Structural and magnetic study of some oxygen stabilized rare-earth-iron intermetallic compounds

A new series of oxygen stabilized intermetallic compounds was identified in sintered, pre-alloyed, rare-earth-iron powder samples. The composition of these compounds corresponds to the formula R₁₂Fe₃₂O₂, though the concentration of oxygen may, in some instances, be variable. The crystal structure of these compounds belongs to space group Im3m. Their presence has been observed in several RFeO systems, with R = Gd, Tb, Dy, Ho, Er and Y. Magnetic measurements indicate that Y₁₂Fe₃₂O_x (x ≤ 2) is ferromagnetic, whilst the compounds with R = Dy and Ho are ferrimagnetic. The magnetic ordering temperatures of these three compounds range from 180 to 265 K, with possibly higher ordering temperatures for the Gd- and Tb-containing compounds.