Transition metal nitrides, particularly those of 5d metals, are known for their outstanding properties, often relevant for industrial applications. Among these metal elements, tungsten is especially attractive given its low cost. In this high‐pressure investigation of the W–N system, two novel ultra‐incompressible tungsten nitride superconductors, namely W2N3 and W3N5, are successfully synthesized at 35 and 56 GPa, respectively, through a direct reaction between N2 and W in laser‐heated diamond anvil cells. Their crystal structure is determined using synchrotron single‐crystal X‐ray diffraction. While the W2N3 solid's sole constituting nitrogen species are N3‐ units, W3N5 features both discrete N3‐ as well as N24‐ pernitride anions. The bulk modulus of W2N3 and W3N5 is experimentally determined to be 380(3) and 406(7) GPa, and their ultra‐incompressible behavior is rationalized by their constituting WN7 polyhedra and their linkages. Importantly, both W2N3 and W3N5 are recoverable to ambient conditions and stable in air. Density functional theory calculations reveal W2N3 and W3N5 to have a Vickers hardness of 30 and 34 GPa, and superconducting transition temperatures at ambient pressure (50 GPa) of 11.6 K (9.8 K) and 9.4 K (7.2 K), respectively. Additionally, transport measurements performed at 50 GPa on W2N3 corroborate with the calculations.

中文翻译：

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高压合成超不可压缩硬质超导氮化钨


过渡金属氮化物，特别是 5d 金属氮化物，以其优异的性能而闻名，通常与工业应用相关。在这些金属元素中，钨因其低成本而特别有吸引力。在 W-N 系统的高压研究中，通过 N2 和 W 在激光加热中的直接反应，分别在 35 GPa 和 56 GPa 下成功合成了两种新型超不可压缩氮化钨超导体，即 W2N3 和 W3N5。金刚石砧细胞。它们的晶体结构是使用同步加速器单晶 X 射线衍射测定的。虽然 W2N3 固体的唯一组成氮物种是 N3- 单元，但 W3N5 具有离散的 N3- 和 N24- 过氮化物阴离子。 W2N3 和 W3N5 的体积模量经实验确定为 380(3) 和 406(7) GPa，它们的超不可压缩行为通过它们构成的 WN7 多面体及其连接合理化。重要的是，W2N3 和 W3N5 均可恢复至环境条件并在空气中稳定。密度泛函理论计算表明，W2N3 和 W3N5 的维氏硬度分别为 30 和 34 GPa，环境压力 (50 GPa) 下的超导转变温度分别为 11.6 K (9.8 K) 和 9.4 K (7.2 K)。此外，在 50 GPa 下对 W2N3 进行的输运测量也证实了计算结果。