›› 2014, Vol. 23 ›› Issue (8): 86301-086301.doi: 10.1088/1674-1056/23/8/086301

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

Study on lattice vibrational properties and Raman spectra of Bi2Te3 based on density-functional perturbation theory

冯松科, 李双明, 傅恒志   

  1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University (NPU), Xi'an 710072, China
  • 收稿日期:2013-08-08 修回日期:2014-04-02 出版日期:2014-08-15 发布日期:2014-08-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 50971101 and 51074127) and the Research Fund of the State Key Laboratory of Solidification Processing (NPU) of China (Grant No. SKLSP201010).

Study on lattice vibrational properties and Raman spectra of Bi2Te3 based on density-functional perturbation theory

Feng Song-Ke (冯松科), Li Shuang-Ming (李双明), Fu Heng-Zhi (傅恒志)   

  1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University (NPU), Xi'an 710072, China
  • Received:2013-08-08 Revised:2014-04-02 Online:2014-08-15 Published:2014-08-15
  • Contact: Li Shuang-Ming E-mail:lsm@nwpu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 50971101 and 51074127) and the Research Fund of the State Key Laboratory of Solidification Processing (NPU) of China (Grant No. SKLSP201010).

摘要: We present a variational density-functional perturbation theory (DFPT) to investigate the lattice dynamics and vibrational properties of single crystal bismuth telluride material. The phonon dispersion curves and phonon density of states (DOS) of the material were obtained. The phonon dispersions are divided into two fields by a phonon gap. In the lower field, atomic vibrations of both Bi and Te contribute to the DOS. In the higher field, most contributions come from Te atoms. The calculated Born effective charges and dielectric constants reveal a great anisotropy in the crystal. The largest Born effective charge generates a significant dynamic charge transferring along the c axis. By DFPT calculation, the greatest LO-TO splitting takes place in the infrared phonon modes and reaches 1.7 THz in the Brillouin zone center. The Raman spectra and peaks corresponding to respective atomic vibration modes were found to be in good agreement with the experimental data.

关键词: density-functional perturbation theory, Bi2Te3 material, lattice vibrational properties, Raman spectra

Abstract: We present a variational density-functional perturbation theory (DFPT) to investigate the lattice dynamics and vibrational properties of single crystal bismuth telluride material. The phonon dispersion curves and phonon density of states (DOS) of the material were obtained. The phonon dispersions are divided into two fields by a phonon gap. In the lower field, atomic vibrations of both Bi and Te contribute to the DOS. In the higher field, most contributions come from Te atoms. The calculated Born effective charges and dielectric constants reveal a great anisotropy in the crystal. The largest Born effective charge generates a significant dynamic charge transferring along the c axis. By DFPT calculation, the greatest LO-TO splitting takes place in the infrared phonon modes and reaches 1.7 THz in the Brillouin zone center. The Raman spectra and peaks corresponding to respective atomic vibration modes were found to be in good agreement with the experimental data.

Key words: density-functional perturbation theory, Bi2Te3 material, lattice vibrational properties, Raman spectra

中图分类号:  (Phonons in crystal lattices)

  • 63.20.-e
63.20.D- (Phonon states and bands, normal modes, and phonon dispersion) 63.20.dk (First-principles theory) 78.30.-j (Infrared and Raman spectra)