Carbonate Associated with Hydroxide Sol‐Gel Processing of Yttria:. An Infrared Spectroscopic Study

Yttrium hydroxide gel was dried by five techniques to study their influences on the sintering behavior of yttria. Dried precursors, calcined and sintered oxides, and the initial gel were examined via Fourier transform infrared photoacoustic and/or attenuated total reflection spectroscopies. Carbonate was found to be in unidentate coordination to surface yttrium on both the dried hydroxide precursor and calcined oxide particles. An inverse correlation was found between the normalized surface carbonate concentration (carbonate concentration (wt%)/surface area (m 2 /g) of precursors and calcined oxides and the density of their corresponding sintered bodies. Carbonate affects sintered density during the calcination and sintering steps.