Bismuth titanate

Bismuth titanate (Bi4Ti30i2) by reacting triphenyl bismuth, Bi(C5H5)3 and titanium isopropoxide at 600-800°C and 5 Torr. 

Another ferroelectric material is bismuth titanate, (Bi4Ti30i2), which is deposited from triphenyl bismuth, Bi(C5H5)3, and titanium isopropoxide at low pressure (5 Torr) and at temperatures of 600-800°C.[43]... 

Bismuth titanate, Bi4Ti30j2, with a high dielectric constant and a high dielectric strength. 

These pellets can be ground for powder x-ray studies, or electrodes can be evaporated on the flat surfaces of the pellets to produce samples for ferroelectric measurements. However, for more meaningful measurements single crystals of bismuth titanate are required. 

High-quality, pore-free microstructures of PZ - PT piezoceramic, (b) and (c), are essential for reliable, high-performance applications, e.g. composites and arrays where very small elements are cut from larger pieces (e.g. see Fig. 6.36) (d) the layer-structured bismuth titanate ferroelectric (Bi4Ti3012) Tc 650°C the crystal structure consists of perovskite layers separated by bismuth oxide layers) is exploited in high-temperature applications, including accelerometers and flow-meters (reproduced with permission of Ferroperm Piezoceramics A/S, Denmark). 

Perovskite-related Oxides.—The perovskite-related oxides have been studied extensively in recent years because of the large variety of device applications for which these materials are suited. The interaction between structure, properties, and stoicheiometry is significant at all levels, but here we will discuss only the narrow areas where intergrowth is a dominant structural feature. We will not, therefore, consider solid solutions typified by the Pb(Zr Tii )03 ferroelectrics, and neither will we discuss the structurally complex but stoicheiometric phases related to hexagonal BaTiOj, which includes BaNiOj, which has a simple two-layer repeat in the c-direc-tion, the nine layer BaRuOj, the twelve layer Ba4Re2CoOj2, and the twenty-four layer Sr5Re20ig phase. The crystal chemistry of these phases is treated in detail by Muller and Roy. The materials we shall discuss are the two series of phases A B 0 +2 and A + B 02n+, and the bismuth titanates. Some of the anion deficient perovskites, ABO -x, will be considered in Section 5. 

The Bismuth Titanates. This family of materials was one of the first complex perovskite groups to be discovered the early studies being made by Aurivillius and reported in 1949. The structures are well known and described in standard texts such as Wells. The general architectural principle of these materials is a repetition of perovskite layers n octahedra thick cut parallel to (110) as in the Sr +iTi 03 +i oxides described above. Instead of being held together by a sequence of SrO layers, the perovskite layers in the bismuth titanates are joined by (Bi202) layers. The perovskite slabs have an overall formula where /I is a large cation that can readily... 

Table 5 Some bismuth titanate related phases ...

Hong, S.-H., Trolier-McKinstry, S. and Messing, G. L., Dielectric and electromechanical properties of textured niobium-doped bismuth titanate ceramics, J. Am. Ceram. Soc., 83, 113-18, 2000. 

Watanabe, H., Kimura, T, and Yamaguchi, T. (1989) Particle orientation during tape casting in the fabrication of grain-oriented bismuth titanate. /. Am. Ceram. Soc., 72 (2), 289-293. 

Jones, J.L., Vogel, S.C., Slamovich, E.B., and Bowman, KJ. (2004) Quantifying texture in ferroelectric bismuth titanate ceramics. Scripta Mater, 51, 1123-1127. 

Phase separation in lead zirconate titanate and bismuth titanate during electrical shorting and fatigue. /. Appl, Phys., 99 (4), 044101. 

S.D., and Lee, J. A new ferroelectric material for use in FERAM Lanthanum-substituted bismuth titanate. 

Ding, Y., Liu, J.S., Qin, H.X., Zhu, J.S., and Wang, Y.N. (2001) Why lanthanum-substituted bismuth-titanate becomes fatigue free in a ferroelectric capacitor with platinum electrodes. Appl. Phys. Lett., 78, 4175-4177. 

Figure 9.24 Exploitation of controlled anisotropic abnormal grain growth (a) Self-reinforced silicon nitride, showing the interaction of a propagating crack with the micro-structure (magnification 2000 X ). (Courtesy of M. J. Hoffmann.) (b) Bismuth titanate with a microshucture of aligned anisotropic grains, giving anisottopic dielectric properties, (magnification 1000 X ).

Property Pz34 doped PbTiOs Pz35 lead metaniobate Pz46 bismuth titanate BaTiOs ceramics... 

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