中国物理B ›› 2007, Vol. 16 ›› Issue (12): 3809-3814.doi: 10.1088/1009-1963/16/12/042

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Anisotropic properties of TaS2

乔彦彬1, 钟国华1, 曾 雉1, 秦晓英1, 李延龄2   

  1. (1)Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China; (2)Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China;Department of Physics, Xuzhou Normal University, Xuzhou 221116, China
  • 出版日期:2007-12-20 发布日期:2007-12-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos~90503005 and 50472097), the State Key Development Program for Basic Research of China (Grant No~2005CB623603), Knowledge Innovation Program of Chinese Academy of Scienc

Anisotropic properties of TaS2

Qiao Yan-Bin(乔彦彬)a), Li Yan-Ling(李延龄)a,b), Zhong Guo-Hua(钟国华)a), Zeng Zhi(曾雉)a)†, and Qin Xiao-Ying(秦晓英)a)   

  1. a Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China; b Department of Physics, Xuzhou Normal University, Xuzhou 221116, China
  • Online:2007-12-20 Published:2007-12-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos~90503005 and 50472097), the State Key Development Program for Basic Research of China (Grant No~2005CB623603), Knowledge Innovation Program of Chinese Academy of Scienc

摘要: The anisotropic properties of 1{T}- and 2{H}-TaS$_{2}$ are investigated by the density functional theory within the framework of full-potential linearized augmented plane wave method. The band structures of 1{T}- and 2{H}-TaS$_{2}$ exhibit anisotropic properties and the calculated electronic specific-heat coefficient $\gamma$ of 2{H}-TaS$_{2}$ accords well with the existing experimental value. The anisotropic frequency-dependent dielectric functions including the effect of the Drude term are analysed, where the $\varepsilon^{xx}(\omega)$ spectra corresponding to the electric field ${\bm E}$ perpendicular to the ${z}$ axis show excellent agreement with the measured results except for the $\varepsilon_{1}^{xx}(\omega)$ of 1{T}-TaS$_{2}$ below the energy level of 2.6 eV which is due to the lack of the enough CDW information for reference in our calculation. Furthermore, based on the values of optical effective mass ratio \emph{P} of 1{T} and 2{H} phases it is found that the anisotropy in 2{H}-TaS$_{2}$ is stronger than that in 1{T}-TaS$_{2}$.

关键词: anisotropic property, band structure, dielectric function

Abstract: The anisotropic properties of 1T- and 2H-TaS$_{2}$ are investigated by the density functional theory within the framework of full-potential linearized augmented plane wave method. The band structures of 1T- and 2H-TaS$_{2}$ exhibit anisotropic properties and the calculated electronic specific-heat coefficient $\gamma$ of 2H-TaS$_{2}$ accords well with the existing experimental value. The anisotropic frequency-dependent dielectric functions including the effect of the Drude term are analysed, where the $\varepsilon^{xx}(\omega)$ spectra corresponding to the electric field E perpendicular to the ${z}$ axis show excellent agreement with the measured results except for the $\varepsilon_{1}^{xx}(\omega)$ of 1T-TaS$_{2}$ below the energy level of 2.6 eV which is due to the lack of the enough CDW information for reference in our calculation. Furthermore, based on the values of optical effective mass ratio P of 1T and 2H phases it is found that the anisotropy in 2H-TaS$_{2}$ is stronger than that in 1T-TaS$_{2}$.

Key words: anisotropic property, band structure, dielectric function

中图分类号:  (Density functional theory, local density approximation, gradient and other corrections)

  • 71.15.Mb
65.40.Ba (Heat capacity) 71.15.Ap (Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.)) 71.18.+y (Fermi surface: calculations and measurements; effective mass, g factor) 71.20.Ps (Other inorganic compounds) 71.45.Gm (Exchange, correlation, dielectric and magnetic response functions, plasmons)