Isothermal section of the Ce–Au–Sb system at 870 K

Abstract

Phase equilibria in the Ce–Au–Sb system were derived from X-ray diffraction data and, optionally, from scanning electron microscope analysis of annealed at 870 K alloys. The structures of compounds were investigated using X-ray single crystal and powder diffraction methods. Five ternary compounds were found to exist within the investigated concentration region (0–50 at.% Ce). New U 3Cu 2Sb 3-type Ce 3Au 2Sb 3 compound ( a = 4.5966(4) Å, c = 24.005(2) Å, space group P6 3 /mmc, no. 194) was discovered and studied by X-ray single crystal diffraction. The existence and crystal structures of following compounds were confirmed at 870 K: the ZrCuSi 2-type CeAu 1− x Sb 2, UHg 2-type Ce(Au 1− x Sb x ) 2 and Y 3Au 3Sb 4-type Ce 3Au 3Sb 4. For the reported earlier UHg 2-type Ce(Au 1− x Sb x ) 2 and ZrCuSi 2-type CeAu 1− x Sb 2 compounds the homogeneity regions were established from annealed at 870 K alloys: 0.19 ≤ x ≤ 0.28 and 0 ≤ x ≤ 0.21 respectively. At 870 K, the structure of CeAuSb compound was found to be related to the CaIn 2-type from X-ray powder diffraction data. Moreover, the single crystal X-ray diffraction studies of the as-cast CeAu 1− x Sb 2 for x = 0.118(2) and x = 0.162(4) are given in present paper as well.