Anisotropic hfs Interactions in Ferromagnets from Mössbauer Effect Studies

The anisotropy of the magnetic hyperfine interaction in ferromagnetic Zr${\mathrm{Fe}}_2$ has been demonstrated with the Mössbauer effect. It is suggested that such anisotropy is responsible for the failure to observe domain-wall enhanced NMR in similar materials. It may also account for the failure to detect the NMR of iron atoms with impurity neighbors in dilute ferromagnetic alloys. These atoms are easily seen in Mössbauer effect studies.