Phase Formation and Dielectric Properties of Ferroelectric CaBi₄Ti_3.6B_0.4O₁₅ Ceramics (B – Ti, Cr, Ta)

Abstract

Layer-structured bismuth calcium titanate CaBi₄Ti₄O₁₅ is regarded as one of the promising candidates among lead-free oxides for high temperature piezoelectric applications due to its high Curie temperature T_C > 1000 K. Influence of partial cation substitutions on phase formation, microstructure and dielectric properties of CaBi₄Ti_3.6 B _0.4O₁₅ (B – Ti, Cr, Ta) ceramics was studied. Ceramic solid solutions were synthesized by the conventional ceramic method and studied using the X-ray diffraction, scanning electron microscopy and dielectric spectroscopy over a wide temperature and frequency ranges. It was proved that Mn₂O₃ and Bi₂O₃ additives enhanced the phase formation process, improved density of ceramics and their dielectric properties.

Keywords:

• Bismuth-containing ceramic solid solutions
• ferroelectric phase transitions
• dielectric properties

Acknowledgments

E.D. Politova expresses warmest gratitude to Professor W. Kleemann for pleasure of fruitful communications during our meetings over more than 10 years.

The financial support by the Russian Foundation for Basic Research (grant 10-03-91161) is acknowledged.