Synthesis and Characterization of BaTiO3-(Bi0.5Na0.5)TiO3 Solid Solution Based Dielectric Ceramics

(1-x)BaTiO3-x(Bi0.5Na0.5)TiO3 solid solutions (x <= 0.12) with high paraelectric-ferroelectric transition temperature were prepared by combining BaTiO3 with (Bi0.5Na0.5)TiO3 through solid-state reactions. All X-Ray diffraction (XRD) patterns show a single perovskite phase. The c/a ratio calculated from XRD results goes up with increasing BNT content. A diffused phase transition is observed, which is mainly ascribed to composition fluctuations. Raman spectra of the solid solutions show significant peak broadening as compared with that of pure BaTiO3. The mode [A1(TO)] around 260cm(-1) disappeared when the doping content reached 8 mol%. The structures underwent a transformation from tetragonal phase to cubic phase as the rise of temperature. No Raman mode corresponding to orthorhombic phase was detected at low temperature. The dielectric properties of Nb-doped BTBNT ceramics were also investigated. With the addition of 2.0 mol% Nb2O5, 0.9BT-0.1BNT ceramic sample almost satisfied the X9R specification.