Relationship between Crystal Structures and the Relaxor Property of SrBi2(Ta2–xVx)O9 Ceramics

Here, V 2 O 5 was used to substitute Ta 2 O 5 in SrBi 2 Ta 2 O 9 (SBT) and SrBi 2 (Ta 2- x V x )O 9 (SBTV) ceramics were formed. This study revealed that the substitution of Ta 2 O 5 by V 2 O 5 enhances the maximum dielectric constant (ε m ), increases the transition temperature, and reduces the sintering temperature of SBT ceramics. The diffraction intensity of c -axis-preferred orientation of SBTV ceramics increases with the increase in V 2 O 5 concentration and sintering temperature. Disk-type grains were observed in the SBTV ceramics at higher sintering temperatures. By the Curie-Weiss law and modified Curie-Weiss law, the phase transitions of the SBTV ceramics were discussed. The dielectric properties of SBTV ceramics revealed that the relaxor-type ferroelectric characteristics became more obvious than the normal-type ferroelectric characteristics at high V 2 O 5 concentrations and sintering temperatures. Raman spectroscopy was successfully used to study the lattice vibrational modes and structural transitions of SBTV ceramics. The spectra proved that as V 2 O 5 was added to SBTV ceramics the octahedral TaO 6 and VO 6 structures exhibited a high frequency mode.