Crystal Structure Analysis of High TC Barium Titanate – Bismuth Perovskite-Type Oxide System Ceramics and their Piezoelectric Property
Barium titanate (BaTiO3, BT) – bismuth titanate magnesium oxide (Bi(Mg0.5Ti0.5)O3, BMT) solid solution system ceramics were prepared by conventional sintering method in pursuit of the enhancement of the BT Curie temperature (TC, 132 °C). Normal ferroelectric polarization vs. electric-field (P-E) hysteresis loops were observed for BT-BMT ceramics with BMT contents below 20 and above 60 molar%. On the other hand, broad P-E double hysteresis loops were observed for BMT contents from 30 to 50 molar%. The origin was investigated using synchrotron XRD measurement and Rietveld analysis. The crystal structure was assigned to ferroelectric phase with domain-pinning by certain defect structures. A modified phase diagram was proposed on the basis of the temperature dependence of the crystal structure.
Shinobu Fujihara and Tadashi Takenaka
K. Yamato et al., "Crystal Structure Analysis of High TC Barium Titanate – Bismuth Perovskite-Type Oxide System Ceramics and their Piezoelectric Property", Key Engineering Materials, Vol. 445, pp. 23-26, 2010