The quasi-binary system SmGa2

The quasi-binary system SmGa₂–SmAl₂ at 600ºC

Chem. Met. Alloys 4 (2011) 251-256

https://doi.org/10.30970/cma4.0202

Taras SLIVINSKYY, Yaroslav TOKAYCHUK, Karin CENZUAL, Roman GLADYSHEVSKII

Alloys of the quasi-binary system SmGa₂–SmAl₂ annealed at 600ºC were investigated by X-ray powder diffraction. Formation of a ternary compound, SmGa_1.00-0.75Al_1.00-1.25 (structure type AlB₂, Pearson symbol hP3, space group P6/mmm, a = 4.4463(2)-4.4784(2), c = 3.7646(2)-3.7230(2) Å) and substitutional solid solutions of the binary compounds, SmGa_2‑1.32Al_0‑0.68 (structure type AlB₂, hP3, P6/mmm, a = 4.235-4.2947(2), c = 4.183-4.1419(3) Å) and SmGa_0‑0.21Al_2‑1.79 (structure type MgCu₂, cF24, Fd-3m, a = 7.942-7.9283(2) Å), was established. Replacement of Ga atoms by Al atoms along the 33.3 at.% Sm isoconcentrate leads to an increase of the space-filling coefficient from 68.4 (SmGa₂) to 78.8 % (SmAl₂).

Space-filling coefficient for the phases in the SmGa₂–SmAl₂ system as a function of the Al content.

Keywords

Samarium / Aluminum / Gallium / X-ray powder diffraction / Crystal structure / Solid solution