New ternary compounds in the Lu-{Ru,Rh}-{Si,Ge} systems

Investigations made by powder X-ray diffraction on new ternary LuRuSi,Lu2Ru3Si5,LuRu2Si2,LuRhSi,LuRh2Si2,LuRuGe,Lu4Ru7Ge6,LuRhGe,Lu4 Rh7Ge6 and Lu3Rh4Ge13 compounds are reported. The compounds LuRuSi(a=0.6823(1) nm,b=0.4188(1) nm,c=0.7151(1) nm),LuRhSi (a=0.6691(1) nm,b=0.4146(1) nm,c=0.7365(1) nm),LuRuGe(a=0.6871(1) nm, b=0.4259(1) nm,c=0.7305(1) nm) and LuRhGe(a=0.6736(1) nm,b=0.4216(1) nm,c=0.7493(1) nm) crystallize in the orthorhombic TiNiSi-type structure (space group Pnma). The Lu2Ru3Si5 compound (a=1.0611(1) nm,c=0.5537(1) nm) crystallizes in the tetragonal Sc2Fe3Si5-type structure (space group P4/mnc). The compounds LuRu2Si2 (a=0.4131(1) nm,c=0.9411(1) nm) and LuRh2Si2(a=0.4005(1) nm,c=0.9830(2) nm) crystallize in the tetragonal CeGa2Al2-type structure (space group I4/mmm). The compounds Lu4Ru7Ge6 (a=0.8239(1) nm) and Lu4Rh7Ge6(a=0.8244(1) nm) adopt the U4Re7Si6-type structure (space group Im3m). The Lu3Rh4Ge13 compound (a=0.8882(1) nm) belongs to the cubic Pr3Rh4Sn13-type structure (space group Pm3n). (orig.)