X-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism measurements were performed at the Ni and Fe L2,3 absorption edges for NixFe4-xN(x=1 and 3) epitaxial films. Spectral line-shape analysis and element-specific magnetic moment evaluations are presented. Shoulders at approximately 2 eV above the Ni L2,3 main peaks in the XAS spectrum of Ni3FeN were interpreted to originate from hybridization of orbitals between Ni 3d at face-centered (II) sites and N 2p at body-centered sites, while such features were missing in NiFe3N film. Similar shoulders were observed at Fe L2,3 edges in both films. These results indicate that the orbitals of Ni atoms did not hybridize with those of N atoms in the NiFe3N film. Hence, Ni atoms preferentially occupied corner (I) sites, where the hybridization was weak because of the relatively long distance between Ni at I sites and N atoms. The relatively large magnetic moment deduced from sum-rule analysis of NiFe3N also showed a good agreement with the presence of Ni atoms at I sites.
ASJC Scopus subject areas
- Materials Science(all)
- Physics and Astronomy (miscellaneous)