Impedance study of SrBi2Ta2O9 and SrBi2(Ta0.9V0.1)2O9 ferroelectrics

This paper reports the electrical impedance properties of strontium bismuth tantalates (SBT) and strontium bismuth tantalate vanadate (SBTV) ferroelectric ceramics. AC impedance analysis was used to study the influences of vanadium doping and post sintering annealing on the microstructure and electrical properties. It was found that the vanadium doping resulted in the formation of fine-grained microstructure and an appreciable increase in dielectric constants, and Curie temperature. Post sintering annealing led to an increase in dielectric constants, but a reduction in dc conductivity. Possible mechanisms of the influences of vanadium doping and post sintering annealing on the electrical properties are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.