An α-Fe2O3 powder of nanosized particles via precursor dispersion

An alpha-Fe2O3 powder of nanosized particles has been successfully prepared by effectively dispersing the precipitated hydroxide precursor in a sodium chloride matrix. In particular, the hydroxide precursor was converted into crystalline alpha-Fe2O3 particles approximately 10 nm in size when it was mechanically activated in the sodium chloride matrix for 1 h. The subsequent calcination at 600 OC for 1 h resulted in a limited degree of coarsening in particle size while the crystallinity of alpha-Fe2O3 was further established. The effectiveness of obtaining ultrafine alpha-Fe2O3 powders by mechanical activation in the sodium chloride matrix was demonstrated by comparing the powder with those obtained via other routes, such as mechanical activation without sodium chloride as the matrix, calcination at 600 OC, and then mechanical activation in sodium chloride matrix, respectively. None of these processing routes led to a powder comparable in particle characteristics to that derived by the precursor dispersion.(b)).