Final-stage sintering behavior of Fe-doped CeO2

The samples with Fe/Ce atomic ratios ranging from 0 to 3% were prepared via a ball-milling process from commercial powders (i.e. Fe2O3 and CeO2). A small amount of Fe doping (<1%) promotes the densification rate of ceria ceramics and increases the grain growth remarkably. Over 99.0% of relative density (RD) can be obtained for the 0.5% Fe-doped CeO2 sintered at 1300 °C in 1 h, while pure CeO2 has only 82% RD under the same sintering condition. The results from grain–growth kinetics study indicate that the grain growth exponent, n, and activation energy, Q, are 3 and 731±61 kJ mol−1 for pure CeO2, 4 and 590±50 kJ mol−1 for the 0.5% Fe-doped CeO2, respectively. Based on the present and previous work, an explanation on why the Fe doping results in the enhanced densification rate and rapid grain growth of ceria based ceramics is presented and discussed.