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First‐principles calculation of vibrational properties of B 12 As 2 crystal
Author(s) -
Fan Zhaochuan,
Wang Bin,
Xu Xiaoxuan,
Cao Xuewei,
Wang Yufang
Publication year - 2011
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201046406
Subject(s) - raman spectroscopy , brillouin zone , phonon , normal mode , crystal (programming language) , atmospheric temperature range , molecular vibration , materials science , molecular physics , condensed matter physics , atomic physics , physics , optics , vibration , thermodynamics , quantum mechanics , computer science , programming language
We use density functional perturbation theory (DFPT) to simulate the 26 vibrational modes of B 12 As 2 crystal at the Γ point. All the 12 Raman‐active modes are in good agreement with experimental Raman spectra of B 12 As 2 . We explain several controversial modes of the past, such as the predicted Raman‐active mode with a low frequency and the Raman‐active mode at 503 cm −1 . We also plot the dispersion curves of B 12 As 2 from Brillouin zone center to Z (0.5, 0.5, 0.5) and to A (0.5, 0.0, 0.0). We determine the acoustic branch speeds to be in the range 9850–10 980 m/s for LA and 6940–7220 m/s for TA modes. Finally, we give the predicted physical properties, including the phonon entropy, the phonon heat capacity, elastic constants, and bulk modulus.