Dielectric and ferroelectric properties of (1 − x)BaTiO3–xBi0.5Na0.5TiO3 ceramics

Lead-free (1 − x)BaTiO3–xBi0.5Na0.5TiO3 (x = 0.01, 0.02, 0.05, 0.1, 0.2, 0.3) ferroelectric ceramics were fabricated by the conventional ceramic technique. Sintering was made at 1200 °C for 2–4 h in air atmosphere. The crystal structure was investigated by X-ray diffraction. The dielectric and ferroelectric properties were also studied. Room temperature permittivity was found to decrease as Bi0.5Na0.5TiO3 (BNT) content increases. Only the sample with 0.3 mol BNT was found to have relaxor behaviour. The Tc shifted slightly only for BNT addition lower than 0.1 mol. The highest Tc (about 150 °C) was obtained for 0.2 mol BNT addition. The remanent polarization, Pr, decreases whereas the coercive field, Ec, increases monotonously as the BNT content increases.