Theoretical study of the anisotropic hyperfine interaction of Cu atoms close to 3d impurities

The anisotropic hyperfine interaction of Cu atoms close to magnetic 3d-impurity atoms has been studied by means of self-consistent calculations of the electronic structure using the Korringa-Kohn-Rostoker Green’s-function method of band-structure calculations. In addition to our former work, dealing with the isotropic Fermi contact interaction, the spin-dipolar interaction has been investigated for the first four shells of Cu atoms around 3d impurities. Similarly to the isotropic part it is found that the normalized anisotropic interaction varies more or less linearly with the atomic number of the impurity atom. Most of the assumptions used so far for interpreting experimental NMR data can be justified by our results. By comparing with the corresponding experimental information, a very satisfying agreement is found. Based on this and additional arguments, it is concluded that the spin-dipolar contribution is by far the dominating source of the anisotropic hyperfine interaction for the impurity systems studied.