Promoting densification and grain growth of BaCe0.65Zr0.2Y0.15O3-

BaCe0.65Zr0.2Y0.15O3-delta (BCZ20Y15) has raised great interest due to its good protonic conductivity and chemical stability. However, the sintering of the material is considerably challenged by its refractory nature. In the current work, almost fully densified single-phase BCZ20Y15 with grain sizes exceeding 10 mu m was successfully fabricated by sintering at 1500 degrees C by using calcined powders consisting of naturally separated perovskite phases and 0.5 wt % NiO. The role of NiO as sintering aid was elucidated by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and Atom Probe Tomography (APT) methods, concerning global and local material composition. Furthermore, the mechanism leading to the promoted densification and grain growth is elucidated based on current experimental results and a comprehensive review of the literature.