Mössbauer and X-ray diffraction study of the influence of Mn-doping on the structure of mechanically alloyed Fe nitrides

Abstract

The evolution of mechanically alloyed Mn doped iron nitride has been investigated to determine the Mn preferred substitution site in the γ′-Fe4N nitride. X-ray diffraction and Mössbauer spectroscopy have shown segregation of α-Fe when Mn is added to the nitride. The study of phase fractions allowed us concluding that along the milling process Mn replaces Fe only in the Fe4N phase, substitution occurring at both sites I and II, but mainly at site I. Some substitution in the other Fe-N phases takes place, but it brings about only a decrease of the mean magnetic field of Fe3N with the Mn content. Hyperfine parameters of Fe4N and Fe3N are also reported.