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High-pressure phase transition and lattice dynamics of rock-salt and FeSi-type phases of MgS |
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| Authors: | HaiYing Wu YaHong Chen XinFang Su ChengRong Deng Zi-Jiang Liu |
| Affiliation: | 1. School of Science, Chongqing Jiaotong University, Chongqing 400074, Chinahywu09@163.com;3. School of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China;4. School of Science, Beijing University of Civil Engineering and Architecture, Beijing 100044, China;5. School of Science, Chongqing Jiaotong University, Chongqing 400074, China;6. Department of Physics, Lanzhou City University, Lanzhou 730070, China |
| Abstract: | A phase transition of MgS under high pressure is investigated using a first-principles method. It is found from energy-volume calculations that the rock-salt (B1) phase of MgS transforms into a FeSi-type (B28) phase at 143?GPa. The calculated ground-state parameters in the B1 phase are in excellent agreement with available experimental and theoretical data. Ab initio phonon calculations are also performed to investigate the structural behaviour of MgS under high pressure. An unstable transverse acoustic mode and a phase transition from B1 to B28 phase at ~143.7?GPa driven by this soft mode are predicted. The B28 structure of MgS is stable up to 350?GPa according to lattice dynamics calculations. |
| Keywords: | semiconductor high pressure phase transition phonon dispersion MgS |