Effect of thermal treatment in vacuum on Fe-doped SnO2 powders

A sample of 10 at% Fe-doped SnO2 powder was prepared by mechanical alloying and then thermally treated at 773 K in vacuum. The fit of the diffraction patterns and X-ray absorption spectroscopy measurements revealed that the as milled sample was pure doped rutile. Fe dissolved into SnO2 was found in Fe2+/Fe3+ ionic valence with mainly paramagnetic behavior. After the thermal treatment all techniques indicate the formation of the ternary Sn0.36Fe2.64O4 spinel phase, which is responsible for the observed ferromagnetism.