Electrical properties of Na1/2Bi1/2TiO3–BaTiO3 ceramics

Lead-free Na1/2Bi1/2TiO3–BaTiO3 piezoelectric ceramics with perovskite structure were studied. The piezoelectric properties of (1−x)Na1/2Bi1/2TiO3–xBaTiO3 (x=0.02, 0.04, 0.06, 0.08, 0.10) ceramics were reported and their piezoelectric properties reach extreme values near the MPB (about x=0.06). Influences of nonstoichiometry and doping on the structures and piezoelectric properties of (Na1/2Bi1/2)0.92Ba0.08TiO3 ceramics were further studied. The relationship between piezoelectric constant and depolarization temperature of nonstoichiometric and doped ceramics was also investigated. It was found that in most of Na1/2Bi1/2TiO3–BaTiO3 ceramics studied, their depolarization temperatures were much lower than maximum temperatures of dielectric constant–temperature curves; the origin of this phenomenon was discussed.