Combustion synthesis and characterization of nanocrystalline proton conducting Sr(Ce0.6Zr0.4)0.95Yb0.05O3−δ

In this study, the nanocrystalline proton conducting Sr(Ce0.6Zr0.4)0.95Yb0.05O3−δ was successfully synthesized by an auto ignition combustion process. The stages of Sr(Ce0.6Zr0.4)0.95Yb0.05O3−δ formation and its characterization were examined using thermogravimetric and differential thermal analysis (TG–DTA), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The synthesized powders exhibit pure perovskite structure with uniform particles of size ∼14 nm. High densification of the Sr(Ce0.6Zr0.4)0.95Yb0.05O3−δ ceramics was obtained at 1450 °C, a temperature much lower than that required for the conventional solid-state reaction method. Electron probe X-ray microanalyzer (EPMA) observation further revealed that the sintered grains remain relatively small and in homogeneous distribution up to 1500 °C. In addition, the electrical properties of Sr(Ce0.6Zr0.4)0.95Yb0.05O3−δ ceramics have been determined in wet air.