Study of relaxor behavior in a lead-free (Na0.5Bi0.5)TiO3-SrTiO3-BaTiO3 ternary solid solution system

Abstract

In this work, single phase lead-free (0.8-x)(Na0.5Bi0.5)TiO3-0.2SrTiO(3)-xBaTiO(3) (NBT-ST-BT) ceramics were prepared by conventional solid state reaction method. The effect of BT on the structure and on the dielectric and ferroelectric properties of NBT-ST-BT were investigated. A structural transformation from pseudo-cubic to tetragonal along with possible phase coexistence was witnessed as the BT content was increased. A diffuse phase transition with considerable frequency dispersion in the dielectric response and slim P-E loops evidenced strong relaxor behavior for the ternary system at higher compositions of BT. An analysis of the frequency dependent T-m, according to V-F and Power law indicated substantial interaction between the polar nano-regions and relatively broad distribution of freezing temperatures. The study of the dielectric constant at much higher and lower temperatures than T-m in the range of Burn's temperature (T-B) to freezing temperature (T-f) to provide useful information about the growth rate of polar nano-regions and their interactions for a better understanding of the relaxor behavior exhibited by the present ternary system. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved