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

Lead free Ba1−x(Bi0.5Na0.5)xTiO3 (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 °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 (Tc) increases and its highest value was found to be 155 °C for 10 mol% of BNT addition. The ceramics show stable and low dielectric loss characteristics. The remnant polarization (Pr) and the coercive field (Ec) increases monotonously with increase in BNT content. The highest value of 2Pr (=17 μC/cm2) and 2Ec (=22 Kv/cm) was obtained for x=10 mol% BNT addition.