Crystal structure of the compound Tb_0.67Pt₂Al₅

Chem. Met. Alloys 2 (2009) 75-82

https://doi.org/10.30970/cma2.0096

Yuriy LUTSYSHYN, Yaroslav TOKAYCHUK, Roman GLADYSHEVSKII

The crystal structure of the ternary compound Tb_0.67PtAl₅ (structure type Sc_0.6Fe₂Si_4.9, hP20-4.67, P6₃/mmc, a = 4.2734(10), c = 16.391(3) Å) was refined from X-ray single-crystal diffraction data. It contains two kinds of slab stacked along [001]: slightly puckered layers of composition PtAl₂ and flat layers Tb_0.67Al with disordered distribution of Tb atoms and Al₃ triangles. Using group-subgroup relations, a hypothetical structure R₂T₆Al₁₅ with fully ordered distribution of R atoms and Al₃ triangles was derived (oS92, Cmcm, a = 12.820, b = 7.4017, c = 16.391 Å). Both structures together with some other structure types of ternary aluminides belong to a homologous series with the general formula R_0.67T_nM_2n+1.

	TbAl11Pt6Tb3		PtAl8Tb2
	Al1Al6Pt2Tb2	Al2Al6Pt4Tb	Al3Al5Pt3Tb2

Content of the unit cell and coordination polyhedra of the atoms in the structure of the compound Tb_0.67Pt₂Al₅.

Keywords

Aluminide / Terbium / Platinum / Single-crystal X-ray diffraction / Crystal-chemical analysis