Crystal structures of the
compounds GdAl0.09Ge2.07 and Gd2AlGe3
Chem.
Met. Alloys 7 (2014) 187-193
https://doi.org/10.30970/cma7.0310
Two gadolinium alumogermanides,
GdAl0.09(3)Ge2.07(4)
and Gd2AlGe3, were synthesized by arc melting and their
crystal structures were studied by X-ray powder diffraction. The compound GdAl0.09Ge2.07
crystallizes with an ErGe2.16-type structure:
Pearson symbol oS16, space group Cmcm, a = 4.1704(5),
b = 16.447(2), c = 3.9820(5) Å. It is the second known representative of the
structure type ErGe2.16 (a binary variant of
the type CeNiSi2) among rare-earth alumogermanides;
in both cases Al was found to partially substitute for Ge
on one of the fully occupied Ge sites. The compound
Gd2AlGe3 is isostructural to Y2AlGe3:
Pearson symbol oP24, space group Pnma, a
= 6.8031(2), b = 4.2282(1), c
= 17.8165(5) Å, and is the ninth representative
of this type. Common to the two structures is the presence of layers of Ge-centered Gd6 trigonal
prisms sharing the bases and two of the three lateral faces.
The structure of the gadolinium alumogermanide Gd2AlGe3; the Gd6 trigonal prisms centered by Ge atoms are emphasized.
Keywords
Gadolinium
/ Aluminum / Germanium / X-ray powder diffraction / Crystal structure