Effect of annealing temperature of cerium oxide nanoparticles studied by small-angle X-ray scattering

The evolution of microstructure of cerium oxide nanoparticles prepared in a sol-gel process was investigated by small-angle X-ray scattering (SAXS) measurements, in which the range of annealing temperature was from 298 K to 973 K in air. It was found that their scattering intensities increased dramatically and was proportional to h(-a) as the temperature went up to 873 K. Meanwhile, the average radius of gyration R-g increased. This suggested that these cerium oxide nanoparticles have self-similar structure behavior or mass fractal structure. When the temperature was higher than 873 K, the feature of the SAXS spectra became identical to that of the sactterers with surface fractal structure rather than the mass fractal structure.