119Sn Mössbauer study of sol–gel synthetized FexSbySn1 − x − yO2 − δ powders

119Sn Mössbauer spectroscopy was used to study Sn1 − x57FexO2 − δ and FexSbySn1 − x − yO2 − δ sol–gel synthesized ferromagnetic powders. 119Sn Mössbauer spectra of powder samples showed envelopes characteristic of a relatively broad Sn(IV) line. Small but significant differences can be found among the spectra belonging to different compositions and heat treatments. The spectra were decomposed into two doublets, one of these with unusually high quadrupole splitting was assigned to the defects playing very important role in the realisation of ferromagnetism in these materials.