Oxidation of silicon from an Fe–6 at% Si alloy

• This paper studies the oxidation of Fe–6 at% Si alloy.
• Oxidation has been done at 570 °C in 10−2 mbar for 300 h.
• Silicon has been oxidized from the α-Fe–Si solid solution.
• Wüstite, magnetite, and fayalite were detected.

Silicon has been oxidized from the α-Fe–Si solid solution during isothermal resistivity measurement at 570 °C. Measurements have been done in 10−2 mbar for 300 h. Mössbauer spectra showed that the α-FeSi solid solution, which is represented three sextets in Mössbauer spectra, was replaced by the pure iron (one sextet) after 168 h of heat treatment. Three new phases were obtained in the spectra representing wüstite (FeO), magnetite (Fe3O4) and fayalite (Fe2SiO4). These results were confirmed by X-ray and electron microscope measurements.