Crystal structure of Dy2Ga1.8Ge5.2

 

Chem. Met. Alloys 6 (2013) 220-224

 

Yaroslav TOKAYCHUK, Taras DELENKO, Roman GLADYSHEVSKII

 

A new ternary intermetallic compound, Dy2Ga1.8Ge5.2, was synthesized and its crystal structure determined from X-ray powder diffraction data: structure type Sm2(Ga0.26Ge0.74)7, Pearson symbol oS80-8, space group Cmce, a = 8.3284(6), b = 8.0320(6), c = 20.9167(15) Å, Z = 8. The structure type Sm2(Ga0.26Ge0.74)7 is closely related to the type Ce2(Ga0.1Ge0.9)7. Both types are vacancy derivatives of the structure type SmNiGe3, which is a linear intergrowth of layers characteristic of the structure types BaAl4, AlB2, and α-Po. In the structure of Dy2Ga1.8Ge5.2 every second square antiprism in the BaAl4-type slabs is vacant and the Ga/Ge atoms centering the remaining antiprisms are subjected to displacement disorder modeled by a split site.

 

 

Intergrowth of AlB2-, α-Po-, and defect BaAl4-type slabs along [001] in the structure of Dy2Ga1.8Ge5.2.

 

Keywords

Dysprosium / Gallium / Germanium / X-ray powder diffraction / Crystal structure