Effect of fuel type on microstructure and electrical property of combustion synthesized nanocrystalline scandia stabilized zirconia

▶ Nanocrystalline 10ScSZ was prepared using three different types of fuels. ▶ Urea and glycine gave crystalline powders but citric acid gave amorphous powder. ▶ All powders exhibited cubic phase when calcined at 800 °C for 1 h. ▶ A small fraction of the cubic phase transforms to β phase on sintering. ▶ Powder aggregates were foamy with glycine and citric acid and hard with urea. ▶ Glycine and citric acid yielded finer powder than urea. ▶ The finer grain size resulted in higher conductivity and lower activation energy. Nanocrystalline 10 mol% scandia stabilized zirconia (10ScSZ) powders were prepared by combustion synthesis using three different types of fuels (urea, glycine and citric acid). The influence of nature of fuel on phase formation, particle size and morphological characteristics was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of fuel type on electrical conductivity was also evaluated. The 10ScSZ prepared by urea and glycine was fully crystalline whereas citric acid resulted in amorphous form. The powder turned crystalline on calcination at 800 °C. Urea resulted in highly agglomerated powder whereas porous and loose agglomerates were formed with glycine and citric acid as fuels. The powder processed with urea showed higher crystallite size compared to powders processed with glycine and citric acid. The ScSZ electrolyte pellet processed with glycine and citric acid exhibited better conductivity and lower activation energy compared to the electrolyte processed with urea.