Ferroelectric properties of intergrowth Bi4Ti3O12–SrBi4Ti4O15 ceramics

Ferroelectric intergrowth ${\mathrm{Bi}}_{\mathrm{4}}{\mathrm{Ti}}_{\mathrm{3}}{\mathrm{O}}_{\mathrm{12}}–{\mathrm{SrBi}}_{\mathrm{4}}{\mathrm{Ti}}_{\mathrm{4}}{\mathrm{O}}_{\mathrm{15}}$ has been demonstrated to have a large remanent polarization ${\text{(2P}}_r)$ of 30 μC/cm² and a high Curie temperature of 610 °C using bulk ceramics. The Rietveld analysis of the powder x-ray diffraction patterns showed that there are two kinds of Bi ions in ${\mathrm{Bi}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{2}}$ layers. One Bi ion in the ${\mathrm{Bi}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{2}}$ layers was displaced to the other Bi ion along the polarization direction by about 2% of parameter a, which would contribute to the large ${\text{2P}}_r.$