Structural, dielectric and ferroelectric properties of Ba1-x(Bi0.5Na0.5)xTiO3 ceramics

Lead free Ba1-x(Bi0.5Na0.5)(x)TiO3 (x=0, 0.02, 0.04, 0.06, 0.08, 0.1) ferroelectric ceramics were synthesized by conventional solid state reaction technique. Sintering was done at 1200 degrees C for 2 h in air atmosphere. The final products have tetragonal symmetry with decreasing c/a ratio confirmed by X-ray diffraction analysis. The grain size varies between 300 nm to 1000 nm for x=0 to 0.1. With increase in Bi0.5Na0.5TiO3 [BNT] content, the room temperature permittivity decreases whereas the Curie temperature (T-c) increases and its highest value was found to be 155 degrees C for 10 mol% of BNT addition. The ceramics show stable and low dielectric loss characteristics. The remnant polarization (P-r) and the coercive field (E-c) increases monotonously with increase in BNT content. The highest value of 2P(r) (= 17 mu C/cm(2)) and 2E(c) (=22 Kv/cm) was obtained for x=10 mol% BNT addition. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.