Structural and magnetic analysis of the transformation of Sn-doped magnetite to Sn-doped hematite by mechanical milling

Spinel-related Sn-doped Fe3 O4 has been ball milled for different times up to 35 h. Milling was found to transform the material to corundum-related Sn-doped α- Fe2 O3. The influence of the milling time, the crystallite size, and the cationic distribution on transformation process is being analyzed with x-ray diffraction, Mössbauer spectroscopy, and magnetic measurements. The relatively fast spinel-to-corundum structural transformation observed is associated with more Fe3+ ions being reduced to Fe2+ due to doping with Sn4+ ions.