High-pressure synthesis of fully sp2-hybridized polymeric nitrogen layer in potassium supernitride

Minghong Sui; Shuang Liu; Peng Wang; Nianlong Zou; Qing Dong; Miao Zhou; Shifeng Niu; Lei Yue; Zitong Zhao; Linlin Guo; Bo Liu; Ran Liu; Yong Xu; Zhen Yao; Bingbing Liu

doi:10.1016/j.scib.2023.06.029

High-pressure synthesis of fully sp²-hybridized polymeric nitrogen layer in potassium supernitride

Sci Bull (Beijing). 2023 Jul 30;68(14):1505-1513. doi: 10.1016/j.scib.2023.06.029. Epub 2023 Jun 30.

Authors

Minghong Sui¹, Shuang Liu¹, Peng Wang², Nianlong Zou³, Qing Dong⁴, Miao Zhou¹, Shifeng Niu¹, Lei Yue¹, Zitong Zhao¹, Linlin Guo¹, Bo Liu¹, Ran Liu¹, Yong Xu³, Zhen Yao⁵, Bingbing Liu⁶

Affiliations

¹ State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China.
² State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China. Electronic address: wangpengtrrs@jlu.edu.cn.
³ State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China.
⁴ State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China; Institute for High Pressure, Department of Physics, Hanyang University, Seoul 04763, Republic of Korea.
⁵ State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China. Electronic address: yaozhen@jlu.edu.cn.
⁶ State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China. Electronic address: liubb@jlu.edu.cn.

PMID: 37438156
DOI: 10.1016/j.scib.2023.06.029

Abstract

Searching for fully sp²-hybridized layered structures is of fundamental importance because of their fascinating physical properties and potential to host topologically non-trivial electronic states. However, the synthesis of fully sp²-hybridized layered polymeric nitrogen structures remains a challenging work because of their low stability. Here, we report the synthesis of a fully sp²-hybridized layered polymeric nitrogen structure featuring fused 18-membered rings in potassium supernitride (K₂N₁₆) under high-pressure and high-temperature conditions. Bader charge analysis reveals that the potassium atomic layer stabilizes the unique sp²-hybridized polymeric nitrogen layers through the charge transfer effect in K₂N₁₆. The calculation of electronic structure indicates that K₂N₁₆ is a topological semimetal with multiple Dirac points and hosts higher-order Dirac fermions with cubic dispersion, which are contributed by the sp²-hybridized polymeric nitrogen layers arranged in P6/mcc symmetry. The high-pressure synthesis of the fully sp²-hybridized polymeric nitrogen layered structure provides promising prospects for exploring novel topological materials with effective stabilization routes.

Keywords: Graphene-like; High pressure; Layered polymeric nitrogen structures; Topological electronic structure.