119Sn Moessbauer and neutron diffraction investigation of β Mn-Sn solid solutions

119Sn Moessbauer and neutron diffraction measurements at room temperature indicate that the solute Sn atoms preferentially occupy the type I site. 119Sn Moessbauer measurements at 5 K on 2.5 at.% Sn and 5.0 at.% Sn solid solutions show clear evidence of magnetic order. The magnetic splitting obtained is consistent with a distribution of hyperfine fields centred at approximately 5 T. The observation of magnetic order in β-Mn alloys is possibly correlated with the expansion of the lattice. The X-ray and neutron diffraction measurements on β Mn-Sn show that the lattice expands by 0.3% for each at.% of Sn dissolved. (Auth.)