A significant enhancement in sintering activity of nanocrystalline Ce0.9Gd0.1O1.95 powder synthesized by a glycine-nitrate-process

Abstract

Using a glycine nitrate process (GNP), nanocrystalline GDC powder has been successfully prepared that can be sintered at 1200 ℃ to a relative density of 97% which is a significantly lower sintering temperature compared to that of conventional ceria-based electrolytes prepared by traditional solid state techniques. The effect of the glycine content on the particle size, morphology, and sintering behavior has been studied by changing the glycine-to-nitrate (G/N) ratio during the combustion synthesis. A range of techniques including thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), specific surface area determination (BET), particle size analysis (PSA) and scanning electron microscopy (SEM) were employed to characterize the GDC powders prepared. From the dilatometric studies, it is observed that the GDC powders prepared with a G/N ratio 0.55 show superior sintering activity compared to GDC powders prepared with a lower G/N ratio. A sintered GDC sample showed an ionic conductivity of 2.01 × 10−2 S/cm at 600 ℃ in air.