PbTiOs-PbZrOs

Figure 14. Phase diagram for the PZT (PbTiOs -PbZrOs) system. Tetragonal and rhombohedral phase fields are separated by a nearly vertical morphotropic phase boundary (MPB). Adapted from Figure 1 in Oh and Jang (1999).

Sol-gel processing of PbTiOs, PbZrOs, PZT and PLZT thin films. Br. Ceram. Proc., 36,107. 

BaTiOq, PbTiO. PbZrO C1-5 alcohols, methyl acetate, acetone HCl, cellulose nitrate, methyl polymethacrylate, collodion 42... 

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 ... 

In lead zh conate, PbZrOs, the larger lead ions are displaced alternately from the cube corner sites to produce an antifeiToelectric. This can readily be converted to a feiToelectric by dre substitution of Ti" + ions for some of the Zr + ions, the maximum value of permittivity occumirg at about the 50 50 mixture of PbZrOs and PbTiOs. The resulting PZT ceramics are used in a number of capacitance and electro-optic applicahons. The major problem in dre preparation of these solid soluhons is the volatility of PbO. This is overcome by... 

Materials of particular interest are the perovskite oxides BaTiOs-SrTiOs (BST) and PbZrOs-PbTiOs (PZT) solid solutions as well as the layered perovskites based upon SrBi2Ta209 (SBT). Since the ferroelectric effect requires... 

Figure 937. A. Static and MAS NMR spectra of PbTiOs, B. Static and MAS "Pb NMR spectra of PbZrOs. From Zhao et al. (1999), by permission of the American Chemical Society.

Reaction of the PbO solid solution with the remaining PbTiOs and Zr02 to form Pb (Zr, Ti)03 solid solution with wide range of Zr/Ti ratios. It has been suggested that a PbZrOs-rich solid solution is initially formed, along with a PbTiOs-rich solid solution. ... 

Solid solutions between lead zirconate (PbZrOs) and lead titanate (PbTiOs) are known by the acronym PZT and are the most widely used of all piezoelectric ceramics. 

Piezoelectric materials based on the solid solutions of PbZrOs (PZ) and PbTiOs (PT) have been studied already for 50 years (Buchanan 1986 Berhncourt 1981 Cross 1996 Levinson 1988 Nowotny 1992 Newnham and Ruschau 1996 Okazaki 1985). System is known as PZT ceramics. It has excellent piezoelectric properties, which could be designed to meet specific application needs also by doping by different substitution atoms. Because of very reasonable price PZT ceramics is widely used in applications today (Table 7.14). 

The cubic perovskite CaTiOa structure (Fig. 2.10) is more complicated and found as the high-temperature modihcation of different crystals (SrTiOs, BaTiOs, PbTiOs, SrZrOs.PbZrOs). 

Certain ternary solid solutions containing BTO as one of their major phase components show excellent piezoelectric properties in the vicinity of MPB. They have been considered as a potential replacement for existing lead-based piezoelectric perovskite, PbZrOs-PbTiOs, PMT-PT, and so on. In fact, the extremely high piezoelectric response of PZT and PMN-PT has been partially attributed to the presence of a MPB between rhombohedral and tetragonal phases at that concentration [12]. Therefore, the presence of a MPB is considered as a necessary component of a lead-free replacement material due of the enhancement in properties observed for compositions at or near MPB. The basic approach to achieve high piezoelectricity is to choose the composition of the material at the proximity of a MPB of the phase diagram. The strong piezoelectric and dielectric responses at the vicinity of MPB have been ascribed to the low polarization anisotropy (rotation of FE polarization between two equivalent states) and elastic softness at MPB. 

The most important EO ceramics are solid-solution phases in the PbZrOs-PbTiOs-LaiOs system known collectively as PLZT materials. 

Early Evolutionary Stages of Condensation and Crystallization in Acid and Base Catalyzed PbZrOs-PbTiOs Gels A High-Resolution Electron Microscopic Study, Z.C. Kang, S.K. Dey and L. Eyring. In A.S. Bhalla and K.M. Nair (Eds.), The Ceramic Transactions-Ferroelectric Films, vol. 25, American Ceramic Society, Westerville, OH, p. 129, 1992. 

The development of sol-gel chemistry for the fabrication of oxide thin films by CSD started first in the 1980s with the deposition of transparent coatings of silica layers [9,10]. Immediately after these works, the CSD preparation of crystalline complex oxide thin films was reported, first by Fukushima [11] for BaTiOs films and a year later by Budd et al. [12] for PbTiOs and PbZrOs films. Since then, CSD has been widely used for the preparation of electroceramic thin films. 

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