Ferromagnetic alloys of manganese and tin have been used to obtain large internal magnetic fields at the tin nuclei. The resultant Zeeman splittings of the two low levels of ${\mathrm{Sn}}^{119}$ have been measured by observing the hyperfine spectra in the resonant absorption of the 24-kev radiation of ${\mathrm{Sn}}^{119}$. In ${\mathrm{Mn}}_4$Sn an internal field of roughly 40 koe was found. In this field the splitting of the ground state was observed but that of the excited state was unresolved. In ${\mathrm{Mn}}_2$Sn an internal field of about 190 koe was produced. In this field additional structure was obtained which was attributed to the splitting of the excited state. The measured splitting gives a value of (0.78±0.08) nm for the magnetic moment of the excited state.

• Received 5 August 1960

DOI:https://doi.org/10.1103/PhysRev.120.2211