SAXS study on the microstructure of Fe2O3 nanocrystal

The aim of this work is to investigate the microstructure development of Fe2O3 nanocrystal, prepared in sol–gel process, as a function of annealing temperature in air. Combined with the TEM and XRD patterns, small-angle scattering of X-rays (SAXS) reveals that the size of Fe2O3 nanocrystal increases and Fe2O3 structure changes from maghemite to hematite (γ to α) by increasing annealing temperature. SAXS also indicates that the growth of Fe2O3 nanocrystal follows fractal. When the annealing temperature is increased, fractal property of Fe2O3 nanocrystal changes from volume fractal to surface fractal, corresponding to the formation of Fe2O3 network.