Intermetallic and metal-rich phases in the system Li–Ba–In–N

Three new intermetallic phases, BaLi2.1In1.9, BaLi1.12In0.98, and BaLi1.06In1.16 and two subnitrides Li35In45Ba39N9 and LiIn2Ba3N0.83 have been synthesized and their crystal structures have been determined. According to single crystal X-ray diffraction data BaLi2.1In1.9 and BaLi1.12In0.98 crystallize with hexagonal symmetry (BaLi2.1In1.9: P63/mmc, a=10.410(2), c=8.364(2) Å, Z=6, V=785.0(2) Å3) and BaLi1.12In0.98: P6/mmm, a=17.469(1), c=10.6409(7) Å, Z=30, V=2813.5(8) Å3), while BaLi1.06In1.16 has a rhombohedral structure (R-3c, a=18.894(3), c=85.289(17) Å, Z=276, V=26368(8) Å3). BaLi2.1In1.9 is isostructural with the known phase BaLi4. The phase BaLi1.12In0.98 is structurally related to Na8K23Cd12In48, while BaLi1.06In1.16 is isostructural with Li33.3Ba13.1Ca3. A sample containing structurally similar BaLi1.12In0.98 and BaLi1.02In1.16 was also investigated by transmission electron microscopy. Li35In45Ba39N9 and LiIn2Ba3N0.83 crystallize with tetragonal (I-42m, a=15.299(2), c=30.682(6) Å, Z=2, V=7182(2) Å3) and cubic (Fd-3m, a=14.913(2) Å, Z=8, V=3316.7(7) Å3) symmetry, respectively. While the first-mentioned subnitride belongs to the Li80Ba39N9 structure type, the second extends the structural family of Ba6In4.78N2.72. The structural features of the new compounds are discussed in comparison to the known phases and the results of total energy calculations.