Electronic structure and magnetic properties of R2Fe17Nx

The author reviews the study of magnetism in R₂Fe₁₇ compounds based on self-consistent, spin-polarized electronic-structure calculations. These studies have been carried out on Y₂Fe₁₇ compound, a prototype R ₂Fe₁₇ system. Calculations show that the nitrogenation of R₂Fe₁₇ compounds produces the following changes in their magnetic properties: the magnetic moments of the Fe atoms in the vicinity of N atoms decrease, due to their overlap with the N atoms; and the magnetic moments of the Fe atoms away from N atoms increase due to the decrease in their overlap caused by the lattice expansion. This effect increases the interatomic exchange interactions among these atoms, thereby almost doubling the Curie temperature, and there is an overall increase in the total magnetization upon nitrogenation