Lattice-distortion effects on the magnetism of Mn impurities in Al and Cu

Abstract

Self-consistent calculations with the discrete variational method in the framework of local spin-density theory were performed for 43-atom embedded clusters representing a Mn impurity in Al and Cu hosts. Effects of local lattice relaxation were explored by varying the distance between Mn and the nearest-neighbor host atoms. It was found that the magnetic moment of Mn in Al is much more sensitive to local lattice distortion than Mn in Cu. At the equilibrium Mn nearest-neighbors distance, as determined by x-ray absorption fine-structure measurements, a reduction of 34% of \ensuremath{\mu} in Al is obtained, relative to the host lattice distance. Mechanisms related to the effect of the environment on \ensuremath{\mu} are discussed. The Mn 3s exchange splitting observed in x-ray photoelectron spectra is also investigated, and it is found that it may not be taken as evidence of a 3d moment in the ground state.