First-principles study on stability and magnetism of NdFe11M and NdFe11MN for M = Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn

Recently synthesized NdFe12N has excellent magnetic properties, while it is thermodynamically unstable. Using the first-principles method, we study the effect of substitutional 3d transition metal elements to the mother compound NdFe12. We find that Co has a positive effect on the stability of the ThMn12 structure. In contrast to Ti substitution, Co substitution does not reduce the magnetization significantly. The crystal field parameter < r(2)> A(2)(0) is nearly unchanged by Co substitution, and nitrogenation to NdFe11Co greatly enhances < r(2)> A(2)(0). This suggests that Co is a good candidate as a substitutional element for NdFe12N. Published by AIP Publishing.