Ferroelectric and Optic Properties of the Translucent BaTiO₃ Ceramics Derived from Nanocrystalline Monolith

ABSTRACT

Polycrystalline, translucent barium titanate (BaTiO₃) ceramics were successfully fabricated from partially crystallized, transparent monolithic xerogels produced by a high concentration sol-gel method using metal alkoxides. The xerogels yielded dense and translucent BaTiO₃ ceramics after heat treatment at 1100°C for 1 h in oxygen flow, with an average grain size of about 0.5 μ m and a relative sintered density of 97%. The transmittance of a ceramic (0.2 mm thick) was observed to increase almost linearly with wavelength of light, showing a transmittance of 32% at 800 nm. The dielectric constant of the ceramics at room temperature was found to be 1500, and the remanent polarization and coercive field were 2 μ C/cm² and 5 kV/cm, respectively. The variation of transmittance for a ceramic as a function of applied electric field to examine the material's electro-optic property was also measured.

Keywords:

• Sintering
• sol-gel processes
• BaTiO3
• dielectric properties
• optical properties

ACKNOWLEDGEMENTS

This work was supported by the Grant-in-Aid for Science Research (Grant No. 09305043) from the Ministry of Education, Science, Culture, and Sports of Japan.