YbFeGe, a New Structure Type of Equiatomic Ternary Germanides.

Abstract The crystal structure of the new ternary germanide YbFeGe, space group C2/m (N12), a =10.607(6) A, b =3.904(2) A, c =6.715(3) A, β =127.58(1)°, Z =4, V =220.35 A, ρ =9.088 g cm −3 , μ =61.67 mm −1 was refined to R =0.0313, wR2 =0.0705 from single crystal X-ray diffraction data. This is the first representative of a new structure type (str. type) of intermetallic compounds. The formation and crystal structure for this compound were confirmed from X-ray powder diffraction: a =10.5755(5) A, b =3.9034(3) A, c =6.7117(4) A, β =127.68°. An isotypic YbMnGe compound was observed: YbFeGe str. type, C2/m space group (sp. gr.), a =10.5966(4) A, b =3.9014(2) A, c =6.7782(3) A, β =127.42°. The crystal structures for the YbCoGe compound (TiNiSi str. type, Pnma sp. gr., a =6.7168(4) A, b =4.0392(2) A, c =7.2684(4) A) and YbMn 2 Ge 2 compound (CeGa 2 Al 2 str. type, I4/mmm sp. gr., a =4.0334(5) A, c =10.0334(7) A) are reported for the first time.