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 L_3,2-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 L_3,2 XANES spectra suggest the absence of mixed valence states in agreement with previous x-ray resonance scattering measurements. [ABSTRACT FROM AUTHOR]