Spin And Orbital Magnetic Moments Of Fe In The N-Type Ferromagnetic Semiconductor (In,Fe) As

The electronic and magnetic properties of Fe atoms in the ferromagnetic semiconductor (In,Fe) As codoped with Be have been studied by x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) at the Fe L-2,L-3 edge. The XAS and XMCD spectra showed simple spectral line shapes similar to Fe metal, but the ratio of the orbital and spin magnetic moments (M-orb/M-spin) estimated using the XMCD sum rules was significantly larger than that of Fe metal, indicating a significant orbital moment of Fe 3d electrons in (In,Fe) As: Be. The positive value of M-orb/M-spin implies that the Fe 3d shell is more than half-filled, which arises from the hybridization of the Fe3+ (d(5)) state with the charge-transfer d(6)(L) under bar states, where (L) under bar is a ligand hole in the host valence band. The XMCD intensity as a function of magnetic field indicated hysteretic behavior of the superparamagnetic-like component due to discrete ferromagnetic domains. (C) 2014 AIP Publishing LLC.