Investigation of the phase diagrams of the systems R-Ni-Pb (RÂ =Â Y, La, Ce, Dy) and crystal structures of the compounds R4Ni3Pb4 (RÂ =Â La, Ce, Pr) and R5NiPb3 (RÂ =Â Y, La, Ce, Pr, Tb, Dy, Ho, Er, Tm, Lu)

The isothermal sections of the systems Y-Ni-Pb (at 870 K), La-Ni-Pb (at 670 K), Ce-Ni-Pb (at 670 K) and Dy-Ni-Pb (at 870 K) were constructed using X-ray phase analysis. Five ternary compounds were found in the Y-Ni-Pb system: YNiPb (TiNiSi structure type, space group Pnma, a = 0.71590(4) nm, b = 0.45176(2) nm, c = 0.77610(4) nm), Y2Ni2Pb (Mn2AlB2 structure type, space group Cmmm, a = 0.4019(1) nm, b = 1.4008(3) nm, c = 0.3679(1) nm), Y5NiPb3 (Hf5CuSn3 structure type, space group P63/mcm, a = 0.8991(1) nm, c = 0.66393(4) nm), Y12Ni6Pb (Sm12Ni6In structure type, space group Im3, a = 0.97149(2) nm) and Y6Ni2.5Pb0.5 (Ho6Co2Ga structure type, space group Immm, a = 0.9462(1) nm, b = 0.9605(1) nm, c = 0.9891(1) nm). The existence of the compounds La4Ni3Pb4 (La4Ni3Pb4 structure type, space group R3, a = 1.00367(7) nm, c = 0.95558(8) nm), La5NiPb3 (Hf5CuSn3 structure type, space group P63/mcm, a = 0.94867(4) nm, c = 0.69839(4) nm), La12Ni6Pb (Sm12Ni6In structure type, space group Im3, a = 1.0233(2) nm) in the La-Ni-Pb system and the compounds Ce4Ni3Pb4 (La4Ni3Pb4 structure type, space group R3, a = 0.9947(1) nm, c = 0.94604(9) nm), Ce5NiPb3 (Hf5CuSn3 structure type, space group P63/mcm, a = 0.93839(4) nm, c = 0.67922(4) nm) in the Ce-Ni-Pb system was determined. The existence of five ternary compounds DyNiPb (TiNiSi structure type, space group Pnma, a = 0.71485(5) nm, b = 0.45219(3) nm, c = 0.77481(6) nm), Dy2Ni2Pb (Mn2AlB2 structure type, space group Cmmm, a = 0.4026(1) nm, b = 1.3994(4) nm, c = 0.3651(1) nm), Dy5NiPb3 (Hf5CuSn3 structure type, space group P63/mcm, a = 0.8956(1) nm, c = 0.65733(7) nm), Dy12Ni6Pb (Sm12Ni6In structure type, space group Im3, a = 0.9662(1) nm) and Dy6Ni2.39Pb0.55 (Ho6Co2Ga structure type, space group Immm, a = 0.93748(3) nm, b = 0.95427(3) nm, c = 0.98823(3) nm) in the Dy-Ni-Pb system was established. Additionally the existence of the compounds Pr4Ni3Pb4 (La4Ni3Pb4 structure type, space group R3, a = 0.9889(1) nm, c = 0.9417(1) nm), Pr5NiPb3 (Hf5CuSn3 structure type, space group P63/mcm, a = 0.9337(1) nm, c = 0.67927(6) nm), Tb5NiPb3 (Hf5CuSn3 structure type, space group P63/mcm, a = 0.90448(7) nm, c = 0.66101(3) nm), Ho5NiPb3 (Hf5CuSn3 structure type, space group P63/mcm, a = 0.89315(6) nm, c = 0.65649(2) nm), Er5NiPb3 (Hf5CuSn3 structure type, space group P63/mcm, a = 0.89065(7) nm, c = 0.65631(3) nm), Tm5NiPb3 (Hf5CuSn3 structure type, space group P63/mcm, a = 0.88655(8) nm, c = 0.65302(3) nm), Lu5NiPb3 (Hf5CuSn3 structure type, space group P63/mcm, a = 0.8775(1) nm, c = 0.65116(6) nm).