First-principles study on stability and magnetism of NdFe_(11)M and NdFe_(11)MN for M = Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn

摘要

Recently synthesized NdFe_(12)N 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 NdFe_(12). We find that Co has a positive effect on the stability of the ThMn_(12) 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 NdFe_(11)Co greatly enhances 〈r~2〉A_2~0. This suggests that Co is a good candidate as a substitutional element for NdFe_(12)N.