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

Kobayashi, Masaki*; Anh, L. D.*; Hai, P. N.*; Takeda, Yukiharu   ; Sakamoto, Shoya*; Kadono, Toshiharu*; Okane, Tetsuo  ; Saito, Yuji  ; Yamagami, Hiroshi; Harada, Yoshihisa*; Oshima, Masaharu*; Tanaka, Masaaki*; Fujimori, Atsushi

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 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 estimated using the XMCD sum rules was significantly larger than that of Fe metal, indicating a significant orbital moment of Fe 3 electrons in (In,Fe)As:Be. The XMCD intensity as a function of magnetic field indicated hysteretic behavior of the superparamagnetic-like component due to discrete ferromagnetic domains. VC