Determination of crystallite size of superfine zirconia powders as a function of calcination temperatures

Primary particle size or crystallite size are determined for chemically coprecipitated superfine zirconia powders with TEM (transmission electron microscopy), XRD-LB (X-ray diffraction-line broadening), BET (a method of specific surface area measurement) and SAXS (small angle X-ray scattering) techniques. The XRD-LB method was used with careful selection of diffraction peaks and a Rachinger correction was made to diminish the effect of K_α1 and K_α2 peaks overlapping. The SAXS technique is new for the particle size measurement of superfine zirconia ceramic powders and can be used to determine the size distribution in the nanometer range from about 20 to 200 nm, but the experimental procedure is tedious and the result may be affected by the stronger agglomeration of the primary particles. By the determination of the crystallite size it was found that the crystallites are equivalent to the primary particles in practice and the crystallites grow larger when calcination temperature increases. The results obtained with the four methods are comparable and supplemental to each other, the SAXS method, especially, can give useful particle size distributions at relative low calcination temperatures.