Layered metal carbo–selenide Nb_(2)CSe_(2) with van der Waals interlayer coupling  

作　　者：Junchao Wang Renfei Cheng Tao Hu Xinyue Tang Yan Liang Min Tian Ting Xiong Qiuhong Lu Qi Zhu Zhiqing Yang Xiaohui Wang Yanchun Zhou 

机构地区：[1]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China [3]Institute of Materials Science and Devices,School of Materials Science and Engineering,Suzhou University of Science and Technology,Suzhou 215009,China [4]School of Materials Science and Engineering,Shenyang Ligong University,Shenyang 110159,China [5]Ji Hua Laboratory,Foshan 528000,China [6]Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education),School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China [7]School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China

出　　处：《Journal of Advanced Ceramics》2025年第1期101-110,共10页先进陶瓷(英文)

基　　金：supported by the Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Basic and Applied Basic Research Program of Guangdong Province(No.2021B0301030003);Ji Hua Laboratory(No.X210141TL210)。

摘　　要：The stacking structure of Nb_(2)CSe_(2),a newly synthesized layered metal carbo-selenide,was elucidated by scanning transmission electron microscopy.Nb,CSe2 features Se-Nb-C-Nb-Se quintuple atomic layers.These layers are stacked in Bernal mode.In this mode,Nb,CSe2 crystallizes in a trigonal symmetry(space group P3m1,No.164),with lattice parameters of a=3.33 A and c=18.20 A.Electronic structure calculations indicate that the metal carbo-selenide has Fermi energy crossing the bands where it touches to give a zero gap,indicating that it is an electronic conductor.As evidenced experimentally,the electrical conductivity is as high as 6.6×10^(5) S·m^(-1),outperforming the counterparts in the MXene family.Owing to the layered structure,the bonding in Nb_(2)CSe_(2) with an ionic formula of(Nb^(1.48+)),(C^(1.74-))(Se^(0.61-))_(2) is highly anisotropic,with metallic-covalent-ionic bonding in intralayers and weak bonding between interlayers.The layered nature is further evidenced by elastic properties,interlayer energy,and friction coefficient determination.These characteristics indicate that Nb_(2)CSe_(2) is an analog of molybdenum disulfide(MoS_(2)),which is a typical binary van der Waals(vdW)solid.Moreover,vibrational properties are reported,which may offer an optical identification standardfor new ternary vdW solids in spectroscopic studies,including Raman scatteringand infrared absorption.

关 键 词：MXene Nb_(2)CSe_(2) crystal structure electronic structure elastic properties interlayer coupling Raman spectroscopy friction coefficient 

分 类 号：TQ174.7[化学工程—陶瓷工业]