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Free keywords:
ternary nitrides; nitridomanganates; XAS; rare earth; electronic state
Abstract:
The X-ray absorption spectroscopy at the Ce-M-4.5, Ce-L-3, Mn- L-2,L-3 and N-K thresholds was used to study the electronic and magnetic structure of the recently obtained Ce-2[MnN3]. Manganese is found to be in a state similar to that in eta- Mn3N2, with strong covalency between Mn and N. The multiple peaked structure in the Ce-M-4.5 and Ce-L-3 XAS spectra indicates that the valence state of cerium in Ce-2[MnN3] is only slightly lower than that found in CeO2 containing Ce-IV with a strong covalent mixture between Ce 4f and ligand 2p states. By simulating the Ce-L-3 XAS spectrum using a simplified Anderson impurity model the 4f occupancy was found to be 0.52 for Ce-2 [MnN3] compared to 0.49 for CeO2 in the ground state. (C) 2002 Elsevier Science B.V. All rights reserved.
