Synthesis and characterization of nano-crystalline Ce1−xGdxO2−x/2 (x = 0–0.30) solid solutions

In recent years, doped ceria is an established and promising candidate as solid electrolyte for intermediate temperature solid oxide fuel cell (IT-SOFC). In this investigation, synthesis and characterizations of nano-crystalline Gd doped ceria, (Ce1−xGdxO2−x/2, where x = 0–0.3), prepared using glycine–nitrate process (GNP) has been presented. Evolution of structural and morphological properties of nano-powders as a function of heat treatment has also been studied. The prepared samples were characterized using TG–DTA, FT-IR, Raman spectroscopy, XRD, SEM, etc. In addition, the effect of Gd content over the micro-structural properties of nano-crystalline Gd doped ceria was investigated. Raman analysis of calcined powders confirms the formation of the solid solution of Ce1−xGdxO2−x/2 instead of mixture of CeO2 and Gd2O3. The solid solutions obeyed Vegard's rule very well. Grain growth of sintered samples was observed to hinder with an increase in Gd content.

Research highlights▶ The densification of samples can be achieved at relatively lower temperatures for nano-powders prepared using the combustion synthesis. ▶ However, there is possibility of reduction of ceria during the conventional sintering scheme and the systematic evolution of the ceria as function of heat treatment is presented in this particular research.