基于第一性原理的β-C_(3)N_(2)笼中原子嵌入引起的超硬磁性新材料设计  

First-principles predictions of new superhard magnetic clathrate materialβ-C_(3)N_(2) through atom embeddedness

作　　者：孙丽萍 付波涛 常景 Liping Sun;Botao Fu;Jing Chang(College of Physics and Electronic Engineering,Sichuan Normal University,Chengdu 610068,China;College of Physics and Electronic Engineering,Center for Computational Sciences,Sichuan Normal University,Chengdu 610068,China)

机构地区：[1]College of Physics and Electronic Engineering,Sichuan Normal University,Chengdu 610068,China [2]College of Physics and Electronic Engineering,Center for Computational Sciences,Sichuan Normal University,Chengdu 610068,China

出　　处：《Science China Materials》2024年第6期2032-2038,共7页中国科学（材料科学）（英文版）

基　　金：supported by the National Natural Science Foundation of China (12204330);Sichuan Normal University for financial support (341829001)。

摘　　要：基于第一性原理计算,我们通过将客体原子嵌入β-C_(3)N_(2)笼状结构的内在空腔中,预测了机械超硬和可控磁性的共存.以氢掺杂(H@β-C_(3)N_(2))和氟掺杂(F@β-C_(3)N_(2))为例,我们的研究表明两种掺杂构型是稳定的,并发现它们分别属于反铁磁半导体和铁磁半金属.这些有趣的磁相变源于它们在费米能级周围独特的能带结构,并可通过具有半填充占据的3D Hubbard模型和Stoner模型很好地解释.此外,H@β-C_(3)N_(2)和F@β-C_(3)N_(2)的高维氏硬度(49.0和48.2 GPa)表明它们具有笼状超硬材料特征.因此,氢和氟在β-C_(3)N_(2)笼中的掺杂分别产生了一种新型的超硬反铁磁半导体和超硬铁磁半金属,这些材料在极端条件下具有潜在的应用前景.我们的工作为设计具有优异机械性能和磁性的新型高性能多功能材料提供了一种有效的策略,这可能会为超硬材料未来在自旋电子学的应用提供理论依据.Using first-principles calculations,we predict the coexistence of mechanical superhardness and the con-trollable magnetism in the clathrate materialβ-C_(3)N_(2) through the implant of the external atom into the intrinsic cage structure.Taking hydrogen-doping(H@β-C_(3)N_(2))and fluorine-doping(F@β-C_(3)N_(2))as examples,our calculations indicate these two doped configurations are stable and discover that they belong to antiferromagnetic semiconductor and ferro-magnetic semi-metal,respectively.These intriguing magnetic phase transitions originate from their distinctive band struc-tures around the Fermi level and can be well understood by the three-dimensional Hubbard model with half-filling occupa-tion and the Stoner model.Moreover,the high Vickers hard-ness of 49.0 GPa for H@β-C_(3)N_(2) and 48.2 GPa for F@β-C_(3)N_(2) are obtained,suggesting they are clathrate superhard materi-als as their host.Therefore,the incorporations of H and F inβ-C_(3)N_(2) give rise to new types of superhard antiferromagnetic semiconductor and superhard ferromagnetic semimetal,re-spectively,which could have potential applications in harsh conditions.Our work provides an effective strategy to design a new class of highly desirable multifunctional materials with excellent mechanical properties and magnetic properties,which may arouse spintronic applications in superhard ma-terials in the future.

关 键 词：first-principles calculations clathrateβ-C_(3)N_(2) super-hard materials ferromagnetic semi-metal 

分 类 号：TB34[一般工业技术—材料科学与工程]