Chemical stability and electrical conductivity of BaCe_0.4Zr_0.4Gd_0.1Dy_0.1O_3−δ perovskite

A proton-conducting BaCe_0.4Zr_0.4Gd_0.1Dy_0.1O_3−δ (BCZGD) perovskite is fabricated via a wet chemical route using precursors including Ba(NO₃)₂, Ce(NO₃)₃·6H₂O, ZrO(NO₃)₄·6H₂O, Gd(NO₃)₃·6H₂O, and Dy(NO₃)₃·5H₂O. The synthesis process involves the dissolution of relevant precursors and glycine in deionized water at proper molar ratios. Subsequently, the mixture undergoes a heat treatment at 1300 °C for 10 h in air to form the perovskite powders. The as-synthesized BCZGD powders are filtered and pressed at 440 MPa, following by a sintering at 1450 °C for 24 h in air to render a free-standing proton-conductive disk with a thickness of 850 μm. Material characterization including scanning electron microscopy (SEM), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), and electrical conductivity measurements are performed. The electrical conductivity of the BCZGD sample is recorded at 1.93×10⁻³ S cm⁻¹ at 700 °C in a humid hydrogen atmosphere with an activation energy of 0.41 eV. TGA results confirm chemical stability of the BCZGD against carbon dioxide without any decomposition.