Crystal structure of Dy₂Ga_1.8Ge_5.2

Chem. Met. Alloys 6 (2013) 220-224

https://doi.org/10.30970/cma6.0286

Yaroslav TOKAYCHUK, Taras DELENKO, Roman GLADYSHEVSKII

A new ternary intermetallic compound, Dy₂Ga_1.8Ge_5.2, was synthesized and its crystal structure determined from X-ray powder diffraction data: structure type Sm₂(Ga_0.26Ge_0.74)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(Ga_0.26Ge_0.74)₇ is closely related to the type Ce₂(Ga_0.1Ge_0.9)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 Dy₂Ga_1.8Ge_5.2 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 Dy₂Ga_1.8Ge_5.2.

Keywords

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