Work

Study on lattice vibrational properties and Raman spectra of Bi 2 Te 3 based on density-functional perturbation theory

Year: 2014

Type: article

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.

Source: Chinese Physics B

DOI: 10.1088/1674-1056/23/8/086301

Authors: Song-Ke Feng, Shuang-Ming Li, Heng-Zhi Fu

Institutions: Northwestern Polytechnical University, State Key Laboratory of Solidification Processing

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: bronze

Funders: National Natural Science Foundation of China, State Key Laboratory of Solidification Processing

Award: G409641022