Titanate ceramics

Eig. 9. A typical sonochemical apparatus with dkect immersion ultrasonic horn. Ultrasound can be easily introduced into a chemical reaction with good control of temperature and ambient atmosphere. The usual pie2oelectric ceramic is PZT, a lead 2kconate titanate ceramic. Similar designs for sealed... 

R. D. Roseman, Influence ofYttria and Zirconia on the Positive Temperature Coefficient of Resistance in Barium Titanate Ceramics, M.S. dissertation. University of Illinois, Urbana, Dl. 1991. 

The contribution to the stress from electromechanical coupling is readily estimated from the constitutive relation [Eq. (4.2)]. Under conditions of uniaxial strain and field, and for an open circuit, we find that the elastic stiffness is increased by the multiplying factor (1 -i- K ) where the square of the electromechanical coupling factor for uniaxial strain, is a measure of the stiffening effect of the electric field. Values of for various materials are for x-cut quartz, 0.0008, for z-cut lithium niobate, 0.055 for y-cut lithium niobate, 0.074 for barium titanate ceramic, 0.5 and for PZT-5H ceramic, 0.75. These examples show that electromechanical coupling effects can be expected to vary from barely detectable to quite substantial. 

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... 

Hart, K. P., Zhang, Y. et al. 2000. Aqueous durability of titanate ceramics designed to immobilize excess plutonium. Materials Research Society Symposium Proceedings, 608, 353-358. 

Strachan, D. M., Scheele, R. D. et al. 2002. Radiation damage in titanate ceramics for plutonium immobilization. Materials Research Society Symposium Proceedings, 713, 461-468. 

The alteration of several titanate ceramics in pure water at 90 °C has been investigated by Leturcq et al. (2001). These experiments were performed under conditions of high surface area to volume ratio and lasted for over one year without replacement of the solution. Starting materials included melted Synroc-like materials and hot pressed Synroc-C. This study reported the normalized elemental mass losses, defined by the equation ... 

Ball, C. I, Buykx, W. J. et al. 1989. Titanate ceramics for the stabilization of partially reprocessed nuclear fuel elements. Journal of the American Ceramic Society, 72, 404-414. 

Fillet, C., Advocat, T., Bart, F., Leturcq, G. Rabiller, H. 2004. Titanate ceramics for separated long-lived radionuclides. Compte rendu de TAcademie des Sciences, in press. 

Mitamura, H., Matsumoto, S. et al. 1992. Aging effects on curium-doped titanate ceramic containing sodium-bearing high-level nuclear waste. Journal of the American Ceramic Society, 75, 392-400. 

Stewart, M. W. A., Begg, B. D. et al. 2003. Ion irradiation damage in zirconate and titanate ceramics for plutonium disposition. Proceedings of ICEM 03 The 9th International Conference on Radioactive Waste Management and Environmental Remediation, in press. 

The characterization work has shown that, although the titanate ceramic appears to be homogeneous on a macro scale, it is actually quite heterogeneous on an atomic scale and contains at least l4 different phases and possibly more. Since interactions of the waste form with any environment surrounding it will also occur on an atomic scale, it is important that this type of information be available when speculating on the long term stability of any waste form. 

Takeuchi, T., Tabuchi, M., Kondoh, I., Tamari, N., Kageyama, H., (2000), Synthesis of dense lead titanate ceramics with submicrometer grains by spark plasma sintering , J. Am. Ceram. Soc., 83, 541-544. 

Figure 13.7 Relaxation of the longitudinal piezoelectric coefficient in Sm-modified lead titanate ceramics at different temperatures.

Figure 13.8 Ilustration of the validity of the Kramers-Kronig relations for the piezoelectric relaxation in Sm-modified lead titanate ceramics. The imaginary component is calculated from the real using numerical method and Kramers-Kronig relations and compared with experimentally determined data.

Daniels, J., Hardtl, K.H., Hennings, D. and Wernicke, R. (1976) Defect chemistry and electrical conductivity of doped barium titanate ceramics. Philips Research Reports 31, 487-559. 

The dielectric characteristics of barium titanate ceramics with respect to temperature, electric field strength, frequency and time (ageing) are very dependent on the substitution of minor amounts of other ions for Ba or Ti. 

Frey, M.H. et al. (1998) The role of interfaces on an apparent grain size effect on the dielectric properties for ferroelectric barium titanate ceramics, Ferroelectrics, 206-207, 337-53. 

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

Basantakumar Sharma and Sarma H. N. K., A Mansingh, Ferroelectric and dielectric properties of sol-gel processed barium titanate ceramics and thin film. J. Materials Science. 34(1999) pp. 1385-1388. 

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