Sintering behavior of M0.25Ce0.75O1.875 (M=Dy, Gd) ceramics fabricated using pulsed electric current sintering method

Pulsed electric current sintering (PECS) method has been examined for fabrication of dense doped CeO2 sintered bodies. But high pressure (1 GPa) or long time post sintering (>20h) is required in this method. To use this method for development of high quality solid electrolyte in solid oxide fuel cells, the simple PECS process without high pressure or long time post sintering should be developed. In the present study, we examined the influence of particle morphologies and heating rate on PECS behavior. M0.25Ce0.75O1.875 (M=Dy, Gd) powder was prepared by an ammonium carbonate co-precipitation method at 75C. The relative density of doped CeO2 PECS specimen increased with an increase of heating rate. The densification behavior of PECS specimen was improved using round shaped particles. It is found that dense PECS specimen (>93% of theoretical density) can be fabricated using nano-size round shaped particles and high heating rate more than 900C/min.