Wang, YiBobev, Svilen2023-05-162023-05-162023-02-08Wang, Yi, and Svilen Bobev. 2023. "Synthesis and Crystal Structure of the Zintl Phases NaSrSb, NaBaSb and NaEuSb" Materials 16, no. 4: 1428. https://doi.org/10.3390/ma160414281996-1944https://udspace.udel.edu/handle/19716/32752This article was originally published in Materials. The version of record is available at: https://doi.org/10.3390/ma16041428This work details the synthesis and the crystal structures of the ternary compounds NaSrSb, NaBaSb and NaEuSb. They are isostructural and adopt the hexagonal ZrNiAl-type structure (space group P6¯2m; Pearson code hP9). The structure determination in all three cases was performed using single-crystal X-ray diffraction methods. The structure features isolated Sb3– anions arranged in layers stacked along the crystallographic c-axis. In the interstices, alkali and alkaline-earth metal cations are found in tetrahedral and square pyramidal coordination environments, respectively. The formal partitioning of the valence electrons adheres to the valence rules, i.e., Na+Sr2+Sb3–, Na+Ba2+Sb3– and Na+Eu2+Sb3– can be considered as Zintl phases with intrinsic semiconductor behavior. Electronic band structure calculations conducted for NaBaSb are consistent with this notion and show a direct gap of approx. 0.9 eV. Additionally, the calculations hint at possible inverted Dirac cones, a feature that is reminiscent of topological quantum materials.en-USantimonidescrystal structurethermoelectricstopological insulatorZintl phasesArticle