Nanocrystalline scandia-doped zirconia (ScSZ) powders prepared by a glycine-nitrate solution combustion route

Nanocrystalline scandia doped zirconia (ScSZ) powders were synthesized by a solution combustion route using glycine, zirconyl nitrate and scandia as the starting materials. The properties of the as-synthesized powders are strongly influenced by the molar ratio of glycine-to-nitrate (g/n), where with the g/n ratio increasing from 0.14 to 1.12, the crystallite sizes of the powders decrease from 15.9 to 7.9 nm. 11ScSZ powders of specific surface areas up to 29 m²/g can be obtained through adjusting the initial g/n to 0.56 or greater. Incorporation of an appropriate amount of PEG dispersant into the starting solution can reduce the tendency of hard agglomeration formation. Investigations showed that powders from start solutions with the PEG incorporation have better sinterability than that of powders without the initial PEG incorporation, e.g., with the incorporation of 1.5 wt.% PEG dispersant in the starting solution, the resultant powders can be sintered to over 96% of theoretical density at 1200 °C, which is nearly 100 °C lower than that of powders without the initial PEG incorporation.