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Structural, Electronic and Vibrational Properties of Al 4 C 3
Author(s) -
Kioseoglou Joseph,
LeTran HoangLong,
Giaremis Stefanos,
Gelard Isabelle,
Ouisse Thierry,
Chaussende Didier,
Sarigiannidou Eirini
Publication year - 2019
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.201900037
Subject(s) - band gap , raman spectroscopy , phonon , ab initio , materials science , direct and indirect band gaps , valence band , diffraction , effective mass (spring–mass system) , valence (chemistry) , ab initio quantum chemistry methods , aluminium , absorption (acoustics) , molecular physics , atomic physics , condensed matter physics , chemistry , optoelectronics , optics , physics , molecule , organic chemistry , quantum mechanics , metallurgy , composite material
Al 4 C 3 single crystals are synthesized by the reaction between SiC and aluminum and are structurally verified and analyzed by Raman and X‐ray diffraction spectra. The optical absorption measurements of the Al 4 C 3 crystals indicated that the bandgap is about 2.3 eV, which surprisingly is much higher than the bandgap value from the literature. In order to elucidate the discrepancy between the new experimental results and the literature, an advanced ab initio based investigation on the structural, electronic and vibrational properties of the Al 4 C 3 is performed. Remarkably, the scGW approach arrived at an indirect band gap Γ → L equal to 2.12 eV while the HSE06 calculated band gap was found even closer to the experimental value equal to 2.27 eV. In addition, the hole effective mass is found to be considerably high due to the flat nature of the valence band at the Γ, indicating low hole mobility. Moreover, phonon calculations indicated that the vibrations of the Al atoms contribute mostly on low frequency acoustic branches, while vibrations from C atoms have a stronger contribution to optical phonons.