Anharmonic lattice dynamics of bcc sodium under high pressures

文献情報

出版日 2018-05-12

DOI 10.1039/C8CP02086H

インパクトファクター 3.676

著者

Shasha Li, Chen Wang, Yue Chen

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要旨

Phonon–phonon coupling in body centered cubic (bcc) sodium is studied from first-principles to investigate its anharmonic lattice dynamics under high pressures. The renormalization of the phonon frequencies of the transverse acoustic (TA) modes along the Γ–N direction is found to be distinctly different compared with other phonon modes. We find that these TA modes firstly stiffen with increasing external pressure below 30 GPa; however, at higher pressures, these TA modes exhibit a nonmonotonic behavior and soften unexpectedly. When further taking into account the phonon coupling effects, these TA modes stiffen with increasing temperature. The competing effects of the pressure-induced softening and the temperature-induced stiffening of these TA modes may be related to the anomalous melting behavior of sodium under high pressures.

掲載誌

Physical Chemistry Chemical Physics

CiteScore: 5.5

自己引用率: 10.3%

年間論文数: 3036

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