The study of trivalent-dopants effect on electrical properties of the BaZr_0.7In_0.3O_3-δ system

Abstract

Perovskite BaZrO₃ and BaZr_0.7In_0.3O_3-δ (BZI) ceramics were prepared via solid-state reaction. The crystal structure, dielectric and electrical properties of these ceramics were analyzed comparatively. Rietveld analysis indicated that BaZrO₃ and BaZr_0.7In_0.3O_3-δ (BZI) have cubic symmetry with the Pm$\overline{3}$m space group. A small amount of In₂O₃ was observed in the BZI ceramic. The lattice parameter (a) decreased when a small amount of In³⁺ was added. The relative permittivity ε_r(T) and tan δ(T) of BZ and BZI ceramics behaved as plateaus that were independent of frequency and temperature in a temperature range of below 150 ̊C and 50 ̊C, respectively, which ascribed to the intrinsic dielectric properties resulting from electronic and/or ionic polarization. By increasing the temperature further, both ceramics exhibited colossal dielectric constant (CDC) behavior. Conductivity was greater with increasing temperature, which corresponded to Arrhenius behavior. Activation energies were calculated as 0.522 and 0.620 eV for the BZI and BZ system, respectively.

Keywords:

• Proton-conducting perovskite
• trivalent-doped barium zirconate
• Rietveld refinement

Additional information

Funding

This work was financially supported by King Mongkut’s Institute of Technology Ladkrabang under grant number A118-0361-005 and 2561-01-05-77.