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arXiv · 1405.5130

Spin and orbital magnetic moments of Fe in the $n$-type ferromagnetic semiconductor (In,Fe)As

M. Kobayashi·L. D. Anh·P. N. Hai·Y. Takeda·S. Sakamoto·T. Kadono·T. Okane·Y. Saitoh·H. Yamagami·Y. Harada·M. Oshima·M. Tanaka·A. Fujimori
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Abstract

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 $L_{2,3}$ 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 ($M_\mathrm{orb}$/$M_\mathrm{spin}$) 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 $M_\mathrm{orb}$/$M_\mathrm{spin}$ implies that the Fe $3d$ shell is more than half-filled, which arises from the hybridization of the Fe$^{3+}$ ($d^5$) state with the charge-transfer $d^6\underline{L}$ states, where $\underline{L}$ 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.

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M. Kobayashi, L. D. Anh, P. N. Hai, Y. Takeda, S. Sakamoto, T. Kadono, T. Okane, Y. Saitoh, H. Yamagami, Y. Harada, M. Oshima, M. Tanaka, A. Fujimori. 2014-05-20. Spin and orbital magnetic moments of Fe in the $n$-type ferromagnetic semiconductor (In,Fe)As. https://doi.org/10.1063/1.4890733

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