XAS et XMCD aux seuils L23 de Fe et Mo dans Sr2

Electronic structure and x-ray magnetic circular dichroism of Sr2FeMoO6 : Ab initio calculations
Kanchana V, Vaitheeswaran G, Alouani M, Delin A
Phys. Rev. B 75, 220404 (2007)

Theoretical investigations of the electronic structure (see Fig. 1), x-ray absorption (XAS), and x-ray magnetic circular dichroism (XMCD) at the Fe L2,3 and Mo L2,3 edges of Sr2FeMoO6 are carried out by means of the generalized gradient approximation. The magnetic coupling between Fe and Mo is found to be antiparallel, which gives direct confirmation of ferrimagnetic ordering and settles controversies existing between the earlier experimental reports.This is also confirmed by our good agreement of the Mo L2,3 edges with experiment (see Fig. 2). Using our theoretical spectra, we recalculate the spin and orbital magnetic moments by means of the XMCD sum rules and compare the results with the direct self-consistent calculation and experiment.

Fig. 1 : Calculated spin-resolved partial density of states (DOS) of Sr2FeMoO6 at the experimental lattice constants in units of states/eV/fu (formula unit). The partial DOS of 3d-Fe are blue (continuous line), that of 4d-Mo red (dashed lines), and that of 2p-O green (dotted lines). The majority spins are represented in the positive scale part of the plot, and that of minority spins in the negative part. The DOS shows that Sr2FeMoO6 is a ferromagnetic half-metal.

Fig. 2 : Calculated XAS and XMCD spectra of Mo L2 L3 edges (full lines) as compared to the experimental results (dashed lines). We have used a FWHM of 0.5 eV to broaden the spectra.

Involved persons :

M. Alouani

In collaboration with :

V. Kanchana, G. Vaitheeeswaren, A. Delin, Department of Materials Science and Engineering, Royal Institute of Technology, 10044 Stockholm, Sweden

Dans la même rubrique :

Etude ab initio des Propriétés Electroniques et de Transport Quantique dans les Jonctions HybridesAuto-assemblage et calibration en taille des nanostructures 1D