Electrospray atomization of high-concentration (similar to 400 g/L) ch
emical precursor solutions was applied to the synthesis of yttria powd
ers, Conditions mere found which led to high-quality powders, composed
of dense, spheroidal, submicrometer, and nanocrystalline oxide partic
les, The precursor solutions were hydrated yttrium nitrates dissolved
in n-propyl alcohol at concentrations ranging from 44.1 to 455 g/L. El
ectrospray atomization produced submicrometer precursor droplets which
were dispersed in air and carried through an electric furnace for the
rmal decomposition at 500 degrees C for several seconds residence time
, X-ray powder diffraction patterns indicated the expected cubic phase
, Transmission electron micrographs showed that the particle structure
varied with solution composition, ranging from hollow, inflated spher
es for 6-hydrated nitrates to dense spheroids for 5-hydrated nitrates,
The use of 6-hydrated nitrates in the solutions appeared to form part
icle surfaces which mere impermeable to alcohol vapor evolved during t
hermal decomposition, leading to hollow, inflated spheres.