Structure and magnetic properties of R2Fe17Nx compounds

We have shown that ternary rare earth nitrides of the approximate composition R₂Fe₁₇N_2.5 can be prepared by the reaction of R₂Fe₁₇ with nitrogen gas at 500°C for all members of this series. The crystal structure and lattice constants of these compounds have been determined and are discussed in terms of volume increase and nitrogen site occupation. The N₂ uptake was found to be accompanied by strong increases of the Curie temperature and room temperature magnetization. From the results it was derived that the N₂ uptake may lead to substantial changes in the RFe coupling strength.