Journal of the American Ceramic Society · 2011 · 14 citations · 35 references
In this work, spark plasma sintering ( SPS ) of 10 mol% CeO 2 ‐doped ZrO 2 nanocrystalline powders, obtained by a two‐step synthesis procedure, allows the preparation of fully densified nanostructured ceramics. The CeO 2 –ZrO 2 powders with particle size below 100 nm are obtained after CeO 2 deposition on hydrothermally synthesized ZrO 2 particles by the impregnation method. Tetragonal CeO 2 –ZrO 2 ceramics are obtained when sintering at 1200°C without holding time. A graded material containing tetragonal, monoclinic, and pyrochlore phases are obtained when sintering at 1200°C and for 5 min holding time. This is explained in terms of the gradual reduction of Ce 4+ to Ce 3+ species by carbon in the graphite environment during SPS . With the successful combination of the stabilizer coating technique and SPS , we achieve not only the stabilization of the tetragonal phase in the ceramics, but also good control of the grain size, by producing nanostructured ceramics with 40–70 nm grain sizes.
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