Crystal structure
of the ternary compound La2Ge3.03Bi0.81
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 La2Ge3.03Bi0.81 was synthesized, and its crystal structure was
determined by X-ray powder diffraction (structure type Pr2Ge3.26Bi0.62, 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 Pr2Ge3.26Bi0.62
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 La2Ge3.03Bi0.81.
Keywords
Lanthanum
/ Germanium / Bismuth / X-ray powder diffraction / Crystal structure