Magnetism of an Fe65Mn35 alloy in the fcc/hcp phase region

Among the three possible phase structures (bcc, fcc and hep) of iron rich Fe₁₀₀-cMn _c alloys (c _Mn <40 at%), the two closed packed structures, fcc and hep, produce poor resolved and similar Mössbauer spectra. Therefore the evaluation of spectra collected on a sample (nominalc _Mn =35 at%) with coexisting fcc and hep phases only was possible with the help of the Afans’ev/Tsymbal method of “Mössbauer lines sharpening” introduced recently/1,2,3/. A comparison of the hyperfine field vs. temperature with an FeNi-Invar alloy (c _Ni =35 at%) shows a surprising similarity.