Effect of VO B-site substitution on the microstructure, Raman spectrum, and dielectric properties of SrBiTaO ceramics.

Strontium bismuth tantalate vanadate [SrBi(TaV)O, SBTV] ceramics, which are bismuth-layered perovskite ferroelectrics, were synthesized through the solid-state reaction method. The effects of different sintering temperatures and VO contents on the structure of the microstructure, Raman spectrum, and dielectric properties of the SBTV ceramics were investigated. As sintered at high temperature (980-1040 °C) and different VO contents (x = 0.1 - x = 0.4), only disk-like grains of the SBTV ceramics were observed in the scanning electron micrographs. Preferential orientation of the crystals of the SBTV ceramics was confirmed through X-ray diffraction studies. The higher dielectric constant and Curie temperature of the SBTV ceramics compared with those of strontium bismuth tantalite (SrBiTaO, SBT) ceramics are ascribe to the partial replace of Ta ions by V ions in the B sites. The Curie-Weiss law and the modified Curie-Weiss law were used to discuss the normal-type or relaxor-type ferroelectric characteristic of the SBTV ceramics. The Ta ion replaced by V ion site in SBT ceramics to form SBTV ceramics exerted a pronounced effect on the BO mode, as demonstrated by Raman spectrum results.