New RRh_5Ge_3 compounds of the new SmRh_5Ge_3 structure type and their magnetic properties (R=Sm, Gd, Tb)

摘要

Powder X-ray diffraction results and macroscopic magnetic properties of new ternary RRh_5Ge_3 compounds (R=Sm, Gd, Tb) are reported. The compounds SmRh_5Ge_3 (a=2.2744(4) nm, c-0.3888(1) nm), GdRh_5Ge_3 (a=2.2711(5) nm, c=0.3872(1) nm) and TbRh_5Ge_3 (a-2.2628(7) nm, c=0.3851(1) nm) crystallize in the hexagonal SmRh_5Ge_3-type structure (space group P6_3/m; No. 176). The GdRh_5Ge_3 and TbRh_5Ge_3 compounds are Curie-Weiss paramagnets down to 5 K.