Soft-mode dynamics in the ferroelectric phase transition of GeTe
Abstract GeTe that exhibits a strong anharmonicity and a ferroelectric phase transition between the rhombohedral and cubic structures has emerged as one of the leading thermoelectric materials. Herein, combining molecular dynamics simulations and inelastic neutron scattering measurements, the lattic...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2021-07-01
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| Series: | npj Computational Materials |
| Online Access: | https://doi.org/10.1038/s41524-021-00588-4 |
| _version_ | 1818430420546486272 |
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| author | Chen Wang Jiangtao Wu Zezhu Zeng Jan Embs Yanzhong Pei Jie Ma Yue Chen |
| author_facet | Chen Wang Jiangtao Wu Zezhu Zeng Jan Embs Yanzhong Pei Jie Ma Yue Chen |
| author_sort | Chen Wang |
| collection | DOAJ |
| description | Abstract GeTe that exhibits a strong anharmonicity and a ferroelectric phase transition between the rhombohedral and cubic structures has emerged as one of the leading thermoelectric materials. Herein, combining molecular dynamics simulations and inelastic neutron scattering measurements, the lattice dynamics in GeTe have been investigated to reveal the soft-mode mechanisms across the phase transition. We have constructed a first-principles-based machine-learning interatomic potential, which successfully captures the dynamical ferroelectric phase transition of GeTe by adopting the neural network technique. Although the low-energy acoustic phonons remain relatively unaffected at elevated temperatures, the high-energy optical, and longitudinal acoustic phonons demonstrate strong renormalizations as evidenced from the vibrational phonon spectra, which are attributed to the large anharmonicity accompanying the phase transition. Furthermore, our results reveal a nonmonotonic temperature dependence of the soft-modes beyond the perturbative regime. The insight provided by this work into the soft-modes may pave the way for further phonon engineering of GeTe and the related thermoelectrics. |
| first_indexed | 2024-12-14T15:33:08Z |
| format | Article |
| id | doaj.art-0b5f566f9e3c4c22983d5a67e52f91c0 |
| institution | Directory Open Access Journal |
| issn | 2057-3960 |
| language | English |
| last_indexed | 2024-12-14T15:33:08Z |
| publishDate | 2021-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | npj Computational Materials |
| spelling | doaj.art-0b5f566f9e3c4c22983d5a67e52f91c02022-12-21T22:55:48ZengNature Portfolionpj Computational Materials2057-39602021-07-01711710.1038/s41524-021-00588-4Soft-mode dynamics in the ferroelectric phase transition of GeTeChen Wang0Jiangtao Wu1Zezhu Zeng2Jan Embs3Yanzhong Pei4Jie Ma5Yue Chen6Department of Mechanical Engineering, The University of Hong KongKey Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong UniversityDepartment of Mechanical Engineering, The University of Hong KongLaboratory for Neutron Scattering and Imaging, Paul Scherrer InstituteInterdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji UniversityKey Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong UniversityDepartment of Mechanical Engineering, The University of Hong KongAbstract GeTe that exhibits a strong anharmonicity and a ferroelectric phase transition between the rhombohedral and cubic structures has emerged as one of the leading thermoelectric materials. Herein, combining molecular dynamics simulations and inelastic neutron scattering measurements, the lattice dynamics in GeTe have been investigated to reveal the soft-mode mechanisms across the phase transition. We have constructed a first-principles-based machine-learning interatomic potential, which successfully captures the dynamical ferroelectric phase transition of GeTe by adopting the neural network technique. Although the low-energy acoustic phonons remain relatively unaffected at elevated temperatures, the high-energy optical, and longitudinal acoustic phonons demonstrate strong renormalizations as evidenced from the vibrational phonon spectra, which are attributed to the large anharmonicity accompanying the phase transition. Furthermore, our results reveal a nonmonotonic temperature dependence of the soft-modes beyond the perturbative regime. The insight provided by this work into the soft-modes may pave the way for further phonon engineering of GeTe and the related thermoelectrics.https://doi.org/10.1038/s41524-021-00588-4 |
| spellingShingle | Chen Wang Jiangtao Wu Zezhu Zeng Jan Embs Yanzhong Pei Jie Ma Yue Chen Soft-mode dynamics in the ferroelectric phase transition of GeTe npj Computational Materials |
| title | Soft-mode dynamics in the ferroelectric phase transition of GeTe |
| title_full | Soft-mode dynamics in the ferroelectric phase transition of GeTe |
| title_fullStr | Soft-mode dynamics in the ferroelectric phase transition of GeTe |
| title_full_unstemmed | Soft-mode dynamics in the ferroelectric phase transition of GeTe |
| title_short | Soft-mode dynamics in the ferroelectric phase transition of GeTe |
| title_sort | soft mode dynamics in the ferroelectric phase transition of gete |
| url | https://doi.org/10.1038/s41524-021-00588-4 |
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