Fe-doped TiO2 prepared by mechanical alloying

The effect of different milling conditions on the formation of Fe-doped TiO2 powders by mechanical alloying was investigated by Mossbauer spectrometry. The milling conditions investigated were ball to powder weight ratio, milling time, rotation velocity of supporting disc, and the type of starting reactive iron and its concentration. X-ray diffraction shows that high energy mechanical milling of undoped anatase TiO2 induce the anatase to rutile phase transformation via high pressure srilankite. Mossbauer spectra for the majority of the doped samples were decomposed into one sextet and one or two doublets. The sextets was attributed to the presence of alpha-Fe or hematite impurities. The doublets were assigned to Fe3+ incorporated in the TiO2 structure, and to the Fe2+ located either at the surface or the interstitial sites of TiO2. A greater incorporation of Fe in the TiO2 structure was observed when samples were prepared from hematite instead of alpha-Fe.