中国物理B ›› 2015, Vol. 24 ›› Issue (2): 26501-026501.doi: 10.1088/1674-1056/24/2/026501

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

Effects of in-plane stiffness and charge transfer on thermal expansion of monolayer transition metal dichalcogenide

王占雨a b, 周艳丽c, 王雪青b, 王飞a b, 孙强a b, 郭正晓a b d, 贾瑜a b   

  1. a International Joint Research Laboratory for Quantum Functional Materials of Henan, Zhengzhou University, Zhengzhou 450001, China;
    b School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China;
    c Department of Mechanical and Electrical Engineering, Henan Industry and Trade Vocational College, Zhengzhou 451191, China;
    d Department of Chemistry, University College London, London WC1H 0AJ, U.K.
  • 收稿日期:2014-07-11 修回日期:2014-10-13 出版日期:2015-02-05 发布日期:2015-02-05
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11274280 and 11104254) and the National Basic Research Program of China (Grant No. 2012CB921300).

Effects of in-plane stiffness and charge transfer on thermal expansion of monolayer transition metal dichalcogenide

Wang Zhan-Yu (王占雨)a b, Zhou Yan-Li (周艳丽)c, Wang Xue-Qing (王雪青)b, Wang Fei (王飞)a b, Sun Qiang (孙强)a b, Guo Zheng-Xiao (郭正晓)a b d, Jia Yu (贾瑜)a b   

  1. a International Joint Research Laboratory for Quantum Functional Materials of Henan, Zhengzhou University, Zhengzhou 450001, China;
    b School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China;
    c Department of Mechanical and Electrical Engineering, Henan Industry and Trade Vocational College, Zhengzhou 451191, China;
    d Department of Chemistry, University College London, London WC1H 0AJ, U.K.
  • Received:2014-07-11 Revised:2014-10-13 Online:2015-02-05 Published:2015-02-05
  • Contact: Jia Yu E-mail:jiayu@zzu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11274280 and 11104254) and the National Basic Research Program of China (Grant No. 2012CB921300).

摘要: The temperature dependence of lattice constants is studied by using first-principles calculations to determine the effects of in-plane stiffness and charge transfer on the thermal expansions of monolayer semiconducting transition metal dichalcogenides. Unlike the corresponding bulk material, our simulations show that monolayer MX2 (M=Mo and W; X=S, Se, and Te) exhibits a negative thermal expansion at low temperatures, induced by the bending modes. The transition from contraction to expansion at higher temperatures is observed. Interestingly, the thermal expansion can be tailored regularly by alteration of the M or X atom. Detailed analysis shows that the positive thermal expansion coefficient is determined mainly by the in-plane stiffness, which can be expressed by a simple relationship. Essentially the regularity of this change can be attributed to the difference in charge transfer between the different elements. These findings should be applicable to other two-dimensional systems.

关键词: transition metal dichalcogenide, thermal expansion, phonon

Abstract: The temperature dependence of lattice constants is studied by using first-principles calculations to determine the effects of in-plane stiffness and charge transfer on the thermal expansions of monolayer semiconducting transition metal dichalcogenides. Unlike the corresponding bulk material, our simulations show that monolayer MX2 (M=Mo and W; X=S, Se, and Te) exhibits a negative thermal expansion at low temperatures, induced by the bending modes. The transition from contraction to expansion at higher temperatures is observed. Interestingly, the thermal expansion can be tailored regularly by alteration of the M or X atom. Detailed analysis shows that the positive thermal expansion coefficient is determined mainly by the in-plane stiffness, which can be expressed by a simple relationship. Essentially the regularity of this change can be attributed to the difference in charge transfer between the different elements. These findings should be applicable to other two-dimensional systems.

Key words: transition metal dichalcogenide, thermal expansion, phonon

中图分类号:  (Thermal properties of small particles, nanocrystals, nanotubes, and other related systems)

  • 65.80.-g
63.22.Np (Layered systems)