Fe‐Diluted Magnetic Alloys REIn 3− x Fe x (RE = Pr, Nd, Gd, Ho)

The phase evolution and magnetic properties of Fe doping into REIn 3 (RE = Pr, Nd, Gd, Ho) are systematically studied using X‐ray diffraction, scanning electron microscopy with energy dispersive spectrum, and magnetic measurements. Fe doping into REIn 3 induces the magnetic phase transition from paramagnetic to ferromagnetic associated with minor In separation from the cubic phase with AuCu 3 ‐type structure at room temperature. The structural stability of cubic phase is related to size effect R A and electro‐negativity difference Δ X . Cubic REIn 3– x Fe x could be stabilized in the range of 1.0602–1.0963 Å for R A and 0.380–0.420 for Δ X . Ferromagnetism of REIn 3– x Fe x might be explained as the 3d–3d interactions between Fe atoms and 3d–s–4f indirect interactions between Fe and rare earth atoms mediated by the conducting s electrons. The increase of magnetic moment for REIn 3– x Fe x could result from the partial substitution of nonmagnetic element In by magnetic element Fe in the host material through dilute doping of Fe, and thus a net moment is produced.