Electronic structure and magnetic properties of Al-doped Fe3O4 films studied by x-ray absorption and magnetic circular dichroism.

The electronic structure and magnetic properties of Al-doped Fe3O4 films at various Al concentrations were investigated by Al and O K-edge x-ray absorption near-edge structure (XANES) and Fe L3,2-edge magnetic circular dichroism (MCD) measurements. The O K-edge XANES spectra reveal that the intensity of O 2p–Fe 3d hybridized states decreases linearly as the Al concentration increases, suggesting that nonmagnetic Al substitution reduces couplings of the O 2p with Fe 3d orbitals. The Fe L3-edge MCD spectra show that the intensities of MCD features decrease as the Al concentration increases, which suggests that Al substitution reduces the magnetic moments of Fe ions. The Fe L3,2 XANES spectra suggest the absence of mixed valence states in agreement with previous x-ray resonance scattering measurements. [ABSTRACT FROM AUTHOR]