ИСТИНА

New intermetallic compounds of variable composition RE26(RuxIn1-x)17 (RE - Pr, Nd, Sm, Gd-Tm, Lu) are formed in region with high content of RE of the ternary systems RE-Ru-In. New indides belong to the Sm26(CoxGa1-x)17 structure type. Previously, iso-structural compounds were obtained for gallides of rare-earth elements with transition metals T - Co, Ni, Ru. Intermetallic compounds under consideration are the first indides of Sm26(CoxGa1-x)17 structure type. For the synthesis of rare earth-rich indides with ruthenium, elementary components were arc-melted in an argon atmosphere, followed by annealing at 600°C for 720 hours and subsequent quenching in cold water. The structures of the compounds were refined from powder X-ray diffraction data by the Rietveld method using the structural model of Sm26(CoxGa1-x)17. RE26(RuxIn1-x)17 (RE - Pr, Nd, Sm, Gd-Tm, Lu) crystallize in tetragonal system with the space group P4/mbm, Z = 2. Unit cell parameters in the series of indides range from a = 12.201(4) Å, c = 16.198(10) Å (Pr) to a = 11.5448(15), c = 15.786(4) Å (Lu). The cell volumes decrease from the praseodymium to the lutetium as expected from the lanthanide contraction.