Crystal Structure of the New Ternary Uranium Germanide UNi5Ge3 and Magnetic Properties of UNi5X3 (X: Ge, Si).

Abstract The ternary compound UNi 5 Ge 3 was prepared for the first time and its structure was determined from X-ray single-crystal data. UNi 5 Ge 3 has a YNi 5 Si 3 type of structure ( Pnma space group) with the orthorhombic lattice constants a =19.1399(4) A, b =3.9158(1) A and c =6.7461(1) A. From susceptibility measurements, an antiferromagnetic ordering below T N =41 K was observed for UNi 5 Ge 3 , while the isotypic silicide UNi 5 Si 3 is paramagnetic down to 2 K.