Electrical conductivity and chemical stability of BaCe 0·8-xAxGd0·2O 3-δ (A = In, Zr, Ta; x = 0, 0·1) ceramics

Abstract

BaCe0·8-xAxGd0·2O 3-δ (A = In, Zr, Ta; x = 0, 01) ceramics were synthesized by solid-state reaction method. Microstructure and electrical properties of BaCe0.8-xAxGd0·2O3-δ ceramics were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and complex impedance analysis at intermediate temperatures of 573-1073 K in different atmospheres. BaCe 0·8Gd0·2O3-δ, BaCe 0·7In0·1Gd0·2O 3-δ and BaCe0·7Zr0·1Gd 0·2O3-δ ceramics exhibit a single cubic perovskite structure. BaCe0·7In0·1Gd 0·2O3-δ ceramic has the highest conductivity of 4·6 × 10-2 S·cm-1 in air at 1073 K. BaCe0·7In0·1Gd0·2O 3-δ· and BaCe0·7Zr 0·1Gd0·2O3-δ ceramics exhibit an excellent chemical stability against boiling water. Indium is a suitable doping element to promote the sintering densification and to enhance both electrical conductivity and chemical stability of Gd-doped BaCeO 3 at operating temperatures. © Indian Academy of Sciences.