Isothermal section of the Ce-Au-Sb system at 870 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 U(3)Cu(2)Sb(3)-type Ce(3)Au(2)Sb(3) compound (a=4.5966(4)angstrom, c=24.005(2)angstrom, 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(3)Au(3)Sb(4)-type Ce(3)Au(3)Sb(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. (C) 2009 Elsevier B.V. All rights reserved.