Crystal Structure and Ferroelectric Properties of Si Added SrBi₂Ta₂O₉

Abstract

We investigated a series of bulk, ceramic samples of Si-added bismuth layered-structure compounds, SBTS, prepared by alloying SrBi2Ta2O9 with Bi2SiO5 or Bi4Si3O12 using a solid-state reaction method. X-ray and neutron powder diffraction were carried out to determine the crystal structures. Structural information is correlated with the measured data of the ferroelectric properties. We find that remanent polarization and coercive electric field increase with the addition of Bi2SiO5 or Bi4Si3O12 in SrBi2Ta2O9. The dielectric constants of SBTS increase markedly with increasing temperature. It is found that the ferroelectric behavior is related to the distortion and tilting of the TaO6 octahedron that are effected by variations in Bi and Si contents, respectively, in the SBTS samples.