Crystal structure of the ternary compound La₂Ge_3.03Bi_0.81

Chem. Met. Alloys 13 (2020) 55-60

https://doi.org/10.30970/cma13.0405

Yaroslav TOKAYCHUK, Roman VYNNYK, Roman DANKEVYCH, Roman GLADYSHEVSKII

The new ternary intermetallic compound La₂Ge_3.03Bi_0.81 was synthesized, and its crystal structure was determined by X-ray powder diffraction (structure type Pr₂Ge_3.26Bi_0.62, Pearson symbol oS36, space group Cmcm, a = 4.2289(3), b = 31.915(2), c = 4.4379(3) Å, Z = 4). The structure is characterized by partial disorder of Bi and Ge atoms, which form a statistical mixture on one site, and by positional disorder of Ge atoms, modeled by split positions. The structure type Pr₂Ge_3.26Bi_0.62 is a member of the linear intergrowth structure series composed by AlB₂-type (triple slabs of trigonal prisms) and CaF₂-type (double slabs of “half octahedra”) fragments in the ratio 3:2.

Intergrowth of AlB₂- and CaF₂-type slabs in the structure of La₂Ge_3.03Bi_0.81.

Keywords

Lanthanum / Germanium / Bismuth / X-ray powder diffraction / Crystal structure