Electronic structure of Mn impurities in noble metals

Abstract

Various electron-spectroscopy techniques are used to determine the electronic structure of Mn impurities in Ag and Cu. The spectral distributions of both minority- and majority-spin impurity d states are determined experimentally and compared to model calculations considering the photoemission matrix elements. The exchange and Coulomb integrals and energetic positions of the impurity d states as well as the impurity-host d-s and d-d hybridizations are determined. We find that the impurity minority-spin states are quite wide and lie close to the Fermi level, which raises questions concerning the validity of the use of a Kondo Hamiltonian to determine the low-energy scale properties. In addition, the hybridization of the majority-spin states with the host d band is larger, causing these to delocalize, whereas the magnetic moment remains localized. This large hybridization can introduce new exchange mechanisms not foreseen in conventional models.