“…Considering the low concentrations of Fe atoms doped into the host semiconductors, it appears necessary to think about the inhomogeneous distribution of Fe atoms on the nanoscale, or the spinodal nanodecomposition [6], because both superexchange and double-exchange interactions are short-ranged. In fact, previous XMCD measurements on (In,Fe)As:Be [30] and (Al,Fe)Sb [38] thin films grown by the molecular beam epitaxy methods revealed that there exist nanoscale ferromagnetic domains even at room temperature much above the macroscopic T C , the origin of which was attributed to the nanoscale Fe concentration fluctuation. Furthermore, the nanoscale Fe-rich lamellae-like structures were recently observed in (In,Fe)As thin films prepared by the pulsed laser melting method [39].…”