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

• Published in: Journal of materials science 2020-12, Vol.55 (34), p.16290-16299
• Main Authors: McQuade, Ryan R., Mardilovich, Pavel, Kumar, Nitish, Cann, David P.
• Format: Article
• Language: English
• Subjects: Barium titanates; Bismuth; Ceramics; Characterization and Evaluation of Materials; Charge transfer; Chemistry and Materials Science; Classical Mechanics; Composition; Conductivity; Conductors; Crystallography and Scattering Methods; Current carriers; Doping; Electronic Materials; Magnesium; Materials Science; Polymer Sciences; Solid Mechanics; Solid solutions
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-020-05175-4

A series of acceptor-doped ceramics based on the solid solution, (1- x )BaTiO 3 – x Bi(Zn 1/2 Ti 1/2 )O 3 (BT-BZT), where x  = 0.1, 0.2, 0.3, 0.4, were prepared via solid-state 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(Zn 1/2 Ti 1/2 )O 3 with 3 mol% Mg Ti ″ , showed the highest conductivity in this study at 1.28 mScm −1 (~ 600 °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 ~ 550 °C, ions are the dominant charge carriers (transference number, t i  = 0.91 at 735 °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 °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.