Crystallographic and magnetic properties of R.E.2(Fe,Ni)17 alloys

Crystallographic and magnetic investigations on ternary alloys with the nominal composition R.E.2(Fesub(1-x)Nisub(x))17, R.E.=Y, Dy, are reported. Solid solubility was found up to x=0.5 and 0.3 for Y2(Fe,Ni)17 and Dy2(Fe,Ni)17, respectively. Single-phase samples could only be prepared by using an increasing excess of R.E. over the stoichiometric composition, with increasing Ni content. At higher Ni concentrations, an R.E.(Fe,Ni)5 mixed crystal and α-Fe, or a γ-(Fe,Ni) alloy can be detected, depending on the nominal composition. The results of the magnetic measurements can be explained by means of a rigid-band model in analogy with the binary (Fe,Ni) alloys. The influence on the mean 3d moment of the conduction electrons contributed by the R.E. atoms is small in the mixed crystals with the Th2Ni17-type structure but strong for the binary R.E.2Ni17 compounds where a decrease of the Ni moment can be detected. The Curie temperatures increase with increasing x and show a maximum for x approximately 0.4 in the mixed crystals, Y2(Fe,Ni)17. (Auth.)