Samples of Sm2Fe17-xCox (x = 0.5 - 3) arc-melted and subsequently annealed at a temperature 1225 K, were studied by X-ray diffraction (XRD), using the Rietveld method, coupled to Curie temperature Tc measurements. The as prepared compounds crystallize in a rhombohedral structure Th2Zn17-type. The Curie temperature increases linearly with "x" to reach 790 K for x = 3. The increase of Tc despite the low contraction of the cell volume can be explained by the strong exchange integrals JCo-Co and JFe-Co. The substitution of Co was assumed to contribute to complete the 3d sub band, reduce the negative interactions and induce the Curie temperature enhancement.
I. Nehdi, M. Abdellaoui, C. Djega-Mariadassou, H. Zarrouk
Rare earth compounds, Transition metal compounds, Crystal structure, Magnetic measurements