Sintering and densification behavior of Mn-doped CeO2

The effect of Mn doping on sintering and densification behavior of commercial CeO2 powder has been investigated in this study. The results from both X-ray diffraction (XRD) and thermal gravimetric-differential thermal analysis methods indicate no binary compounds are formed between CeO2 and MnO2, and Mn element exists in the state of Mn2+ (i.e. MnO) in the samples sintered above 1200°C. Dilatometer measurement and scanning electron microscopy observation confirm that small amount of Mn doping reduces sintering temperature dramatically and promotes grain boundary mobility. About 1% Mn-doped CeO2 sintered at 1300°C for 2 h reaches almost full densification (>99.0% of relative density), compared with ∼96% of relative density for pure CeO2 sintered at 1525°C for 2 h, and both samples have almost the same grain size.