Magnetic and structural characterization of Nd5 Fe17

A new stable compound in the Nd-Fe system has been identified as Nd 5 Fe17. It is identical with phases formerly described in the literature as being stabilized by oxygen. Although oxygen may be present as an impurity, it does not play essential role. The crystal structure belongs to the hexagonal space group PG3/mcm, with a = 2.0214(8) nm and c = 1.2329(8) nm, and with 12 formula units per unit cell. This compound is a ferromagnet with Tc = 503 K and magnetization 162 emu/g at 4.2 K. Moessbauer spectra have been measured at different temperatures and fitted with five Fe sites yielding an average Beff = 30.7 tesla at T = 10 K, from which an average Fe moment of 2.12 Bohr magnetons is deduced. X-ray powder diagrams from magnetically aligned samples suggest basal anisotropy. (author)