Improved densification in cold sintering of gadolinia‐doped ceria with reactive sintering aids

Abstract

This study explores a novel reactive cold sintering method for improving the density of gadolinia‐doped ceria (GDC) ceramics while reducing the annealing temperature. Instead of using deionized water as an aid in conventional cold sintering, stoichiometrically mixed Ce(NO3)3·6H2O and Gd(NO3)3·6H2O precursors were added as additives during the CSP in this study. The effects of processing parameters such as sintering temperature and additive content on the relative density of the compacts were investigated using synthesized GDC and commercial GDC powders as raw materials. The results showed that with the aid of precursors, GDC ceramics were sintered up to 90% of their theoretical densities at 850°C and up to 94% at 950°C when the synthesized nanopowder GDC was used. Additionally, the sintering mechanism was investigated, and it was found that the GDC generated by the precursor reaction effectively filled the gaps between the original particles, promoting densification of the sample after cold‐pressing.