Syntheses, crystallographic and magnetic properties of Nd3Fe29-xCrx and other associated compounds

A systematic study of syntheses and magnetic properties of the Nd-3 Fe29-xC rx (x=4.5, 4.7, 5.0, and 5.5) compounds has been performed. The single-phas e compounds of Nd3Fe29-xCrx can be formed in the range 4.5 less than or equ al to x less than or equal to 5.5. The Curie temperature Tc, the saturation magnetization M-S at 4.2 K, the anisotropy field H-A at 4.2 K and room tem perature, and the intra-sublattice exchange coupling parameter j(FeFe) at 4 .2 K for the Nd3Fe29-xCrx compounds decrease with increasing Cr composition from x=4.5 to 5.5, respectively. Nitrogenation and carbonation, unlike hyd rogenation, result mainly in improvements of the Curie temperature, the sat uration magnetization and the anisotropy field at 4.2 K and room temperatur e for the Nd3Fe29-xCrx compounds compared with their parent compounds.