Conduction properties of acceptor-doped BaTiO3-Bi(Zn1/2Ti1/2)O3-based ceramics

A series of acceptor-doped ceramics based on the solid solution, (1-x)BaTiO3-xBi(Zn1/2Ti1/2)O-3 (BT-BZT), where x = 0.1, 0.2, 0.3, 0.4, were prepared via solidstate synthesis to investigate the effect of doping and BZT content on conduction properties. Impedance spectroscopy measurements showed an increase in conductivity through acceptor doping with Mg on the Ti-site (Mg-Ti ''). Ceramics of the composition, 0.80BaTiO(3)-0.20Bi(Zn1/2Ti1/2)O-3 with 3 mol% Mg-Ti '', showed the highest conductivity in this study at 1.28 mScm(-1) (similar to 600 degrees C), an order of magnitude improvement over the stoichiometric composition. Variable pO(2) impedance measurements revealed p-type conductivity in the grain while EMF measurements showed that above similar to 550 degrees C, ions are the dominant charge carriers (transference number, t(i) = 0.91 at 735 degrees C). Similarly, all 3 mol% Mg-doped compositions above x = 0.1 were primarily ionic conductors with transference numbers above t(i) = 0.79 (735 degrees C). X-ray diffraction data showed a pseudocubic primary phase for all samples with evidence of additional impurity phases accompanying samples with 3 mol% Mg-Ti '' or greater.