Single crystals of BaAl2Si2 were grown from an Al molten flux and characterized using single-crystal X-ray diffraction at 10 and 90 K and neutron diffraction at room temperature. BaAl2Si2 crystallizes with the α-BaCu2S2 structure type (Prima), is isostructural with α-BaAl2Ge2, and is an open 3D framework compound, where Al and Si form a covalent cagelike network with Ba2+ cations residing in the cages. BaAl2Si 2 has a unit cell of a = 10.070(3) Å, b = 4.234(1) Å, and c = 10.866(3) Å, as determined by room-temperature single-crystal neutron diffraction (R1 - 0.0533, wR2 = 0.1034). The structure as determined by single-crystal neutron and X-ray diffraction (10 and 90 K) indicates that BaAl2Si2 (Prima) is strictly isostructural to other (α)-BaCu2S2-type structures, requiring site specificity for Al and Si. Unlike BaAl2Ge2, no evidence for an a to B (BaZn2P2-type, I4A/mmm) phase transition was observed. This compound shows metallic electronic resistivity and Pauli paramagnetic behavior.
ASJC Scopus subject areas
- Inorganic Chemistry