Dielectric and photoelectric material. Occurs in nature as the mineral tausonite. Optical properties: H. A. Weakliem et al., RCA Rev. 36, 149 (1975). Electrical conductivity: U. Balachandran, N. G. Eror, J. Solid State Chem. 39, 351 (1981). Dielectric properties of glass-ceramics: S. L. Swartz, A. S. Bhalla, Ferroelectrics 87, 141 (1988). Review of growth and properties of single crystals: K. Nassau, A. E. Miller, J. Cryst. Growth 91, 373-381 (1988). Prepn by sol-gel method: J. Moreno et al., J. Mater. Chem. 5, 509 (1995); by solution-precipitation method: V. Kumar, J. Am. Ceram. Soc. 82, 2580 (1999). Prepn of thin films by ECR plasma sputtering: S. Miyake et al., Surf. Coat. Technol. 169-170, 27 (2003); by spray pyrolysis: G. Brankovic et al., J. Eur. Ceram. Soc. 24, 989 (2004). Piezoelectric response at cryogenic temperatures: D. E. Grupp, A. M. Goldman, Science 276, 392 (1997). IR characterization of thin films: B. G. Almeida et al., Appl. Surf. Sci. 238, 395 (2004). Room-temperature ferroelectricity: J. H. Haeni et al., Nature 430, 758 (2004).