Magnetic properties of interstitially modified Nd3(Fe,Ti)29Xy compounds (X=H, C, and N)

The effects of light atom intercalation on the magnetic properties of the monoclinic compound Nd3(Fe,Ti)29 have been studied by Mössbauer spectroscopy and thermogravimetric analysis. Maximum contents of 4 nitrogen atoms and 6 hydrogen atoms per formula unit have been achieved, consistent with structural calculations. The associated lattice expansion ranges from 2% in the hydride to 6.5% in the nitride. Attempts to introduce carbon were unsuccessful as the material decomposed rapidly during the reaction. Both hydrogen and nitrogen additions lead to substantial increases in the magnetic ordering temperature, but only the nitrogen leads to an increase in the iron moment.