A study of the ferromagnetic behavior of Nd 16 Co 76– x Ru x B 8 alloys

The structural and magnetic properties of the tetragonal 2:14:1 hard magnetic phase ( ϕ ) were investigated in Nd 16 Co 76– x Ru x B 8 alloys. The results indicated that Ru substitution does not harm the formation of ϕ in Co‐rich alloys. An antiferromagnetic Co–Ru coupling is concluded. The cell volume initially decreases with the Ru substitution. The coercivity is enhanced and reaches a maximum at the composition where the saturation magnetization has the lowest value. The Curie temperature as well as the mean magnetic moment decrease with increasing Ru concentration. With the increase of the Ru concentration the unit‐cell volume increases. A ferrimagnetic ordering is predicted at higher Ru concentrations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)