Influence of Aluminum and Hydrogen on the Properties of Sm2Fe17

Cast, homogenized, and hydrogenated alloys based on intermetallic compound Sm2Fe17 with replacement of iron by aluminum to concentrations of 8.9, 17.9, 26.8, and 35.8 at % Al are investigated by the methods of X-ray fluorescence, X-ray diffraction analysis, and scanning electron microscopy. The alloys are hydrogenated at a temperature of 180°C and a pressure of 25–30 atm. It is established that all the hydrides of the nominal compositions Sm2Fe14.9Al2.1H3.6, Sm2Fe13.3Al3.8H2.1, Sm2Fe10.7Al6.3Н2, and Sm2Fe9.9Al7.1H1.8, like Sm2Fe17, are crystallized in the rhombohedral Th2Zn17 type of structure (space group R $$\overline{3}$$ m). The partial replacement of Fe in Sm2Fe17 by Al is accompanied by a monotonic increase in the lattice periods and a simultaneous decrease in the specific saturation magnetization of the studied alloys. A similar trend is also established for the hydride phases.