High sinterability nano-Y₂O₃ powders prepared via decomposition of hydroxyl-carbonate precursors for transparent ceramics

High sinterability nano-Y₂O₃ powders for transparent ceramics were successfully synthesized via the decomposition of hydroxyl-carbonate precursors from spray coprecipitation. The chemical composition of the precursor was determined as Y(CO₃)(OH)·nH₂O (n = 1–1.5), and it was evolved into Y₂O₃ particles with clear facets after calcination with the assistance of sulfate. Two dispersion mechanisms, “absorption” and “intercalation,” were proposed to work together to provide the dispersion effect. Microstructural and optical characterization of powders and as-fabricated transparent ceramics was employed to evaluate the sintering behavior of powders. The nanopowders calcined at 1250 °C had weakly agglomerated morphology with the mean particle size of ~140 nm and exhibited excellent sinterability. The in-line transmittance of Y₂O₃ ceramic of 1 mm thickness that was vacuum sintered at 1800 °C for 8 h without any sintering additives reached 78.7% at 1064 nm.