The first quaternary intermetallide with Sc3Ce2Si4-type
structure
Chem.
Met. Alloys 15 (2022)
8-11
https://doi.org/10.30970/cma15.0422
Svitlana PUKAS, Roksolana KOZAK
The crystal structure
of Tm2Ta3Ge2.67Si1.33 was solved
and refined from X-ray single-crystal diffraction data. It is isotypic to Sc3Ce2Si4:
Pearson symbol oP36, space group Pnma, a
= 6.848(2), b = 13.299(5), c = 7.032(3) Å, Z = 4; R = 0.0329, wR
= 0.0817 (for 608 independent reflections with F > 2σ(F) and 50
variables). The structure of the new quaternary compound is partly disordered
and characterized by statistic distribution of the smaller atoms, Ge and Si, which form pairs with the shortest distances 2.677(3) and 2.561(4) Å. The structure
of Tm2Ta3Ge2.67Si1.33 can be described as a stacking of slabs along the
crystallographic direction [010]. The slabs are formed by Ta-centered rhombic
dodecahedra and are connected via
common faces.
Projection of the structure of Tm2Ta3Ge2.67Si1.33
along [100].
Keywords
Germanium / Silicon /
Tantalum / Thulium / X-ray single crystal diffraction / Crystal structure