A new subnitride in the series NanBa14CaN6 with n = 8

First-Principles Study of Three-Dimensional Electrides Containing One-Dimensional [Ba3N]3+ Chains

Electrides, a unique type of compound where electrons act as anions, have a high electron mobility and a low work function, which makes them promising for applications in electronic devices and high-performance catalysts. The discovery of novel electrides and the expansion of the electride family have great significance for their promising applications. Herein, we reported four three-dimensional (3D) electrides by coupling crystal structure database searches and first-principles electronic structure analysis. Subnitrides (Ba₃N, LiBa₃N, NaBa₃N, and Na₅Ba₃N) containing one-dimensional (1D) [Ba₃N]³⁺ chains are identified as 3D electrides for the first time. The anionic electrons are confined in the 3D interstitial space of Ba₃N, LiBa₃N, NaBa₃N, and Na₅Ba₃N. Interestingly, with the increase of Na content, the excess electrons of Na₅Ba₃N play two roles of metallic bonding and anionic electrons. Therefore, the subnitrides containing 1D [Ba₃N]³⁺ chains can be regarded as a new family of 3D electrides, where anionic electrons reside in the 3D interstitial spaces and provide a conduction path. These materials not only are experimentally synthesizable 3D electrides but also are promising to be exfoliated into advanced 1D nanowire materials. Furthermore, our work suggests a discovery strategy of novel electrides based on one parent framework like [Ba₃N]³⁺ chains, which would accelerate the mining of electrides from the crystal structure database.

Plasma-Assisted Synthesis and Properties of Na3N

Dark-blue sodium nitride, Na(3)N, was prepared by the reaction of metallic sodium or liquid Na-K alloy with plasma-activated nitrogen at low pressure. The compound crystallizes in the cubic anti-ReO(3)-type structure (space group Pm3m with a = 4.73301(6) Angstrom and Z = 1) according to powder and single-crystal X-ray diffraction data. Na(3)N decomposes above 104 degrees C into the elements, with DeltaH(f) estimated at +64(2) kJ/mol.