Substitution Effect of Fe Sites in Nd2Fe14B

In order to investigate the magnetic contributions of each iron site of Nd2Fe14B, the magnetic properties of Nd2 (Fe1-xMx)14B (M=Al, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Pt) were measured, and the preferential occupation of Fe sites by M atoms was studied by Mossbauer spectroscopy. The Mossbauer spectra were analyzed by a method of our own devising, which takes into account the effect of the environment and the degree of preference of each Fe site. These analyses revealed that the Curie temperature Tc increases with increases in the lattice parameter c accompanying preferential substitution of M atoms at the k1 and j1 sites, but decreases when j2 site is preferentially occupied by M atoms. It seems that the ferromagnetic interaction between Fe planes increases with the lattice expansion and decreases as j2 site is occupied by M atoms. On the other hand, Ts decreases when there is preferential substitution at c site. This fact suggests that Ts is related to the interaction between Fe and Nd atoms.