Rare-earth cobalt aluminides
with Y2Co3Ga9-type structure
Chem.
Met. Alloys 4 (2011) 243-250
https://doi.org/10.30970/cma4.0201
Yuriy LUTSYSHYN, Yaroslav TOKAYCHUK, Roman
GLADYSHEVSKII
Two new rare-earth cobalt aluminides, Gd2Co3Al9
and Tb2Co3Al9, were synthesized. Their crystal
structures and the structure of Sm2Co3Al9 were
refined from X-ray powder diffraction data: Y2Co3Ga9
structure type, oS56, Cmcm, a = 12.8263(7), b = 7.5192(4),
c = 9.4054(6) Å for the Sm-containing
compound, a = 12.7883(8),
b = 7.4955(5), c = 9.3711(6)
Å for the Gd-containing compound, and a
= 12.7606(9), b = 7.4783(5),
c = 9.3332(6) Å for the Tb-containing
compound. The structures are built from monoatomic R4Al6 layers (triangle mesh of R atoms and Al3 triangles in
ratio 2:1) and puckered Co6Al12 layers (triangle mesh of
Co and Al atoms in the ratio 1:2) alternating along [001].
Perspective view of the structure of R2Co3Al9 (Y2Co3Ga9
type)
Keywords
Aluminide / Rare-earth metal / Cobalt / X-ray
powder diffraction / Crystal structure