Structure and electrical properties of (Na0.5Bi0.5)(1-x)BaxTiO3 piezoelectric ceramics

(Na0.5Bi0.5)(1-x)BaxTiO3 ceramics were synthesized by the citrate method and their structure and electrical properties were systematically investigated. The results of X-ray diffraction analysis revealed a MPB composition range of x=0.06-0.10 for (Na0.5Bi0.5)(1-x)BaxTiO3 system at room temperature. It was found that the piezoelectric and ferroelectric properties of (Na0.5Bi0.5)(1-x)BaxTiO3 compositions near the MPB are rather sensitive to the phase composition and reach preferred values at x = 0.07, where the relative content of the tetragonal phase is substantially higher than that of the rhombohedral phases. (Na0.5Bi0.5)(1-x)BaxTiO3 ceramics present a decrease diffusive factor (delta) with increasing BaTiO3 content, implying a degradation of the relaxor feature and a transition from relaxor ferroelectrics to normal ferroelectrics. (c) 2007 Elsevier Ltd. All rights reserved.