Magnetic properties and magnetocrystalline anisotropy of Nd2Fe17, Nd2Fe17X3, and related compounds

Abstract

The electronic and magnetic properties of Nd2Fe17 and Nd2Fe17X3 (X = C or N) compounds have been calculated using the first-principles density functional calculations. Among these, the nitrogen and carbon interstitial compounds exhibit all of the required properties such as a saturation moment of 1.6 T, Curie temperature of 700-750 K, however easy magnetic axis lies in the planar direction making them less attractive for permanent magnet applications. The calculated magnetocrystalline anisotropy energy is found to be -2.7 MJ/m3 for Nd2Fe17C3 and -4.7 MJ/m3 for Nd2Fe17N3. We further explored the possibility of changing the easy axis direction through La/Ce alloying at Nd site. Although the MAE is found to be smaller in magnitude for all the La/Ce alloys it still maintains planar direction.