Synthesis and characterization of nanocrystalline yttrium oxide prepared with tetraalkylammonium hydroxides

Controlled chemical precipitation of yttrium hydroxynitrate has been used to synthesize nanocrystalline yttrium oxide powders with high thermal stability. The type of base employed as the precipitating agent has a significant effect on the properties of the yttrium oxide product. Precipitation with tetraalkylammonium hydroxides was shown to produce a much finer-grained product than a conventional ammonium hydroxide synthesis route. This is attributed to the higher pH that can be achieved with tetraalkylammonium hydroxides, as well as the ability of tetraalkylammonium cations to inhibit precipitate particle growth by lowering the rate of diffusion of soluble precursors to the particle surface.