Sintering kinetics of samarium doped ceria with addition of cobalt oxide

The sintering kinetics of samarium doped ceria (SDC) with addition of 5 mol% cobalt oxide is investigated by means of stepwise isothermal dilatometry (SID).We find that the isothermal shrinkage data from SID could be well analyzed to get kinetic parameters according to the empirical rate equation developed by Makipirtti–Meng,d⁢Yd⁢t=n⁢k(T)Y(1−Y)(Y1−Y)1nwhere Y is the fractional volume shrinkage during sintering process and n is a dimensionless exponent. The apparent activation energy ΔE values obtained for temperature ranges of 800–850 °C, 900–1000 °C and 1050–1150 °C are 66.4 kJ/mol, 467.7 kJ/mol and 71.8 kJ/mol, respectively. Correspondingly, the exponent n values for the three temperature ranges are also different. The mechanisms of the sintering process at various stages are discussed based on the parameters obtained associated with microstructure observation.