中国物理B ›› 2020, Vol. 29 ›› Issue (5): 56201-056201.doi: 10.1088/1674-1056/ab8214

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Electronic structure and phase transition engineering in NbS2: Crucial role of van der Waals interactions

Wei Wang(王威), Wen Lei(雷文), Xiaojun Zheng(郑晓军), Huan Li(黎欢), Xin Tang(唐鑫), Xing Ming(明星)   

  1. 1 College of Science, Guilin University of Technology, Guilin 541004, China;
    2 Key Laboratory of New Processing Technology for Nonferrous Metal&Materials, Ministry of Education, School of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, China
  • 收稿日期:2020-02-06 修回日期:2020-03-13 出版日期:2020-05-05 发布日期:2020-05-05
  • 通讯作者: Xing Ming E-mail:mingxing@glut.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11864008) and Guangxi Natural Science Foundation, China (Grant Nos. 2018GXNSFAA138185 and 2018AD19200). High performance computational resources provided by LvLiang Cloud Computing Center of China and National Supercomputer Center on TianHe-2 are gratefully acknowledged.

Electronic structure and phase transition engineering in NbS2: Crucial role of van der Waals interactions

Wei Wang(王威)1, Wen Lei(雷文)1, Xiaojun Zheng(郑晓军)1, Huan Li(黎欢)1, Xin Tang(唐鑫)2, Xing Ming(明星)1   

  1. 1 College of Science, Guilin University of Technology, Guilin 541004, China;
    2 Key Laboratory of New Processing Technology for Nonferrous Metal&Materials, Ministry of Education, School of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, China
  • Received:2020-02-06 Revised:2020-03-13 Online:2020-05-05 Published:2020-05-05
  • Contact: Xing Ming E-mail:mingxing@glut.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11864008) and Guangxi Natural Science Foundation, China (Grant Nos. 2018GXNSFAA138185 and 2018AD19200). High performance computational resources provided by LvLiang Cloud Computing Center of China and National Supercomputer Center on TianHe-2 are gratefully acknowledged.

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摘要： Based on first-principles simulations, we revisit the crystal structures, electronic structures, and structural stability of the layered transition metal dichalcogenides (TMDCs) NbS2, and shed more light on the crucial roles of the van der Waals (vdW) interactions. Theoretically calculated results imply that the vdW corrections are important to reproduce the layered crystal structure, which is significant to correctly describe the electronic structure of NbS2. More interestingly, under hydrostatic pressure or tensile strain in ab plane, an isostructural phase transition from two-dimensional layered structure to three-dimensional bulk in the I4/mmm phase has been uncovered. The abnormal structural transition is closely related to the electronic structure instability and interlayer bonding effects. The interlayer Nb-S distances collapse and the interlayer vdW interactions disappear, concomitant with new covalent bond emerging and increasing coordination number. Present work highlights the significance of the vdW interactions, and provides new insights on the unconventional structural transitions in NbS2, which will attract wide audience working in the hectic field of TMDCs.

关键词: NbS2, high pressure, phase transition, van der Waals (vdW) interactions

Abstract: Based on first-principles simulations, we revisit the crystal structures, electronic structures, and structural stability of the layered transition metal dichalcogenides (TMDCs) NbS2, and shed more light on the crucial roles of the van der Waals (vdW) interactions. Theoretically calculated results imply that the vdW corrections are important to reproduce the layered crystal structure, which is significant to correctly describe the electronic structure of NbS2. More interestingly, under hydrostatic pressure or tensile strain in ab plane, an isostructural phase transition from two-dimensional layered structure to three-dimensional bulk in the I4/mmm phase has been uncovered. The abnormal structural transition is closely related to the electronic structure instability and interlayer bonding effects. The interlayer Nb-S distances collapse and the interlayer vdW interactions disappear, concomitant with new covalent bond emerging and increasing coordination number. Present work highlights the significance of the vdW interactions, and provides new insights on the unconventional structural transitions in NbS2, which will attract wide audience working in the hectic field of TMDCs.

Key words: NbS2, high pressure, phase transition, van der Waals (vdW) interactions

中图分类号:  (High-pressure effects in solids and liquids)

  • 62.50.-p
71.20.-b (Electron density of states and band structure of crystalline solids) 71.15.Mb (Density functional theory, local density approximation, gradient and other corrections)