Isothermal section of the Ce-Au-Sb system at 870Â K

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 U3Cu2Sb3-type Ce3Au2Sb3 compound (a = 4.5966(4) Å, c = 24.005(2) Å, space group P63/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 ZrCuSi2-type CeAu1−xSb2, UHg2-type Ce(Au1−xSbx)2 and Y3Au3Sb4-type Ce3Au3Sb4. For the reported earlier UHg2-type Ce(Au1−xSbx)2 and ZrCuSi2-type CeAu1−xSb2 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 CaIn2-type from X-ray powder diffraction data. Moreover, the single crystal X-ray diffraction studies of the as-cast CeAu1−xSb2 for x = 0.118(2) and x = 0.162(4) are given in present paper as well.