The effect of Zr addition on the formation and structural properties of 3:29 compounds in the Fe-Nd-Ti-Zr system

A new series of 3:29 compounds in the Fe–Nd–Ti–Zr quaternary system were synthesized successfully. The formation and structural properties were studied by means of powder x-ray and powder neutron diffraction. The results reveal that only a small amount of Zr content can exist in the 3:29-type compounds in the Fe–Nd–Ti–Zr quaternary system. Higher Zr content induces the formation of rhombohedral Th2Zn17-type phase. In the structures of 3:29-type compounds, the Zr content partially substitutes for Nd and enters the 2a and 4i crystallographic sites exclusively. Upon Zr substitution, the lattice parameters a, b, c and the unit cell volumes V of (Nd,Zr)3(Fe,Ti)29 compounds decrease monotonically and their intrinsic magnetic properties, including the Curie temperature and saturation magnetization, lessen as well.