PZT) family. These piezoelectric materials are widely used in manufacture of ultrasonic transducers, sensors, and minia ture actuators. The electrical properties of these materials are derived from the formation of a homogeneous soHd solution of the oxide end members. The process consists of preparing a coprecipitated titanium—zirconium hydroxide gel. The gel reacts with lead oxide in water to form crystalline PZT particles having an average size of about 1 ]lni (Eig. 3b). A process has been developed at BatteUe (Columbus, Ohio) to the pilot-scale level (5-kg/h). 

Lead antimonate [13510-89-9] (Naples yellow), Pb2(Sb0 2> mol wt 993.07, d = 6.58g/cm, is an orange-yeUow powder that is insoluble in water and dilute acids, but very slightly soluble in hydrochloric acid. Lead antimonates are modifiers for ferroelectric lead titanates, pigments in oil-base paints, and colorants for glasses and glazes (see Colorants for ceramics). They are made by the reaction of lead nitrate and potassium antimonate solutions, followed by concentration and crystallization. 

Lead zirconate [12060-01 -4] PbZrO, mol wt 346.41, has two colorless crystal stmctures a cubic perovskite form above 230°C (Curie point) and a pseudotetragonal or orthorhombic form below 230°C. It is insoluble in water and aqueous alkaUes, but soluble in strong mineral acids. Lead zirconate is usually prepared by heating together the oxides of lead and zirconium in the proper proportion. It readily forms soHd solutions with other compounds with the ABO stmcture, such as barium zirconate or lead titanate. Mixed lead titanate-zirconates have particularly high piezoelectric properties. They are used in high power acoustic-radiating transducers, hydrophones, and specialty instmments (146). 

Alkaline-Earth Titanates. Some physical properties of representative alkaline-earth titanates ate Hsted in Table 15. The most important apphcations of these titanates are in the manufacture of electronic components (109). The most important member of the class is barium titanate, BaTi03, which owes its significance to its exceptionally high dielectric constant and its piezoelectric and ferroelectric properties. Further, because barium titanate easily forms solid solutions with strontium titanate, lead titanate, zirconium oxide, and tin oxide, the electrical properties can be modified within wide limits. Barium titanate may be made by, eg, cocalcination of barium carbonate and titanium dioxide at ca 1200°C. With the exception of Ba2Ti04, barium orthotitanate, titanates do not contain discrete TiO ions but ate mixed oxides. Ba2Ti04 has the P-K SO stmcture in which distorted tetrahedral TiO ions occur. 

Lead titanate (PbXi03) by reacting ethyl titanate and lead vapor in oxygen and nitrogen at 500-800°C. 

Lead titanate (PbTi03) is a ferroelectric material with unusual pyroelectric and piezoelectric properties. It is deposited by MOCVD from ethyl titanate and lead vapor in oxygen and nitrogen at 500-800°C.[42]... 

Lead titanate (PbTiOg) with excellent pyroelectric and piezoelectric properties. 

Budd, K. D. 1986. Structure evolution in sol-gel derived lead titanate-based materials, and application to the processing of thin dielectric layers. PhD dissertation. University of Illinois at Urbana-Champaign. 

Lead titanate (PT), 5 583 as ferroelectric, 5 605-608 Lead titanate, 14 797 25 47 Lead titanate-zirconates, 14 797 Lead transport mechanisms, 25 394 Lead trioxide, 14 787-788 Lead users, role in product design, 5 761, 766... 

Jaffe, B., Roth, R. S., and Marzullo, S. (1954). Piezoelectric properties of lead zirconate-lead titanate solid-solution ceramics. J. Appl. Phys. 25, 809-810. 

Approximately ten years ago, it was first reported by Haertling and Land (jj that optical transparency was achieved in a ferroelectric ceramic material. This material was, in reality, not just one composition but consisted of a series of compositions in the lanthanum modified lead zirconate-lead titanate (PLZT) solid solution region. The multiplicity of compositions, each with different mechanical, electrical and electrooptic properties has led to a decade of study in defining the chemical and structural nature of these materials in understanding the phenomena underlying their optical and electrooptic properties and in evaluating the practicality of the large number of possible applications (2-12),... 

PLZT Compositional System. The solid solution region which forms the basis of the PLZT materials is a series of compositions resulting from the complete miscibility of lead zirconate and lead titanate (commonly designated at PZT) in each other. Modifications to the PZT system by the addition of lanthanum oxide has a marked beneficial effect upon several of the basic properties of the material such as decreased coercive field and increased dielectric constant, electromechcuiical coupling coef-... 

Barium titanate is one example of a ferroelectric material. Other oxides with the perovskite structure are also ferroelectric (e.g., lead titanate and lithium niobate). One important set of such compounds, used in many transducer applications, is the mixed oxides PZT (PbZri-Ji/Ds). These, like barium titanate, have small ions in Oe cages which are easily displaced. Other ferroelectric solids include hydrogen-bonded solids, such as KH2PO4 and Rochelle salt (NaKC4H406.4H20), salts with anions which possess dipole moments, such as NaNOz, and copolymers of poly vinylidene fluoride. It has even been proposed that ferroelectric mechanisms are involved in some biological processes such as brain memory and voltagedependent ion channels concerned with impulse conduction in nerve and muscle cells. 

Poled ceramic, c-axis along poling axis, t Lead titanate-zirconate. t 3.4mole°/oY203. 

Electroceramics. Titanates like barium, strontium, calcium and lead titanate prepared from finely divided, high-purity TiOz hydrolysates are used in capacitors, PTC-resistors and piezoelectric materials. The specifications of the Ti02 starting materials with respect to purity, reactivity, and sintering properties are expected to become more stringent. The market is estimated to be several thousand of tonnes a year as TiOz. A strong annual growth is expected. 

S.-S. Jan, J.-L. Chiang, Y.-C. Chen, J.-C. Chou, and C.-C Cheng, Characteristics of the Hydrogen Ion-Sensitive Field Effect Transistors with Sol-Gel-Derived Lead Titanate Gate, Anal. Chim. Acta 2002,469, 205. 

Electrostrictive materials are materials that exhibit a quadratic relationship between mechanical stress and the square of the electnc polarization. Electrostriction can occur in any material. Whenever an electric field is applied, the induced charges attract each other, thus, causing a compressive force. Tlus attraction is independent of the sign of the electnc field. Typical electrostrictive materials include such compounds as lead manganese niobate, lead titanate (PMN FT), and lead lanthanium zirconate titanate (PLZT). 

The success of an ultrasonic NDC application depends upon the selection of the best-qualified transducer (i.e., one with optimum frequency response, pulse width and shape). Transducer characteristics can be customized through the use of the best-suited piezoelectric material, such as lead zirconate-lead titanate, lead metaniobates, polymer piezoelectrics, and other advanced ferro-electric materials. 

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