Studies of Combustion Mechanochemical Reactions in Off-Stoichiometric Powder Mixtures of Fe1 − x S1 + x

The reaction between iron and sulfur powders induced by high-energy ball milling was studied as a function of milling time and the composition of starting powders Fe(1 – x) + S(1 + x), where x = –0.03, 0, 0.03, 0.05, 0.10. The reaction products were studied by using the Mössbauer spectra and X-ray diffraction analysis. The analyzed process is self-sustaining and runs for a period of time of 2–5 hours of milling. The iron powder used in this case was characterized by a particle size of 1600 mesh. The Mössbauer spectra obtained at room temperature after 2 hours of milling revealed partial sulfiding missed in the course of X-ray diffraction analysis. In all other samples, we observed a sextet (for an internal magnetic field of 21 MA/m) and a doublet (with insignificant deviations from the corresponding parameters for FeS₂). This confirms the results of X-ray phase diffraction analysis according to which FeS is the sole significant phase.